Review of potential subsurface permeable barrier emplacement and monitoring technologies

International Nuclear Information System (INIS)

Riggsbee, W.H.; Treat, R.L.; Stansfield, H.J.; Schwarz, R.M.; Cantrell, K.J.; Phillips, S.J.

1994-02-01

This report focuses on subsurface permeable barrier technologies potentially applicable to existing waste disposal sites. This report describes candidate subsurface permeable barriers, methods for emplacing these barriers, and methods used to monitor the barrier performance. Two types of subsurface barrier systems are described: those that apply to contamination.in the unsaturated zone, and those that apply to groundwater and to mobile contamination near the groundwater table. These barriers may be emplaced either horizontally or vertically depending on waste and site characteristics. Materials for creating permeable subsurface barriers are emplaced using one of three basic methods: injection, in situ mechanical mixing, or excavation-insertion. Injection is the emplacement of dissolved reagents or colloidal suspensions into the soil at elevated pressures. In situ mechanical mixing is the physical blending of the soil and the barrier material underground. Excavation-insertion is the removal of a soil volume and adding barrier materials to the space created. Major vertical barrier emplacement technologies include trenching-backfilling; slurry trenching; and vertical drilling and injection, including boring (earth augering), cable tool drilling, rotary drilling, sonic drilling, jetting methods, injection-mixing in drilled holes, and deep soil mixing. Major horizontal barrier emplacement technologies include horizontal drilling, microtunneling, compaction boring, horizontal emplacement, longwall mining, hydraulic fracturing, and jetting methods

Online monitoring of food processes using subsurface laser scattering

DEFF Research Database (Denmark)

Carstensen, Jens Michael; Møller, Flemming

Online monitoring of physical parameters during food production is not a trivial task, but promising results can often be obtained with Subsurface Laser Scattering (SLS). The first SLS instruments are on the market today, and studies are needed to asses the potential of the technology. SLS can mo...... of the SLS technology is explained, and results from yoghurt fermentation and foaming of a dairy dessert product is presented....

Development of anomaly detection models for deep subsurface monitoring

Science.gov (United States)

Sun, A. Y.

2017-12-01

Deep subsurface repositories are used for waste disposal and carbon sequestration. Monitoring deep subsurface repositories for potential anomalies is challenging, not only because the number of sensor networks and the quality of data are often limited, but also because of the lack of labeled data needed to train and validate machine learning (ML) algorithms. Although physical simulation models may be applied to predict anomalies (or the system's nominal state for that sake), the accuracy of such predictions may be limited by inherent conceptual and parameter uncertainties. The main objective of this study was to demonstrate the potential of data-driven models for leakage detection in carbon sequestration repositories. Monitoring data collected during an artificial CO2 release test at a carbon sequestration repository were used, which include both scalar time series (pressure) and vector time series (distributed temperature sensing). For each type of data, separate online anomaly detection algorithms were developed using the baseline experiment data (no leak) and then tested on the leak experiment data. Performance of a number of different online algorithms was compared. Results show the importance of including contextual information in the dataset to mitigate the impact of reservoir noise and reduce false positive rate. The developed algorithms were integrated into a generic Web-based platform for real-time anomaly detection.

Remote real-time monitoring of subsurface landfill gas migration.

Science.gov (United States)

Fay, Cormac; Doherty, Aiden R; Beirne, Stephen; Collins, Fiachra; Foley, Colum; Healy, John; Kiernan, Breda M; Lee, Hyowon; Maher, Damien; Orpen, Dylan; Phelan, Thomas; Qiu, Zhengwei; Zhang, Kirk; Gurrin, Cathal; Corcoran, Brian; O'Connor, Noel E; Smeaton, Alan F; Diamond, Dermot

2011-01-01

The cost of monitoring greenhouse gas emissions from landfill sites is of major concern for regulatory authorities. The current monitoring procedure is recognised as labour intensive, requiring agency inspectors to physically travel to perimeter borehole wells in rough terrain and manually measure gas concentration levels with expensive hand-held instrumentation. In this article we present a cost-effective and efficient system for remotely monitoring landfill subsurface migration of methane and carbon dioxide concentration levels. Based purely on an autonomous sensing architecture, the proposed sensing platform was capable of performing complex analytical measurements in situ and successfully communicating the data remotely to a cloud database. A web tool was developed to present the sensed data to relevant stakeholders. We report our experiences in deploying such an approach in the field over a period of approximately 16 months.

The Effect of Different Subsurface Drainage Systems on Improvement of Water Flow in Paddy fields

Directory of Open Access Journals (Sweden)

ghassem aghajani mazandarani

2017-03-01

Full Text Available Introduction: Better use of water and soil resources in paddy fields, increase in rice production and farmer's income, installation of subsurface drainage system is necessary. The main goalof these systems, are aeration conditions improvement prevention of water logging, yield increase, land use increase and multiuse of the land. In different countries, installation of subsurface drainage cause yield increase and working condition on the land, but no research has been conducted in different depths and spacing. On the other hand, spacing and depth are the most important parameters in the installation of drainage systems, have a direct effect on incoming water into the drains. The aim of this research, is an investigation of the effect of subsurface drainage with different depths and spacing on discharge rate variation and water table fall, in order to analyze the improvement of water flow movement in the soil. Also, study the effect of different drainage systems on the increase of the canola yield as the second cultivation in these treatments have been compared. Materials and Methods: To measure hydraulic conductivity in different depths, the auger holes have been dug (excavated. The saturated hydraulic conductivity in these holes wasdetermined using Ernst method (1950 before installation of drainage systems. In the drainage pilot plot of Sari Agricultural Sciences and Natural Resources University three subsurface drainage systems with mineral envelope have been installed. 1- The first one with the 0.9 m depth and 30 m spacing (D90 L30, 2- The second one with 0.65 m depth and 15 m spacing (D0.65 L15 and 3- The third one with 0.65 m depth and spacing (D0.65 L30 and one bi-level system with mineral envelope including four drains of 15 m spacing with 0.9 m and 0.65 m depths were installed alternatively. After auger hole equipment installations, in the middle spacing of two subsurface and water table reading possible, the water table fluctuation and

An experimental approach to determining subsurface leakage from a surface impoundment using a radioisotope tracer

International Nuclear Information System (INIS)

Ashwood, T.L.; Story, J.D.; Larsen, I.L.; Schultz, F.J.

1987-01-01

Bromine-82, a 35.3-h half-life radionuclide, was used as a tracer to determine the paths and rates of leakage from an unlined, 1,000,000-gal (3,785,000 L), surface impoundment at the Oak Ridge National Laboratory. Since the impoundment is underlain and surrounded by storm sewer and sanitary sewer lines (most of them predating the impoundment), known and suspected leak sites in storm drain catch basins and sanitary sewer manholes were sampled periodically and analyzed for 82 Br. A series of four ground water monitoring wells - three downgradient and one upgradient from the impoundment - were also sampled for 82 Br. Although the catch basin and manhole samples picked up 82 Br in leakage from the impoundment less than 5 h after application of the tracer, the monitoring well samples did not contain detectable levels of the radionuclide. It was concluded that the monitoring wells were sampling groundwater moving through the formation, whereas the storm drains and manholes were sampling water leading rapidly through secondary porosity and along preferred pathways. The decline in tracer concentration as a function of time was used to determine the residence time of water in the pond and hence the flow rate through the pond. This flow rate, when compared with the known outflow rate, indicated that the leakage flow was small. Hence, the main value of the test was to identify rapid leakage pathways. The experiment demonstrates the need for sampling subsurface drain systems as part of an integrated monitoring system for leak detection. The effectiveness of 82 Br as a tracer for rapid leaks was also shown

Assessing coastal plain risk indices for subsurface phosphorus loss

Science.gov (United States)

Phosphorus (P) Indices are important tools for nutrient management planning in the U.S. whose evaluation often has been deemphasized in favor of research and development. Assessing P Indices in artificially drained agroecosystems is especially important, as subsurface flow is the predominant mode of...

Environmental monitoring of subsurface low-level waste disposal facilities at Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Ashwood, T.L.; Hicks, D.S.

1992-01-01

Oak Ridge National Laboratory (ORNL) generates low-level waste (LLW) as part of its research and isotope production activities. This waste is managed in accordance with US Department of Energy (DOE) Order 5820.2A. Solid LLW management includes disposal in above-ground, tumulus-type facilities as well as in various types of subsurface facilities. Since 1986, subsurface disposal has been conducted using various designs employing greater-confinement-disposal (GCD) techniques. The purpose of this paper is to present monitoring results that document the short-term performance of these GCD facilities

Subsurface phosphorus transport through a no-till field in the semi arid Palouse region

Science.gov (United States)

Norby, J. C.; Brooks, E. S.; Strawn, D. G.

2017-12-01

Excess application of fertilizers containing nitrogen and phosphorus for farming use has led to ongoing water quality issues in the United States. When these nutrients leave agronomic systems, and enter water bodies in large quantities, algal bloom and eutrophication can occur. Extensive studies focusing on phosphorus as a pollutant from agronomic systems have been conducted in the many regions of the United States; however, there has been a lack of studies completed in the semiarid Palouse region of eastern Washington and western Idaho. The goal of this research study was to better understand how no-till farm management has altered soil P temporally and the current availability for off-site transport of P throughout an artificially drained catchment at the Cook Agronomy Farm in Pullman, WA. We also attempted to determine the processes responsible for subsurface flow of phosphorus, specifically through preferential flow pathways. Dissolved reactive P (DRP)concentrations of subsurface drainage from a artificial drain exceeded TMDL threshold concentrations during numerous seasonal high flow events over the two-year study time frame. Soil analyses show a highly variable distribution of water-extractable P across the sub-catchment area and initial results suggest a translocation of P species deeper into the soil profile after implementing no-till practices in 1998. We hypothesized that a greater network of macropores from lack of soil disturbance allow for preferential flow of nutrient-laden water deeper into the subsurface and to the artificial drain system. Simulated flow experiments on soil cores from the study site showed large-scale macropore development, extreme variability in soil conductivity, and high P adsorption potential for the soils, suggesting a disconnect between P movement through macropore soil and subsurface drainage water rich in DRP at the artificial drain line outlet.

Integrating real-time subsurface hydrologic monitoring with empirical rainfall thresholds to improve landslide early warning

Science.gov (United States)

Mirus, Benjamin B.; Becker, Rachel E.; Baum, Rex L.; Smith, Joel B.

2018-01-01

Early warning for rainfall-induced shallow landsliding can help reduce fatalities and economic losses. Although these commonly occurring landslides are typically triggered by subsurface hydrological processes, most early warning criteria rely exclusively on empirical rainfall thresholds and other indirect proxies for subsurface wetness. We explore the utility of explicitly accounting for antecedent wetness by integrating real-time subsurface hydrologic measurements into landslide early warning criteria. Our efforts build on previous progress with rainfall thresholds, monitoring, and numerical modeling along the landslide-prone railway corridor between Everett and Seattle, Washington, USA. We propose a modification to a previously established recent versus antecedent (RA) cumulative rainfall thresholds by replacing the antecedent 15-day rainfall component with an average saturation observed over the same timeframe. We calculate this antecedent saturation with real-time telemetered measurements from five volumetric water content probes installed in the shallow subsurface within a steep vegetated hillslope. Our hybrid rainfall versus saturation (RS) threshold still relies on the same recent 3-day rainfall component as the existing RA thresholds, to facilitate ready integration with quantitative precipitation forecasts. During the 2015–2017 monitoring period, this RS hybrid approach has an increase of true positives and a decrease of false positives and false negatives relative to the previous RA rainfall-only thresholds. We also demonstrate that alternative hybrid threshold formats could be even more accurate, which suggests that further development and testing during future landslide seasons is needed. The positive results confirm that accounting for antecedent wetness conditions with direct subsurface hydrologic measurements can improve thresholds for alert systems and early warning of rainfall-induced shallow landsliding.

A Theoretical Study of Subsurface Drainage Model Simulation of ...

African Journals Online (AJOL)

A three-dimensional variable-density groundwater flow model, the SEAWAT model, was used to assess the influence of subsurface drain spacing, evapotranspiration and irrigation water quality on salt concentration at the base of the root zone, leaching and drainage in salt affected irrigated land. The study was carried out ...

Geophysical Monitoring of Coupled Microbial and Geochemical Processes During Stimulated Subsurface Bioremediation

International Nuclear Information System (INIS)

Williams, Kenneth H.; Kemna, Andreas; Wilkins, Michael J.; Druhan, Jennifer L.; Arntzen, Evan V.; N'Guessan, A. Lucie; Long, Philip E.; Hubbard, Susan S.; Banfield, Jillian F.

2009-01-01

Understanding how microorganisms alter their physical and chemical environment during bioremediation is hindered by our inability to resolve subsurface microbial activity with high spatial resolution. Here we demonstrate the use of a minimally invasive geophysical technique to monitor stimulated microbial activity during acetate amendment in an aquifer near Rifle, Colorado. During electrical induced polarization (IP) measurements, spatiotemporal variations in the phase response between imposed electric current and the resultant electric field correlated with changes in groundwater geochemistry accompanying stimulated iron and sulfate reduction and sulfide mineral precipitation. The magnitude of the phase response varied with measurement frequency (0.125 and 1 Hz) and was dependent upon the dominant metabolic process. The spectral effect was corroborated using a biostimulated column experiment containing Rifle sediments and groundwater. Fluids and sediments recovered from regions exhibiting an anomalous phase response were enriched in Fe(II), dissolved sulfide, and cell-associated FeS nanoparticles. The accumulation of mineral precipitates and electroactive ions altered the ability of pore fluids to conduct electrical charge, accounting for the anomalous IP response and revealing the usefulness of multifrequency IP measurements for monitoring mineralogical and geochemical changes accompanying stimulated subsurface bioremediation

4D ERT Monitoring of Subsurface Water Pipe Leakage During a Controlled Field Experiment

Science.gov (United States)

Inauen, C.; Chambers, J. E.; Wilkinson, P. B.; Meldrum, P.; Swift, R. T.; Uhlemann, S.; Gunn, D.; Dashwood, B.; Taxil, J.; Curioni, G.

2016-12-01

Locating and delineating leakage from subsurface pipelines is an important task for civil engineers. 4D Electrical Resistivity Tomography (ERT) allows changes in subsurface resistivity to be imaged at a high spatial and temporal resolution in a minimally invasive manner. It is therefore a promising tool to supplement conventional point-sensing techniques to monitor subsurface flow processes. To assess the efficacy of ERT for pipe leakage monitoring several controlled leak experiments were carried out at a test site in Blagdon, Bristol, UK. To simulate the leak, a plastic pipe with a hole was buried below a flat, grassed area at a depth of 0.7 m, representing a standard UK mains water pipe installation. The water table at the site lies well below the surface meaning that the experiment took entirely place in the vadose zone, where changes in resistivity are primarily sensitive to water content variations. The ERT array covered an area of 6.5m x 6.5m around the leak location. Data acquisition was carried out with the BGS PRIME (Proactive Infrastructure Monitoring and Evaluation) system, which facilitates remote scheduling and autonomous ERT data collection and transmission. To obtain the resistivity changes of the subsurface a 4D inversion was carried out using a Gauss-Newton approach with spatial and temporal smoothness constraints. We were able to reliably observe the onset, spread and cessation of the leakage. Measurements from in-situ soil sensors at several depths above and below the leak complemented the ERT data and allowed us to assess their reliability and directly relate them to hydrogeological processes. Moreover, through experimental tests with soil samples from the test area, a Waxman-Smits relation was obtained to directly convert the changes in electrical resistivity to gravimetric soil moisture content. With future experiments on the test site more work is planned towards survey optimization, automated processing and tracking of leakage plumes.

Monitoring of subsurface extended cavities prone to instabilities

Science.gov (United States)

Bigarre, Pascal; Nadim, Charles-Édouard; Lahaie, Frantz

2010-05-01

Natural or abandoned anthropogenic cavities are to be found in various contexts all around the world. In France, shallow cavities count rises up to several hundreds of thousands. It concerns complex cavities as old abandoned multilevel quarries, extended mines or naturally interlaced karsts. Risk assessment related to these cavities, such as sinkholes or pillar failure, conducts usually to short term strategy based on regular visual inspections until a more definitive risk reduction strategy is adopted. However, if no definitive remediation appears as feasible, for technical or socio-economic reasons, monitoring by regular visual inspection of specialists rises several crucial issues in the long term: safety conditions for the inspection team, limited reactivity of the monitoring due to the period between two inspections and finally difficulties to detect reliably and exhaustively early signs of evolution when local disorders are spread over a large underground area. Several well-proofed techniques are available to detect subsurface cavities, but it is less common when considering field instrumentation applied to permanent monitoring in such context. Indeed, classical geotechnical measurement based on strain and displacement sensors give very local information and cannot be deployed at a large scale with a correct coverage within a reasonable cost/benefit ratio. Moreover this type of instrumentation requires significant efforts and equipment for installation underground, must be placed right inside the most hazardous zones whenever it is feasible and is often not retrievable. Yet a continuous remote monitoring can save a regular control on site and may provide unique information about the kinetic of potential sinkholes and local ground failures. To proceed with this matter, INERIS develops and tests new tools and methods to facilitate the setting up of operational devices for remote monitoring and alert applied to subsurface extended cavities. Such systems aim to

Geoelectrical monitoring of simulated subsurface leakage to support high-hazard nuclear decommissioning at the Sellafield Site, UK

Energy Technology Data Exchange (ETDEWEB)

Kuras, Oliver, E-mail: oku@bgs.ac.uk [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Wilkinson, Paul B.; Meldrum, Philip I.; Oxby, Lucy S. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Uhlemann, Sebastian [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); ETH-Swiss Federal Institute of Technology, Institute of Geophysics, Sonneggstr. 5, 8092 Zurich (Switzerland); Chambers, Jonathan E. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom); Binley, Andrew [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom); Graham, James [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom); Smith, Nicholas T. [National Nuclear Laboratory, Central Laboratory, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom); School of Earth, Atmospheric and Environmental Sciences, Williamson Building, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Atherton, Nick [Sellafield Ltd, Albion Square, Swingpump Lane, Whitehaven CA28 7NE (United Kingdom)

2016-10-01

A full-scale field experiment applying 4D (3D time-lapse) cross-borehole Electrical Resistivity Tomography (ERT) to the monitoring of simulated subsurface leakage was undertaken at a legacy nuclear waste silo at the Sellafield Site, UK. The experiment constituted the first application of geoelectrical monitoring in support of decommissioning work at a UK nuclear licensed site. Images of resistivity changes occurring since a baseline date prior to the simulated leaks revealed likely preferential pathways of silo liquor simulant flow in the vadose zone and upper groundwater system. Geophysical evidence was found to be compatible with historic contamination detected in permeable facies in sediment cores retrieved from the ERT boreholes. Results indicate that laterally discontinuous till units forming localized hydraulic barriers substantially affect flow patterns and contaminant transport in the shallow subsurface at Sellafield. We conclude that only geophysical imaging of the kind presented here has the potential to provide the detailed spatial and temporal information at the (sub-)meter scale needed to reduce the uncertainty in models of subsurface processes at nuclear sites. - Graphical abstract: 3D fractional resistivity change (resistivity change Δρ divided by baseline resistivity ρ{sub 0}) image showing results of Stage 1 silo liquor simulant injection. The black line delineates the preferential flow path; green cylinders show regions of historic contamination found in sediment cores from ERT boreholes. - Highlights: • 4D geoelectrical monitoring at Sellafield detected and tracked simulated silo leaks. • ERT revealed likely pathways of silo liquor simulant flow in the subsurface. • The method can reduce uncertainty in subsurface process models at nuclear sites. • Has been applied in this form at a UK nuclear licensed site for the first time • Study demonstrates value of 4D geophysics for nuclear decommissioning.

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

SUBSURFACE EMPLACEMENT TRANSPORTATION SYSTEM

International Nuclear Information System (INIS)

Wilson, T.; Novotny, R.

1999-01-01

The objective of this analysis is to identify issues and criteria that apply to the design of the Subsurface Emplacement Transportation System (SET). The SET consists of the track used by the waste package handling equipment, the conductors and related equipment used to supply electrical power to that equipment, and the instrumentation and controls used to monitor and operate those track and power supply systems. Major considerations of this analysis include: (1) Operational life of the SET; (2) Geometric constraints on the track layout; (3) Operating loads on the track; (4) Environmentally induced loads on the track; (5) Power supply (electrification) requirements; and (6) Instrumentation and control requirements. This analysis will provide the basis for development of the system description document (SDD) for the SET. This analysis also defines the interfaces that need to be considered in the design of the SET. These interfaces include, but are not limited to, the following: (1) Waste handling building; (2) Monitored Geologic Repository (MGR) surface site layout; (3) Waste Emplacement System (WES); (4) Waste Retrieval System (WRS); (5) Ground Control System (GCS); (6) Ex-Container System (XCS); (7) Subsurface Electrical Distribution System (SED); (8) MGR Operations Monitoring and Control System (OMC); (9) Subsurface Facility System (SFS); (10) Subsurface Fire Protection System (SFR); (11) Performance Confirmation Emplacement Drift Monitoring System (PCM); and (12) Backfill Emplacement System (BES)

Year 3 Summary Report: Baseline Selenium Monitoring of Agricultural Drains Operated by the Imperial Irrigation District in the Salton Sea Basin

Science.gov (United States)

Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.

2008-01-01

This report summarizes findings from the third year of a 4-year-long field investigation to document selected baseline environmental conditions in 29 agricultural drains and ponds operated by the Imperial Irrigation District along the southern border of the Salton Sea. Routine water quality and fish species were measured at roughly quarterly intervals from April 2007 to January 2008. The water quality measurements included total suspended solids and total (particulate plus dissolved) selenium. In addition, during April and October 2007, water samples were collected from seven intensively monitored drains for measurement of particulate and dissolved selenium, including inorganic and organic fractions. In addition, sediment, aquatic food chain matrices (particulate organic detritus, filamentous algae, net plankton, and midge [chironomid] larvae), and two fish species (western mosquitofish, Gambusia affinis; and sailfin molly, Poecilia latipinna) were sampled from the seven drains for measurement of total selenium concentrations. The mosquitofish and mollies were intended to serve as surrogates for desert pupfish (Cyprinodon macularius), an endangered species that we were not permitted to take for selenium determinations. Water quality values were typical of surface waters in a hot desert climate. A few drains exhibited brackish, near anoxic conditions especially during the summer and fall when water temperatures occasionally exceeded 30 degrees C. In general, total selenium concentrations in water varied directly with conductivity and inversely with pH. Although desert pupfish were found in several drains, sometimes in relatively high numbers, the fish faunas of most drains and ponds were dominated by nonnative species, especially red shiner (Cyprinella lutrensis), mosquitofish, and mollies. Dissolved selenium in water samples from the seven intensively monitored drains ranged from 0.700 to 24.1 ug/L, with selenate as the major constituent in all samples. Selenium

Subsurface stormflow modeling with sensitivity analysis using a Latin-hypercube sampling technique

International Nuclear Information System (INIS)

Gwo, J.P.; Toran, L.E.; Morris, M.D.; Wilson, G.V.

1994-09-01

Subsurface stormflow, because of its dynamic and nonlinear features, has been a very challenging process in both field experiments and modeling studies. The disposal of wastes in subsurface stormflow and vadose zones at Oak Ridge National Laboratory, however, demands more effort to characterize these flow zones and to study their dynamic flow processes. Field data and modeling studies for these flow zones are relatively scarce, and the effect of engineering designs on the flow processes is poorly understood. On the basis of a risk assessment framework and a conceptual model for the Oak Ridge Reservation area, numerical models of a proposed waste disposal site were built, and a Latin-hypercube simulation technique was used to study the uncertainty of model parameters. Four scenarios, with three engineering designs, were simulated, and the effectiveness of the engineering designs was evaluated. Sensitivity analysis of model parameters suggested that hydraulic conductivity was the most influential parameter. However, local heterogeneities may alter flow patterns and result in complex recharge and discharge patterns. Hydraulic conductivity, therefore, may not be used as the only reference for subsurface flow monitoring and engineering operations. Neither of the two engineering designs, capping and French drains, was found to be effective in hydrologically isolating downslope waste trenches. However, pressure head contours indicated that combinations of both designs may prove more effective than either one alone

Final Report: Baseline Selenium Monitoring of Agricultural Drains Operated by the Imperial Irrigation District in the Salton Sea Basin, California

Science.gov (United States)

Saiki, Michael K.; Martin, Barbara A.; May, Thomas W.

2010-01-01

This report summarizes comprehensive findings from a 4-year-long field investigation to document baseline environmental conditions in 29 agricultural drains and ponds operated by the Imperial Irrigation District along the southern border of the Salton Sea. Routine water-quality collections and fish community assessments were conducted on as many as 16 sampling dates at roughly quarterly intervals from July 2005 to April 2009. The water-quality measurements included total suspended solids and total (particulate plus dissolved) selenium. With one exception, fish were surveyed with baited minnow traps at quarterly intervals during the same time period. However, in July 2007, fish surveys were not conducted because we lacked permission from the California Department of Fish and Game for incidental take of desert pupfish (Cyprinodon macularius), an endangered species. During April and October 2006-08, water samples also were collected from seven intensively monitored drains (which were selected from the 29 total drains) for measurement of particulate and dissolved selenium, including inorganic and organic fractions. In addition, sediment, aquatic food chain matrices [particulate organic detritus, filamentous algae, net plankton, and midge (chironomid) larvae], and two fish species (western mosquitofish, Gambusia affinis; and sailfin molly, Poecilia latipinna) were sampled from the seven drains for measurement of total selenium concentrations. The mosquitofish and mollies were intended to serve as surrogates for pupfish, which we were not permitted to sacrifice for selenium determinations. Water quality (temperature, dissolved oxygen, pH, specific conductance, and turbidity) values were typical of surface waters in a hot, arid climate. A few drains exhibited brackish, near-anoxic conditions, especially during summer and fall when water temperatures occasionally exceeded 30 degrees Celsius. Total selenium concentrations in water were directly correlated with salinity and

Identifying uncertainty of the mean of some water quality variables along water quality monitoring network of Bahr El Baqar drain

Directory of Open Access Journals (Sweden)

Hussein G. Karaman

2013-10-01

Full Text Available Assigning objectives to the environmental monitoring network is the pillar of the design to these kinds of networks. Conflicting network objectives may affect the adequacy of the design in terms of sampling frequency and the spatial distribution of the monitoring stations which in turn affect the accuracy of the data and the information extracted. The first step in resolving this problem is to identify the uncertainty inherent in the network as the result of the vagueness of the design objective. Entropy has been utilized and adopted over the past decades to identify uncertainty in similar water data sets. Therefore it is used to identify the uncertainties inherent in the water quality monitoring network of Bahr El-Baqar drain located in the Eastern Delta. Toward investigating the applicability of the Entropy methodology, comprehensive analysis at the selected drain as well as their data sets is carried out. Furthermore, the uncertainty calculated by the entropy function will be presented by the means of the geographical information system to give the decision maker a global view to these uncertainties and to open the door to other researchers to find out innovative approaches to lower these uncertainties reaching optimal monitoring network in terms of the spatial distribution of the monitoring stations.

Subsurface drainage

CSIR Research Space (South Africa)

Van Der

1993-09-01

Full Text Available and long term behavior were evaluated. Laboratory tests for geotextile selection are recommended and tentative criteria given. The use of fin drains was evaluated in the laboratory and a field study to monitor the efficacy of drainage systems was started...

Subsurface Ventilation System Description Document

Energy Technology Data Exchange (ETDEWEB)

Eric Loros

2001-07-25

The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

Subsurface Ventilation System Description Document

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-10-12

The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

Sensitivity analysis of the agricultural policy/environmental extender (APEX) for phosphorus loads in tile-drained landscapes

Science.gov (United States)

Numerical modeling is an economical and feasible approach for quantifying the effects of best management practices on phosphorus (P) loadings from agricultural fields. However, tools that simulate both surface and subsurface P pathways are limited and have not been robustly evaluated in tile-drained...

Geoelectrical monitoring of simulated subsurface leakage to support high-hazard nuclear decommissioning at the Sellafield Site, UK.

Science.gov (United States)

Kuras, Oliver; Wilkinson, Paul B; Meldrum, Philip I; Oxby, Lucy S; Uhlemann, Sebastian; Chambers, Jonathan E; Binley, Andrew; Graham, James; Smith, Nicholas T; Atherton, Nick

2016-10-01

A full-scale field experiment applying 4D (3D time-lapse) cross-borehole Electrical Resistivity Tomography (ERT) to the monitoring of simulated subsurface leakage was undertaken at a legacy nuclear waste silo at the Sellafield Site, UK. The experiment constituted the first application of geoelectrical monitoring in support of decommissioning work at a UK nuclear licensed site. Images of resistivity changes occurring since a baseline date prior to the simulated leaks revealed likely preferential pathways of silo liquor simulant flow in the vadose zone and upper groundwater system. Geophysical evidence was found to be compatible with historic contamination detected in permeable facies in sediment cores retrieved from the ERT boreholes. Results indicate that laterally discontinuous till units forming localized hydraulic barriers substantially affect flow patterns and contaminant transport in the shallow subsurface at Sellafield. We conclude that only geophysical imaging of the kind presented here has the potential to provide the detailed spatial and temporal information at the (sub-)meter scale needed to reduce the uncertainty in models of subsurface processes at nuclear sites. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.

SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

International Nuclear Information System (INIS)

C.J. Fernado

1998-01-01

The purpose of this document is to develop preliminary high-level functional and physical control system architectures for the proposed subsurface repository at Yucca Mountain. This document outlines overall control system concepts that encompass and integrate the many diverse systems being considered for use within the subsurface repository. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The subsurface repository design will be composed of a series of diverse systems that will be integrated to accomplish a set of overall functions and objectives. The subsurface repository contains several Instrumentation and Control (I andC) related systems including: waste emplacement systems, ventilation systems, communication systems, radiation monitoring systems, rail transportation systems, ground control monitoring systems, utility monitoring systems (electrical, lighting, water, compressed air, etc.), fire detection and protection systems, retrieval systems, and performance confirmation systems. Each of these systems involve some level of I andC and will typically be integrated over a data communication network. The subsurface I andC systems will also integrate with multiple surface-based site-wide systems such as emergency response, health physics, security and safeguards, communications, utilities and others. The scope and primary objectives of this analysis are to: (1) Identify preliminary system level functions and interface needs (Presented in the functional diagrams in Section 7.2). (2) Examine the overall system complexity and determine how and on what levels these control systems will be controlled and integrated (Presented in Section 7.2). (3) Develop a preliminary subsurface facility-wide design for an overall control system architecture, and depict this design by a series of control system functional block diagrams (Presented in Section 7.2). (4) Develop a series of physical architectures

SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

Energy Technology Data Exchange (ETDEWEB)

C.J. Fernado

1998-09-17

The purpose of this document is to develop preliminary high-level functional and physical control system architectures for the proposed subsurface repository at Yucca Mountain. This document outlines overall control system concepts that encompass and integrate the many diverse systems being considered for use within the subsurface repository. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The subsurface repository design will be composed of a series of diverse systems that will be integrated to accomplish a set of overall functions and objectives. The subsurface repository contains several Instrumentation and Control (I&C) related systems including: waste emplacement systems, ventilation systems, communication systems, radiation monitoring systems, rail transportation systems, ground control monitoring systems, utility monitoring systems (electrical, lighting, water, compressed air, etc.), fire detection and protection systems, retrieval systems, and performance confirmation systems. Each of these systems involve some level of I&C and will typically be integrated over a data communication network. The subsurface I&C systems will also integrate with multiple surface-based site-wide systems such as emergency response, health physics, security and safeguards, communications, utilities and others. The scope and primary objectives of this analysis are to: (1) Identify preliminary system level functions and interface needs (Presented in the functional diagrams in Section 7.2). (2) Examine the overall system complexity and determine how and on what levels these control systems will be controlled and integrated (Presented in Section 7.2). (3) Develop a preliminary subsurface facility-wide design for an overall control system architecture, and depict this design by a series of control system functional block diagrams (Presented in Section 7.2). (4) Develop a series of physical architectures that

2012 Groundwater Monitoring Report Central Nevada Test Area, Subsurface Corrective Action Unit 443

Energy Technology Data Exchange (ETDEWEB)

None

2013-04-01

The Central Nevada Test Area was the site of a 0.2- to 1-megaton underground nuclear test in 1968. The surface of the site has been closed, but the subsurface is still in the corrective action process. The corrective action alternative selected for the site was monitoring with institutional controls. Annual sampling and hydraulic head monitoring are conducted as part of the subsurface corrective action strategy. The site is currently in the fourth year of the 5-year proof-of-concept period that is intended to validate the compliance boundary. Analytical results from the 2012 monitoring are consistent with those of previous years. Tritium remains at levels below the laboratory minimum detectable concentration in all wells in the monitoring network. Samples collected from reentry well UC-1-P-2SR, which is not in the monitoring network but was sampled as part of supplemental activities conducted during the 2012 monitoring, indicate concentrations of tritium that are consistent with previous sampling results. This well was drilled into the chimney shortly after the detonation, and water levels continue to rise, demonstrating the very low permeability of the volcanic rocks. Water level data from new wells MV-4 and MV-5 and recompleted well HTH-1RC indicate that hydraulic heads are still recovering from installation and testing. Data from wells MV-4 and MV-5 also indicate that head levels have not yet recovered from the 2011 sampling event during which several thousand gallons of water were purged. It has been recommended that a low-flow sampling method be adopted for these wells to allow head levels to recover to steady-state conditions. Despite the lack of steady-state groundwater conditions, hydraulic head data collected from alluvial wells installed in 2009 continue to support the conceptual model that the southeast-bounding graben fault acts as a barrier to groundwater flow at the site.

Subsurface Contaminant Focus Area: Monitored Natural Attenuation (MNA)--Programmatic, Technical, and Regulatory Issues

Energy Technology Data Exchange (ETDEWEB)

Krupka, Kenneth M.; Martin, Wayne J.

2001-07-23

Natural attenuation processes are commonly used for remediation of contaminated sites. A variety of natural processes occur without human intervention at all sites to varying rates and degrees of effectiveness to attenuate (decrease) the mass, toxicity, mobility, volume, or concentration of organic and inorganic contaminants in soil, groundwater, and surface water systems. The objective of this review is to identify potential technical investments to be incorporated in the Subsurface Contaminant Focus Area Strategic Plan for monitored natural attenuation. When implemented, the technical investments will help evaluate and implement monitored natural attenuation as a remediation option at DOE sites. The outcome of this review is a set of conclusions and general recommendations regarding research needs, programmatic guidance, and stakeholder issues pertaining to monitored natural attenuation for the DOE complex.

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.

SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

International Nuclear Information System (INIS)

Randle, D.C.

2000-01-01

The primary purpose of this document is to develop a preliminary high-level functional and physical control system architecture for the potential repository at Yucca Mountain. This document outlines an overall control system concept that encompasses and integrates the many diverse process and communication systems being developed for the subsurface repository design. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The Subsurface Repository Integrated Control System design will be composed of a series of diverse process systems and communication networks. The subsurface repository design contains many systems related to instrumentation and control (I andC) for both repository development and waste emplacement operations. These systems include waste emplacement, waste retrieval, ventilation, radiological and air monitoring, rail transportation, construction development, utility systems (electrical, lighting, water, compressed air, etc.), fire protection, backfill emplacement, and performance confirmation. Each of these systems involves some level of I andC and will typically be integrated over a data communications network throughout the subsurface facility. The subsurface I andC systems will also interface with multiple surface-based systems such as site operations, rail transportation, security and safeguards, and electrical/piped utilities. In addition to the I andC systems, the subsurface repository design also contains systems related to voice and video communications. The components for each of these systems will be distributed and linked over voice and video communication networks throughout the subsurface facility. The scope and primary objectives of this design analysis are to: (1) Identify preliminary system-level functions and interfaces (Section 6.2). (2) Examine the overall system complexity and determine how and on what levels the engineered process systems will be monitored

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.

