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Sample records for single-stage water sampling

  1. Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 95. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Childs, M.; Conrad, R.

    1997-09-01

    ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory (LANL) during FY 95 to characterize possible radionuclide movement out of Area G through surface water and entrained sediment runoff. Soil samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. The single-stage water samples were analyzed for tritium and plutonium isotopes. All radiochemical data was compared with analogous samples collected during FY 93 and 94 and reported in LA-12986 and LA-13165-PR. Six surface soils were also submitted for metal analyses. These data were included with similar data generated for soil samples collected during FY 94 and compared with metals in background samples collected at the Area G expansion area.

  2. Single-stage mass spectrometric analyses of resin bead samples

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D. H.; Walker, R. L.; Bertram, L. K.; Carter, J. A.

    1978-10-01

    Plutonium and uranium from dissolver solutions loaded on resin beads can be analyzed on single-stage mass spectrometers with little or no degradation of results provided proper care is exercised with regard to sample handling techniques. Additionally, storage of samples on resin beads is feasible for periods at least as long as six months provided the beads are not exposed to residual HNO/sub 3/ and air; it is probable that beads will retain their integrity much longer than six months when stored under collodion, but as yet no data to support this contention have been collected. Conventional or commercial mass spectrometers can readily be adapted to the resin bead technique by installing a pulse-counting detection system. The cost of such conversion will vary depending on whether or not a data acquisition system will be needed. A reasonable estimate is that the cost will be in the neighborhood of $15,000; this figure includes the price of a multi-channel analyzer to serve as a temporary data storage device, but does not include the cost of a computer. It does not appear that it will be practicable to switch easily back and forth between pulse-counting and current integration modes unless the instrument is provided with a movable Faraday cup. Using the same multiplier in both modes would undoubtedly degrade its performance in each. The requirements of low background counting rates and high gain for pulse counting, and of relatively high signal handling capacity in current integration are mutually incompatible if demanded of the same multiplier.

  3. Analysis of U and Pu resin bead samples with a single stage mass spectrometer

    International Nuclear Information System (INIS)

    Smith, D.H.; Walker, R.L.; Bertram, L.K.; Carter, J.A.

    1979-01-01

    Resin bead sampling enables the shipment of nanogram U and Pu quantities for analysis. Application of this sampling technique to safeguards was investigated with a single-stage mass spectrometer. Standards gave results in good agreement with NBS certified values. External precisions of +-0.5% were obtained on isotopic ratios of approx. 0.01; precisions on quantitative measurements are +-1.0%

  4. Simulation model of a single-stage lithium bromide-water absorption cooling unit

    Science.gov (United States)

    Miao, D.

    1978-01-01

    A computer model of a LiBr-H2O single-stage absorption machine was developed. The model, utilizing a given set of design data such as water-flow rates and inlet or outlet temperatures of these flow rates but without knowing the interior characteristics of the machine (heat transfer rates and surface areas), can be used to predict or simulate off-design performance. Results from 130 off-design cases for a given commercial machine agree with the published data within 2 percent.

  5. Studies on water turbine runner which fish can pass through: In case of single stage axial runner

    International Nuclear Information System (INIS)

    Shimizu, Yukimari; Maeda, Takao; Nagoshi, Osamu; Ieda, Kazuma; Shinma, Hisako; Hagimoto, Michiko

    1994-01-01

    The relationship between water turbine runner design and operation and the safe passage of fish through the turbine is studied. The kinds of fish used in the tests are a dace, a sweet fish and a small salmon. A single stage axial runner is used. The velocity and pressure distributions were measured inside the turbine casing and along the casing wall. Many pictures showing fish passing through the rotating runner were taken and analyzed. The swimming speed of the fish was examined from video recordings. Fish pass through the runner more rapidly when they can determine and choose the easier path. Injury and mortality of fish are affected by the runner speed and the location of impact of the runner on the fish body

  6. Single-stage oxidative dehydrogenation of n-butaneand isopentane in adiabatic sectional reactors with supply of oxygene and water steam

    International Nuclear Information System (INIS)

    Azizov, A.G; Gadji-Kasumov, V.S

    2000-01-01

    Full text: The advanced technique of single-stage dehydrogenation of n-butane and iso-pentane in adiabatic sectional with separate supply of oxygen on every section is offered. The substance of the novel method consist in water metering for every section. Such technological technique considerably cut the specific energy expenses on high temperature water steam production, increase the yield and selectivity of main products formation at the expense of more complete partial oxidation of the correspondend olefins.

  7. Performance analysis of the single-stage absorption heat transformer using a new working pair composed of ionic liquid and water

    International Nuclear Information System (INIS)

    Zhang Xiaodong; Hu Dapeng

    2012-01-01

    The performance simulation of a single-stage absorption heat transformer using a new working pair composed of ionic liquids, 1-ethyl-3-methylimidazolium dimethylphosphate, and water (H 2 O + [EMIM][DMP]), was performed based on the thermodynamic properties of the new working pair and on the mass and energy balance for each component of the system. In order to evaluate the new working pair, the simulation results were compared with those of aqueous solution of lithium bromide (H 2 O + LiBr), Trifluoroethanol (TFE) + tetraethylenglycol dimethylether (E181). The results indicate that when generation, evaporation, condensing and absorption temperatures are 90 °C, 90 °C, 35 °C and 130 °C, the coefficients of performance of the single-stage absorption heat transformer using H 2 O + LiBr, H 2 O + [EMIM][DMP] and TFE + E181 as working pairs will reach 0.494, 0.481 and 0.458 respectively. And the corresponding exergy efficiency will reach 0.64, 0.62 and 0.59, respectively. Meanwhile the available heat outputs for per unit mass of refrigerant are 2466 kJ/kg, 2344 kJ/kg and 311 kJ/kg, respectively. The above excellent cycle performance together with the advantages of negligible vapor pressure, no crystallization and more weak corrosion tendency to iron-steel materials may make the new working pair better suited for the industrial absorption heat transformer. - Highlights: ► The cycle performance of the single-stage absorption heat transformer was simulated. ► Water and 1-ethyl-3-methylimidazolium dimethylphosphate was used as new working pair. ► Water and 1-ethyl-3-methylimidazolium dimethylphosphate are entirely miscible. ► The COP and exergy efficiency for this new working pairs were 0.481 and 0.62. ► The new working pairs has potential application to absorption heat transformer.

  8. Characteristics and Sampling Efficiencies of Two Impactor Bioaerosol Samplers: MAS-100(Registered) (Microbial Air Monitoring System) and Single-Stage Andersen Viable Microbial Samplers

    National Research Council Canada - National Science Library

    Hottell, K

    2004-01-01

    .... A petri dish with agar is used as the impaction surface for these samplers. The MAS-l00 is a single-stage impactor that aspirates air through a 400-hole perforated entry plate onto an agar plate at an airflow rate of 100 L/min...

  9. Performance analysis of single stage libr-water absorption machine operated by waste thermal energy of internal combustion engine: Case study

    Science.gov (United States)

    Sharif, Hafiz Zafar; Leman, A. M.; Muthuraman, S.; Salleh, Mohd Najib Mohd; Zakaria, Supaat

    2017-09-01

    Combined heating, cooling, and power is also known as Tri-generation. Tri-generation system can provide power, hot water, space heating and air -conditioning from single source of energy. The objective of this study is to propose a method to evaluate the characteristic and performance of a single stage lithium bromide-water (LiBr-H2O) absorption machine operated with waste thermal energy of internal combustion engine which is integral part of trigeneration system. Correlations for computer sensitivity analysis are developed in data fit software for (P-T-X), (H-T-X), saturated liquid (water), saturated vapor, saturation pressure and crystallization temperature curve of LiBr-H2O Solution. Number of equations were developed with data fit software and exported into excel work sheet for the evaluation of number of parameter concerned with the performance of vapor absorption machine such as co-efficient of performance, concentration of solution, mass flow rate, size of heat exchangers of the unit in relation to the generator, condenser, absorber and evaporator temperatures. Size of vapor absorption machine within its crystallization limits for cooling and heating by waste energy recovered from exhaust gas, and jacket water of internal combustion engine also presented in this study to save the time and cost for the facilities managers who are interested to utilize the waste thermal energy of their buildings or premises for heating and air conditioning applications.

  10. Exergy analysis of an experimental single-stage heat transformer operating with single water/lithium bromide and using additives (1-octanol and 2-ethyl-1-hexanol)

    International Nuclear Information System (INIS)

    Rivera, W.; Martinez, H.; Cerezo, J.; Romero, R.J.; Cardoso, M.J.

    2011-01-01

    Second law of Thermodynamics has been used to analyze the performance of an experimental single-stage heat transformer operating with the water/lithium bromide as single working pair and subsequently, using 1-octanol and 2-ethyl-1-hexanol as additives. Additives have been used in order to increase the heat transfer in the absorber and generator decreasing their irreversibilities. The enthalpy-based coefficients of performance (COP), external coefficients of performance (COP EXT ), exergy-based coefficients of performance (ECOP) and the irreversibilities of the equipment components were calculated for the main operating temperatures of the system. The results showed that for absorber temperatures between 84 o C and 88 o C the highest COP, COP EXT , and ECOP are obtained with the use of the 2-ethyl-1-hexanol (400 parts per million) additive, reaching values up to 0.49, 0.40 and 0.43, respectively. The lowest coefficients of performance and highest irreversibilities were obtained by using the single water/lithium bromide mixture. Analysing the irreversibilities in each one of the main components of the system, it was found that 2-ethyl-1-hexanol decreases considerably the irreversibility in the absorber then increasing the efficiency of this component and hence of the entire equipment. - Highlights: → An exergy analysis has been used to analyze an experimental heat transformer. → The system operated with single water/lithium bromide and then adding two additives. → The additives were 1-octanol and 2-ethyl-1-hexanol. → The 2-ethyl-1-hexanol additive reduced the system irreversibilities. → The highest coefficients of performance were obtained with the 2-ethyl-1-hexanol additive.

  11. A single-stage functionalization and exfoliation method for the production of graphene in water: stepwise construction of 2D-nanostructured composites with iron oxide nanoparticles.

    Science.gov (United States)

    Ihiawakrim, Dris; Ersen, Ovidiu; Melin, Frédéric; Hellwig, Petra; Janowska, Izabela; Begin, Dominique; Baaziz, Walid; Begin-Colin, Sylvie; Pham-Huu, Cuong; Baati, Rachid

    2013-10-07

    A practically simple top-down process for the exfoliation of graphene (GN) and few-layer graphene (FLG) from graphite is described. We have discovered that a biocompatible amphiphilic pyrene-based hexahistidine peptide is able to exfoliate, functionalize, and dissolve few layer graphene flakes in pure water under exceptionally mild, sustainable and virtually innocuous low intensity cavitation conditions. Large area functionalized graphene flakes with the hexahistidine oligopeptide (His₆-TagGN = His₆@GN) have been produced efficiently at room temperature and characterized by TEM, Raman, and UV spectroscopy. Conductivity experiments carried out on His₆-TagGN samples revealed superior electric performances as compared to reduced graphene oxide (rGO) and non-functionalized graphene, demonstrating the non-invasive features of our non-covalent functionalization process. We postulated a rational exfoliation mechanism based on the intercalation of the peptide amphiphile under cavitational chemistry. We also demonstrated the ability of His6-TagGN nanoassemblies to self-assemble spontaneously with inorganic iron oxide nanoparticles generating magnetic two-dimensional (2D) His₆-TagGN/Fe₃O₄ nanocomposites under mild and non-hydrothermal conditions. The set of original experiments described here open novel perspectives in the facile production of water dispersible high quality GN and FLG sheets that will improve and facilitate the interfacing, processing and manipulation of graphene for promising applications in catalysis, nanocomposite construction, integrated nanoelectronic devices and bionanotechnology.

  12. Developing Water Sampling Standards

    Science.gov (United States)

    Environmental Science and Technology, 1974

    1974-01-01

    Participants in the D-19 symposium on aquatic sampling and measurement for water pollution assessment were informed that determining the extent of waste water stream pollution is not a cut and dry procedure. Topics discussed include field sampling, representative sampling from storm sewers, suggested sampler features and application of improved…

  13. A further step toward H2 in automobile : development of an efficient bi-functional catalyst for single stage water gas shift

    NARCIS (Netherlands)

    Azzam, K.G.H.

    2008-01-01

    The suitability of polymer electrolyte fuel (PEM) cells for stationary and vehicular applications initiated research in all areas of fuel processor (i.e. reformer, water-gas-shift, preferential oxidation of CO (PROX)) catalysts for hydrogen generation. Water gas shift (WGS) reaction is an essential

  14. Design, Construction and Measured Performance of a Single-Stage ...

    African Journals Online (AJOL)

    The design philosophy, construction and measured performances of a single stage, single entry centrifugal pump demonstration unit are presented. In the construction, close-coupled induction motor drives the centrifugal pump, which draws fluid (water) from a water storage tank and delivers same through a flow control ...

  15. Reactor water sampling device

    International Nuclear Information System (INIS)

    Sakamaki, Kazuo.

    1992-01-01

    The present invention concerns a reactor water sampling device for sampling reactor water in an in-core monitor (neutron measuring tube) housing in a BWR type reactor. The upper end portion of a drain pipe of the reactor water sampling device is attached detachably to an in-core monitor flange. A push-up rod is inserted in the drain pipe vertically movably. A sampling vessel and a vacuum pump are connected to the lower end of the drain pipe. A vacuum pump is operated to depressurize the inside of the device and move the push-up rod upwardly. Reactor water in the in-core monitor housing flows between the drain pipe and the push-up rod and flows into the sampling vessel. With such a constitution, reactor water in the in-core monitor housing can be sampled rapidly with neither opening the lid of the reactor pressure vessel nor being in contact with air. Accordingly, operator's exposure dose can be reduced. (I.N.)

  16. Delayed Single Stage Perineal Posterior Urethroplasty

    International Nuclear Information System (INIS)

    Ali, S.; Shahnawaz; Shahzad, I.; Baloch, M. U.

    2015-01-01

    Objective: To determine the delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture/distraction defect. Study Design: Descriptive case series. Place and Duration of Study: Department of Urology, Jinnah Postgraduate Medical Centre, Karachi, from January 2009 to December 2011. Methodology: Patients were selected for delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture / distraction defect. All were initially suprapubically catheterized followed by definitive surgery after at least 3 months. Results: Thirty male patients were analyzed with a mean follow-up of 10 months, 2 patients were excluded as they developed failure in first 3 months postoperatively. Mean patients age was 26.25 ± 7.9 years. On follow-up, 7 patients (23.3 percentage) experienced recurrent stricture during first 10 months. Five (16.6 percentage) patients were treated successfully with single direct visual internal urethrotomy. Two patients (6.6 percentage) had more than one direct visual internal urethrotomy and considered failed. Re-do perineal urethroplasty was eventually performed. The overall success rate was 93.3 percentage with permissive criteria allowing single direct visual internal urethrotomy and 76.6% with strict criteria allowing no more procedures postoperatively. Conclusion: Posterior anastomotic urethroplasty offers excellent long-term results to patients with posterior urethral trauma and distraction defect even after multiple prior procedures. (author)

  17. New results for single stage low energy carbon AMS

    International Nuclear Information System (INIS)

    Klody, G.M.; Schroeder, J.B.; Norton, G.A.; Loger, R.L.; Kitchen, R.L.; Sundquist, M.L.

    2005-01-01

    A new configuration of the NEC single stage, low energy carbon AMS system (U.S. Patent 6,815,666 B2) has been built and tested. The injector includes two 40-sample ion sources, electrostatic and magnetic analysis, and fast sequential injection. The gas stripper, analyzing magnet, electrostatic analyzer, and detector are on an open air 250 kV deck. Both 12 C and 13 C currents are measured on the deck after the stripper, and an SSB detector is used for 14 C counting. Injected 12 C and mass 13 ( 13 C and 12 CH) currents are also measured. Automated controls follow a user-specified run list for unattended operation. Initial test results show precision for 14 C/ 12 C ratios of better than 5 per mil, and backgrounds for unprocessed graphite of less than 0.005 x modern. We will report final results for precision, background, and throughput and discuss related design features

  18. Validation of a PC based program for single stage absorption heat pump

    Science.gov (United States)

    Zaltash, A.; Ally, M. R.

    1991-09-01

    An interactive computer code was developed to evaluate single stage absorption heat pump performance for temperature amplifier and heat amplifier modes using water as the refrigerant. This program performs the cycle calculations for single stage cycles based on the polynomial expressions developed to correlate experimental vapor-liquid-equilibrium (VLE) and specific enthalpy-concentration data for LiBr/water and (Li, K, Na)NO3 water systems as well as the properties of pure water. The operating parameters obtained by this program were tested against mass and energy balances in documented cases and the results show that the maximum deviation between coefficient of performance (COP) values obtained by this software and the ones previously calculated is less than 3 percent. In addition, this program was used to study the effect of solution temperature leaving the absorber on the other operating parameters. This type of analysis could be used to improve and optimize cycle design.

  19. Single-stage repair versus traditional repair of high anorectal ...

    African Journals Online (AJOL)

    random number table. The patients in group A were treated with a single-stage operation, whereas the patients in group B were treated with a standard staged operation. (either PSARP or abdominoperineal pull-through). After clinical evaluation using the Kelly score, patients were divided into three clinical groups ...

  20. Control of Single-Stage Single-Phase PV inverter

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Teodorescu, Remus; Blaabjerg, Frede

    2005-01-01

    In this paper the issue of control strategies for single-stage photovoltaic (PV) inverter is addressed. Two different current controllers have been implemented and an experimental comparison between them has been made. A complete control structure for the single-phase PV system is also presented...

  1. Radon measurement in Malaysia water samples

    International Nuclear Information System (INIS)

    Ibrahim, A.B.; Rosli Mahat; Yusof Md Amin

    1995-01-01

    This paper reported the results of the measurement of radon in local water. The water samples collected were rainwater, river water, seawater, well water or ground water at area of State of Selangor and Kuala Lumpur. The samples were collected in scintillation cell ZnS(Ag) through Radon Degassing Unit RDU 200. Alpha activity was counted with scintillation counters RD 200 at energy 5.5 MeV. (author)

  2. Magnificent Ground Water Connection. [Sample Activities].

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    Water conservation and usage is an important concept in science. This document, geared specifically to New England, provides many activities for protecting and discussing ground water situations. Sample activities for grades K-6 include: (1) All the Water in the World; (2) The Case of the Disappearing Water; (3) Deep Subjects--Wells and Ground…

  3. Water sample-collection and distribution system

    Science.gov (United States)

    Brooks, R. R.

    1978-01-01

    Collection and distribution system samples water from six designated stations, filtered if desired, and delivers it to various analytical sensors. System may be controlled by Water Monitoring Data Acquisition System or operated manually.

  4. Nitrite reduction and methanogenesis in a single-stage UASB reactor.

    Science.gov (United States)

    Borges, L I; López-Vazquez, C M; García, H; van Lier, J B

    2015-01-01

    In this study, nitrite reduction and methanogenesis in a single-stage upflow anaerobic sludge blanket (UASB) reactor was investigated, using high-strength synthetic domestic wastewater as substrate. To assess long-term effects and evaluate the mechanisms that allow successful nitrite reduction and methanogenesis in a single-stage UASB, sludge was exposed to relatively high nitrite loading rates (315 ± 13 mgNO(2)(-)-N/(l.d)), using a chemical oxygen demand (COD) to nitrogen ratio of 18 gCOD/gNO(2)(-)-N, and an organic loading rate of 5.4 ± 0.2 gCOD/(l.d). In parallel, the effects of sludge morphology on methanogenesis inhibition were studied by performing short-term batch activity tests at different COD/NO(2)(-)-N ratios with anaerobic sludge samples. In long-term tests, denitrification was practically complete and COD removal efficiency did not change significantly after nitrite addition. Furthermore, methane production only decreased by 13%, agreeing with the reducing equivalents requirement for complete NO(2)(-) reduction to N₂. Apparently, the spatial separation of denitrification and methanogenesis zones inside the UASB reactor allowed nitrite reduction and methanogenesis to occur at the same moment. Batch tests showed that granules seem to protect methanogens from nitrite inhibition, probably due to transport limitations. Combined COD and N removal via nitrite in a single-stage UASB reactor could be a feasible technology to treat high-strength domestic wastewater.

  5. Control of Single-Stage Single-Phase PV inverter

    DEFF Research Database (Denmark)

    Ciobotaru, Mihai; Teodorescu, Remus; Blaabjerg, Frede

    2005-01-01

    In this paper the issue of control strategies for single-stage photovoltaic (PV) inverter is addressed. Two different current controllers have been implemented and an experimental comparison between them has been made. A complete control structure for the single-phase PV system is also presented......-forward; - and the grid current controller implemented in two different ways, using the classical proportional integral (PI) and the novel proportional resonant (PR) controllers. The control strategy was tested experimentally on 1.5 kW PV inverter........ The main elements of the PV control structure are: - a maximum power point tracker (MPPT) algorithm using the incremental conductance method; - a synchronization method using the phase-locked-loop (PLL), based on delay; - the input power control using the dc voltage controller and power feed...

  6. Water Sample Points, Navajo Nation, 2000, USACE

    Data.gov (United States)

    U.S. Environmental Protection Agency — This point shapefile presents the locations and results for water samples collected on the Navajo Nation by the US Army Corps of Engineers (USACE) for the US...

  7. Water sampling techniques for continuous monitoring of pesticides in water

    Directory of Open Access Journals (Sweden)

    Šunjka Dragana

    2017-01-01

    Full Text Available Good ecological and chemical status of water represents the most important aim of the Water Framework Directive 2000/60/EC, which implies respect of water quality standards at the level of entire river basin (2008/105/EC and 2013/39/EC. This especially refers to the control of pesticide residues in surface waters. In order to achieve the set goals, a continuous monitoring program that should provide a comprehensive and interrelated overview of water status should be implemented. However, it demands the use of appropriate analysis techniques. Until now, the procedure for sampling and quantification of residual pesticide quantities in aquatic environment was based on the use of traditional sampling techniques that imply periodical collecting of individual samples. However, this type of sampling provides only a snapshot of the situation in regard to the presence of pollutants in water. As an alternative, the technique of passive sampling of pollutants in water, including pesticides has been introduced. Different samplers are available for pesticide sampling in surface water, depending on compounds. The technique itself is based on keeping a device in water over a longer period of time which varies from several days to several weeks, depending on the kind of compound. In this manner, the average concentrations of pollutants dissolved in water during a time period (time-weighted average concentrations, TWA are obtained, which enables monitoring of trends in areal and seasonal variations. The use of these techniques also leads to an increase in sensitivity of analytical methods, considering that pre-concentration of analytes takes place within the sorption medium. However, the use of these techniques for determination of pesticide concentrations in real water environments requires calibration studies for the estimation of sampling rates (Rs. Rs is a volume of water per time, calculated as the product of overall mass transfer coefficient and area of

  8. NASA Glenn's Single-Stage Axial Compressor Facility Upgraded

    Science.gov (United States)

    Brokopp, Richard A.

    2004-01-01

    NASA Glenn Research Center's Single-Stage Axial Compressor Facility was upgraded in fiscal year 2003 to expand and improve its research capabilities for testing high-speed fans and compressors. The old 3000-hp drive motor and gearbox were removed and replaced with a refurbished 7000-hp drive motor and gearbox, with a maximum output speed of 21,240 rpm. The higher horsepower rating permits testing of fans and compressors with higher pressure ratio or higher flow. A new inline torquemeter was installed to provide an alternate measurement of fan and compressor efficiency, along with the standard pressure and temperature measurements. A refurbished compressor bearing housing was also installed with bidirectional rotation capability, so that a variety of existing hardware could be tested. Four new lubrication modules with backup capability were installed for the motor, gearbox, torquemeter, and compressor bearing housing, so that in case the primary pump fails, the backup will prevent damage to the rotating hardware. The combustion air supply line for the facility inlet air system was activated to provide dry air for repeatable inlet conditions. New flow conditioning hardware was installed in the facility inlet plenum tank, which greatly reduced the inlet turbulence. The new inlet can also be easily modified to accommodate 20- or 22-in.-diameter fans and compressors, so a variety of existing hardware from other facilities (such as Glenn's 9- by 15-Foot Low-Speed Wind Tunnel) can be tested in the Single-Stage Axial Compressor Facility. An exhaust line was also installed to provide bleed capability to remove the inlet boundary layer. To improve the operation and control of the facility, a new programmable logic controller (PLC) was installed to upgrade from hardwired relay logic to software logic. The PLC also enabled the usage of human-machine interface software to allow for easier operation of the facility and easier reconfiguration of the facility controls when

  9. physico-chemical properties of well water samples from some

    African Journals Online (AJOL)

    Administrator

    chemical causes changes to the quality of the receiving water body. (Aremu et ... Sample collection, treatment and preservation: Water samples ... DEVIATION VALUES OF PHYSICO-CHEMICAL PARAMETERS OF. THE WELL WATER SAMPLES COMPARED WITH WHO STANDARD FOR DRINKING WATER. PARAMETER.

  10. Monte Carlo Error Analysis Applied to Core Formation: The Single-stage Model Revived

    Science.gov (United States)

    Cottrell, E.; Walter, M. J.

    2009-12-01

    The last decade has witnessed an explosion of studies that scrutinize whether or not the siderophile element budget of the modern mantle can plausibly be explained by metal-silicate equilibration in a deep magma ocean during core formation. The single-stage equilibrium scenario is seductive because experiments that equilibrate metal and silicate can then serve as a proxy for the early earth, and the physical and chemical conditions of core formation can be identified. Recently, models have become more complex as they try to accommodate the proliferation of element partitioning data sets, each of which sets its own limits on the pressure, temperature, and chemistry of equilibration. The ability of single stage models to explain mantle chemistry has subsequently been challenged, resulting in the development of complex multi-stage core formation models. Here we show that the extent to which extant partitioning data are consistent with single-stage core formation depends heavily upon (1) the assumptions made when regressing experimental partitioning data (2) the certainty with which regression coefficients are known and (3) the certainty with which the core/mantle concentration ratios of the siderophile elements are known. We introduce a Monte Carlo algorithm coded in MATLAB that samples parameter space in pressure and oxygen fugacity for a given mantle composition (nbo/t) and liquidus, and returns the number of equilibrium single-stage liquidus “solutions” that are permissible, taking into account the uncertainty in regression parameters and range of acceptable core/mantle ratios. Here we explore the consequences of regression parameter uncertainty and the impact of regression construction on model outcomes. We find that the form of the partition coefficient (Kd with enforced valence state, or D) and the handling of the temperature effect (based on 1-atm free energy data or high P-T experimental observations) critically affects model outcomes. We consider the most

  11. Single Stage Contactor Testing Of The Next Generation Solvent Blend

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D. T.; Peters, T. B.; Duignan, M. R.; Williams, M. R.; Poirier, M. R.; Brass, E. A.; Garrison, A. G.; Ketusky, E. T.

    2014-01-06

    The Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) facility at the Savannah River Site (SRS) is actively pursuing the transition from the current BOBCalixC6 based solvent to the Next Generation Solvent (NGS)-MCU solvent to increase the cesium decontamination factor. To support this integration of NGS into the MCU facility the Savannah River National Laboratory (SRNL) performed testing of a blend of the NGS (MaxCalix based solvent) with the current solvent (BOBCalixC6 based solvent) for the removal of cesium (Cs) from the liquid salt waste stream. This testing utilized a blend of BOBCalixC6 based solvent and the NGS with the new extractant, MaxCalix, as well as a new suppressor, tris(3,7dimethyloctyl) guanidine. Single stage tests were conducted using the full size V-05 and V-10 liquid-to-liquid centrifugal contactors installed at SRNL. These tests were designed to determine the mass transfer and hydraulic characteristics with the NGS solvent blended with the projected heel of the BOBCalixC6 based solvent that will exist in MCU at time of transition. The test program evaluated the amount of organic carryover and the droplet size of the organic carryover phases using several analytical methods. The results indicate that hydraulically, the NGS solvent performed hydraulically similar to the current solvent which was expected. For the organic carryover 93% of the solvent is predicted to be recovered from the stripping operation and 96% from the extraction operation. As for the mass transfer, the NGS solvent significantly improved the cesium DF by at least an order of magnitude when extrapolating the One-stage results to actual Seven-stage extraction operation with a stage efficiency of 95%.

  12. Water sampling device for detecting fuel failure

    International Nuclear Information System (INIS)

    Masubuchi, Yukio.

    1997-01-01

    A notched portion is formed at the lower end of an outer cap, and an extensible air bag is disposed being in contact with the inner side of the notched portion. A compressed air is sent into the outer gap through an air supply pipe to urge coolants thereby lowering the water level. A portion of the compressed air gets out of the outer gap from the notched portion, and if air bubbles are observed on the surface of coolants in a pressure vessel of a reactor, the outer cap is confirmed to be attached to the upper lattice plate. Compressed air is supplied to the air bag to close the notched portion. Then, coolants are sucked from a water level confirmation pipe. The level of coolants is further lowered, and the compressed air is sucked from the water level confirmation pipe instead of the coolants. Then, the level of the coolants at the inner side of the inner cap is confirmed to be made lower than the upper end of the channel box of a reactor fuel assembly. Then, coolants in the channel box are sampled, as a specimen water, through a water sampling pipe. (I.N.)

  13. Determination of 40K in water samples

    International Nuclear Information System (INIS)

    Delgado, C. E.; Miranda C, L.; Cuevas J, A. K.; Vega C, H. R.

    2014-10-01

    The natural water used for human consumption comes from different sources, which may contain suspended solids in varying proportions. In groundwater, the source of suspended solids is related to the dissolution of mineral strata by the waters and leaching of rocks. Also, the radioactivity could concentrate on the bodies of slow-moving water that eventually could present a risk to ecosystems, as well as for the consumer. The water usually contains several natural radionuclides as: tritium, radon, radio, uranium isotopes, etc. The objective of this study was to evaluate the concentration of 40 K in water from different areas of Zacatecas state (Mexico). Four water samples were taken in triplicate from different areas; the 40 K concentration was measured with a spectrum metric system of gamma radiation with NaI (Tl) scintillation detector of 7.62 cm. In the measuring process a standard was prepared using water and KCl analytic grade where the 40 K concentration is 6.25 mol/Lt adding 250 mg/ml of potassium. Also the system was calibrated in energy using 3 point sources of 137 Cs, diameter 22 Na and 7.62 cm of height, using containers Marinelli and 60 Co. In the obtained spectra was observed that the photon of 1.432 MeV that emits the 40 K when decaying is the most important. The highest concentration was of 123 ± 5.2 Bq/lt and the lowest was of 9 ± 0.4 Bq/lt. Under the standards of drinking water, an amount of 40 K deposits an effective dose which contributes to annual dose received by people. (Author)

  14. PIXE analysis applied to characterized water samples

    International Nuclear Information System (INIS)

    Santos, Maristela S.; Carneiro, Luana Gomes; Medeiros, Geiza; Sampaio, Camilla; Martorell, Ana Beatriz Targino; Gouvea, Stella; Cunha, Kenya Moore Dias da

    2011-01-01

    Araxa, in Brazil, is a naturally high background area located in the State of Minas Gerais with a population of about 93 672 people. Araxa is historical city famous for its mineral water sources and mud from Termas de Araxa spa, which have been used for therapeutic, and recreation purposes. Other important aspect of economy of the city are mining and metallurgic industries. In the Araxa area is located the largest deposit of pyrochlore, a niobium mineral, and also a deposit of apatite, a phosphate mineral both containing Th and U associated to crystal lattice. The minerals are obtained from open pit mines, the minerals are processed in industrial also located in city of Araxa, these plants process the pyrochlore and apatite to obtain the Fe-Nb alloy and the concentrate of phosphate, respectively. Studies were developed in this area to assessment the occupational risk of the workers due to exposure to dust particles during the routine working, however very few studies evaluated the water contamination outside the mines in order to determine the metal (stables elements) concentrations in water and also the concentrations of the radionuclides in water. This paper presents the previous results of a study to identify and determine the concentrations of metals (stables elements) and radionuclides in river around the city. The water from these rivers is used as drinking water and irrigation water. The water samples were collected in different rivers around the Araxa city and the samples were analyzed using PIXE technique. A proton beam of 2 MeV obtained from the van de Graaff electrostatic accelerator was used to induce the characteristic X-rays. S, K, Ca, Cr, Mn, Fe, Ni, Zn, Ba, Pb and U were identified in the mass spectrum of the samples. The elemental mass concentrations were compared using a non-parametric statistical test. The results of the statistical test showed that the elemental mass concentrations did not present the same distribution. These results indicated

  15. Aeration Strategies To Mitigate Nitrous Oxide Emissions from Single-Stage Nitritation/Anammox Reactors

    DEFF Research Database (Denmark)

    Domingo Felez, Carlos; Mutlu, A. Gizem; Jensen, Marlene Mark

    2014-01-01

    Autotrophic nitrogen removal is regarded as a resource efficient process to manage nitrogen-rich residual streams. However, nitrous oxide emissions of these processes are poorly documented and strategies to mitigate emissions unknown. In this study, two sequencing batch reactors performing single......-stage nitritation/anammox were operated under different aeration strategies, gradually adjusted over six months. At constant but limiting oxygen loading, synthetic reject water was fed (0.75g-N/L.d) and high nitrogen removal efficiencies (83 +/- 5 and 88 +/- 2%) obtained. Dynamics of liquid phase nitrous (N2O......) and nitric oxide (NO) concentrations were monitored and N2O emissions calculated. Significant decreases in N2O emissions were obtained when the frequency of aeration was increased while maintaining a constant air flow rate (from >6 to 1.7% Delta N2O/Delta TN). However, no significant effect on the emissions...

  16. Investigative studies on water contamination in Bangladesh. Primary treatment of water samples at the sampling site

    International Nuclear Information System (INIS)

    Sera, K.; Islam, Md. Shafiqul; Takatsuji, T.; Nakamura, T.; Goto, S.; Takahashi, C.; Saitoh, Y.

    2010-01-01

    Arsenic concentration in 13 well waters, 9 pond waters, 10 agricultural waters and a coconut juice taken in Comilla district, Bangladesh, where the problem of arsenic pollution is the most severe, was investigated. High-level arsenic is detected even in the well water which has been kept drinking by the people. Relatively high arsenic concentration was detected for some pond and farm waters even though the sampling was performed just after the rainy season and the waters were expected to be highly diluted. Clear relationship was observed in elemental compositions between the pond water and the coconut juice collected at the edge of the water. These results are expected to become the basic information for evaluating the risk of individual food such as cultured fishes, shrimps and farm products, and for controlling total intakes of arsenic. In order to solve the problem of transportation of water samples internationally, a simple method of target preparation performed at the sampling site was established and its validity was confirmed. All targets were prepared at the sampling sites in this study on the basis of this method. (author)

  17. Single-stage accelerator mass spectrometer radiocarbon-interference identification and positive-ionisation characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Wilcken, K.M., E-mail: klaus.wilcken@ansto.gov.au [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom); Freeman, S.P.H.T.; Xu, S.; Dougans, A. [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom)

    2013-01-15

    A single-stage accelerator mass spectrometer (SSAMS) is a good alternative to conventional spectrometers based on tandem electrostatic acceleration for radiocarbon measurement and permits experimentation with both negative and positive carbon ions. However, such {sup 14}C AMS of either polarity ions is limited by an interference. In the case of anion acceleration we have newly determined this to be summed {sup 13}C and {sup 16}O by improvising an additional Wien filter on our SSAMS deck. Also, {sup 14}C AMS might be improved by removing its dependency on negative-ionisation in a sputter ion source. This requires negative-ionisation of sample atoms elsewhere to suppress the {sup 14}N interference, which we accomplish by transmitting initially positive ions through a thin membrane. The ionisation dependence on ion-energy is found to be consistent with previous experimentation with vapours and thicker foils.

  18. design, construction and measured performance of a single-stage

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Piezometers are attached to the pipe work, close to the inlet and outlet of the pump, so that the total head-rise (H), ... voir and pipe work for continuous water circulation is also provided. Manually operated valves, at the ... pump suction via a flexible tube. The two manome- ters have an external diameter of ...

  19. Theoretical comparison of single-stage and advanced absorption heat transformers used to increase solar pond's temperature

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, W; Best, Roberto [Centro de Investigacion en Energia-UNAM, Temixco, Morelos (Mexico)

    2000-07-01

    Mathematical models of single-stage and advanced absorption heat transformers operating with the water/Carrol{sup T}M mixture were developed to simulate the performance of these systems coupled to a solar pond in order to increase the temperature of the useful heat produced by solar ponds. The results showed that the single-stage and the double absorption heat transformer are the most promising configuration to be coupled to solar ponds. With single-stage heat transformers it is possible to increase solar pond's temperature until 50 Celsius degrees with coefficients of performance of about 0.48 and with double absorption heat transformers until 100 Celsius degrees with coefficients of performance of 0.33. [Spanish] Se desarrollaron modelos matematicos de una sola etapa y transformadores avanzados de absorcion de calor operando con la mezcla agua/Carrol{sup T}M para simular el rendimiento de estos sistemas acoplados a un estanque solar con el objeto de aumentar la temperatura del calor util producido por los estanques solares. Los resultados mostraron que la etapa sencilla y el transformador de calor de absorcion doble son la configuracion mas prometedora para ser acoplado a estanques solares. Con los transformadores de calor de una sola etapa es posible aumentar la temperatura del estanque solar hasta 50 grados Celsius con coeficientes de rendimiento de alrededor de 0.48 y con transformadores de calor de doble absorcion hasta 100 grados Celsius con coeficientes de rendimiento de 0.33.

  20. The running waters macroinvertebrates community: sampling techniques.

    Science.gov (United States)

    Baldaccini, Gilberto Natale; Leone, Laura Marianna; Taddei, Cinzia

    2009-04-01

    The community of running water macroinvertebrates has proved to be one of key subjects for fluvial ecology and bioindication studies, thanks both to the different trophic roles within the range of taxa and to the ease with which they may be collected and identified. However, the complex nature of this community creates problems concerning the complete identification of the full range of taxa, even when restricting the taxonomic classification to families and genera. Even so, the need to use the community for the implementation of indexes of Ecological Status of freshwaters and for the detection of reference conditions, necessarily means a deeper knowledge of this structure. Hence, a standard methodology of the capture effort is required to identify not only the ecological quality but also a reference community for each selected fluvial typology and for each section examined. Starting from the processing of data collected during intercalibration exercises of the IBE method, the authors analyse the results underlining the share given by the size of the sample collected (catchment effort), and by the distribution models of different taxa within the community, in order to give a contribution to the evaluation of the reliability level of standard samples. The results confirm the models already described in previous publications and lead us to accept the presence of marginal degrees of uncertainty in standard samples.

  1. Handbook for Sampling and Sample Preservation of Water and Wastewater

    Science.gov (United States)

    1992-05-01

    The group includes the serological groups D and Q: Streptococcus faecalis , S.faecalis subsp. liquifaciens, S.faecalis subsp. zymogenes, S.faecium...priority sampling point would normally be at the influent to a treatment plant. For small and medium sized wastewater systems, sampling at the first...theoretical settling rate of a spherical solid in a quiescent aqueous medium is given by Stokes’ Law: V D2 (Ss- Sw)gS = 18 v Where: Vs = settling velocity D

  2. bacteriological quality of water samples in

    African Journals Online (AJOL)

    met by water obtained from rainfall, streams, means of preventing pollution of the water well, boreholes or tap depending on the ... Most organized consumption of bottled and sachet water in a society depends on piped treated water to ... bottles containing 3% sodium thiosulphate solution (6). The pH and suspended solid.

  3. Use of skin stretchers for single-stage bilateral mastectomies in a dog and a cat.

    Science.gov (United States)

    Miyazaki, Yuta; Aikawa, Takeshi; Shimatsu, Taichi; Nishimura, Masaaki; Sadahiro, Shigeo

    2018-04-01

    To describe the application of skin stretchers for closure of single-stage bilateral mastectomies in a dog and a cat. Clinical case report. A 12-year-old intact female Miniature Dachshund and a 13-year-old spayed female domestic short-hair cat. Skin stretchers were applied to the site of the skin adjacent to mammary glands for 2-4 days before surgery. Cable tension was adjusted every 6-8 hours to elongate the skin and to achieve primary closure of single-stage bilateral mastectomy without tension. Wound closure after single-stage bilateral mastectomy was achieved without tension or major complication in both animals. Use of skin stretchers allows primary closure of single-stage bilateral mastectomy in dogs and cats. © 2017 The American College of Veterinary Surgeons.