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...

Subsurface irrigation of potato crop (Solanum tuberosum ssp. Andigena) in Suka Kollus with different drainage systems

Science.gov (United States)

Serrano-Coronel, Genaro; Chipana-Rivera, René; Fátima Moreno-Pérez, María; Roldán-Cañas, José

2016-04-01

Among the most important hydraulic structures of pre-Hispanic ancestral technology developed in the Andean region, we find the suka kollus, aymara word, called also waru waru, en quechua or raised fields, in English. They are raised platforms surrounded by water canals that irrigate subsurface, but also have the function of draining, to deal with floods because they are surrounding Lake Titicaca. They also have the property of generating a thermoregulatory effect to crops, depending on the configuration of the channels and platforms. Such agro-ecosystems are being abandoned, however, if properly addressed crop management and some drainage canals are replaced by underground drains for increased crop area could be very useful in enabling marginal soils affected by salts and / or excess water. For these reasons, the objective of this study was to evaluate the subsurface irrigation in the potato crop in suka kollus under a system of surface drainage, and mixed drainage (surface and subsurface). The study was conducted in marginal soils of Kallutaca area, located 30 km from the city of La Paz, Bolivia, at a height of 3892 m.a.s.l. The cultivation of the potato (Solanum tuberosum ssp. Andigena) was used. Four treatments were tested with different widths of the platforms: T1 (Control) with drainage through channels; T2 (replacing a channel by a drain); T3 (replacing two channels by two drains); T4 (replacing three channels by three drains). The flow of water into the soil from the water table was predominantly upward, except during periods of high rainfall. In terms of treatments, the flow in T1 was higher, mainly at weeks 8 to 11 after seedling emergence, coinciding with the phenological phases of flowering and at the beginning of the tuber ripening. It was followed by T3, T2 and T4 treatments, respectively. Tuber yield, if one considers that the channels detract arable land, was higher in the T3 treatment,16.4 Mg / ha, followed by T2 treatment, 15.2 Mg / ha, T1

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.

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.

Evaluation of SCS-CN method using a fully distributed physically based coupled surface-subsurface flow model

Science.gov (United States)

Shokri, Ali

2017-04-01

The hydrological cycle contains a wide range of linked surface and subsurface flow processes. In spite of natural connections between surface water and groundwater, historically, these processes have been studied separately. The current trend in hydrological distributed physically based model development is to combine distributed surface water models with distributed subsurface flow models. This combination results in a better estimation of the temporal and spatial variability of the interaction between surface and subsurface flow. On the other hand, simple lumped models such as the Soil Conservation Service Curve Number (SCS-CN) are still quite common because of their simplicity. In spite of the popularity of the SCS-CN method, there have always been concerns about the ambiguity of the SCS-CN method in explaining physical mechanism of rainfall-runoff processes. The aim of this study is to minimize these ambiguity by establishing a method to find an equivalence of the SCS-CN solution to the DrainFlow model, which is a fully distributed physically based coupled surface-subsurface flow model. In this paper, two hypothetical v-catchment tests are designed and the direct runoff from a storm event are calculated by both SCS-CN and DrainFlow models. To find a comparable solution to runoff prediction through the SCS-CN and DrainFlow, the variance between runoff predictions by the two models are minimized by changing Curve Number (CN) and initial abstraction (Ia) values. Results of this study have led to a set of lumped model parameters (CN and Ia) for each catchment that is comparable to a set of physically based parameters including hydraulic conductivity, Manning roughness coefficient, ground surface slope, and specific storage. Considering the lack of physical interpretation in CN and Ia is often argued as a weakness of SCS-CN method, the novel method in this paper gives a physical explanation to CN and Ia.

Subsurface Facility System Description Document

International Nuclear Information System (INIS)

Eric Loros

2001-01-01

The Subsurface Facility System encompasses the location, arrangement, size, and spacing of the underground openings. This subsurface system includes accesses, alcoves, and drifts. This system provides access to the underground, provides for the emplacement of waste packages, provides openings to allow safe and secure work conditions, and interfaces with the natural barrier. This system includes what is now the Exploratory Studies Facility. The Subsurface Facility System physical location and general arrangement help support the long-term waste isolation objectives of the repository. The Subsurface Facility System locates the repository openings away from main traces of major faults, away from exposure to erosion, above the probable maximum flood elevation, and above the water table. The general arrangement, size, and spacing of the emplacement drifts support disposal of the entire inventory of waste packages based on the emplacement strategy. The Subsurface Facility System provides access ramps to safely facilitate development and emplacement operations. The Subsurface Facility System supports the development and emplacement operations by providing subsurface space for such systems as ventilation, utilities, safety, monitoring, and transportation

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.

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.

A multi-modal geological investigation framework for subsurface modeling and kinematic monitoring of a slow-moving landslide complex in Colorado, United States

Science.gov (United States)

Lowry, B. W.; Zhou, W.; Smartgeo

2010-12-01

The Muddy Creek landslide complex is a large area of active and reactivating landslides that impact the operation of both a state highway and Paonia Reservoir in Gunnison County, Colorado, United States. Historically, the monitoring of this slide has been investigated using disparate techniques leading to protracted analysis and project knowledge attrition. We present an integrated, data-driven investigation framework that supports continued kinematic monitoring, document cataloging, and subsurface modeling of the landslide complex. A geospatial information system (GIS) was integrated with a visual programming based subsurface model to facilitate modular integration of monitoring data with borehole information. Subsurface modeling was organized by material type and activity state based on multiple sources of kinematic measurement. The framework is constructed to modularly integrate remotely sensed imagery and other spatial datasets such as ASTER, InSAR, and LiDAR derived elevation products as more precise datasets become available. The framework allows for terrestrial LiDAR survey error estimation, borehole siting, and placement of wireless sensor (GPS, accelerometers, geophysical ) networks for optimized spatial relevance and utility. Coordinated spatial referencing within the GIS facilitates geotechnical and hydrogeological modeling input generation and common display of modeling outputs. Kinematic data fusion techniques are accomplished with integration of instrumentation, surficial feature tracking, subsurface classification, and 3D interpolation. The framework includes dynamic decision support including landslide dam failure estimates, back-flooding scenario planning that can be accessed by multiple agencies and stakeholders.

2015 Groundwater Monitoring Report Project Shoal Area: Subsurface Correction Unit 447

Energy Technology Data Exchange (ETDEWEB)

Findlay, Rick [Navarro Research and Engineering, Oak Ridge, TN (United States)

2016-04-01

The Project Shoal Area in Nevada was the site of a 12-kiloton-yield underground nuclear test in 1963. Although the surface of the site has been remediated, investigation of groundwater contamination resulting from the test is still in the corrective action process. Annual sampling and hydraulic head monitoring are conducted at the site as part of the subsurface corrective action strategy. The corrective action strategy is currently focused on revising the site conceptual model (SCM) and evaluating the adequacy of the monitoring well network. Some aspects of the SCM are known; however, two major concerns are the uncertainty in the groundwater flow direction and the cause of rising water levels in site wells west of the shear zone. Water levels have been rising in the site wells west of the shear zone since the first hydrologic characterization wells were installed in 1996. Although water levels in wells west of the shear zone continue to rise, the rate of increase is less than in previous years. The SCM will be revised, and an evaluation of the groundwater monitoring network will be conducted when water levels at the site have stabilized to the agreement of both the U.S. Department of Energy Office of Legacy Management and the Nevada Division of Environmental Protection.

Invited Article: In situ comparison of passive radon-thoron discriminative monitors at subsurface workplaces in Hungary

Science.gov (United States)

Kávási, Norbert; Vigh, Tamás; Németh, Csaba; Ishikawa, Tetsuo; Omori, Yasutaka; Janik, Miroslaw; Yonehara, Hidenori

2014-02-01

During a one-year long measurement period, radon and thoron data obtained by two different passive radon-thoron discriminative monitors were compared at subsurface workplaces in Hungary, such as mines (bauxite and manganese ore) and caves (medical and touristic). These workplaces have special environmental conditions, such as, stable and high relative humidity (100%), relatively stable temperature (12°C-21°C), low or high wind speed (max. 2.4 m s-1) and low or elevated aerosol concentration (130-60 000 particles m-3). The measured radon and thoron concentrations fluctuated in a wide range among the different workplaces. The respective annual average radon concentrations and their standard deviations (in brackets) measured by the passive radon-thoron discriminative monitor with cellulose filter (CF) and the passive radon-thoron discriminative monitor with sponge filter (SF) were: 350(321) Bq m-3 and 550(497) Bq m-3 in the bauxite mine; 887(604) Bq m-3 and 1258(788) Bq m-3 in the manganese ore mine; 2510(2341) Bq m-3 and 3403(3075) Bq m-3 in the medical cave (Hospital Cave of Tapolca); and 6239(2057) Bq m-3 and 8512(1955) Bq m-3 in the touristic cave (Lake Cave of Tapolca). The respective average thoron concentrations and their standard deviation (in brackets) measured by CF and SF monitors were: 154(210) Bq m-3 and 161(148) Bq m-3 in the bauxite mine; 187(191) Bq m-3 and 117(147) Bq m-3 in the manganese-ore mine; 360(524) Bq m-3 and 371(789) Bq m-3 in the medical cave (Hospital Cave of Tapolca); and 1420(1184) Bq m-3 and 1462(3655) Bq m-3 in the touristic cave (Lake Cave of Tapolca). Under these circumstances, comparison of the radon data for the SF and CF monitors showed the former were consistently 51% higher in the bauxite mine, 38% higher in the manganese ore mine, and 34% higher in the caves. Consequently, correction is required on previously obtained radon data acquired by CF monitors at subsurface workplaces to gain comparable data for SF monitors. In the

Burial ground as a containment system: 25 years of subsurface monitoring at the Savannah River Plant Facility

International Nuclear Information System (INIS)

Fenimore, J.W.

1982-01-01

As the Savannah River Plant (SRP) solid wastes containing small quantities of radionuclides are buried in shallow (20' deep) trenches. The hydrogeology of the burial site is described together with a variety of subsurface monitoring techniques employed to ensure the continued safe operation of this disposal facility. conclusions from over two decades of data collection are presented

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)

Stable and Variable Parts of Microbial Community in Siberian Deep Subsurface Thermal Aquifer System Revealed in a Long-Term Monitoring Study

OpenAIRE

Frank, Yulia A.; Kadnikov, Vitaly V.; Gavrilov, Sergey N.; Banks, David; Gerasimchuk, Anna L.; Podosokorskaya, Olga A.; Merkel, Alexander Y.; Chernyh, Nikolai A.; Mardanov, Andrey V.; Ravin, Nikolai V.; Karnachuk, Olga V.; Bonch-Osmolovskaya, Elizaveta A.

2016-01-01

The goal of this work was to study the diversity of microorganisms inhabiting a deep subsurface aquifer system in order to understand their functional roles and interspecies relations formed in the course of buried organic matter degradation. A microbial community of a deep subsurface thermal aquifer in the Tomsk Region, Western Siberia was monitored over the course of five years via a 2.7 km deep borehole 3P, drilled down to a Palaeozoic basement. The borehole water discharges with a tempera...

The Development of a Sub-Surface Monitoring System for Organic Contamination in Soils and Groundwater

Directory of Open Access Journals (Sweden)

Sharon L. Huntley

2002-01-01

Full Text Available A major problem when dealing with environmental contamination is the early detection and subsequent surveillance of the contamination. This paper describes the potential of sub-surface sensor technology for the early detection of organic contaminants in contaminated soils, sediments, and landfill sites. Rugged, low-power hydrocarbon sensors have been developed, along with a data-logging system, for the early detection of phase hydrocarbons in soil. Through laboratory-based evaluation, the ability of this system to monitor organic contamination in water-based systems is being evaluated. When used in conjunction with specific immunoassays, this can provide a sensitive and low-cost solution for long-term monitoring and analysis, applicable to a wide range of field applications.

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.

Invited Article: In situ comparison of passive radon-thoron discriminative monitors at subsurface workplaces in Hungary

International Nuclear Information System (INIS)

Kávási, Norbert; Vigh, Tamás; Németh, Csaba; Ishikawa, Tetsuo; Omori, Yasutaka; Janik, Miroslaw; Yonehara, Hidenori

2014-01-01

During a one-year long measurement period, radon and thoron data obtained by two different passive radon-thoron discriminative monitors were compared at subsurface workplaces in Hungary, such as mines (bauxite and manganese ore) and caves (medical and touristic). These workplaces have special environmental conditions, such as, stable and high relative humidity (100%), relatively stable temperature (12°C–21°C), low or high wind speed (max. 2.4 m s −1 ) and low or elevated aerosol concentration (130–60 000 particles m −3 ). The measured radon and thoron concentrations fluctuated in a wide range among the different workplaces. The respective annual average radon concentrations and their standard deviations (in brackets) measured by the passive radon-thoron discriminative monitor with cellulose filter (CF) and the passive radon-thoron discriminative monitor with sponge filter (SF) were: 350(321) Bq m −3 and 550(497) Bq m −3 in the bauxite mine; 887(604) Bq m −3 and 1258(788) Bq m −3 in the manganese ore mine; 2510(2341) Bq m −3 and 3403(3075) Bq m −3 in the medical cave (Hospital Cave of Tapolca); and 6239(2057) Bq m −3 and 8512(1955) Bq m −3 in the touristic cave (Lake Cave of Tapolca). The respective average thoron concentrations and their standard deviation (in brackets) measured by CF and SF monitors were: 154(210) Bq m −3 and 161(148) Bq m −3 in the bauxite mine; 187(191) Bq m −3 and 117(147) Bq m −3 in the manganese-ore mine; 360(524) Bq m −3 and 371(789) Bq m −3 in the medical cave (Hospital Cave of Tapolca); and 1420(1184) Bq m −3 and 1462(3655) Bq m −3 in the touristic cave (Lake Cave of Tapolca). Under these circumstances, comparison of the radon data for the SF and CF monitors showed the former were consistently 51% higher in the bauxite mine, 38% higher in the manganese ore mine, and 34% higher in the caves. Consequently, correction is required on previously obtained radon data acquired by CF

Invited Article: In situ comparison of passive radon-thoron discriminative monitors at subsurface workplaces in Hungary

Energy Technology Data Exchange (ETDEWEB)

Kávási, Norbert, E-mail: norbert@fml.nirs.go.jp [National Institute of Radiological Sciences, Chiba (Japan); Social Organization for Radioecological Cleanliness, Veszprém (Hungary); Vigh, Tamás [Social Organization for Radioecological Cleanliness, Veszprém (Hungary); Manganese Mining Process Ltd., Úrkút (Hungary); Németh, Csaba [Social Organization for Radioecological Cleanliness, Veszprém (Hungary); University of Pannonia, Veszprém (Hungary); Ishikawa, Tetsuo; Omori, Yasutaka; Janik, Miroslaw; Yonehara, Hidenori [National Institute of Radiological Sciences, Chiba (Japan)

2014-02-15

During a one-year long measurement period, radon and thoron data obtained by two different passive radon-thoron discriminative monitors were compared at subsurface workplaces in Hungary, such as mines (bauxite and manganese ore) and caves (medical and touristic). These workplaces have special environmental conditions, such as, stable and high relative humidity (100%), relatively stable temperature (12°C–21°C), low or high wind speed (max. 2.4 m s{sup −1}) and low or elevated aerosol concentration (130–60 000 particles m{sup −3}). The measured radon and thoron concentrations fluctuated in a wide range among the different workplaces. The respective annual average radon concentrations and their standard deviations (in brackets) measured by the passive radon-thoron discriminative monitor with cellulose filter (CF) and the passive radon-thoron discriminative monitor with sponge filter (SF) were: 350(321) Bq m{sup −3} and 550(497) Bq m{sup −3} in the bauxite mine; 887(604) Bq m{sup −3} and 1258(788) Bq m{sup −3} in the manganese ore mine; 2510(2341) Bq m{sup −3} and 3403(3075) Bq m{sup −3} in the medical cave (Hospital Cave of Tapolca); and 6239(2057) Bq m{sup −3} and 8512(1955) Bq m{sup −3} in the touristic cave (Lake Cave of Tapolca). The respective average thoron concentrations and their standard deviation (in brackets) measured by CF and SF monitors were: 154(210) Bq m{sup −3} and 161(148) Bq m{sup −3} in the bauxite mine; 187(191) Bq m{sup −3} and 117(147) Bq m{sup −3} in the manganese-ore mine; 360(524) Bq m{sup −3} and 371(789) Bq m{sup −3} in the medical cave (Hospital Cave of Tapolca); and 1420(1184) Bq m{sup −3} and 1462(3655) Bq m{sup −3} in the touristic cave (Lake Cave of Tapolca). Under these circumstances, comparison of the radon data for the SF and CF monitors showed the former were consistently 51% higher in the bauxite mine, 38% higher in the manganese ore mine, and 34% higher in the caves

Comment vieillissent les géofiltres ? Auscultation du dispositif expérimental de Roissard Geofilters ageing – Monitoring of Roissard expérimental draining trenches

Directory of Open Access Journals (Sweden)

FAURE, Yves-Henri ; VERSTAEVEL, Matthieu ; MERIAUX, Patrice ; VEYLON, Guillaume ; BARTHE, Matthieu ; BERTRAND, Cécile

2012-08-01

Full Text Available Les risques liés au vieillissement des géotextiles-filtres utilisés dans les ouvrages de drainage sont un enjeu majeur pour l’ingénierie des glissements de terrain et des ouvrages hydrauliques. Le projet DrainAgeing vise à mieux comprendre les phénomènes de vieillissement par colmatage de ces matériaux afin de mieux les prévenir et de formuler des recommandations pour les concepteurs et gestionnaires d’ouvrages.Risks related to geofilters ageing used in drainage are very important in the context of landslides stabilization engineering and dams and dikes design. “DrainAgeing” research project aims to a better understanding and prevention of drains ageing and clogging. This paper is about the state of progress of the project and the results of 18 years monitoring of Roissard experimental draining trenches. We conclude about the excavation and the analysis of geotextiles and geomaterials recently performed within the context of the second phase of the project.

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....

Effects of tillage and application rate on atrazine transport to subsurface drainage: Evaluation of RZWQM using a six-year field study

Science.gov (United States)

Malone, Robert W.; Nolan, Bernard T.; Ma, Liwang; Kanwar, Rameshwar S.; Pederson, Carl H.; Heilman, Philip

2014-01-01

Well tested agricultural system models can improve our understanding of the water quality effects of management practices under different conditions. The Root Zone Water Quality Model (RZWQM) has been tested under a variety of conditions. However, the current model's ability to simulate pesticide transport to subsurface drain flow over a long term period under different tillage systems and application rates is not clear. Therefore, we calibrated and tested RZWQM using six years of data from Nashua, Iowa. In this experiment, atrazine was spring applied at 2.8 (1990–1992) and 0.6 kg/ha/yr (1993–1995) to two 0.4 ha plots with different tillage (till and no-till). The observed and simulated average annual flow weighted atrazine concentrations (FWAC) in subsurface drain flow from the no-till plot were 3.7 and 3.2 μg/L, respectively for the period with high atrazine application rates, and 0.8 and 0.9 μg/L, respectively for the period with low application rates. The 1990–1992 observed average annual FWAC difference between the no-till and tilled plot was 2.4 μg/L while the simulated difference was 2.1 μg/L. These observed and simulated differences for 1993–1995 were 0.1 and 0.1 μg/L, respectively. The Nash–Sutcliffe model performance statistic (EF) for cumulative atrazine flux to subsurface drain flow was 0.93 for the no-till plot testing years (1993–1995), which is comparable to other recent model tests. The value of EF is 1.0 when simulated data perfectly match observed data. The order of selected parameter sensitivity for RZWQM simulated FWAC was atrazine partition coefficient > number of macropores > atrazine half life in soil > soil hydraulic conductivity. Simulations from 1990 to 1995 with four different atrazine application rates applied at a constant rate throughout the simulation period showed concentrations in drain flow for the no-till plot to be twice those of the tilled plot. The differences were more pronounced in the early

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.)

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.

Geophysical characterization of subsurface barriers

International Nuclear Information System (INIS)

Borns, D.J.

1995-08-01

An option for controlling contaminant migration from plumes and buried waste sites is to construct a subsurface barrier of a low-permeability material. The successful application of subsurface barriers requires processes to verify the emplacement and effectiveness of barrier and to monitor the performance of a barrier after emplacement. Non destructive and remote sensing techniques, such as geophysical methods, are possible technologies to address these needs. The changes in mechanical, hydrologic and chemical properties associated with the emplacement of an engineered barrier will affect geophysical properties such a seismic velocity, electrical conductivity, and dielectric constant. Also, the barrier, once emplaced and interacting with the in situ geologic system, may affect the paths along which electrical current flows in the subsurface. These changes in properties and processes facilitate the detection and monitoring of the barrier. The approaches to characterizing and monitoring engineered barriers can be divided between (1) methods that directly image the barrier using the contrasts in physical properties between the barrier and the host soil or rock and (2) methods that reflect flow processes around or through the barrier. For example, seismic methods that delineate the changes in density and stiffness associated with the barrier represents a direct imaging method. Electrical self potential methods and flow probes based on heat flow methods represent techniques that can delineate the flow path or flow processes around and through a barrier

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.

The migration and monitoring of viscous NAPLs (coal tar and creosote) in the subsurface

Energy Technology Data Exchange (ETDEWEB)

Jackson, R. [Intera Engineering Ltd., Heidelberg, ON (Canada)

2009-07-01

The high viscosity of nonaqueous phase liquids (NAPLs) such as creosote and coal tar complicates efforts to monitor their mobility at contaminated sites. Viscous NAPLs can remain mobile for many decades after their application as a wood preservative, or after the closure of the facilities in which they were generated. NAPL-wet pathways in the subsurface can also lead to errors in residual saturation measurements. This abstract discussed issues related to creeping flow and the low seepage rates that are not accounted for using traditional measuring methods. Examples of creeping flow and the monitoring techniques used to assess it were presented for sites in British Columbia and Florida. The drainage of viscous NAPLs during water table declines was also considered, and a case study of a coal tar-removal procedures using polymer surfactant flooding was presented.

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

Feasibility of a subsurface storage

International Nuclear Information System (INIS)

1998-11-01

This report analyses the notion of subsurface storage under the scientifical, technical and legal aspects. This reflection belongs to the studies about long duration storage carried out in the framework of the axis 3 of the December 30, 1991 law. The report comprises 3 parts. The first part is a synthesis of the complete subsurface storage study: definitions, aim of the report, very long duration storage paradigm, description files of concepts, thematic synthesis (legal aspects, safety, monitoring, sites, seismicity, heat transfers, corrosion, concretes, R and works, handling, tailings and dismantlement, economy..), multi-criteria/multi-concept cross-analysis. The second part deals with the technical aspects of the subsurface storage: safety approach (long duration impact, radiation protection, mastery of effluents), monitoring strategy, macroscopic inventory of B-type waste packages, inventory of spent fuels, glasses, hulls and nozzles, geological contexts in the French territory (sites selection and characterization), on-site activities, hydrogeological and geochemical aspects, geo-technical works and infrastructures organization, subsurface seismic effects, cooling modes (ventilation, heat transfer with the geologic environment), heat transfer research programs (convection, poly-phase cooling in porous media), handling constraints, concretes (use, behaviour, durability), corrosion of metallic materials, technical-economical analysis, international context (experience feedback from Sweden (CLAB) and the USA (Yucca Mountain), other European and French facilities). The last part of the report is a graphical appendix with 3-D views and schemes of the different concepts. (J.S.)

Pacific Reef Assessment and Monitoring Program: Subsurface Temperature Recorders (STRs) at selected coral reef locations across the Pacific Ocean from 2001 to 2012

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

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.

Subsurface clade of Geobacteraceae that predominates in a diversity of Fe(III)-reducing subsurface environments

Science.gov (United States)

Holmes, Dawn E.; O'Neil, Regina A.; Vrionis, Helen A.; N'Guessan, Lucie A.; Ortiz-Bernad, Irene; Larrahondo, Maria J.; Adams, Lorrie A.; Ward, Joy A.; Nicoll , Julie S.; Nevin, Kelly P.; Chavan, Milind A.; Johnson, Jessica P.; Long, Philip E.; Lovely, Derek R.

2007-01-01

There are distinct differences in the physiology of Geobacter species available in pure culture. Therefore, to understand the ecology of Geobacter species in subsurface environments, it is important to know which species predominate. Clone libraries were assembled with 16S rRNA genes and transcripts amplified from three subsurface environments in which Geobacter species are known to be important members of the microbial community: (1) a uranium-contaminated aquifer located in Rifle, CO, USA undergoing in situ bioremediation; (2) an acetate-impacted aquifer that serves as an analog for the long-term acetate amendments proposed for in situ uranium bioremediation and (3) a petroleum-contaminated aquifer in which Geobacter species play a role in the oxidation of aromatic hydrocarbons coupled with the reduction of Fe(III). The majority of Geobacteraceae 16S rRNA sequences found in these environments clustered in a phylogenetically coherent subsurface clade, which also contains a number of Geobacter species isolated from subsurface environments. Concatamers constructed with 43 Geobacter genes amplified from these sites also clustered within this subsurface clade. 16S rRNA transcript and gene sequences in the sediments and groundwater at the Rifle site were highly similar, suggesting that sampling groundwater via monitoring wells can recover the most active Geobacter species. These results suggest that further study of Geobacter species in the subsurface clade is necessary to accurately model the behavior of Geobacter species during subsurface bioremediation of metal and organic contaminants.

Tracking snowmelt in the subsurface: time-lapse electrical resistivity imaging on an alpine hill slope.

Science.gov (United States)

Thayer, D.; Parsekian, A.; Hyde, K.; Beverly, D.; Speckman, H. N.; Ewers, B. E.

2015-12-01

In the mountain West region the winter snowpack provides more than 70% of our annual water supply. Modeling and predicting the timing and magnitude of snowmelt-driven water yield is difficult due to the complexities of hydrologic systems that move meltwater from snow to rivers. Particular challenges are understanding the temporal and spatial domain of subsurface hydraulic processes at relevant scales, which range from points to catchments. Subsurface characterization often requires borehole instrumentation, which is expensive and extremely difficult to install in remote, rugged terrain. Advancements in non-invasive geophysical methods allow us to monitor changes in geophysical parameters over time and infer changes in hydraulic processes. In the No-Name experimental catchment in the Medicine Bow National Forest in Wyoming, we are conducting a multi-season, time-lapse electrical resistivity imaging survey on a sub-alpine hill slope. This south-facing, partially forested slope ranges from 5 degrees to 35 degrees in steepness and consists of a soil mantle covering buried glacial talus deposits of unknown depth. A permanent grid of down-slope and cross-slope electrode arrays is monitored up to four times a day. The arrays span the entire vertical distance of the slope, from an exposed bedrock ridge to a seasonal drainage below, and cover treed and non-treed areas. Geophysical measurements are augmented by temperature and moisture time-series instrumented below the surface in a contiguous 3 meter borehole. A time-series of multiple resistivity models each day from May to July shows the changing distribution of subsurface moisture during a seasonal drying sequence punctuated by isolated rain events. Spatial patterns of changing moisture indicate that soil and gravel in the top two meters drain into a saturated layer parallel to the slope which overlies less saturated material. These results suggest that water from snowmelt and rain events tends to move down-slope beneath

Subsurface Contamination Control

Energy Technology Data Exchange (ETDEWEB)

Y. Yuan

2001-12-12

subsurface repository; (2) provides a table of derived LRCL for nuclides of radiological importance; (3) Provides an as low as is reasonably achievable (ALARA) evaluation of the derived LRCL by comparing potential onsite and offsite doses to documented ALARA requirements; (4) Provides a method for estimating potential releases from a defective WP; (5) Provides an evaluation of potential radioactive releases from a defective WP that may become airborne and result in contamination of the subsurface facility; and (6) Provides a preliminary analysis of the detectability of a potential WP leak to support the design of an airborne release monitoring system.

Design and construction of a French drain for groundwater diversion in solid waste storage area six at the Oak Ridge National Laboratory

International Nuclear Information System (INIS)

Davis, E.C.; Stansfield, R.G.

1984-05-01

Engineering modifiations or engineered barriers have been suggested as a possible means of improving the performance of low-level waste disposal sites located in the humid eastern United States. Design and construction of a passive French drain, located in Solid Waste Storage Area No. 6 at the Oak Ridge National Laboratory. The drain was designed to hydrologically isolate a 0.44-ha area that contains a group of 49 low-level waste trenches by separating it from upgradient groundwater recharge areas. The 252-m drain (maximum depth = 9 m) that surrounds the group of trenches on the north and east sides was excavated, lined with filter fabric, backfilled with crushed stone, and covered with a 0.6 m layer of excavated material at an estimated cost of $153,000. Of the 17 days it took to complete the work, about 5 days were spent excavating sidewall slide material that fell into the drain during excavation. Photography of the drain wall revealed the contorted structure of the weathered shale, which was responsible for many of the slides. Monitoring wells placed at intervals on the drain centerline indicate that groundwater is draining from the surrounding Maryville Formation (Conasauga Group); flows at catch basin No. 2 ranged from a base flow of 4 to 7 L/min to a maximum of 35 L/min, recorded on October 13. In response to groundwater flow in the drain, water levels in several monitoring wells adjacent to the drain have dropped by as much as 2.24 m to an elevation only slightly higher than the bottom of the French drain. In addition to the general lowering of the water table in the vicinity of the drain, water levels in three trenches began to subside, indicating that the drain is beginning to have an effect on the water in the trenches as well. Further monitoring of both drain discharge and water levels in monitoring wells across the site is continuing

Effect of subsurface drainage on salt movement and distribution in salt-affected soils

International Nuclear Information System (INIS)

Moustafa, A.T.A.; Seliem, M.H.; Bakhati, H.K.

1983-01-01

This study was carried out to evaluate different subsurface drainage treatments (combinations of depth and spacing) on salt movement and distribution. The soil is clay and the drainage was designed according to the steady-state condition (Hooghoudt's equation). Three spacings and two depths resulted in six drainage treatments. Soil samples represented the initial state of every treatment and after 14 months they (cotton followed by wheat) were analysed. The data show that drain depth has its effective role in salt leaching, while drain spacing has its effect on salt distribution in the soil profile. The leaching rate of each specific ion is also affected by the different drainage treatments. In general, the salt movement and distribution should be taken into consideration when evaluating the design of drainage systems. (author)

SUBSURFACE VISUAL ALARM SYSTEM ANALYSIS

International Nuclear Information System (INIS)

D.W. Markman

2001-01-01

The ''Subsurface Fire Hazard Analysis'' (CRWMS M andO 1998, page 61), and the document, ''Title III Evaluation Report for the Surface and Subsurface Communication System'', (CRWMS M andO 1999a, pages 21 and 23), both indicate the installed communication system is adequate to support Exploratory Studies Facility (ESF) activities with the exception of the mine phone system for emergency notification purposes. They recommend the installation of a visual alarm system to supplement the page/party phone system The purpose of this analysis is to identify data communication highway design approaches, and provide justification for the selected or recommended alternatives for the data communication of the subsurface visual alarm system. This analysis is being prepared to document a basis for the design selection of the data communication method. This analysis will briefly describe existing data or voice communication or monitoring systems within the ESF, and look at how these may be revised or adapted to support the needed data highway of the subsurface visual alarm. system. The existing PLC communication system installed in subsurface is providing data communication for alcove No.5 ventilation fans, south portal ventilation fans, bulkhead doors and generator monitoring system. It is given that the data communication of the subsurface visual alarm system will be a digital based system. It is also given that it is most feasible to take advantage of existing systems and equipment and not consider an entirely new data communication system design and installation. The scope and primary objectives of this analysis are to: (1) Briefly review and describe existing available data communication highways or systems within the ESF. (2) Examine technical characteristics of an existing system to disqualify a design alternative is paramount in minimizing the number of and depth of a system review. (3) Apply general engineering design practices or criteria such as relative cost, and degree

Surface and subsurface continuous gravimetric monitoring of groundwater recharge processes through the karst vadose zone at Rochefort Cave (Belgium)

Science.gov (United States)

Watlet, A.; Van Camp, M. J.; Francis, O.; Poulain, A.; Hallet, V.; Triantafyllou, A.; Delforge, D.; Quinif, Y.; Van Ruymbeke, M.; Kaufmann, O.

2017-12-01

Ground-based gravimetry is a non-invasive and integrated tool to characterize hydrological processes in complex environments such as karsts or volcanoes. A problem in ground-based gravity measurements however concerns the lack of sensitivity in the first meters below the topographical surface, added to limited infiltration below the gravimeter building (umbrella effect). Such limitations disappear when measuring underground. Coupling surface and subsurface gravity measurements therefore allow isolating hydrological signals occurring in the zone between the two gravimeters. We present a coupled surface/subsurface continuous gravimetric monitoring of 2 years at the Rochefort Cave Laboratory (Belgium). The gravity record includes surface measurements of a GWR superconducting gravimeter and subsurface measurements of a Micro-g LaCoste gPhone gravimeter, installed in a cave 35 m below the surface station. The recharge of karstic aquifers is extremely complex to model, mostly because karst hydrological systems are composed of strongly heterogeneous flows. Most of the problem comes from the inadequacy of conventional measuring tools to correctly sample such heterogeneous media, and particularly the existence of a duality of flow types infiltrating the vadose zone: from rapid flows via open conduits to slow seepage through porous matrix. Using the surface/subsurface gravity difference, we were able to identify a significant seasonal groundwater recharge within the karst vadose zone. Seasonal or perennial perched reservoirs have already been proven to exist in several karst areas due to the heterogeneity of the porosity and permeability gradient in karstified carbonated rocks. Our gravimetric experiment allows assessing more precisely the recharge processes of such reservoirs. The gravity variations were also compared with surface and in-cave hydrogeological monitoring (i.e. soil moisture, in-cave percolating water discharges, water levels of the saturated zone). Combined

Monitoring subsurface coal fires in Jharia coalfield using ...

Indian Academy of Sciences (India)

ing adverse effects on the regional environment ... subsurface coal fires and to study its lateral prop- ... as is the case with the recently developed Persis- .... using Statistical-Cost, Network-Flow Algorithm ..... dence of Kolkata (Calcutta) City, India during the 1990s ... a case study in the east of France; Int. J. Remote Sens.

Sub-Surface Oil Monitoring Cruise (GU1002, EK60)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Objectives were to evaluate ability of acoustic echosounder measurements to detect and localize a sub-surface plume of oil or related hydrocarbons released from the...

Monitoring and Quantifying Subsurface Ice and Water Content in Permafrost Regions Based on Geophysical Data Sets

Science.gov (United States)

Hauck, C.; Bach, M.; Hilbich, C.