  4. Single-Stage, Gelled Hydrazine System for Mars Ascent Vehicle Propulsion, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcosm, Inc. in cooperation with Aerojet Rocketdyne is presenting an innovative approach to the Mars Ascent Vehicle (MAV). The single-stage monopropellant system...

  5. Single Stage Transthoracic Approach to the Right Lung and Liver Dome Hydatid Cysts

    Directory of Open Access Journals (Sweden)

    Rasih Yazkan

    2011-09-01

    lung, the hepatic lesions were all of the dome located. Conclusions :Single stage transthoracic approach is prevent the second surgical procedures on simultaneous right lung and liver dome hydatid cyst and it is safe and effective method.

  6. NOFBX Single-Stage-to-Orbit Mars Ascent Vehicle Engine, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the continuation of our research and development of a Nitrous Oxide Fuel Blend (NOFBXTM) Single-Stage-to-Orbit (SSTO) monopropellant propulsion system for...

  7. Single Stage Knee Arthroplasty Revision Surgery: A Systematic Review of the Literature.

    Science.gov (United States)

    Chew, E; Khan, W S; Agarwal, S; Morgan-Jones, R

    2015-01-01

    Total Knee Arthroplasty is an increasingly common procedure and revision surgery, particularly for infection, is associated with significant morbidity and healthcare costs. The current gold standard is a two stage revision procedure but single stage revision is increasingly being used in some departments to improve patient outcomes. We conducted a systematic review of the literature to determine the up-to-date evidence underlying the use of a single stage knee approach in revision surgery. A total of 12 studies were included in this review amounting to 433 revision surgeries. This is the largest review of single stage knee revision surgery. The procedures described were heterogenous and included the 'two-in-one' technique as well as other single stage revision procedures. There were also differences in implants and antibiotic regimens. The mean re-infection rates described in 10 studies was 9.4% (range 0-19.2%) after a mean follow-up of 40.3 months (range 7-180 months). The re-infection rates in the studies published over the last 30 years are falling, and this is not accounted for by any significant change in duration of follow-up during this period. The outcome scores varied, but patients generally showed an improvement. The Knee Society Score and the Oxford Knee Score were the most commonly used in five and three studies respectively. We conclude that the current evidence for single stage revision is variable and there is a lack of good quality evidence to address whether single stage revisions is thorough enough to eradicate deep infection and is able to restore adequate function. There is a need for larger prospective studies with standardised procedures and protocol, and with adequate follow-up. Till then, patients considered for a single stage approach should be thoroughly assessed and the surgery should be performed by a senior surgeon with experience in single stage knee revisions.

  8. Single-stage revision for periprosthetic hip infection using antibiotic loaded impaction graft.

    Science.gov (United States)

    Ebied, Ayman M; Elseedy, Adel I; Gamal, Osama

    2016-11-10

    Staged revision for periprosthetic infection of the hip is an accepted and widely used technique by many surgeons. However, single-stage exchange of the hip prosthesis remains an attractive option to others because of the advantages of reduced morbidity, shorter treatment time and hospital stay in addition to the reduced cost of treatment. Single-stage revision for periprosthetic hip infection can achieve excellent results if a specific protocol for patients' selection and management is followed. 52 patients with evidence of periprosthetic infection had preoperative aspiration of the affected hip. The infecting organisms were identified in 33/52 and single-stage revision was performed. The remaining 19 patients had a 2-stage exchange arthroplasty. Patients in the single-stage revision protocol had antibiotic loaded morsellized bone graft, a cemented cup and a long cementless stem. At an average follow up of 6 (range 4-8) years postoperatively, only 1 case of persistent infection was found in the single-stage group - a 97% rate of eradicating infection was achieved. Single-stage exchange achieves excellent success rate in patients with periprosthetic infection when a specific protocol for patient selection and management is followed.

  9. Thermodynamic simulation of condensation heat recovery characteristics of a single stage centrifugal chiller in a hotel

    International Nuclear Information System (INIS)

    Gong, Guangcai; Chen, Feihu; Su, Huan; Zhou, Jianyong

    2012-01-01

    Highlights: ► Thermodynamic model of a two-condenser condensation system has been carried out. ► Dynamic simulation method has been presented. ► COP and g of the refrigerating system is better than the single condensation system. ► The optimal parameters for the two-condenser condensation system have been studied. -- Abstract: A thermodynamic simulation study has been carried out for a single stage centrifugal chiller in this paper. The cooling capacity of the chiller unit is about 1750 kW. The chiller unit has been set and tested, and the work refrigerant is R22. A heat exchanger has been set between outlet of the compressor and the condenser for sanitary hot water supplying. Then the chiller unit is a kind of combined system that can provide sanitary hot water supplying and air conditioning simultaneously. A thermodynamic simulation model of the combined system has been established with the system simulation toolbox Simulink. Performance of the components and the combined system of the chiller unit has been studied over a wide range of operating conditions. The potential energy and fuel cost saving associated with the use of the proposed combined system for a typical hotel in south China has been estimated. It is showed that the combined system of the chiller unit is very useful in hotel buildings. And the thermodynamic simulation model of the combined system is significance for the optimization of parameters of the chiller unit such as condensation and evaporation temperature, mass flow of the sanitary hot water and size of hot water storage tank.

  10. Bacteriological quality of water samples in Osogbo Metropolis ...

    African Journals Online (AJOL)

    The bacteriological qualities of samples of some sachet water, tap water and well water were examined. Some physicochemical parameters (pH and suspended solids) indicative of water quality as well as the total bacterial and total coliform counts were examined. The pH of the samples range between 6.5 and 7.2.

  11. UMTRA water sampling and analysis plan, Green River, Utah

    International Nuclear Information System (INIS)

    Papusch, R.

    1993-12-01

    The purpose of this water sampling and analysis plan (WSAP) is to provide a basis for groundwater and surface water sampling at the Green River Uranium Mill Tailing Remedial Action (UMTRA) Project site. This WSAP identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the monitoring locations

  12. Single-Stage Revision Arthroplasty for Infection-An Underutilized Treatment Strategy.

    Science.gov (United States)

    Negus, Jonathan J; Gifford, Peter B; Haddad, Fares S

    2017-07-01

    The burden of revision arthroplasty surgery for infection is rising as the rate of primary arthroplasty surgery increases. Infected arthroplasty rates are now relatively low, but the sheer increase in volume is leading to considerable patient morbidity and significant increases in costs to the health care system. Single-stage revision for infection is one of the several accepted treatment options, but the indications and results are debated. This review aims to clarify the current evidence. MEDLINE/PubMed databases were reviewed for studies that looked at single- or one-stage revision knee or hip arthroplasty for infection. There is increasing evidence that single-stage revision for infection can control infection and with decreased morbidity, mortality, and health care costs compared with a staged approach. However, the indications are still debated. Recently, there has been a determined effort to define an infected arthroplasty in a manner that will allow for standardization of reporting in the literature. The evidence supporting single stage for knee arthroplasty is catching up with the result with hip arthroplasty. High-quality data from randomized controlled trials are now pending. After the gradual evolution of using the single-stage approach, with the widespread acceptance of this definition, we can now standardize comparisons across the world and move toward a refined definition of the ideal patient population for single-stage arthroplasty revision in both the hip and the knee population. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Characterization of indicator bacteria in municipal raw water, drinking water, and new main water samples.

    Science.gov (United States)

    Clark, J A; Burger, C A; Sabatinos, L E

    1982-09-01

    Municipal water samples were analyzed by membrane filter (MF) and presence-absence (P-A) tests for pollution indicator bacteria. In four years, 11 514 bacterial cultures were isolated from either raw water, drinking water, or new main water samples submitted to three environmental laboratories. The bacterial species occurring most often in all types of water samples were Escherichia coli (11.6-39.7%), Enterobacter aerogenes (18.1-26.3%), Aeromonas hydrophila (8.8-17.0%), Klebsiella pneumoniae (7.7-10.3%), and Citrobacter freundii (5.9-22.7%). A lactose - lauryl tryptose - tryptone broth was examined as an alternative medium to modified MacConkey broth in the presumptive portion of the P-A test. The intensity of acid and gas production in presumptive positive P-A bottles was compared with the types and frequencies of indicator bacteria shown by confirmatory tests. The results of detecting indicator bacteria following the analysis of 53 130 samples over a 2-year period were arranged by water source (well, lake, river, mixed) and water type (raw or drinking) to determine the influence of these parameters on the recovery of indicator bacteria. A further subdivision of the sample types into raw surface, raw ground, in-plant, plant discharge, reservoir, and distribution samples demonstrated the effect of water treatment practices.

  14. Par Pond refill water quality sampling

    Energy Technology Data Exchange (ETDEWEB)

    Koch, J.W. II; Martin, F.D.; Westbury, H.M.

    1996-08-01

    This study was designed to document anoxia and its cause in the event that the anoxia caused a fish kill. However, no fish kill was observed during this study, and dissolved oxygen and nutrient concentrations generally remained within the range expected for southeastern reservoirs. Par Pond water quality monitoring will continue during the second summer after refill as the aquatic macrophytes become reestablished and nutrients in the sediments are released to the water column.

  15. chemical and microbiological assessment of surface water samples ...

    African Journals Online (AJOL)

    PROF EKWUEME

    The importance of good quality water cannot be over emphasized. This is because it is only next to air as a critical sustainer of life therefore it is appropriate to evaluate its quality and quantity. A total number of thirteen water samples were investigated in this study: Nine samples from different surface water bodies, two ...

  16. Chemical and microbiological assessment of surface water samples ...

    African Journals Online (AJOL)

    The importance of good quality water cannot be over emphasized. This is because it is only next to air as a critical sustainer of life therefore it is appropriate to evaluate its quality and quantity. A total number of thirteen water samples were investigated in this study: Nine samples from different surface water bodies, two ...

  17. UMTRA project water sampling and analysis plan, Gunnison, Colorado

    International Nuclear Information System (INIS)

    1994-06-01

    This water sampling and analysis plan summarizes the results of previous water sampling activities and the plan for water sampling activities for calendar year 1994. A buffer zone monitoring plan is included as an appendix. The buffer zone monitoring plan is designed to protect the public from residual contamination that entered the ground water as a result of former milling operations. Surface remedial action at the Gunnison Uranium Mill Tailings Remedial Action Project site began in 1992; completion is expected in 1995. Ground water and surface water will be sampled semiannually in 1994 at the Gunnison processing site (GUN-01) and disposal site (GUN-08). Results of previous water sampling at the Gunnison processing site indicate that ground water in the alluvium is contaminated by the former uranium processing activities. Background ground water conditions have been established in the uppermost aquifer (Tertiary gravels) at the Gunnison disposal site. The monitor well locations provide a representative distribution of sampling points to characterize ground water quality and ground water flow conditions in the vicinity of the sites. The list of analytes has been modified with time to reflect constituents that are related to uranium processing activities and the parameters needed for geochemical evaluation. Water sampling will be conducted at least semiannually during and one year following the period of construction activities, to comply with the ground water protection strategy discussed in the remedial action plan (DOE, 1992a)

  18. Numerical Simulation of single-stage axial fan operation under dusty flow conditions

    Science.gov (United States)

    Minkov, L. L.; Pikushchak, E. V.

    2017-11-01

    Assessment of the aerodynamic efficiency of the single-stage axial flow fan under dusty flow conditions based on a numerical simulation using the computational package Ansys-Fluent is proposed. The influence of dust volume fraction on the dependences of the air volume flow rate and the pressure drop on the rotational speed of rotor is demonstrated. Matching functions for formulas describing a pressure drop and volume flow rate in dependence on the rotor speed and dust content are obtained by numerical simulation for the single-stage axial fan. It is shown that the aerodynamic efficiency of the single-stage axial flow fan decreases exponentially with increasing volume content of dust in the air.

  19. Analysis of phthalate esters contamination in drinking water samples ...

    African Journals Online (AJOL)

    The optimum condition method was successfully applied to the analysis of phthalate esters contamination in bottled drinking water samples. The concentration of DMP, DEP and DBP in drinking water samples were below allowable levels, while the DEHP concentration in three samples was found to be greater than the ...

  20. Guidelines for sampling fish in inland waters

    National Research Council Canada - National Science Library

    Backiel, Tadeusz; Welcomme, R. L

    1980-01-01

    The book is addressed mainly to Fishery Biologists but it is hoped that Fishing Gear Technologists also can acquire some basic knowledge of sampling problems and procedures which, in turn, can result...

  1. Catch me if you can: Comparing ballast water sampling skids to traditional net sampling

    Science.gov (United States)

    Bradie, Johanna; Gianoli, Claudio; Linley, Robert Dallas; Schillak, Lothar; Schneider, Gerd; Stehouwer, Peter; Bailey, Sarah

    2018-03-01

    With the recent ratification of the International Convention for the Control and Management of Ships' Ballast Water and Sediments, 2004, it will soon be necessary to assess ships for compliance with ballast water discharge standards. Sampling skids that allow the efficient collection of ballast water samples in a compact space have been developed for this purpose. We ran 22 trials on board the RV Meteor from June 4-15, 2015 to evaluate the performance of three ballast water sampling devices (traditional plankton net, Triton sampling skid, SGS sampling skid) for three organism size classes: ≥ 50 μm, ≥ 10 μm to performance.

  2. Spectrophotometric Determination of Boron in Environmental Water Samples

    International Nuclear Information System (INIS)

    San San; Khin Win Kyi; Kwaw Naing

    2002-02-01

    The present paper deals with the study on the methods for the determination of boron in the environmental water samples. The standard methods which are useful for this determination are discussed thoroughly in this work. Among the standard methods approved by American Public Health Association, the carmine method was selected for this study. Prior to the determination of boron in the water samples, the precision and accuracy of the methods of choice were examined by using standard boron solutions. The determination of Boron was carried out by using water samples, waste water from Aquaculture Research Centre, University of Yangon, the Ayeyarwady River water near Magway Myathalon Pagoda in Magway Division, ground water from Sanchaung Township, and tap water from Universities' Research Centre, University of Yangon. Analyses of these water samples were done and statistical treatment of the results was carried out. (author)

  3. Design considerations for single-stage and two-stage pneumatic pellet injectors

    International Nuclear Information System (INIS)

    Gouge, M.J.; Combs, S.K.; Fisher, P.W.; Milora, S.L.

    1988-09-01

    Performance of single-stage pneumatic pellet injectors is compared with several models for one-dimensional, compressible fluid flow. Agreement is quite good for models that reflect actual breech chamber geometry and incorporate nonideal effects such as gas friction. Several methods of improving the performance of single-stage pneumatic pellet injectors in the near term are outlined. The design and performance of two-stage pneumatic pellet injectors are discussed, and initial data from the two-stage pneumatic pellet injector test facility at Oak Ridge National Laboratory are presented. Finally, a concept for a repeating two-stage pneumatic pellet injector is described. 27 refs., 8 figs., 3 tabs

  4. imulation Results of Single Stage AC- AC Converter for Induction Heating

    Directory of Open Access Journals (Sweden)

    S. ARUMUGAM

    2010-12-01

    Full Text Available This paper presents simulation of single stage Induction heating system with series Load Resonance. Low frequency AC is converted in to High Frequency Ac using newly developed ZVS-PWM high frequency inverter. This High Frequency is used for Induction Heating .Single stage AC-AC converter system is modeled and simulated using Matlab Simulink. The simulation results of ZVS-PWM high frequency system are presented. The effectiveness of this UFAC-to-HFAC direct power frequency converter using IGBTs for consumer high-frequency IH appliances is evaluated and proved on the basis of simulation results.

  5. Preconcentration NAA for simultaneous multielemental determination in water sample

    International Nuclear Information System (INIS)

    Chatt, A.

    1999-01-01

    Full text: Environment concerns with water, air, land and their interrelationship viz., human beings, fauna and flora. One of the important environmental compartments is water. Elements present in water might face a whole lot of physico-chemical conditions. This poses challenges to measure their total concentrations as well as different species. Preconcentration of the elements present in water samples is a necessary requisites in water analysis. For multi elements concentration measurements, Neutron Activation Analysis (NAA) is one of the preferred analytical techniques due to its sensitivity and selectivity. In this talk preconcentration NAA for multielemental determination in water sample determination will be discussed

  6. Measurement of radioactivity in water samples

    International Nuclear Information System (INIS)

    Richards, L.

    1990-01-01

    Public concern about the levels of radioactivity release to the environment whether authorised discharges or resulting from nuclear accident, has increased in recent years. Consequently there is increasing pressure for reliable data on the distribution of radioactivity and the extent of its intrusion into food chains and water supplies. As a result a number of laboratories not experienced in radioactivity measurements have acquired nucleonic counting equipment. These notes explore the underlying basics and indicate sources of essential data and information which are required for a better understanding of radioactivity measurements. Particular attention is directed to the screening tests which are usually designated ''gross'' alpha and ''gross'' beta activity measurement. (author)

  7. UMTRA project water sampling and analysis plan, Naturita, Colorado

    International Nuclear Information System (INIS)

    1994-04-01

    Surface remedial action is scheduled to begin at the Naturita UMTRA Project processing site in the spring of 1994. No water sampling was performed during 1993 at either the Naturita processing site (NAT-01) or the Dry Flats disposal site (NAT-12). Results of previous water sampling at the Naturita processing site indicate that ground water in the alluvium is contaminated as a result of uranium processing activities. Baseline ground water conditions have been established in the uppermost aquifer at the Dry Flats disposal site. Water sampling activities scheduled for April 1994 include preconstruction sampling of selected monitor wells at the processing site, surface water sampling of the San Miguel River, sampling of several springs/seeps in the vicinity of the disposal site, and sampling of two monitor wells in Coke Oven Valley. The monitor well locations provide sampling points to characterize ground water quality and flow conditions in the vicinity of the sites. The list of analytes has been updated to reflect constituents related to uranium processing activities and the parameters needed for geochemical evaluation. Water sampling will be conducted annually at minimum during the period of construction activities

  8. Practical Considerations Concerning the Interleaved Transition Mode Single-stage Ballast

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Kjær, Søren Bækhøj; Munk-Nielsen, Stig

    2002-01-01

    The aim of this paper is to present a novel single-stage interleaved ballast focusing on practical design aspects like: key current expression, overall losses, harmonic analysis of the differential-mode EMI current and preheating ballast function. A new preheating method is also presented. A PSPI...

  9. Single-Stage Low-Power Quadrature RF Receiver Front-End: The LMV Cell

    DEFF Research Database (Denmark)

    Liscidini, Antonio; Mazzanti, Andrea; Tonietto, Riccardo

    2006-01-01

    This paper presents the first quadrature RF receiver front-end where, in a single stage, low-noise amplifier (LNA), mixer and voltage-controlled oscillator (VCO) share the same bias current. The new structure exploits the intrinsic mixing functionality of a classical LC-tank oscillator providing ...

  10. Single stage buck-boost DC-AC neutral point clamped inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Andrew, A.

    2012-01-01

    This paper proposes a new single stage buck-boost DC-AC neutral point clamped inverter topology which integrates the cascaded configurations of recently introduced inductor-capacitor-capacitor-transformer impedance source network (by Adamowicz) and classic NPC configuration. As a consequence...

  11. Comparison between a two-stage and single-stage digesters when ...

    African Journals Online (AJOL)

    Phenol is a pollutant found in many industrial wastewaters, which diminishes biogas formation in anaerobic digesters. In this study, a two-stage (acidogenic and methanogenic) anaerobic digester (TSAD) was compared to a single stage digester (SSD), in treating a synthetic wastewater contaminated with phenol.

  12. Outcomes of single-stage grip-release reconstruction in tetraplegia.

    Science.gov (United States)

    Reinholdt, Carina; Fridén, Jan

    2013-06-01

    To evaluate the outcomes of our technique for single-stage grip-release reconstruction and compare it with previous 1- and 2-stage grip reconstructions in tetraplegia. A total of 14 patients (16 hands) with tetraplegia underwent a single-stage combination of operations to provide pinch, grip, and release function. We compared the study group with a historical control group of 15 patients (18 hands) who had been treated with staged flexion-extension grip-release reconstructions. Both groups were classified as ocular cutaneous 4. Assessment parameters included grip and pinch strength, maximal opening of the first webspace, and Canadian Occupational Performance Measurement. Both groups were rehabilitated with early active mobilization beginning the first day after surgery. Grip strength and opening of the first webspace were significantly greater in the single-stage group than in the comparative group. Pinch strength was not significantly different between groups. On the Canadian Occupational Performance Measurement score, patients belonging to the single-stage group were highly satisfied (increase of 3.7 points) and could perform several of their self-selected goals (3.5 points of improvement). The single-stage grip-release reconstruction provides people who have spinal cord injuries and tetraplegia with improved and reliable grip function; active finger flexion, active thumb flexion, passive thumb extension, and passive interossei function can all be achieved through this procedure. Early active mobilization is particularly important in improving functional outcome after this combination of grip reconstruction procedures. Therapeutic III. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  13. Determination of Phenols in Water Samples using a Supported ...

    African Journals Online (AJOL)

    The sample preparation method was tested for the determination of phenols in river water samples and landfill leachate. Concentrations of phenols in river water were found to be in the range 4.2 μg L–1 for 2-chlorophenol to 50 μg L–1 for 4-chlorophenol. In landfill leachate, 4-chlorophenol was detected at a concentration ...

  14. Radioactivity in waste water samples from COGEMA supplied by Greenpeace

    International Nuclear Information System (INIS)

    Reinen, H.A.J.M.; Kwakman, P.J.M.; Overwater, R.M.W.; Tax, R.B.; Nissan, L.A.

    1999-01-01

    The environmental organization Greenpeace sampled waste water from the reprocessing plant COGEMA in La Hague, France, in May 1999. On request of the Inspection Environmental Hygiene, The Dutch National Institute for Public Health and Environmental Protection (RIVM) determined the radioactivity of the waste water samples. 5 refs

  15. Measurement of 90Sr in fresh water samples

    International Nuclear Information System (INIS)

    Belanova, A.; Meresova, J.; Svetlik, I.; Tomaskova, L.

    2008-01-01

    This preliminary study show new experimental approach to the determination of the radionuclide 90 Sr in water samples. The new method of dynamic windows utilizing liquid scintillation counting was applied on model and surface water samples. Our results show the demand of separation technique with significantly higher yields. (authors)

  16. Sampling procedure for lake or stream surface water chemistry

    Science.gov (United States)

    Robert Musselman

    2012-01-01

    Surface waters collected in the field for chemical analyses are easily contaminated. This research note presents a step-by-step detailed description of how to avoid sample contamination when field collecting, processing, and transporting surface water samples for laboratory analysis.

  17. UMTRA project water sampling and analysis plan, Grand Junction, Colorado

    International Nuclear Information System (INIS)

    1994-07-01

    Surface remedial action will be completed at the Grand Junction processing site during the summer of 1994. Results of 1993 water sampling indicate that ground water flow conditions and ground water quality at the processing site have remained relatively constant with time. Uranium concentrations in ground water continue to exceed the maximum concentration limits, providing the best indication of the extent of contaminated ground water. Evaluation of surface water quality of the Colorado River indicate no impact from uranium processing activities. No compliance monitoring at the Cheney disposal site has been proposed because ground water in the Dakota Sandstone (uppermost aquifer) is classified as limited-use (Class 111) and because the disposal cell is hydrogeologically isolated from the uppermost aquifer. The following water sampling and water level monitoring activities are planned for calendar year 1994: (i) Semiannual (early summer and late fall) sampling of six existing monitor wells at the former Grand Junction processing site. Analytical results from this sampling will be used to continue characterizing hydrogeochemical trends in background ground water quality and in the contaminated ground water area resulting from source term (tailings) removal. (ii) Water level monitoring of approximately three proposed monitor wells projected to be installed in the alluvium at the processing site in September 1994. Data loggers will be installed in these wells, and water levels will be electronically monitored six times a day. These long-term, continuous ground water level data will be collected to better understand the relationship between surface and ground water at the site. Water level and water quality data eventually will be used in future ground water modeling to establish boundary conditions in the vicinity of the Grand Junction processing site. Modeling results will be used to help demonstrate and document the potential remedial alternative of natural flushing

  18. Soil Gas Sample Handling: Evaluation of Water Removal and Sample Ganging

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, Brad G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Abrecht, David G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hayes, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mendoza, Donaldo P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-10-31

    Soil gas sampling is currently conducted in support of Nuclear Test Ban treaty verification. Soil gas samples are collected and analyzed for isotopes of interest. Some issues that can impact sampling and analysis of these samples are excess moisture and sample processing time. Here we discuss three potential improvements to the current sampling protocol; a desiccant for water removal, use of molecular sieve to remove CO2 from the sample during collection, and a ganging manifold to allow composite analysis of multiple samples.

  19. UMTRA project water sampling and analysis plan, Tuba City, Arizona

    International Nuclear Information System (INIS)

    1996-02-01

    Planned, routine ground water sampling activities at the U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site in Tuba City, Arizona, are described in the following sections of this water sampling and analysis plan (WSAP). This plan identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the stations routinely monitored at the site. The ground water data are used for site characterization and risk assessment. The regulatory basis for routine ground water monitoring at UMTRA Project sites is derived from the U.S. Environmental Protection Agency (EPA) regulations in 40 CFR Part 192 (1994) and the final EPA standards of 1995 (60 FR 2854). Sampling procedures are guided by the UMTRA Project standard operating procedures (SOP) (JEG, n.d.), and the most effective technical approach for the site

  20. Grid Integration of Single Stage Solar PV System using Three-level Voltage Source Converter

    Science.gov (United States)

    Hussain, Ikhlaq; Kandpal, Maulik; Singh, Bhim

    2016-08-01

    This paper presents a single stage solar PV (photovoltaic) grid integrated power generating system using a three level voltage source converter (VSC) operating at low switching frequency of 900 Hz with robust synchronizing phase locked loop (RS-PLL) based control algorithm. To track the maximum power from solar PV array, an incremental conductance algorithm is used and this maximum power is fed to the grid via three-level VSC. The use of single stage system with three level VSC offers the advantage of low switching losses and the operation at high voltages and high power which results in enhancement of power quality in the proposed system. Simulated results validate the design and control algorithm under steady state and dynamic conditions.

  1. Single-stage osseointegrated implants for nasal prosthodontic rehabilitation: A clinical report.

    Science.gov (United States)

    de Carvalho, Bruna M D F; Freitas-Pontes, Karina M; de Negreiros, Wagner A; Verde, Marcus A R L

    2015-08-01

    Malignant tumors in the nasal region may be treated by means of invasive surgical procedures, with large facial losses. Nasal prostheses, retained by osseointegrated facial implants, instead of plastic surgery, will, in most patients, offer good biomechanical and cosmetic results. This clinical report describes the prosthetic rehabilitation of a patient with nasal cancer who had the entire nasal vestibule removed in a single-stage surgical procedure in order to shorten the rehabilitation time. The nasal prosthesis was built on a 3-magnet bar and was made of platinum silicone with intrinsic pigmentation, thereby restoring the patient's appearance and self-esteem. The authors concluded that single-stage implants may reduce the rehabilitation time to as little as 1 month, and the correct use of materials and techniques may significantly improve the nasal prosthesis. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  2. Single-stage Modified Duhamel procedure for Hirschsprung′s disease : Our experience

    Directory of Open Access Journals (Sweden)

    Paras R Kothari

    2012-01-01

    Full Text Available Introduction: Primary single-stage pull-through for Hirschsprung′s disease (HD has been reported to give comparable surgical outcomes to staged operations with less morbidity. Herein, we present our experience with single-stage Modified Duhamel procedure for management of HD. Patients and Methods: This was a review of 48 cases of HD who underwent single-stage Modified Duhamel procedure without a protective colostomy. Results: The age at surgery ranged from 6 months to 10 years (median - 9 months, mean - 2.3 years. The average weight of the child was 7.2 kg (range, 4.9-22 kg. 38 (79.2% patients had classical rectosigmoid HD, the rest being long segment HD (the proximal most level being the splenic flexure. The average duration of surgery was 175 minutes (range, 130-245 minutes. The average blood loss was 45 ml. The average hospital stay was 7.2 days (range: 6-10 days. The major postoperative complications (n=3 included postoperative adhesive intestinal obstruction, anastomotic leak and persistent constipation due to residual aganglionosis. Each required a re-exploration. Minor complications included surgical site infection (n=3 and post-operative enterocolitis (n=3, which were managed conservatively. Six patients had constipation for a limited period post-operatively. All patients have a satisfactory functional outcome and normal development and growth. Conclusions: For HD, we recommend that single-stage Modified Duhamel procedure should be the preferred approach in view of its low morbidity, satisfactory functional outcome and avoidance of stoma, multiple surgeries and economic benefit in view of decreased hospital stay.

  3. Advanteges of using Two-Switch Forward in Single-Stage Power Factor Corrected Power Supplies

    DEFF Research Database (Denmark)

    Petersen, Lars

    2000-01-01

    A single-Stage power factor corrected power supply using a two-switch forward is proposed to increase efficiency. The converter is operated in the DCM (Discontinues Conduction Mode). This will insure the intermediate DC-bus to be controlled only by means of circuit parameters and therefore...... power supply has been implemented. The measured efficiency and power factor are about 87% and 0.96 respectively....

  4. The first preliminary experiments on an 84 GHz gyrotron with a single-stage depressed collector

    International Nuclear Information System (INIS)

    Shimozuma, T.; Sato, M.; Takita, Y.

    1997-10-01

    We fabricated and tested an 84GHz gyrotron with a single-stage depressed collector. The gyrotron has a high-voltage insulating section made of a low loss silicon nitride composite. In this preliminary experiment in the depressed collector configuration, we obtained 591kW, 41% operation with a depression voltage of 22.5kV. Access to the higher efficiency region was inhibited by an increase in anode current. (author)

  5. System and method for single-phase, single-stage grid-interactive inverter

    Science.gov (United States)

    Liu, Liming; Li, Hui

    2015-09-01

    The present invention provides for the integration of distributed renewable energy sources/storages utilizing a cascaded DC-AC inverter, thereby eliminating the need for a DC-DC converter. The ability to segment the energy sources and energy storages improves the maintenance capability and system reliability of the distributed generation system, as well as achieve wide range reactive power compensation. In the absence of a DC-DC converter, single stage energy conversion can be achieved to enhance energy conversion efficiency.

  6. Adaptive kanban control mechanism for a single-stage hybrid system

    Science.gov (United States)

    Korugan, Aybek; Gupta, Surendra M.

    2002-02-01

    In this paper, we consider a hybrid manufacturing system with two discrete production lines. Here the output of either production line can satisfy the demand for the same type of product without any penalties. The interarrival times for demand occurrences and service completions are exponentially distributed i.i.d. variables. In order to control this type of manufacturing system we suggest a single stage pull type control mechanism with adaptive kanbans and state independent routing of the production information.

  7. Single-stage reconstruction of flexor tendons with vascularized tendon transfers.

    Science.gov (United States)

    Cavadas, P C; Pérez-García, A; Thione, A; Lorca-García, C

    2015-03-01

    The reconstruction of finger flexor tendons with vascularized flexor digitorum superficialis (FDS) tendon grafts (flaps) based on the ulnar vessels as a single stage is not a popular technique. We reviewed 40 flexor tendon reconstructions (four flexor pollicis longus and 36 finger flexors) with vascularized FDS tendon grafts in 38 consecutive patients. The donor tendons were transferred based on the ulnar vessels as a single-stage procedure (37 pedicled flaps, three free flaps). Four patients required composite tendon and skin island transfer. Minimum follow-up was 12 months, and functional results were evaluated using a total active range of motion score. Multiple linear regression analysis was performed to evaluate the factors that could be associated with the postoperative total active range of motion. The average postoperative total active range of motion (excluding the thumbs) was 178.05° (SD 50°). The total active range of motion was significantly lower for patients who were reconstructed with free flaps and for those who required composite tendon and skin island flap. Age, right or left hand, donor/motor tendon and pulley reconstruction had no linear effect on total active range of motion. Overall results were comparable with a published series on staged tendon grafting but with a lower complication rate. Vascularized pedicled tendon grafts/flaps are useful in the reconstruction of defects of finger flexor tendons in a single stage, although its role in the reconstructive armamentarium remains to be clearly established. © The Author(s) 2014.

  8. Is Single-stage Revision Safe Following Infected Total Knee Arthroplasty? A Critical Review.

    Science.gov (United States)

    Vaishya, Raju; Agarwal, Amit Kumar; Rawat, Sudheer K; Singh, Harsh; Vijay, Vipul

    2017-08-30

    With the improvement in outcomes and modern prosthesis design, total knee arthroplasty (TKA) has now become a commonly performed surgery. It is postulated that a total of 2-5% of the primary and revision TKA becomes infected every year, requiring a revision procedure which to date is the conventional two-stage revision. The diagnosis and treatment of these periprosthetic infections is a major and challenging task, as it requires precise identification of the pathogen, meticulous debridement, and postoperative rehabilitation. To date, there have been very few studies in existing literature comparing the outcomes of single-stage versus two-stage procedure in infected TKA. The aim of the review was to provide the clinicians an insight into the outcome of the single-stage procedure compared to two-stage procedures and to suggest ways to improve the results further. In the following critical review, a total of 669 cases that underwent either a single or two-stage revision for infected TKA were studied. The postoperative functional scores were comparable in most studies during the early postoperative period. Our data supports the use of a single-stage revision surgery in infected TKA as an alternative to a conventional two-stage procedure. However, larger prospective and multicentric trials are required to validate our findings.

  9. Performance characteristics of an excimer laser (XeCl) with single-stage magnetic pulse compression

    Science.gov (United States)

    Varshnay, N. K.; Singh, A.; Benerji, N. S.

    2017-02-01

    Performance characteristics of an excimer laser (XeCl) with single-stage magnetic pulse compression suitable for material processing applications are presented here. The laser incorporates in-built compact gas circulation and gas cooling to ensure fresh gas mixture between the electrodes for repetitive operation. A magnetically coupled tangential blower is used for gas circulation inside the laser chamber for repetitive operation. The exciter consists of C-C energy transfer circuit and thyratron is used as a high-voltage main switch with single-stage magnetic pulse compression (MPC) between thyratron and the laser electrodes. Low inductance of the laser head and uniform and intense pre-ionization are the main features of the electric circuit used in the laser. A 250 ns rise time voltage pulse was compressed to 100 ns duration with a single-stage magnetic pulse compressor using Ni-Zn ferrite cores. The laser can generate about 150 mJ at ˜100 Hz rep-rate reliably from a discharge volume of 100 cm 3. 2D spatial laser beam profile generated is presented here. The profile shows that the laser beam is completely filled with flat-top which is suitable for material processing applications. The SEM image of the microhole generated on copper target is presented here.

  10. New current control based MPPT technique for single stage grid connected PV systems

    International Nuclear Information System (INIS)

    Jain, Sachin; Agarwal, Vivek

    2007-01-01

    This paper presents a new maximum power point tracking algorithm based on current control for a single stage grid connected photovoltaic system. The main advantage of this algorithm comes from its ability to predict the approximate amplitude of the reference current waveform or power that can be derived from the PV array with the help of an intermediate variable β. A variable step size for the change in reference amplitude during initial tracking helps in fast tracking. It is observed that if the reference current amplitude is greater than the array capacity, the system gets unstable (i.e. moves into the positive slope region of the p-v characteristics of the array). The proposed algorithm prevents the PV system from entering the positive slope region of the p-v characteristics. It is also capable of restoring stability if the system goes unstable due to a sudden environmental change. The proposed algorithm has been tested on a new single stage grid connected PV configuration recently developed by the authors to feed sinusoidal current into the grid. The system is operated in a continuous conduction mode to realize advantages such as low device current stress, high efficiency and low EMI. A fast MPPT tracker with single stage inverter topology operating in CCM makes the overall system highly efficient. Specific cases of the system, operating in just discontinuous current mode and discontinuous current mode and their relative merits and demerits are also discussed

  11. UMTRA water sampling and analysis plan, Lakeview, Oregon

    International Nuclear Information System (INIS)

    1993-01-01

    The purpose of this document is to provide background, guidance, and justification for water sampling activities for the Lakeview, Oregon, Uranium Mill Tailings Remedial Action (UMTRA) processing and disposal sites. This water sampling and analysis plan will form the basis for groundwater sampling and analysis work orders (WSAWO) to be implemented during 1993. Monitoring at the former Lakeview processing site is for characterization purposes and in preparation for the risk assessment, scheduled for the fall of 1993. Compliance monitoring was conducted at the disposal site. Details of the sampling plan are discussed in Section 5.0

  12. Sampling and Analysis Plan for the 105-N Basin Water

    International Nuclear Information System (INIS)

    R.O. Mahood

    1997-01-01

    This sampling and analysis plan defines the strategy, and field and laboratory methods that will be used to characterize 105-N Basin water. The water will be shipped to the 200 Area Effluent Treatment Facility for treatment and disposal as part of N Reactor deactivation. These analyses are necessary to ensure that the water will meet the acceptance criteria of the ETF, as established in the Memorandum of Understanding for storage and treatment of water from N-Basin (Appendix A), and the characterization requirements for 100-N Area water provided in a letter from ETF personnel (Appendix B)

  13. Preconcentration of uranium in water samples using dispersive ...

    African Journals Online (AJOL)

    Preconcentration of uranium in water samples using dispersive liquid-liquid micro- extraction coupled with solid-phase extraction and determination with inductively coupled plasma-optical emission spectrometry.

  14. Two-stage IMZ implants and ITI implants inserted in a single-stage procedure. A prospective comparative study.

    Science.gov (United States)

    Heydenrijk, Kees; Raghoebar, Gerry M; Meijer, Henny J A; van der Reijden, Willy A; van Winkelhoff, Arie Jan; Stegenga, Boudewijn

    2002-08-01

    The aim of this study was to evaluate the feasibility of using a two-stage implant system in a single-stage procedure and to study the impact of the microgap at crestal level and to monitor the microflora in the peri-implant area. Forty edentulous patients (Cawood & Howell class V-VI) participated in this study. After randomisation, 20 patients received two IMZ implants inserted in a single-stage procedure and 20 patients received two ITI implants. After 3 months, overdentures were fabricated, supported by a bar and clip attachment. A standardised clinical and radiographic evaluation was performed immediately after denture insertion and 6 and 12 months later. Twelve months after loading, peri-implant samples were collected with sterile paper points and analysed for the presence of putative periodontal pathogens using culture techniques. One IMZ implant was lost due to insufficient osseointegration. With regard to the clinical parameters at the 12 months evaluation, significant differences for plaque score and probing pocket depth (IMZ: mean 3.3 mm, ITI: mean 2.9 mm) were found between the two groups. The mean bone loss in the first year of functioning was 0.6 mm for both groups. Prevotella intermedia was detected more often in the ITI group (12 implants) than in the IMZ group (three implants). Porphyromonas gingivalis was found in three patients. In one of these patients an implant showed bone loss of 1.6 mm between T0 and T12. Some associations were found between clinical parameters and the target microorganisms in the ITI group. These associations were not present in the IMZ group. The short-term results indicate that two-stage implants inserted in a single-stage procedure may be as predictable as one-stage implants. The microgap at crestal level in nonsubmerged IMZ implants seems to have no adverse influence on the peri-implant microbiological colonisation and of crestal bone loss in the first year of functioning. The peri-implant sulcus can and does harbour

  15. Bacterial contamination of water samples in Gabon, 2013

    Directory of Open Access Journals (Sweden)

    Jonas Ehrhardt

    2017-10-01

    Full Text Available Contamination of water is a major burden in the public health setting of developing countries. We therefore assessed the quality of water samples in Gabon in 2013. The main findings were a contamination rate with coliforms of 13.5% and the detection of a possible environmental reservoir for extended spectrum beta-lactamase-producing bacteria.

  16. determination of lead at nanogram level in water samples

    African Journals Online (AJOL)

    Preferred Customer

    As is well known, heavy metal pollution has been a focus of attention all over the world. Metal ions frequently contained in industrial and municipal wastewater can be harmful to aquatic ... an urgent need to develop a simple and sensitive conventional method for measuring lead ion in ..... 5 Drinking water, sea water sample.

  17. Contamination of Ground Water Samples from Well Installations

    DEFF Research Database (Denmark)

    Grøn, Christian; Madsen, Jørgen Øgaard; Simonsen, Y.

    1996-01-01

    Leaching of a plasticizer, N-butylbenzenesulfonamide, from ground water multilevel sampling installations in nylon has been demonstrated. The leaching resulted in concentrations of DOC and apparent AOX, both comparable with those observed in landfill contaminated ground waters. It is concluded...

  18. Contamination of Ground Water Samples from Well Installations

    DEFF Research Database (Denmark)

    Grøn, Christian; Madsen, Jørgen Øgaard; Simonsen, Y.

    1996-01-01

    Leaching of a plasticizer, N-butylbenzenesulfonamide, from ground water multilevel sampling installations in nylon has been demonstrated. The leaching resulted in concentrations of DOC and apparent AOX, both comparable with those observed in landfill contaminated ground waters. It is concluded...... that nylon should not be used in studies of contamination with organic compounds....

  19. Evaluation of ultrafiltration cartridges for a water sampling apparatus.

    Science.gov (United States)

    Holowecky, P M; James, R R; Lorch, D P; Straka, S E; Lindquist, H D A

    2009-03-01

    To determine the efficiency of various ultrafiltration cartridges (UFC) in concentrating test micro-organisms from drinking water. Replicate drinking water samples from three potable water supplies were dosed with Bacillus anthracis Sterne, Francisella tularensis LVS, Yersinia pestis CO92, bacteriophages MS2 and phi-X174, and Cryptosporidium parvum. The test micro-organisms were dosed together in 100 l of water, which was then recirculated through one of five different UFC until the retentate volume was reduced to c. 500 ml. The micro-organisms were assayed before and after ultrafiltration concentration and per cent recoveries were calculated. There were nine statistically significant differences among pairs of filters out of a possible 180 different combinations of UFC, test micro-organisms, and water types. No filter consistently performed better or worse than the others for each test micro-organism in all water samples tested. This study provides performance data on the ability of several different UFC to concentrate a panel of test micro-organisms from three sources of potable water. Water utilities and first responders may use these data when selecting UFC for use in emergency response protocols. This study also provides additional data as to the efficacy of ultrafiltration for recovering bacteria, virus-like particles, and protozoan oocysts from water samples.

  20. UMTRA project water sampling and analysis plan, Mexican Hat, Utah

    International Nuclear Information System (INIS)

    1994-04-01

    The Mexican Hat, Utah, Uranium Mill Tailings Remedial Action (UMTRA) Project site is a former uranium mill that is undergoing surface remediation in the form of on-site tailings stabilization. Contaminated surface materials from the Monument Valley, Arizona, UMTRA Project site have been transported to the Mexican Hat site and are being consolidated with the Mexican Hat tailings. The scheduled completion of the tailings disposal cell is August 1995. Water is found in two geologic units at the site: the Halgaito Shale Formation and the Honaker Trail Formation. The tailings rest on the Halgaito Shale, and water contained in that unit is a result of milling activities and, to a lesser extent, water released from the tailings from compaction during remedial action construction of the disposal cell. Water in the Halgaito Shale flows through fractures and discharges at seeps along nearby arroyos. Flow from the seeps will diminish as water drains from the unit. Ground water in the lower unit, the Honaker Trail Formation, is protected from contamination by an upward hydraulic gradient. There are no nearby water supply wells because of widespread poor background ground water quality and quantity, and the San Juan River shows no impacts from the site. This water sampling and analysis plan (WSAP) recommends sampling six seeps and one upgradient monitor well compared in the Honaker Trail Formation. Samples will be taken in April 1994 (representative of high group water levels) and September 1994 (representative of low ground water levels). Analyses will be performed on filtered samples for plume indicator parameters

  1. Microbial Bioload of Some Tap Water Samples from Enugu, Enugu ...

    African Journals Online (AJOL)

    Bacteriological screening on all sample groups indicated the presence of microorganism in tap water available in all eleven locations. Further characterization using biochemical methods revealed the absence of E. coli, and the presence of Pseudomonas aeruginosa. Shigella species and Salmonella species in sample ...

  2. GROUND WATER PURGING AND SAMPLING METHODS: HISTORY VS. HYSTERIA

    Science.gov (United States)

    It has been over 10 years since the low-flow ground water purging and sampling method was initially reported in the literature. The method grew from the recognition that well purging was necessary to collect representative samples, bailers could not achieve well purging, and high...

  3. Considerations of acidifying water samples for 99Tc analysis

    International Nuclear Information System (INIS)

    Blanchard, R.L.; Lieberman, R.; Richardson, W.S. III; Wakamo, C.L.

    1993-01-01

    Environmental water samples are routinely acidified before radionuclide analysis to prevent adsorption of radionuclides on the container walls. This study addresses the concern for volatilizing 99Tc from acid solutions during evaporation before beta analysis has been addressed. Water samples can be acidified to pH 1.7 with nitric acid and evaporated to dryness on planchets without significant losses of technetium due to volatilization. However, the planchets should not be flamed unless a detergent is used, and control samples should be flamed to determine the loss of activity under the conditions used

  4. Quality-control design for surface-water sampling in the National Water-Quality Network

    Science.gov (United States)

    Riskin, Melissa L.; Reutter, David C.; Martin, Jeffrey D.; Mueller, David K.

    2018-04-10

    The data-quality objectives for samples collected at surface-water sites in the National Water-Quality Network include estimating the extent to which contamination, matrix effects, and measurement variability affect interpretation of environmental conditions. Quality-control samples provide insight into how well the samples collected at surface-water sites represent the true environmental conditions. Quality-control samples used in this program include field blanks, replicates, and field matrix spikes. This report describes the design for collection of these quality-control samples and the data management needed to properly identify these samples in the U.S. Geological Survey’s national database.

  5. Minimally Invasive, Single-Stage, Multilevel Surgery for Obstructive Sleep Apnea in Asian Patients.

    Science.gov (United States)

    Lin, Hsin-Ching; Friedman, Michael; Chang, Hsueh-Wen; Bonzelaar, Lauren; Salapatas, Anna M; Lin, Meng-Chih; Huang, Kuo-Tung

    2017-02-01

    This study adds to the literature on the efficacy and low complication rates associated with minimally invasive, single-stage, multilevel surgery for Asian adults with obstructive sleep apnea (OSA) for whom conservative treatment had failed. Overall, our experience has produced results that make this procedure an option for select patients with snoring and OSA. To investigate the effectiveness and safety of anatomy-based, minimally invasive, single-stage, multilevel surgery in the treatment of OSA in an Asian population. This retrospective study enrolled 59 consecutive patients with OSA from a tertiary academic medical center who had multilevel obstruction and unsuccessful conservative therapy and then underwent minimally invasive, single-stage, multilevel surgery. The subjective symptoms and objective polysomnographic findings were collected preoperatively and at a minimum of 3 months postoperatively. The Global Patient Assessment questionnaire was used to assess patient satisfaction after minimally invasive, single-stage, multilevel surgery. Scores on the Epworth Sleepiness Scale and bed partner evaluation of patient's snoring on a visual analog scale (scale of 0-10, with 0 indicating no snoring and 10 indicating the bed partner to leave the room or sleep separately, as assessed by the bed partner). The primary outcomes are a 50% decrease in bed partner's snoring visual analog scale level postoperatively and an improvement of 50% or more in apnea-hypopnea index by an at least 3-month follow-up. Adverse events and patient-reported quality measures were also assessed. Forty-seven patients (36 men and 11 women; mean [SD], 47.3 [10.9] years) with a minimum 3-month follow-up and complete data were included in the analysis. None of the patients had serious perioperative or postoperative complications. Three months postoperatively, the mean (SD) scores on the Epworth Sleepiness Scale and bed partner evaluation of patient's snoring on the visual analog scale decreased

  6. Compositing water samples for analysis of volatile organic compounds

    Science.gov (United States)

    Lopes, T.J.; Fallon, J.D.; Maluk, T.L.

    2000-01-01

    Accurate mean concentrations of volatile organic compounds (VOCs) can easily and economically be obtained from a single VOC analysis by using proven methods of collecting representative, discrete water samples and compositing them with a gas-tight syringe. The technique can be used in conjunction with chemical analysis by a conventional laboratory, field-portable equipment, or a mobile laboratory. The type of mean concentration desired depends on the objectives of monitoring. For example, flow-weighted mean VOC concentrations can be used to estimate mass loadings in wastewater and urban storm water, and spatially integrated mean VOC concentrations can be used to assess sources of drinking water (e.g., reservoirs and rivers). The mean error in a discrete sample due to compositing is about 2% for most VOC concentrations greater than 0.1 ??g/L. The total error depends on the number of discrete samples comprising the composite sample and precision of the chemical analysis.Accurate mean concentrations of volatile organic compounds (VOCs) can easily and economically be obtained from a single VOC analysis by using proven methods of collecting representative, discrete water samples and compositing them with a gas-tight syringe. The technique can be used in conjunction with chemical analysis by a conventional laboratory, field-portable equipment, or a mobile laboratory. The type of mean concentration desired depends on the objectives of monitoring. For example, flow-weighted mean VOC concentrations can be used to estimate mass loadings in wastewater and urban storm water, and spatially integrated mean VOC concentrations can be used to assess sources of drinking water (e.g., reservoirs and rivers). The mean error in a discrete sample due to compositing is about 2% for most VOC concentrations greater than 0.1 ??g/L. The total error depends on the number of discrete samples comprising the composite sample and precision of the chemical analysis.Researchers are able to derive

  7. The collection and field chemical analysis of water samples

    International Nuclear Information System (INIS)

    Korte, N.E.; Ealey, D.T.; Hollenbach, M.H.

    1984-01-01

    A successful water sampling program requires a clear understanding of appropriate measurement and sampling procedures in order to obtain reliable field data and representative samples. It is imperative that the personnel involved have a thorough knowledge of the limitations of the techniques being used. Though this seems self-evident, many sampling and field-chemical-analysis programs are still not properly conducted. Recognizing these problems, the Department of Energy contracted with Bendix Field Engineering Corporation through the Technical Measurements Center to develop and select procedures for water sampling and field chemical analysis at waste sites. The fundamental causese of poor field programs are addressed in this paper, largely through discussion of specific field-measurement techniques and their limitations. Recommendations for improvement, including quality-assurance measures, are also presented

  8. Water Gas Shift Reaction with A Single Stage Low Temperature Membrane Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ciora, Richard J [Media and Process Technology Inc., Pittsburgh, PA (United States); Liu, Paul KT [Media and Process Technology Inc., Pittsburgh, PA (United States)

    2013-12-31

    Palladium membrane and Palladium membrane reactor were developed under this project for hydrogen separation and purification for fuel cell applications. A full-scale membrane reactor was designed, constructed and evaluated for the reformate produced from a commercial scale methanol reformer. In addition, the Pd membrane and module developed from this project was successfully evaluated in the field for hydrogen purification for commercial fuel cell applications.

  9. [Single-stage bilateral Pemberton's pericapsular osteotomy in bilateral developmental dysplasia of the hip].

    Science.gov (United States)

    Zorer, Gazi; Bagatur, A Erdem

    2002-01-01

    This study was designed to evaluate the results of single-stage bilateral Pemberton's pericapsular osteotomy with or without open reduction and to demonstrate its advantages over two separate consecutive interventions in bilateral developmental dysplasia of the hip (DDH). This prospective study included 20 patients (14 girls, 6 boys; mean age 30 months; range 12 to 60 months) with bilateral DDH, who underwent single-stage bilateral Pemberton's pericapsular osteotomy with (14 patients, group A1) or without (6 patients, group A2) open reduction. Twenty patients (16 girls, 4 boys; mean age 24 months; range 13 to 47 months) with unilateral DDH, who underwent Pemberton's pericapsular osteotomy with (12 patients, group B1) or without (8 patients, group B2) open reduction were enrolled into the study as controls. Single- and two-stage procedures were compared with regard to improvement in the acetabular index, complications, mean duration of anesthesia, perioperative need for blood transfusion, length of hospital stay, initiation of walking, overall cost of antibiotic prophylaxis, and total hospital charge. There were no significant differences between A1 and B1, A2 and B2 groups with respect to mean age, gender, pre- and postoperative acetabular indices, and recovery times. However, duration of anesthesia, length of hospital stay, cost of antibiotic prophylaxis, and total hospital charges differed significantly. The amount of blood transfusion differed significantly only between groups A1 and B1. The length of hospital stay and cost of antibiotic prophylaxis in group A2 was twice as much as that of group B2. Increases in other parameters ranged between 22% to 37%. No early or late complications were encountered. Single-stage bilateral Pemberton's pericapsular osteotomy in patients with bilateral DDH seems to have significant advantages over two separate consecutive interventions. However, increased risks of bilateral osteotomies require that sufficiently equipped and

  10. Single-stage electrohydraulic servosystem for actuating on airflow valve with frequencies to 500 hertz

    Science.gov (United States)

    Webb, J. A., Jr.; Mehmed, O.; Lorenzo, C. F.

    1980-01-01

    An airflow valve and its electrohydraulic actuation servosystem are described. The servosystem uses a high-power, single-stage servovalve to obtain a dynamic response beyond that of systems designed with conventional two-stage servovalves. The electrohydraulic servosystem is analyzed and the limitations imposed on system performance by such nonlinearities as signal saturations and power limitations are discussed. Descriptions of the mechanical design concepts and developmental considerations are included. Dynamic data, in the form of sweep-frequency test results, are presented and comparison with analytical results obtained with an analog computer model is made.

  11. The Lifetime Estimate for ACSR Single-Stage Splice Connector Operating at Higher Temperatures

    International Nuclear Information System (INIS)

    Wang, Jy-An John; Graziano, Joe; Chan, John

    2011-01-01

    This paper is the continuation of Part I effort to develop a protocol of integrating analytical and experimental approaches to evaluate the integrity of a full tension single-stage splice connector (SSC) assembly during service at high operating temperature.1The Part II efforts are mainly focused on the thermal mechanical testing, thermal-cycling simulation and its impact on the effective lifetime of the SSC system. The investigation indicates that thermal cycling temperature and frequency, conductor cable tension loading, and the compressive residual stress field within a SSC system have significant impact on the SSC integrity and the associated effective lifetime.

  12. 85,000-GPM, single-stage, single-suction LMFBR intermediate centrifugal pump

    International Nuclear Information System (INIS)

    Fair, C.E.; Cook, M.E.; Huber, K.A.; Rohde, R.

    1983-01-01

    The mechanical and hydraulic design features of the 85,000-gpm, single-stage, single-suction pump test article, which is designed to circulate liquid-sodium coolant in the intermediate heat-transport system of a Large-Scale Liquid Metal Fast Breeder Reactor (LS-LMFBR), are described. The design and analytical considerations used to satisfy the pump performance and operability requirements are presented. The validation of pump hydraulic performance using a hydraulic scale-model pump is discussed, as is the featute test for the mechanical-shaft seal system

  13. Fault Diagnosis for Engine Based on Single-Stage Extreme Learning Machine

    Directory of Open Access Journals (Sweden)

    Fei Gao

    2016-01-01

    Full Text Available Single-Stage Extreme Learning Machine (SS-ELM is presented to dispose of the mechanical fault diagnosis in this paper. Based on it, the traditional mapping type of extreme learning machine (ELM has been changed and the eigenvectors extracted from signal processing methods are directly regarded as outputs of the network’s hidden layer. Then the uncertainty that training data transformed from the input space to the ELM feature space with the ELM mapping and problem of the selection of the hidden nodes are avoided effectively. The experiment results of diesel engine fault diagnosis show good performance of the SS-ELM algorithm.

  14. Single-stage MPPT control realization for Aalborg inverter in photovoltaic system

    DEFF Research Database (Denmark)

    Zhang, Shuai; Wu, Weimin; Wang, Houqing

    2017-01-01

    In this paper, the single-stage Maximum Power Point Tracking (MPPT) control strategy for the Aalborg photovoltaic inverter is presented. Aalborg inverter has many advantages, such as high efficiency, wide range of input voltage, minimum voltage drop of the filtering inductors, etc. Nevertheless......, it is essentially a “half-bridge” inverter with two input sources, where one source works in MPPT mode, the other is out of control. If without the reasonable parameter design and the proper control, the bus-voltage of this inverter may change greatly, resulting in the serious power oscillation around maximum power...... that the proposed control strategy has good steady-state and dynamic performances....

  15. Promising results after single-stage reconstruction of the nipple and areola complex

    DEFF Research Database (Denmark)

    Børsen-Koch, Mikkel; Bille, Camilla; Thomsen, Jørn B

    2013-01-01

    a technique based on a local flap for reconstruction of the nipple in combination with immediate intradermal tattooing for reconstruction of the areola. Results: We reviewed the outcome of 22 cases of women who had simple single-stage reconstruction over a period of one year. We found no major and only two...... minor complications including one case of partial flap necrosis and one case of infection. Only three patients needed additional tattooing after a three-month period. The cosmetic outcome was satisfactory and none of the patients needed corrective procedures. The mean procedure time for unilateral...

  16. Performance of the rebuilt SUERC single-stage accelerator mass spectrometer

    Science.gov (United States)

    Shanks, Richard P.; Ascough, Philippa L.; Dougans, Andrew; Gallacher, Paul; Gulliver, Pauline; Rood, Dylan H.; Xu, Sheng; Freeman, Stewart P. H. T.

    2015-10-01

    The SUERC bipolar single-stage accelerator mass spectrometer (SSAMS) has been dismantled and rebuilt to accommodate an additional rotatable pre-accelerator electrostatic spherical analyser (ESA) and a second ion source injector. This is for the attachment of an experimental positive-ion electron cyclotron resonance (ECR) ion source in addition to a Cs-sputter source. The ESA significantly suppresses oxygen interference to radiocarbon detection, and remaining measurement interference is now thought to be from 13C injected as 13CH molecule scattering off the plates of a second original pre-detector ESA.

  17. Nationwide Drinking Water Sampling Campaign for Exposure Assessments in Denmark

    Science.gov (United States)

    Voutchkova, Denitza Dimitrova; Hansen, Birgitte; Ernstsen, Vibeke; Kristiansen, Søren Munch

    2018-01-01

    Nationwide sampling campaign of treated drinking water of groundwater origin was designed and implemented in Denmark in 2013. The main purpose of the sampling was to obtain data on the spatial variation of iodine concentration and speciation in treated drinking water, which was supplied to the majority of the Danish population. This data was to be used in future exposure and epidemiologic studies. The water supply sector (83 companies, owning 144 waterworks throughout Denmark) was involved actively in the planning and implementation process, which reduced significantly the cost and duration of data collection. The dataset resulting from this collaboration covers not only iodine species (I−, IO3−, TI), but also major elements and parameters (pH, electrical conductivity, DOC, TC, TN, F−, Cl−, NO3−, SO42−, Ca2+, Mg2+, K+, Na+) and a long list of trace elements (n = 66). The water samples represent 144 waterworks abstracting about 45% of the annual Danish groundwater abstraction for drinking water purposes, which supply about 2.5 million Danes (45% of all Danish residents). This technical note presents the design, implementation, and limitations of such a sampling design in detail in order (1) to facilitate the future use of this dataset, (2) to inform future replication studies, or (3) to provide an example for other researchers. PMID:29518987

  18. UMTRA project water sampling and analysis plan, Durango, Colorado

    International Nuclear Information System (INIS)

    1994-01-01

    Surface remedial action has been completed at the Uranium Mill Tailings Remedial Action Project in Durango, Colorado. Contaminated soil and debris have been removed from the former processing site and placed in the Bodo Canyon disposal cell. Ground water at the former uranium mill/tailings site and raffinate pond area has been contaminated by the former milling operations. The ground water at the disposal site was not impacted by the former milling operations at the time of the cell's construction. Activities for fiscal 1994 involve ground water sampling and site characterization of the disposal site

  19. Design and analysis of a single stage to orbit nuclear thermal rocket reactor engine

    Energy Technology Data Exchange (ETDEWEB)

    Labib, Satira, E-mail: Satira.Labib@duke-energy.com; King, Jeffrey, E-mail: kingjc@mines.edu

    2015-06-15

    Graphical abstract: - Highlights: • Three NTR reactors are optimized for the single stage launch of 1–15 MT payloads. • The proposed rocket engines have specific impulses in excess of 700 s. • Reactivity and submersion criticality requirements are satisfied for each reactor. - Abstract: Recent advances in the development of high power density fuel materials have renewed interest in nuclear thermal rockets (NTRs) as a viable propulsion technology for future space exploration. This paper describes the design of three NTR reactor engines designed for the single stage to orbit launch of payloads from 1 to 15 metric tons. Thermal hydraulic and rocket engine analyses indicate that the proposed rocket engines are able to reach specific impulses in excess of 800 s. Neutronics analyses performed using MCNP5 demonstrate that the hot excess reactivity, shutdown margin, and submersion criticality requirements are satisfied for each NTR reactor. The reactors each consist of a 40 cm diameter core packed with hexagonal tungsten cermet fuel elements. The core is surrounded by radial and axial beryllium reflectors and eight boron carbide control drums. The 40 cm long reactor meets the submersion criticality requirements (a shutdown margin of at least $1 subcritical in all submersion scenarios) with no further modifications. The 80 and 120 cm long reactors include small amounts of gadolinium nitride as a spectral shift absorber to keep them subcritical upon submersion in seawater or wet sand following a launch abort.

  20. Heavy metal bioleaching and sludge stabilization in a single-stage reactor using indigenous acidophilic heterotrophs.

    Science.gov (United States)

    Mehrotra, Akanksha; Sreekrishnan, T R

    2017-11-01

    Simultaneous sludge digestion and metal leaching (SSDML) have been reported at mesophilic temperature. It is generally perceived that while sludge stabilization is effected by heterotrophs at neutral pH, metal bioleaching is done by acidophilic autotrophs. However, little information is available on the microbial communities involved in the process. This study carried out SSDML in a single-stage reactor using sludge indigenous microorganisms and looked at the bacterial communities responsible for the process. Volatile suspended solids were reduced by more than 40%. The concentration of zinc, copper, chromium, cadmium and nickel decreased by more than 45% in the dry sludge. Acidophilic species of Alicyclobacillus genus were the dominant heterotrophs. A few heterotrophic bacteria were detected which can oxidize iron (Alicyclobacillus ferrooxydans, Alicyclobacillus ferripilum and Ferrimicrobium acidiphilum). Acidithiobacillus ferrooxidans (autotroph) was responsible for the oxidation of both iron and sulfur which lead to a change in the pH from neutral to acidic. The presence of acidophilic heterotrophs, which can oxidize either iron or sulfur, enhanced the efficiency of SSDML process with respect to sludge stabilization and metal leaching. This study shows that it is possible to carry out the SSDML in a single-stage reactor with indigenous microorganisms.

  1. Red Mud Catalytic Pyrolysis of Pinyon Juniper and Single-Stage Hydrotreatment of Oils

    Energy Technology Data Exchange (ETDEWEB)

    Agblevor, Foster A.; Elliott, Douglas C.; Santosa, Daniel M.; Olarte, Mariefel V.; Burton, Sarah D.; Swita, Marie; Beis, Sedat H.; Christian, Kyle; Sargent, Brandon

    2016-10-20

    Pinyon juniper biomass feedstocks, which cover a large acreage of rangeland in the western United States, are being eradicated and, therefore, considered as a convenient biomass feedstock for biofuel production. Pinyon juniper whole biomass (wood, bark, and leaves) were pyrolyzed in a pilot-scale bubbling fluidized-bed reactor at 450 °C, and the noncondensable gases were recycled to fluidize the reactor. Red mud was used as the in situ catalyst for the pyrolysis of the pinyon juniper biomass. The pyrolysis products were condensed in three stages, and products were analyzed for physicochemical properties. The condenser oil formed two phases with the aqueous fraction, whereas the electrostatic precipitator oils formed a single phase. The oil pH was 3.3; the higher heating value (HHV) was 28 MJ/kg; and the viscosity was less than 100 cP. There was a direct correlation between the viscosity of the oils and the alcohol/ether content of the oils, and this was also related to the aging rate of the oils. The catalytic pyrolysis oils were hydrotreated in a continuous single-stage benchtop hydrotreater to produce hydrocarbon fuels with a density of 0.80$-$0.82 cm3/g. The hydrotreater ran continuously for over 300 h with no significant catalyst deactivation or coke formation. This is the first time that such a long single-stage hydrotreatment has been demonstrated on biomass catalytic pyrolysis oils.

  2. Single-stage micro-scale solvent extraction in parallel microbore tubes using MDIMJ

    International Nuclear Information System (INIS)

    Darekar, Mayur; Singh, K.K.; Joshi, J.M.; Mukhopadhyay, S.; Shenoy, K.T.

    2016-01-01

    Single-stage micro-scale solvent extraction of U(VI) from simulated lean streams is explored using micro-scale contactor comprising of a MDIMJ (Monoblock Distributor with Integrated Microfluidic Junction) and PTFE microbore tubes. 30% (v/v) TBP in dodecane has been used as the extracting phase. The objective of the study is to demonstrate numbering up approach for scale-up of micro-scale extraction using indigenously conceptualized and fabricated MDIMJ. First the performance of MIDIMJ for equal flow distribution is tested. Then the effects of inlet flow rate and O/A ratio on stage efficiency and percentage extraction are studied. The experiments show that it is easy to scale-up single-stage micro-scale solvent extraction by using MDIMJ for numbering up approach. Maximum capacity tested is 4.8 LPH. With O/A = 2/1, more than 90% extraction is achieved in a very short contact time of less than 3s. The study thus demonstrates possibility of process intensification and easy scale-up of micro-scale solvent extraction

  3. A single stage to orbit rocket with non-cryogenic propellants

    Science.gov (United States)

    Clapp, Mitchell B.; Hunter, Maxwell W.

    1993-06-01

    Different propellant combinations for single-stage-to-orbit-rocket applications were compared to oxygen/hydrogen, including nitrogen tetroxide/hydrazine, oxygen/methane, oxygen/propane, oxygen/RP-1, solid core nuclear/hydrogen, and hydrogen peroxide/JP-5. Results show that hydrogen peroxide and JP-5, which have a specific impulse of 328 s in vacuum and a density of 1,330 kg/cu m. This high-density jet fuel offers 1.79 times the payload specific energy of oxygen and hydrogen. By catalytically decomposing the hydrogen peroxide to steam and oxygen before injection into the thrust chamber, the JP-5 can be injected as a liquid into a high-temperature gas flow. This would yield superior combustion stability and permit easy throttling of the engine by adjusting the amount of JP-5 in the mixture. It is concluded that development of modern hydrogen peroxide/JP-5 engines, combined with modern structural technology, could lead to a simple, robust, and versatile single-stage-to-orbit capability.

  4. Performance evaluation of a piezoactuator-based single-stage valve system subjected to high temperature

    International Nuclear Information System (INIS)

    Jeon, Juncheol; Han, Chulhee; Ung Chung, Jye; Choi, Seung-Bok

    2015-01-01

    In this paper, a novel single-stage valve system activated by a piezostack actuator is proposed and experimentally evaluated at both room temperature (20 °C) and high temperature (100 °C) conditions. A hinge-lever displacement amplifier is adopted in the valve system to magnify the displacement generated from the piezostack actuator. After explaining the operating principle of the proposed piezostack-driven single-stage valve system, the geometric dimensions and mechanical properties of the valve components are discussed in details. An experimental apparatus is then manufactured to evaluate the performances of the valve system such as flow rate. The experimental apparatus consists of a heat chamber, which can regulate the temperature of the valve system and oil, pneumatic-hydraulic cylinders, a hydraulic circuit, a pneumatic circuit, electronic devices, an interface card, and a high voltage amplifier. The pneumatic-hydraulic cylinder transforms the pneumatic pressure into hydraulic pressure. The performances of the valve system regarding spool response, pressure drop, and flow rate are evaluated and presented. In addition, the performance of the valve system under high temperature condition is compared with that under room temperature condition. The experimental results are plotted in both frequency and time domains. (paper)

  5. Design and analysis of a radial diffuser in a single-stage centrifugal pump

    Directory of Open Access Journals (Sweden)

    Ming-Gao Tan

    2016-01-01

    Full Text Available Radial diffusers can improve the flow uniformity in pumps and affect the hydraulic performance of centrifugal pumps directly. The diffusion coefficient d is an important parameter in fluid machinery but it has seldom been used in the diffuser design of single-stage centrifugal pumps. To improve the design method of radial diffuser use in centrifugal pumps, the diffusion coefficient was introduced into the design of radial diffusers based on a single-arc hydraulic design method and it was found that the vane outlet angle, vane outlet thickness and vane number have a significant impact on the design results. A single-stage centrifugal pump with a radial diffuser was selected as the research model. The inner flow was simulated using the commercial computational fluid dynamics (CFD program CFX and verified by experiment. The results indicate that the head and efficiency of the pump are best when the vane outlet angle is 6°. The flow area decreases and the flow velocity at radial diffuser outlet increase when the outlet thickness is greater than 2 mm. The hydraulic loss is minimum and the head and efficiency are better when the vane number is 8 at different flow rates. So, the optimal range of the diffusion coefficient for the model pump is around 1.6 to 2. The study indicates that it is feasible to design radial diffusers according to the diffusion coefficient.

  6. Lengthening Temporalis Myoplasty for Single-Stage Smile Reconstruction in Children with Facial Paralysis.

    Science.gov (United States)

    Panossian, Andre

    2016-04-01

    Free muscle transfer for dynamic smile reanimation in facial paralysis is not always predictable with regard to cosmesis. Hospital stays range from 5 to 7 days. Prolonged operative times, longer hospital stays, and excessive cheek bulk are associated with free flap options. Lengthening temporalis myoplasty offers single-stage smile reanimation with theoretical advantages over free tissue transfer. From 2012 to 2014, 18 lengthening temporalis myoplasties were performed in 14 children for smile reconstruction. A retrospective chart review was completed for demographics, operative times, length of hospital stay, and perioperative complications. Fourteen consecutive patients with complete facial paralysis were included. Four patients underwent single-stage bilateral reconstruction, and 10 underwent unilateral procedures. Diagnoses included Möbius syndrome (n = 5), posterior cranial fossa tumors (n = 4), posttraumatic (n = 2), hemifacial microsomia (n = 1), and idiopathic (n = 2). Average patient age was 10.1 years. Average operative time was 410 minutes (499 minutes for bilateral lengthening temporalis myoplasty and 373 for unilateral lengthening temporalis myoplasty). Average length of stay was 3.3 days (4.75 days for bilateral lengthening temporalis myoplasty and 2.8 for unilateral lengthening temporalis myoplasty). Nine patients required minor revisions. Lengthening temporalis myoplasty is a safe alternative to free tissue transfer for dynamic smile reconstruction in children with facial paralysis. Limited donor-site morbidity, shorter operative times, and shorter hospital stays are some benefits over free flap options. However, revisions are required frequently secondary to tendon avulsions and adhesions. Therapeutic, IV.

  7. Hearing rehabilitation with single-stage bilateral vibroplasty in a child with Franceschetti syndrome.

    Science.gov (United States)

    Sargsyan, Sona; Rahne, Torsten; Kösling, Sabrina; Eichler, Gerburg; Plontke, Stefan K

    2014-05-01

    Hearing is of utmost importance for normal speech and social development. Even children who have mild or unilateral permanent hearing loss may experience difficulties with understanding speech, as well as problems with educational and psycho-social development. The increasing advantages of middle-ear implant technologies are opening new perspectives for restoring hearing. Active middle-ear implants can be used in children and adolescents with hearing loss. In addition to the well-documented results for improving speech intelligibility and quality of hearing in sensorineural hearing loss active middle-ear implants are now successfully used in patients with conductive and mixed hearing loss. In this article we present a case of successful, single-stage vibroplasty, on the right side with the fixation of the FMT on the stapes and PORP CLiP vibroplasty on the left side in a 6-year-old girl with bilateral mixed hearing loss and multiple dyslalia associated with Franceschetti syndrome (mandibulofacial dysostosis). CT revealed bilateral middle-ear malformations as well as an atretic right and stenotic left external auditory canal. Due to craniofacial dysmorphia airway and (post)operative, management is significantly more difficult in patients with a Franceschetti syndrome which in this case favoured a single-stage bilateral procedure. No intra- or postoperative surgical complications were reported. The middle-ear implants were activated 4 weeks after surgery. In the audiological examination 6 months after surgery, the child showed 100% speech intelligibility with activated implants on each side.

  8. In-situ sludge pretreatment in a single-stage anaerobic digester.

    Science.gov (United States)

    Chen, Yun; Xiao, Keke; Jiang, Xie; Shen, Nan; Zeng, Raymond J; Zhou, Yan

    2017-08-01

    This study aimed to develop an in-situ sludge pretreatment method by increasing the temperature from thermophilic to extreme thermophilic condition in a single-stage anaerobic digester. The results revealed that a stable performance was obtained within the temperature range of 55-65°C, and the maximum methane yield of 208.51±13.66mL/g VS was obtained at 65°C. Moreover, the maximum extent of hydrolysis (33%) and acidification (27.1%) was also observed at 65°C. However, further increase of temperature to 70°C did not improve the organic conversion efficiency. Microbial community analysis revealed that Coprothermobacter, highly related to acetate oxidisers, appeared to be the abundant bacterial group at higher temperature. A progressive shift in methanogenic members from Methanosarcina to Methanothermobacter was observed upon increasing the temperature. This work demonstrated single-stage sludge digestion system can be successfully established at high temperature (65°C) with stable performance, which can eliminate the need of conventional thermophilic pretreatment step. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Preconcentration of uranium in water samples using dispersive ...

    African Journals Online (AJOL)

    1-(2-Pyridylazo)-2-naphthol reagent (PAN) at pH 6.0 was used as a chelating agent prior to extraction. After concentration and purification of the samples in SPE C18 sorbent, 1.5 mL elution sample containing 40.0 µL chlorobenzene was injected into the 5.0 mL pure water. After extraction and centrifuging, the sedimented ...

  10. Water and steam sampling systems; Provtagningssystem foer vatten och aanga

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Mats

    2009-10-15

    The supervision of cycle chemistry can be divided into two parts, the sampling system and the chemical analysis. In modern steam generating plants most of the chemical analyses are carried out on-line. The detection limits of these analyzers are pushed downward to the ppt-range (parts per trillion), however the analyses are not more correct than the accuracy of the sampling system. A lot of attention has been put to the analyzers and the statistics to interpret the results but the sampling procedures has gained much less attention. This report aims to give guidance of the considerations to be made regarding sampling systems. Sampling is necessary since most analysis of interesting parameters cannot be carried out in- situ on-line in the steam cycle. Today's on-line instruments for pH, conductivity, silica etc. are designed to meet a water sample at a temperature of 10-30 deg C. This means that the sampling system has to extract a representative sample from the process, transport and cool it down to room temperature without changing the characteristics of the fluid. In the literature research work, standards and other reports can be found. Although giving similar recommendations in most aspects there are some discrepancies that may be confusing. This report covers all parts in the sampling system: Sample points and nozzles; Sample lines; Valves, regulating and on-off; Sample coolers; Temperature, pressure and flow rate control; Cooling water; and Water recovery. On-line analyzers connecting to the sampling system are not covered. This report aims to clarify what guidelines are most appropriate amongst the existing ones. The report should also give guidance to the design of the sampling system in order to achieve representative samples. In addition to this the report gives an overview of the fluid mechanics involved in sampling. The target group of this report is owners and operators of steam generators, vendors of power plant equipment, consultants working in

  11. Considerations on ultra trace analysis of carbamates in water samples.

    Science.gov (United States)

    Nogueira, J M F; Sandra, Tom; Sandra, Pat

    2003-05-09

    A new routine method for the ultra trace analysis of carbamates in water samples is presented, using solid-phase extraction followed by high-performance liquid chromatography coupled to atmospheric pressure electrospray ionisation mass spectrometry (SPE-LC-ESI-MS). Instrumental conditions of LC-ESI-MS in the selected ion monitoring (SIM) mode, showed excellent linear response for the six N-methyl carbamates studied (aldicarb, carbaryl, carbofuran, methomyl, oxamyl and pirimicarb) in the range from 1 to 50 microg/l and a precision having a relative standard deviation below 7.8% was achieved. Instrumental limits of detection of 0.10 microg/l were found for these carbamates, with the exception of methomyl for which 0.50 microg/l was measured. The SPE assays were shown to be easy, fast, very sensitive, requiring a low volume (50 ml) of water sample. For laboratory-spiked water samples having 0.03 and 0.30 microg/l of individual N-methyl carbamates, higher selectivities were achieved in cartridges having octadecylsilica, polystyrene-divinylbenzene and N-vinylpyrrolidane-divinylbenzene as solid phases, for which reasonable average recoveries were obtained. Ten replicates using octadecylsilica SPE cartridges, showed average recoveries between 73.7 and 92.6% with a relative standard deviation lower than 14.7%. The present methodology evidences good robustness, accuracy and precision for monitoring of N-methyl carbamates in water samples, and is shown to be a suitable alternative to replace the currently dedicated analytical systems. The limits of detection for the analysis of N-methyl carbamates in water samples reached in the present methodology (0.5 to 3 ng/l), clearly cover the maximum concentration admissible for pesticides, established by the European Union directive on water quality.

  12. Determination of estrogenic potential in waste water without sample extraction.

    Science.gov (United States)

    Avberšek, Miha; Žegura, Bojana; Filipič, Metka; Uranjek-Ževart, Nataša; Heath, Ester

    2013-09-15

    This study describes the modification of the ER-Calux assay for testing water samples without sample extraction (NE-(ER-Calux) assay). The results are compared to those obtained with ER-Calux assay and a theoretical estrogenic potential obtained by GC-MSD. For spiked tap and waste water samples there was no statistical difference between estrogenic potentials obtained by the three methods. Application of NE-(ER-Calux) to "real" influent and effluents from municipal waste water treatment plants and receiving surface waters found that the NE-(ER-Calux) assay gave higher values compared to ER-Calux assay and GC-MSD. This is explained by the presence of water soluble endocrine agonists that are usually removed during extraction. Intraday dynamics of the estrogenic potential of a WWTP influent and effluent revealed an increase in the estrogenic potential of the influent from 12.9 ng(EEQ)/L in the morning to a peak value of 40.0 ng(EEQ)/L in the afternoon. The estrogenic potential of the effluent was

  13. determination of thiobencarb in water samples by gas

    African Journals Online (AJOL)

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    ... liquid-liquid microextraction via flotation assistance (HLLME-FA) coupled with gas chromatography-flame ionization detection (GC-FID) was applied for the extraction and determination of thiobencarb in water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent ...

  14. Determination of thiobencarb in water samples by gas ...

    African Journals Online (AJOL)

    ... liquid-liquid microextraction via flotation assistance (HLLME-FA) coupled with gas chromatography-flame ionization detection (GC-FID) was applied for the extraction and determination of thiobencarb in water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent ...

  15. Determination of lead at nanogram level in water samples by ...

    African Journals Online (AJOL)

    A novel method of chemistry applicable to the determination of trace lead in water samples based on the resonance light scattering (RLS) technique has been developed. In dilute phosphoric acid medium, in the presence of a large excess of I-, Pb(II) can form [PbI4]2-, which further reacts with tetrabutyl ammonium bromide ...

  16. Levels of Cadmium in Soil, Sediment and Water Samples from ...

    African Journals Online (AJOL)

    Soil, sediment and water samples collected from the catchment areas of some selected rivers and streams in Tarkwa and its environs were investigated for the levels of cadmium using the Atomic Absorption spectrophometric technique. From the results, it was observed that cadmium levels were generally higher than the ...

  17. Selected radioisotopes` concentrations in integrated reactor effluent water samples

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, P.O.

    1962-12-01

    This document contains the results of weekly sampling of various isotope concentrations from effluent water at the 100 area at Hanford from July 1962 to February 1965. Compiled data in microcuries/milliliter are given. Each sampling records the concentrations of iodine-131, phosphorus-32, zinc-65, scandium-46, chromium-51, and cobalt-60. Records prior to October 8, 1962 also contain information on strontium-90, cesium-137, zirconium-95, ruthenium-103, ruthenium-106, and strontium-89. These last records are all from F reactor samples.

  18. Ground-water sample collection and analysis plan for the ground-water surveillance project

    International Nuclear Information System (INIS)

    Bryce, R.W.; Evans, J.C.; Olsen, K.B.