2007-12-01

Based on recent observational evidence of climate change in permafrost regions, it is now recognised that a detailed knowledge of the material composition of the subsurface in permafrost regions is required for modelling of the future evolution of the ground thermal regime and an assessment of the hazard potential due to degrading permafrost. However, due to the remote location of permafrost areas and the corresponding difficulties in obtaining high-quality data sets of the subsurface, knowledge about the material composition in permafrost areas is scarce. In frozen ground subsurface material may consist of four different phases: rock/soil matrix, unfrozen pore water, ice and air-filled pore space. Applications of geophysical techniques for determining the subsurface composition are comparatively cheap and logistically feasible alternatives to the single point information from boreholes. Due to the complexity of the subsurface a combination of complementary geophysical methods (e.g. electrical resistivity tomography (ERT) and refraction seismic tomography) is often favoured to avoid ambiguities in the interpretation of the results. The indirect nature of geophysical soundings requires a relation between the measured variable (electrical resistivity, seismic velocity) and the rock-, water-, ice- and air content. In this contribution we will present a model which determines the volumetric fractions of these four phases from tomographic electrical and seismic data sets. The so-called 4-phase model is based on two well-known geophysical mixing rules using observed resistivity and velocity data as input data on a 2-dimensional grid. Material properties such as resistivity and P- wave velocity of the host rock material and the pore water have to be known beforehand. The remaining free model parameters can be determined by a Monte-Carlo approach, the results of which are used additionally as indicator for the reliability of the model results. First results confirm the

National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in American Samoa from 2012 to 2015

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

Using constructed wetlands to treat subsurface drainage from intensively grazed dairy pastures in New Zealand.

Science.gov (United States)

Tanner, C C; Nguyen, M Long; Sukias, J P S

2003-01-01

Performance data, during the start-up period, are presented for constructed wetlands treating subsurface drainage from dairy pastures in Waikato (rain-fed) and Northland (irrigated), North Island, New Zealand. The wetlands comprised an estimated 1 and 2% of the drained catchment areas, respectively. Nitrate concentrations were high in the drainage inflows at both sites (medians 10 g m(-3) at Waikato and 6.5 g m(-3) at Northland), but organic N was also an important form of N at Waikato (37% of TN). Comparison of wetland inflow and outflow nutrient concentrations showed overall nutrient reductions during passage through the wetlands for NO3-N (34 and 94% for medians, respectively), TN (56 and 33%, respectively), and DRP (80%, Northland only). Median NH4-N (both sites) and DRP (Waikato) concentrations showed apparent increases between the wetland inlets and outlets. However, a mass balance calculated for the 3 month preliminary monitoring periods showed substantial mass removal of DRP (80%) and all measured forms of N (NO3-N 78%, NH4-N 41%, Org-N 99.8% and TN 96%) in the Waikato wetland. Monitoring of these systems needs to be continued through a range of seasons and years to fully assess their long-term performance.

Subsurface event detection and classification using Wireless Signal Networks.

Science.gov (United States)

Yoon, Suk-Un; Ghazanfari, Ehsan; Cheng, Liang; Pamukcu, Sibel; Suleiman, Muhannad T

2012-11-05

Subsurface environment sensing and monitoring applications such as detection of water intrusion or a landslide, which could significantly change the physical properties of the host soil, can be accomplished using a novel concept, Wireless Signal Networks (WSiNs). The wireless signal networks take advantage of the variations of radio signal strength on the distributed underground sensor nodes of WSiNs to monitor and characterize the sensed area. To characterize subsurface environments for event detection and classification, this paper provides a detailed list and experimental data of soil properties on how radio propagation is affected by soil properties in subsurface communication environments. Experiments demonstrated that calibrated wireless signal strength variations can be used as indicators to sense changes in the subsurface environment. The concept of WSiNs for the subsurface event detection is evaluated with applications such as detection of water intrusion, relative density change, and relative motion using actual underground sensor nodes. To classify geo-events using the measured signal strength as a main indicator of geo-events, we propose a window-based minimum distance classifier based on Bayesian decision theory. The window-based classifier for wireless signal networks has two steps: event detection and event classification. With the event detection, the window-based classifier classifies geo-events on the event occurring regions that are called a classification window. The proposed window-based classification method is evaluated with a water leakage experiment in which the data has been measured in laboratory experiments. In these experiments, the proposed detection and classification method based on wireless signal network can detect and classify subsurface events.

Using NMR decay-time measurements to monitor and characterize DNAPL and moisture in subsurface porous media

International Nuclear Information System (INIS)

Timothy A. White; Russel C. Hertzog; Christian Straley

2007-01-01

Knowing how environmental properties affect dense nonaqueous phase liquid (DNAPL) solvent flow in the subsurface is essential for developing models of flow and transport in the vadose zone necessary for designing remediation and long-term stewardship strategies. For example, one must know if solvents are flowing in water-wetted or solvent-wetted environments, the pore-size distribution of the region containing DNAPLs, and the impact of contaminated plumes and their transport mechanisms in porous media. Our research investigates the capability and limitations of low-field proton nuclear magnetic resonance (NMR) relaxation decay-rate measurements for determining environmental properties affecting DNAPL solvent flow in the subsurface. The measurements that can be performed with the laboratory low-field system can also be performed in situ in the field with the current generation of commercial borehole logging tools. The oil and gas industry uses NMR measurements in deep subsurface, consolidated formations to determine porosity and hydrocarbon content and to estimate formation permeability. These determinations rely on the ability of NMR to distinguish between water and hydrocarbons in the pore space and to obtain the distribution of pore sizes from relaxation decay-rate distributions. In this paper we will show how NMR measurement techniques can be used to characterize, monitor, and evaluate the dynamics of mixed-fluids (water-DNAPL) in unconsolidated near-surface porous environments and describe the use of proton NMR T2 (spin-spin relaxation time) measurements in unconsolidated sandy-soil samples to identify and characterize the presence of DNAPLs in these environments. The potential of NMR decay-rate distributions for characterizing DNAPL fluids in the subsurface and understanding their flow mechanisms has not previously been exploited; however, near-surface unsaturated vadose zone environments do provide unique challenges for using NMR measurements. These

National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in the Hawaiian Archipelago from 2010 to 2016

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in the Marianas Archipelago from 2011 to 2014

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

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) ...

Lower-Temperature Subsurface Layout and Ventilation Concepts

International Nuclear Information System (INIS)

Christine L. Linden; Edward G. Thomas

2001-01-01

This analysis combines work scope identified as subsurface facility (SSF) low temperature (LT) Facilities System and SSF LT Ventilation System in the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M and O 2001b, pp. 6 and 7, and pp. 13 and 14). In accordance with this technical work plan (TWP), this analysis is performed using AP-3.10Q, Analyses and Models. It also incorporates the procedure AP-SI.1Q, Software Management. The purpose of this analysis is to develop an overall subsurface layout system and the overall ventilation system concepts that address a lower-temperature operating mode for the Monitored Geologic Repository (MGR). The objective of this analysis is to provide a technical design product that supports the lower-temperature operating mode concept for the revision of the system description documents and to provide a basis for the system description document design descriptions. The overall subsurface layout analysis develops and describes the overall subsurface layout, including performance confirmation facilities (also referred to as Test and Evaluation Facilities) for the Site Recommendation design. This analysis also incorporates current program directives for thermal management

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...

Subsurface Event Detection and Classification Using Wireless Signal Networks

Directory of Open Access Journals (Sweden)

Muhannad T. Suleiman

2012-11-01

Full Text Available Subsurface environment sensing and monitoring applications such as detection of water intrusion or a landslide, which could significantly change the physical properties of the host soil, can be accomplished using a novel concept, Wireless Signal Networks (WSiNs. The wireless signal networks take advantage of the variations of radio signal strength on the distributed underground sensor nodes of WSiNs to monitor and characterize the sensed area. To characterize subsurface environments for event detection and classification, this paper provides a detailed list and experimental data of soil properties on how radio propagation is affected by soil properties in subsurface communication environments. Experiments demonstrated that calibrated wireless signal strength variations can be used as indicators to sense changes in the subsurface environment. The concept of WSiNs for the subsurface event detection is evaluated with applications such as detection of water intrusion, relative density change, and relative motion using actual underground sensor nodes. To classify geo-events using the measured signal strength as a main indicator of geo-events, we propose a window-based minimum distance classifier based on Bayesian decision theory. The window-based classifier for wireless signal networks has two steps: event detection and event classification. With the event detection, the window-based classifier classifies geo-events on the event occurring regions that are called a classification window. The proposed window-based classification method is evaluated with a water leakage experiment in which the data has been measured in laboratory experiments. In these experiments, the proposed detection and classification method based on wireless signal network can detect and classify subsurface events.

Monitoring the Vadose Zone Moisture Regime Below a Surface Barrier

Science.gov (United States)

Zhang, Z. F.; Strickland, C. E.; Field, J. G.

2009-12-01

A 6000 m2 interim surface barrier has been constructed over a portion of the T Tank Farm in the Depart of Energy’s Hanford site. The purpose of using a surface barrier was to reduce or eliminate the infiltration of meteoric precipitation into the contaminated soil zone due to past leaks from Tank T-106 and hence to reduce the rate of movement of the plume. As part of the demonstration effort, vadose zone moisture is being monitored to assess the effectiveness of the barrier on the reduction of soil moisture flow. A vadose zone monitoring system was installed to measure soil water conditions at four horizontal locations (i.e., instrument Nests A, B, C, and D) outside, near the edge of, and beneath the barrier. Each instrument nest consists of a capacitance probe with multiple sensors, multiple heat-dissipation units, and a neutron probe access tube used to measure soil-water content and soil-water pressure. Nest A serves as a control by providing subsurface conditions outside the influence of the surface barrier. Nest B provides subsurface measurements to assess barrier edge effects. Nests C and D are used to assess the impact of the surface barrier on soil-moisture conditions beneath it. Monitoring began in September 2006 and continues to the present. To date, the monitoring system has provided high-quality data. Results show that the soil beneath the barrier has been draining from the shallower depth. The lack of climate-caused seasonal variation of soil water condition beneath the barrier indicates that the surface barrier has minimized water exchange between the soil and the atmosphere.

Estimating Impacts of Agricultural Subsurface Drainage on Evapotranspiration Using the Landsat Imagery-Based METRIC Model

Directory of Open Access Journals (Sweden)

Kul Khand

2017-11-01

Full Text Available Agricultural subsurface drainage changes the field hydrology and potentially the amount of water available to the crop by altering the flow path and the rate and timing of water removal. Evapotranspiration (ET is normally among the largest components of the field water budget, and the changes in ET from the introduction of subsurface drainage are likely to have a greater influence on the overall water yield (surface runoff plus subsurface drainage from subsurface drained (TD fields compared to fields without subsurface drainage (UD. To test this hypothesis, we examined the impact of subsurface drainage on ET at two sites located in the Upper Midwest (North Dakota-Site 1 and South Dakota-Site 2 using the Landsat imagery-based METRIC (Mapping Evapotranspiration at high Resolution with Internalized Calibration model. Site 1 was planted with corn (Zea mays L. and soybean (Glycine max L. during the 2009 and 2010 growing seasons, respectively. Site 2 was planted with corn for the 2013 growing season. During the corn growing seasons (2009 and 2013, differences between the total ET from TD and UD fields were less than 5 mm. For the soybean year (2010, ET from the UD field was 10% (53 mm greater than that from the TD field. During the peak ET period from June to September for all study years, ET differences from TD and UD fields were within 15 mm (<3%. Overall, differences between daily ET from TD and UD fields were not statistically significant (p > 0.05 and showed no consistent relationship.

Time-Lapse Electrical Resistivity Investigations for Imaging the Grouting Injection in Shallow Subsurface Cavities

Directory of Open Access Journals (Sweden)

Muhammad Farooq

2014-01-01

Full Text Available The highway of Yongweol-ri, Muan-gun, south-western part of the South Korean Peninsula, is underlain by the abandoned of subsurface cavities, which were discovered in 2005. These cavities lie at shallow depths with the range of 5∼15 meters below the ground surface. Numerous subsidence events have repeatedly occurred in the past few years, damaging infrastructure and highway. As a result of continuing subsidence issues, the Korean Institute of Geosciences and Mineral Resources (KIGAM was requested by local administration to resolve the issue. The KIGAM used geophysical methods to delineate subsurface cavities and improve more refined understanding of the cavities network in the study area. Cement based grouting has been widely employed in the construction industry to reinforce subsurface ground. In this research work, time-lapse electrical resistivity surveys were accomplished to monitor the grouting injection in the subsurface cavities beneath the highway, which have provided a quasi-real-time monitoring for modifying the subsurface cavities related to ground reinforcement, which would be difficult with direct methods. The results obtained from time-lapse electrical resistivity technique have satisfactory imaged the grouting injection experiment in the subsurface cavities beneath the highway. Furthermore, the borehole camera confirmed the presence of grouting material in the subsurface cavities, and hence this procedure increases the mechanical resistance of subsurface cavities below the highway.

Drilling Automation Demonstrations in Subsurface Exploration for Astrobiology

Science.gov (United States)

Glass, Brian; Cannon, H.; Lee, P.; Hanagud, S.; Davis, K.

2006-01-01

This project proposes to study subsurface permafrost microbial habitats at a relevant Arctic Mars-analog site (Haughton Crater, Devon Island, Canada) while developing and maturing the subsurface drilling and drilling automation technologies that will be required by post-2010 missions. It builds on earlier drilling technology projects to add permafrost and ice-drilling capabilities to 5m with a lightweight drill that will be automatically monitored and controlled in-situ. Frozen cores obtained with this drill under sterilized protocols will be used in testing three hypotheses pertaining to near-surface physical geology and ground H2O ice distribution, viewed as a habitat for microbial life in subsurface ice and ice-consolidated sediments. Automation technologies employed will demonstrate hands-off diagnostics and drill control, using novel vibrational dynamical analysis methods and model-based reasoning to monitor and identify drilling fault states before and during faults. Three field deployments, to a Mars-analog site with frozen impact crater fallback breccia, will support science goals, provide a rigorous test of drilling automation and lightweight permafrost drilling, and leverage past experience with the field site s particular logistics.

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.

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

National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in the Pacific Remote Island Areas from 2011 to 2016

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

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

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

Study of the development of high resolution sub-surface fluid monitoring system using Accurately Controlled Routine Operated Seismic Sources (ACROSS); Seimitsu seigyo shingen ni yoru chika ryutai koseido monitoring no kenkyu

Energy Technology Data Exchange (ETDEWEB)

Kumazawa, M; Ogawa, K; Fujii, N; Yamaoka, K; Kumagai, H; Takei, Y [Nagoya University, Nagoya (Japan). Faculty of Science; Ishihara, K; Nakaya, m [New Energy and Industrial Technology Development Organization, Tokyo, (Japan)

1997-02-01

Fourier seismology capable of determining quantities related to elastic wave velocity dispersibility and non-elastic damping is under development, and studies are under way for the development of a sub-surface probing technology utilizing this seismology. It is deemed that the above-said quantities are related to the occurrence of earthquakes, behavior of sub-surface water, and migration of magma. In this method, precisely controlled sinusoidal waves are radiated and the received spectral data is subjected to cepstrum analysis, advantageous over other methods in that it achieves a high S/N ratio in a non-destructive way, facilitates deep structure analysis, and capable of monitoring changes with the elapse of time in such a structure. A newly-developed high-mobility transportable quake generator is described, which covers a wider frequency range and aims at the short-distance exploration of sub-surface conditions. Important components of the quake generator include an eccentric mass bearing capable of dealing with high-speed rotation enabling high frequency oscillation, variable mechanism for the primary moment of inertia, exciter and ground surface coupler allowing operations on a soft ground, and torque cancelling mechanism for the excitation of SH waves only. 3 figs.

High-frequency monitoring of water fluxes and nutrient loads to assess the effects of controlled drainage on water storage and nutrient transport

Science.gov (United States)

Rozemeijer, J. C.; Visser, A.; Borren, W.; Winegram, M.; van der Velde, Y.; Klein, J.; Broers, H. P.

2016-01-01

High nitrogen (N) and phosphorus (P) fluxes from upstream agriculture threaten aquatic ecosystems in surface waters and estuaries, especially in areas characterized by high agricultural N and P inputs and densely drained catchments like the Netherlands. Controlled drainage has been recognized as an effective option to optimize soil moisture conditions for agriculture and to reduce unnecessary losses of fresh water and nutrients. This is achieved by introducing control structures with adjustable overflow levels into subsurface tube drain systems. A small-scale (1 ha) field experiment was designed to investigate the hydrological and chemical changes after introducing controlled drainage. Precipitation rates and the response of water tables and drain fluxes were measured in the periods before the introduction of controlled drainage (2007-2008) and after (2009-2011). For the N and P concentration measurements, auto-analyzers for continuous records were combined with passive samplers for time-averaged concentrations at individual drain outlets. The experimental setup enabled the quantification of changes in the water and solute balance after introducing controlled drainage. The results showed that introducing controlled drainage reduced the drain discharge and increased the groundwater storage in the field. To achieve this, the overflow levels have to be elevated in early spring, before the drain discharge stops due to dryer conditions and falling groundwater levels. The groundwater storage in the field would have been larger if the water levels in the adjacent ditch were controlled as well by an adjustable weir. The N concentrations and loads increased, which was largely related to elevated concentrations in one of the three monitored tube drains. The P loads via the tube drains reduced due to the reduction in discharge after introducing controlled drainage. However, this may be counteracted by the higher groundwater levels and the larger contribution of N- and P

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.

Coupled Monitoring and Inverse Modeling to Investigate Surface - Subsurface Hydrological and Thermal Dynamics in the Arctic Tundra

Science.gov (United States)

Tran, A. P.; Dafflon, B.; Hubbard, S. S.; Bisht, G.; Peterson, J.; Ulrich, C.; Romanovsky, V. E.; Kneafsey, T. J.; Wu, Y.

2015-12-01

Quantitative characterization of the soil surface-subsurface hydrological and thermal processes is essential as they are primary factors that control the biogeochemical processes, ecological landscapes and greenhouse gas fluxes. In the Artic region, the surface-subsurface hydrological and thermal regimes co-interact and are both largely influenced by soil texture and soil organic content. In this study, we present a coupled inversion scheme that jointly inverts hydrological, thermal and geophysical data to estimate the vertical profiles of clay, sand and organic contents. Within this inversion scheme, the Community Land Model (CLM4.5) serves as a forward model to simulate the land-surface energy balance and subsurface hydrological-thermal processes. Soil electrical conductivity (from electrical resistivity tomography), temperature and water content are linked together via petrophysical and geophysical models. Particularly, the inversion scheme accounts for the influences of the soil organic and mineral content on both of the hydrological-thermal dynamics and the petrophysical relationship. We applied the inversion scheme to the Next Generation Ecosystem Experiments (NGEE) intensive site in Barrow, AK, which is characterized by polygonal-shaped arctic tundra. The monitoring system autonomously provides a suite of above-ground measurements (e.g., precipitation, air temperature, wind speed, short-long wave radiation, canopy greenness and eddy covariance) as well as below-ground measurements (soil moisture, soil temperature, thaw layer thickness, snow thickness and soil electrical conductivity), which complement other periodic, manually collected measurements. The preliminary results indicate that the model can well reproduce the spatiotemporal dynamics of the soil temperature, and therefore, accurately predict the active layer thickness. The hydrological and thermal dynamics are closely linked to the polygon types and polygon features. The results also enable the

Considerations in the development of subsurface containment barrier performance standards

International Nuclear Information System (INIS)

Dunstan, S.; Zdinak, A.P.; Lodman, D.

1997-01-01

The U.S. Department of Energy (DOE) is supporting subsurface barriers as an alternative remedial option for management of contamination problems at their facilities. Past cleanup initiatives have sometimes proven ineffective or extremely expensive. Economic considerations coupled with changing public and regulatory philosophies regarding remediation techniques makes subsurface barriers a promising technology for future cleanup efforts. As part of the initiative to develop subsurface containment barriers as an alternative remedial option, DOE funded MSE Technology Applications, Inc. (MSE) to conduct a comprehensive review to identify performance considerations for the acceptability of subsurface barrier technologies as a containment method. Findings from this evaluation were intended to provide a basis for selection and application of containment technologies to address waste problems at DOE sites. Based on this study, the development of performance standards should consider: (1) sustainable low hydraulic conductivity; (2) capability to meet applicable regulations; (3) compatibility with subsurface environmental conditions; (4) durability and long-term stability; (5) repairability; and (6) verification and monitoring. This paper describes the approach for determining considerations for performance standards

Pacific Reef Assessment and Monitoring Program: Subsurface Temperature Recorders (STRs) at selected coral reef locations across the Pacific Ocean from 2001-09-20 to 2012-09-28 (NCEI Accession 0162471)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

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.

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.

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.

Detecting Subsurface Agricultural Tile Drainage using GIS and Remote Sensing Technique

Science.gov (United States)

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

2015-12-01

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

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

Directory of Open Access Journals (Sweden)

B. Zhang

2011-10-01

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

Quantifying Subsurface Water and Heat Distribution and its Linkage with Landscape Properties in Terrestrial Environment using Hydro-Thermal-Geophysical Monitoring and Coupled Inverse Modeling

Science.gov (United States)

Dafflon, B.; Tran, A. P.; Wainwright, H. M.; Hubbard, S. S.; Peterson, J.; Ulrich, C.; Williams, K. H.

2015-12-01

Quantifying water and heat fluxes in the subsurface is crucial for managing water resources and for understanding the terrestrial ecosystem where hydrological properties drive a variety of biogeochemical processes across a large range of spatial and temporal scales. Here, we present the development of an advanced monitoring strategy where hydro-thermal-geophysical datasets are continuously acquired and further involved in a novel inverse modeling framework to estimate the hydraulic and thermal parameter that control heat and water dynamics in the subsurface and further influence surface processes such as evapotranspiration and vegetation growth. The measured and estimated soil properties are also used to investigate co-interaction between subsurface and surface dynamics by using above-ground aerial imaging. The value of this approach is demonstrated at two different sites, one in the polygonal shaped Arctic tundra where water and heat dynamics have a strong impact on freeze-thaw processes, vegetation and biogeochemical processes, and one in a floodplain along the Colorado River where hydrological fluxes between compartments of the system (surface, vadose zone and groundwater) drive biogeochemical transformations. Results show that the developed strategy using geophysical, point-scale and aerial measurements is successful to delineate the spatial distribution of hydrostratigraphic units having distinct physicochemical properties, to monitor and quantify in high resolution water and heat distribution and its linkage with vegetation, geomorphology and weather conditions, and to estimate hydraulic and thermal parameters for enhanced predictions of water and heat fluxes as well as evapotranspiration. Further, in the Colorado floodplain, results document the potential presence of only periodic infiltration pulses as a key hot moment controlling soil hydro and biogeochemical functioning. In the arctic, results show the strong linkage between soil water content, thermal

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.

LIBS Sensor for Sub-surface CO2 Leak Detection in Carbon Sequestration

Directory of Open Access Journals (Sweden)

Jinesh JAIN

2017-07-01

Full Text Available Monitoring carbon sequestration poses numerous challenges to the sensor community. For example, the subsurface environment is notoriously harsh, with large potential mechanical, thermal, and chemical stresses, making long-term stability and survival a challenge to any potential in situ monitoring method. Laser induced breakdown spectroscopy (LIBS has been demonstrated as a promising technology for chemical monitoring of harsh environments and hard to reach places. LIBS has a real- time monitoring capability and can be used for the elemental and isotopic analysis of solid, liquid, and gas samples. The flexibility of the probe design and the use of fiber- optics has made LIBS particularly suited for remote measurements. The paper focuses on developing a LIBS instrument for downhole high-pressure, high-temperature brine experiments, where CO2 leakage could result in changes in the trace mineral composition of an aquifer. The progress in fabricating a compact, robust, and simple LIBS sensor for widespread subsurface leak detection is presented.

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.

Potential for Nitrogen Fixation and Nitrification in the Granite-Hosted Subsurface at Henderson Mine, CO

Science.gov (United States)

Swanner, Elizabeth D.; Templeton, Alexis S.

2011-01-01

The existence of life in the deep terrestrial subsurface is established, yet few studies have investigated the origin of nitrogen that supports deep life. Previously, 16S rRNA gene surveys cataloged a diverse microbial community in subsurface fluids draining from boreholes 3000 feet deep at Henderson Mine, CO, USA (Sahl et al., 2008). The prior characterization of the fluid chemistry and microbial community forms the basis for the further investigation here of the source of NH4+. The reported fluid chemistry included N2, NH4+ (5–112 μM), NO2− (27–48 μM), and NO3− (17–72 μM). In this study, the correlation between low NH4+ concentrations in dominantly meteoric fluids and higher NH4+ in rock-reacted fluids is used to hypothesize that NH4+ is sourced from NH4+-bearing biotite. However, biotite samples from the host rocks and ore-body minerals were analyzed by Fourier transform infrared (FTIR) microscopy and none-contained NH4+. However, the nitrogenase-encoding gene nifH was successfully amplified from DNA of the fluid sample with high NH4+, suggesting that subsurface microbes have the capability to fix N2. If so, unregulated nitrogen fixation may account for the relatively high NH4+ concentrations in the fluids. Additionally, the amoA and nxrB genes for archaeal ammonium monooxygenase and nitrite oxidoreductase, respectively, were amplified from the high NH4+ fluid DNA, while bacterial amoA genes were not. Putative nitrifying organisms are closely related to ammonium-oxidizing Crenarchaeota and nitrite-oxidizing Nitrospira detected in other subsurface sites based upon 16S rRNA sequence analysis. Thermodynamic calculations underscore the importance of NH4+ as an energy source in a subsurface nitrification pathway. These results suggest that the subsurface microbial community at Henderson is adapted to the low nutrient and energy environment by their capability of fixing nitrogen, and that fixed nitrogen may support subsurface biomass via

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.

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...

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)

Evaluation of the Dutch subsurface geoportal: What lies beneath?

NARCIS (Netherlands)

Lance, K.T.; Georgiadou, Y.; Bregt, A.K.

2011-01-01

This paper focuses on a geoportal from a “what lies beneath” perspective. It analyses processes of budgeting, planning, monitoring, performance measurement, and reporting of the national initiative titled Digital Information of the Dutch Subsurface (known by its Dutch acronym, DINO). The study is

Electrical Resistance Tomography for Subsurface Imaging. Innovative Technology Summary Report

International Nuclear Information System (INIS)

None

2000-01-01

Electrical Resistance Tomography (ERT) noninvasively maps the 3-D resistivity field in the subsurface. It can be used on a scale from feet to kilometers. The 3-D resistivity field can be used to infer subsurface hydrogeological features and provides good resolution mapping of confining layers of various types. ERT imaging has been used for real-time monitoring and process control of remediation processes such as soil heating, pump and treat, steam injection, electrokinetics, Dynamic Underground Stripping (TechID 7), Hydrous Pyrolysis/Oxidation (TechID 1519) and more. ERT can be deployed via rapid and inexpensive installation of electrodes using a Cone Penetrometer (TechID 243). Additional applications are described under TechID 140 (Tanks) and TechID 2120 (Injected Subsurface Barriers); see also the related technology TechID 2121 (EIT)

National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in American Samoa from 2012-04-08 to 2013-04-03 (NCEI Accession 0162220)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in American Samoa from 2012-03-21 to 2015-03-25 (NCEI Accession 0162246)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

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 .

A technical investigation on tools and concepts for sustainable management of the subsurface in The Netherlands.

Science.gov (United States)

Griffioen, Jasper; van Wensem, Joke; Oomes, Justine L M; Barends, Frans; Breunese, Jaap; Bruining, Hans; Olsthoorn, Theo; Stams, Alfons J M; van der Stoel, Almer E C

2014-07-01

In response to increasing use of the subsurface, there is a need to modernise policies on sustainable use of the subsurface. This holds in particular for the densely populated Netherlands. We aimed to analyse current practice of subsurface management and the associated pressure points and to establish a conceptual overview of the technical issues related to sustainable management of the subsurface. Case studies on the exploitation of subsurface resources (including spatial use of the subsurface) were analysed, examining social relevance, environmental impact, pressure points and management solutions. The case studies ranged from constructing underground garages to geothermal exploitation. The following issues were identified for the technological/scientific aspects: site investigation, suitability, risk assessment, monitoring and measures in the event of failure. Additionally, the following general issues were identified for the administrative aspects: spatial planning, option assessment, precaution, transparency, responsibility and liability. These issues were explored on their technological implications within the framework of sustainable management of the subsurface. This resulted into the following key aspects: (1) sustainability assessment, (2) dealing with uncertainty and (3) policy instruments and governance. For all three aspects, different options were identified which might have a legal, economic or ethical background. The technological implications of these backgrounds have been identified. A set of recommendations for sustainable management of the subsurface resources (incl. space) was established: (1) management should be driven by scarcity, (2) always implement closed loop monitoring when the subsurface activities are high-risk, (3) when dealing with unknown features and heterogeneity, apply the precautionary principle, (4) responsibility and liability for damage must be set out in legislation and (5) sustainability should be incorporated in all

Assessment of the use of selected chemical and microbiological constituents as indicators of wastewater in curtain drains from home sewage-treatment systems in Medina County, Ohio

Science.gov (United States)

Dumouchelle, Denise H.

2006-01-01

Many home sewage-treatment systems (HSTS) in Ohio use curtain or perimeter drains to depress the level of the subsurface water in and around the systems. These drains could possibly intercept partially untreated wastewater and release potential pathogens to ground-water and surface-water bodies. The quality of water in curtain drains from two different HSTS designs in Medina County, Ohio, was investigated using several methods. Six evaporation-transpiration-absorption (ETA) and five leach-line (LL) systems were investigated by determining nutrient concentrations, chloride/bromide ratios (Cl/Br), Escherichia coli (E. coli ) concentrations, coliphage genotyping, and genetic fingerprinting of E. coli. Water samples were collected at 11 sites and included samples from curtain drains, septic tanks, and residential water wells. Nitrate concentrations in the curtain drains ranged from 0.03 to 3.53 mg/L (milligrams per liter), as N. Concentrations of chloride in 10 of the 11 curtain drains ranged from 5.5 to 21 mg/L; the chloride concentration in the eleventh curtain drain was 340 mg/L. Bromide concentrations in 11 curtain drains ranged from 0.01 to 0.22 mg/L. Cl/Br ratios ranged from 86 to 2,000. F-specific coliphage were not found in any curtain-drain samples. Concentrations of E. coli in the curtain drains ranged from 1 to 760 colonies per 100 milliliters. The curtain-drain water-quality data were evaluated to determine whether HSTS-derived water was present in the curtain drains. Nutrient concentrations were too low to be of use in the determination. The Cl/Br ratios appear promising. Coliphage was not detected in the curtain drains, so genotyping could not be attempted. E. coli concentrations in the curtain drains were all less than those from the corresponding HSTS; only one sample exceeded the Ohio secondary-contact water-quality standard. The genetic fingerprinting data were inconclusive because multiple links between unrelated sites were found. Although the

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

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.

Subsurface structure and physical properties; interim report for fiscal 2001 on frontiers in monitoring science and technology for earthquake environments

International Nuclear Information System (INIS)

2000-08-01

This report includes a final comment made and released by the advisory committee set up for fiscal 2001 by Japan Nuclear Cycle Development Institute (JNC) for inquiry into research progress in subsurface structure and physical properties at Tono Geoscience Center. The appendices contain the membership of the committee, the investigation procedure of the committee, the research subjects and objectives, the experimental results obtained and data included in the interim report including earthquake prediction study and its application for rock mechanics, geochemical and hydrological measurements and monitoring groundwater behaviors, and other materials submitted at the committee for the investigation. (S. Ohno)

Concept of subsurface micro-sensing; Chika joho no micro sensing

Energy Technology Data Exchange (ETDEWEB)

Niitsuma, H [Tohoku University, Sendai (Japan). Faculty of Engineering

1997-05-27

This paper describes concept of subsurface micro-sensing. It is intended to achieve an epoch-making development of subsurface engineerings by developing such technologies as micro measurement of well interior, micro measurement while drilling (MWD), and micro intelligent logging. These technologies are supported by development of micro sensors and micro drilling techniques using micro machine technologies. Micronizing the subsurface sensors makes mass production of sensors with equivalent performance possible, and the production cost can be reduced largely. The sensors can be embedded or used disposably, resulting in increased mobility in measurement and higher performance. Installing multiple number of sensors makes high-accuracy measurement possible, such as array measurement. The sensors can be linked easily with photo-electronics components, realizing remote measurement at low price and high accuracy. Control in micro-drilling and MWD also become possible. Such advantages may also be expected as installing the sensors on the outer side of wells in use and monitoring subsurface information during production. Expectation on them is large as a new paradigm of underground exploration and measurement. 1 fig.

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.

National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in the Marianas Archipelago from 2011-04-09 to 2014-05-06 (NCEI Accession 0162244)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

National Coral Reef Monitoring Program: Water Temperature Data from Subsurface Temperature Recorders (STRs) deployed at coral reef sites in the Hawaiian Archipelago from 2013-07-13 to 2016-09-28 (NCEI Accession 0162216)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water temperature data are collected using subsurface temperature recorders (STRs) that aid in the monitoring of seawater temperature variability at permanent coral...

Soil Carbon Dioxide Production and Surface Fluxes: Subsurface Physical Controls

Science.gov (United States)

Risk, D.; Kellman, L.; Beltrami, H.

Soil respiration is a critical determinant of landscape carbon balance. Variations in soil temperature and moisture patterns are important physical processes controlling soil respiration which need to be better understood. Relationships between soil respi- ration and physical controls are typically addressed using only surface flux data but other methods also exist which permit more rigorous interpretation of soil respira- tion processes. Here we use a combination of subsurface CO_{2} concentrations, surface CO_{2} fluxes and detailed physical monitoring of the subsurface envi- ronment to examine physical controls on soil CO_{2} production at four climate observatories in Eastern Canada. Results indicate that subsurface CO_{2} produc- tion is more strongly correlated to the subsurface thermal environment than the surface CO_{2} flux. Soil moisture was also found to have an important influence on sub- surface CO_{2} production, particularly in relation to the soil moisture - soil profile diffusivity relationship. Non-diffusive profile CO_{2} transport appears to be im- portant at these sites, resulting in a de-coupling of summertime surface fluxes from subsurface processes and violating assumptions that surface CO_{2} emissions are the result solely of diffusion. These results have implications for the study of soil respiration across a broad range of terrestrial environments.

Farmer driven national monitoring of nitrogen concentrations in drainage water in Denmark

Science.gov (United States)

Piil, Kristoffer; Lemming, Camilla; Kolind Hvid, Søren; Knudsen, Leif

2014-05-01

Field drains are often considered to short circuit the hydrological cycle in agricultural catchments and lead to an increased risk of nitrogen loss to the environment. Because of increased regulation of agricultural practices due to catchment management plans, resulting from the implementation of the water frame directive, Danish farmers pushed for a large scale monitoring of nitrogen loss from field drains. Therefore, the knowledge centre for agriculture, Denmark, organized a three year campaign where farmers and local agricultural advisory centres collected water samples from field drains three to five times during the winter season. Samples were analysed for nitrate and total nitrogen. Combined, more than 600 drains were monitored over the three years. During the first two years of monitoring, average winter concentrations of total nitrogen ranged from 0.1 mg N L-1 to 31.1 mg N L-1, and the fraction of total nitrogen present as nitrate ranged from 0% to 100%. This variation is much larger than what is observed in the Danish national monitoring and assessment programme, which monitors only a few drains in selected catchments. Statistical analysis revealed that drainage water nitrogen concentrations were significantly correlated to the cropping system and the landscape type (high ground/lowlands/raised seabed) in which the monitored fields were situated. The average total nitrogen concentration was more than 2 mg N L-1 lower on raised seabed than on high ground, and the average fraction of total nitrogen present as nitrate was more than 20% lower. This indicates that substantial nitrate reduction occurs at or above the drain depth on raised sea flats, in particular in the north of Denmark. This inherent nitrogen retention on raised seabed is not taken into account in the current environmental regulation, nor in the first generation catchment management plans. The monitoring program demonstrated large variation in nitrogen concentrations in drainage water, in

Scenario simulation based assessment of subsurface energy storage

Science.gov (United States)

Beyer, C.; Bauer, S.; Dahmke, A.