    1991-12-01

    The Pacific Northwest Laboratory performs ground-water sampling activities at the US Department of Energy's (DOE's) Hanford Site in support of DOE's environmental surveillance responsibilities. The purpose of this document is to translate DOE's General Environmental Protection Program (DOE Order 5400.1) into a comprehensive ground-water sample collection and analysis plan for the Hanford Site. This sample collection and analysis plan sets forth the environmental surveillance objectives applicable to ground water, identifies the strategy for selecting sample collection locations, and lists the analyses to be performed to meet those objectives

  19. A single-stage polymerase-based protocol for the introduction of deletions and insertions without subcloning.

    Science.gov (United States)

    Salerno, John C; Jones, Rachel J; Erdogan, Eda; Smith, Susan M E

    2005-03-01

    A single-stage polymerase-based procedure is described that allows extensive modifications of DNA. The version described here uses the QuikChange Site-Directed Mutagenesis System kit supplied by Stratagene. The original protocol is replaced by a single-stage method in which linear production of complementary strands is accomplished in separate single primer reactions. This has proved effective in introducing insertions and deletions into large gene/vector combinations without subcloning.

  20. Algae viability over time in a ballast water sample

    Science.gov (United States)

    Gollasch, Stephan; David, Matej

    2018-03-01

    The biology of vessels' ballast water needs to be analysed for several reasons, one of these being performance tests of ballast water management systems. This analysis includes a viability assessment of phytoplankton. To overcome logistical problems to get algae sample processing gear on board of a vessel to document algae viability, samples may be transported to land-based laboratories. Concerns were raised how the storage conditions of the sample may impact algae viability over time and what the most appropriate storage conditions were. Here we answer these questions with a long-term algae viability study with daily sample analysis using Pulse-Amplitude Modulated (PAM) fluorometry. The sample was analysed over 79 days. We tested different storage conditions: fridge and room temperature with and without light. It seems that during the first two weeks of the experiment the viability remains almost unchanged with a slight downwards trend. In the continuing period, before the sample was split, a slightly stronger downwards viability trend was observed, which occurred at a similar rate towards the end of the experiment. After the sample was split, the strongest viability reduction was measured for the sample stored without light at room temperature. We concluded that the storage conditions, especially regarding temperature and light exposure, have a stronger impact on algae viability compared to the storage duration and that inappropriate storage conditions reduce algal viability. A sample storage time of up to two weeks in a dark and cool environment has little influence on the organism viability. This indicates that a two week time duration between sample taking on board a vessel and the viability measurement in a land-based laboratory may not be very critical.

  1. Plasma gasification of refuse derived fuel in a single-stage system using different gasifying agents.

    Science.gov (United States)

    Agon, N; Hrabovský, M; Chumak, O; Hlína, M; Kopecký, V; Masláni, A; Bosmans, A; Helsen, L; Skoblja, S; Van Oost, G; Vierendeels, J

    2016-01-01

    The renewable evolution in the energy industry and the depletion of natural resources are putting pressure on the waste industry to shift towards flexible treatment technologies with efficient materials and/or energy recovery. In this context, a thermochemical conversion method of recent interest is plasma gasification, which is capable of producing syngas from a wide variety of waste streams. The produced syngas can be valorized for both energetic (heat and/or electricity) and chemical (ammonia, hydrogen or liquid hydrocarbons) end-purposes. This paper evaluates the performance of experiments on a single-stage plasma gasification system for the treatment of refuse-derived fuel (RDF) from excavated waste. A comparative analysis of the syngas characteristics and process yields was done for seven cases with different types of gasifying agents (CO2+O2, H2O, CO2+H2O and O2+H2O). The syngas compositions were compared to the thermodynamic equilibrium compositions and the performance of the single-stage plasma gasification of RDF was compared to that of similar experiments with biomass and to the performance of a two-stage plasma gasification process with RDF. The temperature range of the experiment was from 1400 to 1600 K and for all cases, a medium calorific value syngas was produced with lower heating values up to 10.9 MJ/Nm(3), low levels of tar, high levels of CO and H2 and which composition was in good agreement to the equilibrium composition. The carbon conversion efficiency ranged from 80% to 100% and maximum cold gas efficiency and mechanical gasification efficiency of respectively 56% and 95%, were registered. Overall, the treatment of RDF proved to be less performant than that of biomass in the same system. Compared to a two-stage plasma gasification system, the produced syngas from the single-stage reactor showed more favourable characteristics, while the recovery of the solid residue as a vitrified slag is an advantage of the two-stage set-up. Copyright

  2. Neutron activation analysis of trace elements in sea water samples

    International Nuclear Information System (INIS)

    Kusaka, Yuzuru; Tsuji, Haruo; Imai, Sakingo; Ohmori, Sayoko.

    1979-01-01

    Analytical values of trace elements in sea water samples have been fluctuated according to the sampling locations, the analytical procedures and so on. It is very important in marine chemistry to elucidate the cause of such concentration variations. This report is the analytical results of the samples obtained in the Pacific Ocean, the Indian Ocean and the Sea of Japan, by means of neutron activation analysis. As the preconcentration, 1-pyrrolidine carbothio acid (APDC)-chelate extraction and freeze-drying were adopted. The specimens obtained by this extraction from 500 or 800 ml samples were irradiated by KUR reactor for 1 min, 1 hr to 10 hrs and the gamma-ray spectrometry with a Ge(Li) detector was used for the determination of V, Mn, Cu, Zn, U, Fe, Co, Ni, Ag, Sb and Au. By about 80 hrs irradiation of the specimens obtained by freeze-drying from 20 ml samples and their gamma-ray spectrometry, Sc, Cr, Fe, Co, Zn, Rb, Sr, Ag, Sb and Cs were determined. The former procedure gives concentrations of elements in species reactable with APDC, but the latter method shows entire concentrations of the elements in the sea water samples. Some considerations on the analytical values and the comparisons of the both methods are described. (author)

  3. Collection and preparation of water samples for hydrogeochemical reconnaissance

    International Nuclear Information System (INIS)

    Baucom, E.I.; Ferguson, R.B.; Wallace, R.M.

    1977-01-01

    A method based on ion exchange and neutron activation analysis (NAA) was developed and field-tested to determine uranium over the range 0.02 to 10,000 ppb in natural water using a single procedure. Water samples are filtered in the field using a specially-designed one-liter filter apparatus pressurized to 40 psig with an inert gas. The filtered water is treated with a high purity, mixed cation-anion resin in the hydronium-hydroxide form. All ions are removed from solution under the strong driving force of the neutralization reaction. Anionic, cationic, and natural complexes of uranium can be concentrated with this method. Field tests showed greater than 95 percent recovery of 13 elements analyzed (including greater than 99 percent recovery of uranium) and greater than or equal to 90 percent recovery of 4 other elements. Uranium collected on the resin was quantitatively determined by NAA. Coefficient of variation for sampling plus analysis was less than 20 percent for samples containing more than 0.1 ppb uranium. Advantages of this method include: (1) wide dynamic range, (2) low detection limit for uranium (0.02 ppb), (3) high precision and accuracy, (4) relatively low cost, (5) high-yield recovery from low-level aqueous samples without risk of loss to containers, (6) decreased risk of significant sample contamination compared with other low-level methods, (7) production of stable samples suitable for retrievable storage, and(8) concentration of other ions that can be determined by NAA. This paper presents (1) background regarding development of procedures for sample collection and preparation, (2) results of development programs, (3) description of equipment and field procedures, and (4) preliminary conclusions regarding use of this technology for hydrogeochemical reconnaissance for uranium

  4. Magnesium isotope evidence for single stage formation of CB chondrules by colliding planetesimals

    DEFF Research Database (Denmark)

    Olsen, Mia Bjørg Stolberg; Schiller, Martin; Krot, Alexander N.

    2013-01-01

    Chondrules are igneous spherical objects preserved in chondritic meteorites and believed to have formed during transient heating events in the solar protoplanetary disk. Chondrules present in the metal-rich CB chondrites show unusual chemical and petrologic features not observed in other chondrite...... groups, implying a markedly distinct formation mechanism. Here, we report high-precision Mg-isotope data for 10 skeletal olivine chondrules from the Hammadah al Hamra 237 (HH237) chondrite to probe the formation history of CB chondrules. The Al/Mg ratios of individual chondrules are positively correlated...... to their stable Mg-isotope composition (μMg), indicating that the correlated variability was imparted by a volatility-controlled process (evaporation/condensation). The mass-independent Mg composition (μMg*) of chondrules is consistent with single stage formation from an initially homogeneous magnesium reservoir...

  5. Multi-disciplinary design optimization and performance evaluation of a single stage transonic axial compressor

    International Nuclear Information System (INIS)

    Lee, Sae Il; Lee, Dong Ho; Kim, Kyu Hong; Park, Tae Choon; Lim, Byeung Jun; Kang, Young Seok

    2013-01-01

    The multidisciplinary design optimization method, which integrates aerodynamic performance and structural stability, was utilized in the development of a single-stage transonic axial compressor. An approximation model was created using artificial neural network for global optimization within given ranges of variables and several design constraints. The genetic algorithm was used for the exploration of the Pareto front to find the maximum objective function value. The final design was chosen after a second stage gradient-based optimization process to improve the accuracy of the optimization. To validate the design procedure, numerical simulations and compressor tests were carried out to evaluate the aerodynamic performance and safety factor of the optimized compressor. Comparison between numerical optimal results and experimental data are well matched. The optimum shape of the compressor blade is obtained and compared to the baseline design. The proposed optimization framework improves the aerodynamic efficiency and the safety factor.

  6. Investigation of Single-Stage Modified Turbine of Mark 25 Torpedo Power Plant

    Science.gov (United States)

    Hoyt, Jack W.

    1947-01-01

    Efficiency investigations have been made on a single-stage modification of the turbine of a Mark 25 aerial torpedo to determine the performance of the unit with five different turbine nozzles. The output of the turbine blades was computed by analyzing the windage and mechanical-friction losses of the unit. The turbine was faund to be most efficient with a cast nozzle having sharp-edged inlets to the nine nozzle ports. An analysis af the effectiveness af the first and second stages of the standard Mark 25 torpedo turbine indicates that the first- stage turbine contributes nearly all the brake power produced at blade-jet speed ratios above 0.26.

  7. The Integrity of ACSR Full Tension Single-Stage Splice Connector at Higher Operation Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [ORNL; Lara-Curzio, Edgar [ORNL; King Jr, Thomas J [ORNL

    2008-10-01

    Due to increases in power demand and limited investment in new infrastructure, existing overhead power transmission lines often need to operate at temperatures higher than those used for the original design criteria. This has led to the accelerated aging and degradation of splice connectors. It is manifested by the formation of hot-spots that have been revealed by infrared imaging during inspection. The implications of connector aging is two-fold: (1) significant increases in resistivity of the splice connector (i.e., less efficient transmission of electricity) and (2) significant reductions in the connector clamping strength, which could ultimately result in separation of the power transmission line at the joint. Therefore, the splice connector appears to be the weakest link in electric power transmission lines. This report presents a protocol for integrating analytical and experimental approaches to evaluate the integrity of full tension single-stage splice connector assemblies and the associated effective lifetime at high operating temperature.

  8. Clean-chemistry synthesis of 2-tetralones in a single-stage acylation-cycloalkylation process.

    Science.gov (United States)

    Gray, A D; Smyth, T P

    2001-10-19

    The preparation of substituted-2-tetralones by direct reaction of a 1-alkene with a substituted phenylacetic acid in a reaction system of trifluoroacetic anhydride (TFAA) and phosphoric acid is described. This single-stage process involves in situ formation of a mixed anhydride of the phenylacetic acid and acylation of the alkene by this species followed by cycloalkylation of the aromatic ring. This is a cleaner approach to the synthesis of 2-tetralones compared to Friedel-Crafts aliphatic acylation-cycloalkylation in that use of thionyl chloride, aluminum trichloride, and a chlorinated hydrocarbon solvent is eliminated. In addition, the atom efficiency is augmented by recovery of the spent TFAA as trifluoroacetic acid (TFA) and conversion of this back to TFAA by dehydration.

  9. Theoretical evaluation of the efficiency of gas single-stage reciprocating compressor medium pressure units

    Science.gov (United States)

    Busarov, S. S.; Vasil'ev, V. K.; Busarov, I. S.; Titov, D. S.; Panin, Ju. N.

    2017-08-01

    Developed earlier and tested in such working fluid as air, the technology of calculating the operating processes of slow-speed long-stroke reciprocating stages let the authors to obtain successful results concerning compression of gases to medium pressures in one stage. In this connection, the question of the efficiency of the application of slow-speed long-stroke stages in various fields of technology and the national economy, where the working fluid is other gas or gas mixture, is topical. The article presents the results of the efficiency evaluation of single-stage compressor units on the basis of such stages for cases when ammonia, hydrogen, helium or propane-butane mixture is used as the working fluid.

  10. Isolated EWiRaC: A New Low-Stress Single-Stage Isolated PFC Converter

    DEFF Research Database (Denmark)

    Schneider, Henrik; Bergendorff, Stefan Pihl; Petersen, Lars

    2007-01-01

    A new PFC-family of Efficient Wide Range Converters named EWiRaC was recently introduced. EWiRaC has a major advantage in terms of efficiency at low-line and handles challenges like inrush current limiting as an integrated part of the conversion scheme. The main objective of this paper is to inve......A new PFC-family of Efficient Wide Range Converters named EWiRaC was recently introduced. EWiRaC has a major advantage in terms of efficiency at low-line and handles challenges like inrush current limiting as an integrated part of the conversion scheme. The main objective of this paper...... is to investigate the performance of an isolated EWiRaC (I-EWiRaC) in a single-stage PFC configuration....

  11. Realization of single-phase single-stage grid-connected PV system

    Directory of Open Access Journals (Sweden)

    Osama M. Arafa

    2017-05-01

    Full Text Available This paper presents a single phase single stage grid-tied PV system. Grid angle detection is introduced to allow operation at any arbitrary power factor but unity power factor is chosen to utilize the full inverter capacity. The system ensures MPPT using the incremental conductance method and it can track the changes in insolation level without oscillations. A PI voltage controller and a dead-beat current controller are used to ensure high quality injected current to the grid. The paper investigates the system structure and performance through numerical simulation using Matlab/Simulink. An experimental setup controlled by the MicrolabBox DSP prototyping platform is utilized to realize the system and study its performance. The precautions for smooth and safe system operation including the startup sequence are fully considered in the implementation.

  12. High efficiency 40 K single-stage Stirling-type pulse tube cryocooler

    Science.gov (United States)

    Wu, X. L.; Chen, L. B.; Pan, C. Z.; Cui, C.; Wang, J. J.; Zhou, Y.

    2017-12-01

    A high efficiency single-stage Stirling-type coaxial pulse tube cryocooler (SPTC) operating at around 40 K has been designed, built and tested. The double-inlet and the inertance tubes together with the gas reservoir were adopted as the phase shifters. Under the conditions of 2.5 MPa charging pressure and 30 Hz operating frequency, the prototype has achieved a no-load temperature of 23.8 K with 330 W of electric input power at a rejection temperature of 279 K. When the input power increases to 400 W, it can achieve a cooling capacity of 4.7 W/40 K while rejecting heat at 279 K yielding an efficiency of 7.02% relative to Carnot. It achieves a cooling capacity of 5 W/40 K with an input power of 450 W. It takes 10 minutes for the SPTC to cool to its no-load temperature of 40 K from 295 K.

  13. Self-Excited Single-Stage Power Factor Correction Driving Circuit for LED Lighting

    Directory of Open Access Journals (Sweden)

    Yong-Nong Chang

    2014-01-01

    Full Text Available This pa\tper proposes a self-excited single-stage high power factor LED lighting driving circuit. Being featured with power factor correction capability without needing any control devices, the proposed circuit structure is with low cost and suitable for commercial production. The power factor correction function is accomplished by using inductor in combination with a half-bridge quasi resonant converter to achieve active switching and yield out voltage regulation according to load requirement. Furthermore, the zero-voltage switching in the half-bridge converter can be attained to promote the overall performance efficiency of the proposed circuit. Finally, the validity and production availability of the proposed circuit will be verified as well.

  14. Detection of Brucella melitensis and Brucella abortus strains using a single-stage PCR method

    Directory of Open Access Journals (Sweden)

    Alamian, S.

    2015-04-01

    Full Text Available Brucella melitensis and Brucella abortus are of the most important causes of brucellosis, an infectious disease which is transmitted either directly or indirectly including consuming unpasteurized dairy products. Both strains are considered endemic in Iran. Common diagnostic methods such as bacteriologic cultures are difficult and time consuming regarding the bacteria. The aim of this study was to suggest a single-stage PCR method using a pair of primers to detect both B. melitensis and B. abortus. The primers were named UF1 and UR1 and the results showed that the final size of PCR products were 84 bp and 99 bp for B. melitensis and B. abortus, respectively. Therefore the method could be useful for rapid detection of B. melitensis and B. abortus simultaneously.

  15. Single stage to orbit mass budgets derived from propellant density and specific impulse

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, J.C.

    1996-06-06

    The trade between specific impulse (Isp) and density is examined in view of Single Stage To Orbit (SSTO) requirements. Mass allocations for vehicle hardware are derived from these two properties, for several propellant combinations and a dual-fuel case. This comparative analysis, based on flight-proven hardware, indicates that the higher density of several alternative propellants compensates for reduced Isp, when compared with cryogenic oxygen and hydrogen. Approximately half the orbiting mass of a rocket- propelled SSTO vehicle must be allocated to propulsion hardware and residuals. Using hydrogen as the only fuel requires a slightly greater fraction of orbiting mass for propulsion, because hydrogen engines and tanks are heavier than those for denser fuels. The advantage of burning both a dense fuel and hydrogen in succession depends strongly on tripropellant engine weight. The implications of the calculations for SSTO vehicle design are discussed, especially with regard to the necessity to minimize non-tankage structure.

  16. Single-stage management with combined tri-endoscopic approach for concomitant cholecystolithiasis and choledocholithiasis.

    Science.gov (United States)

    Lv, Fujing; Zhang, Shutian; Ji, Ming; Wang, Yongjun; Li, Peng; Han, Wei

    2016-12-01

    The aim of this study was to investigate the value of a single stage with combined tri-endoscopic (duodenoscopy, laparoscopy and choledochoscopy) approach for patients with concomitant cholecystolithiasis and choledocholithiasis. Fifty-three patients with combined gallbladder stones and common bile duct stones from February 2014 to April 2015 were randomized assigned to two groups: 29 patients underwent single-stage surgery with combined duodenoscope, laparoscope and choledochoscope (combined tri-endoscopic group), and 29 patients underwent endoscopic sphincterotomy to remove common bile duct stones followed by laparoscopic cholecystectomy several days later (control group). The success rate of complete stone removal, procedure-related complication, hospital stay and the cost of hospitalization were compared between the two groups. Altogether, 53 patients (29 patients in combined tri-endoscopic group and 24 patients in control group) successfully underwent the surgery and ERCP procedure. Three patients in the control group developed post-ERCP pancreatitis. One case of bile leaking and one case of residual stone were noted in the combined tri-endoscopic group. There were no significant differences between the two groups with regard to both complete stone removal [96.6 % (28/29) vs. 100 % (24/24)] and procedure-related complication rate [3.4 % (1/29) vs. 12.5 % (3/24)] (p > 0.05). No open surgery was required in either group. There were significant differences between the two groups with regard to hospital stay (6.72 ± 1.3 days vs. 10.91 ± 1.6 days, p choledocholithiasis was just as safe and successful as the control group. In addition, it resulted in a shorter hospital stay and less cost.

  17. Outcome of single stage vertebral column resection in treatment of kyphotic deformity.

    Science.gov (United States)

    Arif, Mohammad; Satar, Abdul; Saeed, Muhammad; Wazir, Zahid; Inam, Mohammad

    2014-12-01

    To find the frequency of deformity correction, functional outcome and complications of single-stage vertebral column resection in patients with kyphotic deformity. The prospective case series was conducted at Hayatabad Medical Complex, Peshawar, and Aman Hospital, Peshawar, from January 2012 to December 2013, and comprised all patients who underwent single-stage posterior vertebral column resection. Only patients with severe rigid sharp deformity of different aetiology that required more than 40 degree correction and who had at least 3-month follow-up were included. Data was processed using SPSS 16. Of the total 18 patients, 11(61.1%) were male and 7(38.9%) were female, with an overall mean age of 28.7±13.6 years (range: 12-60 years). Among them, 8(44.4%) patients had congenital kyphosis, 5(27.8%) had posttraumatic origin, 4(22.2%) had post-tuberculous deformity, while 1(5.6%) had iatrogenic kyphosis. The apex of the deformity was in thoracic spine in 12(66.7%) patients, while in 6(33.3%) patients it was in the lumbar spine. The average pre- and post-operative Cobb's angle was 66.2±18.9 degrees and 18.8±12.8 degrees respectively. Mean correction of deformities was 47.3±13.3 degrees. The mean correction achieved in percentage terms was 73.5±8.6 per cent (range: 56-87%). There were no patients with post-operative deterioration of neurological status. Two (11%) patients underwent re-exploration of the wounds with wash and cultures due to wound discharge. Posterior vertebral column resection was found to be a very effective method of correction of severe kyphotic deformities in expert hands with acceptable morbidity.

  18. Comparisons of single-stage and two-stage approaches to genomic selection.

    Science.gov (United States)

    Schulz-Streeck, Torben; Ogutu, Joseph O; Piepho, Hans-Peter

    2013-01-01

    Genomic selection (GS) is a method for predicting breeding values of plants or animals using many molecular markers that is commonly implemented in two stages. In plant breeding the first stage usually involves computation of adjusted means for genotypes which are then used to predict genomic breeding values in the second stage. We compared two classical stage-wise approaches, which either ignore or approximate correlations among the means by a diagonal matrix, and a new method, to a single-stage analysis for GS using ridge regression best linear unbiased prediction (RR-BLUP). The new stage-wise method rotates (orthogonalizes) the adjusted means from the first stage before submitting them to the second stage. This makes the errors approximately independently and identically normally distributed, which is a prerequisite for many procedures that are potentially useful for GS such as machine learning methods (e.g. boosting) and regularized regression methods (e.g. lasso). This is illustrated in this paper using componentwise boosting. The componentwise boosting method minimizes squared error loss using least squares and iteratively and automatically selects markers that are most predictive of genomic breeding values. Results are compared with those of RR-BLUP using fivefold cross-validation. The new stage-wise approach with rotated means was slightly more similar to the single-stage analysis than the classical two-stage approaches based on non-rotated means for two unbalanced datasets. This suggests that rotation is a worthwhile pre-processing step in GS for the two-stage approaches for unbalanced datasets. Moreover, the predictive accuracy of stage-wise RR-BLUP was higher (5.0-6.1%) than that of componentwise boosting.

  19. Hexagonal ice in pure water and biological NMR samples

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Thomas; Gath, Julia; Hunkeler, Andreas; Ernst, Matthias, E-mail: maer@ethz.ch [ETH Zurich, Physical Chemistry (Switzerland); Böckmann, Anja, E-mail: a.bockmann@ibcp.fr [UMR 5086 CNRS, Université de Lyon 1, Institut de Biologie et Chimie des Protéines (France); Meier, Beat H., E-mail: beme@ethz.ch [ETH Zurich, Physical Chemistry (Switzerland)

    2017-01-15

    Ice, in addition to “liquid” water and protein, is an important component of protein samples for NMR spectroscopy at subfreezing temperatures but it has rarely been observed spectroscopically in this context. We characterize its spectroscopic behavior in the temperature range from 100 to 273 K, and find that it behaves like pure water ice. The interference of magic-angle spinning (MAS) as well as rf multiple-pulse sequences with Bjerrum-defect motion greatly influences the ice spectra.

  20. Monolith Chromatography as Sample Preparation Step in Virome Studies of Water Samples.

    Science.gov (United States)

    Gutiérrez-Aguirre, Ion; Kutnjak, Denis; Rački, Nejc; Rupar, Matevž; Ravnikar, Maja

    2018-01-01

    Viruses exist in aquatic media and many of them use this media as transmission route. Next-generation sequencing (NGS) technologies have opened new doors in virus research, allowing also to reveal a hidden diversity of viral species in aquatic environments. Not surprisingly, many of the newly discovered viruses are found in environmental fresh and marine waters. One of the problems in virome research can be the low amount of viral nucleic acids present in the sample in contrast to the background ones (host, eukaryotic, prokaryotic, environmental). Therefore, virus enrichment prior to NGS is necessary in many cases. In water samples, an added problem resides in the low concentration of viruses typically present in aquatic media. Different concentration strategies have been used to overcome such limitations. CIM monoliths are a new generation of chromatographic supports that due to their particular structural characteristics are very efficient in concentration and purification of viruses. In this chapter, we describe the use of CIM monolithic chromatography for sample preparation step in NGS studies targeting viruses in fresh or marine water. The step-by-step protocol will include a case study where CIM concentration was used to study the virome of a wastewater sample using NGS.

  1. Fluoroquinolone antibiotics in environmental waters: sample preparation and determination.

    Science.gov (United States)

    Speltini, Andrea; Sturini, Michela; Maraschi, Federica; Profumo, Antonella

    2010-04-01

    The aim of this review is to provide a general overview on the analytical methods proposed in the last decade for trace fluoroquinolone (FQ) determination in environmental waters. A large number of studies have been developed on this topic in reason of the importance of their monitoring in the studies of environmental mobility and potential degradation pathways. Every step of the analysis has been carefully considered, with a particular attention to sample preparation, in relationship with the problems involved in the analysis of real matrices. The different strategies to minimise interference from organic matter and to achieve optimal sensitivity, especially important in those samples with lower FQ concentrations, were also highlighted. Results and progress in this field have been described and critically commented. Moreover, a worldwide overview on the presence of FQs in the environmental waters has been reported.

  2. An opacity-sampled treatment of water vapor

    Science.gov (United States)

    Alexander, David R.; Augason, Gordon C.; Johnson, Hollis R.

    1989-01-01

    Although the bands of H2O are strong in the spectra of cool stars and calculations have repeatedly demonstrated their significance as opacity sources, only approximate opacities are currently available, due both to the difficulty of accounting for the millions of lines involved and to the inadequacy of laboratory and theoretical data. To overcome these obstacles, a new treatment is presented, based upon a statistical representation of the water vapor spectrum derived from available laboratory data. This statistical spectrum of water vapor employs an exponential distribution of line strengths and random positions of lines whose overall properties are forced to reproduce the mean opacities observed in the laboratory. The resultant data set is then treated by the opacity-sampling method exactly as are all other lines, both molecular and atomic. Significant differences are found between the results of this improved treatment and the results obtained with previous treatments of water-vapor opacity.

  3. RAPID SEPARATION METHOD FOR EMERGENCY WATER AND URINE SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.; Culligan, B.

    2008-08-27

    The Savannah River Site Environmental Bioassay Lab participated in the 2008 NRIP Emergency Response program administered by the National Institute for Standards and Technology (NIST) in May, 2008. A new rapid column separation method was used for analysis of actinides and {sup 90}Sr the NRIP 2008 emergency water and urine samples. Significant method improvements were applied to reduce analytical times. As a result, much faster analysis times were achieved, less than 3 hours for determination of {sup 90}Sr and 3-4 hours for actinides. This represents a 25%-33% improvement in analysis times from NRIP 2007 and a {approx}100% improvement compared to NRIP 2006 report times. Column flow rates were increased by a factor of two, with no significant adverse impact on the method performance. Larger sample aliquots, shorter count times, faster cerium fluoride microprecipitation and streamlined calcium phosphate precipitation were also employed. Based on initial feedback from NIST, the SRS Environmental Bioassay Lab had the most rapid analysis times for actinides and {sup 90}Sr analyses for NRIP 2008 emergency urine samples. High levels of potential matrix interferences may be present in emergency samples and rugged methods are essential. Extremely high levels of {sup 210}Po were found to have an adverse effect on the uranium results for the NRIP-08 urine samples, while uranium results for NRIP-08 water samples were not affected. This problem, which was not observed for NRIP-06 or NRIP-07 urine samples, was resolved by using an enhanced {sup 210}Po removal step, which will be described.

  4. GROUND WATER SAMPLING OF VOCS IN THE WATER/CAPILLARY FRINGE AREA FOR VAPOR INTRUSION ASSESSMENT

    Science.gov (United States)

    Vapor intrusion has recently been considered a major pathway for increased indoor air contamination from certain volatile organic contaminants (VOCs). The recent Draft EPA Subsurface Vapor Intrusion Guidance Document states that ground water samples should be obtained from the u...

  5. Monitoring of fluoride in water samples using a smartphone

    International Nuclear Information System (INIS)

    Levin, Saurabh; Krishnan, Sunderrajan; Rajkumar, Samuel; Halery, Nischal; Balkunde, Pradeep

    2016-01-01

    In several parts of India, groundwater is the only reliable, year round source for drinking water. Prevention of fluorosis, a chronic disease resulting from excess intake of fluoride, requires the screening of all groundwater sources for fluoride in endemic areas. In this paper, the authors present a field deployable colorimetric analyzer based on an inexpensive smartphone embedded with digital camera for taking photograph of the colored solution as well as an easy-fit, and compact sample chamber (Akvo Caddisfly). Phones marketed by different smartphone makers were used. Commercially available zirconium xylenol orange reagent was used for determining fluoride concentration. A software program was developed to use with the phone for recording and analyzing the RGB color of the picture. Linear range for fluoride estimation was 0–2 mg l −1 . Around 200 samples, which consisted of laboratory prepared as well as field samples collected from different locations in Karnataka, India, were tested with Akvo Caddisfly. The results showed a significant positive correlation between Ion Selective Electrode (ISE) method and Akvo Caddisfly (Phones A, B and C), with correlation coefficient ranging between 0.9952 and 1.000. In addition, there was no significant difference in the mean fluoride content values between ISE and Phone B and C except for Phone A. Thus the smartphone method is economical and suited for groundwater fluoride analysis in the field. - Highlights: • Fluoride is an inorganic pollutant in ground water, affecting human health. • A colorimetric method for measurement of fluoride in drinking water with smartphone • Measurement is by mixing water with zirconyl xylenol orange complex reagent. • Results are comparable with laboratory-based ion selective fluoride electrode method.

  6. Monitoring of fluoride in water samples using a smartphone

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Saurabh [Akvo Foundation (Netherlands); Krishnan, Sunderrajan [INREM Foundation (India); Rajkumar, Samuel; Halery, Nischal; Balkunde, Pradeep [Akvo Foundation (Netherlands)

    2016-05-01

    In several parts of India, groundwater is the only reliable, year round source for drinking water. Prevention of fluorosis, a chronic disease resulting from excess intake of fluoride, requires the screening of all groundwater sources for fluoride in endemic areas. In this paper, the authors present a field deployable colorimetric analyzer based on an inexpensive smartphone embedded with digital camera for taking photograph of the colored solution as well as an easy-fit, and compact sample chamber (Akvo Caddisfly). Phones marketed by different smartphone makers were used. Commercially available zirconium xylenol orange reagent was used for determining fluoride concentration. A software program was developed to use with the phone for recording and analyzing the RGB color of the picture. Linear range for fluoride estimation was 0–2 mg l{sup −1}. Around 200 samples, which consisted of laboratory prepared as well as field samples collected from different locations in Karnataka, India, were tested with Akvo Caddisfly. The results showed a significant positive correlation between Ion Selective Electrode (ISE) method and Akvo Caddisfly (Phones A, B and C), with correlation coefficient ranging between 0.9952 and 1.000. In addition, there was no significant difference in the mean fluoride content values between ISE and Phone B and C except for Phone A. Thus the smartphone method is economical and suited for groundwater fluoride analysis in the field. - Highlights: • Fluoride is an inorganic pollutant in ground water, affecting human health. • A colorimetric method for measurement of fluoride in drinking water with smartphone • Measurement is by mixing water with zirconyl xylenol orange complex reagent. • Results are comparable with laboratory-based ion selective fluoride electrode method.

  7. Attainability and minimum energy of single-stage membrane and membrane/distillation hybrid processes

    KAUST Repository

    Alshehri, Ali

    2014-12-01

    As an energy-efficient separation method, membrane technology has attracted more and more attentions in many challenging separation processes. The attainability and the energy consumption of a membrane process are the two basic fundamental questions that need to be answered. This report aims to use process simulations to find: (1) at what conditions a single-stage membrane process can meet the separation task that is defined by product purity and recovery ratio and (2) what are the most important parameters that determine the energy consumption. To perform a certain separation task, it was found that both membrane selectivity and pressure ratio exhibit a minimum value that is defined only by product purity and recovery ratio. The membrane/distillation hybrid system was used to study the energy consumption. A shortcut method was developed to calculate the minimum practical separation energy (MPSE) of the membrane process and the distillation process. It was found that the MPSE of the hybrid system is only determined by the membrane selectivity and the applied transmembrane pressure ratio in three stages. At the first stage when selectivity is low, the membrane process is not competitive to the distillation process. Adding a membrane unit to a distillation tower will not help in reducing energy. At the second medium selectivity stage, the membrane/distillation hybrid system can help reduce the energy consumption, and the higher the membrane selectivity, the lower is the energy. The energy conservation is further improved as pressure ratio increases. At the third stage when both selectivity and pressure ratio are high, the hybrid system will change to a single-stage membrane unit and this change will cause significant reduction in energy consumption. The energy at this stage keeps decreasing with selectivity at slow rate, but slightly increases with pressure ratio. Overall, the higher the membrane selectivity, the more the energy is saved. Therefore, the two

  8. Differences in microbial community composition between injection and production water samples of water flooding petroleum reservoirs

    Directory of Open Access Journals (Sweden)

    P. K. Gao

    2015-06-01

    Full Text Available Microbial communities in injected water are expected to have significant influence on those of reservoir strata in long-term water flooding petroleum reservoirs. To investigate the similarities and differences in microbial communities in injected water and reservoir strata, high-throughput sequencing of microbial partial 16S rRNA of the water samples collected from the wellhead and downhole of injection wells, and from production wells in a homogeneous sandstone reservoir and a heterogeneous conglomerate reservoir were performed. The results indicate that a small number of microbial populations are shared between the water samples from the injection and production wells in the sandstone reservoir, whereas a large number of microbial populations are shared in the conglomerate reservoir. The bacterial and archaeal communities in the reservoir strata have high concentrations, which are similar to those in the injected water. However, microbial population abundance exhibited large differences between the water samples from the injection and production wells. The number of shared populations reflects the influence of microbial communities in injected water on those in reservoir strata to some extent, and show strong association with the unique variation of reservoir environments.

  9. Nuclear power plants and the environment. Water samplings and releases

    International Nuclear Information System (INIS)

    Hartmann, Philippe; Bordet, Francois; Chevalier, Christian; Colin, Jean-Luc; Khalanski, Michel

    2013-01-01

    This voluminous and illustrated guide aims at giving detailed information on the nature of waters used by nuclear power plants and of releases, on how these samplings and controls are performed, on the associated risks for the environment and public health, and on how public is informed. After a general overview of these issues, a chapter addresses the protection of nature and biodiversity and the actions performed by EDF in this respect. The next chapter deals with public information. The next chapters discuss the water needs of a nuclear power plant, effluent releases and their impacts. Two chapters are dedicated to the monitoring and control of the environment, and to the various techniques of environmental metrology. Legal and regulatory aspects are then presented

  10. Outcomes of single-stage total arch replacement via clamshell incision

    Directory of Open Access Journals (Sweden)

    Ishizaka Toru

    2011-09-01

    Full Text Available Abstract Background Treatment of complex aortic pathologies involving the transverse arch with extensive involvement of the descending aorta remains a surgical challenge. Since clamshell incision provides superior exposure of the entire thoracic aorta, we evaluated the use of this technique for single-stage total arch replacement by arch vessel reconstruction. Methods The arch-first technique combined with clamshell incision was used in 38 cases of aneurysm and aortic disease in 2008 and 2009. Extensive total arch replacement was used with clamshell incision for reconstruction of arch vessels under deep hypothermic circulatory arrest. Results Overall 30-day mortality was 13%. The mean operating time was approximately 8 hours. Deep hypothermia resulted in mean CPB time exceeding 4.5 hours and mean duration of circulatory arrest was 25 minutes. The overall postoperative temporary and permanent neurologic dysfunction rates were 3% and 3% for elective and 3% and 0% for emergency surgery, respectively. All patients except the five who died in hospital were discharged without nursing care after an average post-operative hospital stay of 35 days. Conclusions The arch-first technique, combined with clamshell incision, provides expeditious replacement of the thoracic aorta with an acceptable duration of hypothermic circulatory arrest and minimizes the risk of retrograde atheroembolism by using antegrade perfusion.

  11. Solvent Carryover Characterization and Recovery for a 10-inch Single Stage Centrifugal Contactor

    International Nuclear Information System (INIS)

    Lentsch, R.D.; Stephens, A.B.; Leung, D.T.; Baffling, K.E.; Harmon, H.D.; Suggs, P.C.

    2006-01-01

    A test program has been performed to characterize the organic solvent carryover and recovery from centrifugal contactors in the Caustic-side Solvent Extraction (CSSX) process. CSSX is the baseline design for removing cesium from salt solutions for Department of Energy (DOE) Savannah River Site's Salt Waste Processing Facility. CSSX uses a custom solvent to extract cesium from the salt solution in a series of single stage centrifugal contactors. Meeting the Waste Acceptance Criteria at the Defense Waste Processing Facility and Saltstone, as well as plant economics, dictate that solvent loss should be kept to a minimum. Solvent droplet size distribution in the aqueous outlet streams of the CSSX contactors is of particular importance to the design of solvent recovery equipment. Because insufficient solvent droplet size data existed to form a basis for the recovery system design, DOE funded the CSSX Solvent Carryover Characterization and Recovery Test (SCCRT). This paper presents the droplet size distribution of solvent and concentration in the contactor aqueous outlet streams as a function of rotor speed, bottom plate type, and flow rate. It also presents the performance data of a prototype coalescer. (authors)

  12. Single-Stage Step up/down Driver for Permanent-Magnet Synchronous Machines

    Science.gov (United States)

    Chen, T. R.; Juan, Y. L.; Huang, C. Y.; Kuo, C. T.

    2017-11-01

    The two-stage circuit composed of a step up/down dc converter and a three-phase voltage source inverter is usually adopted as the electric vehicle’s motor driver. The conventional topology is more complicated. Additional power loss resulted from twice power conversion would also cause lower efficiency. A single-stage step up/down Permanent-Magnet Synchronous Motor driver for Brushless DC (BLDC) Motor is proposed in this study. The number components and circuit complexity are reduced. The low frequency six-step square-wave control is used to reduce the switching losses. In the proposed topology, only one active switch is gated with a high frequency PWM signal for adjusting the rotation speed. The rotor position signals are fed back to calculate the motor speed for digital close-loop control in a MCU. A 600W prototype circuit is constructed to drive a BLDC motor with rated speed 3000 rpm, and can control the speed of six sections.

  13. Single-stage Kanban system with deterioration failures and condition-based preventive maintenance

    International Nuclear Information System (INIS)

    Xanthopoulos, A.S.; Koulouriotis, D.E.; Botsaris, P.N.

    2015-01-01

    Despite the fact that the fields of pull type production control policies and condition-based preventive maintenance have much in common contextually, they have evolved independently up to now. In this investigation, an attempt is made to bridge the gap between these two branches of knowledge by introducing the single-stage Kanban system with deterioration failures and condition-based preventive maintenance. The formalism of continuous time Markov chains is used to model the system and expressions for eight performance metrics are derived. Two important, from a managerial perspective, constrained optimization problems for the proposed model are defined where the objective is the simultaneous optimization of the Kanban policy, the preventive maintenance policy and the inspection schedule under conflicting performance criteria. Multiple instances of each optimization problem are solved by means of the augmented Lagrangian genetic algorithm. The results from the optimization trials coupled by the results from extensive numerical examples facilitate the thorough investigation of the system’s behaviour. - Highlights: • Kanban system with deterioration failures and preventive maintenance is introduced. • The system is modeled as a continuous time Markov chain. • Expressions for eight performance metrics are derived. • The behavior of the system is studied through numerical examples. • Optimization results for selected performance metrics are presented

  14. Single stage: dorsolateral onlay buccal mucosal urethroplasty for long anterior urethral strictures using perineal route

    Directory of Open Access Journals (Sweden)

    Vikram Prabha

    2016-06-01

    Full Text Available ABSTRACT Objective To assess the outcome of single stage dorsolateral onlay buccal mucosal urethroplasty for long anterior urethral strictures (>4cm long using a perineal incision. Materials and Methods From August 2010 to August 2013, 20 patients underwent BMG urethroplasty. The cause of stricture was Lichen sclerosis in 12 cases (60%, Instrumentation in 5 cases (25%, and unknown in 3 cases (15%. Strictures were approached through a perineal skin incision and penis was invaginated into it to access the entire urethra. All the grafts were placed dorsolaterally, preserving the bulbospongiosus muscle, central tendon of perineum and one-sided attachement of corpus spongiosum. Procedure was considered to be failure if the patient required instrumentation postoperatively. Results Mean stricture length was 8.5cm (range 4 to 12cm. Mean follow-up was 22.7 months (range 12 to 36 months. Overall success rate was 85%. There were 3 failures (meatal stenosis in 1, proximal stricture in 1 and whole length recurrent stricture in 1. Other complications included wound infection, urethrocutaneous fistula, brownish discharge per urethra and scrotal oedema. Conclusion Dorsolateral buccal mucosal urethroplasty for long anterior urethral strictures using a single perineal incision is simple, safe and easily reproducible by urologists with a good outcome.