2014-12-01

-processes, mutual effects and influences on protected entities. The scenario analyses allow the deduction of monitoring concepts as well as a first methodology for large scale spatial planning of the geological subsurface. This concept is illustrated for different storage options and their impacts in space and time.

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.

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.

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.

FY1995 study of the development of high resolution sub-surface fluid monitoring system using accurately controlled routine operated seismic system; 1995 nendo seimitsu seigyo shingen ni yoru chika ryutai koseido monitoring no kenkyu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The development of new seismic sounding system based on the new concept of ACROSS (Accurately Controlled Routine-Operated Signal System) are aimed. The system includes not only new seismic sources but also the analyzing software specialize for the monitoring of the change in subsurface velocity structure, especially in the area of fluid resources. Powerful sources with good portability are strongly required for the practical data acquisition. Portable ACROSS sources (HIT) are developed. The system is mainly used to obtain the high resolution structure with relatively short penetration distance. The principal specifications are as follows: (1) 100Hz in maximum. (2) Linearly oscillating single force. This is generated by the combined two rotator moving opposite directions. (3) Variable force with little work. (4) Very simple source-ground coupler just put even on the soft ground. The system was operated at Yamagawa geothermal plant for two months. The result of the experiments are: (1) We confirmed the stability of the source over wide frequency range up to 100Hz. (2) We confirmed that amplitude and phase of ACROSS signal can be obtained very precisely. (3) Very small change of signal which arise from subsurface velocity change are detected. This indicates that the system can detect the slight velocity change due to variation of subsurface fluid system. (NEDO)

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.)

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.

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

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.

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...

Subsurface multidisciplinary research results at ICTJA-CSIC downhole lab and test site

Science.gov (United States)

Jurado, Maria Jose; Crespo, Jose; Salvany, Josep Maria; Teixidó, Teresa

2017-04-01

Two scientific boreholes, Almera-1 and Almera-2 were drilled in the Barcelona University campus area in 2011. The main purpose for this drilling was to create a new geophysical logging and downhole monitoring research facility and infrastructure. We present results obtained in the frame of multidisciplinary studies and experiments carried out since 2011 at the ICTJA "Borehole Geophysical Logging Lab - Scientific Boreholes Almera" downhole lab facilities. First results obtained from the scientific drilling, coring and logging allowed us to characterize the urban subsurface geology and hydrology adjacent to the Institute of Earth Sciences Jaume Almera (ICTJA-CSIC) in Barcelona. The subsurface geology and structural picture has been completed with recent geophysical studies and monitoring results. The upper section of Almera-1 214m deep hole was cased with PVC after drilling and after the logging operations. An open hole interval was left from 112m to TD (Paleozoic section). Almera-2 drilling reached 46m and was cased also with PVC to 44m. Since completion of the drilling in 2011, both Almera-1 and Almera-2 have been extensively used for research purposes, tests, training, hydrological and geophysical monitoring. A complete set of geophysical logging measurements and borehole oriented images were acquired in open hole mode of the entire Almera-1 section. Open hole measurements included acoustic and optical imaging, spectral natural gamma ray, full wave acoustic logging, magnetic susceptibility, hydrochemical-temperature logs and fluid sampling. Through casing (PVC casing) measurements included spectral gamma ray logging, full wave sonic and acoustic televiewer. A Quaternary to Paleozoic section was characterized based on the geophysical logging and borehole images interpretation and also on the complete set of (wireline) cores of the entire section. Sample availability was intended for geological macro and micro-facies detailed characterization, mineralogical and

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

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.

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.

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.

Integrating experimental and numerical methods for a scenario-based quantitative assessment of subsurface energy storage options

Science.gov (United States)

Kabuth, Alina; Dahmke, Andreas; Hagrey, Said Attia al; Berta, Márton; Dörr, Cordula; Koproch, Nicolas; Köber, Ralf; Köhn, Daniel; Nolde, Michael; Tilmann Pfeiffer, Wolf; Popp, Steffi; Schwanebeck, Malte; Bauer, Sebastian

2016-04-01

Within the framework of the transition to renewable energy sources ("Energiewende"), the German government defined the target of producing 60 % of the final energy consumption from renewable energy sources by the year 2050. However, renewable energies are subject to natural fluctuations. Energy storage can help to buffer the resulting time shifts between production and demand. Subsurface geological structures provide large potential capacities for energy stored in the form of heat or gas on daily to seasonal time scales. In order to explore this potential sustainably, the possible induced effects of energy storage operations have to be quantified for both specified normal operation and events of failure. The ANGUS+ project therefore integrates experimental laboratory studies with numerical approaches to assess subsurface energy storage scenarios and monitoring methods. Subsurface storage options for gas, i.e. hydrogen, synthetic methane and compressed air in salt caverns or porous structures, as well as subsurface heat storage are investigated with respect to site prerequisites, storage dimensions, induced effects, monitoring methods and integration into spatial planning schemes. The conceptual interdisciplinary approach of the ANGUS+ project towards the integration of subsurface energy storage into a sustainable subsurface planning scheme is presented here, and this approach is then demonstrated using the examples of two selected energy storage options: Firstly, the option of seasonal heat storage in a shallow aquifer is presented. Coupled thermal and hydraulic processes induced by periodic heat injection and extraction were simulated in the open-source numerical modelling package OpenGeoSys. Situations of specified normal operation as well as cases of failure in operational storage with leaking heat transfer fluid are considered. Bench-scale experiments provided parameterisations of temperature dependent changes in shallow groundwater hydrogeochemistry. As a

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.

Analysis of residual stress in subsurface layers after precision hard machining of forging tools

Directory of Open Access Journals (Sweden)

Czan Andrej

2018-01-01

Full Text Available This paper is focused on analysis of residual stress of functional surfaces and subsurface layers created by precision technologies of hard machining for progressive constructional materials of forging tools. Methods of experiments are oriented on monitoring of residual stress in surface which is created by hard turning (roughing and finishing operations. Subsequently these surfaces were etched in thin layers by electro-chemical polishing. The residual stress was monitored in each etched layer. The measuring was executed by portable X-ray diffractometer for detection of residual stress and structural phases. The results significantly indicate rise and distribution of residual stress in surface and subsurface layers and their impact on functional properties of surface integrity.

CLASSIFICATION OF THE MGR SUBSURFACE EXCAVATION SYSTEM

International Nuclear Information System (INIS)

R. Garrett

1999-01-01

The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) subsurface excavation system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

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.

Applications of electrical resistance tomography to subsurface environmental restoration

Energy Technology Data Exchange (ETDEWEB)

Ramirez, A.L. [Lawrence Livermore National Lab., CA (United States); Daily, W.D.

1994-11-15

We are developing a new imaging technique, Electrical Resistance Tomography (ERT), to map subsurface liquids as flow occurs during natural or clean-up processes and to map geologic structure. Natural processes (such as surface water infiltrating the vadose zone) and man-induced processes (such as tank leaks and clean-up processes such as steam injection), can create changes in a soil`s electrical properties that are readily measured. We have conducted laboratory and a variety of field experiments to investigate the capabilities and limitations of ERT for imaging underground structures and processes. In the last four years we have used ERT to successfully monitor several field processes including: a subsurface steam injection process (for VOC removal), an air injection process (below the water table) for VOC removal, water infiltration through the vadose zone, radio-frequency heating, ohmic heating, and tank and pond leaks. The information derived from ERT can be used by remediation projects to: detect and locate leaks, determine the effectiveness of clean-up processes, select appropriate clean-up alternatives, and to verify the installation and performance of subsurface barriers.

Subsurface biogenic gas rations associated with hydrocarbon contamination

International Nuclear Information System (INIS)

Marrin, D.L.

1991-01-01

Monitoring the in situ bioreclamation of organic chemicals in soil is usually accomplished by collecting samples from selected points during the remediation process. This technique requires the installation and sampling of soil borings and does not allow for continuous monitoring. The analysis of soil vapor overlying hydrocarbon-contaminated soil and groundwater has been used to detect the presence of nonaqueous phase liquids (NAPL) and to locate low-volatility hydrocarbons that are not directly detected by more conventional soil gas methods. Such soil vapor sampling methods are adaptable to monitoring the in situ bioremediation of soil and groundwater contamination. This paper focuses on the use of biogenic gas ratio in detecting the presence of crude oil and gasoline in the subsurface

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 ...

CLASSIFICATION OF THE MGR SUBSURFACE VENTILATION SYSTEM

International Nuclear Information System (INIS)

R.J. Garrett

1999-01-01

The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) subsurface ventilation system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P7 ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

Subsurface material identification and sensor selection

Science.gov (United States)

T, H.; Reghunadh, R.; Ramesh, M. V.

2017-12-01

In India, most of the landslides occur during monsoon season and causes huge loss of life and property. Design of an early warning system for highly landslide prone area will reduce losses to a great extent. The in-situ monitoring systems needs deployment of several sensors inside a borehole for monitoring a particular slope. Amrita Center for Wireless Networks and Applications (AmritaWNA), Amrita University has designed, developed and deployed a Wireless Sensor Network (WSN) for real time landslide monitoring using geotechnical instruments and sensors like rain gauge, moisture sensor, piezometer, strain gauge, tilt meter and geophone inside a Deep Earth Probe (DEP) at different locations. These sensors provide point measurements of the subsurface at a higher accuracy. Every landslide prone terrain is unique with respect to its geology, hydrological conditions, meteorological conditions, velocity of movement etc. The decision of installing different geotechnical instruments in a landslide prone terrain is a crucial step to be considered. Rain gauge, moisture sensor, and piezometer are usually used in clay rich areas to sense the moisture and pore pressure values. Geophone and Crack meter are instruments used in rocky areas to monitor cracks and vibrations associated with a movement. Inclinometer and Strain gauge are usually placed inside a casing and can be used in both rocky and soil areas. In order to place geotechnical instruments and sensors at appropriate places Electrical Resistivity Tomography (ERT) method can be used. Variation in electrical resistivity values indicate the changes in composition, layer thickness, or contaminant levels. The derived true resistivity image can be used for identifying the type of materials present in the subsurface at different depths. We have used this method for identifying the type of materials present in our site at Chandmari (Sikkim). Fig 1 shows the typical resistivity values of a particular area in Chandmari site. The

Treatment of bilge and oily drain water of tankers and current measures against combustible oil gas discharge; Tanker no biruji yudakusui shori oyobi kanensei sekiyu gas haishutsu taiskau no genjo

Energy Technology Data Exchange (ETDEWEB)

Agatsuma, Y.

1996-07-25

This paper describes the current actual conditions on treatment of bilge discharged from engine area and oily drain water from cargo area of tankers. Clean bilge among various bilges discharged from engine area such as vapor drain, fresh water, rainwater, seawater and condensed water is directly dumped into the sea after temporary storage in a clean tank. Oily bilge is produced mainly by mixing of clean bilge and leakage oil from main engines and various auxiliaries. Oily bilge is dumped into the sea under comparative monitoring of the bilge quality with the dumping standard by oil concentration monitoring and control equipment after the primary treatment in a treatment tank and the secondary treatment in a bilge separator. Oily drain water from cargo area contains water ballast for cargo oil tanks, wash water for tanks and lines, and bilge produced in pump room. The oily drain water is dumped under a specific condition. However, water ballast for specific ballast tanks is excluded from the oily drain water. 2 figs.

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.

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.

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.

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)

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.

Subsurface microbial communities and degradative capacities during trichloroethylene bioremediation

International Nuclear Information System (INIS)

Pfiffner, S.M.; Ringelberg, D.B.; Hedrick, D.B.; Phelps, T.J.; Palumbo, A.V.

1995-01-01

Subsurface amendments of air, methane, and nutrients were investigated for the in situ stimulation of trichloroethylene- degrading microorganisms at the US DOE Savannah River Integrated Demonstration. Amendments were injected into a lower horizontal well coupled with vacuum extraction from the vadose zone horizontal well. The amendments were sequenced to give increasingly more aggressive treatments. Microbial populations and degradative capacities were monitored in groundwaters samples bimonthly

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.

Relationship Between Storm Hydrograph Components and Subsurface Flow Processes in a Hilly Headwater Basin, Toyota, Japan

Science.gov (United States)

Tsujimura, M.; Asai, K.; Takei, R.

2001-05-01

Temporal and spatial distribution of tracer elements and subsurface flow processes were investigated to study relationship between storm hydrograph components and behavior of subsurface water in a headwater catchment of Toyota Hill, Aichi prefecture, central Japan. The catchment has an area of 0.857 ha with an altitude of 60 to 100 m, and is underlain by granite. The soil depth revealed by sounding test ranges from 0.5 to 4.0 m. Rain, stream, soil and ground waters were sampled once in a week, and the stream water was sampled at 5 to 60 minute intervals during rainstorms. The pressure head of subsurface water was monitored using tensiometers and piezometers nests, and the stream flow was monitored using V-notch weir. The stable isotopic ratios of deuterium and oxygen 18 and inorganic ion concentrations were determined on all water samples. The oxygen 18 isotopic ratio in stream water decreased with rainfall during the rainstorms. The ratio of event water component to the total runoff water at the peak discharge ranged from 16 to 92 %, and the event water ratio correlated with the peak discharge rate and rainfall intensity. The tesiometric data showed that the shallow subsurface water with low isotopic ratios at the lower slope discharged directly to the stream during the heavy rainstorms. The shallow subsurface flow at the lower slope and overland flow on the raiparian zone contributed much to the stream water chemistry during heavy rainstorms.

Intelligent SUBsurface Quality : Intelligent use of subsurface infrastructure for surface quality

NARCIS (Netherlands)

Hooimeijer, F.L.; Kuzniecow Bacchin, T.; Lafleur, F.; van de Ven, F.H.M.; Clemens, F.H.L.R.; Broere, W.; Laumann, S.J.; Klaassen, R.G.; Marinetti, C.

2016-01-01

This project focuses on the urban renewal of (delta) metropolises and concentrates on the question how to design resilient, durable (subsurface) infrastructure in urban renewal projects using parameters of the natural system – linking in an efficient way (a) water cycle, (b) soil and subsurface

Deep subsurface microbial processes

Science.gov (United States)

Lovley, D.R.; Chapelle, F.H.

1995-01-01

Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron acceptors just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences 1 the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of

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

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...

Brief draft on surface and subsurface storage of high level and long-lived radioactive wastes. Spent fuels synthesis file

International Nuclear Information System (INIS)

Dumas, C.; Jaecki, P.

2002-01-01

This document makes a synthesis of the results of two brief draft studies performed in 2002 about the surface and subsurface storage of spent fuels. These studies stress on the long duration aspect of the disposal: feasibility of a secular disposal facility, potential risks and safety level of such a facility, estimation of the initial investment and of operation and maintenance costs. The main points of the specifications and the input data are presented first, and then the subsurface and surface draft studies are described. Content: specifications (imposed design principles and options, dry corrosion, input data); subsurface storage (description and design options, thermal dimensioning and ventilation, geotechnical stability of the facility, subsurface water management, dry corrosion, infrastructure durability, safety, monitoring, security and physical protection, technical-economical aspects, case of Mox fuel, case of glass packages); surface storage (description and design options, thermal dimensioning and ventilation, mechanical dimensioning of the facility, dry corrosion, infrastructure durability, safety, monitoring, security and physical protection, technical-economical aspects, case of Mox fuel, case of glass packages); conclusions and perspectives. (J.S.)

Site Recommendation Subsurface Layout

International Nuclear Information System (INIS)

C.L. Linden

2000-01-01

The purpose of this analysis is to develop a Subsurface Facility layout that is capable of accommodating the statutory capacity of 70,000 metric tons of uranium (MTU), as well as an option to expand the inventory capacity, if authorized, to 97,000 MTU. The layout configuration also requires a degree of flexibility to accommodate potential changes in site conditions or program requirements. The objective of this analysis is to provide a conceptual design of the Subsurface Facility sufficient to support the development of the Subsurface Facility System Description Document (CRWMS M andO 2000e) and the ''Emplacement Drift System Description Document'' (CRWMS M andO 2000i). As well, this analysis provides input to the Site Recommendation Consideration Report. The scope of this analysis includes: (1) Evaluation of the existing facilities and their integration into the Subsurface Facility design. (2) Identification and incorporation of factors influencing Subsurface Facility design, such as geological constraints, thermal loading, constructibility, subsurface ventilation, drainage control, radiological considerations, and the Test and Evaluation Facilities. (3) Development of a layout showing an available area in the primary area sufficient to support both the waste inventories and individual layouts showing the emplacement area required for 70,000 MTU and, if authorized, 97,000 MTU

Modeling Phosphorus Losses through Surface Runoff and Subsurface Drainage Using ICECREAM.

Science.gov (United States)

Qi, Hongkai; Qi, Zhiming; Zhang, T Q; Tan, C S; Sadhukhan, Debasis

2018-03-01

Modeling soil phosphorus (P) losses by surface and subsurface flow pathways is essential in developing successful strategies for P pollution control. We used the ICECREAM model to simultaneously simulate P losses in surface and subsurface flow, as well as to assess effectiveness of field practices in reducing P losses. Monitoring data from a mineral-P-fertilized clay loam field in southwestern Ontario, Canada, were used for calibration and validation. After careful adjustment of model parameters, ICECREAM was shown to satisfactorily simulate all major processes of surface and subsurface P losses. When the calibrated model was used to assess tillage and fertilizer management scenarios, results point to a 10% reduction in total P losses by shifting autumn tillage to spring, and a 25.4% reduction in total P losses by injecting fertilizer rather than broadcasting. Although the ICECREAM model was effective in simulating surface and subsurface P losses when thoroughly calibrated, further testing is needed to confirm these results with manure P application. As illustrated here, successful use of simulation models requires careful verification of model routines and comprehensive calibration to ensure that site-specific processes are accurately represented. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

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

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

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.

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

Homogeneous Reactor Experiment (HRE) Pond cryogenic barrier technology demonstration: Pre-barrier subsurface hydrology and contaminant transport investigation

International Nuclear Information System (INIS)

Moline, G.R.

1998-03-01

The Homogeneous Reactor Experiment (HRE) Pond is the site of a former impoundment for radioactive wastes that has since been drained, filled with soil, and covered with an asphalt cap. The site is bordered to the east and south by a tributary that empties into Melton Branch Creek and that contains significant concentrations of radioactive contaminants, primarily 90 Sr. Because of the proximity of the tributary to the HRE disposal site and the probable flow of groundwater from the site to the tributary, it is hypothesized that the HRE Pond is a source of contamination to he creek. As a means for temporary containment of contaminants within the impoundment, a cryogenic barrier technology demonstration was initiated in FY96 with a background hydrologic investigation that continued through FY97. Cryogenic equipment installation was completed in FY97, and freezing was initiated in September of 1997. This report documents the results of a hydrologic and geologic investigation of the HRE Pond/cryogenic barrier site. The purpose of this investigation is to evaluate the hydrologic conditions within and around the impoundment in order to meet the following objectives: (1) to provide a pre-barrier subsurface hydrologic baseline for post-barrier performance assessment; (2) to confirm that the impoundment is hydraulically connected to the surrounding sediments; and (3) to determine the likely contaminant exit pathways from the impoundment. The methods of investigation included water level and temperature monitoring in a network of wells and standpipes in and surrounding the impoundment, a helium tracer test conducted under ambient flow conditions, and geologic logging during the drilling of boreholes for installation of cryogenic probes and temperature monitoring wells

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.

Naval Arctic Research Laboratory (NARL) Subsurface Containment Berm Investigation

Science.gov (United States)

2015-10-01

Degree-Days CRREL Cold Regions Research and Engineering Laboratory ERDC U.S. Army Engineer Research and Development Center FWENC Foster Wheeler ...contract with the Navy, Foster Wheeler Environmental Corporation (FWENC) constructed a subsurface containment berm at the airfield of the Naval...659J91.61 ncURE 3- 3 NAVAl.. AACnC R(Sf.ARCH l,.ASORATORY POINT 9ARROW. AlASKA AS-BUILT CONTAINMENT BERM EXTENSION AND MONITORING WELLS FOSTER W

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

isolated on a pedicle, has also been protected from excessive oesophageal endoluminal pressures by means of a multi-fenestrated two way endooesophageal drain (IED, two way tube type Salem). Oesophageal drain has the finality of relieving tension and monitoring the healing of the oesophageal repair.

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

Transport of Chemical Vapors from Subsurface Sources to Atmosphere as Affected by Shallow Subsurface and Atmospheric Conditions

Science.gov (United States)

Rice, A. K.; Smits, K. M.; Hosken, K.; Schulte, P.; Illangasekare, T. H.

2012-12-01

experiments. Water saturation, capillary pressure, air and soil temperature, and relative humidity were continuously monitored. Aqueous TCE was injected into the tank below the water table and allowed to volatilize. TCE concentration exiting the tank head space was measured through interval sampling by direct injection into a gas chromatograph. To quantify the transient concentration of TCE vapor in the soil pore space a novel use of Solid Phase Micro-Extraction (SPME) was developed. Results from our numerical simulations were compared with the experimental data, which demonstrated the importance of considering the interaction of the atmosphere with the subsurface in conceptualization and numerical model development. Results also emphasize that soil saturation and transient sorption have a significant effect on vapor transport through the vadose zone. Follow-up tests and detailed analyses are still underway. Additional applications of this work include carbon sequestration leakage, methane contamination in the shallow subsurface and environmental impact of hydraulic fracturing.

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.

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...

Subsurface remote sensing

International Nuclear Information System (INIS)

Schweitzer, Jeffrey S.; Groves, Joel L.

2002-01-01

Subsurface remote sensing measurements are widely used for oil and gas exploration, for oil and gas production monitoring, and for basic studies in the earth sciences. Radiation sensors, often including small accelerator sources, are used to obtain bulk properties of the surrounding strata as well as to provide detailed elemental analyses of the rocks and fluids in rock pores. Typically, instrument packages are lowered into a borehole at the end of a long cable, that may be as long as 10 km, and two-way data and instruction telemetry allows a single radiation instrument to operate in different modes and to send the data to a surface computer. Because these boreholes are often in remote locations throughout the world, the data are frequently transmitted by satellite to various locations around the world for almost real-time analysis and incorporation with other data. The complete system approach that permits rapid and reliable data acquisition, remote analysis and transmission to those making decisions is described

Development of in-situ monitoring system

International Nuclear Information System (INIS)

Lee, Bong Soo; Cho, Dong Hyun; Yoo, Wook Jae; Heo, Ji Yeon

2010-03-01

Development of in-situ monitoring system using an optical fiber to measure the real time temperature variation of subsurface water for the evaluation of flow characteristics. We describe the feasibility of developing a fiber-optic temperature sensor using a thermochromic material. A sensor-tip is fabricated by mixing of a thermochromic material powder. The relationships between the temperatures and the output voltages of detectors are determined to measure the temperature of water. It is expected that the fiber-optic temperature monitoring sensor using thermochromic material can be used to measure the real time temperature variation of subsurface water

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 ...

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.

Interconnection Studies of Subsurface River Between Bribin and Ngreneng by Using Radioisotope Tracer Iodium-131

International Nuclear Information System (INIS)

Wibagiyo

2004-01-01

Interconnection Studies of Subsurface River Between Bribin and Ngreneng by Using Radioisotope Tracer Iodium-131, carried out in 2002, the similar studies was also conducted in 2000 from subsurface river in Jurang Jero sinkhole, where the radioactivity appeared at Bribin cave 4 hours and 8 hours at Ngreneng cave. There is a question whether a subsurface river is flowing from Jurang Jero sinkhole to Bribin cave and then to Ngreneng cave, or from Jurang Jero sinkhole there is junction to Bribin and to Ngreneng. in 2002 a Germany team founded junction on up stream of river in Bribin cave, from the junction was carried out tracing which monitoring in Ngreneng cave. Where the result a junction connecting with Ngreneng cave, but the main stream in Bribin not connecting with Ngreneng. (author)

ESTIMATION OF NEAR SUBSURFACE COAL FIRE GAS EMISSIONS BASED ON GEOPHYSICAL INVESTIGATIONS

Science.gov (United States)

Chen-Brauchler, D.; Meyer, U.; Schlömer, S.; Kus, J.; Gundelach, V.; Wuttke, M.; Fischer, C.; Rueter, H.

2009-12-01

Spontaneous and industrially caused subsurface coal fires are worldwide disasters that destroy coal resources, cause air pollution and emit a large amount of green house gases. Especially in developing countries, such as China, India and Malaysia, this problem has intensified over the last 15 years. In China alone, 10 to 20 million tons of coal are believed to be lost in uncontrolled coal fires. The cooperation of developing countries and industrialized countries is needed to enforce internationally concerted approaches and political attention towards the problem. The Clean Development Mechanism (CDM) under the framework of the Kyoto Protocol may provide an international stage for financial investment needed to fight the disastrous situation. A Sino-German research project for coal fire exploration, monitoring and extinction applied several geophysical approaches in order to estimate the annual baseline especially of CO2 emissions from near subsurface coal fires. As a result of this project, we present verifiable methodologies that may be used in the CDM framework to estimate the amount of CO2 emissions from near subsurface coal fires. We developed three possibilities to approach the estimation based on (1) thermal energy release, (2) geological and geometrical determinations as well as (3) direct gas measurement. The studies involve the investigation of the physical property changes of the coal seam and bedrock during different burning stages of a underground coal fire. Various geophysical monitoring methods were applied from near surface to determine the coal volume, fire propagation, temperature anomalies, etc.

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.

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…

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.

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.

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.

Subsurface Controls on Stream Intermittency in a Semi-Arid Landscape

Science.gov (United States)

Dohman, J.; Godsey, S.; Thackray, G. D.; Hale, R. L.; Wright, K.; Martinez, D.

2017-12-01

Intermittent streams currently constitute 30% to greater than 50% of the global river network. In addition, the number of intermittent streams is expected to increase due to changes in land use and climate. These streams provide important ecosystem services, such as water for irrigation, increased biodiversity, and high rates of nutrient cycling. Many hydrological studies have focused on mapping current intermittent flow regimes or evaluating long-term flow records, but very few have investigated the underlying causes of stream intermittency. The disconnection and reconnection of surface flow reflects the capacity of the subsurface to accommodate flow, so characterizing subsurface flow is key to understanding stream drying. We assess how subsurface flow paths control local surface flows during low-flow periods, including intermittency. Water table dynamics were monitored in an intermittent reach of Gibson Jack Creek in southeastern Idaho. Four transects were delineated with a groundwater well located in the hillslope, riparian zone, and in the stream, for a total of 12 groundwater wells. The presence or absence of surface flow was determined by frequent visual observations as well as in situ loggers every 30m along the 200m study reach. The rate of surface water drying was measured in conjunction with temperature, precipitation, subsurface hydraulic conductivity, hillslope-riparian-stream connectivity and subsurface travel time. Initial results during an unusually wet year suggest different responses in reaches that were previously observed to occasionally cease flowing. Flows in the intermittent reaches had less coherent and lower amplitude diel variations during base flow periods than reaches that had never been observed to dry out. Our findings will help contribute to our understanding of mechanisms driving expansion and contraction cycles in intermittent streams, increase our ability to predict how land use and climate change will affect flow regimes, and

Corn yield under subirrigation and future climate scenarios in the Maumee river basin

Science.gov (United States)

Subirrigation has been proposed as a water table management practice to maintain appropriate soil water content during periods of high crop water demand on subsurface drained croplands in the Corn Belt. Subirrigation takes advantage of the subsurface drainage systems already installed on drained agr...

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.

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

The Serpentinite Subsurface Microbiome

Science.gov (United States)

Schrenk, M. O.; Nelson, B. Y.; Brazelton, W. J.

2011-12-01

Microbial habitats hosted in ultramafic rocks constitute substantial, globally-distributed portions of the subsurface biosphere, occurring both on the continents and beneath the seafloor. The aqueous alteration of ultramafics, in a process known as serpentinization, creates energy rich, high pH conditions, with low concentrations of inorganic carbon which place fundamental constraints upon microbial metabolism and physiology. Despite their importance, very few studies have attempted to directly access and quantify microbial activities and distributions in the serpentinite subsurface microbiome. We have initiated microbiological studies of subsurface seeps and rocks at three separate continental sites of serpentinization in Newfoundland, Italy, and California and compared these results to previous analyses of the Lost City field, near the Mid-Atlantic Ridge. In all cases, microbial cell densities in seep fluids are extremely low, ranging from approximately 100,000 to less than 1,000 cells per milliliter. Culture-independent analyses of 16S rRNA genes revealed low-diversity microbial communities related to Gram-positive Firmicutes and hydrogen-oxidizing bacteria. Interestingly, unlike Lost City, there has been little evidence for significant archaeal populations in the continental subsurface to date. Culturing studies at the sites yielded numerous alkaliphilic isolates on nutrient-rich agar and putative iron-reducing bacteria in anaerobic incubations, many of which are related to known alkaliphilic and subsurface isolates. Finally, metagenomic data reinforce the culturing results, indicating the presence of genes associated with organotrophy, hydrogen oxidation, and iron reduction in seep fluid samples. Our data provide insight into the lifestyles of serpentinite subsurface microbial populations and targets for future quantitative exploration using both biochemical and geochemical approaches.

Microbial activity in the terrestrial subsurface

International Nuclear Information System (INIS)

Kaiser, J.P.; Bollag, J.M.

1990-01-01

Little is known about the layers under the earth's crust. Only in recent years have techniques for sampling the deeper subsurface been developed to permit investigation of the subsurface environment. Prevailing conditions in the subsurface habitat such as nutrient availability, soil composition, redox potential, permeability and a variety of other factors can influence the microflora that flourish in a given environment. Microbial diversity varies between geological formations, but in general sandy soils support growth better than soils rich in clay. Bacteria predominate in subsurface sediments, while eukaryotes constitute only 1-2% of the microorganisms. Recent investigations revealed that most uncontaminated subsurface soils support the growth of aerobic heteroorganotrophic bacteria, but obviously anaerobic microorganisms also exist in the deeper subsurface habitat. The microorganisms residing below the surface of the earth are capable of degrading both natural and xenobiotic contaminants and can thereby adapt to growth under polluted conditions. (author) 4 tabs, 77 refs

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

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

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.

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

Using electrical resistance tomography to map subsurface temperatures

Science.gov (United States)

Ramirez, Abelardo L.; Chesnut, Dwayne A.; Daily, William D.

1994-01-01

A method is provided for measuring subsurface soil or rock temperatures remotely using electrical resistivity tomography (ERT). Electrical resistivity measurements are made using electrodes implanted in boreholes driven into the soil and/or at the ground surface. The measurements are repeated as some process changes the temperatures of the soil mass/rock mass. Tomographs of electrical resistivity are calculated based on the measurements using Poisson's equation. Changes in the soil/rock resistivity can be related to changes in soil/rock temperatures when: (1) the electrical conductivity of the fluid trapped in the soil's pore space is low, (2) the soil/rock has a high cation exchange capacity and (3) the temperature changes are sufficiently high. When these three conditions exist the resistivity changes observed in the ERT tomographs can be directly attributed to changes in soil/rock temperatures. This method provides a way of mapping temperature changes in subsurface soils remotely. Distances over which the ERT method can be used to monitor changes in soil temperature range from tens to hundreds of meters from the electrode locations.

Using electrical resistance tomography to map subsurface temperatures

Science.gov (United States)

Ramirez, A.L.; Chesnut, D.A.; Daily, W.D.

1994-09-13

A method is provided for measuring subsurface soil or rock temperatures remotely using electrical resistivity tomography (ERT). Electrical resistivity measurements are made using electrodes implanted in boreholes driven into the soil and/or at the ground surface. The measurements are repeated as some process changes the temperatures of the soil mass/rock mass. Tomographs of electrical resistivity are calculated based on the measurements using Poisson's equation. Changes in the soil/rock resistivity can be related to changes in soil/rock temperatures when: (1) the electrical conductivity of the fluid trapped in the soil's pore space is low, (2) the soil/rock has a high cation exchange capacity and (3) the temperature changes are sufficiently high. When these three conditions exist the resistivity changes observed in the ERT tomographs can be directly attributed to changes in soil/rock temperatures. This method provides a way of mapping temperature changes in subsurface soils remotely. Distances over which the ERT method can be used to monitor changes in soil temperature range from tens to hundreds of meters from the electrode locations. 1 fig.

Environmental geophysics: Locating and evaluating subsurface geology, geologic hazards, groundwater contamination, etc

International Nuclear Information System (INIS)

Benson, A.K.

1994-01-01

Geophysical surveys can be used to help delineate and map subsurface geology, including potential geologic hazards, the water table, boundaries of contaminated plumes, etc. The depth to the water table can be determined using seismic and ground penetrating radar (GPR) methods, and hydrogeologic and geologic cross sections of shallow alluvial aquifers can be constructed from these data. Electrical resistivity and GPR data are especially sensitive to the quality of the water and other fluids in a porous medium, and these surveys help to identify the stratigraphy, the approximate boundaries of contaminant plumes, and the source and amount of contamination in the plumes. Seismic, GPR, electromagnetic (VLF), gravity, and magnetic data help identify and delineate shallow, concealed faulting, cavities, and other subsurface hazards. Integration of these geophysical data sets can help pinpoint sources of subsurface contamination, identify potential geological hazards, and optimize the location of borings, monitoring wells, foundations for building, dams, etc. Case studies from a variety of locations will illustrate these points. 20 refs., 17 figs., 6 tabs

Monitoring radionuclides in subsurface drinking water sources near unconventional drilling operations: a pilot study

International Nuclear Information System (INIS)

Nelson, Andrew W.; Knight, Andrew W.; Eitrheim, Eric S.; Schultz, Michael K.

2015-01-01

Unconventional drilling (the combination of hydraulic fracturing and horizontal drilling) to extract oil and natural gas is expanding rapidly around the world. The rate of expansion challenges scientists and regulators to assess the risks of the new technologies on drinking water resources. One concern is the potential for subsurface drinking water resource contamination by naturally occurring radioactive materials co-extracted during unconventional drilling activities. Given the rate of expansion, opportunities to test drinking water resources in the pre- and post-fracturing setting are rare. This pilot study investigated the levels of natural uranium, lead-210, and polonium-210 in private drinking wells within 2000 m of a large-volume hydraulic fracturing operation – before and approximately one-year following the fracturing activities. Observed radionuclide concentrations in well waters tested did not exceed maximum contaminant levels recommended by state and federal agencies. No statistically-significant differences in radionuclide concentrations were observed in well-water samples collected before and after the hydraulic fracturing activities. Expanded monitoring of private drinking wells before and after hydraulic fracturing activities is needed to develop understanding of the potential for drinking water resource contamination from unconventional drilling and gas extraction activities. - Highlights: • Natural radionuclides in ground water near unconventional drilling operations were investigated. • Natural uranium ( nat U), lead-210 ( 210 Pb), and polonium-210 ( 210 Po) levels are described. • No statistically significant increases in natural radioactivity post-drilling were observed

Total selenium in irrigation drain inflows to the Salton Sea, California, April 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 the final sampling period (April 2009) of a 4-year monitoring program to characterize selenium concentrations in selected irrigation drains flowing into the Salton Sea, California. Total selenium and total suspended solids were determined in water samples. Total selenium, percent total organic carbon, and particle size were determined in sediments. Mean total selenium concentrations in water ranged from 0.98 to 22.9 micrograms per liter. Total selenium concentrations in sediment ranged from 0.078 to 5.0 micrograms per gram dry weight.

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.

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.