  15. [Achieve single-stage autotrophic biological nitrogen removal process by controlling the concentration of free ammonia].

    Science.gov (United States)

    Ji, Li-Li; Yang, Zhao-Hui; Xu, Zheng-Yong; Li, Xiao-Jiang; Tang, Zhi-Gang; Deng, Jiu-Hu

    2011-01-01

    Through controlling the concentration of free ammonia in the sequencing batch reactor (SBR), the single-stage autotrophic biological nitrogen removal process was achieved, including partial nitrification and anaerobic ammonium oxidation. The experiment was completed via two steps, the enrichment of nitrite bacteria and the inoculation of the mixture of anammox biomass. The operating temperature in the SBR was (31 +/- 2) degrees C. During the step of the enrichment of nitrite bacteria, pH was about 7.8. Changes of FA concentration were achieved by controlling the concentration of influent NH4(+) -N(56-446 mg x L(-1)), in order to inhibit and eliminate the nitrate bacteria. The activity tests of the sludge, 55d after enrichment, showed strong activity of aerobic ammonium oxidation [2.91 kg x (kg x d)(-1)] and low activity of nitrite oxidation [0.03 kg x(kg x d)(-1)]. During the inoculation of the mixture of anammox biomass, changes of FA concentration were achieved by controlling the concentration of influent NH4(+) -N and pH. As the inoculation of anammox biomass, abundant of bacteria and nutrient content were into the reactor and there kept high activity of aerobic ammonium oxidation [2.83 kg x (kg x d)(-1)] and a certain activity of nitrite oxidation, at the same time, the activity of anammox and heterotrophic denitrification reached 0.65 kg x (kg x d)(-1) and 0.11 kg x (kg x d)(-1), respectively.

  16. Wind-driven SEIG supplying DC microgrid through a single-stage power converter

    Directory of Open Access Journals (Sweden)

    Vellapatchi Nayanar

    2016-09-01

    Full Text Available Nowadays, there is an increased emphasis on utilizing the renewable energy sources and selection of suitable power converters for supplying dc microgrid. Among the various renewable energy sources, wind energy stands first in terms of installed capacity. So, an attempt is made in this paper for supplying dc microgrid utilizing wind energy. A self-excited induction generator has been used in the proposed wind energy conversion system (WECS. A single-stage power converter, namely, semi-converter is connected between the SEIG and dc grid terminals for closed-loop control of the proposed system. A perturb and observe (P&O based maximum power point tracking (MPPT algorithm has been developed and implemented using a dsPIC30F4011 digital controller. In this MPPT algorithm, the firing angle of the converter is adjusted by continuously monitoring the dc grid current for a given wind velocity. For analyzing the proposed system, a MATLAB/Simulink model has been developed by selecting the various components starting from wind-turbine model to the power converter supplying dc microgrid. Successful working of the proposed WECS has also been shown through experimental results obtained on a prototype model developed in the laboratory.

  17. Construction and characterization of a single stage dual diaphragm gas gun

    Science.gov (United States)

    Helminiak, Nathaniel Steven

    In the interest of studying the propagation of shock waves, this work sets out to design, construct, and characterize a pneumatic accelerator that performs high-velocity flyer plate impact tests. A single stage gas gun with a dual diaphragm breach allows for a non-volatile, reliable experimental testing platform for shock phenomena. This remotely operated gas gun utilizes compressed nitrogen to launch projectiles down a 14 foot long, 2 inch diameter bore barrel, which subsequently impacts a target material of interest. A dual diaphragm firing mechanism allows the 4.5 liter breech to reach a total pressure differential of 10ksi before accelerating projectiles to velocities as high as 1,000 m/s (1570-2240 mph). The projectile's velocity is measured using a series of break pin circuits. The target response can be measured with Photon Doppler Velocimetry (PDV) and/or stress gauge system. A vacuum system eliminates the need for pressure relief in front of the projectile, while additionally allowing the system to remain closed over the entire firing cycle. Characterization of the system will allow for projectile speed to be estimated prior to launching based on initial breach pressure.

  18. Orifice Mass Flow Calculation in NASA's W-8 Single Stage Axial Compressor Facility

    Science.gov (United States)

    Bozak, Richard F.

    2018-01-01

    Updates to the orifice mass flow calculation for the W-8 Single Stage Axial Compressor Facility at NASA Glenn Research Center are provided to include the effect of humidity and incorporate ISO 5167. A methodology for including the effect of humidity into the inlet orifice mass flow calculation is provided. Orifice mass flow calculations provided by ASME PTC-19.5-2004, ASME MFC-3M-2004, ASME Fluid Meters, and ISO 5167 are compared for W-8's atmospheric inlet orifice plate. Differences in expansion factor and discharge coefficient given by these standards give a variation of about +/- 75% mass flow except for a few cases. A comparison of the calculations with an inlet static pressure mass flow correlation and a fan exit mass flow integration using test data from a 2017 turbofan rotor test in W-8 show good agreement between the inlet static pressure mass flow correlation, ISO 5167, and ASME Fluid Meters. While W-8's atmospheric inlet orifice plate violates the pipe diameter limit defined by each of the standards, the ISO 5167 is chosen to be the primary orifice mass flow calculation to use in the W-8 facility.

  19. Single-stage transforaminal decompression, debridement, interbody fusion, and posterior instrumentation for lumbosacral brucellosis.

    Science.gov (United States)

    Abulizi, Yakefu; Liang, Wei-Dong; Muheremu, Aikeremujiang; Maimaiti, Maierdan; Sheng, Wei-Bin

    2017-07-14

    Spinal brucellosis is a less commonly reported infectious spinal pathology. There are few reports regarding the surgical treatment of spinal brucellosis in existing literature. This retrospective study was conducted to determine the effectiveness of single-stage transforaminal decompression, debridement, interbody fusion, and posterior instrumentation for lumbosacral spinal brucellosis. From February 2012 to April 2015, 32 consecutive patients (19 males and 13 females, mean age 53.7 ± 8.7) with lumbosacral brucellosis treated by transforaminal decompression, debridement, interbody fusion, and posterior instrumentation were enrolled. Medical records, imaging studies, laboratory data were collected and summarized. Surgical outcomes were evaluated based on visual analogue scale (VAS), Oswestry Disability Index (ODI) and Japanese Orthopaedic Association (JOA) scale. The changes in C-reactive protein (CRP) levels, erythrocyte sedimentation rate (ESR), clinical symptoms and complications were investigated. Graft fusion was evaluated using Bridwell grading criteria. The mean follow-up period was 24.9 ± 8.2 months. Back pain and radiating leg pain was relieved significantly in all patients after operation. No implant failures were observed in any patients. Wound infection was observed in two patients and sinus formation was observed in one patient. Solid bony fusion was achieved in 30 patients and the fusion rate was 93.8%. The levels of ESR and CRP were returned to normal by the end of three months' follow-up. VAS and ODI scores were significantly improved (P brucellosis.

  20. Water isotopic ratios from a continuously melted ice core sample

    Directory of Open Access Journals (Sweden)

    V. Gkinis

    2011-11-01

    Full Text Available A new technique for on-line high resolution isotopic analysis of liquid water, tailored for ice core studies is presented. We built an interface between a Wavelength Scanned Cavity Ring Down Spectrometer (WS-CRDS purchased from Picarro Inc. and a Continuous Flow Analysis (CFA system. The system offers the possibility to perform simultaneuous water isotopic analysis of δ18O and δD on a continuous stream of liquid water as generated from a continuously melted ice rod. Injection of sub μl amounts of liquid water is achieved by pumping sample through a fused silica capillary and instantaneously vaporizing it with 100% efficiency in a~home made oven at a temperature of 170 °C. A calibration procedure allows for proper reporting of the data on the VSMOW–SLAP scale. We apply the necessary corrections based on the assessed performance of the system regarding instrumental drifts and dependance on the water concentration in the optical cavity. The melt rates are monitored in order to assign a depth scale to the measured isotopic profiles. Application of spectral methods yields the combined uncertainty of the system at below 0.1‰ and 0.5‰ for δ18O and δD, respectively. This performance is comparable to that achieved with mass spectrometry. Dispersion of the sample in the transfer lines limits the temporal resolution of the technique. In this work we investigate and assess these dispersion effects. By using an optimal filtering method we show how the measured profiles can be corrected for the smoothing effects resulting from the sample dispersion. Considering the significant advantages the technique offers, i.e. simultaneuous measurement of δ18O and δD, potentially in combination with chemical components that are traditionally measured on CFA systems, notable reduction on analysis time and power consumption, we consider it as an alternative to traditional isotope ratio mass spectrometry with the possibility to

  1. UMTRA Project water sampling and analysis plan, Salt Lake City, Utah. Revision 1

    International Nuclear Information System (INIS)

    1995-06-01

    This water sampling and analysis plan describes planned, routine ground water sampling activities at the US Department of Energy Uranium Mill Tailings Remedial Action Project site in Salt Lake City, Utah. This plan identifies and justifies sampling locations, analytical parameters, detection limits, and sampling frequencies for routine monitoring of ground water, sediments, and surface waters at monitoring stations on the site

  2. Characterization and single-stage denitrification anaerobic digestion of spent stream from the hydrolysis-fermentation-combustion process

    Science.gov (United States)

    Singh, Ramnik

    The demand for ethanol as an oxygenate and octane booster in automobile fuel is growing. A number of processes are being investigated for conversion of biomass to ethanol. The Hydrolysis-Fermentation-Combustion (HFC) process for fuel ethanol production developed at the University of California Forest Products Laboratory, Richmond, California is at the stage of technology transfer following over two decades of research and development. This study addresses the technology to be used in treatment of spent streams to be discharged from this process. The treatment design combines a single stage denitrification and anaerobic digestion (SSDAD) for the biological treatment of a representative stream from this process. A typical spent stream contained a wide range of soluble organic materials including: unfermented sugars, components of the feedstocks solubilized in the hydrolysis, acid degradation products of carbohydrates, cleavage products of lignin, water-soluble extractives and phenolics, terpenes and other unfermented organic material, and nitrate ion from the nitric acid used as a catalyst in the hydrolysis reaction. Three sets of experiments were conducted in laboratory scale anaerobic digesters. Commonly available anaerobic sludge from local sewage treatment plants was used as a starter seed and was successfully acclimated to the high nitrate substrate leading to enrichment of denitrifiers. Necessary nutrients and trace elements were identified and supplied to satisfy the obligatory requirements of different groups of bacterial groups present. A major finding was the unique role of ammonium hydroxide in controlling pH leading to steady-state operation of the digester. At steady state operation the reduction in COD was 65%, the nitrate reduction was 88% and the nitrite reduction was 100%. Nitrate was reduced to safe nitrogen gas without buildup of any intermediate products. Organic material was converted to useful methane gas and carbon dioxide. The SSDAD system was

  3. Multielement neutron activation analysis of underground water samples

    International Nuclear Information System (INIS)

    Kusaka, Yuzuru; Tsuji, Haruo; Fujimoto, Yuzo; Ishida, Keiko; Mamuro, Tetsuo.

    1980-01-01

    An instrumental neutron activation analysis by gamma-ray spectrometry with high resolution and large volume Ge (Li) detectors followed by data processing with an electronic computer was applied to the multielemental analysis to elucidate the chemical qualities of the underground water which has been widely used in the sake brewing industries in Mikage, Uozaki and Nishinomiya districts, called as miyamizu. The evaporated residues of the water samples were subjected to the neutron irradiations in reactor for 1 min at a thermal flux of 1.5 x 10 12 n.cm -2 .sec -1 and for 30 hrs at a thermal flux of 9.3 x 10 11 n.cm -2 .sec -1 or for 5 hrs at a thermal flux of 3.9 x 10 12 n.cm -2 .sec -1 . Thus, 11 elements in the former short irradiation and 38 elements in the latter two kinds of long irradiation can be analyzed. Conventional chemical analysis including atomic absorption method and others are also applied on the same samples, and putting the all results together, some considerations concerning the geochemical meaning of the analytical values are made. (author)

  4. A simulation study on performance evaluation of single-stage LiBr–H2O vapor absorption heat pump for chip cooling

    Directory of Open Access Journals (Sweden)

    Manu S.

    2016-12-01

    Full Text Available The growth of Lithium Bromide–Water (LiBr–H2O absorption based heat pump is encouraged for the necessity of extracting high heat from the electronic chips. This paper presents a simulation study of single-stage LiBr–H2O vapor absorption heat pump for chip cooling. In this study, a detailed thermodynamic analysis of the single-stage LiBr–H2O vapor absorption heat pump for chip cooling in the nonexistence of solution heat exchanger was performed and a user-friendly graphical user interface (GUI package including visual components was developed by using MATlab (2008b. The influence of chip temperature on COP (Coefficient of Performance, flow rates and conductance was examined by using the developed package. The model is validated by using the values available in the literature and indicates that there is a greater reduction in the absorber load. The influence of chip temperature on the performance and thermal loads of individual components was studied and it was concluded that, COP increases from 0.7145 to 0.8421 with an increase in chip temperature.

  5. Evaluation of single-stage adjustable strabismus surgery under conscious sedation

    Directory of Open Access Journals (Sweden)

    Sharma Pradeep

    2009-01-01

    Full Text Available Purpose: To evaluate the feasibility and stability of ocular alignment after single-stage adjustable strabismus surgery (SSASS performed under topical anesthesia. Materials and Methods: Forty-five patients of concomitant exodeviations were randomized into three groups of 15 cases each and were operated with three different techniques: Group I - conventional surgery, Group II - two-stage adjustable suture technique with suture adjustment performed 6h postoperatively and Group III- SSASS under topical anesthesia and intravenous conscious sedation with midazolam and fentanyl. Intraoperative suture adjustment was done by giving a cross target to the patient on the ceiling at the end of the procedure. Surgical results were compared among the three groups at three months follow-up. Intraoperative hemodynamic parameters and patients′ experience of the surgery (by questionnaire were also compared. Results: Mean preoperative deviation for distance in Groups I, II, III was -41.67 prism diopter (pd ±9.0, -38.93 pd ±11.05 and -41.87 pd ±8.91 ( P =0.6 respectively. At three months, mean correction achieved for distance was +31.87 pd ±11.71, +35.47 pd ±10.86 and +42.80 pd ±10.71 respectively which was significantly different between Group III and Group I ( P =0.03. Intraoperatively all hemodynamic parameters remained stable and comparable ( P =0. 5 in all groups. Intraoperative pain ( P < 0.001 and time taken for surgery ( P < 0.001 was more in the SSASS group. Amount of exodrift was 10-12 pd, comparable in all three groups ( P = 0.5. Conclusions: SSASS, performed under topical anesthesia, is safe and has better outcomes than conventional recession-resection surgery for concomitant exodeviation. An overcorrection of about 10-12 pd is recommended to check the exodrift and achieve stable alignment.

  6. Metoidioplasty as a single stage sex reassignment surgery in female transsexuals: Belgrade experience.

    Science.gov (United States)

    Djordjevic, Miroslav L; Stanojevic, Dusan; Bizic, Marta; Kojovic, Vladimir; Majstorovic, Marko; Vujovic, Svetlana; Milosevic, Alexandar; Korac, Gradimir; Perovic, Sava V

    2009-05-01

    Metoidioplasty represents one of the variants of phalloplasty in female transsexuals. Its main characteristic is that it is a one-stage procedure. It involves lengthening and straightening of hypertrophied clitoris to create a neophallus, urethral lengthening to enable voiding while standing, and scrotal reconstruction with insertion of testicle prostheses. Our aim is to describe our technique and highlight its advantages. Between September 2002 and April 2007, 82 female transsexuals, aged 18-54 years (mean age 31) underwent one-stage metoidioplasty. Clitoris is lengthened and straightened by division of clitoral ligaments and short urethral plate. Urethroplasty is done with combined buccal mucosa graft and genital skin flaps. Scrotum is created from labia majora in which two testicle prostheses are inserted. Simultaneously, female genitalia are removed. Patients' personal satisfaction about sensitivity and length of neophallus, possibility to void in standing position, real length of reconstructed urethra as well as complication rate comparing to other published data. The median follow-up was 32 months (range 14-69). The mean neophallic length was 5.7 cm (range 4-10). Voiding in standing position was reported in all patients, while dribbling and spraying were noticed in 23 cases and solved spontaneously. There were two urethral strictures and seven fistulas that required secondary minor revision. All patients reported preserved sensation and normal postoperative erection. Testicle prostheses rejection was not observed in any of the patients. Metoidioplasty is a single-stage and time-saving procedure. It could be an alternative to total phalloplasty in female transsexuals who do not wish to have sexual intercourse. Also, it represents a first step in cases where additional augmentation phalloplasty is required.

  7. An operation protocol for facilitating start-up of single-stage autotrophic nitrogen removing reactors based on process stoichiometry

    DEFF Research Database (Denmark)

    Mutlu, A. Gizem; Vangsgaard, Anna Katrine; Sin, Gürkan

    2012-01-01

    Start-up and operation of single-stage nitritation/anammox reactor employing complete autotrophic nitrogen can be difficult. Keeping the performance criteria and monitoring the microbial community composition may not be easy or fast enough to take action on time. In this study, a control strategy...

  8. Low voltage ride-through capability control for single-stage inverter-based grid-connected photovoltaic power plant

    DEFF Research Database (Denmark)

    Al-Shetwi, Ali Q.; Sujod, Muhamad Zahim; Blaabjerg, Frede

    2018-01-01

    The low voltage ride-through (LVRT) capability is one of the challenges faced by the integration of large-scale photovoltaic (PV) power stations into electrical grid which has not been fully investigated. Therefore, this paper presents a comprehensive control strategy of single-stage PV power pla...

  9. Revision Anterior Cruciate Ligament Reconstruction: Results of a Single-stage Approach Using Allograft Dowel Bone Grafting for Femoral Defects.

    Science.gov (United States)

    Werner, Brian C; Gilmore, Carl J; Hamann, Joshua C; Gaskin, Cree M; Carroll, John J; Hart, Joseph M; Miller, Mark D

    2016-08-01

    The purpose of this study was to present results of single-stage revision anterior cruciate ligament (ACL) reconstruction using an allograft bone dowel for isolated femoral bony deficiency. Sixteen patients underwent single-stage revision ACL reconstruction using an allograft bone dowel for isolated femoral bony deficiency between 2007 and 2012. Twelve patients (75%) completed study visits, which included CT scans as well as completion of validated outcomes measures. The average KT-1000 side-to-side difference was 1.0 mm ± 2.9 mm. The average International Knee Documentation Committee score was 70.2 ± 17.8, the Tegner score was 4.8 ± 2.8, and the visual analog scale pain score was 2.8 ± 2.4. An analysis of CT scans showed that all 12 dowels had excellent (>75%) incorporation. A single-stage approach for revision ACL reconstruction using allograft dowels for isolated femoral bony deficiency yields objective and subjective outcomes comparable to those reported in the literature for two-stage and other single-stage techniques, with good incorporation of the dowels. Retrospective case series, level IV.

  10. Two-stage IMZ implants and ITI implants inserted in a single-stage procedure : A prospective comparative study

    NARCIS (Netherlands)

    Heydenrijk, Kees; Raghoebar, Gerry M.; Meijer, Henny J.A.; Reijden, Willy A. van der; Winkelhoff, Arie Jan van; Stegenga, Boudewijn

    2002-01-01

    The aim of this study was to evaluate the feasibility of using a two-stage implant system in a single-stage procedure and to study the impact of the microgap at crestal level and to monitor the microflora in the peri-implant area. Forty edentulous patients (Cawood & Howell class V–VI) participated

  11. Two-stage IMZ implants and ITI implants inserted in a single-stage procedure - A prospective comparative study

    NARCIS (Netherlands)

    Heydenrijk, K; Raghoebar, GM; Meijer, HJA; van der Reijden, WA; van Winkelhoff, AJ; Stegenga, B

    The aim of this study was to evaluate the feasibility of using a two-stage implant system in a single-stage procedure and to study the impact of the microgap at crestal level and to monitor the microflora in the peri-implant area. Forty edentulous patients (Cawood & Howell class V-VI) participated

  12. Liquid Water from First Principles: Validation of Different Sampling Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Mundy, C J; Kuo, W; Siepmann, J; McGrath, M J; Vondevondele, J; Sprik, M; Hutter, J; Parrinello, M; Mohamed, F; Krack, M; Chen, B; Klein, M

    2004-05-20

    A series of first principles molecular dynamics and Monte Carlo simulations were carried out for liquid water to assess the validity and reproducibility of different sampling approaches. These simulations include Car-Parrinello molecular dynamics simulations using the program CPMD with different values of the fictitious electron mass in the microcanonical and canonical ensembles, Born-Oppenheimer molecular dynamics using the programs CPMD and CP2K in the microcanonical ensemble, and Metropolis Monte Carlo using CP2K in the canonical ensemble. With the exception of one simulation for 128 water molecules, all other simulations were carried out for systems consisting of 64 molecules. It is found that the structural and thermodynamic properties of these simulations are in excellent agreement with each other as long as adiabatic sampling is maintained in the Car-Parrinello molecular dynamics simulations either by choosing a sufficiently small fictitious mass in the microcanonical ensemble or by Nos{acute e}-Hoover thermostats in the canonical ensemble. Using the Becke-Lee-Yang-Parr exchange and correlation energy functionals and norm-conserving Troullier-Martins or Goedecker-Teter-Hutter pseudopotentials, simulations at a fixed density of 1.0 g/cm{sup 3} and a temperature close to 315 K yield a height of the first peak in the oxygen-oxygen radial distribution function of about 3.0, a classical constant-volume heat capacity of about 70 J K{sup -1} mol{sup -1}, and a self-diffusion constant of about 0.1 Angstroms{sup 2}/ps.

  13. Determination of trihalomethanes in water samples: A review

    Energy Technology Data Exchange (ETDEWEB)

    Perez Pavon, Jose Luis [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias Quimicas, Universidad de Salamanca, 37008 Salamanca (Spain)], E-mail: jlpp@usal.es; Herrero Martin, Sara; Garcia Pinto, Carmelo; Moreno Cordero, Bernardo [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias Quimicas, Universidad de Salamanca, 37008 Salamanca (Spain)

    2008-11-23

    This article reviews the most recent literature addressing the analytical methods applied for trihalomethanes (THMs) determination in water samples. This analysis is usually performed with gas chromatography (GC) combined with a preconcentration step. The detectors most widely used in this type of analyses are mass spectrometers (MS) and electron capture detectors (ECD). Here, we review the analytical characteristics, the time required for analysis, and the simplicity of the optimised methods. The main difference between these methods lies in the sample pretreatment step; therefore, special emphasis is placed on this aspect. The techniques covered are direct aqueous injection (DAI), liquid-liquid extraction (LLE), headspace (HS), and membrane-based techniques. We also review the main chromatographic columns employed and consider novel aspects of chromatographic analysis, such as the use of fast gas chromatography (FGC). Concerning the detection step, besides the common techniques, the use of uncommon detectors such as fluorescence detector, pulsed discharge photoionization detector (PDPID), dry electrolytic conductivity detector (DELCD), atomic emission detector (AED) and inductively coupled plasma-mass spectrometry (ICP-MS) for this type of analysis is described.

  14. Sampling trace organic compounds in water: a comparison of a continuous active sampler to continuous passive and discrete sampling methods

    Science.gov (United States)

    Coes, Alissa L.; Paretti, Nicholas V.; Foreman, William T.; Iverson, Jana L.; Alvarez, David A.

    2014-01-01

    A continuous active sampling method was compared to continuous passive and discrete sampling methods for the sampling of trace organic compounds (TOCs) in water. Results from each method are compared and contrasted in order to provide information for future investigators to use while selecting appropriate sampling methods for their research. The continuous low-level aquatic monitoring (CLAM) sampler (C.I.Agent® Storm-Water Solutions) is a submersible, low flow-rate sampler, that continuously draws water through solid-phase extraction media. CLAM samplers were deployed at two wastewater-dominated stream field sites in conjunction with the deployment of polar organic chemical integrative samplers (POCIS) and the collection of discrete (grab) water samples. All samples were analyzed for a suite of 69 TOCs. The CLAM and POCIS samples represent time-integrated samples that accumulate the TOCs present in the water over the deployment period (19–23 h for CLAM and 29 days for POCIS); the discrete samples represent only the TOCs present in the water at the time and place of sampling. Non-metric multi-dimensional scaling and cluster analysis were used to examine patterns in both TOC detections and relative concentrations between the three sampling methods. A greater number of TOCs were detected in the CLAM samples than in corresponding discrete and POCIS samples, but TOC concentrations in the CLAM samples were significantly lower than in the discrete and (or) POCIS samples. Thirteen TOCs of varying polarity were detected by all of the three methods. TOC detections and concentrations obtained by the three sampling methods, however, are dependent on multiple factors. This study found that stream discharge, constituent loading, and compound type all affected TOC concentrations detected by each method. In addition, TOC detections and concentrations were affected by the reporting limits, bias, recovery, and performance of each method.

  15. Laser based water equilibration method for d18O determination of water samples

    Science.gov (United States)

    Mandic, Magda; Smajgl, Danijela; Stoebener, Nils

    2017-04-01

    Determination of d18O with water equilibration method using mass spectrometers equipped with equilibration unit or Gas Bench is known already for many years. Now, with development of laser spectrometers this extends methods and possibilities to apply different technologies in laboratory but also in the field. The Thermo Scientific™ Delta Ray™ Isotope Ratio Infrared Spectrometer (IRIS) analyzer with the Universal Reference Interface (URI) Connect and Teledyne Cetac ASX-7100 offers high precision and throughput of samples. It employs optical spectroscopy for continuous measurement of isotope ratio values and concentration of carbon dioxide in ambient air, and also for analysis of discrete samples from vials, syringes, bags, or other user-provided sample containers. Test measurements and conformation of precision and accuracy of method determination d18O in water samples were done in Thermo Fisher application laboratory with three lab standards, namely ANST, Ocean II and HBW. All laboratory standards were previously calibrated with international reference material VSMOW2 and SLAP2 to assure accuracy of the isotopic values of the water. With method that we present in this work achieved repeatability and accuracy are 0.16‰ and 0.71‰, respectively, which fulfill requirements of regulatory method for wine and must after equilibration with CO2.

  16. Verification of spectrophotometric method for nitrate analysis in water samples

    Science.gov (United States)

    Kurniawati, Puji; Gusrianti, Reny; Dwisiwi, Bledug Bernanti; Purbaningtias, Tri Esti; Wiyantoko, Bayu

    2017-12-01

    The aim of this research was to verify the spectrophotometric method to analyze nitrate in water samples using APHA 2012 Section 4500 NO3-B method. The verification parameters used were: linearity, method detection limit, level of quantitation, level of linearity, accuracy and precision. Linearity was obtained by using 0 to 50 mg/L nitrate standard solution and the correlation coefficient of standard calibration linear regression equation was 0.9981. The method detection limit (MDL) was defined as 0,1294 mg/L and limit of quantitation (LOQ) was 0,4117 mg/L. The result of a level of linearity (LOL) was 50 mg/L and nitrate concentration 10 to 50 mg/L was linear with a level of confidence was 99%. The accuracy was determined through recovery value was 109.1907%. The precision value was observed using % relative standard deviation (%RSD) from repeatability and its result was 1.0886%. The tested performance criteria showed that the methodology was verified under the laboratory conditions.

  17. Assessment of Sr-90 in water samples: precision and accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Nisti, Marcelo B.; Saueia, Cátia H.R.; Castilho, Bruna; Mazzilli, Barbara P., E-mail: mbnisti@ipen.br, E-mail: chsaueia@ipen.br, E-mail: bcastilho@ipen.br, E-mail: mazzilli@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    The study of artificial radionuclides dispersion into the environment is very important to control the nuclear waste discharges, nuclear accidents and nuclear weapons testing. The accidents in Fukushima Daiichi Nuclear Power Plant and Chernobyl Nuclear Power Plant, released several radionuclides in the environment by aerial deposition and liquid discharge, with various level of radioactivity. The {sup 90}Sr was one of the elements released into the environment. The {sup 90}Sr is produced by nuclear fission with a physical half-life of 28.79 years with decay energy of 0.546 MeV. The aims of this study are to evaluate the precision and accuracy of three methodologies for the determination of {sup 90}Sr in water samples: Cerenkov, LSC direct method and with radiochemical separation. The performance of the methodologies was evaluated by using two scintillation counters (Quantulus and Hidex). The parameters Minimum Detectable Activity (MDA) and Figure Of Merit (FOM) were determined for each method, the precision and accuracy were checked using {sup 90}Sr standard solutions. (author)

  18. Methods to maximise recovery of environmental DNA from water samples.

    Directory of Open Access Journals (Sweden)

    Rheyda Hinlo

    Full Text Available The environmental DNA (eDNA method is a detection technique that is rapidly gaining credibility as a sensitive tool useful in the surveillance and monitoring of invasive and threatened species. Because eDNA analysis often deals with small quantities of short and degraded DNA fragments, methods that maximize eDNA recovery are required to increase detectability. In this study, we performed experiments at different stages of the eDNA analysis to show which combinations of methods give the best recovery rate for eDNA. Using Oriental weatherloach (Misgurnus anguillicaudatus as a study species, we show that various combinations of DNA capture, preservation and extraction methods can significantly affect DNA yield. Filtration using cellulose nitrate filter paper preserved in ethanol or stored in a -20°C freezer and extracted with the Qiagen DNeasy kit outperformed other combinations in terms of cost and efficiency of DNA recovery. Our results support the recommendation to filter water samples within 24hours but if this is not possible, our results suggest that refrigeration may be a better option than freezing for short-term storage (i.e., 3-5 days. This information is useful in designing eDNA detection of low-density invasive or threatened species, where small variations in DNA recovery can signify the difference between detection success or failure.

  19. Effects of Stator Shroud Injection on the Aerodynamic Performance of a Single-Stage Transonic Axial Compressor

    International Nuclear Information System (INIS)

    Dinh, Cong-Truong; Ma, Sang-Bum; Kim, Kwang Yong

    2017-01-01

    In this study, stator shroud injection in a single-stage transonic axial compressor is proposed. A parametric study of the effect of stator shroud injection on aerodynamic performances was conducted using the three-dimensional Reynolds-averaged Navier-Stokes equations. The curvature, length, width, and circumferential angle of the stator shroud injector and the air injection mass flow rate were selected as the test parameters. The results of the parametric study show that the aerodynamic performances of the single-stage transonic axial compressor were improved by stator shroud injection. The aerodynamic performances were the most sensitive to the injection mass flow rate. Further, the total pressure ratio and adiabatic efficiency were the maximum when the ratio of circumferential angle was 10%.

  20. Effects of Stator Shroud Injection on the Aerodynamic Performance of a Single-Stage Transonic Axial Compressor

    Energy Technology Data Exchange (ETDEWEB)

    Dinh, Cong-Truong; Ma, Sang-Bum; Kim, Kwang Yong [Inha Univ., Incheon (Korea, Republic of)

    2017-01-15

    In this study, stator shroud injection in a single-stage transonic axial compressor is proposed. A parametric study of the effect of stator shroud injection on aerodynamic performances was conducted using the three-dimensional Reynolds-averaged Navier-Stokes equations. The curvature, length, width, and circumferential angle of the stator shroud injector and the air injection mass flow rate were selected as the test parameters. The results of the parametric study show that the aerodynamic performances of the single-stage transonic axial compressor were improved by stator shroud injection. The aerodynamic performances were the most sensitive to the injection mass flow rate. Further, the total pressure ratio and adiabatic efficiency were the maximum when the ratio of circumferential angle was 10%.

  1. Modeling of DNA single stage splicing language via Yusof-Goode approach: One string with two rules

    Science.gov (United States)

    Lim, Wen Li; Yusof, Yuhani; Mudaber, Mohammad Hassan

    2015-02-01

    Splicing system plays a pivotal role in attempts to recombine sets of double-stranded DNA molecules when acted by restriction enzymes and ligase. Traditional method of finding the result of DNA recombination through experiment is both time and money consuming. Hence, finding the number of patterns of DNA single stage splicing language through formalism of splicing system is a way to optimize the searching process. From the biological perspective, it predicts the number of types of molecules that will exist in the system under existence of restriction enzymes and ligase. In this paper, some theorems, corollaries and examples that lead to the predictions of single stage splicing languages involving one pattern string and two rules are presented via Yusof-Goode approach.

  2. Comparison of single-stage and temperature-phased two-stage anaerobic digestion of oily food waste

    International Nuclear Information System (INIS)

    Wu, Li-Jie; Kobayashi, Takuro; Li, Yu-You; Xu, Kai-Qin

    2015-01-01

    Highlights: • A single-stage and two two-stage anaerobic systems were synchronously operated. • Similar methane production 0.44 L/g VS added from oily food waste was achieved. • The first stage of the two-stage process became inefficient due to serious pH drop. • Recycle favored the hythan production in the two-stage digestion. • The conversion of unsaturated fatty acids was enhanced by recycle introduction. - Abstract: Anaerobic digestion is an effective technology to recover energy from oily food waste. A single-stage system and temperature-phased two-stage systems with and without recycle for anaerobic digestion of oily food waste were constructed to compare the operation performances. The synchronous operation indicated the similar ability to produce methane in the three systems, with a methane yield of 0.44 L/g VS added . The pH drop to less than 4.0 in the first stage of two-stage system without recycle resulted in poor hydrolysis, and methane or hydrogen was not produced in this stage. Alkalinity supplement from the second stage of two-stage system with recycle improved pH in the first stage to 5.4. Consequently, 35.3% of the particulate COD in the influent was reduced in the first stage of two-stage system with recycle according to a COD mass balance, and hydrogen was produced with a percentage of 31.7%, accordingly. Similar solids and organic matter were removed in the single-stage system and two-stage system without recycle. More lipid degradation and the conversion of long-chain fatty acids were achieved in the single-stage system. Recycling was proved to be effective in promoting the conversion of unsaturated long-chain fatty acids into saturated fatty acids in the two-stage system.

  3. Single stage incubators and Hypercapnia during incubation affect the vascularization of the chorioallantoic membrane in broiler embryos.

    Science.gov (United States)

    Fernandes, J I M; Bortoluzzi, C; Schmidt, J M; Scapini, L B; Santos, T C; Murakami, A E

    2017-01-01

    Incubation management can have direct effects on neonate health and consequently affect post-hatching development. The effects of incubation in multiple and single stage incubators with different concentrations of CO 2 were evaluated in terms of the vessel density in the chorioallantoic membrane, hatching, heart morphology, and body development of the neonate up to the tenth day. A total of 2,520 fertile eggs were used and distributed in a completely randomized design with 4 levels of CO 2 in 4 single-stage incubators (4,000; 6,000; 8,000; and 10,000 ppm) and a control treatment based on multiple-stage incubation, totaling 5 treatments. The levels of CO 2 were used during the first 10 d of the incubation period, and after this period, all eggs were submitted to the same level of CO 2 (4,000 ppm). Eggs that were incubated in multiple-stage incubators presented a lower percentage of vessels in the chorioallantoic membrane, lower yolk absorption by the embryo, wall depth of the right ventricle, and greater humidity losses in the eggs when compared to eggs in the single-stage incubators. The eggs submitted to hypercapnia, between 5,000 and 6,000 ppm of CO 2 , had a higher percentage of vessels in the chorioallantoic membrane; the embryos originating from these eggs had higher weight, with higher relative weight of the liver. However, the same levels reduced the yolk absorption. Single-stage incubation with moderate levels of hypercapnia is an efficient tool to be adopted by the hatcheries when attempting to improve chick quality. © 2016 Poultry Science Association Inc.

  4. Performance analysis of a single stage four bed metal hydride cooling system, part A: Influence of mass recovery

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Kevin; Prakash Maiya, M.; Srinivasa Murthy, S. [Refrigeration and Air-conditioning Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Madras, 600036, Chennai (India)

    2003-01-01

    The concept of mass recovery in metal hydride systems is studied with a single stage multi-bed cooling system as example. Mass recovery results in variation of bed temperatures due to removal or addition of heat of desorption or absorption respectively. Coefficient of performance and cold output increase while required heat input decreases for the mass recovery cycle. Thus mass recovery between hydride reactors is found to improve system performance compared to that of a basic system. (authors)

  5. bacteriological analysis of well water samples in sagamu.

    African Journals Online (AJOL)

    Dr Oboro VO

    diseases that affect human and animals cannot be underestimated. This is the most important concern about the quality of water. Guideline for bacteriological water ..... serious problem which calls for vigilance on the part of the authorities as it signals possible future outbreak of water borne diseases. Such disease outbreak ...

  6. Bacteriological analysis of well water samples in Sagamu | Idowu ...

    African Journals Online (AJOL)

    Majority of the population in semi-urban and urban areas of Nigeria depend on wells as their source of water supply. Due to increasing cases of water-borne diseases in recent times, this study was carried out to examine the microbial quality of well water in Sagamu, Nigeria as a way of safeguarding public health against ...

  7. How can recovery be enhanced after single-stage laparoscopic management of CBD stones? Endoscopic treatment versus laparoscopic surgery.

    Science.gov (United States)

    Chapuis-Roux, Emilie; Pellissier, Laurent; Browet, Francois; Berthou, Jean Charles; Hakim, Sami; Brazier, Franck; Cosse, Cyril; Delcenserie, Richard; Regimbeau, Jean Marc

    2017-07-01

    Single-stage management of CBD stones comprises simultaneous common bile duct (CBD) clearance and cholecystectomy. The CBD can be cleared by using endoscopic treatment (ET) or laparoscopic surgery (LS) alone. To determine the most rapid recovery after the single-stage laparoscopic management of CBD stones. Patients with CBD stones treated at either of two centers (one performing ET only and one performing LS only for single-stage treatment) were included. The primary endpoint was "the textbook outcome". The feasibility rate was 74% for ET and 100% for LS (p≤0.001). The proportion of cases with the textbook outcome was higher in the ET group than in the LS-only group (73% vs. 10%; pCBD clearance rate was similar in the ET and LS-only groups (100% vs. 96.6%, respectively; p=0.17). The overall morbidity rate was lower in the ET group than in the LS-only group (23% vs. 29%, p=0.05). Both ET and LS are feasible, safe and effective for clearance of the CBD. ET was better than LS in terms of a less frequent requirement for drainage and a shorter length of hospital stay. LS was associated with a shorter operating time. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  8. Real-time analysis of water movement in plant sample

    Energy Technology Data Exchange (ETDEWEB)

    Yokota, Harumi; Furukawa, Jun; Tanoi, Keitaro [Graduate School, Tokyo Univ. (Japan)

    2000-07-01

    To know the effect of drought stress on two cultivars of cowpea, drought tolerant (DT) and drought sensitive (DS), and to estimate vanadium treatment on plant activity, we performed real time{sup 18}F labeled water uptake measurement by PETIS. Fluoride-18 was produced by bombarding a cubic ice target with 50 MeV protons using TIARA AVF cyclotron. Then {sup 18}F labeled water was applied to investigate water movement in a cowpea plant. Real time water uptake manner could be monitored by PETIS. After the analysis by PETIS, we also measured the distribution of {sup 18}F in a whole plant by BAS. When a cowpea plant was treated with drought stress, there was a difference in water uptake manner between DT and DS cultivar. When a cowpea plant was treated with V for 20 hours before the water uptake experiment, the total amount of {sup 18}F labeled water absorption was found to be drastically decreased. (author)

  9. Development of analytical techniques for water and environmental samples (2)

    Energy Technology Data Exchange (ETDEWEB)

    Eum, Chul Hun; Jeon, Chi Wan; Jung, Kang Sup; Song, Kyung Sun; Kim, Sang Yeon [Korea Institute of Geology Mining and Materials, Taejon (Korea)

    1998-12-01

    The purpose of this study is to develop new analytical methods with good detection limit for toxic inorganic and organic compounds. The analyses of CN, organic acids, particulate materials in environmental samples have been done using several methods such as Ion Chromatography, SPE, SPME, GC/MS, GC/FID, SPLITT (split-flow thin cell fractionation) during the second year of this project. Advantage and disadvantage of several distillation method (by KS, JIS, EPA) for CN analysis in wastewater were investigated. As the results, we proposed new distillation apparatus for CN analysis, which was proved to be simpler, faster and to get better recovery than conventional apparatus. And ion chromatograph/pulsed amperometric detector (IC/PAD) system instead of colorimetry for CN detection was setup to solve matrix interference. And SPE(solid phase extraction) and SPME (solid phase micro extraction) as liquid-solid extraction technique were applied to the analysis of phenols in wastewater. Optimum experimental conditions and factors influencing analytical results were determined. From these results, It could be concluded that C{sub 18} cartridge and polystyrene-divinylbenzene disk in SPE method, polyacrylate fiber in SPME were proper solid phase adsorbent for phenol. Optimum conditions to analyze phenol derivatives simultaneously were established. Also, Continuous SPLITT (Split-flow thin cell) Fractionation (CSF) is a new preparative separation technique that is useful for fractionation of particulate and macromolecular materials. CSF is carried out in a thin ribbon-like channel equipped with two splitters at both inlet and outlet of the channel. In this work, we set up a new CSF system, and tested using polystyrene latex standard particles. And then we fractionated particles contained in air and underground water based on their sedimentation coefficients using CSF. (author). 27 refs., 13 tabs., 31 figs.