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

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

A mobile laboratory for surface and subsurface imaging in geo-hazard monitoring activity

Science.gov (United States)

Cornacchia, Carmela; Bavusi, Massimo; Loperte, Antonio; Pergola, Nicola; Pignatti, Stefano; Ponzo, Felice; Lapenna, Vincenzo

2010-05-01

A new research infrastructure for supporting ground-based remote sensing observations in the different phases of georisk management cycle is presented. This instrumental facility has been designed and realised by TeRN, a public-private consortium on Earth Observations and Natural Risks, in the frame of the project "ImpresAmbiente" funded by Italian Ministry of Research and University. The new infrastructure is equipped with ground-based sensors (hyperspectral cameras, thermal cameras, laser scanning and electromagnetic antennae) able to remotely map physical parameters and/or earth-surface properties (temperature, soil moisture, land cover, etc…) and to illuminate near-surface geological structures (fault, groundwater tables, landslide bodies etc...). Furthermore, the system can be used for non-invasive investigations of architectonic buildings and civil infrastructures (bridges, tunnel, road pavements, etc...) interested by natural and man-made hazards. The hyperspectral cameras can acquire high resolution images of earth-surface and cultural objects. They are operating in the Visible Near InfraRed (0.4÷1.0μm) with 1600 spatial pixel and 3.7nm of spectral sampling and in the Short Wave InfraRed (1.3÷2.5µm) spectral region with 320 spatial pixel and 5nm of spectral sampling. The IR cameras are operating in the Medium Wavelength InfraRed (3÷5µm; 640x512; NETDcultural heritage. As a consequence, laser data can be useful integrated with traditional monitoring techniques. The Laser Scanner is characterized by very high data acquisition repetition rate up to 500.000 pxl/sec with a range resolution of 0.1 mm, vertical and horizontal FoV of 310° and 360° respectively with a resolution of 0.0018°. The system is also equipped with a metric camera allows to georeference the high resolution images acquired. The electromagnetic sensors allow to obtain in near real time high-resolution 2D and 3D subsurface tomographic images. The main components are a fully automatic

Nitrogen patterns in subsurface waters of the Yzeron stream: effect of combined sewer overflows and subsurface-surface water mixing.

Science.gov (United States)

Aucour, A M; Bariac, T; Breil, P; Namour, P; Schmitt, L; Gnouma, R; Zuddas, P

2013-01-01

Urbanization subjects streams to increased nitrogen loads. Therefore studying nitrogen forms at the interface between urban stream and groundwater is important for water resource management. In this study we report results on water δ(18)O and nitrogen forms in subsurface waters of a stream (Yzeron, France). The sites studied were located upstream and downstream of combined sewer overflows (CSO) in a rural area and a periurban area, respectively. Water δ(18)O allowed us to follow the mixing of subsurface water with surface water. Dissolved organic nitrogen and organic carbon of fine sediment increased by 20-30% between rural and periurban subsurface waters in the cold season, under high flow. The highest nitrate levels were observed in rural subsurface waters in the cold season. The lowest nitrate levels were found in periurban subsurface waters in the warm season, under low flow. They corresponded to slow exchange of subsurface waters with channel water. Thus reduced exchange between surface and subsurface waters and organic-matter-rich input seemed to favor nitrate reduction in the downstream, periurban, subsurface waters impacted by CSO.

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.

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.

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

Long-term monitoring of nitrate-N transport to drainage from three agricultural clayey till fields

Science.gov (United States)

Ernstsen, V.; Olsen, P.; Rosenbom, A. E.

2015-01-01

The application of nitrogen (N) fertilisers to crops grown on tile-drained fields is necessary to sustain most modern crop production, but poses a risk to the aquatic environment since tile drains facilitate rapid transport pathways with no significant reduction in nitrate. To maintain the water quality of the aquatic environment and the provision of food from highly efficient agriculture in line with the EU's Water Framework Directive and Nitrates Directive, field-scale knowledge is imperative if there is to be differentiated N-regulation in future. This study describes nitrate-N leaching to drainage based on coherent monitoring of nitrate-N concentrations, the climate, the groundwater table and crop-specific parameters obtained over eleven years (2001-2011) at three subsurface-drained clayey till fields (1.3-2.3 ha). The monitoring results showed significant field differences in nitrate-N transport to drainage. Not only were these caused by periods of bare soil after short-season crops and N-fixing crops (pea), which have been shown to generate high nitrate-N concentrations in drainage, but by the hydrogeological field conditions that were shown to be the controlling factor of nitrate-N transport to drainage. The fields had the following characteristics: (A) the lowest mass transport (13 kg N ha-1) and fertiliser input had short-term and low-intensity drainage with the highest nitrate-N concentrations detected, representing 40% of net precipitation (226 mm) combined with low air temperatures, (B) the medium mass transport (14 kg N ha-1) had medium-term and medium-intensity drainage, representing 42% of net precipitation (471 mm) combined with periods of both low and higher air temperatures, (C) the highest mass transport (19 kg N ha-1) had long-term drainage, representing 68% of net precipitation (617 mm), but had the highest potential for in-situ soil denitrification and post-treatment (e.g. constructed wetlands) due to long periods with both high water

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.

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.

Fluvial sediment inputs to upland gravel bed rivers draining forested catchments: potential ecological impacts

Directory of Open Access Journals (Sweden)

S. D. Marks

1997-01-01

Full Text Available As identified by the detailed long-term monitoring networks at Plynlimon, increased sediment supply to upland fluvial systems is often associated with forestry land-use and practice. Literature is reviewed, in the light of recent results from Plynlimon sediment studies, to enable identification of the potential ecological impacts of fluvial particulate inputs to upland gravel bed rivers draining forested catchments similar to the headwaters of the River Severn. Both sediment transport and deposition can have significant impacts upon aquatic vertebrates, invertebrates and plants.

Cover cropping to reduce nitrate loss through subsurface drainage in the northern U.S. corn belt.

Science.gov (United States)

Strock, J S; Porter, P M; Russelle, M P

2004-01-01

Despite the use of best management practices for nitrogen (N) application rate and timing, significant losses of nitrate nitrogen (NO3(-)-N) in drainage discharge continue to occur from row crop cropping systems. Our objective was to determine whether a autumn-seeded winter rye (Secale cereale L.) cover crop following corn (Zea mays L.) would reduce NO3(-)-N losses through subsurface tile drainage in a corn-soybean [Glycine mar (L.) Merr.] cropping system in the northern Corn Belt (USA) in a moderately well-drained soil. Both phases of the corn-soybean rotation, with and without the winter rye cover crop following corn, were established in 1998 in a Normania clay loam (fine-loamy, mixed, mesic Aquic Haplustoll) soil at Lamberton, MN. Cover cropping did not affect subsequent soybean yield, but reduced drainage discharge, flow-weighted mean nitrate concentration (FWMNC), and NO3(-)-N loss relative to winter fallow, although the magnitude of the effect varied considerably with annual precipitation. Three-year average drainage discharge was lower with a winter rye cover crop than without (p = 0.06). Over three years, subsurface tile-drainage discharge was reduced 11% and NO3(-)-N loss was reduced 13% for a corn-soybean cropping system with a rye cover crop following corn than with no rye cover crop. We estimate that establishment of a winter rye cover crop after corn will be successful in one of four years in southwestern Minnesota. Cover cropping with rye has the potential to be an effective management tool for reducing NO3(-)-N loss from subsurface drainage discharge despite challenges to establishment and spring growth in the north-central USA.

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

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.

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.

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 ...

SWRO feed water quality improvement using subsurface intakes in Oman, Spain, Turks and Caicos Islands, and Saudi Arabia

KAUST Repository

Rachman, Rinaldi

2014-10-01

Water quality sampling and analysis conducted at four global locations, along the shorelines of the Arabian Sea, the Red Sea, the Mediterranean Sea, and the Caribbean Sea, demonstrated that subsurface intakes (wells) provide a robust degree of feed water treatment close to that provided by energy-intensive, conventional pretreatment systems. SDI values were reduced in virtually all cases to below 3. In vertical wells, from 70 to 100% of the TEP and 50% of the TOC and DOC found in natural seawater were removed in the aquifer. Reduction in the concentration of the organic fractions was selective based on molecular weight with the biopolymers nearly fully removed. Humic substances, building blocks, and light organic substances were removed at lesser percentages. Site geology was not the predominant factor affecting the removal efficiency, but the length of the flow path from the sea to the wells and the hydraulic retention time appear to be most significant. A comparison between vertical wells, a tunnel intake system, and a horizontal drain system at Alicante, Spain, demonstrated that the vertical wells performed best followed by the tunnel system, and the horizontal drain system which showed a breakthrough of algae and a very high organic carbon concentration. © 2014 Elsevier B.V.

COUPLING STATE-OF-THE-SCIENCE SUBSURFACE SIMULATION WITH ADVANCED USER INTERFACE AND PARALLEL VISUALIZATION: SBIR Phase I Final Report

International Nuclear Information System (INIS)

Hardeman, B.; Swenson, D.; Finsterle, S.; Zhou, Q.

2008-01-01

This is a Phase I report on a project to significantly enhance existing subsurface simulation software using leadership-class computing resources, allowing researchers to solve problems with greater speed and accuracy. Subsurface computer simulation is used for monitoring the behavior of contaminants around nuclear waste disposal and storage areas, groundwater flow, environmental remediation, carbon sequestration, methane hydrate production, and geothermal energy reservoir analysis. The Phase I project was a collaborative effort between Thunderhead Engineering (project lead and developers of a commercial pre- and post-processor for the TOUGH2 simulator) and Lawrence Berkeley National Laboratory (developers of the TOUGH2 simulator for subsurface flow). The Phase I project successfully identified the technical approaches to be implemented in Phase II.

The design of long wavelength planetary SAR sensor and its applications for monitoring shallow sub-surface of Moon and planets.

Science.gov (United States)

Kim, K.

2015-12-01

SAR observations over planetary surface have been conducted mainly in two ways. The first is the subsurface sounding, for example Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) and Shallow Surface Radar (SHARAD), using ground penetration capability of long wavelength electromagnetic waves. On the other hand, imaging SAR sensors using burst mode design have been employed to acquire surface observations in the presence of opaque atmospheres such as in the case of Venus and Titan. We propose a lightweight SAR imaging system with P/L band wavelength to cover the vertical observation gap of these planetary radar observation schemes. The sensor is for investigating prominent surface and near-subsurface geological structures and physical characteristics. Such measurements will support landers and rover missions as well as future manned missions. We evaluate required power consumption, and estimate mass and horizontal resolution, which can be as good as 3-7 meters. Initial specifications for P/L dual band SARs for the lunar case at 130 km orbital altitude were designed already based on a assumptions that sufficient size antenna (>3m width diameter or width about 3m and >10kg weight) can be equipped. Useful science measurements to be obtained include: (1) derivation of subsurface regolith depth; 2) Surface and shallow subsurface radar imaging, together with radar ranging techniques such as radargrammetry and inteferometry. The concepts in this study can be used as an important technical basis for the future solid plant/satellite missions and already proposed for the 2018 Korean Lunar mission.

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...

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 ...

Integrated geomechanical modelling for deep subsurface damage

NARCIS (Netherlands)

Wees, J.D. van; Orlic, B.; Zijl, W.; Jongerius, P.; Schreppers, G.J.; Hendriks, M.

2001-01-01

Government, E&P and mining industry increasingly demand fundamental insight and accurate predictions on subsurface and surface deformation and damage due to exploitation of subsurface natural resources, and subsurface storage of energy residues (e.g. CO2). At this moment deformation is difficult to

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.

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

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.

Program overview: Subsurface science program

International Nuclear Information System (INIS)

1994-03-01

The OHER Subsurface Science Program is DOE's core basic research program concerned with subsoils and groundwater. These practices have resulted in contamination by mixtures of organic chemicals, inorganic chemicals, and radionuclides. A primary long-term goal is to provide a foundation of knowledge that will lead to the reduction of environmental risks and to cost-effective cleanup strategies. Since the Program was initiated in 1985, a substantial amount of research in hydrogeology, subsurface microbiology, and the geochemistry of organically complexed radionuclides has been completed, leading to a better understanding of contaminant transport in groundwater and to new insights into microbial distribution and function in the subsurface environments. The Subsurface Science Program focuses on achieving long-term scientific advances that will assist DOE in the following key areas: providing the scientific basis for innovative in situ remediation technologies that are based on a concept of decontamination through benign manipulation of natural systems; understanding the complex mechanisms and process interactions that occur in the subsurface; determining the influence of chemical and geochemical-microbial processes on co-contaminant mobility to reduce environmental risks; improving predictions of contaminant transport that draw on fundamental knowledge of contaminant behavior in the presence of physical and chemical heterogeneities to improve cleanup effectiveness and to predict environmental risks

A programmable point-of-care device for external CSF drainage and monitoring.

Science.gov (United States)

Simkins, Jeffrey R; Subbian, Vignesh; Beyette, Fred R

2014-01-01

This paper presents a prototype of a programmable cerebrospinal fluid (CSF) external drainage system that can accurately measure the dispensed fluid volume. It is based on using a miniature spectrophotometer to collect color data to inform drain rate and pressure monitoring. The prototype was machined with 1 μm dimensional accuracy. The current device can reliably monitor the total accumulated fluid volume, the drain rate, the programmed pressure, and the pressure read from the sensor. Device requirements, fabrication processes, and preliminary results with an experimental set-up are also presented.

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.

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.

Comparison of export dynamics of nutrients and animal-borne estrogens from a tile-drained Midwestern agroecosystem.

Science.gov (United States)

Gall, Heather E; Sassman, Stephen A; Jenkinson, Byron; Lee, Linda S; Jafvert, Chad T

2015-04-01

Concentrated animal feeding operations (CAFOs) are known to be a source of nutrients and hormones found in surface water bodies around the world. While the fate and transport of nutrients have been studied for decades, much less research has been conducted on the fate and transport of hormones. To facilitate a comparison of nutrient and hormone export dynamics from farm fields, nitrate + nitrite (N), dissolved reactive phosphorus (DRP), 17α- and 17β-estradiol (E2), estrone (E1), and estriol (E3) were monitored in a tile drain and receiving ditch for one year on a working farm in north central Indiana. Repeated animal waste applications led to high frequency detection of hormones (>50% in tile drain; >90% in the ditch) and nutrients (>70% for DRP; 100% for N). Hydrologic variability was found to be a dominant factor controlling export of N, DRP, and E1 to the drain and ditch. Of the estrogens, the temporal trend in E1 export was most similar to that of DRP. Differences in temporal export between P and the other estrogens likely were due to differences in the biogeochemical processes that affect their fate and transport within the agroecosystem. During short periods when the flowrate exceeded the 80(th) percentile for the year, over 70% of the total mass export of DRP and E1 occurred for the year in both the tile drain and ditch, demonstrating the importance of high-flow events. Therefore, best management practices must be effective during large flow events to substantially reduce transport to downstream locations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Monitoring Corps Projects With Web Cameras (Ice Engineering. Number 35, September 2002)

National Research Council Canada - National Science Library

2002-01-01

..., monitoring of endangered species, and especially now increased security. Physical monitoring can drain personnel and equipment resources, especially if the site is remote, and important events may be missed because of unfortunate timing...

Subsurface waste disposal by means of wells - A selective annotated bibliography

Science.gov (United States)

Rima, Donald Robert; Chase, Edith B.; Myers, Beverly M.

1971-01-01

Subsurface waste disposal by means of wells is the practice of using drilled wells to inject unwanted substances into underground rock formations. The use of wells for this purpose is not a new idea. As long ago as the end of the last century, it was common practice to drill wells for the express purpose of draining swamps and small lakes to reclaim the land for agricultural purposes. A few decades later in the 1920's and 1930's many oil companies began using injection wells to dispose of oil-field brines and to repressurize oil reservoirs. During World War II, the Atomic Energy Commission began using injection wells to dispose of certain types of radioactive wastes. More recently, injection wells have been drilled to dispose of a variety of byproducts of industrial processes. The number of such wells has increased rapidly since Congress passed the Clean Streams Act of 1966, which restricted the discharge of waste into surface waters.Many scientists and public officials question the propriety of using the term "disposal" when referring to the underground injection of wastes. Their reasons are that underground injection is not, as many advocates claim, "a complete and final answer" to the waste-disposal problem. Rather, it is merely a process wherein the injected wastes are committed to the subsurface with uncertainty as to their ultimate fate or limits of confinement. In effect, the wastes, undiminished and unchanged, are removed from the custody of man and placed in the custody of nature.Although the concept of waste-injection wells is relatively simple, the effects of waste injection can be very complex, particularly when dealing with the exotic and complex components of some industrial wastes. Besides the physical forces of injection, there are many varied interactions between the injected wastes and the materials within the injection zone. Because these changes occur out of sight in the subsurface, they are difficult to assess and not generally understood. In

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....

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.

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.

The underwater installation of a drained geomembrane system on Lost Creek Dam

International Nuclear Information System (INIS)

Onken, S.; Harlan, R.C.; Wilkes, J.; Vaschetti, G.

1998-01-01

Lost Creek Dam was constructed in California around 1923. It is a 122 foot high concrete arch dam with a crest elevation of 3,287 feet and a crest length of 490 feet. Over the years, the dam and the condition of the concrete face have deteriorated. The concrete is porous and seeps water along the entire downstream face. In winter, the seeping water freezes, penetrates the concrete and causes expansion and spalling of the concrete surface. In some places, the concrete has very low strength to a depth of a foot or more, rendering the dam only marginally safe. Seven mitigative measures were identified as possible solutions to the problem. It was determined that the seepage of the water through the concrete dam could be stopped with the installation of a geomembrane to the upstream face. This paper describes the unique underwater installation of a drained geomembrane system on the concrete face of the dam. This was the first ever installation of a drained geomembrane system on an entire dam using divers. Monitoring will determine the success of the project, and whether the seepage of the water through the porous concrete had been reduced sufficiently to stop the deterioration of the concrete on the downstream face. 2 refs., 12 figs

SUBSURFACE CONSTRUCTION AND DEVELOPMENT ANALYSIS

International Nuclear Information System (INIS)

N.E. Kramer

1998-01-01

The purpose of this analysis is to identify appropriate construction methods and develop a feasible approach for construction and development of the repository subsurface facilities. The objective of this analysis is to support development of the subsurface repository layout for License Application (LA) design. The scope of the analysis for construction and development of the subsurface Repository facilities covers: (1) Excavation methods, including application of knowledge gained from construction of the Exploratory Studies Facility (ESF). (2) Muck removal from excavation headings to the surface. This task will examine ways of preventing interference with other subsurface construction activities. (3) The logistics and equipment for the construction and development rail haulage systems. (4) Impact of ground support installation on excavation and other construction activities. (5) Examination of how drift mapping will be accomplished. (6) Men and materials handling. (7) Installation and removal of construction utilities and ventilation systems. (8) Equipping and finishing of the emplacement drift mains and access ramps to fulfill waste emplacement operational needs. (9) Emplacement drift and access mains and ramps commissioning prior to handover for emplacement operations. (10) Examination of ways to structure the contracts for construction of the repository. (11) Discussion of different construction schemes and how to minimize the schedule risks implicit in those schemes. (12) Surface facilities needed for subsurface construction activities

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.

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

Model for the prediction of subsurface strata movement due to underground mining

Science.gov (United States)

Cheng, Jianwei; Liu, Fangyuan; Li, Siyuan

2017-12-01

The problem of ground control stability due to large underground mining operations is often associated with large movements and deformations of strata. It is a complicated problem, and can induce severe safety or environmental hazards either at the surface or in strata. Hence, knowing the subsurface strata movement characteristics, and making any subsidence predictions in advance, are desirable for mining engineers to estimate any damage likely to affect the ground surface or subsurface strata. Based on previous research findings, this paper broadly applies a surface subsidence prediction model based on the influence function method to subsurface strata, in order to predict subsurface stratum movement. A step-wise prediction model is proposed, to investigate the movement of underground strata. The model involves a dynamic iteration calculation process to derive the movements and deformations for each stratum layer; modifications to the influence method function are also made for more precise calculations. The critical subsidence parameters, incorporating stratum mechanical properties and the spatial relationship of interest at the mining level, are thoroughly considered, with the purpose of improving the reliability of input parameters. Such research efforts can be very helpful to mining engineers’ understanding of the moving behavior of all strata over underground excavations, and assist in making any damage mitigation plan. In order to check the reliability of the model, two methods are carried out and cross-validation applied. One is to use a borehole TV monitor recording to identify the progress of subsurface stratum bedding and caving in a coal mine, the other is to conduct physical modelling of the subsidence in underground strata. The results of these two methods are used to compare with theoretical results calculated by the proposed mathematical model. The testing results agree well with each other, and the acceptable accuracy and reliability of the

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

Modeling subsurface stormflow initiation in low-relief landscapes

Science.gov (United States)

Hopp, Luisa; Vaché, Kellie B.; Rhett Jackson, C.; McDonnell, Jeffrey J.

2015-04-01

Shallow lateral subsurface flow as a runoff generating mechanism at the hillslope scale has mostly been studied in steeper terrain with typical hillside angles of 10 - 45 degrees. These studies have shown that subsurface stormflow is often initiated at the interface between a permeable upper soil layer and a lower conductivity impeding layer, e.g. a B horizon or bedrock. Many studies have identified thresholds of event size and soil moisture states that need to be exceeded before subsurface stormflow is initiated. However, subsurface stormflow generation on low-relief hillslopes has been much less studied. Here we present a modeling study that investigates the initiation of subsurface stormflow on low-relief hillslopes in the Upper Coastal Plain of South Carolina, USA. Hillslopes in this region typically have slope angles of 2-5 degrees. Topsoils are sandy, underlain by a low-conductivity sandy clay loam Bt horizon. Subsurface stormflow has only been intercepted occasionally in a 120 m long trench, and often subsurface flow was not well correlated with stream signals, suggesting a disconnect between subsurface flow on the hillslopes and stream flow. We therefore used a hydrologic model to better understand which conditions promote the initiation of subsurface flow in this landscape, addressing following questions: Is there a threshold event size and soil moisture state for producing lateral subsurface flow? What role does the spatial pattern of depth to the impeding clay layer play for subsurface stormflow dynamics? We reproduced a section of a hillslope, for which high-resolution topographic data and depth to clay measurements were available, in the hydrologic model HYDRUS-3D. Soil hydraulic parameters were based on experimentally-derived data. The threshold analysis was first performed using hourly climate data records for 2009-2010 from the study site to drive the simulation. For this period also trench measurements of subsurface flow were available. In addition

Fiber Optic Bragg Grating Sensors for Thermographic Detection of Subsurface Anomalies

Science.gov (United States)

Allison, Sidney G.; Winfree, William P.; Wu, Meng-Chou

2009-01-01

Conventional thermography with an infrared imager has been shown to be an extremely viable technique for nondestructively detecting subsurface anomalies such as thickness variations due to corrosion. A recently developed technique using fiber optic sensors to measure temperature holds potential for performing similar inspections without requiring an infrared imager. The structure is heated using a heat source such as a quartz lamp with fiber Bragg grating (FBG) sensors at the surface of the structure to detect temperature. Investigated structures include a stainless steel plate with thickness variations simulated by small platelets attached to the back side using thermal grease. A relationship is shown between the FBG sensor thermal response and variations in material thickness. For comparison, finite element modeling was performed and found to agree closely with the fiber optic thermography results. This technique shows potential for applications where FBG sensors are already bonded to structures for Integrated Vehicle Health Monitoring (IVHM) strain measurements and can serve dual-use by also performing thermographic detection of subsurface anomalies.

Assessment of surface and subsurface ground disturbance due to underground mining

International Nuclear Information System (INIS)

Khair, A.W.

1994-01-01

This paper presents highlights of the research carried out at West Virginia University in order to assess surface and subsurface ground disturbance due to longwall mining. Extensive instrumentation and measurements have been made over three longwall mines in northern West Virginia during a three-year period. Various monitoring techniques including full profile borehole extensometer, full profile borehole inclinometers, time domain reflectometry, sonic reflection technique, a unique mechanical grouting method, photographic and visual observations, standard surveying, and water-level measurements were utilized. The paper's emphasis is first on surface ground movement and its impact on integrity of surface ground and structures and second on type and magnitude of subsurface ground movements associated with mine geometry and geology. A subsidence prediction model based on implementation of both mechanisms of ground movement around the excavation and the geologic and geotechnical properties of the rock/coal surrounding the excavation has been developed. 8 refs., 14 figs., 1 tab

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.

Subsurface Shielding Source Term Specification Calculation

International Nuclear Information System (INIS)

S.Su

2001-01-01

The purpose of this calculation is to establish appropriate and defensible waste-package radiation source terms for use in repository subsurface shielding design. This calculation supports the shielding design for the waste emplacement and retrieval system, and subsurface facility system. The objective is to identify the limiting waste package and specify its associated source terms including source strengths and energy spectra. Consistent with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M and O 2001, p. 15), the scope of work includes the following: (1) Review source terms generated by the Waste Package Department (WPD) for various waste forms and waste package types, and compile them for shielding-specific applications. (2) Determine acceptable waste package specific source terms for use in subsurface shielding design, using a reasonable and defensible methodology that is not unduly conservative. This calculation is associated with the engineering and design activity for the waste emplacement and retrieval system, and subsurface facility system. The technical work plan for this calculation is provided in CRWMS M and O 2001. Development and performance of this calculation conforms to the procedure, AP-3.12Q, Calculations

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.)

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.)

Simulation and validation of concentrated subsurface lateral flow paths in an agricultural landscape

Science.gov (United States)

Zhu, Q.; Lin, H. S.

2009-08-01

The importance of soil water flow paths to the transport of nutrients and contaminants has long been recognized. However, effective means of detecting concentrated subsurface flow paths in a large landscape are still lacking. The flow direction and accumulation algorithm based on single-direction flow algorithm (D8) in GIS hydrologic modeling is a cost-effective way to simulate potential concentrated flow paths over a large area once relevant data are collected. This study tested the D8 algorithm for simulating concentrated lateral flow paths at three interfaces in soil profiles in a 19.5-ha agricultural landscape in central Pennsylvania, USA. These interfaces were (1) the interface between surface plowed layers of Ap1 and Ap2 horizons, (2) the interface with subsoil water-restricting clay layer where clay content increased to over 40%, and (3) the soil-bedrock interface. The simulated flow paths were validated through soil hydrologic monitoring, geophysical surveys, and observable soil morphological features. The results confirmed that concentrated subsurface lateral flow occurred at the interfaces with the clay layer and the underlying bedrock. At these two interfaces, the soils on the simulated flow paths were closer to saturation and showed more temporally unstable moisture dynamics than those off the simulated flow paths. Apparent electrical conductivity in the soil on the simulated flow paths was elevated and temporally unstable as compared to those outside the simulated paths. The soil cores collected from the simulated flow paths showed significantly higher Mn content at these interfaces than those away from the simulated paths. These results suggest that (1) the D8 algorithm is useful in simulating possible concentrated subsurface lateral flow paths if used with appropriate threshold value of contributing area and sufficiently detailed digital elevation model (DEM); (2) repeated electromagnetic surveys can reflect the temporal change of soil water storage

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.

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.

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....

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

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

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.

Component-based framework for subsurface simulations

International Nuclear Information System (INIS)

Palmer, B J; Fang, Yilin; Hammond, Glenn; Gurumoorthi, Vidhya

2007-01-01

Simulations in the subsurface environment represent a broad range of phenomena covering an equally broad range of scales. Developing modelling capabilities that can integrate models representing different phenomena acting at different scales present formidable challenges both from the algorithmic and computer science perspective. This paper will describe the development of an integrated framework that will be used to combine different models into a single simulation. Initial work has focused on creating two frameworks, one for performing smooth particle hydrodynamics (SPH) simulations of fluid systems, the other for performing grid-based continuum simulations of reactive subsurface flow. The SPH framework is based on a parallel code developed for doing pore scale simulations, the continuum grid-based framework is based on the STOMP (Subsurface Transport Over Multiple Phases) code developed at PNNL Future work will focus on combining the frameworks together to perform multiscale, multiphysics simulations of reactive subsurface flow

The impact of urbanization on subsurface flow paths - A paired-catchment isotopic study

Science.gov (United States)

Bonneau, Jeremie; Burns, Matthew J.; Fletcher, Tim D.; Witt, Roman; Drysdale, Russell N.; Costelloe, Justin F.

2018-06-01

Urbanization disturbs groundwater flow through the sealing of native soils with impervious surfaces and through modifications to the subsoil by constructed drainage and other infrastructure (trenches and excavations, e.g. water supply). The impact of these disturbances on groundwater contributions to urban streams (i.e. baseflow) is poorly understood. While high flows caused by impervious runoff to streams are a common focus of urban studies, the route taken by groundwater to become streamflow in urban landscapes is not generally considered. To assess the impact of urbanization on groundwater sources to streams, both rainfall and baseflow were sampled weekly for stable isotopes of water in two nearby streams-one draining a peri-urban catchment and the other draining a forested, natural catchment. In addition, to study the rate of groundwater discharge to the stream, monthly baseflow recession behavior was investigated. We found that baseflow in the forested catchment was constant in stable isotope values (δ18O = -5.73‰ ± 0.14‰) throughout the year. Monthly baseflow recession constants were close to 1 and had little variation (ranging 0.951-0.992), indicating a well-mixed groundwater store and long residence times. In contrast, the urban baseflow isotopic composition featured distinct seasonal variations (δ18O = -3.35‰ ± 1.20‰ from October to March and δ18O = -4.54‰ ± 0.43‰ from April to September) and high week-to-week variability in summer, reflecting a contribution of recent rainfall to baseflow. Recession constants were lower (ranging 0.727-0.955) with pronounced seasonal variations, suggesting shorter residence times and the likely presence of a variety of stores and pathways. These results provide evidence that the urban catchment has diversified groundwater pathways, and its groundwater storage is drained faster than that of the forested catchment. It highlights some of the subsurface hydrological consequences of urbanization. Restoring low

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.

UNSAT-H infiltration model calibration at the Subsurface Disposal Area, Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

Martian, P.

1995-10-01

Soil moisture monitoring data from the expanded neutron probe monitoring network located at the Subsurface Disposal Area (SDA) of the Idaho National Engineering Laboratory (INEL) were used to calibrate numerical infiltration models for 15 locations within and near the SDA. These calibrated models were then used to simulate infiltration into the SDA surficial sediments and underlying basalts for the entire operational period of the SDA (1952--1995). The purpose of performing the simulations was to obtain a time variant infiltration source term for future subsurface pathway modeling efforts as part of baseline risk assessment or performance assessments. The simulation results also provided estimates of the average recharge rate for the simulation period and insight into infiltration patterns at the SDA. These results suggest that the average aquifer recharge rate below the SDA may be at least 8 cm/yr and may be as high as 12 cm/yr. These values represent 38 and 57% of the average annual precipitation occurring at the INEL, respectively. The simulation results also indicate that the maximum evaporative depth may vary between 28 and 148 cm and is highly dependent on localized lithology within the SDA

Quantifying induced effects of subsurface renewable energy storage

Science.gov (United States)

Bauer, Sebastian; Beyer, Christof; Pfeiffer, Tilmann; Boockmeyer, Anke; Popp, Steffi; Delfs, Jens-Olaf; Wang, Bo; Li, Dedong; Dethlefsen, Frank; Dahmke, Andreas

2015-04-01

New methods and technologies for energy storage are required for the transition to renewable energy sources. Subsurface energy storage systems such as salt caverns or porous formations offer the possibility of hosting large amounts of energy or substance. When employing these systems, an adequate system and process understanding is required in order to assess the feasibility of the individual storage option at the respective site and to predict the complex and interacting effects induced. This understanding is the basis for assessing the potential as well as the risks connected with a sustainable usage of these storage options, especially when considering possible mutual influences. For achieving this aim, in this work synthetic scenarios for the use of the geological underground as an energy storage system are developed and parameterized. The scenarios are designed to represent typical conditions in North Germany. The types of subsurface use investigated here include gas storage and heat storage in porous formations. The scenarios are numerically simulated and interpreted with regard to risk analysis and effect forecasting. For this, the numerical simulators Eclipse and OpenGeoSys are used. The latter is enhanced to include the required coupled hydraulic, thermal, geomechanical and geochemical processes. Using the simulated and interpreted scenarios, the induced effects are quantified individually and monitoring concepts for observing these effects are derived. This presentation will detail the general investigation concept used and analyze the parameter availability for this type of model applications. Then the process implementation and numerical methods required and applied for simulating the induced effects of subsurface storage are detailed and explained. Application examples show the developed methods and quantify induced effects and storage sizes for the typical settings parameterized. This work is part of the ANGUS+ project, funded by the German Ministry

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.

Subsurface microbial habitats on Mars

Science.gov (United States)

Boston, P. J.; Mckay, C. P.

1991-01-01

We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on geothermal hot spots existing below the near or deep subsurface of Mars. Recent advances in the comparatively new field of deep subsurface microbiology have revealed previously unsuspected rich aerobic and anaerobic microbal communities far below the surface of the Earth. Such habitats, protected from the grim surface conditions on Mars, could receive warmth from below and maintain water in its liquid state. In addition, geothermally or volcanically reduced gases percolating from below through a microbiologically active zone could provide the reducing power needed for a closed or semi-closed microbial ecosystem to thrive.

Monitoring of Underground Coal Gasification

Energy Technology Data Exchange (ETDEWEB)

Yang, X. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wagoner, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ramirez, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2012-08-31

For efficient and responsible UCG operations, a UCG process must be monitored in the following three categories: 1) process parameters such as injection and product gas flow rates, temperature, pressure and syngas content and heating value; 2) geomechanical parameters, e.g., cavity and coal seam pressures, cavity development, subsidence and ground deformation; and 3) environmental parameters, e.g., groundwater chemistry and air quality. This report focuses on UCG monitoring with geophysical techniques that can contribute to monitoring of subsurface temperature, cavity development, burn front, subsidence and deformation.

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

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)

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.

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 )

Functional design criteria for FY 1993-2000 groundwater monitoring wells

International Nuclear Information System (INIS)

Williams, B.A.

1996-01-01

The purpose of this revision is to update the Line Item Project, 93-L-GFW-152 Functional Design Criteria (FDC) to reflect changes approved in change control M-24-91-6, Engineering Change Notices (ECNs), and expand the scope to include subsurface investigations along with the borehole drilling. This revision improves the ability and effectiveness of maintaining RCRA and Operational groundwater compliance by combining borehole and well drilling with subsurface data gathering objectives. The total projected number of wells to be installed under this project has decreased from 200 and the scope has been broadened to include additional subsurface investigation activities that usually occur simultaneously with most traditional borehole drilling and monitoring well installations. This includes borehole hydrogeologic characterization activities, and vadose monitoring. These activities are required under RCRA 40 CFR 264 and 265 and WAC 173-303 for site characterization, groundwater and vadose assessment and well placement

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

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)

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...

Pleural subxyphoid drain confers better pulmonary function and clinical outcomes in chronic obstructive pulmonary disease after off-pump coronary artery bypass grafting: a randomized controlled trial.