  10. Single-stage revision from gastric band to gastric bypass or sleeve gastrectomy: 6- and 12-month outcomes.

    Science.gov (United States)

    Yeung, Louise; Durkan, Brandice; Barrett, Allison; Kraft, Cary; Vu, Kim; Phillips, Edward; Cunneen, Scott; Burch, Miguel

    2016-06-01

    Laparoscopic adjustable gastric banding (LAGB) is increasingly requiring revisional surgery for complications and failures. Removal of the band and conversion to either laparoscopic Roux-en-y gastric bypass (LRYGB) or laparoscopic sleeve gastrectomy (LSG) is feasible as a single-stage procedure. The objective of this study is to compare the safety and efficacy of single-stage revision from LAGB to either LRYGB or LSG at 6 and 12 months postoperatively. Retrospective analysis was performed on patients undergoing single-stage revision between 2009 and 2014 at a single academic medical center. Patients were reassessed for weight loss and complications at 6 and 12 months postoperatively. Thirty-two patients underwent single-stage revision to LRYGB, and 72 to LSG. Preoperative BMIs were similar between the two groups (p = 0.27). Median length of stay for LRYGB was 3 days versus 2 for LSG (p = 0.14). Four patients in the LRYGB group required reoperation within 30 days, and two patients in the LSG group required reoperation within 30 days (p = 0.15). There was no difference in ER visits (p = 0.24) or readmission rates (p = 0.80) within 30 days of operation. Six delayed complications were seen in the LSG group with three requiring intervention. At 6 months postoperatively, percent excess weight loss (%EWL) was 50.20 for LRYGB and 30.64 for LSG (p = 0.056). At 12 months, %EWL was 51.19 for LRYGB and 34.89 for LSG (p = 0.31). There was no difference in diabetes or hypertension medication reduction at 12 months between LRYGB and LSG (p > 0.07). Single-stage revision from LAGB to LRYGB or LSG is technically feasible, but not without complications. The complications in the bypass group were more severe. There was no difference in readmission or reoperation rates, weight loss or comorbidity reduction. Revision to LRYGB trended toward higher rate and greater severity of complications with equivalent weight loss and comorbidity reduction.

  11. Representation of solid and nutrient concentrations in irrigation water from tailwater recovery systems by surface water grab samples

    Science.gov (United States)

    Tailwater recovery (TWR) systems are being implemented on agricultural landscapes to create an additional source of irrigation water. Existing studies have sampled TWR systems using grab samples; however, the applicability of solids and nutrient concentrations in these samples to water being irrigat...

  12. Multi-analysis determination of tropane alkaloids in cereals and solanaceaes seeds by liquid chromatography coupled to single stage Exactive-Orbitrap.

    Science.gov (United States)

    Marín-Sáez, Jesús; Romero-González, Roberto; Garrido Frenich, Antonia

    2017-10-06

    Tropane alkaloids are a wide group of substances that comprises more than 200 compounds occurring especially in the Solanaceae family. The main aim of this study is the development of a method for the analysis of the principal tropane alkaloids as atropine, scopolamine, anisodamine, tropane, tropine, littorine, homatropine, apoatropine, aposcopolamine, scopoline, tropinone, physoperuvine, pseudotropine and cuscohygrine in cereals and related matrices. For that, a simple solid-liquid extraction was optimized and a liquid chromatographic method coupled to a single stage Exactive-Orbitrap was developed. The method was validated obtaining recoveries in the range of 60-109% (except for some compounds in soy), precision values (expressed as relative standard deviation) lower than 20% and detection and quantification limits equal to or lower than 2 and 3μg/kg respectively. Finally, the method was applied to the analysis of different types of samples as buckwheat, linseed, soy and millet, obtaining positives for anisodamine, scopolamine, atropine, littorine and tropinone in a millet flour sample above the quantification limits, whereas atropine and scopolamine were detected in a buckwheat sample, below the quantification limit. Contaminated samples with Solanaceaes seeds (Datura Stramonium and Brugmansia Arborea) were also analysed, detecting concentrations up to 693μg/kg (scopolamine) for contaminated samples with Brugmansia seeds and 1847μg/kg (atropine) when samples were contaminated with Stramonium seeds. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Titrimetric determination of arsenic concentration in water samples ...

    African Journals Online (AJOL)

    This research is aimed at titrimetric determination of Arsenic concentration in samples collected from boreholes and irrigation channels of Hadejia Emirate council, Jigawa State, Nigeria. Twenty three samples were randomly collected using standard techniques. The pH of the samples was determined immediately at the ...

  14. Tritium concentrations in environmental water and food samples collected around the vicinity of the PNPP-1

    International Nuclear Information System (INIS)

    Garcia, T.Y.; Enriquez, S.O.; Duran, E.B.

    1986-01-01

    The natural radioactivity levels of tritium in environmental samples collected around the vicinity and more distant environment of the first Philippine Nuclear Power Plant (PNPP-1) in Bataan were assessed. The samples analyzed consisted of water samples such as seawater, freshwater, drinking water, groundwater and rainwater; and food samples such as cereals, vegetables, fruits; meat, milk fish and crustaceans. Tritium concentrations in water samples were determined by distillation and liquid scintillation counting techniques. The food samples were analyzed for tissue-free water tritium by the freezing-drying method followed by liquid scintillation counting techniques. (Auth.) 13 refs

  15. Soluble and insoluble pollutants in fog and rime water samples

    Czech Academy of Sciences Publication Activity Database

    Fišák, Jaroslav; Stoyanova, V.; Chaloupecký, Pavel; Řezáčová, Daniela; Tsacheva, Ts.; Kupenova, T.; Marinov, M.

    2009-01-01

    Roč. 4, Sp. Iss. 2 (2009), S123-S130 ISSN 1801-5395 R&D Projects: GA ČR GA205/09/1918; GA AV ČR 1QS200420562 Institutional research plan: CEZ:AV0Z30420517 Keywords : fog water * rime water * pollutant concentration Subject RIV: DG - Athmosphere Sciences, Meteorology

  16. Evaluation Of Sachet Water Samples In Owerri Metropolis | Nwosu ...

    African Journals Online (AJOL)

    Other surveys revealed that 12 brands had fake manufactures' address, 2 brands had NAFDAC registration number while 3 brands had genuine manufacturers' address on them. It was discovered that the producers packaged the water from their water source without any form of treatment or analysis on it. Key words: ...

  17. Physico-chemical characteristics of water sample from Aiba Stream ...

    African Journals Online (AJOL)

    Aiba stream was an outlet of Aiba reservoir (Figure 1). The stream drains through Kuti road, Oweyo and ... solar distillation and this has also removed the settling solids that the water contain since temperature of water .... dissolution of salts deposits, domestic and industrial sewage discharge of effluent etc. The results of the ...

  18. chemical and microbiological assessment of surface water samples ...

    African Journals Online (AJOL)

    PROF EKWUEME

    are to assess, ascertain and evaluate the level, degree and type of pollution that characterize the surface water resources of Enugu area of ... implications for economic development since people relies heavily on it for various uses such as ... surface water bodies are prone to impacts from anthropogenic activities apart from ...

  19. Physico-chemical Properties of Water Samples from Manipur River ...

    African Journals Online (AJOL)

    Michael Horsfall

    the rivers indicating degradation of water quality during rainy season than summer. Values of DO was below the ... river system were within the WHO limits for drinking water and, therefore, may be suitable for domestic purposes. @ JASEM. ... help of a mercury thermometer, transparency with secchi disc, conductivity with ...

  20. Storm Water Sampling Data 11-16-17.

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Robert C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-12-01

    In the California Industrial General Permit (IGP) 2014-0057-DWQ for storm water monitoring, effective July 1, 2015, there are 21 contaminants that have been assigned NAL (Numeric Action Level) values, both annual and instantaneous.

  1. Demonstration of the Gore Module for Passive Ground Water Sampling

    Science.gov (United States)

    2014-06-01

    3). Figure 3. Location of the SBR site on APG, Maryland. APG is located in the headwaters of the Chesapeake Bay and lies on two peninsulas...aqueous solution by the Module (determined in the laboratory), water temperature, and water pressure. The foundation for this model mirrors accepted...the City of Portsmouth. The former AFB occupies approximately 4,365 acres and is bounded on the west and southwest by Great Bay , on the northwest by

  2. Mutagenicity of drinking water sampled from the Yangtze River and Hanshui River (Wuhan section) and correlations with water quality parameters.

    Science.gov (United States)

    Lv, Xuemin; Lu, Yi; Yang, Xiaoming; Dong, Xiaorong; Ma, Kunpeng; Xiao, Sanhua; Wang, Yazhou; Tang, Fei

    2015-03-31

    A total of 54 water samples were collected during three different hydrologic periods (level period, wet period, and dry period) from Plant A and Plant B (a source for Yangtze River and Hanshui River water, respectively), and several water parameters, such as chemical oxygen demand (COD), turbidity, and total organic carbon (TOC), were simultaneously analyzed. The mutagenicity of the water samples was evaluated using the Ames test with Salmonella typhimurium strains TA98 and TA100. According to the results, the organic compounds in the water were largely frame-shift mutagens, as positive results were found for most of the tests using TA98. All of the finished water samples exhibited stronger mutagenicity than the relative raw and distribution water samples, with water samples collected from Plant B presenting stronger mutagenic strength than those from Plant A. The finished water samples from Plant A displayed a seasonal-dependent variation. Water parameters including COD (r = 0.599, P = 0.009), TOC (r = 0.681, P = 0.02), UV254 (r = 0.711, P = 0.001), and total nitrogen (r = 0.570, P = 0.014) exhibited good correlations with mutagenicity (TA98), at 2.0 L/plate, which bolsters the argument of the importance of using mutagenicity as a new parameter to assess the quality of drinking water.

  3. 384 Power plant waste water sampling and analysis plan

    International Nuclear Information System (INIS)

    Hagerty, K.J.; Knotek, H.M.

    1995-01-01

    This document presents the 384 Power House Sampling and Analysis Plan. The Plan describes sampling methods, locations, frequency, analytes, and stream descriptions. The effluent streams from 384, were characterized in 1989, in support of the Stream Specific Report (WHC-EP-0342, Addendum 1)

  4. Single-stage treatment of infected tibial non-unions and osteomyelitis with bone marrow granulocytes precursors protecting bone graft.

    Science.gov (United States)

    Hernigou, Philippe; Dubory, Arnaud; Homma, Yasuhiro; Flouzat Lachaniette, Charles Henri; Chevallier, Nathalie; Rouard, Helene

    2017-11-13

    Infected non-unions present a clinical challenge, especially with risk of recurrent infection. Bone marrow contains granulocyte precursors identified in vitro as colony forming units-granulocyte macrophage (CFU-GM) have a prophylactic action against infection. We therefore tested the hypothesis that bone marrow concentrated granulocytes precursors added to a standard bone graft could decrease the risk of recurrence of infection when single-stage treatment of infected tibial non-unions is performed with bone graft. During a single-stage procedure 40 patients with infected tibial non-union received a spongious bone graft supercharged with granulocytes precursors after debridement (study group). A control group (40 patients) was treated in a single stage with local debridement and standard bone graft obtained from the iliac crest. The antibiotic therapy protocol was the same (60 days) in the two groups. CFU-GM progenitors were harvested from bone marrow aspirated on the opposite iliac crest of the site where the cancellous bone was obtained. Union (radiographs and CT scan), a recurrence of clinical infection, and need for subsequent surgery were evaluated. Thirty-eight (95%) patients who received graft supercharged with granulocytes precursors achieved successful union without recurrence of infection during the seven-year follow-up versus 28 (70%) control patients; for the control group the mean graft resorption volume was 40%, while no bone graft resorption was found for the study group. Supercharging the cancellous bone graft with bone marrow granulocytes precursors protect the site of infected non-union from recurrence of infection and bone resorption of the graft.

  5. Thermodynamic analysis of single-stage and multi-stage adsorption refrigeration cycles with activated carbon–ammonia working pair

    International Nuclear Information System (INIS)

    Xu, S.Z.; Wang, L.W.; Wang, R.Z.

    2016-01-01

    Highlights: • Activated carbon–ammonia multi-stage adsorption refrigerator was analyzed. • COP, exergetic efficiency and entropy production of cycles were calculated. • Single-stage cycle usually has the advantages of simple structure and high COP. • Multi-stage cycles adapt to critical conditions better than single-stage cycle. • Boundary conditions for choosing optimal cycle were summarized as tables. - Abstract: Activated carbon–ammonia multi-stage adsorption refrigeration cycle was analyzed in this article, which realized deep-freezing for evaporating temperature under −18 °C with heating source temperature much lower than 100 °C. Cycle mathematical models for single, two and three-stage cycles were established on the basis of thorough thermodynamic analysis. According to simulation results of thermodynamic evaluation indicators such as COP (coefficient of performance), exergetic efficiency and cycle entropy production, multi-stage cycle adapts to high condensing temperature, low evaporating temperature and low heating source temperature well. Proposed cycle with selected working pair can theoretically work under very severe conditions, such as −25 °C evaporating temperature, 40 °C condensing temperature, and 70 °C heating source temperature, but under these working conditions it has the drawback of low cycle adsorption quantity. It was found that both COP and exergetic efficiency are of great reference value in the choice of cycle, whereas entropy production is not so useful for cycle stage selection. Finally, the application boundary conditions of single-stage, two-stage, and three-stage cycles were summarized as tables according to the simulation results, which provides reference for choosing optimal cycle under different conditions.

  6. Single-stage separation and esterification of cation salt carboxylates using electrodeionization

    Science.gov (United States)

    Lin, YuPo J.; Henry, Michael; Hestekin, Jamie; Snyder, Seth W.; St. Martin, Edward J.

    2006-11-28

    A method of and apparatus for continuously making an organic ester from a lower alcohol and an organic acid is disclosed. An organic acid or salt is introduced or produced in an electrode ionization (EDI) stack with a plurality of reaction chambers each formed from a porous solid ion exchange resin wafer interleaved between anion exchange membranes or an anion exchange membrane and a cation exchange membrane or an anion exchange membrane and a bipolar exchange membranes. At least some reaction chambers are esterification chambers and/or bioreactor chambers and/or chambers containing an organic acid or salt. A lower alcohol in the esterification chamber reacts with an anion to form an organic ester and water with at least some of the water splitting with the ions leaving the chamber to drive the reaction.

  7. Assessment of the pro-inflammatory activity of water sampled from ...

    African Journals Online (AJOL)

    2014-03-20

    Mar 20, 2014 ... Assessment of the pro-inflammatory activity of water sampled from major water treatment facilities ... Although these procedures have been used to assess the human health-related quality of water from ..... CITY OF TSHWANE (2003) Rietvlei Nature Reserve – historical back- ground. Water and Sanitation ...

  8. preconcentration of uranium in water samples using dispersive ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    extraction, co-precipitation and ion-exchange, electrodeposition [9-14] have been used in the ... This method uses an extracting solvent dissolved in a dispersive solvent, which is miscible with both extraction solvent and water. Methanol, acetonitrile and acetone have been used as ..... NASS-4-CRM are given in Table 5.

  9. COMPOSITE SAMPLING FOR DETECTION OF COLIFORM BACTERIA IN WATER SUPPLY

    Science.gov (United States)

    Low densities of coliform bacteria introduced into distribution systems may survive in protected habitats. These organisms may interfere with and cause confusion in the use of the coliforms as indicators of sewage contamination of drinking water. Methods of increasing the probabi...

  10. Identifying potential surface water sampling sites for emerging ...

    African Journals Online (AJOL)

    Emerging chemical pollutants (ECPs) are defined as new chemicals which do not have a regulatory status, but which may have an adverse effect on human health and the environment. The occurrence and concentrations of ECPs in South African water bodies are largely unknown, so monitoring is required in order to ...

  11. Sample container and storage for paclobutrazol monitoring in irrigation water

    Science.gov (United States)

    Paclobutrazol is a plant growth retardant commonly used on greenhouse crops. Residues from paclobutrazol applications can accumulate in recirculated irrigation water. Given that paclobutrazol has a long half-life and potential biological activity in parts per billion concentrations, it would be de...

  12. Beryllium-10 concentrations in water samples of high northern latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Strobl, C.; Eisenhauer, A.; Schulz, V.; Baumann, S.; Mangini, A. [Heidelberger Akademie der Wissenschaften, Heildelberg (Germany); Kubik, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    {sup 10}Be concentrations in the water column of high northern latitudes were not available so far. We present different {sup 10}Be profiles from the Norwegian-Greenland Sea, the Arctic Ocean, and the Laptev Sea. (author) 3 fig., 3 refs.

  13. High - velocity water jet impact on concrete samples

    Czech Academy of Sciences Publication Activity Database

    Mádr, V.; Uhlář, R.; Hlaváč, L. M.; Sitek, Libor; Foldyna, Josef; Hela, R.; Bodnárová, L.; Kaličinský, J.

    2009-01-01

    Roč. 2, č. 4 (2009), s. 43-48 ISSN 2067-3809 Institutional research plan: CEZ:AV0Z30860518 Keywords : water jet * concrete * depth of penetration * disintegration volume Subject RIV: JM - Building Engineering http://acta.fih.upt.ro/pdf/2009-4/ACTA-2009-4-08.pdf

  14. EPA Technology Available for Licensing: Portable Device to Concentrate Water Samples for Microorganism Analysis

    Science.gov (United States)

    Using a computer controlled system, this ultrafiltration device automates the process of concentrating a water sample and can be operated in the field. The system was also designed to reduce human exposure to potentially contaminated water.

  15. High-frequency isotopic analysis of liquid water samples in the field - initial results from continuous water sampling and cavity ring-down spectroscopy

    Science.gov (United States)

    von Freyberg, Jana; Studer, Bjørn; Kirchner, James

    2016-04-01

    Studying rapidly changing hydrochemical signals in catchments can help to improve our mechanistic understanding of their water flow pathways and travel times. For these purposes, stable water isotopes (18O and 2H) are commonly used as natural tracers. However, high-frequency isotopic analyses of liquid water samples are challenging. One must capture highly dynamic behavior with high precision and accuracy, but the lab workload (and sample storage artifacts) involved in collecting and analyzing thousands of bottled samples should also be avoided. Therefore, we have tested Picarro, Inc.'s newly developed Continuous Water Sampler Module (CoWS), which is coupled to their L2130-i Cavity Ring-Down Spectrometer to enable real-time on-line measurements of 18O and 2H in liquid water samples. We coupled this isotope analysis system to a dual-channel ion chomatograph (Metrohm AG, Herisau, Switzerland) for analysis of major cations and anions, as well as a UV-Vis spectroscopy system (s::can Messtechnik GmbH, Vienna, Austria) and electrochemical probes for characterization of basic water quality parameters. The system was run unattended for up to a week at a time in the laboratory and at a small catchment. At the field site, stream-water and precipitation samples were analyzed, alternating at sub-hourly intervals. We observed that measured isotope ratios were highly sensitive to the liquid water flow rate in the CoWS, and thus to the hydraulic head difference between the CoWS and the samples from which water was drawn. We used a programmable high-precision dosing pump to control the injection flow rate and eliminate this flow-rate artifact. Our experiments showed that the precision of the CoWS-L2130-i-system for 2-minute average values was typically better than 0.06‰ for δ18O and 0.16‰ for δ2H. Carryover effects were 1% or less between isotopically contrasting water samples for 30-minute sampling intervals. Instrument drift could be minimized through periodic analysis of

  16. “Nanofiltration” Enabled by Super-Absorbent Polymer Beads for Concentrating Microorganisms in Water Samples

    OpenAIRE

    Xie, Xing; Bahnemann, Janina; Wang, Siwen; Yang, Yang; Hoffmann, Michael R.

    2016-01-01

    Detection and quantification of pathogens in water is critical for the protection of human health and for drinking water safety and security. When the pathogen concentrations are low, large sample volumes (several liters) are needed to achieve reliable quantitative results. However, most microbial identification methods utilize relatively small sample volumes. As a consequence, a concentration step is often required to detect pathogens in natural waters. Herein, we introduce a novel water sam...

  17. The toxicity of MEA and amine waste water samples using standardised freshwater bioassays

    OpenAIRE

    Brooks, S.; Heiaas, H.; Lillicrap, A.

    2013-01-01

    Water samples provided by Tel-Tek AS were assessed for their toxicity to freshwater organisms from three trophic groups. The water samples included pure monoethanolamine (MEA) and two amine waste water mixtures described as Amine Reactor Waste (ARW) and treated amine waste water (TW). The toxicity of these three test solutions to the unicellular algae Pseudokirchneriella subcapitata, the freshwater crustacean Daphnia magna, and the embryos of the zebra fish Danio rerio were performed in accor...

  18. SEAMIST trademark soil sampling for tritiated water: First year's results

    International Nuclear Information System (INIS)

    Mallon, B.; Martins, S.A.; Houpis, J.L.; Lowry, W.; Cremer, C.D.

    1992-01-01

    SEAMIST trademark is a recently developed sampling system that enables one to measure various soil parameters by means of an inverted, removable, impermeable membrane tube inserted in a borehole. This membrane tube can have various measuring devices installed on it, such as gas ports, adsorbent pads, and electrical sensors. These membrane tubes are made of a laminated polymer. The Lawrence Livermore National Laboratory in Livermore, California, has installed two of these systems to monitor tritium in soil resulting from a leak in an underground storage tank. One tube is equipped with gas ports to sample soil vapor and the other with adsorbent pads to sample soil moisture. Borehole stability was maintained using either sand-filled or air-inflated tubes. Both system implementations yielded concentrations or activities that compared well with the measured concentrations of tritium in the soil taken during borehole construction. In addition, an analysis of the data suggest that both systems prevented the vertical migration of tritium in the boreholes. Also, a neutron probe was successfully used in a blank membrane inserted in one of the boreholes to monitor the moisture in the soil without exposing the probe to the tritium. The neutron log showed excellent agreement with the soil moisture content measured in soil samples taken during borehole construction. This paper describes the two SEAMIST trademark systems used and presents sampling results and comparisons

  19. UMTRA Project water sampling and analysis plan, Grand Junction, Colorado. Revision 1, Version 6

    International Nuclear Information System (INIS)

    1995-09-01

    This water sampling and analysis plan describes the planned, routine ground water sampling activities at the Grand Junction US DOE Uranium Mill Tailings Remedial Action (UMTRA) Project site (GRJ-01) in Grand Junction, Colorado, and at the Cheney Disposal Site (GRJ-03) near Grand Junction. The plan identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequencies for the routine monitoring stations at the sites. Regulatory basis is in the US EPA regulations in 40 CFR Part 192 (1994) and EPA ground water quality standards of 1995 (60 FR 2854). This plan summarizes results of past water sampling activities, details water sampling activities planned for the next 2 years, and projects sampling activities for the next 5 years

  20. Single stage reconstruction of ruptured tendoachilles tendon with skin cover using distally based superficial sural artery flap.

    Science.gov (United States)

    Abhyankar, Suhas V; Kulkarni, Ananta; Agarwal, Naveen Kumar

    2009-10-01

    Ruptured tendoachilles along with skin defect is a complex problem to reconstruct. Both things require a priority. Single stage reconstruction of ruptured tendoachilles tendon with skin cover using distally based superficial sural arterial flap allows us to perform both. This procedure gives excellent result, shortens the stay, thereby reducing the cost. This method is a simple solution to the complex problem like ruptured tendoachilles with skin defect. In this study, 6 patients with rupture of tendoachilles tendon due to penetrating injury, with skin defect are presented. The repair was done using aponeurotic part of tendoachilles tendon, taken from proximal part of tendoachilles in the midline measuring around 2 to 2.5 cm in width and 8 to 10 cm in length, with intact distal attachment. The tendon was turned upside down by 180 degrees and sutured to the distal stump of the tendoachilles tendon without tension. The skin defect was covered using distally based superficial sural artery flap in the same sitting. The follow-up period was 9 to 30 months. All patients showed good results. In one patient there was distal necrosis of 1.5 cm of the distally based superficial sural artery flap, which healed satisfactorily with conservative treatment. Single stage tendoachilles reconstruction can be used with good functional result and patient satisfaction.

  1. Total and inorganic arsenic in fish samples from Norwegian waters.

    Science.gov (United States)

    Julshamn, Kaare; Nilsen, Bente M; Frantzen, Sylvia; Valdersnes, Stig; Maage, Amund; Nedreaas, Kjell; Sloth, Jens J

    2012-01-01

    The contents of total arsenic and inorganic arsenic were determined in fillet samples of Northeast Artic cod, herring, mackerel, Greenland halibut, tusk, saithe and Atlantic halibut. In total, 923 individual fish samples were analysed. The fish were mostly caught in the open sea off the coast of Norway, from 40 positions. The determination of total arsenic was carried out by inductively coupled plasma mass spectrometry following microwave-assisted wet digestion. The determination of inorganic arsenic was carried out by high-performance liquid chromatography-ICP-MS following microwave-assisted dissolution of the samples. The concentrations found for total arsenic varied greatly between fish species, and ranged from 0.3 to 110 mg kg(-1) wet weight. For inorganic arsenic, the concentrations found were very low (level in fish used in the recent EFSA opinion on arsenic in food.

  2. Total and inorganic arsenic in fish samples from Norwegian waters

    DEFF Research Database (Denmark)

    Julshamn, K.; Nilsen, B. M.; Frantzen, S.

    2012-01-01

    The contents of total arsenic and inorganic arsenic were determined in fillet samples of Northeast Arctic cod, herring, mackerel, Greenland halibut, tusk, saithe and Atlantic halibut. In total, 923 individual fish samples were analysed. The fish were mostly caught in the open sea off the coast...... of Norway, from 40 positions. The determination of total arsenic was carried out by inductively coupled plasma mass spectrometry following microwave-assisted wet digestion. The determination of inorganic arsenic was carried out by high-performance liquid chromatography–ICP-MS following microwave......-assisted dissolution of the samples. The concentrations found for total arsenic varied greatly between fish species, and ranged from 0.3 to 110 mg kg–1 wet weight. For inorganic arsenic, the concentrations found were very low (...

  3. UMTRA Project water sampling and analysis plan, Gunnison, Colorado: Revision 1

    International Nuclear Information System (INIS)

    1994-11-01

    This water sampling and analysis plan summarizes the results of previous water sampling activities and the plan for future water sampling activities, in accordance with the Guidance Document for Preparing Sampling and Analysis Plans for UMTRA Sites. A buffer zone monitoring plan for the Dos Rios Subdivision is included as an appendix. The buffer zone monitoring plan was developed to ensure continued protection to the public from residual contamination. The buffer zone is beyond the area depicted as contaminated ground water due to former milling operations. Surface remedial action at the Gunnison Uranium Mill Tailings Remedial Action Project site began in 1992; completion is expected in 1995. Ground water and surface water will be sampled semiannually at the Gunnison processing site and disposal site. Results of previous water sampling at the Gunnison processing site indicate that ground water in the alluvium is contaminated by the former uranium processing activities. Background ground water conditions have been established in the uppermost aquifer at the Gunnison disposal site. The monitor well locations provide a representative distribution of sampling points to characterize ground water quality and ground water flow conditions in the vicinity of the sites. The list of analytes has been modified with time to reflect constituents that are related to uranium processing activities and the parameters needed for geochemical evaluation

  4. Presence of enteric viruses in water samples for consumption in Colombia: Challenges for supply systems.

    Science.gov (United States)

    Peláez, Dioselina; Guzmán, Blanca Lisseth; Rodríguez, Johanna; Acero, Felipe; Nava, Gerardo

    2016-04-15

    Since drinking water can be a vehicle for the transmission of pathogens, the detection of enteric viruses in these water samples is essential to establish the appropriate measures to control and prevent associated diseases.  To analyze the results obtained for enteric viruses in water samples for human consumption received at the Colombian Instituto Nacional de Salud and establish their association with the data on water quality in Colombian municipalities.  We conducted a descriptive-retrospective analysis of the results obtained in the detection of rotavirus, enterovirus, hepatitis A virus and adenovirus in water samples received for complementary studies of enteric hepatitis, acute diarrheal disease and foodborne diseases. Data were correlated with the results of water quality surveillance determined by the national human consumption water quality index (IRCA).  Of the 288 samples processed from 102 Colombian municipalities, 50.7% were positive for viruses: 26.73% for hepatitis A virus, 20.48% for enterovirus and rotavirus and 18.05% for adenovirus. Viruses were detected in 48.26% of non-treated water samples and in 45.83% of treated water samples. The IRCA index showed no correlation with the presence of viruses.  The presence of viruses in water represents a public health risk and, therefore, the prevention of virus transmission through water requires appropriate policies to reinforce water supply systems and improve epidemiological surveillance.

  5. The representativeness of pore water samples collected from the unsaturated zone using pressure-vacuum lysimeters

    Science.gov (United States)

    Peters, C.A.; Healy, R.W.

    1988-01-01

    Studies have indicated that the chemistry of water samples may be altered by the collection technique, creating concern about the representativeness of the pore water samples obtained. A study using soil water pressure-vacuum lysimeters in outwash sand and glacial till deposits demonstrates that for non-dilute-solution samples the effect of pH of sampling with lysimeters is minimal, and that measured major cation and anion concentrations are representative of the natural pore water; trace-metal concentrations can be significantly altered by collection procedures at low concentrations. -from Authors

  6. Speciation of phosphorus oxoacids in natural and waste water samples.

    Science.gov (United States)

    Valls-Cantenys, Carme; Iglesias, Mònica; Todolí, José Luís; Salvadó, Victòria

    2012-03-30

    Phosphorus is a key nutrient and in natural environments regulates trophic status and consequently water quality. Therefore monitoring of phosphorus content in natural and wastewater is essential. Although several phosphorus species can be found in the environment, the majority of the methods developed are for orthophosphate determination. High performance liquid chromatography (HPLC) coupled with inductively coupled plasma with atomic emission spectroscopy (ICP-AES) has been first used in this study for the speciation of the most common phosphorus oxoanions in aquatic environments: orthophosphate, phosphite, hypophosphite, pyrophosphate and tripolyphosphate. The chromatograms have been obtained by registering the phosphorous 213.618 nm emission intensity variation with time. The pH and the ionic strength of the mobile phase have been the most critical variables of the chromatographic separation. Moreover, methanol addition promotes the elution of the most retained species. Finally, by using ammonium nitrate and a gradient elution, increasing ionic strength and decreasing the pH, the separation has been achieved in 12 min. Limits of detection have been included within the 1-5 mg L(-1) range. The developed methodology has been tested with spiked tap water and effluent water of a wastewater treatment plant (WWTP) obtaining recoveries in the range of 91.5-114.1% for a 20 mg P L(-1) spike concentration. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Occurrence of [i]Leptospira[/i] DNA in water and soil samples collected in eastern Poland

    Directory of Open Access Journals (Sweden)

    Angelina Wójcik-Fatla

    2014-11-01

    Full Text Available [i]Leptospira[/i] is an important re-emerging zoonotic human pathogen, disseminated by sick and carrier animals, water and soil. Weather calamities, such as flooding or cyclones favour the spreading of these bacteria. To check a potential role of natural water and soil in the persistence and spread of [i]Leptospira [/i]on the territory of eastern Poland, 40 samples of natural water and 40 samples of soil were collected from areas exposed to flooding, and 64 samples of natural water and 68 samples of soil were collected from areas not exposed to flooding. Samples of water were taken from various reservoirs (rivers, natural lakes, artificial lakes, canals, ponds, farm wells and samples of soils were taken at the distance of 1–3 meters from the edge of the reservoirs. The samples were examined for the presence of [i]Leptospira[/i] DNA by nested-PCR. Two out of 40 samples of water (5.0% collected from the area exposed to flooding showed the presence of [i]Leptospira[/i] DNA, while all 40 samples of soil from this area were negative. All samples of water and soil (64 and 68, respectively collected from the areas not exposed to flooding were negative. No significant difference were found between the results obtained in the areas exposed and not exposed to flooding. In conclusion, these results suggest that water and soil have only limited significance in the persistence and dissemination of [i]Leptospira[/i] in eastern Poland.

  8. 400 area secondary cooling water sampling and analysis plan

    Energy Technology Data Exchange (ETDEWEB)

    Penn, L.L.

    1996-10-29

    This is a total rewrite of the Sampling and Analysis Plan in response to, and to ensure compliance with, the State Waste Discharge Permit ST 4501 issued on July 31, 1996. This revision describes changes in facility status and implements requirements of the permit.

  9. Enhanced Hydrogen Production Integrated with CO2 Separation in a Single-Stage Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Shwetha Ramkumar; Mahesh Iyer; Danny Wong; Himanshu Gupta; Bartev Sakadjian; Liang-Lhih Fan

    2008-09-30

    High purity hydrogen is commercially produced from syngas by the Water Gas Shift Reaction (WGSR) in high and low temperature shift reactors using iron oxide and copper catalysts respectively. However, the WGSR is thermodynamically limited at high temperatures towards hydrogen production necessitating excess steam addition and catalytic operation. In the calcium looping process, the equilibrium limited WGSR is driven forward by the incessant removal of CO{sub 2} by-product through the carbonation of calcium oxide. At high pressures, this process obviates the need for a catalyst and excess steam requirement, thereby removing the costs related to the procurement and deactivation of the catalyst and steam generation. Thermodynamic analysis for the combined WGS and carbonation reaction was conducted. The combined WGS and carbonation reaction was investigated at varying pressures, temperatures and S/C ratios using a bench scale reactor system. It was found that the purity of hydrogen increases with the increase in pressure and at a pressure of 300 psig, almost 100% hydrogen is produced. It was also found that at high pressures, high purity hydrogen can be produced using stoichiometric quantities of steam. On comparing the catalytic and non catalytic modes of operation in the presence of calcium oxide, it was found that there was no difference in the purity of hydrogen produced at elevated pressures. Multicyclic reaction and regeneration experiments were also conducted and it was found that the purity of hydrogen remains almost constant after a few cycles.

  10. Advanced exergy analysis applied to a single-stage heat transformer

    International Nuclear Information System (INIS)

    Colorado, D.

    2017-01-01

    Highlights: • Endogenous, exogenous, avoidable and unavoidable exergy destruction was calculated for a heat transformer. • 14.78% of the total exergy destruction could be reduced assuming improvements in the efficiency and design of the equipment. • A parametric study was discussed considering variations in the operation conditions. - Abstract: This study presents an advanced exergy analysis of a single-state absorption heat transformer operating with a lithium bromide water solution. A traditional exergy analysis was also conducted to identify the components with the highest contribution to the exergy destruction, and an advanced exergy approach was developed to estimate a realistic design and improve the operating conditions of the system. According to the base case of this study, when calculating the total reversibility of the cycle, only 14.78% could be reduced by improving its design and configuration. In addition, a parametric study was presented to discuss the sensitivity of splitting exergy destruction concepts taking into account temperature variations in the heat source, sink, and seawater outlet. Considering improvements to the generator a top priority, followed by improving the absorber, the condenser and finally the evaporator. The numerical results of this work have been developed to help design engineers experiment and assemble future equipment.

  11. UMTRA Project water sampling and analysis plan, Belfield and Bowman, North Dakota

    International Nuclear Information System (INIS)

    1994-08-01

    Surface remedial action is scheduled to begin at the Belfield and Bowman Uranium Mill Tailings Remedial Action (UMTRA) Project sites in the spring of 1996. Water sampling was conducted in 1993 at both the Belfield processing site and the Bowman processing/disposal site. Results of the sampling at both sites indicate that ground water conditions have remained relatively stable over time. Water sampling activities are not scheduled for 1994 because ground water conditions at the two sites are relatively stable, the 1993 sampling was comprehensive, and surface remediation activities are not scheduled to start until 1996. The next water sampling event is scheduled before the start of remedial activities and will include sampling selected monitor wells at both sites and several domestic wells in the vicinity

  12. Presence of Cryptosporidium parvum and Giardia lamblia in water samples from Southeast Asia: towards an integrated water detection system.

    Science.gov (United States)

    Kumar, Thulasi; Abd Majid, Mohamad Azlan; Onichandran, Subashini; Jaturas, Narong; Andiappan, Hemah; Salibay, Cristina C; Tabo, Hazel A L; Tabo, Norbel; Dungca, Julieta Z; Tangpong, Jitbanjong; Phiriyasamith, Sucheep; Yuttayong, Boonyaorn; Polseela, Raxsina; Do, Binh Nhu; Sawangjaroen, Nongyao; Tan, Tian-Chye; Lim, Yvonne A L; Nissapatorn, Veeranoot

    2016-01-13

    Access to clean and safe drinking water that is free from pathogenic protozoan parasites, especially Cryptosporidium parvum and Giardia lamblia that cause gastrointestinal illness in humans, is still an issue in Southeast Asia (SEA). This study is the first attempt to detect the aforementioned protozoan parasites in water samples from countries in SEA, using real-time polymerase chain reaction (qPCR) assays. A total of 221 water samples of 10 l each were collected between April and October 2013 from Malaysia (53), Thailand (120), the Philippines (33), and Vietnam (15). A physicochemical analysis was conducted. The water samples were processed in accordance with the US Environmental Protection Agency's methods 1622/1623.1, microscopically observed and subsequently screened using qPCR assays. Cryptosporidium oocysts were detected in treated water samples from the Philippines (1/10), with a concentration of 0.06 ± 0.19 oocyst/L, and untreated water samples from Thailand (25/93), Malaysia (17/44), and the Philippines (11/23), with concentrations ranging from 0.13 ± 0.18 to 0.57 ± 1.41 oocyst/L. Giardia cysts were found in treated water samples from the Philippines (1/10), with a concentration of 0.02 ± 0.06 cyst/L, and in untreated water samples from Thailand (20/93), Vietnam (5/10), Malaysia (22/44), and the Philippines (16/23), with concentrations ranging from 0.12 ± 0.3 to 8.90 ± 19.65 cyst/L. The pathogens C. parvum and G. lamblia were detected using using qPCR assays by targeting the 138-bp fragment and the small subunit gene, respectively. C. parvum was detected in untreated water samples from the Philippines (1/23) and Malaysia (2/44), whilst, G. lamblia detected was detected in treated water samples from the Philippines (1/10) and in untreated water samples from Thailand (21/93), Malaysia (12/44), and the Philippines (17/23). Nitrate concentration was found to have a high positive correlation with (oo)cyst (0.993). The presence of

  13. Concentration of polycyclic aromatic hydrocarbons in water samples from different stages of treatment

    Science.gov (United States)

    Pogorzelec, Marta; Piekarska, Katarzyna

    2017-11-01

    The aim of this study was to analyze the presence and concentration of selected polycyclic aromatic hydrocarbons in water samples from different stages of treatment and to verify the usefulness of semipermeable membrane devices for analysis of drinking water. For this purpose, study was conducted for a period of 5 months. Semipermeable membrane devices were deployed in a surface water treatment plant located in Lower Silesia (Poland). To determine the effect of water treatment on concentration of PAHs, three sampling places were chosen: raw water input, stream of water just before disinfection and treated water output. After each month of sampling SPMDs were changed for fresh ones and prepared for further analysis. Concentrations of fifteen polycyclic aromatic hydrocarbons were determined by high performance liquid chromatography (HPLC). Presented study indicates that the use of semipermeable membrane devices can be an effective tool for the analysis of aquatic environment, including monitoring of drinking water, where organic micropollutants are present at very low concentrations.