Science.gov (United States)

Guizilini, Solange; Viceconte, Marcela; Esperança, Gabriel Tavares da M; Bolzan, Douglas W; Vidotto, Milena; Moreira, Rita Simone L; Câncio, Andréia Azevedo; Gomes, Walter J

2014-01-01

To evaluate the lung function and clinical outcome in severe chronic obstructive pulmonary disease in patients undergoing off-pump coronary artery bypass grafting with left internal thoracic artery graft, comparing the pleural drain insertion in the intercostal versus subxyphoid region. A randomized controlled trial. Chronic obstructive pulmonary disease patients were randomized into two groups according pleural drain site: II group (n=27) - pleural drain in intercostal space; SI group (n=29) - pleural drain in the subxyphoid region. Spirometry values (Forced Vital Capacity - and Forced expiratory volume in 1 second) were obtained on preoperative and 1, 3 and 5 postoperative days. Chest x-ray from preoperative until postoperative day 5 (POD5) was performed for monitoring respiratory events, such as atelectasis and pleural effusion. Pulmonary shunt fraction and pain score was evaluate preoperatively and on postoperative day 1. In both groups there was a significant decrease of the spirometry values (Forced Vital Capacity and Forced expiratory volume in 1 second) until POD5 (Ppleural drainage in severe Chronic obstructive pulmonary disease patients determined better preservation and recovery of pulmonary capacity and volumes with lower pulmonary shunt fraction and better clinical outcomes on early postoperative off-pump coronary artery bypass grafting.

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...

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

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

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...

Pleurotomy with subxyphoid pleural drain affords similar effects to pleural integrity in pulmonary function after off-pump coronary artery bypass graft.

Science.gov (United States)

Guizilini, Solange; Bolzan, Douglas W; Faresin, Sonia M; Ferraz, Raquel F; Tavolaro, Kelly; Cancio, Andrea A; Gomes, Walter J

2012-01-25

Exacerbation of pulmonary dysfunction has been reported in patients receiving a pleural drain inserted through the intercostal space in comparison to patients with an intact pleura undergoing coronary artery bypass grafting (CABG). Evidence suggests that shifting the site of pleural drain insertion to the subxyphoid position minimizes chest wall trauma and preserves respiratory function in the early postoperative period. The aim of this study was to compare the pulmonary function parameters, clinical outcomes, and pain score between patients undergoing pleurotomy with pleural drain placed in the subxyphoid position and patients with intact pleural cavity after off-pump CABG (OPCAB) using left internal thoracic artery (LITA). Seventy-one patients were allocated into two groups: I (n = 38 open left pleural cavity and pleural drain inserted in the subxyphoid position); II (n = 33 intact pleural cavity). Pulmonary function tests and clinical parameters were recorded preoperatively and on postoperative days (POD) 1, 3 and 5. Arterial blood gas analysis and shunt fraction were evaluated preoperatively and in POD1. Pain score was assessed on POD1. To monitor pleural effusion and atelectasis chest radiography was performed routinely 1 day before operation and until POD5. In both groups a significant impairment was found in lung function parameters until on POD5. However, no significant difference in forced vital capacity and forced expiratory volume in 1 second were seen between groups. A significant decrease in partial pressure of arterial oxygen and an increase in shunt fraction values were observed on POD1 in both groups, but no statistical difference was found when the groups were compared. Pleural effusion and atelectasis until on POD5 were similar in both groups. There were no statistical differences in pain score, duration of mechanical ventilation and postoperative hospital stay between groups. Subxyphoid insertion of pleural drain provides similar effects to

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.)

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.

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.

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

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.

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...

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.

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.

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...

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.

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.

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 : ...

A pleural vacuum relief device for pleural drain unit use in the hyperbaric environment.

Science.gov (United States)

Gelsomino, Marco; Tsouras, Theo; Millar, Ian; Fock, Andrew

2017-09-01

When a standard water-seal pleural drain unit (PDU) is used under hyperbaric conditions there are scenarios where excessive negative intrapleural pressure (IPP) and/or fluid reflux can be induced, risking significant morbidity. We developed and tested a pleural vacuum relief (PVR) device which automatically manages these risks, whilst allowing more rapid hyperbaric pressure change rates. The custom-made PVR device consists of a one-way pressure relief valve connected in line with a sterile micro filter selected for its specific flow capacity. The PVR device is designed for connection to the patient side sampling port of a PDU system, allowing inflow of ambient air whenever negative pressure is present, creating a small, controlled air leak which prevents excessive negative pressure. The hyperbaric performance of a Pleur-Evac A-6000 intercostal drain was assessed with and without this added device by measuring simulated IPP with an electronic pressure monitor connected at the patient end of the PDU. IPP readings were taken at 10, 15, 20 and 30 cmH₂O of suction (set on the drain unit) at compression rates of 10, 30, 60, 80, 90 and 180 kPa·min⁻¹ to a pressure of 280 kPa. At any compression rate of > 10 kPa·min⁻¹, the negative IPP generated by the Pleur-Evac A-6000 alone was excessive and resulted in back flow through the PDU water seal. By adding the PVR device, the generated negative IPP remains within a clinically acceptable range, allowing compression rates of at least 30 kPa·min⁻¹ with suction settings up to -20 cmH₂O during all phases of hyperbaric treatment. The PDU PVR device we have developed works well, minimising attendant workload and automatically avoiding the excessive negative IPPs that can otherwise occur. This device should only be used with suction.

Biogenic Carbon on Mars: A Subsurface Chauvinistic Viewpoint

Science.gov (United States)

Onstott, T. C.; Lau, C. Y. M.; Magnabosco, C.; Harris, R.; Chen, Y.; Slater, G.; Sherwood Lollar, B.; Kieft, T. L.; van Heerden, E.; Borgonie, G.; Dong, H.

2015-12-01

A review of 150 publications on the subsurface microbiology of the continental subsurface provides ~1,400 measurements of cellular abundances down to 4,800 meter depth. These data suggest that the continental subsurface biomass is comprised of ~1016-17 grams of carbon, which is higher than the most recent estimates of ~1015 grams of carbon (1 Gt) for the marine deep biosphere. If life developed early in Martian history and Mars sustained an active hydrological cycle during its first 500 million years, then is it possible that Mars could have developed a subsurface biomass of comparable size to that of Earth? Such a biomass would comprise a much larger fraction of the total known Martian carbon budget than does the subsurface biomass on Earth. More importantly could a remnant of this subsurface biosphere survive to the present day? To determine how sustainable subsurface life could be in isolation from the surface we have been studying subsurface fracture fluids from the Precambrian Shields in South Africa and Canada. In these environments the energetically efficient and deeply rooted acetyl-CoA pathway for carbon fixation plays a central role for chemolithoautotrophic primary producers that form the base of the biomass pyramid. These primary producers appear to be sustained indefinitely by H2 generated through serpentinization and radiolytic reactions. Carbon isotope data suggest that in some subsurface locations a much larger population of secondary consumers are sustained by the primary production of biogenic CH4 from a much smaller population of methanogens. These inverted biomass and energy pyramids sustained by the cycling of CH4 could have been and could still be active on Mars. The C and H isotopic signatures of Martian CH4 remain key tools in identifying potential signatures of an extant Martian biosphere. Based upon our results to date cavity ring-down spectroscopic technologies provide an option for making these measurements on future rover missions.

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)

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.

Subsurface contaminants focus area

International Nuclear Information System (INIS)

1996-08-01

The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites

Subsurface contaminants focus area

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-08-01

The US Department of Enregy (DOE) Subsurface Contaminants Focus Area is developing technologies to address environmental problems associated with hazardous and radioactive contaminants in soil and groundwater that exist throughout the DOE complex, including radionuclides, heavy metals; and dense non-aqueous phase liquids (DNAPLs). More than 5,700 known DOE groundwater plumes have contaminated over 600 billion gallons of water and 200 million cubic meters of soil. Migration of these plumes threatens local and regional water sources, and in some cases has already adversely impacted off-site rsources. In addition, the Subsurface Contaminants Focus Area is responsible for supplying technologies for the remediation of numerous landfills at DOE facilities. These landfills are estimated to contain over 3 million cubic meters of radioactive and hazardous buried Technology developed within this specialty area will provide efective methods to contain contaminant plumes and new or alternative technologies for development of in situ technologies to minimize waste disposal costs and potential worker exposure by treating plumes in place. While addressing contaminant plumes emanating from DOE landfills, the Subsurface Contaminants Focus Area is also working to develop new or alternative technologies for the in situ stabilization, and nonintrusive characterization of these disposal sites.

Subsurface Science Program Bibliography, 1985--1992

International Nuclear Information System (INIS)

1992-08-01

The Subsurface Science Program sponsors long-term basic research on (1) the fundamental physical, chemical, and biological mechanisms that control the reactivity, mobilization, stability, and transport of chemical mixtures in subsoils and ground water; (2) hydrogeology, including the hydraulic, microbiological, and geochemical properties of the vadose and saturated zones that control contaminant mobility and stability, including predictive modeling of coupled hydraulic-geochemical-microbial processes; and (3) the microbiology of deep sediments and ground water. TWs research, focused as it is on the natural subsurface environments that are most significantly affected by the more than 40 years of waste generation and disposal at DOE sites, is making important contributions to cleanup of DOE sites. Past DOE waste-disposal practices have resulted in subsurface contamination at DOE sites by unique combinations of radioactive materials and organic and inorganic chemicals (including heavy metals), which make site cleanup particularly difficult. The long- term (10- to 30-year) goal of the Subsurface Science Program is to provide a foundation of fundamental knowledge that can be used to reduce environmental risks and to provide a sound scientific basis for cost-effective cleanup strategies. The Subsurface Science Program is organized into nine interdisciplinary subprograms, or areas of basic research emphasis. The subprograms currently cover the areas of Co-Contaminant Chemistry, Colloids/Biocolloids, Multiphase Fluid Flow, Biodegradation/ Microbial Physiology, Deep Microbiology, Coupled Processes, Field-Scale (Natural Heterogeneity and Scale), and Environmental Science Research Center

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.

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).

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.

Subsurface probing

International Nuclear Information System (INIS)

Lytle, R.J.

1978-01-01

Imaging techniques that can be used to translate seismic and electromagnetic wave signals into visual representation are briefly discussed. The application of these techniques is illustrated on the example of determining the subsurface structure of a proposed power plant. Imaging makes the wave signals intelligible to the non-geologists. R and D work needed in this area are tabulated

Continuous gravity measurements reveal a low-density lava lake at Kīlauea Volcano, Hawai‘i

Science.gov (United States)

Carbone, Daniele; Poland, Michael P.; Patrick, Matthew R.; Orr, Tim R.

2013-01-01

On 5 March 2011, the lava lake within the summit eruptive vent at Kīlauea Volcano, Hawai‘i, began to drain as magma withdrew to feed a dike intrusion and fissure eruption on the volcanoʼs east rift zone. The draining was monitored by a variety of continuous geological and geophysical measurements, including deformation, thermal and visual imagery, and gravity. Over the first ∼14 hours of the draining, the ground near the eruptive vent subsided by about 0.15 m, gravity dropped by more than 100 μGal, and the lava lake retreated by over 120 m. We used GPS data to correct the gravity signal for the effects of subsurface mass loss and vertical deformation in order to isolate the change in gravity due to draining of the lava lake alone. Using a model of the eruptive vent geometry based on visual observations and the lava level over time determined from thermal camera data, we calculated the best-fit lava density to the observed gravity decrease — to our knowledge, the first geophysical determination of the density of a lava lake anywhere in the world. Our result, 950 +/- 300 kg m-3, suggests a lava density less than that of water and indicates that Kīlaueaʼs lava lake is gas-rich, which can explain why rockfalls that impact the lake trigger small explosions. Knowledge of such a fundamental material property as density is also critical to investigations of lava-lake convection and degassing and can inform calculations of pressure change in the subsurface magma plumbing system.

Organic acid derivatization techniques applied to petroleum hydrocarbon transformations in subsurface environments

International Nuclear Information System (INIS)

Barcelona, M.J.; Lu, J.; Tomczak, D.M.

1995-01-01

Evidence for the natural microbial remediation of subsurface fuel contamination situations should include identification and analysis of transformation or degradation products. In this way, a mass balance between fuel constituents and end products may be approached to monitor cleanup progress. Application of advanced organic acid metabolite derivatization techniques to several know sites of organic compounds and fuel mixture contamination provide valuable information on the pathways and progress of microbial transformation. Good correlation between observed metabolites and transformation pathways of aromatic fuel constituents were observed at the sites

Subsurface transport program: Research summary

International Nuclear Information System (INIS)

1987-01-01

DOE's research program in subsurface transport is designed to provide a base of fundamental scientific information so that the geochemical, hydrological, and biological mechanisms that contribute to the transport and long term fate of energy related contaminants in subsurface ecosystems can be understood. Understanding the physical and chemical mechanisms that control the transport of single and co-contaminants is the underlying concern of the program. Particular attention is given to interdisciplinary research and to geosphere-biosphere interactions. The scientific results of the program will contribute to resolving Departmental questions related to the disposal of energy-producing and defense wastes. The background papers prepared in support of this document contain additional information on the relevance of the research in the long term to energy-producing technologies. Detailed scientific plans and other research documents are available for high priority research areas, for example, in subsurface transport of organic chemicals and mixtures and in the microbiology of deep aquifers. 5 figs., 1 tab

Data inversion in coupled subsurface flow and geomechanics models

International Nuclear Information System (INIS)

Iglesias, Marco A; McLaughlin, Dennis

2012-01-01

We present an inverse modeling approach to estimate petrophysical and elastic properties of the subsurface. The aim is to use the fully coupled geomechanics-flow model of Girault et al (2011 Math. Models Methods Appl. Sci. 21 169–213) to jointly invert surface deformation and pressure data from wells. We use a functional-analytic framework to construct a forward operator (parameter-to-output map) that arises from the geomechanics-flow model of Girault et al. Then, we follow a deterministic approach to pose the inverse problem of finding parameter estimates from measurements of the output of the forward operator. We prove that this inverse problem is ill-posed in the sense of stability. The inverse problem is then regularized with the implementation of the Newton-conjugate gradient (CG) algorithm of Hanke (1997 Numer. Funct. Anal. Optim. 18 18–971). For a consistent application of the Newton-CG scheme, we establish the differentiability of the forward map and characterize the adjoint of its linearization. We provide assumptions under which the theory of Hanke ensures convergence and regularizing properties of the Newton-CG scheme. These properties are verified in our numerical experiments. In addition, our synthetic experiments display the capabilities of the proposed inverse approach to estimate parameters of the subsurface by means of data inversion. In particular, the added value of measurements of surface deformation in the estimation of absolute permeability is quantified with respect to the standard history matching approach of inverting production data with flow models. The proposed methodology can be potentially used to invert satellite geodetic data (e.g. InSAR and GPS) in combination with production data for optimal monitoring and characterization of the subsurface. (paper)

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.

MSTS - Multiphase Subsurface Transport Simulator theory manual

International Nuclear Information System (INIS)

White, M.D.; Nichols, W.E.

1993-05-01

The US Department of Energy, through the Yucca Mountain Site Characterization Project Office, has designated the Yucca Mountain site in Nevada for detailed study as the candidate US geologic repository for spent nuclear fuel and high-level radioactive waste. Site characterization will determine the suitability of the Yucca Mountain site for the potential waste repository. If the site is determined suitable, subsequent studies and characterization will be conducted to obtain authorization from the Nuclear Regulatory Commission to construct the potential waste repository. A principal component of the characterization and licensing processes involves numerically predicting the thermal and hydrologic response of the subsurface environment of the Yucca Mountain site to the potential repository over a 10,000-year period. The thermal and hydrologic response of the subsurface environment to the repository is anticipated to include complex processes of countercurrent vapor and liquid migration, multiple-phase heat transfer, multiple-phase transport, and geochemical reactions. Numerical simulators based on mathematical descriptions of these subsurface phenomena are required to make numerical predictions of the thermal and hydrologic response of the Yucca Mountain subsurface environment The engineering simulator called the Multiphase Subsurface Transport Simulator (MSTS) was developed at the request of the Yucca Mountain Site Characterization Project Office to produce numerical predictions of subsurface flow and transport phenomena at the potential Yucca Mountain site. This document delineates the design architecture and describes the specific computational algorithms that compose MSTS. Details for using MSTS and sample problems are given in the open-quotes User's Guide and Referenceclose quotes companion document

Synthetic seismic monitoring using reverse-time migration and Kirchhoff migration for CO2 sequestration in Korea

Science.gov (United States)

Kim, W.; Kim, Y.; Min, D.; Oh, J.; Huh, C.; Kang, S.

2012-12-01

During last two decades, CO2 sequestration in the subsurface has been extensively studied and progressed as a direct tool to reduce CO2 emission. Commercial projects such as Sleipner, In Salah and Weyburn that inject more than one million tons of CO2 per year are operated actively as well as test projects such as Ketzin to study the behavior of CO2 and the monitoring techniques. Korea also began the CCS (CO2 capture and storage) project. One of the prospects for CO2 sequestration in Korea is the southwestern continental margin of Ulleung basin. To monitor the behavior of CO2 underground for the evaluation of stability and safety, several geophysical monitoring techniques should be applied. Among various geophysical monitoring techniques, seismic survey is considered as the most effective tool. To verify CO2 migration in the subsurface more effectively, seismic numerical simulation is an essential process. Furthermore, the efficiency of the seismic migration techniques should be investigated for various cases because numerical seismic simulation and migration test help us accurately interpret CO2 migration. In this study, we apply the reverse-time migration and Kirchhoff migration to synthetic seismic monitoring data generated for the simplified model based on the geological structures of Ulleung basin in Korea. Synthetic seismic monitoring data are generated for various cases of CO2 migration in the subsurface. From the seismic migration images, we can investigate CO2 diffusion patterns indirectly. From seismic monitoring simulation, it is noted that while the reverse-time migration generates clear subsurface images when subsurface structures are steeply dipping, Kirchhoff migration has an advantage in imaging horizontal-layered structures such as depositional sediments appearing in the continental shelf. The reverse-time migration and Kirchhoff migration present reliable subsurface images for the potential site characterized by stratigraphical traps. In case of

Immunological techniques as tools to characterize the subsurface microbial community at a trichloroethylene contaminated site

Energy Technology Data Exchange (ETDEWEB)

Fliermans, C.B.; Dougherty, J.M.; Franck, M.M.; McKinzey, P.C.; Hazen, T.C.

1992-01-01

Effective in situ bioremediation strategies require an understanding of the effects pollutants and remediation techniques have on subsurface microbial communities. Therefore, detailed characterization of a site's microbial communities is important. Subsurface sediment borings and water samples were collected from a trichloroethylene (TCE) contaminated site, before and after horizontal well in situ air stripping and bioventing, as well as during methane injection for stimulation of methane-utilizing microorganisms. Subsamples were processed for heterotrophic plate counts, acridine orange direct counts (AODC), community diversity, direct fluorescent antibodies (DFA) enumeration for several nitrogen-transforming bacteria, and Biolog [reg sign] evaluation of enzyme activity in collected water samples. Plate counts were higher in near-surface depths than in the vadose zone sediment samples. During the in situ air stripping and bioventing, counts increased at or near the saturated zone, remained elevated throughout the aquifer, but did not change significantly after the air stripping. Sporadic increases in plate counts at different depths as well as increased diversity appeared to be linked to differing lithologies. AODCs were orders of magnitude higher than plate counts and remained relatively constant with depth except for slight increases near the surface depths and the capillary fringe. Nitrogen-transforming bacteria, as measured by serospecific DFA, were greatly affected both by the in situ air stripping and the methane injection. Biolog[reg sign] activity appeared to increase with subsurface stimulation both by air and methane. The complexity of subsurface systems makes the use of selective monitoring tools imperative.

Immunological techniques as tools to characterize the subsurface microbial community at a trichloroethylene contaminated site

Energy Technology Data Exchange (ETDEWEB)

Fliermans, C.B.; Dougherty, J.M.; Franck, M.M.; McKinzey, P.C.; Hazen, T.C.

1992-12-31

Effective in situ bioremediation strategies require an understanding of the effects pollutants and remediation techniques have on subsurface microbial communities. Therefore, detailed characterization of a site`s microbial communities is important. Subsurface sediment borings and water samples were collected from a trichloroethylene (TCE) contaminated site, before and after horizontal well in situ air stripping and bioventing, as well as during methane injection for stimulation of methane-utilizing microorganisms. Subsamples were processed for heterotrophic plate counts, acridine orange direct counts (AODC), community diversity, direct fluorescent antibodies (DFA) enumeration for several nitrogen-transforming bacteria, and Biolog {reg_sign} evaluation of enzyme activity in collected water samples. Plate counts were higher in near-surface depths than in the vadose zone sediment samples. During the in situ air stripping and bioventing, counts increased at or near the saturated zone, remained elevated throughout the aquifer, but did not change significantly after the air stripping. Sporadic increases in plate counts at different depths as well as increased diversity appeared to be linked to differing lithologies. AODCs were orders of magnitude higher than plate counts and remained relatively constant with depth except for slight increases near the surface depths and the capillary fringe. Nitrogen-transforming bacteria, as measured by serospecific DFA, were greatly affected both by the in situ air stripping and the methane injection. Biolog{reg_sign} activity appeared to increase with subsurface stimulation both by air and methane. The complexity of subsurface systems makes the use of selective monitoring tools imperative.

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.

Subsurface Fire Hazards Technical Report

International Nuclear Information System (INIS)

Logan, R.C.

1999-01-01

The results from this report are preliminary and cannot be used as input into documents supporting procurement, fabrication, or construction. This technical report identifies fire hazards and proposes their mitigation for the subsurface repository fire protection system. The proposed mitigation establishes the minimum level of fire protection to meet NRC regulations, DOE fire protection orders, that ensure fire containment, adequate life safety provisions, and minimize property loss. Equipment requiring automatic fire suppression systems is identified. The subsurface fire hazards that are identified can be adequately mitigated

Field application of farmstead runoff to vegetated filter strips: surface and subsurface water quality assessment.

Science.gov (United States)

Larson, Rebecca A; Safferman, Steven I

2012-01-01

Farmstead runoff poses significant environmental impacts to ground and surface waters. Three vegetated filter strips were assessed for the treatment of dairy farmstead runoff at the soil surface and subsurface at 0.3- or 0. 46-m and 0. 76-m depths for numerous storm events. A medium-sized Michigan dairy was retrofitted with two filter strips on sandy loam soil and a third filter strip was implemented on a small Michigan dairy with sandy soil to collect and treat runoff from feed storage, manure storage, and other impervious farmstead areas. All filter strips were able to eliminate surface runoff via infiltration for all storm events over the duration of the study, eliminating pollutant contributions to surface water. Subsurface effluent was monitored to determine the contributing groundwater concentrations of numerous pollutants including chemical oxygen demand (COD), metals, and nitrates. Subsurface samples have an average reduction of COD concentrations of 20, 11, and 85% for the medium dairy Filter Strip 1 (FS1), medium dairy Filter Strip 2 (FS2), and the small Michigan dairy respectively, resulting in average subsurface concentrations of 355, 3960, and 718 mg L COD. Similar reductions were noted for ammonia and total Kjeldahl nitrogen (TKN) in the subsurface effluent. The small Michigan dairy was able to reduce the pollutant leachate concentrations of COD, TKN, and ammonia over a range of influent concentrations. Increased influent concentrations in the medium Michigan dairy filter strips resulted in an increase in COD, TKN, and ammonia concentrations in the leachate. Manganese was leached from the native soils at all filter strips as evidenced by the increase in manganese concentrations in the leachate. Nitrate concentrations were above standard drinking water limits (10 mg L), averaging subsurface concentrations of 11, 45, and 25 mg L NO-N for FS1, FS2, and the small Michigan dairy, respectively. Copyright © by the American Society of Agronomy, Crop Science

Subsurface barrier verification technologies, informal report

International Nuclear Information System (INIS)

Heiser, J.H.

1994-06-01

One of the more promising remediation options available to the DOE waste management community is subsurface barriers. Some of the uses of subsurface barriers include surrounding and/or containing buried waste, as secondary confinement of underground storage tanks, to direct or contain subsurface contaminant plumes and to restrict remediation methods, such as vacuum extraction, to a limited area. To be most effective the barriers should be continuous and depending on use, have few or no breaches. A breach may be formed through numerous pathways including: discontinuous grout application, from joints between panels and from cracking due to grout curing or wet-dry cycling. The ability to verify barrier integrity is valuable to the DOE, EPA, and commercial sector and will be required to gain full public acceptance of subsurface barriers as either primary or secondary confinement at waste sites. It is recognized that no suitable method exists for the verification of an emplaced barrier's integrity. The large size and deep placement of subsurface barriers makes detection of leaks challenging. This becomes magnified if the permissible leakage from the site is low. Detection of small cracks (fractions of an inch) at depths of 100 feet or more has not been possible using existing surface geophysical techniques. Compounding the problem of locating flaws in a barrier is the fact that no placement technology can guarantee the completeness or integrity of the emplaced barrier. This report summarizes several commonly used or promising technologies that have been or may be applied to in-situ barrier continuity verification

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.

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.

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

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.

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

U-tube based near-surface environmental monitoring in the Shenhua carbon dioxide capture and storage (CCS) project.

Science.gov (United States)

Li, Qi; Song, Ranran; Shi, Hui; Ma, Jianli; Liu, Xuehao; Li, Xiaochun

2018-04-01

The CO 2 injected into deep formations during implementation of carbon dioxide (CO 2 ) capture and storage (CCS) technology may leak and migrate into shallow aquifers or ground surfaces through a variety of pathways over a long period. The leaked CO 2 can threaten shallow environments as well as human health. Therefore, almost all monitoring programs for CCS projects around the world contain near-surface monitoring. This paper presents a U-tube based near-surface monitoring technology focusing on its first application in the Shenhua CCS demonstration project, located in the Ordos Basin, Inner Mongolia, China. First, background information on the site monitoring program of the Shenhua CCS demonstration project was provided. Then, the principle of fluid sampling and the monitoring methods were summarized for the U-tube sampler system, and the monitoring data were analyzed in detail. The U-tube based monitoring results showed that the U-tube sampler system is accurate, flexible, and representative of the subsurface fluid sampling process. The monitoring indicators for the subsurface water and soil gas at the Shenhua CCS site indicate good stratification characteristics. The concentration level of each monitoring indicator decreases with increasing depth. Finally, the significance of this near-surface environmental monitoring technology for CO 2 leakage assessments was preliminarily confirmed at the Shenhua CCS site. The application potential of the U-tube based monitoring technology was also demonstrated during the subsurface environmental monitoring of other CCS projects.

Subsurface quality assurance practices

International Nuclear Information System (INIS)

1987-08-01

This report addresses only the concept of applying Nuclear Quality Assurance (NQA) practices to repository shaft and subsurface design and construction; how NQA will be applied; and the level of detail required in the documentation for construction of a shaft and subsurface repository in contrast to the level of detail required in the documentation for construction of a traditional mine. This study determined that NQA practices are viable, attainable, as well as required. The study identified the appropriate NQA criteria and the repository's major structures, systems, items, and activities to which the criteria are applicable. A QA plan, for design and construction, and a list of documentation, for construction, are presented. 7 refs., 1 fig., 18 tabs

Characterization of accumulated precipitates during subsurface iron removal

International Nuclear Information System (INIS)

Halem, Doris van; Vet, Weren de; Verberk, Jasper; Amy, Gary; Dijk, Hans van

2011-01-01

Research highlights: → Accumulated iron was not found to clog the well or aquifer after 12 years of subsurface iron removal. → 56-100% of accumulated iron hydroxides were found to be crystalline. → Subsurface iron removal favoured certain soil layers, either due to hydraulics or mineralogy. → Other groundwater constituents, such as manganese and arsenic were found to co-accumulate with iron. - Abstract: The principle of subsurface iron removal for drinking water supply is that aerated water is periodically injected into the aquifer through a tube well. On its way into the aquifer, the injected O 2 -rich water oxidizes adsorbed Fe 2+ , creating a subsurface oxidation zone. When groundwater abstraction is resumed, the soluble Fe 2+ is adsorbed and water with reduced Fe concentrations is abstracted for multiple volumes of the injection water. In this article, Fe accumulation deposits in the aquifer near subsurface treatment wells were identified and characterized to assess the sustainability of subsurface iron removal regarding clogging of the aquifer and the potential co-accumulation of other groundwater constituents, such as As. Chemical extraction of soil samples, with Acid-Oxalate and HNO 3 , showed that Fe had accumulated at specific depths near subsurface iron removal wells after 12 years of operation. Whether it was due to preferred flow paths or geochemical mineralogy conditions; subsurface iron removal clearly favoured certain soil layers. The total Fe content increased between 11.5 and 390.8 mmol/kg ds in the affected soil layers, and the accumulated Fe was found to be 56-100% crystalline. These results suggest that precipitated amorphous Fe hydroxides have transformed to Fe hydroxides of higher crystallinity. These crystalline, compact Fe hydroxides have not noticeably clogged the investigated well and/or aquifer between 1996 and 2008. The subsurface iron removal wells even need less frequent rehabilitation, as drawdown increases more slowly than in

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

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.

Drawing the subsurface : an integrative design approach

NARCIS (Netherlands)

Hooimeijer, F.L.; Lafleur, F.; Trinh, T.T.; Gogu, Constantin Radu; Campbell, Diarmad; de Beer, Johannes

2017-01-01

The sub-surface, with its man-made and natural components, plays an important, if not crucial, role in the urban climate and global energy transition. On the one hand, the sub-surface is associated with a variety of challenges such as subsidence, pollution, damage to infrastructure and shortages of

Improving the biodegradative capacity of subsurface bacteria

International Nuclear Information System (INIS)

Romine, M.F.; Brockman, F.J.

1993-04-01

The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates

Advances in interpretation of subsurface processes with time-lapse electrical imaging

Science.gov (United States)

Singha, Kaminit; Day-Lewis, Frederick D.; Johnson, Tim B.; Slater, Lee D.

2015-01-01

Electrical geophysical methods, including electrical resistivity, time-domain induced polarization, and complex resistivity, have become commonly used to image the near subsurface. Here, we outline their utility for time-lapse imaging of hydrological, geochemical, and biogeochemical processes, focusing on new instrumentation, processing, and analysis techniques specific to monitoring. We review data collection procedures, parameters measured, and petrophysical relationships and then outline the state of the science with respect to inversion methodologies, including coupled inversion. We conclude by highlighting recent research focused on innovative applications of time-lapse imaging in hydrology, biology, ecology, and geochemistry, among other areas of interest.

Contaminant geochemistry. Interactions and transport in the subsurface environment

Energy Technology Data Exchange (ETDEWEB)

Berkowitz, Brian; Dror, Ishai; Yaron, Bruno [Weizmann Institute of Science, Rehovot (Israel). Dept. of Environmental Sciences and Energy Research

2008-07-01

This book combines earth science, subsurface hydrology and environmental geochemistry, providing a comprehensive background for specialists interested in the protection and sustainable management of the subsurface environment. The reader is introduced to the chemistry of contaminants, which usually disturb the natural equilibrium in the subsurface as a result of human activity. The major focus of the book is on contaminant reactions in soil solutions, groundwater and porous media solid phases, accounting for their persistence and transformation in the subsurface, as they are transported from the land surface into groundwater. Discussions on selected case studies are provided. (orig.)

Differential Muon Tomography to Continuously Monitor Changes in the Composition of Subsurface Fluids

Science.gov (United States)

Coleman, Max; Kudryavtsev, Vitaly A.; Spooner, Neil J.; Fung, Cora; Gluyas, John

2013-01-01

Muon tomography has been used to seek hidden chambers in Egyptian pyramids and image subsurface features in volcanoes. It seemed likely that it could be used to image injected, supercritical carbon dioxide as it is emplaced in porous geological structures being used for carbon sequestration, and also to check on subsequent leakage. It should work equally well in any other application where there are two fluids of different densities, such as water and oil, or carbon dioxide and heavy oil in oil reservoirs. Continuous monitoring of movement of oil and/or flood fluid during enhanced oil recovery activities for managing injection is important for economic reasons. Checking on leakage for geological carbon storage is essential both for safety and for economic purposes. Current technology (for example, repeat 3D seismic surveys) is expensive and episodic. Muons are generated by high- energy cosmic rays resulting from supernova explosions, and interact with gas molecules in the atmosphere. This innovation has produced a theoretical model of muon attenuation in the thickness of rock above and within a typical sandstone reservoir at a depth of between 1.00 and 1.25 km. Because this first simulation was focused on carbon sequestration, the innovators chose depths sufficient for the pressure there to ensure that the carbon dioxide would be supercritical. This innovation demonstrates for the first time the feasibility of using the natural cosmic-ray muon flux to generate continuous tomographic images of carbon dioxide in a storage site. The muon flux is attenuated to an extent dependent on, amongst other things, the density of the materials through which it passes. The density of supercritical carbon dioxide is only three quarters that of the brine in the reservoir that it displaces. The first realistic simulations indicate that changes as small as 0.4% in the storage site bulk density could be detected (equivalent to 7% of the porosity, in this specific case). The initial

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...

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.

Extracting subsurface fingerprints using optical coherence tomography

CSIR Research Space (South Africa)

Akhoury, SS

2015-02-01

Full Text Available Subsurface Fingerprints using Optical Coherence Tomography Sharat Saurabh Akhoury, Luke Nicholas Darlow Modelling and Digital Science, Council for Scientific and Industrial Research, Pretoria, South Africa Abstract Physiologists have found... approach to extract the subsurface fingerprint representation using a high-resolution imaging technology known as Optical Coherence Tomography (OCT). ...

Pleurotomy with subxyphoid pleural drain affords similar effects to pleural integrity in pulmonary function after off-pump coronary artery bypass graft

Directory of Open Access Journals (Sweden)

Guizilini Solange

2012-01-01

Full Text Available Abstract Background Exacerbation of pulmonary dysfunction has been reported in patients receiving a pleural drain inserted through the intercostal space in comparison to patients with an intact pleura undergoing coronary artery bypass grafting (CABG. Evidence suggests that shifting the site of pleural drain insertion to the subxyphoid position minimizes chest wall trauma and preserves respiratory function in the early postoperative period. The aim of this study was to compare the pulmonary function parameters, clinical outcomes, and pain score between patients undergoing pleurotomy with pleural drain placed in the subxyphoid position and patients with intact pleural cavity after off-pump CABG (OPCAB using left internal thoracic artery (LITA. Methods Seventy-one patients were allocated into two groups: I (n = 38 open left pleural cavity and pleural drain inserted in the subxyphoid position; II (n = 33 intact pleural cavity. Pulmonary function tests and clinical parameters were recorded preoperatively and on postoperative days (POD 1, 3 and 5. Arterial blood gas analysis and shunt fraction were evaluated preoperatively and in POD1. Pain score was assessed on POD1. To monitor pleural effusion and atelectasis chest radiography was performed routinely 1 day before operation and until POD5. Results In both groups a significant impairment was found in lung function parameters until on POD5. However, no significant difference in forced vital capacity and forced expiratory volume in 1 second were seen between groups. A significant decrease in partial pressure of arterial oxygen and an increase in shunt fraction values were observed on POD1 in both groups, but no statistical difference was found when the groups were compared. Pleural effusion and atelectasis until on POD5 were similar in both groups. There were no statistical differences in pain score, duration of mechanical ventilation and postoperative hospital stay between groups. Conclusion Subxyphoid

Defining the Post-Machined Sub-surface in Austenitic Stainless Steels

Science.gov (United States)

Srinivasan, N.; Sunil Kumar, B.; Kain, V.; Birbilis, N.; Joshi, S. S.; Sivaprasad, P. V.; Chai, G.; Durgaprasad, A.; Bhattacharya, S.; Samajdar, I.

2018-06-01

Austenitic stainless steels grades, with differences in chemistry, stacking fault energy, and thermal conductivity, were subjected to vertical milling. Anodic potentiodynamic polarization was able to differentiate (with machining speed/strain rate) between different post-machined sub-surfaces in SS 316L and Alloy A (a Cu containing austenitic stainless steel: Sanicroe 28™), but not in SS 304L. However, such differences (in the post-machined sub-surfaces) were revealed in surface roughness, sub-surface residual stresses and misorientations, and in the relative presence of sub-surface Cr2O3 films. It was shown, quantitatively, that higher machining speed reduced surface roughness and also reduced the effective depths of the affected sub-surface layers. A qualitative explanation on the sub-surface microstructural developments was provided based on the temperature-dependent thermal conductivity values. The results herein represent a mechanistic understanding to rationalize the corrosion performance of widely adopted engineering alloys.

Defining the Post-Machined Sub-surface in Austenitic Stainless Steels

Science.gov (United States)

Srinivasan, N.; Sunil Kumar, B.; Kain, V.; Birbilis, N.; Joshi, S. S.; Sivaprasad, P. V.; Chai, G.; Durgaprasad, A.; Bhattacharya, S.; Samajdar, I.

2018-04-01

Austenitic stainless steels grades, with differences in chemistry, stacking fault energy, and thermal conductivity, were subjected to vertical milling. Anodic potentiodynamic polarization was able to differentiate (with machining speed/strain rate) between different post-machined sub-surfaces in SS 316L and Alloy A (a Cu containing austenitic stainless steel: Sanicroe 28™), but not in SS 304L. However, such differences (in the post-machined sub-surfaces) were revealed in surface roughness, sub-surface residual stresses and misorientations, and in the relative presence of sub-surface Cr2O3 films. It was shown, quantitatively, that higher machining speed reduced surface roughness and also reduced the effective depths of the affected sub-surface layers. A qualitative explanation on the sub-surface microstructural developments was provided based on the temperature-dependent thermal conductivity values. The results herein represent a mechanistic understanding to rationalize the corrosion performance of widely adopted engineering alloys.

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.

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.

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.

Characterization of accumulated precipitates during subsurface iron removal

KAUST Repository

Van Halem, Doris

2011-01-01

The principle of subsurface iron removal for drinking water supply is that aerated water is periodically injected into the aquifer through a tube well. On its way into the aquifer, the injected O2-rich water oxidizes adsorbed Fe 2+, creating a subsurface oxidation zone. When groundwater abstraction is resumed, the soluble Fe 2+ is adsorbed and water with reduced Fe concentrations is abstracted for multiple volumes of the injection water. In this article, Fe accumulation deposits in the aquifer near subsurface treatment wells were identified and characterized to assess the sustainability of subsurface iron removal regarding clogging of the aquifer and the potential co-accumulation of other groundwater constituents, such as As. Chemical extraction of soil samples, with Acid-Oxalate and HNO3, showed that Fe had accumulated at specific depths near subsurface iron removal wells after 12 years of operation. Whether it was due to preferred flow paths or geochemical mineralogy conditions; subsurface iron removal clearly favoured certain soil layers. The total Fe content increased between 11.5 and 390.8 mmol/kg ds in the affected soil layers, and the accumulated Fe was found to be 56-100% crystalline. These results suggest that precipitated amorphous Fe hydroxides have transformed to Fe hydroxides of higher crystallinity. These crystalline, compact Fe hydroxides have not noticeably clogged the investigated well and/or aquifer between 1996 and 2008. The subsurface iron removal wells even need less frequent rehabilitation, as drawdown increases more slowly than in normal production wells. Other groundwater constituents, such as Mn, As and Sr were found to co-accumulate with Fe. Acid extraction and ESEM-EDX showed that Ca occurred together with Fe and by X-ray Powder Diffraction it was identified as calcite. © 2010 Elsevier Ltd. All rights reserved.

The Lusi eruption site: insights from surface and subsurface investigations

Science.gov (United States)

Mazzini, A.

2017-12-01

The Indonesian Lusi eruption has been spewing boiling water, gas, and sediments since the 29th of May 2006. Initially, numerous aligned eruptions sites appeared along the Watukosek fault system (WFS) that was reactivated after the Yogyakarta earthquake occurring the 27th of May in the Java Island. Within weeks several villages were submerged by boiling mud. The most prominent eruption site was named Lusi. To date Lusi is still active and an area of 7 km2is covered by mud. Since its birth Lusi erupted with a pulsating behaviour. In the framework of the ERC grant "Lusi Lab" we conducted several years of monitoring and regional investigations coupling surface sampling and subsurface imaging in the region around Lusi. Ambient noise tomography studies, obtained with a local network of 31 stations, revealed for the first time subsurface images of the Lusi region and the adjacent Arjuno-Welirang (AW) volcanic complex. Results show that below the AW volcanic complex are present 5km deep magma chambers that are connected, through a defined corridor, with the roots of the Lusi eruption site. The Lusi subsurface shows the presence of a defined vertical hydrothermal plume that extends to at least 5km. Chemical analyses of the seeping fluids sampled from 1) the Lusi plume (using a specifically designed drone), 2) the region around Lusi, and 3) the fumaroles and the hydro thermal springs of AW, revealed striking similarities. More specifically a mantellic signature of the Lusi fluids confirms the scenario that Lusi represents a magmatic-driven hydrothermal system hosted in sedimentary basin. Seismic profiles interpretation, surface mapping, and fluid sampling show that the WFS, connecting AW and extending towards the NE of Java, acted as a preferential pathway for the igneous intrusion and fluids migration towards the subsurface. Petrography and dating of the clasts erupted at Lusi record high temperatures and indicate that the roots of the active conduit extend to at least 5km

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).

Evaluation on the Efficiency of Subsurface Drainage in Chiu-Fen Landslide at Northern Taiwan

Science.gov (United States)

Ying, L. Y.; Lin, D. G.

2015-12-01

For administrative district, the Chiu-Fen landslide is situated at northern Taiwan and comes within the jurisdiction of Ruei-Fang district, New Taipei City Government. Chiu-Fen village is a famous spot for sightseeing and tourism in Southeast Asia. In the last decade, for economic purpose, a vast area of slope land in Chiu-Fen area was reclaimed into business and commercial districts. However, due to the complicated geological and hydrological conditions, improper reclamation, and lack of appropriate soil and water conservation facilities, large scale landslides are frequently triggered by typhoon rainfall and causes damages to the transportation and residential building in the community. As a consequence, the government initiated a comprehensive field investigations and remediation plans to stabilize the landslide from 1997 and the remediation works were concentrated on subsurface drainages, namely the application of drainage well (a vertical shaft with multi-level horizontal drainage boreholes). To investigate the efficiency of drainage wells on the landslide, the A1-profile in the landslide which covers the drainage wells W2 and W4 was selected for a series of rainfall seepage and slope stability analyses. In addition, a 48-hrs design rainfall with return period of 25, 50 and 100 years based on the local meteorological data bank was adopted for the analyses. The numerical results indicate the factor safety FS of the three potential sliding surfaces within A1-profile are constantly keeping greater than one (FS > 1.0) and without decreasing with the elapsed time during rainfall. This implies that the subsurface drainage works can drain off the infiltrated rainwater from a high intensity and long duration rainfall and preserve the slope stability of landslides from deterioration. Finally, the efficiency of the drainage wells can be evaluated quantitatively in terms of the time-dependent factor of safety and the pore water pressure distribution on several potential

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.

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%.

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)

Contaminated environments in the subsurface and bioremediation: organic contaminants

OpenAIRE

Holliger, Christof; Gaspard, Sarra; Glod, Guy; Heijman, Cornelis; Schumacher, Wolfram; Schwarzenbach, René P.; Vazquez, Francisco

2017-01-01

Due to leakages, spills, improper disposal and accidents during transport, organic compounds have become subsurface contaminants that threaten important drinking water resources. One strategy to remediate such polluted subsurface environments is to make use of the degradative capacity of bacteria. It is often sufficient to supply the subsurface with nutrients such as nitrogen and phosphorus, and aerobic treatments are still dominating. However, anaerobic processes have advantages such as low ...

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)

Integrated Surface/subsurface flow modeling in PFLOTRAN

Energy Technology Data Exchange (ETDEWEB)

Painter, Scott L [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-10-01

Understanding soil water, groundwater, and shallow surface water dynamics as an integrated hydrological system is critical for understanding the Earth’s critical zone, the thin outer layer at our planet’s surface where vegetation, soil, rock, and gases interact to regulate the environment. Computational tools that take this view of soil moisture and shallow surface flows as a single integrated system are typically referred to as integrated surface/subsurface hydrology models. We extend the open-source, highly parallel, subsurface flow and reactive transport simulator PFLOTRAN to accommodate surface flows. In contrast to most previous implementations, we do not represent a distinct surface system. Instead, the vertical gradient in hydraulic head at the land surface is neglected, which allows the surface flow system to be eliminated and incorporated directly into the subsurface system. This tight coupling approach leads to a robust capability and also greatly simplifies implementation in existing subsurface simulators such as PFLOTRAN. Successful comparisons to independent numerical solutions build confidence in the approximation and implementation. Example simulations of the Walker Branch and East Fork Poplar Creek watersheds near Oak Ridge, Tennessee demonstrate the robustness of the approach in geometrically complex applications. The lack of a robust integrated surface/subsurface hydrology capability had been a barrier to PFLOTRAN’s use in critical zone studies. This work addresses that capability gap, thus enabling PFLOTRAN as a community platform for building integrated models of the critical zone.

Modular evaluation method for subsurface activities (MEMSA). A novel approach for integrating social acceptance in a permit decision-making process for subsurface activities

International Nuclear Information System (INIS)

Os, Herman W.A. van; Herber, Rien; Scholtens, Bert

2017-01-01

We investigate how the decision support system ‘Modular Evaluation Method Subsurface Activities’ (MEMSA) can help facilitate an informed decision-making process for permit applications of subsurface activities. To this end, we analyze the extent the MEMSA approach allows for a dialogue between stakeholders in a transparent manner. We use the exploration permit for the underground gas storage facility at the Pieterburen salt dome (Netherlands) as a case study. The results suggest that the MEMSA approach is flexible enough to adjust to changing conditions. Furthermore, MEMSA provides a novel way for identifying structural problems and possible solutions in permit decision-making processes for subsurface activities, on the basis of the sensitivity analysis of intermediate rankings. We suggest that the planned size of an activity should already be specified in the exploration phase, because this would allow for a more efficient use of the subsurface as a whole. We conclude that the host community should be involved to a greater extent and in an early phase of the permit decision-making process, for example, already during the initial analysis of the project area of a subsurface activity. We suggest that strategic national policy goals are to be re-evaluated on a regular basis, in the form of a strategic vision for the subsurface, to account for timing discrepancies between the realization of activities and policy deadlines, because this discrepancy can have a large impact on the necessity and therefore acceptance of a subsurface activity.

Modular evaluation method for subsurface activities (MEMSA). A novel approach for integrating social acceptance in a permit decision-making process for subsurface activities

Energy Technology Data Exchange (ETDEWEB)

Os, Herman W.A. van, E-mail: h.w.a.van.os@rug.nl [University of Groningen, Faculty of Mathematics and Natural Sciences, Geo-Energy, PO Box 800, 9700 AV Groningen (Netherlands); Herber, Rien, E-mail: rien.herber@rug.nl [University of Groningen, Faculty of Mathematics and Natural Sciences, Geo-Energy, PO Box 800, 9700 AV Groningen (Netherlands); Scholtens, Bert, E-mail: l.j.r.scholtens@rug.nl [University of Groningen, Faculty of Economics and Business, PO Box 800, 9700 AV Groningen (Netherlands)

2017-05-15

We investigate how the decision support system ‘Modular Evaluation Method Subsurface Activities’ (MEMSA) can help facilitate an informed decision-making process for permit applications of subsurface activities. To this end, we analyze the extent the MEMSA approach allows for a dialogue between stakeholders in a transparent manner. We use the exploration permit for the underground gas storage facility at the Pieterburen salt dome (Netherlands) as a case study. The results suggest that the MEMSA approach is flexible enough to adjust to changing conditions. Furthermore, MEMSA provides a novel way for identifying structural problems and possible solutions in permit decision-making processes for subsurface activities, on the basis of the sensitivity analysis of intermediate rankings. We suggest that the planned size of an activity should already be specified in the exploration phase, because this would allow for a more efficient use of the subsurface as a whole. We conclude that the host community should be involved to a greater extent and in an early phase of the permit decision-making process, for example, already during the initial analysis of the project area of a subsurface activity. We suggest that strategic national policy goals are to be re-evaluated on a regular basis, in the form of a strategic vision for the subsurface, to account for timing discrepancies between the realization of activities and policy deadlines, because this discrepancy can have a large impact on the necessity and therefore acceptance of a subsurface activity.

Engineering task plan for the vapor monitor installation into 241-C-103 tank

International Nuclear Information System (INIS)

Hertelendy, N.A.

1994-12-01

A vapor flow monitor is to be installed into the 241-C-103 tank's exhaust, just downstream of the HEPA filter. The flow monitor system includes the flow sensor, the baffle assembly, the signal conditioning and control electronics, and a chart recorder. The electronics package and the chart recorder are installed into a small, heated instrument cabinet that is mounted on the same steel pallet on which the flowmeter and the diffuser assembly is mounted. The flowmeter is connected to the HEPA filter with an unheated, un-insulated flex hose. An automatic drain, upstream of the flowmeter, is designed to automatically drain the condensate into an evaporating pan. The flowmeter is heated with a temperature controlled heater to avoid condensation

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.

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)

Electrode Cultivation and Interfacial Electron Transport in Subsurface Microorganisms

Science.gov (United States)

Karbelkar, A. A.; Jangir, Y.; Reese, B. K.; Wanger, G.; Anderson, C.; El-Naggar, M.; Amend, J.

2016-12-01

Continental subsurface environments can present significant energetic challenges to the resident microorganisms. While these environments are geologically diverse, potentially allowing energy harvesting by microorganisms that catalyze redox reactions, many of the abundant electron donors and acceptors are insoluble and therefore not directly bioavailable. Microbes can use extracellular electron transfer (EET) as a metabolic strategy to interact with redox active surfaces. This process can be mimicked on electrode surfaces and hence can lead to enrichment and quantification of subsurface microorganisms A primary bioelectrochemical enrichment with different oxidizing and reducing potentials set up in a single bioreactor was applied in situ to subsurface microorganisms residing in iron oxide rich deposits in the Sanford Underground Research Facility. Secondary enrichment revealed a plethora of classified and unclassified subsurface microbiota on both oxidizing and reducing potentials. From this enrichment, we have isolated a Gram-positive Bacillus along with Gram-negative Cupriavidus and Anaerospora strains (as electrode reducers) and Comamonas (as an electrode oxidizer). The Bacillus and Comamonas isolates were subjected to a detailed electrochemical characterization in half-reactors at anodic and cathodic potentials, respectively. An increase in cathodic current upon inoculation and cyclic voltammetry measurements confirm the hypothesis that Comamonas is capable of electron uptake from electrodes. In addition, measurements of Bacillus on anodes hint towards novel mechanisms that allow EET from Gram-positive bacteria. This study suggests that electrochemical approaches are well positioned to dissect such extracellular interactions that may be prevalent in the subsurface, while using physical electrodes to emulate the microhabitats, redox and geochemical gradients, and the spatially dependent interspecies interactions encountered in the subsurface. Electrochemical

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...

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...

30 CFR 250.119 - Will MMS approve subsurface gas storage?

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Will MMS approve subsurface gas storage? 250....119 Will MMS approve subsurface gas storage? The Regional Supervisor may authorize subsurface storage of gas on the OCS, on and off-lease, for later commercial benefit. To receive MMS approval you must...

Method of imaging the electrical conductivity distribution of a subsurface

Science.gov (United States)

Johnson, Timothy C.

2017-09-26

A method of imaging electrical conductivity distribution of a subsurface containing metallic structures with known locations and dimensions is disclosed. Current is injected into the subsurface to measure electrical potentials using multiple sets of electrodes, thus generating electrical resistivity tomography measurements. A numeric code is applied to simulate the measured potentials in the presence of the metallic structures. An inversion code is applied that utilizes the electrical resistivity tomography measurements and the simulated measured potentials to image the subsurface electrical conductivity distribution and remove effects of the subsurface metallic structures with known locations and dimensions.

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.

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)

Geochemical characterization of subsurface sediments in the Netherlands

NARCIS (Netherlands)

Huisman, D.J.

1998-01-01

Traditionally, the Netherlands' subsurface is mainly used to obtain good quality drinking and industrial waters from the different aquifers. Due to the lack of space on the surface, increasing environmental problems and demand for energy, the subsurface will be used increasingly for other

Electrical Subsurface Grounding Analysis

International Nuclear Information System (INIS)

J.M. Calle

2000-01-01

The purpose and objective of this analysis is to determine the present grounding requirements of the Exploratory Studies Facility (ESF) subsurface electrical system and to verify that the actual grounding system and devices satisfy the requirements

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

DEMONSTRATiON OF A SUBSURFACE CONTAINMENT SYSTEM FOR INSTALLATION AT DOE WASTE SITES

Energy Technology Data Exchange (ETDEWEB)

Thomas J. Crocker; Verna M. Carpenter

2003-05-21

Between 1952 and 1970, DOE buried mixed waste in pits and trenches that now have special cleanup needs. The disposal practices used decades ago left these landfills and other trenches, pits, and disposal sites filled with three million cubic meters of buried waste. This waste is becoming harmful to human safety and health. Today's cleanup and waste removal is time-consuming and expensive with some sites scheduled to complete cleanup by 2006 or later. An interim solution to the DOE buried waste problem is to encapsulate and hydraulically isolate the waste with a geomembrane barrier and monitor the performance of the barrier over its 50-yr lifetime. The installed containment barriers would isolate the buried waste and protect groundwater from pollutants until final remediations are completed. The DOE has awarded a contract to RAHCO International, Inc.; of Spokane, Washington; to design, develop, and test a novel subsurface barrier installation system, referred to as a Subsurface Containment System (SCS). The installed containment barrier consists of commercially available geomembrane materials that isolates the underground waste, similar to the way a swimming pools hold water, without disrupting hazardous material that was buried decades ago. The barrier protects soil and groundwater from contamination and effectively meets environmental cleanup standards while reducing risks, schedules, and costs. Constructing the subsurface containment barrier uses a combination of conventional and specialized equipment and a unique continuous construction process. This innovative equipment and construction method can construct a 1000-ft-long X 34-ft-wide X 30-ft-deep barrier at construction rates to 12 Wday (8 hr/day operation). Life cycle costs including RCRA cover and long-term monitoring range from approximately $380 to $590/cu yd of waste contained or $100 to $160/sq ft of placed barrier based upon the subsurface geology surrounding the waste. Project objectives for Phase

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)

Groundwater Salinity Simulation of a Subsurface Reservoir in Taiwan

Science.gov (United States)

Fang, H. T.

2015-12-01

The subsurface reservoir is located in Chi-Ken Basin, Pescadores (a group islands located at western part of Taiwan). There is no river in these remote islands and thus the freshwater supply is relied on the subsurface reservoir. The basin area of the subsurface reservoir is 2.14 km2 , discharge of groundwater is 1.27×106m3 , annual planning water supplies is 7.9×105m3 , which include for domestic agricultural usage. The annual average temperature is 23.3oC, average moisture is 80~85%, annual average rainfall is 913 mm, but ET rate is 1975mm. As there is no single river in the basin; the major recharge of groundwater is by infiltration. Chi-Ken reservoir is the first subsurface reservoir in Taiwan. Originally, the water quality of the reservoir is good. The reservoir has had the salinity problem since 1991 and it became more and more serious from 1992 until 1994. Possible reason of the salinity problem was the shortage of rainfall or the leakage of the subsurface barrier which caused the seawater intrusion. The present study aimed to determine the leakage position of subsurface barrier that caused the salinity problem. In order to perform the simulation for different possible leakage position of the subsurface reservoir, a Groundwater Modeling System (GMS) is used to define soils layer data, hydro-geological parameters, initial conditions, boundary conditions and the generation of three dimension meshes. A three dimension FEMWATER(Yeh , 1996) numerical model was adopted to find the possible leakage position of the subsurface barrier and location of seawater intrusion by comparing the simulation of different possible leakage with the observations. 1.By assuming the leakage position in the bottom of barrier, the simulated numerical result matched the observation better than the other assumed leakage positions. It showed that the most possible leakage position was at the bottom of the barrier. 2.The research applied three dimension FEMWATER and GMS as an interface

Equatorial Indian Ocean subsurface current variability in an Ocean General Circulation Model

Science.gov (United States)

Gnanaseelan, C.; Deshpande, Aditi

2018-03-01

The variability of subsurface currents in the equatorial Indian Ocean is studied using high resolution Ocean General Circulation Model (OGCM) simulations during 1958-2009. February-March eastward equatorial subsurface current (ESC) shows weak variability whereas strong variability is observed in northern summer and fall ESC. An eastward subsurface current with maximum amplitude in the pycnocline is prominent right from summer to winter during strong Indian Ocean Dipole (IOD) years when air-sea coupling is significant. On the other hand during weak IOD years, both the air-sea coupling and the ESC are weak. This strongly suggests the role of ESC on the strength of IOD. The extension of the ESC to the summer months during the strong IOD years strengthens the oceanic response and supports intensification and maintenance of IODs through modulation of air sea coupling. Although the ESC is triggered by equatorial winds, the coupled air-sea interaction associated with IODs strengthens the ESC to persist for several seasons thereby establishing a positive feedback cycle with the surface. This suggests that the ESC plays a significant role in the coupled processes associated with the evolution and intensification of IOD events by cooling the eastern basin and strengthening thermocline-SST (sea surface temperature) interaction. As the impact of IOD events on Indian summer monsoon is significant only during strong IOD years, understanding and monitoring the evolution of ESC during these years is important for summer monsoon forecasting purposes. There is a westward phase propagation of anomalous subsurface currents which persists for a year during strong IOD years, whereas such persistence or phase propagation is not seen during weak IOD years, supporting the close association between ESC and strength of air sea coupling during strong IOD years. In this study we report the processes which strengthen the IOD events and the air sea coupling associated with IOD. It also unravels

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...

Cover Crops for Managing Stream Water Quantity and Improving Stream Water Quality of Non-Tile Drained Paired Watersheds

Directory of Open Access Journals (Sweden)

Gurbir Singh

2018-04-01

Full Text Available In the Midwestern United States, cover crops are being promoted as a best management practice for managing nutrient and sediment losses from agricultural fields through surface and subsurface water movement. To date, the water quality benefits of cover crops have been inferred primarily from plot scale studies. This project is one of the first to analyze the impacts of cover crops on stream water quality at the watershed scale. The objective of this research was to evaluate nitrogen, phosphorus, and sediment loss in stream water from a no-till corn-soybean rotation planted with winter cover crops cereal rye (Secale cereale and hairy vetch (Vicia villosa in non-tile drained paired watersheds in Illinois, USA. The paired watersheds are under mixed land use (agriculture, forest, and pasture. The control watershed had 27 ha of row-crop agriculture, and the treatment watershed had 42 ha of row crop agriculture with cover crop treatment (CC-treatment. During a 4-year calibration period, 42 storm events were collected and Event Mean Concentrations (EMCs for each storm event were calculated for total suspended solids (TSS, nitrate-N (NO3-N, ammonia-N (NH4-N, dissolved reactive phosphorus (DRP, and total discharge. Predictive regression equations developed from the calibration period were used for calculating TSS, NO3-N, NH4-N, and DRP losses of surface runoff for the CC-treatment watershed. The treatment period consisted of total 18 storm events, seven of which were collected during the cereal rye, eight in the hairy vetch cover crop season and three during cash crop season. Cover crops reduced TSS and discharge by 33% and 34%, respectively in the CC-treatment watershed during the treatment period. However, surprisingly, EMCs for NO3-N, NH4-N, and DRP did not decrease. Stream discharge from the paired-watersheds will continue to be monitored to determine if the current water quality results hold or new patterns emerge.

Outcomes of endoscopic repair of cerebrospinal fluid rhinorrhea without lumbar drains.

Science.gov (United States)

Adams, Austin S; Russell, Paul T; Duncavage, James A; Chandra, Rakesh K; Turner, Justin H

2016-11-01

Lumbar drains (LD) are commonly used during endoscopic repair of cerebrospinal fluid (CSF) rhinorrhea, either to facilitate graft healing or to monitor CSF fluid dynamics. However, the indications and necessity of LD placement remains controversial. The current study sought to evaluate endoscopic CSF leak repair outcomes in the setting of limited LD use. Patients who underwent endoscopic repair of CSF rhinorrhea between 2004 and 2014 were identified by a review of medical records. Demographic and clinical data were extracted and compared between patients who had surgery with and patients who had surgery without a perioperative LD. A univariate analysis was performed to identify factors predictive of recurrence. A total of 107 patients (116 surgical procedures) were identified, with a mean follow-up of 15.8 months. Eighty-eight of 107 patients (82.2%) had surgery without an LD. The mean hospital stay was 4.48 days in the LD group versus 1.03 days in the non-LD group (p CSF leak repair was not associated with reduced recurrence rates, regardless of leak etiology, and resulted in a significant increase in hospital length of stay. Although the use of perioperative LDs to monitor CSF dynamics may have some therapeutic and diagnostic advantages, it may not be associated with clinically significant improvements in patient outcomes or recurrence rates.

Ground-air temperature tracking and multi-year cycles in the subsurface temperature time series at geothermal climat e-change observatory

Czech Academy of Sciences Publication Activity Database

Čermák, Vladimír; Bodri, L.; Šafanda, Jan; Krešl, Milan; Dědeček, Petr

2014-01-01

Roč. 58, č. 3 (2014), s. 406-424 ISSN 0039-3169 R&D Projects: GA ČR(CZ) GAP210/11/0183; GA AV ČR KSK3046108 Institutional support: RVO:67985530 Keywords : borehole observatory * temperature monitoring * climate change * subsurface temperature Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.806, year: 2014

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.

Demonstration of innovative monitoring technologies at the Savannah River Integrated Demonstration Site

Energy Technology Data Exchange (ETDEWEB)

Rossabi, J. [Westinghouse Savannah River Co., Aiken, SC (United States); Jenkins, R.A.; Wise, M.B. [Oak Ridge National Lab., TN (United States)] [and others

1993-12-31

The Department of Energy`s Office of Technology Development initiated an Integrated Demonstration Program at the Savannah River Site in 1989. The objective of this program is to develop, demonstrate, and evaluate innovative technologies that can improve present-day environmental restoration methods. The Integrated Demonstration Program at SRS is entitled ``Cleanup of Organics in Soils and Groundwater at Non-Arid Sites.`` New technologies in the areas of drilling, characterization, monitoring, and remediation are being demonstrated and evaluated for their technical performance and cost effectiveness in comparison with baseline technologies. Present site characterization and monitoring methods are costly, time-consuming, overly invasive, and often imprecise. Better technologies are required to accurately describe the subsurface geophysical and geochemical features of a site and the nature and extent of contamination. More efficient, nonintrusive characterization and monitoring techniques are necessary for understanding and predicting subsurface transport. More reliable procedures are also needed for interpreting monitoring and characterization data. Site characterization and monitoring are key elements in preventing, identifying, and restoring contaminated sites. The remediation of a site cannot be determined without characterization data, and monitoring may be required for 30 years after site closure.

Demonstration of innovative monitoring technologies at the Savannah River Integrated Demonstration Site

International Nuclear Information System (INIS)

Rossabi, J.; Jenkins, R.A.; Wise, M.B.

1993-01-01

The Department of Energy's Office of Technology Development initiated an Integrated Demonstration Program at the Savannah River Site in 1989. The objective of this program is to develop, demonstrate, and evaluate innovative technologies that can improve present-day environmental restoration methods. The Integrated Demonstration Program at SRS is entitled ''Cleanup of Organics in Soils and Groundwater at Non-Arid Sites.'' New technologies in the areas of drilling, characterization, monitoring, and remediation are being demonstrated and evaluated for their technical performance and cost effectiveness in comparison with baseline technologies. Present site characterization and monitoring methods are costly, time-consuming, overly invasive, and often imprecise. Better technologies are required to accurately describe the subsurface geophysical and geochemical features of a site and the nature and extent of contamination. More efficient, nonintrusive characterization and monitoring techniques are necessary for understanding and predicting subsurface transport. More reliable procedures are also needed for interpreting monitoring and characterization data. Site characterization and monitoring are key elements in preventing, identifying, and restoring contaminated sites. The remediation of a site cannot be determined without characterization data, and monitoring may be required for 30 years after site closure

Adaptive management for subsurface pressure and plume control in application to geological CO2 storage

Science.gov (United States)

Gonzalez-Nicolas, A.; Cihan, A.; Birkholzer, J. T.; Petrusak, R.; Zhou, Q.; Riestenberg, D. E.; Trautz, R. C.; Godec, M.

2016-12-01

Industrial-scale injection of CO2 into the subsurface can cause reservoir pressure increases that must be properly controlled to prevent any potential environmental impact. Excessive pressure buildup in reservoir may result in ground water contamination stemming from leakage through conductive pathways, such as improperly plugged abandoned wells or distant faults, and the potential for fault reactivation and possibly seal breaching. Brine extraction is a viable approach for managing formation pressure, effective stress, and plume movement during industrial-scale CO2 injection projects. The main objectives of this study are to investigate suitable different pressure management strategies involving active brine extraction and passive pressure relief wells. Adaptive optimized management of CO2 storage projects utilizes the advanced automated optimization algorithms and suitable process models. The adaptive management integrates monitoring, forward modeling, inversion modeling and optimization through an iterative process. In this study, we employ an adaptive framework to understand primarily the effects of initial site characterization and frequency of the model update (calibration) and optimization calculations for controlling extraction rates based on the monitoring data on the accuracy and the success of the management without violating pressure buildup constraints in the subsurface reservoir system. We will present results of applying the adaptive framework to test appropriateness of different management strategies for a realistic field injection project.

Heating systems for heating subsurface formations

Science.gov (United States)

Nguyen, Scott Vinh [Houston, TX; Vinegar, Harold J [Bellaire, TX

2011-04-26

Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

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

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

Integrated geomechanical modelling at TNO for assessement of deep subsurface risks

NARCIS (Netherlands)

Orlic, B.; Fokker, P.; Zijl, W.; Scheffers, B.

2001-01-01

Public authorities, E & P and the mining industry increasingly demand fundamental insight and accurate predictions on subsurface and surface deformation and damage due to exploitation of subsurface natural resources, and subsurface storage of energy residues (e.g. CO2). At this moment deformation is

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.

In Situ Monitoring of Chemical Reactions at a Solid-Water Interface by Femtosecond Acoustics.

Science.gov (United States)

Shen, Chih-Chiang; Weng, Meng-Yu; Sheu, Jinn-Kong; Yao, Yi-Ting; Sun, Chi-Kuang

2017-11-02

Chemical reactions at a solid-liquid interface are of fundamental importance. Interfacial chemical reactions occur not only at the very interface but also in the subsurface area, while existing monitoring techniques either provide limited spatial resolution or are applicable only for the outmost atomic layer. Here, with the aid of the time-domain analysis with femtosecond acoustics, we demonstrate a subatomic-level-resolution technique to longitudinally monitor chemical reactions at solid-water interfaces, capable of in situ monitoring even the subsurface area under atmospheric conditions. Our work was proven by monitoring the already-known anode oxidation process occurring during photoelectrochemical water splitting. Furthermore, whenever the oxide layer thickness equals an integer  number of the effective atomic layer thickness, the measured acoustic echo will show higher signal-to-noise ratios with reduced speckle noise, indicating the quantum-like behavior of this coherent-phonon-based technique.

A trench study to assess transfer of pesticides in subsurface lateral flow for a soil with contrasting texture on a sloping vineyard in Beaujolais.

Science.gov (United States)

Peyrard, X; Liger, L; Guillemain, C; Gouy, V

2016-01-01

Subsurface lateral flow in both texture-contrast soils and catchments with shallow bedrock is suspected to be a non-point source of contamination of watercourses by pesticides used in agriculture. As a case study, the north of the Beaujolais region (eastern France) provides a favorable environment for such contamination due to its agro-pedo-climatic conditions. Environments seen in the Beaujolais region include intense viticulture, permeable and shallow soils, steep hillslopes, and storms that occur during the periods of pesticide application. Watercourse contamination by pesticides has been widely observed in this region, and offsite pesticide transport by subsurface lateral flow is suspected to be involved in diffuse and chronic presence of pesticides in surface water. In order to confirm and quantify the potential role of such processes in pesticide transfer, an automated trench system has been designed. The trench was set up on a steep farmed hillslope in a texture-contrast soil. It was equipped with a tipping bucket flow meter and an automatic sampler to monitor pesticide concentrations in lateral flow at fine resolution, by means of a flow-dependent sampling strategy. Four pesticides currently used in vine growing were studied to provide a range of mobility properties: one insecticide (chlorpyrifos-methyl) and three fungicides (spiroxamine, tebuconazole, and dimethomorph). With this system, it was possible to study pesticide concentration dynamics in the subsurface lateral flow, generated by substantial rainfall events following pesticide applications. The experimental design ascertained to be a suitable method in which to monitor subsurface lateral flow and related transfer of pesticides.

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

An electrical resistivity-based method for investigation of subsurface structure

Science.gov (United States)

Alves Meira Neto, A.; Litwin, D.; Troch, P. A. A.; Ferre, T. P. A.

2017-12-01

Resolving the spatial distribution of soil porosity within the subsurface is of great importance for understanding flow and transport within heterogeneous media. Additionally, porosity patterns can be associated with the availability of water and carbon dioxide that will drive geochemical reactions and constrain microbiological growth. The use of controlled experimentation has the potential to circumvent problems related to the external and internal variability of natural systems, while also allowing a higher degree of observability. In this study, we suggest an ERT-based method of retrieving porosity fields based on the application of Archie's law associated with an experimental procedure that can be used in laboratory-scale studies. We used a 2 cubic meter soil lysimeter, equipped with 238 electrodes distributed along its walls for testing the method. The lysimeter serves as a scaled-down version of the highly monitored artificial hillslopes at the Landscape Evolution Observatory (LEO) located at Biosphere 2 - University of Arizona. The capability of the ERT system in deriving spatially distributed patterns of porosity with respect to its several sources of uncertainty was numerically evaluated. The results will be used to produce an optimal experimental design and for assessing the reliability of experimental results. This novel approach has the potential to further resolve subsurface heterogeneity within the LEO project, and highlight the use of ERT-derived results for hydro-bio-geochemical studies.

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.

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.

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.

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.

Localized Glacier Deformation Associated with Filling and Draining of a Glacier-Dammed Lake and Implications for Outburst Flood Hydraulics

Science.gov (United States)

Cunico, M. L.; Walder, J. S.; Fountain, A. G.; Trabant, D. C.