  14. Procedures for field chemical analyses of water samples

    International Nuclear Information System (INIS)

    Korte, N.; Ealey, D.

    1983-12-01

    A successful water-quality monitoring program requires a clear understanding of appropriate measurement procedures in order to obtain reliable field data. It is imperative that the responsible personnel have a thorough knowledge of the limitations of the techniques being used. Unfortunately, there is a belief that field analyses are simple and straightforward. Yet, significant controversy as well as misuse of common measurement techniques abounds. This document describes procedures for field measurements of pH, carbonate and bicarbonate, specific conductance, dissolved oxygen, nitrate, Eh, and uranium. Each procedure section includes an extensive discussion regarding the limitations of the method as well as brief discussions of calibration procedures and available equipment. A key feature of these procedures is the consideration given to the ultimate use of the data. For example, if the data are to be used for geochemical modeling, more precautions are needed. In contrast, routine monitoring conducted merely to recognize gross changes can be accomplished with less effort. Finally, quality assurance documentation for each measurement is addressed in detail. Particular attention is given to recording sufficient information such that decisions concerning the quality of the data can be easily made. Application of the procedures and recommendations presented in this document should result in a uniform and credible water-quality monitoring program. 22 references, 4 figures, 3 tables

  15. Single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation in surgical treatment for single-segment lumbar spinal tuberculosis

    OpenAIRE

    Zeng, Hao; Wang, Xiyang; Zhang, Penghui; Peng, Wei; Zhang, Yupeng; Liu, Zheng

    2015-01-01

    Objective: The aim of this study is to determine the feasibility and efficacy of surgical management of single-segment lumbar spinal tuberculosis (TB) by using single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation.Methods: Seventeen cases of single-segment lumbar TB were treated with single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reco...

  16. Determination of rare earth elements in natural water samples – A review of sample separation, preconcentration and direct methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Andrew, E-mail: afisher@plymouth.ac.uk [School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, Devon, PL4 8AA (United Kingdom); Kara, Derya [Department of Chemistry, Art and Science Faculty, Balikesir University, 10100, Balikesir (Turkey)

    2016-09-07

    This review discusses and compares the methods given for the determination of rare earth elements (REE) in natural water samples, including sea, river, lake, tap, ground and waste waters as well as Antarctic ice. Since REE are at very low concentrations in natural waters, numerous different preconcentration methods have been proposed to enable their measurement. These include liquid liquid extraction, dispersive liquid-liquid micro-extraction and solidified floating drop micro-extraction. In addition to liquid-liquid extraction methods, solid phase extraction using commercial resins, resins made in-house, silica-based exchange materials and other solid media is also discussed. These and other techniques such as precipitation/co-precipitation and flotation are compared in terms of speed, preconcentration factors achieved, precision, accuracy and limits of detection (LOD). Some papers have discussed the direct determination of REE in these sample types. Some have used specialised sample introduction systems such as ultrasonic nebulization whereas others have used a standard sample introduction system coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection. These direct methods have also been discussed and compared. - Highlights: • The determination of rare earth elements in waters is reviewed. • Assorted preconcentration techniques are discussed and evaluated. • Detection techniques include atomic spectrometry, potentiometry and spectrophotometry. • Special nebulisers and electrothermal vaporization approaches are reviewed.

  17. Results of single-staged rotational osteotomy in a child with congenital proximal radioulnar synostosis: subjective and objective evaluation.

    Science.gov (United States)

    Shingade, Viraj U; Shingade, Rashmi V; Ughade, Suresh N

    2014-01-01

    For congenital proximal radioulnar synostosis, both conservative and operative treatments have been described. Most of the studies describing surgical interventions are based on subjective evaluation of the forearm function and have used severe degree of forearm pronation as an indication for surgery. This study describes a single-staged rotational osteotomy of the proximal third ulna and distal third radius. The aim of the study was to assess the utility of the described surgical procedure by subjective and objective evaluations of the forearm function. Forty-eight children with congenital proximal radioulnar synostosis were evaluated by subjective and objective assessments and were followed up prospectively. Subjective evaluation consisted of a set of 12 questions regarding the basic activities of life. Objective evaluation was made using the Jebsen-Taylor hand-function test and a classification system used by Failla and colleagues for 15 tasks described by Morrey and colleagues. Eleven children were treated conservatively. Thirty-six children underwent a single-staged rotational osteotomy of the proximal third ulna and distal third radius. After surgery, the evaluations were repeated. The mean age at surgery was 8.6±3.7 years, and the mean postoperative follow-up period was 54±13 months. All operated forearms showed a statistically significant improvement in functioning after surgery as per the subjective and objective evaluations. The mean time taken to carry out all activities before surgery was 47.7+10.0 seconds, which significantly reduced to 33.3+6.6 seconds after surgery (P=0.0001) as per the results of the Jebsen-Taylor hand-function test. All good (n=19) and fair (n=11) results were converted to excellent (n=30) after surgery as per the modified Failla classification. There were no neurovascular injuries as compared with other published techniques. Only 1 child had delayed union, and 1 had persistent dorsal angulation at the radial osteotomy site. For

  18. UMTRA Project water sampling and analysis plan, Gunnison, Colorado. Revision 2

    International Nuclear Information System (INIS)

    1995-09-01

    Surface remedial action at the Gunnison Uranium Mill Tailings Remedial Action Project site began in 1992; completion is expected in 1995. Ground water and surface water will be sampled semiannually at the Gunnison processing site (GUN-01) and disposal site (GUN-08). Results of previous water sampling at the Gunnison processing site indicate that ground water in the alluvium is contaminated by the former uranium processing activities. Background ground water conditions have been established in the uppermost aquifer (Tertiary gravels) at the Gunnison disposal site. Semiannual water sampling is scheduled for the spring and fall. Water quality sampling is conducted at the processing site (1) to ensure protection of human health and the environment, (2) for ground water compliance monitoring during remedial action construction, and (3) to define the extent of contamination. At the processing site, the frequency and duration of sampling will be dependent upon the nature and extent of residual contamination and the compliance strategy chosen. The monitor well locations provide a representative distribution of sampling points to characterize ground water quality and ground water flow conditions in the vicinity of the sites. The list of analytes has been modified with time to reflect constituents that are related to uranium processing activities and the parameters needed for geochemical evaluation

  19. Assessment of Some Heavy Metals in Drinking Water Samples of Tunceli, Turkey

    Directory of Open Access Journals (Sweden)

    Olcay Kaplan

    2011-01-01

    Full Text Available The drinking water quality is associated with the conditions of the water supply networks, the pollution and the contamination of groundwater with pollutants of both anthropogenic and natural origin. In this study, water samples were taken from four different waterworks in Tunceli, Turkey and heavy metals concentrations (As, Cu, Cd, Cr, Pb, Ni and Hg were measured. Four sampling sites were pre-defined in different locations of the city. The obtained results showed that, the heavy metals concentrations in water samples did not exceed the values of WHO (World Health Organization, EC (Europe Community, EPA (Environment Protection Agency and TSE-266 (Turkish Standard guidelines.

  20. Uranium content measurement in drinking water samples using track etch technique

    International Nuclear Information System (INIS)

    Kumar, Mukesh; Kumar, Ajay; Singh, Surinder; Mahajan, R.K.; Walia, T.P.S.

    2003-01-01

    The concentration of uranium has been assessed in drinking water samples collected from different locations in Bathinda district, Punjab, India. The water samples are taken from hand pumps and tube wells. Uranium is determined using fission track technique. Uranium concentration in the water samples varies from 1.65±0.06 to 74.98±0.38 μg/l. These values are compared with safe limit values recommended for drinking water. Most of the water samples are found to have uranium concentration above the safe limit. Analysis of some heavy metals (Zn, Cd, Pb and Cu) in water is also done in order to see if some correlation exists between the concentration of uranium and these heavy metals. A weak positive correlation has been observed between the concentration of uranium and heavy metals of Pb, Cd and Cu

  1. USDA Forest Service national protocols for sampling air pollution-sensitive waters

    Science.gov (United States)

    T. J. Sullivan

    2012-01-01

    The first step in designing a surface water sampling program is identifying one or more problems or questions that require information on water quality. Common water quality problems include nutrient enrichment (from a variety of causes), effects of atmospheric deposition (acidification, eutrophication, toxicity), and effects of major disturbances such as fire or pest...

  2. Evaluation of the Bacterial Status of Water Samples at Umudike Abia ...

    African Journals Online (AJOL)

    77.78%), Proteus spp.(66.67%), Serratia spp.(55.5%) and Vibro spp.(22.2%). The occurrence of the water borne pathogens appeared limited to the stream water samples, hence, continuous consumption without adequate treatment is potentially dangerous. Keywords: Water, rainwater, stream, bacteria, coliforms, pathogen ...

  3. UMTRA Project water sampling and analysis plan, Durango, Colorado. Revision 1

    International Nuclear Information System (INIS)

    1995-09-01

    Planned, routine ground water sampling activities at the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site in Durango, Colorado, are described in this water sampling and analysis plan. The plan identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the routine monitoring stations at the site. The ground water data are used to characterize the site ground water compliance strategies and to monitor contaminants of potential concern identified in the baseline risk assessment (DOE, 1995a). Regulatory basis for routine ground water monitoring at UMTRA Project sites is derived from the US EPA regulations in 40 CFR Part 192 (1994) and EPA standards of 1995 (60 FR 2854). Sampling procedures are guided by the UMTRA Project standard operating procedures (SOP) (JEG, n.d.), the Technical Approach Document (TAD) (DOE, 1989), and the most effective technical approach for the site

  4. A Rocket Powered Single-Stage-to-Orbit Launch Vehicle With U.S. and Soviet Engineers

    Science.gov (United States)

    MacConochie, Ian O.; Stnaley, Douglas O.

    1991-01-01

    A single-stage-to-orbit launch vehicle is used to assess the applicability of Soviet Energia high-pressure-hydrocarbon engine to advanced U.S. manned space transportation systems. Two of the Soviet engines are used with three Space Shuttle Main Engines. When applied to a baseline vehicle that utilized advanced hydrocarbon engines, the higher weight of the Soviet engines resulted in a 20 percent loss of payload capability and necessitated a change in the crew compartment size and location from mid-body to forebody in order to balance the vehicle. Various combinations of Soviet and Shuttle engines were evaluated for comparison purposes, including an all hydrogen system using all Space Shuttle Main Engines. Operational aspects of the baseline vehicle are also discussed. A new mass properties program entitles Weights and Moments of Inertia (WAMI) is used in the study.

  5. Advantages of using a two-switch forward in single-stage power factor corrected power supplies

    DEFF Research Database (Denmark)

    Petersen, Lars

    2000-01-01

    A single-stage power factor corrected power supply using a two-switch forward is proposed to increase efficiency. The converter is operated in the DCM (discontinues conduction mode) and it is shown that this operation mode ensures the intermediate DC-bus to be controlled only by means of circuit...... parameters and therefore independent of load variations. The DCM operation often has a diminishing effect on the efficiency but by use of the two-switch topology high efficiency with minimum circuit complexity can be achieved in this mode. A 500 W 70 V prototype of the two-switch boost-forward PFC power...... supply has been implemented. The measured efficiency is between 85% and 88.5% in the range 30 W-500 W and the measured power factor at full load is 0.95....

  6. Bilateral Simultaneous Revision Total Knee Arthroplasty as a Single Staged Procedure: A Case Report and Review of Literature.

    Science.gov (United States)

    Vaishya, Raju; Agarwal, Amit Kumar; Jaiswal, Chirag; Vijay, Vipul; Vaish, Abhishek

    2017-03-23

    Bilateral revision total knee arthroplasty (TKA) is a surgical procedure, which is rarely done simultaneously as it is a difficult surgery and the safety of simultaneous bilateral single stage surgery remains unknown. We report a case of a 67-year-old woman who presented to us with bilateral painful and unstable TKA (right > left) of six months duration. The primary bilateral TKA were done 14 years ago. Bilateral simultaneous revision TKA was performed, using cemented, constrained, long-stem prostheses. The intraoperative and postoperative periods remained uneventful. At last follow-up at four years, she had a pain-free range of motion of up to 0-115°, and the patient had returned to the activities of daily living. She had stable knees with good function and no evidence of loosening or wear.

  7. A rapid method for optimization of the rocket propulsion system for single-stage-to-orbit vehicles

    Science.gov (United States)

    Eldred, C. H.; Gordon, S. V.

    1976-01-01

    A rapid analytical method for the optimization of rocket propulsion systems is presented for a vertical take-off, horizontal landing, single-stage-to-orbit launch vehicle. This method utilizes trade-offs between propulsion characteristics affecting flight performance and engine system mass. The performance results from a point-mass trajectory optimization program are combined with a linearized sizing program to establish vehicle sizing trends caused by propulsion system variations. The linearized sizing technique was developed for the class of vehicle systems studied herein. The specific examples treated are the optimization of nozzle expansion ratio and lift-off thrust-to-weight ratio to achieve either minimum gross mass or minimum dry mass. Assumed propulsion system characteristics are high chamber pressure, liquid oxygen and liquid hydrogen propellants, conventional bell nozzles, and the same fixed nozzle expansion ratio for all engines on a vehicle.

  8. The Naso-labial and lateral forehead flaps as a single stage: A case report and review of literature

    Directory of Open Access Journals (Sweden)

    Adigun I

    2008-01-01

    Full Text Available We present here the case of a patient with a major traumatic nasal loses who had a near-total nasal reconstruction as a single-stage procedure. A 35 year-old civil servant who was involved in a road traffic injury about two years before presentation. He sustained extensive and multiple facial injuries with complete loss of nasal cover and lining. Reconstruction was performed by using superiorly based, bilateral, nasolabial flaps to line the floor and the nasal septum, and a paramedian forehead flap for skin cover. The patient did well postoperatively and was discharged home on the 7 th postoperative day. If the principles concerning cover, support, and lining are adhered to, excellent functional and aesthetic results can be achieved as we have obtained in our patient.

  9. Single stage concrete pumping through 2.432 km (1.51 miles: Weather and execution challenges

    Directory of Open Access Journals (Sweden)

    Chetan Hazaree

    2015-12-01

    Full Text Available This paper describes the execution challenges faced during single stage pumping of concrete through 2.432 km. Pump and pipeline selection and installation, materials’ development, establishing of control points and controlling variations are discussed. Concrete responses to weather changes play a vital role in concreting and pumping methodology development. Measuring pump pressure during pumping can provide insightful guidance to concreting. In order to optimize concrete mixtures, distance-specific mixture designs were developed and a relation between air-free paste volume (AFPV and pumping distance is derived. Pipeline priming and washout procedures specific to long-distance pumping are elaborated in detail. The paper presents a broad understanding regarding the challenges encountered; changes in pumping distance, materials, and climate would change the approach to solutions.

  10. Set up of an automatic water quality sampling system in irrigation agriculture

    OpenAIRE

    Heinz, Emanuel; Kraft, Philipp; Buchen, Caroline; Frede, Hans-Georg; Aquino, Eugenio; Breuer, Lutz

    2014-01-01

    We have developed a high-resolution automatic sampling system for continuous in situ measurements of stable water isotopic composition and nitrogen solutes along with hydrological information. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water) in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS) for stable w...

  11. National Coral Reef Monitoring Program: Water Chemistry of the Coral Reefs in American Samoa from Water Samples collected since 2015

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Water samples are collected and analyzed to assess spatial and temporal variation in the seawater carbonate systems of coral reef ecosystems in the Hawaiian and...

  12. Comparison of the mutagenic activity of XAD4 and blue rayon extracts of surface water and related drinking water samples.

    Science.gov (United States)

    Kummrow, Fábio; Rech, Celia M; Coimbrão, Carlos A; Roubicek, Deborah A; Umbuzeiro, Gisela de A

    2003-11-10

    The combination of mutagenicity tests and selective extraction methodologies can be useful to indicate the possible classes of genotoxic organic contaminants in water samples. Treated and source water samples from two sites were analyzed: a river under the influence of an azo dye-processing plant discharge and a reservoir not directly impacted with industrial discharges, but contaminated with untreated domestic sewage. Organic extraction was performed in columns packed with XAD4 resin, that adsorbs a broad class of mutagenic compounds like polycyclic aromatic hydrocarbons (PAHs), arylamines, nitrocompounds, quinolines, antraquinones, etc., including the halogenated disinfection by-products; and with blue rayon that selectively adsorbs polycyclic planar structures. The organic extracts were tested for mutagenicity with the Salmonella assay using TA98 and TA100 strains and the potencies were compared. A protocol for cleaning the blue rayon fibers was developed and the efficiency of the reused fibers was analyzed with spiked samples. For the river water samples under the influence of the azo-type dye-processing plant, the mutagenicity was much higher for both blue rayon and XAD4 extracts when compared to the water from the reservoir not directly impacted with industrial discharges. For the drinking water samples, although both sites showed mutagenic responses with XAD4, only samples from the site under the influence of the industrial discharge showed mutagenic activity with the blue rayon extraction, suggesting the presence of polycyclic compounds in those samples. As expected, negative results were found with the blue rayon extracts of the drinking water collected from the reservoir not contaminated with industrial discharges. In this case, it appears that using the blue rayon to extract drinking water samples and comparing the results with the XAD resin extracts we were able to distinguish the mutagenicity caused by industrial contaminants from the halogenated

  13. A study on the prevalence of Aeromonas spp. and its enterotoxin genes in samples of well water, tap water, and bottled water

    Directory of Open Access Journals (Sweden)

    Hareesh Didugu

    2015-10-01

    Full Text Available Aim: The aim of this work was to study the prevalence of Aeromonas spp. and its enterotoxin genes in various water sources. Materials and Methods: 125 samples (50 from well water, 50 from tap water, and 25 from bottled water were collected from various sources in and around Greater Hyderabad Municipal Corporation and examined for the presence of aeromonads by both cultural and polymerase chain reaction (PCR assay. Alkaline peptone water with ampicillin was used as enrichment. Aeromonas isolation medium and ampicillin dextrin agar were used as selective media. The boiling and snap chilling method was used for DNA extraction. Primers targeted against 16S rRNA, aer, and ast were used to identify aeromonads and its enterotoxins. Results: 48%, 18%, and 12% of well water, tap water, and bottled water samples were found positive by cultural assay with an overall prevalence of 28.8%. Aeromonads were detected in 32 % (52% in well water, 20% in tap water, and 16% in bottled water of samples by PCR assay. Aerolysin (aer gene was noticed in 34.6%, 20%, and 0% of well water, tap water, and bottled water samples, respectively, with an overall prevalence of 27.5%. Thermostable cytotonic enterotoxin (ast was observed in 37.5% (42.3% in well water, 30% in tap water, and 25% in bottled mineral water of samples. Conclusions: Presence of aeromonads and its toxin genes in various sources of water is of public health concern and emphasizes the need for necessary preventive measures to tackle the problem.

  14. A new collector for in situ pore water sampling in wetland sediment.

    Science.gov (United States)

    Gao, Feng; Deng, Jiancai; Li, Qinqin; Hu, Liuming; Zhu, Jinge; Hang, Hongjuan; Hu, Weiping

    2012-01-01

    Currently available pore water samplers generally do not allow continuous monitoring of temporal variations in pore water composition. Therefore, a new type of pore water collector was designed and constructed. These collectors were constructed of polyvinyl chloride (PVC) materials, including PVC tubing with one end sealed and another end topped with a removable PVC screw-cap. A row of holes was drilled 10 cm from the sealed end of each collector. These new collectors were deployed in different layers of the sediment in a constructed wetland in Lake Taihu, China, to reveal variations in the nutrient composition of pore water with high spatial and temporal resolution. Specifically, the collectors were driven into the sediment, and the pore water flowed into the tubing via gravity. The pore water was then sampled from the PVC tubing using a portable vacuum pump, and then was taken to the lab within 20 min for analysis of the dissolved oxygen (DO) and nutrient concentration. The DO concentration of the pore water was below the detection limit for all samples, indicating that the pore water was probably not influenced by the air and that the water in the collector tube was representative of the pore water. These findings suggest that the collector is capable of measuring the temporal and spatial variations in the nutrient concentrations in pore water. Furthermore, the inexpensive material, ease of construction, minimal disturbance to the sediment and applicability for wetland sediments are advantages of the collector presented here compared with traditional pore water sampling techniques.

  15. Determination of pyridine in soil and water samples of a polluted area

    NARCIS (Netherlands)

    Peters, R.J.B.; Renesse van Duivenbode, J.A.D. van

    1994-01-01

    A method for the analyses of pyridine in environmental samples is described. For soil samples a distillation procedure followed by an extraction, an acidic extraction or a Soxhlet extraction can be used. For water samples a distillation procedure followed by extraction can be employed. Deuterated

  16. Measurement of radon concentration in some water samples belonging to some adjoining areas of Pathankot, Punjab

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Ajay, E-mail: ajay782@rediffmail.com; Sharma, Sumit, E-mail: sumitshrm210@gmail.com [Post Graduate Department of Physics, DAV College, Amritsar-143001 (India)

    2015-08-28

    The study of radon concentration was measured in some areas of Pathankot district, Punjab, India, from the health hazard point of view due to radon. The exposure to radon through drinking water is largely by inhalation and ingestion. RAD 7, an electronic solid state silicon detector (Durridgeco., USA) was used to measure the radon concentration in drinking water samples of the study area. The recorded values of radon concentration in these water samples are below the recommended limit by UNSCEAR and European commission. The recommended limit of radon concentration in water samples is 4 to 40 Bq/l given by UNSCEAR [1] and European commission has recommended the safe limit for radon concentration in water sample is 100 Bq/l [2].

  17. Pesticide residues analysis in water samples of Nagarpur and Saturia Upazila, Bangladesh

    Science.gov (United States)

    Hasanuzzaman, M.; Rahman, M. A.; Islam, M. S.; Salam, M. A.; Nabi, M. R.

    2018-03-01

    Pesticides used to protect the crops from pest attack in the agricultural fields pose harmful effect to the non-target organisms such as human and many other aquatic and terrestrial organisms either directly or indirectly through food chain. The present study was conducted to monitor a total of seven pesticide residues under organochlorine, organophosphorus and carbamate pesticides in three different sources of pond water, paddy field water and tube-well water from Nagarpur Upazila and paddy field water in the company of Dhaleshwari and Gazikhali river water from Saturia Upazila, Bangladesh. A total of 40 water samples were analyzed using high-performance liquid chromatography equipped with ultraviolet detector. Among the organophosphorus pesticides, diazinon was detected in eight water samples at a concentration ranging from 4.11 to 257.91 μg/l whereas, malathion was detected only in one water sample at a concentration of 84.64 μg/l and chlorpyrifos pesticide was also detected only in one water sample and the concentration was 37.3 μg/l. Trace amount of carbaryl was identified but it was below the detection limit. None of the tested water samples was found to be contaminated with DDT or its metabolites (DDE and DDD). The water samples contaminated with the suspected pesticides were above the acceptable limit except for the fish pond samples of Sahabatpur and Dubaria union. To control the misuse of pesticides and to reduce the possible health risk, appropriate control systems of pests such as integrated pest management system should be implemented immediately by the authorities of the country.

  18. A QUANTITATIVE EVALUATION OF THE WATER DISTRIBUTION IN A SOIL SAMPLE USING NEUTRON IMAGING

    Directory of Open Access Journals (Sweden)

    Jan Šácha

    2016-10-01

    Full Text Available This paper presents an empirical method by Kang et al. recently proposed for correcting two-dimensional neutron radiography for water quantification in soil. The method was tested on data from neutron imaging of the water infiltration in a soil sample. The raw data were affected by neutron scattering and by beam hardening artefacts. Two strategies for identifying the correction parameters are proposed in this paper. The method has been further developed for the case of three-dimensional neutron tomography. In a related experiment, neutron imaging is used to record ponded-infiltration experiments in two artificial soil samples. Radiograms, i.e., two-dimensional projections of the sample, were acquired during infiltration. A calculation was made of the amount of water and its distribution within the radiograms, in the form of two-dimensional water thickness maps. Tomograms were reconstructed from the corrected and uncorrected water thickness maps to obtain the 3D spatial distribution of the water content within the sample. Without the correction, the beam hardening and the scattering effects overestimated the water content values close to the perimeter of the sample, and at the same time underestimated the values close to the centre of the sample. The total water content of the entire sample was the same in both cases. The empirical correction method presented in this study is a relatively accurate, rapid and simple way to obtain the quantitatively determined water content from two-dimensional and three-dimensional neutron images. However, an independent method for measuring the total water volume in the sample is needed in order to identify the correction parameters.

  19. Presence of pesticide residues in water, sediment and biological samples taken from aquatic environments in Honduras

    International Nuclear Information System (INIS)

    Meyer, D.E.

    1999-01-01

    The objective of this study was to detect the presence of persistent pesticides in water, sediment and biological samples taken from aquatic environments in Honduras during the period 1995-98. Additionally, the LC 50 for 2 fungicides and 2 insecticides on post-larval Penaeus vannamei was determined in static water bioassays. A total of 80 water samples, 16 sediment samples and 7 biological samples (fish muscle tissue) were analyzed for detection of organochlorine and organophosphate pesticide residues. The results of sample analyses indicate a widespread contamination of Honduran continental and coastal waters with organochlorine pesticides. Most detections were of low ( 50 values and were therefore found to be much more toxic to the post-larval shrimp than the fungicides tridemorph and propiconazole. (author)

  20. First Total Reflection X-Ray Fluorescence round-robin test of water samples: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Borgese, Laura; Bilo, Fabjola [Chemistry for Technologies Laboratory, University of Brescia, Brescia (Italy); Tsuji, Kouichi [Graduate School of Engineering, Osaka City University, Osaka (Japan); Fernández-Ruiz, Ramón [Servicio Interdepartamental de Investigación (SIdI), Laboratorio de TXRF, Universidad Autónoma de Madrid, Madrid (Spain); Margui, Eva [Department of Chemistry, University of Girona, Girona (Spain); Streli, Christina [TU Wien, Atominstitut,Radiation Physics, Vienna (Austria); Pepponi, Giancarlo [Fondazione Bruno Kessler, Povo, Trento (Italy); Stosnach, Hagen [Bruker Nano GmbH, Berlin (Germany); Yamada, Takashi [Rigaku Corporation, Takatsuki, Osaka (Japan); Vandenabeele, Peter [Department of Archaeology, Ghent University, Ghent (Belgium); Maina, David M.; Gatari, Michael [Institute of Nuclear Science and Technology, University of Nairobi, Nairobi (Kenya); Shepherd, Keith D.; Towett, Erick K. [World Agroforestry Centre (ICRAF), Nairobi (Kenya); Bennun, Leonardo [Laboratorio de Física Aplicada, Departamento de Física, Universidad de Concepción (Chile); Custo, Graciela; Vasquez, Cristina [Gerencia Química, Laboratorio B025, Centro Atómico Constituyentes, San Martín (Argentina); Depero, Laura E., E-mail: laura.depero@unibs.it [Chemistry for Technologies Laboratory, University of Brescia, Brescia (Italy)

    2014-11-01

    Total Reflection X-Ray Fluorescence (TXRF) is a mature technique to evaluate quantitatively the elemental composition of liquid samples deposited on clean and well polished reflectors. In this paper the results of the first worldwide TXRF round-robin test of water samples, involving 18 laboratories in 10 countries are presented and discussed. The test was performed within the framework of the VAMAS project, interlaboratory comparison of TXRF spectroscopy for environmental analysis, whose aim is to develop guidelines and a standard methodology for biological and environmental analysis by means of the TXRF analytical technique. - Highlights: • The discussion of the first worldwide TXRF round-robin test of water samples (18 laboratories of 10 countries) is reported. • Drinking, waste, and desalinated water samples were tested. • Data dispersion sources were identified: sample concentration, preparation, fitting procedure, and quantification. • The protocol for TXRF analysis of drinking water is proposed.

  1. Semi-nested polymerase chain reaction for detection of toxigenic Vibrio cholerae from environmental water samples.

    Science.gov (United States)

    Goel, Ajay Kumar; Bhadauria, Shweta; Kumar, Pramod; Kamboj, Dev V; Singh, Lokendra

    2007-09-01

    A rapid and sensitive direct cell semi-nested PCR assay was developed for the detection of viable toxigenic V. cholerae in environmental water samples. The semi-nested PCR assay amplified cholera toxin (ctxA2B) gene present in the toxigenic V. cholerae. The detection sensitivity of direct cell semi-nested PCR was 2 × 10(3) CFU of V. cholerae whereas direct cell single-step PCR could detect 2 × 10(4) CFU of V. cholerae. The performance of the assay was evaluated using environmental water samples after spiking with known number of Vibrio cholerae O1. The spiked water samples were filtered through a 0.22 micrometer membrane and the bacteria retained on filters were enriched in alkaline peptone water and then used directly in the PCR assay. The semi-nested PCR procedure coupled with enrichment could detect less than 1 CFU/ml in ground water and sea water whereas 2 CFU/ml and 20 CFU/ml could be detected in pond water and tap water, respectively. The proposed method is simple, faster than the conventional detection assays and can be used for screening of drinking water or environmental water samples for the presence of toxigenic V. cholerae.

  2. Estimation of uranium in drinking water samples collected from different locations across Tarapur, India

    International Nuclear Information System (INIS)

    Dusane, C.B.; Maity, Sukanta; Sahu, S.K.; Pandit, G.G.

    2015-01-01

    In this study, drinking water samples were collected from different locations across Tarapur, India for screening uranium contents. Uranium concentrations were determined by differential pulse adsorptive stripping voltammetry (DPASV). Uranium concentration in water samples varied in a wide range from 0.6-7.9 μg L -1 . Results were compared with the international water quality guidelines World Health Organization (WHO, 2011) and were found within the permissible limit. Results were also compared with the safe limit values for drinking water recommended by national organization like Atomic Energy Regulatory Board (AERB). (author)

  3. 2nd interlaboratory comparison for deuterium and oxygen-18 analysis of water samples

    International Nuclear Information System (INIS)

    Lippmann, J.; Groening, M.

    1999-01-01

    The IAEA Isotope Hydrology Laboratory organised in 1998/99 the 2nd interlaboratory comparison test for the analyses of hydrogen and oxygen isotope composition of water. The test was open to all laboratories engaged in isotope analyses of water samples world-wide. The main objective of this exercise was to help the laboratories to assess their precision and accuracy for the range of δ 18 O and δ 2 H values normally observed in meteoric waters. More than 115 laboratories from 43 countries indicated their willingness to participate in the exercise and received four water samples (OH-1 to OH-4) for analysis

  4. Estimating an appropriate sampling frequency for monitoring ground water well contamination

    International Nuclear Information System (INIS)

    Tuckfield, R.C.

    1994-01-01

    Nearly 1,500 ground water wells at the Savannah River Site (SRS) are sampled quarterly to monitor contamination by radionuclides and other hazardous constituents from nearby waste sites. Some 10,000 water samples were collected in 1993 at a laboratory analysis cost of $10,000,000. No widely accepted statistical method has been developed, to date, for estimating a technically defensible ground water sampling frequency consistent and compliant with federal regulations. Such a method is presented here based on the concept of statistical independence among successively measured contaminant concentrations in time

  5. Multiport well design for sampling of ground water at closely spaced vertical intervals

    Science.gov (United States)

    Delin, G.N.; Landon, M.K.

    1996-01-01

    Detailed vertical sampling is useful in aquifers where vertical mixing is limited and steep vertical gradients in chemical concentrations are expected. Samples can be collected at closely spaced vertical intervals from nested wells with short screened intervals. However, this approach may not be appropriate in all situations. An easy-to-construct and easy-to-install multiport sampling well to collect ground-water samples from closely spaced vertical intervals was developed and tested. The multiport sampling well was designed to sample ground water from surficial sand-and-gravel aquifers. The device consists of multiple stainless-steel tubes within a polyvinyl chloride (PVC) protective casing. The tubes protrude through the wall of the PVC casing at the desired sampling depths. A peristaltic pump is used to collect ground-water samples from the sampling ports. The difference in hydraulic head between any two sampling ports can be measured with a vacuum pump and a modified manometer. The usefulness and versatility of this multiport well design was demonstrated at an agricultural research site near Princeton, Minnesota where sampling ports were installed to a maximum depth of about 12 m below land surface. Tracer experiments were conducted using potassium bromide to document the degree to which short-circuiting occurred between sampling ports. Samples were successfully collected for analysis of major cations and anions, nutrients, selected herbicides, isotopes, dissolved gases, and chlorofluorcarbon concentrations.

  6. Monitoring the aftermath of Flint drinking water contamination crisis: Another case of sampling bias?

    Science.gov (United States)

    Goovaerts, Pierre

    2017-07-15

    The delay in reporting high levels of lead in Flint drinking water, following the city's switch to the Flint River as its water supply, was partially caused by the biased selection of sampling sites away from the lead pipe network. Since Flint returned to its pre-crisis source of drinking water, the State has been monitoring water lead levels (WLL) at selected "sentinel" sites. In a first phase that lasted two months, 739 residences were sampled, most of them bi-weekly, to determine the general health of the distribution system and to track temporal changes in lead levels. During the same period, water samples were also collected through a voluntary program whereby concerned citizens received free testing kits and conducted sampling on their own. State officials relied on the former data to demonstrate the steady improvement in water quality. A recent analysis of data collected by voluntary sampling revealed, however, an opposite trend with lead levels increasing over time. This paper looks at potential sampling bias to explain such differences. Although houses with higher WLL were more likely to be sampled repeatedly, voluntary sampling turned out to reproduce fairly well the main characteristics (i.e. presence of lead service lines (LSL), construction year) of Flint housing stock. State-controlled sampling was less representative; e.g., sentinel sites with LSL were mostly built between 1935 and 1950 in lower poverty areas, which might hamper our ability to disentangle the effects of LSL and premise plumbing (lead fixtures and pipes present within old houses) on WLL. Also, there was no sentinel site with LSL in two of the most impoverished wards, including where the percentage of children with elevated blood lead levels tripled following the switch in water supply. Correcting for sampling bias narrowed the gap between sampling programs, yet overall temporal trends are still opposite. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Design, analysis, and interpretation of field quality-control data for water-sampling projects

    Science.gov (United States)

    Mueller, David K.; Schertz, Terry L.; Martin, Jeffrey D.; Sandstrom, Mark W.

    2015-01-01

    The process of obtaining and analyzing water samples from the environment includes a number of steps that can affect the reported result. The equipment used to collect and filter samples, the bottles used for specific subsamples, any added preservatives, sample storage in the field, and shipment to the laboratory have the potential to affect how accurately samples represent the environment from which they were collected. During the early 1990s, the U.S. Geological Survey implemented policies to include the routine collection of quality-control samples in order to evaluate these effects and to ensure that water-quality data were adequately representing environmental conditions. Since that time, the U.S. Geological Survey Office of Water Quality has provided training in how to design effective field quality-control sampling programs and how to evaluate the resultant quality-control data. This report documents that training material and provides a reference for methods used to analyze quality-control data.

  8. Ionizing radiation as optimization method for aluminum detection from drinking water samples

    International Nuclear Information System (INIS)

    Bazante-Yamguish, Renata; Geraldo, Aurea Beatriz C.; Moura, Eduardo; Manzoli, Jose Eduardo

    2013-01-01

    The presence of organic compounds in water samples is often responsible for metal complexation; depending on the analytic method, the organic fraction may dissemble the evaluation of the real values of metal concentration. Pre-treatment of the samples is advised when organic compounds are interfering agents, and thus sample mineralization may be accomplished by several chemical and/or physical methods. Here, the ionizing radiation was used as an advanced oxidation process (AOP), for sample pre-treatment before the analytic determination of total and dissolved aluminum by ICP-OES in drinking water samples from wells and spring source located at Billings dam region. Before irradiation, the spring source and wells' samples showed aluminum levels of 0.020 mg/l and 0.2 mg/l respectively; after irradiation, both samples showed a 8-fold increase of aluminum concentration. These results are discussed considering other physical and chemical parameters and peculiarities of sample sources. (author)

  9. Arsenic-related water quality with depth and water quality of well-head samples from production wells, Oklahoma, 2008

    Science.gov (United States)

    Becker, Carol J.; Smith, S. Jerrod; Greer, James R.; Smith, Kevin A.

    2010-01-01

    The U.S. Geological Survey well profiler was used to describe arsenic-related water quality with well depth and identify zones yielding water with high arsenic concentrations in two production wells in central and western Oklahoma that yield water from the Permian-aged Garber-Wellington and Rush Springs aquifers, respectively. In addition, well-head samples were collected from 12 production wells yielding water with historically large concentrations of arsenic (greater than 10 micrograms per liter) from the Garber-Wellington aquifer, Rush Springs aquifer, and two minor aquifers: the Arbuckle-Timbered Hills aquifer in southern Oklahoma and a Permian-aged undefined aquifer in north-central Oklahoma. Three depth-dependent samples from a production well in the Rush Springs aquifer had similar water-quality characteristics to the well-head sample and did not show any substantial changes with depth. However, slightly larger arsenic concentrations in the two deepest depth-dependent samples indicate the zones yielding noncompliant arsenic concentrations are below the shallowest sampled depth. Five depth-dependent samples from a production well in the Garber-Wellington aquifer showed increases in arsenic concentrations with depth. Well-bore travel-time information and water-quality data from depth-dependent and well-head samples showed that most arsenic contaminated water (about 63 percent) was entering the borehole from perforations adjacent to or below the shroud that overlaid the pump. Arsenic concentrations ranged from 10.4 to 124 micrograms per liter in 11 of the 12 production wells sampled at the well head, exceeding the maximum contaminant level of 10 micrograms per liter for drinking water. pH values of the 12 well-head samples ranged from 6.9 to 9. Seven production wells in the Garber-Wellington aquifer had the largest arsenic concentrations ranging from 18.5 to 124 micrograms per liter. Large arsenic concentrations (10.4-18.5) and near neutral to slightly alkaline

  10. Identification and quantification of pesticide residues in water samples of Dhamrai Upazila, Bangladesh

    Science.gov (United States)

    Hasanuzzaman, M.; Rahman, M. A.; Salam, M. A.

    2017-10-01

    Being agricultural country, different types of pesticides are widely used in Bangladesh to prevent the crop losses due to pest attack which are ultimately drain to the water bodies. The present study was conducted to identify and quantify the organochlorine (DDT, DDE and DDD), organophosphorus (malathion, diazinon and chloropyrifos) and carbamate (carbaryl) residues in water samples of different sources from Dhamrai upazila of Bangladesh using high performance liquid chromatography (HPLC) equipped with ultra violate (UV) detector. Thirty water samples from fish pond, cultivated land and tube-well were collected in winter season to analyze the pesticide residues. Among the organophosphorus pesticides, malathion was present in seven water samples ranging from 42.58 to 922.8 μg/L, whereas diazinon was detected in water sample-8 (WS-8) and the concentration was 31.5 μg/L. None of the tested water samples was found to be contaminated with chlorpyrifos, carbaryl or DDT and its metabolites (DDE and DDD). Except for a tube-well water sample, concentrations of the detected residues are above the acceptable limit for human body as assigned by different organizations. To avoid the possible health hazards, the indiscriminate application of pesticides should be restricted and various substitute products like bio-pesticide should be introduced in a broad scale as soon as possible.