2001-12-01

During the summer of 2000, we measured displacements of 22 survey targets on the surface of Kennicott Glacier, Alaska, in the vicinity of Hidden Creek Lake, an ice-dammed lake in a tributary valley that fills and drains annually. Targets were distributed over a domain about equal in width to the lake, from near the glacier/lake margin to a distance of about 1 km from the margin. Targets were surveyed over a 24-day period as the lake filled and then drained. Lake stage was independently monitored. Vertical movement of targets generally fell off with distance d from the lake. As the lake filled, targets with d typically about 0.5 m/d--with a few targets rising slightly faster than the lake. The rate of vertical movement fell off rapidly with distance from the lake: for d = ca. 600 m--roughly twice the local ice thickness--targets moved upward only about 10% as fast as lake stage. Vertical movement of targets with d > ca. 1 km seemed to be uncorrelated with lake stage. The general pattern is consistent with the idea that a wedge of water extended beneath the glacier to a distance of perhaps 300 to 400 m from the visible margin of the lake and exerts buoyant stresses on the ice that were transmitted into the main body of the glacier and caused flexure. This scenario bears some resemblance to tidal deflections of ice shelves or tidewater glaciers. For a given value of lake stage, target elevations were invariably higher as the lake drained than as the lake filled. Moreover, survey targets at a distance of about 400 m or more from the lake continued to rise for some time even after the lake began to drain. The lag time between the beginning of lake drainage and the beginning of target downdrop increased with distance from the lake, with the lag being about 14 hours at a distance of 400 m from the lake. (The lake drained completely in approximately 75 hours.) The likeliest explanations for the departure from reversibility and the existence of the time lag are either (i) a

Subsurface Contaminants Focus Area annual report 1997

International Nuclear Information System (INIS)

1997-01-01

In support of its vision for technological excellence, the Subsurface Contaminants Focus Area (SCFA) has identified three strategic goals. The three goals of the SCFA are: Contain and/or stabilize contamination sources that pose an imminent threat to surface and ground waters; Delineate DNAPL contamination in the subsurface and remediate DNAPL-contaminated soils and ground water; and Remove a full range of metal and radionuclide contamination in soils and ground water. To meet the challenges of remediating subsurface contaminants in soils and ground water, SCFA funded more than 40 technologies in fiscal year 1997. These technologies are grouped according to the following product lines: Dense Nonaqueous-Phase Liquids; Metals and Radionuclides; Source Term Containment; and Source Term Remediation. This report briefly describes the SCFA 1997 technologies and showcases a few key technologies in each product line

Complete Subsurface Elemental Composition Measurements With PING

Science.gov (United States)

Parsons, A. M.

2012-01-01

The Probing In situ with Neutrons and Gamma rays (PING) instrument will measure the complete bulk elemental composition of the subsurface of Mars as well as any other solid planetary body. PING can thus be a highly effective tool for both detailed local geochemistry science investigations and precision measurements of Mars subsurface reSOurces in preparation for future human exploration. As such, PING is thus fully capable of meeting a majority of both ncar and far term elements in Challenge #1 presented for this conference. Measuring the ncar subsurface composition of Mars will enable many of the MEPAG science goals and will be key to filling an important Strategic Knowledge Gap with regard to In situ Resources Utilization (ISRU) needs for human exploration. [1, 2] PING will thus fill an important niche in the Mars Exploration Program.

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.

Translucent Radiosity: Efficiently Combining Diffuse Inter-Reflection and Subsurface Scattering.

Science.gov (United States)

Sheng, Yu; Shi, Yulong; Wang, Lili; Narasimhan, Srinivasa G

2014-07-01

It is hard to efficiently model the light transport in scenes with translucent objects for interactive applications. The inter-reflection between objects and their environments and the subsurface scattering through the materials intertwine to produce visual effects like color bleeding, light glows, and soft shading. Monte-Carlo based approaches have demonstrated impressive results but are computationally expensive, and faster approaches model either only inter-reflection or only subsurface scattering. In this paper, we present a simple analytic model that combines diffuse inter-reflection and isotropic subsurface scattering. Our approach extends the classical work in radiosity by including a subsurface scattering matrix that operates in conjunction with the traditional form factor matrix. This subsurface scattering matrix can be constructed using analytic, measurement-based or simulation-based models and can capture both homogeneous and heterogeneous translucencies. Using a fast iterative solution to radiosity, we demonstrate scene relighting and dynamically varying object translucencies at near interactive rates.

Impact of a drain field plate on the breakdown characteristics of AlInN/GaN MOSHEMT

Science.gov (United States)

Jena, Kanjalochan; Swain, Raghunandan; Lenka, T. R.

2015-11-01

In this paper, a novel AlInN/GaN metal oxide semiconductor high electron mobility transistor (MOSHEMT) employing the drain field plate technique is proposed and the effect of a drain field plate on the breakdown voltage (BV) is investigated. A reduction of the peak electric field is required to achieve AlInN/GaN MOSHEMTs with a high BV. The proposed AlInN/GaN MOSHEMT with both gate and drain field plates simultaneously reduces the electric field concentration at the gate and the drain edge by decreasing the potential gradient along the channel for the 2 dimensional electron gas (2DEG). The reduction in the peak electric field at the drain edge of the proposed device leads to a 57% increase in BV compared with the BV for an AlInN/GaN MOSHEMT with a gate field plate only. A significantly higher BV can be achieved by optimizing the gate-to-drain distance (L gd ), the length of the drain field plate (L dfp ) and the thickness of the SiN passivation layer thickness (T SiN ). A detailed breakdown analysis of the device was carried out using Silvaco Technology Computer Aided Design (TCAD). The detailed numerical simulations were done by using the non-local energy balance (EB) transport model, which was calibrated with the previously published experimental results. The results showed a great potential for applications of the drain-field-plated AlInN/GaN MOSHEMT to deliver high currents and high powers in microwave technologies.

Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda

Energy Technology Data Exchange (ETDEWEB)

Pyrak-Nolte, Laura J [Purdue Univ., West Lafayette, IN (United States); DePaolo, Donald J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Pietraß, Tanja [USDOE Office of Science, Washington, DC (United States)

2015-05-22

From beneath the surface of the earth, we currently obtain about 80-percent of the energy our nation consumes each year. In the future we have the potential to generate billions of watts of electrical power from clean, green, geothermal energy sources. Our planet’s subsurface can also serve as a reservoir for storing energy produced from intermittent sources such as wind and solar, and it could provide safe, long-term storage of excess carbon dioxide, energy waste products and other hazardous materials. However, it is impossible to underestimate the complexities of the subsurface world. These complexities challenge our ability to acquire the scientific knowledge needed for the efficient and safe exploitation of its resources. To more effectively harness subsurface resources while mitigating the impacts of developing and using these resources, the U.S. Department of Energy established SubTER – the Subsurface Technology and Engineering RD&D Crosscut team. This DOE multi-office team engaged scientists and engineers from the national laboratories to assess and make recommendations for improving energy-related subsurface engineering. The SubTER team produced a plan with the overall objective of “adaptive control of subsurface fractures and fluid flow.”This plan revolved around four core technological pillars—Intelligent Wellbore Systems that sustain the integrity of the wellbore environment; Subsurface Stress and Induced Seismicity programs that guide and optimize sustainable energy strategies while reducing the risks associated with subsurface injections; Permeability Manipulation studies that improve methods of enhancing, impeding and eliminating fluid flow; and New Subsurface Signals that transform our ability to see into and characterize subsurface systems. The SubTER team developed an extensive R&D plan for advancing technologies within these four core pillars and also identified several areas where new technologies would require additional basic research

Subsurface Treatment of Domestic Wastewater Using Single Domicile Constructed Wetlands

Science.gov (United States)

Aseltyne, T.; Steer, D.; Fraser, L.

2001-05-01

Analysis of one year of input versus output water quality monitoring data from nine household wastewater treatment wetlands in western Ohio indicates that these systems substantially reduce effluent loads delivered to the local watershed. Overall performance as measured by output water quality improvement varies widely between the nine systems despite their close proximity and identical design. These three-cell systems (septic tank with 2 subsurface wetland cells) are found to reduce biological oxygen demand (BOD) 70-98%, fecal coliform 60-99.9%, NH3 29-97%, Phosphorus 21-99.9% and total suspended solids (TSS) up to 97%. NO3/NO2 readings were only taken at the second wetland cell, but show that NO3/NO2 levels are at 0.005-5.01 mg/l and well below the USEPA standards for discharge from a wetland. On average, the pH of the wastewater increases from 6.6 at the septic tank to 8.7 at the wetland output. Nearly all the monitoring data indicate clear decreases in nutrient loads and bacteria though individual systems are found to non-systematically fail to meet EPA discharge guidelines for one or more of the monitored loads. Preliminary analysis of the data indicates a decrease in overall efficiency of the wetlands in April that may be related to seasonal factors. These systems will be monitored for the next three years in order to relate changing performance trends to seasonal variability.

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.

Tetracycline Resistance in the Subsurface of a Poultry Farm: Influence of Poultry Wastes

Science.gov (United States)

You, Y.; Ball, W. P.; Ward, M. J.; Hilpert, M.

2007-12-01

Concentrated animal feeding operations (CAFOs) are considered to be important man-made reservoir of antibiotic resistant bacteria. Using the electromagnetic induction (EMI) method of geophysical characterization, we measured the apparent subsurface electrical conductivity (ECa) at a CAFO site in order to assess the movement of pollutants associated with animal waste. The map of ECa and other available data suggest that (1) soil surrounding a poultry litter storage shed is contaminated by poultry waste, (2) a contamination plume in the subsurface emanates from that shed, and (3) the development of that plume is due to groundwater flow. We focused on understanding the spread of tetracycline resistance (Tc\\tiny R), because tetracycline is one of the most frequently used antibiotics in food animal production and therefore probably used at our field site. Microbiological experiments show the presence of Tc\\tiny R bacteria in the subsurface and indicate higher concentrations in the top soil than in the aquifer. Environmental DNA was extracted to identify CAFO- associated Tc\\tiny R genes and to explore a link between the presence of Tc\\tiny R and CAFO practices. A "shot-gun" cloning approach is under development to target the most prevalent Tc\\tiny R gene. This gene will be monitored in future experiments, in which we will study the transmission of Tc\\tiny R to naive E.~coli under selective pressure of Tc. Experimental results will be used to develop a mathematical/numerical model in order to describe the transmission process and to subsequently make estimates regarding the large-scale spread of antibiotic resistance.

Theoretical and experimental investigations of ferrofluids for guiding and detecting liquids in the subsurface. FY 1997 annual report

Energy Technology Data Exchange (ETDEWEB)

Moridis, G.J.; Borglin, S.E.; Oldenburg, C.M.; Becker, A.

1998-03-01

Ferrofluids are stable colloidal suspensions of magnetic particles in various carrier liquids with high saturation magnetizations, which can be manipulated in virtually any fashion, defying gravitational or viscous forces in response to external magnetic fields. In this report, the authors review the results of their investigation of the potential of ferrofluids (1) to accurately and effectively guide reactants (for in-situ treatment) or barrier liquids (low-viscosity permeation grouts) to contaminated target zones in the subsurface using electromagnetic forces, and (2) to trace the movement and position of liquids injected in the subsurface using geophysical methods. They investigate the use of ferrofluids to enhance the efficiency of in-situ treatment and waste containment through (a) accurate guidance and delivery of reagent liquids to the desired subsurface contamination targets and/or (b) effective sweeping of the contaminated zone as ferrofluids move from the application point to an attracting magnet/collection point. They also investigate exploiting the strong magnetic signature of ferrofluids to develop a method for monitoring of liquid movement and position during injection using electromagnetic methods. The authors demonstrated the ability to induce ferrofluid movement in response to a magnetic field, and measured the corresponding magnetopressure. They demonstrated the feasibility of using conventional magnetometry for detecting subsurface zones of various shapes containing ferrofluids for tracing liquids injected for remediation or barrier formation. Experiments involving spherical, cylindrical and horizontal slabs showed a very good agreement between predictions and measurements.

Theoretical and experimental investigations of ferrofluids for guiding and detecting liquids in the subsurface. FY 1997 annual report

International Nuclear Information System (INIS)

Moridis, G.J.; Borglin, S.E.; Oldenburg, C.M.; Becker, A.

1998-03-01

Ferrofluids are stable colloidal suspensions of magnetic particles in various carrier liquids with high saturation magnetizations, which can be manipulated in virtually any fashion, defying gravitational or viscous forces in response to external magnetic fields. In this report, the authors review the results of their investigation of the potential of ferrofluids (1) to accurately and effectively guide reactants (for in-situ treatment) or barrier liquids (low-viscosity permeation grouts) to contaminated target zones in the subsurface using electromagnetic forces, and (2) to trace the movement and position of liquids injected in the subsurface using geophysical methods. They investigate the use of ferrofluids to enhance the efficiency of in-situ treatment and waste containment through (a) accurate guidance and delivery of reagent liquids to the desired subsurface contamination targets and/or (b) effective sweeping of the contaminated zone as ferrofluids move from the application point to an attracting magnet/collection point. They also investigate exploiting the strong magnetic signature of ferrofluids to develop a method for monitoring of liquid movement and position during injection using electromagnetic methods. The authors demonstrated the ability to induce ferrofluid movement in response to a magnetic field, and measured the corresponding magnetopressure. They demonstrated the feasibility of using conventional magnetometry for detecting subsurface zones of various shapes containing ferrofluids for tracing liquids injected for remediation or barrier formation. Experiments involving spherical, cylindrical and horizontal slabs showed a very good agreement between predictions and measurements

Bacterial communities associated with subsurface geochemical processes in continental serpentinite springs.

Science.gov (United States)

Brazelton, William J; Morrill, Penny L; Szponar, Natalie; Schrenk, Matthew O

2013-07-01

Reactions associated with the geochemical process of serpentinization can generate copious quantities of hydrogen and low-molecular-weight organic carbon compounds, which may provide energy and nutrients to sustain subsurface microbial communities independently of the photosynthetically supported surface biosphere. Previous microbial ecology studies have tested this hypothesis in deep sea hydrothermal vents, such as the Lost City hydrothermal field. This study applied similar methods, including molecular fingerprinting and tag sequencing of the 16S rRNA gene, to ultrabasic continental springs emanating from serpentinizing ultramafic rocks. These molecular surveys were linked with geochemical measurements of the fluids in an interdisciplinary approach designed to distinguish potential subsurface organisms from those derived from surface habitats. The betaproteobacterial genus Hydrogenophaga was identified as a likely inhabitant of transition zones where hydrogen-enriched subsurface fluids mix with oxygenated surface water. The Firmicutes genus Erysipelothrix was most strongly correlated with geochemical factors indicative of subsurface fluids and was identified as the most likely inhabitant of a serpentinization-powered subsurface biosphere. Both of these taxa have been identified in multiple hydrogen-enriched subsurface habitats worldwide, and the results of this study contribute to an emerging biogeographic pattern in which Betaproteobacteria occur in near-surface mixing zones and Firmicutes are present in deeper, anoxic subsurface habitats.

Enhanced performance of amorphous In-Ga-Zn-O thin-film transistors using different metals for source/drain electrodes

Science.gov (United States)

Pyo, Ju-Young; Cho, Won-Ju

2017-09-01

In this paper, we propose an amorphous indium gallium zinc oxide (a-IGZO) thin-film transistor (TFT) with off-planed source/drain electrodes. We applied different metals for the source/drain electrodes with Ni and Ti to control the work function as high and low. When we measured the configuration of Ni to drain and source to Ti, the a-IGZO TFT showed increased driving current, decreased leakage current, a high on/off current ratio, low subthreshold swing, and high mobility. In addition, we conducted a reliability test with a gate bias stress test at various temperatures. The results of the reliability test showed the Ni drain and Ti drain had an equivalent effective energy barrier height. Thus, we confirmed that the proposed off-planed structure improved the electrical characteristics of the fabricated devices without any degradation of characteristics. Through the a-IGZO TFT with different source/drain electrode metal engineering, we realized high-performance TFTs for next-generation display devices.

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...

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.

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.

The Mojave Subsurface Bio-Geochemistry Explorer (MOSBE)

Science.gov (United States)

Guerrero, J.; Beegle, L.; Abbey, W.; Bhartia, R.; Kounaves, S.; Russell, M.; Towles, D.

2012-01-01

The MOSBE Team has developed a terrestrial field campaign to explore two subsurface biological habitats under the Mojave Desert. This field campaign will not only help us understand terrestrial desert biology, but also will develop methodologies and strategies for potential future Mars missions that would seek to explore the Martian subsurface. We have proposed to the ASTEP program to integrate a suite of field demonstrated instruments with a 20 m subsurface drill as a coherent unit, the Mojave Subsurface Bio-geochemistry Explorer. The ATK Space Modular Planetary Drill System (MPDS) requires no drilling fluid, which allows aseptic sampling, can penetrate lithic ground up to 20 meters of depth, and utilizes less than 100 Watts throughout the entire depth. The drill has been developed and demonstrated in field testing to a depth of 10 meters in Arizona, December 2002. In addition to caching a continuous core throughout the drilling depth, it also generates and caches cuttings and fines that are strata-graphically correlated with the core. As a core segment is brought to the surface, it will be analyzed for texture and structure by a color microscopic imager and for relevant chemistry and mineralogy with a UV fluorescence/Raman spectrometer. Organic and soluble ionic species will be identified through two instruments -- a microcapillary electrophoresis, and an ion trap mass spectrometer that have been developed under PIDDP, ASTID and MIDP funding.

Development, yield and quality attributes of sugarcane cultivars fertigated by subsurface drip irrigation

Directory of Open Access Journals (Sweden)

André L. B. de O. Silva

2016-06-01

Full Text Available ABSTRACT The present study aimed to evaluate the development, yield and quality of four sugarcane cultivars fertigated by subsurface drip system. The experiment was carried out in Campinas-SP, Brazil, from January 2012 to November 2013, with the cultivars SP79-1011, IACSP94-2101, IACSP94-2094 and IACSP95-5000 subjected to daily irrigations. The irrigations depths were applied to bring soil moisture to field capacity. Soil moisture was monitored using soil moisture probes. Samples were collected along the crop cycle in order to evaluate crop development and yield, at the end of the first and second ratoons. Stalk height showed good correlation for the estimation of crop yield, with R2 equal to or higher than 0.96. The cultivar IACSP95-5000 showed the highest yield in the first ratoon. In the second ratoon the highest yield was observed in IACSP94-2101, followed by IACSP95-5000 and SP79-1011. Considering the yield results associated with the technological analysis, such as soluble solids content and apparent sucrose, the cultivar IACSP95-5000 excelled the others in the cultivation under subsurface drip irrigation.

Geosystem services:A concept in support of sustainable development of the subsurface

NARCIS (Netherlands)

van Ree, C.C.D.F.; van Beukering, P.J.H.

2016-01-01

Because functions of the subsurface are hidden from view, its important role in society is often taken for granted. Underground use in cities and subsurface resource extraction rapidly increase. Ensuring sustainability of the subsurface role requires balancing between exploitation and conservation,

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...

Computer modeling and laboratory experiments of a specific borehole to surface electrical monitoring technique (BSEMT)

NARCIS (Netherlands)

Meekes, J.A.C.; Zhang, X.; Abdul Fattah, R.

2011-01-01

Geophysical monitoring of the dynamical behavior of subsurface reservoirs (oil, gas, CO2) remains an important issue in geophysical research. A new idea for reservoir monitoring based on electrical resistivity tomography was developed at TNO. The essential element of the so-called BSEMT (Borehole to

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

Peeking Beneath the Caldera: Communicating Subsurface Knowledge of Newberry Volcano

Science.gov (United States)

Mark-Moser, M.; Rose, K.; Schultz, J.; Cameron, E.

2016-12-01

"Imaging the Subsurface: Enhanced Geothermal Systems and Exploring Beneath Newberry Volcano" is an interactive website that presents a three-dimensional subsurface model of Newberry Volcano developed at National Energy Technology Laboratory (NETL). Created using the Story Maps application by ArcGIS Online, this format's dynamic capabilities provide the user the opportunity for multimedia engagement with the datasets and information used to build the subsurface model. This website allows for an interactive experience that the user dictates, including interactive maps, instructive videos and video capture of the subsurface model, and linked information throughout the text. This Story Map offers a general background on the technology of enhanced geothermal systems and the geologic and development history of Newberry Volcano before presenting NETL's modeling efforts that support the installation of enhanced geothermal systems. The model is driven by multiple geologic and geophysical datasets to compare and contrast results which allow for the targeting of potential EGS sites and the reduction of subsurface uncertainty. This Story Map aims to communicate to a broad audience, and provides a platform to effectively introduce the model to researchers and stakeholders.

Techniques for assessing the performance of in situ bioreduction and immobilization of metals and radionuclides in contaminated subsurface environments

Energy Technology Data Exchange (ETDEWEB)

Jardine, P.M.; Watson, D.B.; Blake, D.A.; Beard, L.P.; Brooks, S.C.; Carley, J.M.; Criddle, C.S.; Doll, W.E.; Fields, M.W.; Fendorf, S.E.; Geesey, G.G.; Ginder-Vogel, M.; Hubbard, S.S.; Istok, J.D.; Kelly, S.; Kemner, K.M.; Peacock, A.D.; Spalding, B.P.; White, D.C.; Wolf, A.; Wu, W.; Zhou, J.

2004-11-14

Department of Energy (DOE) facilities within the weapons complex face a daunting challenge of remediating huge below inventories of legacy radioactive and toxic metal waste. More often than not, the scope of the problem is massive, particularly in the high recharge, humid regions east of the Mississippi river, where the off-site migration of contaminants continues to plague soil water, groundwater, and surface water sources. As of 2002, contaminated sites are closing rapidly and many remediation strategies have chosen to leave contaminants in-place. In situ barriers, surface caps, and bioremediation are often the remedial strategies of chose. By choosing to leave contaminants in-place, we must accept the fact that the contaminants will continue to interact with subsurface and surface media. Contaminant interactions with the geosphere are complex and investigating long term changes and interactive processes is imperative to verifying risks. We must be able to understand the consequences of our action or inaction. The focus of this manuscript is to describe recent technical developments for assessing the performance of in situ bioremediation and immobilization of subsurface metals and radionuclides. Research within DOE's NABIR and EMSP programs has been investigating the possibility of using subsurface microorganisms to convert redox sensitive toxic metals and radionuclides (e.g. Cr, U, Tc, Co) into a less soluble, less mobile forms. Much of the research is motivated by the likelihood that subsurface metal-reducing bacteria can be stimulated to effectively alter the redox state of metals and radionuclides so that they are immobilized in situ for long time periods. The approach is difficult, however, since subsurface media and waste constituents are complex with competing electron acceptors and hydrogeological conditions making biostimulation a challenge. Performance assessment of in situ biostimulation strategies is also difficult and typically requires detailed

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.

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)

Reuse of drainage water in the Nile Delta; monitoring, modelling and analysis; final report Reuse of Drainage Water Project

NARCIS (Netherlands)

Staring Centrum, Instituut voor Onderzoek van het LandelijkGebied

1995-01-01

The effects of reusing drainage water have been evaluated and other options to increase the water utilization rate in Egypt explored. The results are an operational network for monitoring drainage water discharges and salinity along the major drains, a database for monitored drainage water

Martian sub-surface ionising radiation: biosignatures and geology

Directory of Open Access Journals (Sweden)

J. M. Ward

2007-07-01

Full Text Available The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation is of prime astrobiological interest. Here, we present modelling results of the absorbed radiation dose as a function of depth through the Martian subsurface, suitable for calculation of biomarker persistence. A second major implementation of this dose accumulation rate data is in application of the optically stimulated luminescence technique for dating Martian sediments.

We present calculations of the dose-depth profile in the Martian subsurface for various scenarios: variations of surface composition (dry regolith, ice, layered permafrost, solar minimum and maximum conditions, locations of different elevation (Olympus Mons, Hellas basin, datum altitude, and increasing atmospheric thickness over geological history. We also model the changing composition of the subsurface radiation field with depth compared between Martian locations with different shielding material, determine the relative dose contributions from primaries of different energies, and discuss particle deflection by the crustal magnetic fields.

Cultivation Of Deep Subsurface Microbial Communities

Science.gov (United States)

Obrzut, Natalia; Casar, Caitlin; Osburn, Magdalena R.

2018-01-01

The potential habitability of surface environments on other planets in our solar system is limited by exposure to extreme radiation and desiccation. In contrast, subsurface environments may offer protection from these stressors and are potential reservoirs for liquid water and energy that support microbial life (Michalski et al., 2013) and are thus of interest to the astrobiology community. The samples used in this project were extracted from the Deep Mine Microbial Observatory (DeMMO) in the former Homestake Mine at depths of 800 to 2000 feet underground (Osburn et al., 2014). Phylogenetic data from these sites indicates the lack of cultured representatives within the community. We used geochemical data to guide media design to cultivate and isolate organisms from the DeMMO communities. Media used for cultivation varied from heterotrophic with oxygen, nitrate or sulfate to autotrophic media with ammonia or ferrous iron. Environmental fluid was used as inoculum in batch cultivation and strains were isolated via serial transfers or dilution to extinction. These methods resulted in isolating aerobic heterotrophs, nitrate reducers, sulfate reducers, ammonia oxidizers, and ferric iron reducers. DNA sequencing of these strains is underway to confirm which species they belong to. This project is part of the NASA Astrobiology Institute Life Underground initiative to detect and characterize subsurface microbial life; by characterizing the intraterrestrials, the life living deep within Earth’s crust, we aim to understand the controls on how and where life survives in subsurface settings. Cultivation of terrestrial deep subsurface microbes will provide insight into the survival mechanisms of intraterrestrials guiding the search for these life forms on other planets.

Change in ocean subsurface environment to suppress tropical cyclone intensification under global warming

Science.gov (United States)

Huang, Ping; Lin, I. -I; Chou, Chia; Huang, Rong-Hui

2015-01-01

Tropical cyclones (TCs) are hazardous natural disasters. Because TC intensification is significantly controlled by atmosphere and ocean environments, changes in these environments may cause changes in TC intensity. Changes in surface and subsurface ocean conditions can both influence a TC's intensification. Regarding global warming, minimal exploration of the subsurface ocean has been undertaken. Here we investigate future subsurface ocean environment changes projected by 22 state-of-the-art climate models and suggest a suppressive effect of subsurface oceans on the intensification of future TCs. Under global warming, the subsurface vertical temperature profile can be sharpened in important TC regions, which may contribute to a stronger ocean coupling (cooling) effect during the intensification of future TCs. Regarding a TC, future subsurface ocean environments may be more suppressive than the existing subsurface ocean environments. This suppressive effect is not spatially uniform and may be weak in certain local areas. PMID:25982028

Molecular analysis of deep subsurface bacteria

International Nuclear Information System (INIS)

Jimenez Baez, L.E.

1989-09-01

Deep sediments samples from site C10a, in Appleton, and sites, P24, P28, and P29, at the Savannah River Site (SRS), near Aiken, South Carolina were studied to determine their microbial community composition, DNA homology and mol %G+C. Different geological formations with great variability in hydrogeological parameters were found across the depth profile. Phenotypic identification of deep subsurface bacteria underestimated the bacterial diversity at the three SRS sites, since bacteria with the same phenotype have different DNA composition and less than 70% DNA homology. Total DNA hybridization and mol %G+C analysis of deep sediment bacterial isolates suggested that each formation is comprised of different microbial communities. Depositional environment was more important than site and geological formation on the DNA relatedness between deep subsurface bacteria, since more 70% of bacteria with 20% or more of DNA homology came from the same depositional environments. Based on phenotypic and genotypic tests Pseudomonas spp. and Acinetobacter spp.-like bacteria were identified in 85 million years old sediments. This suggests that these microbial communities might have been adapted during a long period of time to the environmental conditions of the deep subsurface

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.

Importance of including small-scale tile drain discharge in the calibration of a coupled groundwater-surface water catchment model

DEFF Research Database (Denmark)

Hansen, Anne Lausten; Refsgaard, Jens Christian; Christensen, Britt Stenhøj Baun

2013-01-01

the catchment. In this study, a coupled groundwater-surface water model based on the MIKE SHE code was developed for the 4.7 km2 Lillebæk catchment in Denmark, where tile drain flow is a major contributor to the stream discharge. The catchment model was calibrated in several steps by incrementally including...... the observation data into the calibration to see the effect on model performance of including diverse data types, especially tile drain discharge. For the Lillebæk catchment, measurements of hydraulic head, daily stream discharge, and daily tile drain discharge from five small (1–4 ha) drainage areas exist....... The results showed that including tile drain data in the calibration of the catchment model improved its general performance for hydraulic heads and stream discharges. However, the model failed to correctly describe the local-scale dynamics of the tile drain discharges, and, furthermore, including the drain...

Agriculture and wildlife: ecological implications of subsurface irrigation drainage

Science.gov (United States)

A. Dennis Lemly

1994-01-01

Subsurface agricultural irrigation drainage is a wastewater with the potential to severely impact wetlands and wildlife populations. Widespread poisoning of migratory birds by drainwater contaminants has occurred in the western United States and waterfowl populations are threatened in the Pacific and Central flyways. Irrigated agriculture could produce subsurface...

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 ...

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…

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

Enamel subsurface damage due to tooth preparation with diamonds.

Science.gov (United States)

Xu, H H; Kelly, J R; Jahanmir, S; Thompson, V P; Rekow, E D

1997-10-01

In clinical tooth preparation with diamond burs, sharp diamond particles indent and scratch the enamel, causing material removal. Such operations may produce subsurface damage in enamel. However, little information is available on the mechanisms and the extent of subsurface damage in enamel produced during clinical tooth preparation. The aim of this study, therefore, was to investigate the mechanisms of subsurface damage produced in enamel during tooth preparation by means of diamond burs, and to examine the dependence of such damage on enamel rod orientation, diamond particle size, and removal rate. Subsurface damage was evaluated by a bonded-interface technique. Tooth preparation was carried out on two enamel rod orientations, with four clinical diamond burs (coarse, medium, fine, and superfine) used in a dental handpiece. The results of this study showed that subsurface damage in enamel took the form of median-type cracks and distributed microcracks, extending preferentially along the boundaries between the enamel rods. Microcracks within individual enamel rods were also observed. The median-type cracks were significantly longer in the direction parallel to the enamel rods than perpendicular to the rods. Preparation with the coarse diamond bur produced cracks as deep as 84 +/- 30 microns in enamel. Finishing with fine diamond burs was effective in crack removal. The crack lengths in enamel were not significantly different when the removal rate was varied. Based on these results, it is concluded that subsurface damage in enamel induced by tooth preparation takes the form of median-type cracks as well as inter- and intra-rod microcracks, and that the lengths of these cracks are sensitive to diamond particle size and enamel rod orientation, but insensitive to removal rate.

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

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.

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.

Carbon tetrachloride ERA soil-gas baseline monitoring

International Nuclear Information System (INIS)

Fancher, J.D.

1994-01-01

From December 1991 through December 1993, Westinghouse Hanford Company performed routine baseline monitoring of selected wells ad soil-gas points twice weekly in the 200 West Area of the Hanford Site. This work supported the carbon Tetrachloride Expedited Response Action (ERA) and provided a solid baseline of volatile organic compound (VOC) concentrations in wells and in the subsurface at the ERA site. As site remediation continues, comparisons to this baseline can be one means of measuring the success of carbon tetrachloride vapor extraction. This report contains observations of the patterns and trends associated with data obtained during soil-gas monitoring at the 200 West Area: Monitoring performed since late 1991 includes monitoring soil-gas probes ad wellheads for volatile organic compounds (VOCs). This report reflects monitoring data collected from December 1991 through December 1993

2011 Groundwater Monitoring and Inspection Report Gnome-Coach Site, New Mexico

International Nuclear Information System (INIS)

2012-01-01

Gnome-Coach was the site of a 3-kiloton underground nuclear test in 1961. Surface and subsurface contamination resulted from the underground nuclear testing, post-test drilling, and groundwater tracer test performed at the site. The State of New Mexico is currently proceeding with a conditional certificate of completion for the surface. As for the subsurface, monitoring activities that include hydraulic head monitoring and groundwater sampling of the wells onsite are conducted as part of the annual site inspection. These activities were conducted on January 19, 2011. The site roads, monitoring well heads, and the monument at surface ground zero were observed as being in good condition at the time of the site inspection. An evaluation of the hydraulic head data obtained from the site indicates that water levels in wells USGS-4 and USGS-8 appear to respond to the on/off cycling of the dedicated pump in well USGS-1 and that water levels in wells LRL-7 and DD-1 increased during this annual monitoring period. Analytical results obtained from the sampling indicate that concentrations of tritium, strontium-90, and cesium-137 were consistent with concentrations from historical sampling events.

2011 Groundwater Monitoring and Inspection Report Gnome-Coach Site, New Mexico

Energy Technology Data Exchange (ETDEWEB)

None

2012-02-01

Gnome-Coach was the site of a 3-kiloton underground nuclear test in 1961. Surface and subsurface contamination resulted from the underground nuclear testing, post-test drilling, and groundwater tracer test performed at the site. The State of New Mexico is currently proceeding with a conditional certificate of completion for the surface. As for the subsurface, monitoring activities that include hydraulic head monitoring and groundwater sampling of the wells onsite are conducted as part of the annual site inspection. These activities were conducted on January 19, 2011. The site roads, monitoring well heads, and the monument at surface ground zero were observed as being in good condition at the time of the site inspection. An evaluation of the hydraulic head data obtained from the site indicates that water levels in wells USGS-4 and USGS-8 appear to respond to the on/off cycling of the dedicated pump in well USGS-1 and that water levels in wells LRL-7 and DD-1 increased during this annual monitoring period. Analytical results obtained from the sampling indicate that concentrations of tritium, strontium-90, and cesium-137 were consistent with concentrations from historical sampling events.

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.

Imaging subsurface geology and volatile organic compound plumes

International Nuclear Information System (INIS)

Qualheim, B.J.; Daley, P.F.; Johnson, V.; McPherrin, R.V.; Laguna, G.

1992-03-01

Lawrence Livermore National Laboratory (LLNL) (Fig. 1) is in the final stages of the Superfund decisionmaking process for site remediation and restoration. In the process of characterizing the subsurface of the LLNL site, we have developed unique methods of collecting, storing, retrieving, and imaging geologic and chemical data from more than 350 drill holes. The lateral and vertical continuity of subsurface paleostream channels were mapped for the entire LLNL site using geologic descriptions from core samples, cuttings, and interpretations from geophysical logs. A computer-aided design and drafting program, SLICE, written at LLNL, was used to create two-dimensional maps of subsurface sediments, and state-of-the-art software produced three-dimensional images of the volatile organic compound (VOC) plumes using data from water and core fluid analyses

A bioenergetics-kinetics coupled modeling study on subsurface microbial metabolism in a field biostimulation experiment

Science.gov (United States)

Jin, Q.; Zheng, Z.; Zhu, C.

2006-12-01

Microorganisms in nature conserve energy by catalyzing various geochemical reactions. To build a quantitative relationship between geochemical conditions and metabolic rates, we propose a bioenergetics-kinetics coupled modeling approach. This approach describes microbial community as a metabolic network, i.e., fermenting microbes degrade organic substrates while aerobic respirer, nitrate reducer, metal reducer, sulfate reducer, and methanogen consume the fermentation products. It quantifies the control of substrate availability and biological energy conservation on the metabolic rates using thermodynamically consistent rate laws. We applied this simulation approach to study the progress of microbial metabolism during a field biostimulation experiment conducted in Oak Ridge, Tennessee. In the experiment, ethanol was injected into a monitoring well and groundwater was sampled to monitor changes in the chemistry. With time, concentrations of ethanol and SO42- decreased while those of NH4+, Fe2+, and Mn2+ increased. The simulation results fitted well to the observation, indicating simultaneous ethanol degradation and terminal electron accepting processes. The rates of aerobic respiration and denitrification were mainly controlled by substrate concentrations while those of ethanol degradation, sulfate reduction, and methanogenesis were controlled dominantly by the energy availability. The simulation results suggested two different microbial growth statuses in the subsurface. For the functional groups with significant growth, variations with time in substrate concentrations demonstrated a typical S curve. For the groups without significant growth, initial decreases in substrate concentrations were linear with time. Injecting substrates followed by monitoring environmental chemistry therefore provides a convenient approach to characterize microbial growth in the subsurface where methods for direct observation are currently unavailable. This research was funded by the

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.

Water and nitrogen requirements of subsurface drip irrigated pomegranate

Science.gov (United States)

Surface drip irrigation is a well-developed practice for both annual and perennial crops. The use of subsurface drip is a well-established practice in many annual row crops, e.g. tomatoes, strawberries, lettuce. However, the use of subsurface drip on perennial crops has been slow to develop. With th...

Subsurface chlorophyll maxima in the north-western Bay of Bengal