  11. Molecular identification of Blastocystis sp. subtypes in water samples collected from Black sea, Turkey.

    Science.gov (United States)

    Koloren, Zeynep; Gulabi, Berivan Basak; Karanis, Panagiotis

    2018-04-01

    The aim of this study was to identify the subtypes of Blastocystis sp. and complete a phylogenetic analysis of 268 water samples that were collected from the Samsun, Amasya and Sinop Provinces of the Black Sea in Turkey, between the years 2011 and 2014. Blastocystis sp. was investigated in 48 uncultured sea water samples that were collected from 4 sites within the Sinop Province. A total of 100 river water samples were collected from 37 sites in the Samsun Province and 120 river water samples were collected from 10 sampling sites within the Amasya Province. The small subunit (SSU) rDNA gene Polymerase chain reaction (PCR) were performed for the detection of Blastocytis sp. and the PCR-positive samples were sequenced. Subsequently, the (SSU) rDNA sequences were aligned by Bioedit and phylogenetic trees were constructed for Blastocystis with reference to the genotypes from GenBank. Blastocystis sp. were found in 3 out of the 75 (4%) river water samples that were collected from the Samsun Province. Six of the 120 (5%) river water samples and 1 out of the 48 (2%) seawater samples were positive for Blastocystis in the Amasya and Sinop Provinces. There were two different subtypes (ST; 1 and 3) found from sequencing all of the samples from the investigated sites. Two and one PCR products were found to be positive for ST1 and ST3 from the different samples collected within the Samsun Province. Two and 4 PCR products from the Amasya Province were ST1 and ST3, respectively and only one sample from the Sinop Province was found to be positive for ST1. This is the first report to identify and report the occurrence of Blastocystis subtypes within the Black Sea of Turkey. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. “Nanofiltration” Enabled by Super-Absorbent Polymer Beads for Concentrating Microorganisms in Water Samples

    Science.gov (United States)

    Xie, Xing; Bahnemann, Janina; Wang, Siwen; Yang, Yang; Hoffmann, Michael R.

    2016-02-01

    Detection and quantification of pathogens in water is critical for the protection of human health and for drinking water safety and security. When the pathogen concentrations are low, large sample volumes (several liters) are needed to achieve reliable quantitative results. However, most microbial identification methods utilize relatively small sample volumes. As a consequence, a concentration step is often required to detect pathogens in natural waters. Herein, we introduce a novel water sample concentration method based on superabsorbent polymer (SAP) beads. When SAP beads swell with water, small molecules can be sorbed within the beads, but larger particles are excluded and, thus, concentrated in the residual non-sorbed water. To illustrate this approach, millimeter-sized poly(acrylamide-co-itaconic acid) (P(AM-co-IA)) beads are synthesized and successfully applied to concentrate water samples containing two model microorganisms: Escherichia coli and bacteriophage MS2. Experimental results indicate that the size of the water channel within water swollen P(AM-co-IA) hydrogel beads is on the order of several nanometers. The millimeter size coupled with a negative surface charge of the beads are shown to be critical in order to achieve high levels of concentration. This new concentration procedure is very fast, effective, scalable, and low-cost with no need for complex instrumentation.

  13. "Nanofiltration" Enabled by Super-Absorbent Polymer Beads for Concentrating Microorganisms in Water Samples.

    Science.gov (United States)

    Xie, Xing; Bahnemann, Janina; Wang, Siwen; Yang, Yang; Hoffmann, Michael R

    2016-02-15

    Detection and quantification of pathogens in water is critical for the protection of human health and for drinking water safety and security. When the pathogen concentrations are low, large sample volumes (several liters) are needed to achieve reliable quantitative results. However, most microbial identification methods utilize relatively small sample volumes. As a consequence, a concentration step is often required to detect pathogens in natural waters. Herein, we introduce a novel water sample concentration method based on superabsorbent polymer (SAP) beads. When SAP beads swell with water, small molecules can be sorbed within the beads, but larger particles are excluded and, thus, concentrated in the residual non-sorbed water. To illustrate this approach, millimeter-sized poly(acrylamide-co-itaconic acid) (P(AM-co-IA)) beads are synthesized and successfully applied to concentrate water samples containing two model microorganisms: Escherichia coli and bacteriophage MS2. Experimental results indicate that the size of the water channel within water swollen P(AM-co-IA) hydrogel beads is on the order of several nanometers. The millimeter size coupled with a negative surface charge of the beads are shown to be critical in order to achieve high levels of concentration. This new concentration procedure is very fast, effective, scalable, and low-cost with no need for complex instrumentation.

  14. Genotypic characterization of Cryptosporidium hominis from water samples in Sao Paulo, Brazil.

    Science.gov (United States)

    Araújo, Ronalda S; Dropa, Milena; Fernandes, Licia N; Carvalho, Terezinha T; Sato, Maria Inês Z; Soares, Rodrigo M; Matté, Glavur R; Matté, Maria Helena

    2011-11-01

    The protozoan parasite Cryptosporidium has emerged as one of the most important water contaminants, causing waterborne outbreaks of diarrheal diseases worldwide. The small size of oocysts under the microscope and the possibility of changes in characteristics of oocysts, mainly in environmental samples, make the taxonomy of the genus difficult if morphologic characteristics are considered. This limitation encouraged the application of molecular methods to identify this microorganism. The aim of this study was to detect and identify by nested-polymerase chain reaction oocysts of Cryptosporidium present in water samples in the state of São Paulo, Brazil. Water samples were concentrated through a membrane filter, DNA was extracted by using a standard technique, and both amplification reactions used forward and reverse oligonucleotides that were complementary to Cryptosporidium 18S ribosomal RNA gene sequences. Thirty water samples from different sites of collection in the state of São Paulo were evaluated. Cryptosporidium oocysts were detected in 30% of the samples. By genoptyping, C. hominis and Cryptosporidium sp. were identified in recreational water and C. meleagridis was identified in surface water samples. This is the first report of C. hominis in environmental samples in Brazil. Although identification of Cryptosporidium is still a difficult task, molecular methods are essential for specific identification and are a helpful tool to aid to understand the epidemiology of this parasite in Brazil.

  15. A clinical case of single-stage correction of penetration combined orofacial defect with two microsurgical autografts

    Directory of Open Access Journals (Sweden)

    A. D. Kaprin

    2015-01-01

    Full Text Available After surgical treatment for locally advanced oral tumors with resection of soft tissues, mucosal membrane, and facial skeletal structures, there are penetration combined defects, removal of which is a challenge for reconstructive surgeons. Mandibular repair is one of the problems in the correction of combined oral defects. Surgeons use different grafts to remove mandibular defects. One-flap transplantation does not always solve all reconstruction problems and ensure the repair of the mucosal membrane, a soft-tissue component, skin integuments, and facial skeleton.The authors describe a clinical case of successful single-stage correction of penetration combined orofacial defect after resection of the tongue, mouth floor, en bloc resection of the lower jaw and mental soft tissues, bilateral cervical supramyochoroidal lymphadenectomy, stage LCL CM mandibular defect formation after J. Boyd, by using two microsurgical autografts (a peroneal skin-muscle-skin autograft and a radial skin-fascia one in a 39-year-old female patient clinically diagnosed with carcinoma of the left mandibular alveolar ridge mucosa, Stage IVA (T4аN0M0.The Department of Microsurgery, P.A. Herzen Moscow Oncology Research Institute, Ministry of Health of Russia, has gained experience in comprehensively correcting extensive combined maxillofacial defects with two or more grafts in 27 patients who underwent autografting with a total of 73 flaps. The most functionally incapacitating and life-incompatible defect was removed at Stage 1 of reconstructive treatment. Delayed reconstruction was made after a complex of specialized antitumor therapy and assessment of treatment results in the absence of progressive growth. A great problem during multi-stage defect correction is presented by the lack of recipient vessels after cervical lymphadenectomy, the presence of soft tissue scar changes, trismus, temporomandibular joint ankylosis, contractures and displacement of the edges of the

  16. A new dissolved gas sampling method from primary water of the Paks Nuclear Power Plant, Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Papp, L., E-mail: papp.laszlo@atomki.mta.hu [Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen (Hungary); Isotoptech Co. Ltd., Debrecen (Hungary); Palcsu, L. [Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen (Hungary); Veres, M. [Isotoptech Co. Ltd., Debrecen (Hungary); Pintér, T. [Paks Nuclear Power Plant, Paks (Hungary)

    2016-04-15

    Highlights: • We constructed and applied a lightweight portable dissolved gas sampling device. • A membrane contactor has been used to sample the dissolved gases from the water. • Gas compound and gamma spectrometric measurements were done from the samples. - Abstract: This article describes a novel sampling method for dissolved gases from radioactive waters. The major aim was to build a portable, lightweight sampling device in which the gas sample container is not in contact with the water itself. Therefore, a membrane contactor was used to take representative dissolved gas samples from the water of spent fuel pools. Quadrupole mass spectrometric and gamma spectrometric measurements were made from the samples to determine the gas composition and to detect any radioactive gas of fission origin. The paper describes (i) the construction of the sampler in general, (ii) the operation of the sampling unit and (iii) the measurement results of the first samples and the interpretation of the data. Both small and large fluctuations were able to be detected when the freshly spent fuel rods were put into the spent fuel pool or when the head valves of the toques of the fuel rods were replaced. In the investigated period (2013–2014), the main gas composition did not show large fluctuations, it was close to the composition of dissolved air. However, the activity concentration of {sup 85}Kr varied in a broad range (0.001–100 kBq/l).

  17. Genotoxicity assessment of water sampled from R-11 reservoir by means of allium test

    Energy Technology Data Exchange (ETDEWEB)

    Bukatich, E.; Pryakhin, E. [Urals Research Center for Radiation Medicine (Russian Federation); Geraskin, S. [Russian Institute of Agricultural Radiology and Agroecology (Russian Federation)

    2014-07-01

    The Mayak PA was the first enterprise for the production of weapon-grade plutonium in Russia and it incorporates uranium-graphite reactors for plutonium production and radiochemical facilities for its separation. Radiochemical processing resulted in huge volumes of liquid radioactive wastes of different specific activities. To reduce the radionuclides release into the environment, a system of bypasses and ponds (the Techa Cascade Reservoirs system) to store low-activity liquid wastes has been constructed in the upper reaches of the Techa River. Currently, industrial reservoirs of Mayak PA contain over 350 million m{sup 3} of low-level radioactive liquid wastes with total activity over 7.4 x 10{sup 15} Bq. Reservoir R-11 is the final reservoir in the Techa Cascade Reservoirs system. The average specific activity of main radionuclides in the water of R-11 are: {sup 90}Sr - 1.4x10{sup 3} Bq/l; {sup 137}Cs - 3 Bq/l; {sup 3}H - 7x10{sup 2} Bq/l; α-emitting radionuclides - 2.6 x 10{sup -1} Bq/l. In our study the Allium-test was employed to estimate reservoir R-11 water genotoxic effects. In 2012, 3 water samples were collected in different parts of reservoir R-11. Water samples from the Shershnevskoye reservoir (artificial reservoir on the Miass River designed for Chelyabinsk city water supply) were used as natural control. Samples of distilled and bottled water were used as an additional laboratory control. The common onion, Allium cepa L. (Stuttgarter Riesen) was used. Healthy equal-sized bulbs were soaked for 24 hours at +4±2 deg. C to synchronize cell division. The bulbs were maintained in distilled water at +23 deg. C until roots have grown up to 2±1 mm length and then plunged into water samples. Control samples remained in distilled and bottled water as well as in water samples from the Shershnevskoye reservoir (natural control). Roots of the 18±3 mm length were randomly sampled and fixed in an alcohol/acetic acid mixture. For microscopic analysis, squashed

  18. Instrumental neutron activation analysis data for cloud-water particulate samples, Mount Bamboo, Taiwan

    Science.gov (United States)

    Lin, Neng-Huei; Sheu, Guey-Rong; Wetherbee, Gregory A.; Debey, Timothy M.

    2013-01-01

    Cloud water was sampled on Mount Bamboo in northern Taiwan during March 22-24, 2002. Cloud-water samples were filtered using 0.45-micron filters to remove particulate material from the water samples. Filtered particulates were analyzed by instrumental neutron activation analysis (INAA) at the U.S. Geological Survey National Reactor Facility in Denver, Colorado, in February 2012. INAA elemental composition data for the particulate materials are presented. These data complement analyses of the aqueous portion of the cloud-water samples, which were performed earlier by the Department of Atmospheric Sciences, National Central University, Taiwan. The data are intended for evaluation of atmospheric transport processes and air-pollution sources in Southeast Asia.

  19. Exploring the Legionella pneumophila positivity rate in hotel water samples from Antalya, Turkey.

    Science.gov (United States)

    Sepin Özen, Nevgün; Tuğlu Ataman, Şenay; Emek, Mestan

    2017-05-01

    The genus Legionella is a fastidious Gram-negative bacteria widely distributed in natural waters and man made water supply systems. Legionella pneumophila is the aetiological agent of approximately 90% of reported Legionellosis cases, and serogroup 1 is the most frequent cause of infections. Legionnaires' disease is often associated with travel and continues to be a public health concern at present. The correct water management quality practices and rapid methods for analyzing Legionella species in environmental water is a key point for the prevention of Legionnaires' disease outbreaks. This study aimed to evaluate the positivity rates and serotyping of Legionella species from water samples in the region of Antalya, Turkey, which is an important tourism center. During January-December 2010, a total of 1403 samples of water that were collected from various hotels (n = 56) located in Antalya were investigated for Legionella pneumophila. All samples were screened for L. pneumophila by culture method according to "ISO 11731-2" criteria. The culture positive Legionella strains were serologically identified by latex agglutination test. A total of 142 Legionella pneumophila isolates were recovered from 21 (37.5%) of 56 hotels. The total frequency of L. pneumophila isolation from water samples was found as 10.1%. Serological typing of 142 Legionella isolates by latex agglutination test revealed that strains belonging to L. pneumophila serogroups 2-14 predominated in the examined samples (85%), while strains of L. pneumophila serogroup 1 were less numerous (15%). According to our knowledge, our study with the greatest number of water samples from Turkey demonstrates that L. pneumophila serogroups 2-14 is the most common isolate. Rapid isolation of L. pneumophila from environmental water samples is essential for the investigation of travel related outbreaks and the possible resources. Further studies are needed to have epidemiological data and to determine the types of L

  20. Microbiology of the surface water samples in the high background radiation areas of Ramsar, Iran

    International Nuclear Information System (INIS)

    Motamedifar, Mohammad; Zamani, Khosrow; Sedigh, Hadi; Mortazavi, Seyed Mohammad Javad; Taeb, Shahram; Haghani, M.; Mortazavi, Seyed Ali Reza; Soofi, Amir

    2014-01-01

    Residents of high background radiation areas of Ramsar have lived in these areas for many generations and received radiation doses much higher than the dose limit recommended by ICRP for radiation workers. The radioactivity of the high background radiation areas of Ramsar is reported to be due to 226 Ra and its decay products, which have been brought to the surface by the waters of hot springs. Over the past years the department has focused on different aspects of the health effects of the elevated levels of natural radiation in Ramsar. This study was aimed to perform a preliminary investigation on the bioeffects of exposure to elevated levels of natural radiation on the microbiology of surface water samples. Water samples were collected from surface water streams in Talesh Mahalleh district, Ramsar as well as a nearby area with normal levels of background radiation. Only two strains of bacteria, that is, Providencia stuartii and Shimwellia blattae, could be isolated from the water samples collected from high background radiation areas, while seven strains (Escherichia coli, Enterobacter asburiae, Klebsiella pneumoniae, Shigella dysenteriae, Buttiauxella agerstis, Tatumella punctuata and Raoultella ornithinolytica) were isolated from the water samples collected from normal background radiation areas. All the bacteria isolated from water samples of high and normal background radiation areas were sensitive to ultraviolet radiation, heat, betadine, alcohol, and deconex. Although other investigators have reported that bacteria isolated from hot springs show radioresistance, the results reported here do not reveal any adaptive response. (author)

  1. Supplement to the UMTRA project water sampling and analysis plan, Slick Rock, Colorado

    International Nuclear Information System (INIS)

    1995-09-01

    The water sampling and analysis plan (WSAP) provides the regulatory and technical basis for ground water and surface water sampling at the Uranium Mill Tailings Remedial Action (UMTRA) Project Union Carbide (UC) and North Continent (NC) processing sites and the Burro Canyon disposal site near Slick Rock, Colorado. The initial WSAP was finalized in August 1994 and will be completely revised in accordance with the WSAP guidance document (DOE, 1995) in late 1996. This version supplements the initial WSAP, reflects only minor changes in sampling that occurred in 1995, covers sampling scheduled for early 1996, and provides a preliminary projection of the next 5 years of sampling and monitoring activities. Once surface remedial action is completed at the former processing sites, additional and more detailed hydrogeologic characterization may be needed to develop the Ground Water Program conceptual ground water model and proposed compliance strategy. In addition, background ground water quality needs to be clearly defined to ensure that the baseline risk assessment accurately estimated risks from the contaminants of potential concern in contaminated ground water at the UC and NC sites

  2. Atrazine, triketone herbicides, and their degradation products in sediment, soil and surface water samples in Poland.

    Science.gov (United States)

    Barchanska, Hanna; Sajdak, Marcin; Szczypka, Kornelia; Swientek, Angelika; Tworek, Martyna; Kurek, Magdalena

    2017-01-01

    The aim of this study was to monitor the sediment, soil and surface water contamination with selected popular triketone herbicides (mesotrione (MES) and sulcotrione(SUL)), atrazine (ATR) classified as a possible carcinogen and endocrine disrupting chemical, as well as their degradation products, in Silesia (Poland). Seventeen sediment samples, 24 soil samples, and 64 surface water samples collected in 2014 were studied. After solid-liquid extraction (SLE) and solid phase extraction (SPE), analytes were determined by high-performance liquid chromatography (HPLC) with diode array detection (DAD). Ten years after the withdrawal from the use, ATR was not detected in any of the collected samples; however, its degradation products are still present in 41 % of sediment, 71 % of soil, and 8 % of surface water samples. SUL was determined in 85 % of soil samples; its degradation product (2-chloro-4-(methylosulfonyl) benzoic acid (CMBA)) was present in 43 % of soil samples. In 17 % of sediment samples, CMBA was detected. Triketones were detected occasionally in surface water samples. The chemometric analysis (clustering analysis (CA), single-factor analysis of variance (ANOVA), N-Way ANOVA) was applied to find relations between selected soil and sediment parameters and herbicides concentration. In neither of the studied cases a statistically significant relationship between the concentrations of examined herbicides, their degradation products and soil parameters (organic carbon (OC), pH) was observed.

  3. Soil and Water – What is Detectable through Microbiological Sample Preparation Techniques

    Science.gov (United States)

    The concerns of a potential terrorist’s use of biological agents in soil and ground water are articulated by comparisons to major illnesses in this Country involving contaminated drinking water sources. Objectives are focused on the importance of sample preparation in the rapid, ...

  4. Stable isotope ratio measurements on highly enriched water samples by means of laser spectrometry

    NARCIS (Netherlands)

    van Trigt, R; Kerstel, E.R.T.; Visser, GH; Meijer, H.A.J.

    2001-01-01

    We demonstrate the feasibility of using laser spectrometry (LS) to analyze isotopically highly enriched water samples (i.e., delta H-2 less than or equal to 15000 parts per thousand, delta O-18 less than or equal to 1200 parts per thousand), as often used in the biomedical doubly labeled water (DLW)

  5. Natural radioactivity in various water samples and radiation dose estimations in Bolu province, Turkey.

    Science.gov (United States)

    Gorur, F Korkmaz; Camgoz, H

    2014-10-01

    The level of natural radioactivity for Bolu province of north-western Turkey was assessed in this study. There is no information about radioactivity measurement reported in water samples in the Bolu province so far. For this reason, gross α and β activities of 55 different water samples collected from tap, spring, mineral, river and lake waters in Bolu were determined. The mean activity concentrations were 68.11 mBq L(-1), 169.44 mBq L(-1) for gross α and β in tap water. For all samples the gross β activity is always higher than the gross α activity. All value of the gross α were lower than the limit value of 500 mBq L(-1) while two spring and one mineral water samples were found to have gross β activity concentrations of greater than 1000 mBq L(-1). The associated age-dependent dose from all water ingestion in Bolu was estimated. The total dose for adults had an average value exceeds the WHO recommended limit value. The risk levels from the direct ingestion of the natural radionuclides in tap and mineral water in Bolu were determinated. The mean (210)Po and (228)Ra risk the value of tap and mineral waters slightly exceeds what some consider on acceptable risk of 10(-4) or less. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Guidance document for preparing water sampling and analysis plans for UMTRA Project sites. Revision 1

    International Nuclear Information System (INIS)

    1995-09-01

    A water sampling and analysis plan (WSAP) is prepared for each Uranium Mill Tailings Remedial Action (UMTRA) Project site to provide the rationale for routine ground water sampling at disposal sites and former processing sites. The WSAP identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the routine ground water monitoring stations at each site. This guidance document has been prepared by the Technical Assistance Contractor (TAC) for the US Department of Energy (DOE). Its purpose is to provide a consistent technical approach for sampling and monitoring activities performed under the WSAP and to provide a consistent format for the WSAP documents. It is designed for use by the TAC in preparing WSAPs and by the DOE, US Nuclear Regulatory Commission, state and tribal agencies, other regulatory agencies, and the public in evaluating the content of WSAPS

  7. Introduction of Flame Atomic Absorption Spectrometry (FAAS) For River Water Samples Analysis

    International Nuclear Information System (INIS)

    Shakirah Abd Shukor; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman

    2015-01-01

    Metal contamination in water is a major component in the determination of water quality monitoring. In spite of the viability of several other metal ion analysis techniques for river water, atomic absorption spectroscopy (AAS) method is most commonly used due to the reproducibility results, short analysis time, cost effective, lower level detection and robust. Therefore, this article gives an overview on the principles, instrumentation techniques, sample preparations, instrument calibration and data analysis in a simple manner for beginner. (author)

  8. Geothermal water and gas: collected methods for sampling and analysis. Comment issue. [Compilation of methods

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, J.G.; Serne, R.J.; Shannon, D.W.; Woodruff, E.M.

    1976-08-01

    A collection of methods for sampling and analysis of geothermal fluids and gases is presented. Compilations of analytic options for constituents in water and gases are given. Also, a survey of published methods of laboratory water analysis is included. It is stated that no recommendation of the applicability of the methods to geothermal brines should be assumed since the intent of the table is to encourage and solicit comments and discussion leading to recommended analytical procedures for geothermal waters and research. (WHK)

  9. An Optimized Method for Quantification of Pathogenic Leptospira in Environmental Water Samples

    OpenAIRE

    Riediger, Irina N.; Hoffmaster, Alex R.; Casanovas-Massana, Arnau; Biondo, Alexander W.; Ko, Albert I.; Stoddard, Robyn A.

    2016-01-01

    Leptospirosis is a zoonotic disease usually acquired by contact with water contaminated with urine of infected animals. However, few molecular methods have been used to monitor or quantify pathogenic Leptospira in environmental water samples. Here we optimized a DNA extraction method for the quantification of leptospires using a previously described Taqman-based qPCR method targeting lipL32, a gene unique to and highly conserved in pathogenic Leptospira. QIAamp DNA mini, MO BIO PowerWater DNA...

  10. A Robust High-Performance GPS L1 Receiver with Single-stage Quadrature Redio-Frequency Circuit

    Science.gov (United States)

    Liu, Jianghua; Xu, Weilin; Wan, Qinq; Liu, Tianci

    2018-03-01

    A low power current reuse single-stage quadrature raido-frequency part (SQRF) is proposed for GPS L1 receiver in 180nm CMOS process. The proposed circuit consists of LNA, Mixer, QVCO, is called the QLMV cell. A two blocks stacked topology is adopted in this design. The parallel QVCO and mixer placed on the top forms the upper stacked block, and the LNA placed on the bottom forms the other stacked block. The two blocks share the current and achieve low power performance. To improve the stability, a float current source is proposed. The float current isolated the local oscillation signal and the input RF signal, which bring the whole circuit robust high-performance. The result shows conversion gain is 34 dB, noise figure is three dB, the phase noise is -110 dBc/Hz at 1MHz and IIP3 is -20 dBm. The proposed circuit dissipated 1.7mW with 1 V supply voltage.

  11. Heat transfer and oil flow studies on a single-stage-to-orbit control-configured winged entry vehicle

    Science.gov (United States)

    Helms, V. T., III; Bradley, P. F.

    1984-01-01

    Results are presented for oil flow and phase change paint heat transfer tests conducted on a 0.006 scale model of a proposed single stage to orbit control configured vehicle. The data were taken at angles of attack up to 40 deg at a free stream Mach number of 10 for Reynolds numbers based on model length of 0.5 x 10 to the 6th power, 1.0 x 10 to the 6th power and 2.0 x 10 to the 6th power. The magnitude and distribution of heating are characterized in terms of angle of attack and Reynolds number aided by an analysis of the flow data which are used to suggest the presence of various three dimensional flow structures that produce the observed heating patterns. Of particular interest are streak heating patterns that result in high localized heat transfer rates on the wing windward surface at low to moderate angles of attack. These streaks are caused by the bow-shock/wing-shock interaction and formation of the wing-shock. Embedded vorticity was found to be associated with these interactions.

  12. Performance Evaluation of Low/Zero Voltage Ride-Through Operations for Single-Stage Single-Phase Photovoltaic Inverters

    DEFF Research Database (Denmark)

    Zhang, Zhen; Yang, Yongheng; Blaabjerg, Frede

    2017-01-01

    With the fast development of distributed power generations, stability and security have attracted extensive attention in the recent years. As a representative of clean energies, Photovoltaic (PV) systems have been installed extensively worldwide. This drives grid-connected requirements to be cont......With the fast development of distributed power generations, stability and security have attracted extensive attention in the recent years. As a representative of clean energies, Photovoltaic (PV) systems have been installed extensively worldwide. This drives grid-connected requirements......-connected single-stage single-phase PV systems in the case of Low/Zero Voltage Ride-Through (LVRT/ZVRT) operation. A comparative analysis of the two LVRT/ZVRT control methods for PV systems is presented. Simulation results are presented, which verifies that the LVRT/ZVRT methods can help the PV systems...... to temporarily ride-through the grid low-/zero-voltage faults. The power phase-angle control method has a better dynamic response....

  13. Rapid determination of 210Po in water samples

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.; Utsey, Robin C.; McAlister, Daniel R.

    2013-08-02

    A new rapid method for the determination of 210Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that can be used for emergency response or routine water analyses. If a radiological dispersive device (RDD) event or a radiological attack associated with drinking water supplies occurs, there will be an urgent need for rapid analyses of water samples, including drinking water, ground water and other water effluents. Current analytical methods for the assay of 210Po in water samples have typically involved spontaneous auto-deposition of 210Po onto silver or other metal disks followed by counting by alpha spectrometry. The auto-deposition times range from 90 minutes to 24 hours or more, at times with yields that may be less than desirable. If sample interferences are present, decreased yields and degraded alpha spectrums can occur due to unpredictable thickening in the deposited layer. Separation methods have focused on the use of Sr Resin, often in combination with 210Pb analysis. A new rapid method for 210Po in water samples has been developed at the Savannah River National Laboratory (SRNL) that utilizes a rapid calcium phosphate co-precipitation method, separation using DGA Resin (N,N,N,N-tetraoctyldiglycolamide extractant-coated resin, Eichrom Technologies or Triskem-International), followed by rapid microprecipitation of 210Po using bismuth phosphate for counting by alpha spectrometry. This new method can be performed quickly with excellent removal of interferences, high chemical yields and very good alpha peak resolution, eliminating any potential problems with the alpha source preparation for emergency or routine samples. A rapid sequential separation method to separate 210Po and actinide isotopes was also developed. This new approach, rapid separation with DGA Resin plus microprecipitation for alpha source preparation, is a significant advance in

  14. Physicochemical transformation and algal toxicity of engineered nanoparticles in surface water samples

    International Nuclear Information System (INIS)

    Zhang, Luqing; Li, Jingyi; Yang, Kun; Liu, Jingfu; Lin, Daohui

    2016-01-01

    Most studies on the behavior and toxicity of engineered nanoparticles (NPs) have been conducted in artificial water with well-controlled conditions, which are dramatically different from natural waters with complex compositions. To better understand the fate and toxicity of NPs in the natural water environment, physicochemical transformations of four NPs (TiO 2 , ZnO, Ag, and carbon nanotubes (CNTs)) and their toxicities towards a unicellular green alga (Chlorella pyrenoidosa) in four fresh water and one seawater sample were investigated. Results indicated that water chemistry had profound effects on aggregation, dissolution, and algal toxicity of the NPs. The strongest homoaggregation of the NPs was associated with the highest ionic strength, but no obvious correlation was observed between the homoaggregation of NPs and pH or dissolved organic matter content of the water samples. The greatest dissolution of ZnO NPs also occurred in seawater with the highest ionic strength, while the dissolution of Ag NPs varied differently from ZnO NPs. The released Zn 2+ and especially Ag + mainly accounted for the algal toxicity of ZnO and Ag NPs, respectively. The NP-cell heteroagglomeration occurred generally for CNTs and Ag NPs, which contributed to the observed nanotoxicity. However, there was no significant correlation between the observed nanotoxicity and the type of NP or the water chemistry. It was thus concluded that the physicochemical transformations and algal toxicities of NPs in the natural water samples were caused by the combined effects of complex water quality parameters rather than any single influencing factor alone. These results will increase our knowledge on the fate and effects of NPs in the aquatic environment. - Highlights: • Transformation and algal toxicity of four NPs in five surface water samples were studied. • The transformation and toxicity were dependent on the types of NPs and water samples. • No single water parameter alone was

  15. Efficacy of single-stage and two-stage Fowler–Stephens laparoscopic orchidopexy in the treatment of intraabdominal high testis

    Directory of Open Access Journals (Sweden)

    Chang-Yuan Wang

    2017-11-01

    Conclusion: In the case of testis with good collateral circulation, single-stage F-S laparoscopic orchidopexy had the same safety and efficacy as the two-stage F-S procedure. Surgical options should be based on comprehensive consideration of intraoperative testicular location, testicular ischemia test, and collateral circumstances surrounding the testes. Under the appropriate conditions, we propose single-stage F-S laparoscopic orchidopexy be preferred. It may be appropriate to avoid unnecessary application of the two-stage procedure that has a higher cost and causes more pain for patients.

  16. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  17. Evaluation of the Validity of Groundwater Samples Obtained Using the Purge Water Management System at SRS

    International Nuclear Information System (INIS)

    Beardsley, C.C.

    1999-01-01

    As part of the demonstration testing of the Purge Water Management System (PWMS) technology at the Savannah River Site (SRS), four wells were equipped with PWMS units in 1997 and a series of sampling events were conducted at each during 1997-1998. Three of the wells were located in A/M Area while the fourth was located at the Old Radioactive Waste Burial Ground in the General Separations Area.The PWMS is a ''closed-loop'', non-contact, system used to collect and return purge water to the originating aquifer after a sampling event without having significantly altered the water quality. One of the primary concerns as to its applicability at SRS, and elsewhere, is whether the PWMS might resample groundwater that is returned to the aquifer during the previous sampling event. The purpose of the present investigation was to compare groundwater chemical analysis data collected at the four test wells using the PWMS vs. historical data collected using the standard monitoring program methodology to determine if the PWMS provides representative monitoring samples.The analysis of the groundwater chemical concentrations indicates that the PWMS sampling methodology acquired representative groundwater samples at monitoring wells ABP-1A, ABP-4, ARP-3 and BGO-33C. Representative groundwater samples are achieved if the PWMS does not resample groundwater that has been purged and returned during a previous sampling event. Initial screening calculations, conducted prior to the selection of these four wells, indicated that groundwater velocities were high enough under the ambient hydraulic gradients to preclude resampling from occurring at the time intervals that were used at each well. Corroborating evidence included a tracer test that was conducted at BGO-33C, the high degree of similarity between analyte concentrations derived from the PWMS samples and those obtained from historical protocol sampling, as well as the fact that PWMS data extend all previously existing concentration

  18. Ground-Water Issue: Soil sampling and analysis for volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, T.E.; Crockett, A.B.; Siegrist, R.L.; Zarrabi, K.

    1991-02-01

    The Regional Superfund Ground Water Forum is a group of ground-water scientists that represents EPA's Regional Superfund Offices. The forum was organized to exchange up-to-date information related to groundwater remediation at Superfund sites. Sampling of soils for volatile organic compounds (VOCs) is an issue identified by the Ground Water Forum as a concern of Superfund decision makers. Concerns over data quality have raised many questions related to sampling soils for VOCs. This paper was prepared in response to some of these questions and concerns expressed by Remedial Project Managers (RPMs) and On-Scene Coordinators (OSCs). 53 refs., 6 figs., 12 tabs.

  19. Characterization samples of Tigris river water treated with nano colloidal silver (physically, chemically, microbiologically)

    International Nuclear Information System (INIS)

    Dumboos, H. I.; Beden, S. J.; Zouari, K.; Chkir, N.; Ahmed, H. A.

    2012-12-01

    Many researches of using nano silver in purification of drinking water from bacteria and its effect on stan dared properties as drinking water were established. Two stages accomplished in these projects. First stage include preparation of colloidal silver with characterization process and prepare water samples through sedimentation, filtration process, PH and turbidity measure then treated with colloidal silver in volume ratio (0.1-Λ) ml/100ml. The second stage represent select the better results from stage one and take samples to determine the standard characterization values with chemical, physical and microbiological taste. Results will be compared with Iraq standard certification. (Author)

  20. Study of the concentration of 7 Be in samples of rain water

    International Nuclear Information System (INIS)

    Quintero P, E.; Rojas M, V.P.

    2004-01-01

    This work shows the methodology carried out for the determination of 7 Be in samples of rain water and the obtained results of the concentration of having said radionuclide in this sampled matrix during the last five years in the Nuclear Center of Mexico. (Author)

  1. HYDROLYSIS OF MTBE IN GROUND WATER SAMPLES PRESERVED WITIH HYDROCHLORIC ACID

    Science.gov (United States)

    Conventional sampling and analytical protocols have poor sensitivity for fuel oxygenates that are alcohols, such as TBA. Because alcohols tend to stay with the water samples, they are not efficiently transferred to the gas chromatograph for separation and analysis. A common tec...

  2. Use of passive sampling devices for monitoring and compliance checking of POP concentrations in water

    NARCIS (Netherlands)

    Lohmann, R.; Booij, K.; Smedes, F.; Vrana, B.

    2012-01-01

    The state of the art of passive water sampling of (nonpolar) organic contaminants is presented. Its suitability for regulatory monitoring is discussed, with an emphasis on the information yielded by passive sampling devices (PSDs), their relevance and associated uncertainties. Almost all persistent

  3. DETERMINATION OF ORGANOCHLORINE PESTICIDES IN DRINKING WATERS SAMPLED FROM CLUJ AND HUNEDOARA COUNTIES

    Directory of Open Access Journals (Sweden)

    MARIA-ELISABETA LOVÁSZ

    2011-03-01

    Full Text Available Determination of organochlorine pesticides in drinking waterssampled from Cluj and Hunedoara counties. Pesticides are found scattered indifferent environmental factors (water, air, soil wherefrom they are drawn off byvegetal and animal organisms. Water pollution by pesticides results from the plantprotection products industry and also from massive application of these resourcesin agriculture and other branches of economy. Pesticides can reach surface wateralong with dripping waters and by infiltration may reach the groundwater layers,organochlorine pesticides are most often found in the water sources (dieldrin,endrin, DDT, aldrin, lindane, heptachlor, etc. due to their increased persistence inthe external environment. This study followed up the determination oforganochlorine pesticides in 14 drinking water samples collected from the outputof water treatment plants in Cluj and Hunedoara counties that process surfacewater and deep-water sources. For identification of organochlorine pesticides, thegas chromatographic method after liquid-liquid extraction was used, by a gascromatograph Shimadzu GC 2010 with detector ECD (Electron CaptureDetection. There were not detected higher values than the method detection limit(0.01 μg/l in the drinking water samples collected and analyzed for both totalorganochlorine pesticides and components, which were well below the maximumconcentration admitted by Law 452/2002 regarding drinking water quality. Resultsare correlated with the sanitary protection areas for water sources and with the useof agricultural lands in the area. The solution to reduce risk of pesticides use isecological agriculture , which gains increasingly more ground in Romania too.

  4. [Detecting Thallium in Water Samples using Dispersive Liquid Phase Microextraction-Graphite Furnace Atomic Absorption Spectroscopy].

    Science.gov (United States)

    Zhu, Jing; Li, Yan; Zheng, Bo; Tang, Wei; Chen, Xiao; Zou, Xiao-li

    2015-11-01

    To develope a method of solvent demulsification dispersive liquid phase microextraction (SD-DLPME) based on ion association reaction coupled with graphite furnace atomic absorption spectroscopy (GFAAS) for detecting thallium in water samples. Methods Thallium ion in water samples was oxidized to Tl(III) with bromine water, which reacted with Cl- to form TlCl4-. The ionic associated compound with trioctylamine was obtained and extracted. DLPME was completed with ethanol as dispersive solvent. The separation of aqueous and organic phase was achieved by injecting into demulsification solvent without centrifugation. The extractant was collected and injected into GFAAS for analysis. With palladium colloid as matrix modifier, a two step drying and ashing temperature programming process was applied for high precision and sensitivity. The linear range was 0.05-2.0 microg/L, with a detection limit of 0.011 microg/L. The relative standard derivation (RSD) for detecting Tl in spiked water sample was 9.9%. The spiked recoveries of water samples ranged from 94.0% to 103.0%. The method is simple, sensitive and suitable for batch analysis of Tl in water samples.

  5. Set Up of an Automatic Water Quality Sampling System in Irrigation Agriculture

    Directory of Open Access Journals (Sweden)

    Emanuel Heinz

    2013-12-01

    Full Text Available We have developed a high-resolution automatic sampling system for continuous in situ measurements of stable water isotopic composition and nitrogen solutes along with hydrological information. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS for stable water isotope analysis (δ2H and δ18O, a reagentless hyperspectral UV photometer (ProPS for monitoring nitrate content and various water level sensors for hydrometric information. The automatic sampling system consists of different sampling stations equipped with pumps, a switch cabinet for valve and pump control and a computer operating the system. The complete system is operated via internet-based control software, allowing supervision from nearly anywhere. The system is currently set up at the International Rice Research Institute (Los Baños, The Philippines in a diversified rice growing system to continuously monitor water and nutrient fluxes. Here we present the system’s technical set-up and provide initial proof-of-concept with results for the isotopic composition of different water sources and nitrate values from the 2012 dry season.

  6. Effects of sterilization treatments on the analysis of TOC in water samples.

    Science.gov (United States)

    Shi, Yiming; Xu, Lingfeng; Gong, Dongqin; Lu, Jun

    2010-01-01

    Decomposition experiments conducted with and without microbial processes are commonly used to study the effects of environmental microorganisms on the degradation of organic pollutants. However, the effects of biological pretreatment (sterilization) on organic matter often have a negative impact on such experiments. Based on the principle of water total organic carbon (TOC) analysis, the effects of physical sterilization treatments on determination of TOC and other water quality parameters were investigated. The results revealed that two conventional physical sterilization treatments, autoclaving and 60Co gamma-radiation sterilization, led to the direct decomposition of some organic pollutants, resulting in remarkable errors in the analysis of TOC in water samples. Furthermore, the extent of the errors varied with the intensity and the duration of sterilization treatments. Accordingly, a novel sterilization method for water samples, 0.45 microm micro-filtration coupled with ultraviolet radiation (MCUR), was developed in the present study. The results indicated that the MCUR method was capable of exerting a high bactericidal effect on the water sample while significantly decreasing the negative impact on the analysis of TOC and other water quality parameters. Before and after sterilization treatments, the relative errors of TOC determination could be controlled to lower than 3% for water samples with different categories and concentrations of organic pollutants by using MCUR.

  7. Set up of an automatic water quality sampling system in irrigation agriculture.

    Science.gov (United States)

    Heinz, Emanuel; Kraft, Philipp; Buchen, Caroline; Frede, Hans-Georg; Aquino, Eugenio; Breuer, Lutz

    2013-12-23

    We have developed a high-resolution automatic sampling system for continuous in situ measurements of stable water isotopic composition and nitrogen solutes along with hydrological information. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water) in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS) for stable water isotope analysis (δ2H and δ18O), a reagentless hyperspectral UV photometer (ProPS) for monitoring nitrate content and various water level sensors for hydrometric information. The automatic sampling system consists of different sampling stations equipped with pumps, a switch cabinet for valve and pump control and a computer operating the system. The complete system is operated via internet-based control software, allowing supervision from nearly anywhere. The system is currently set up at the International Rice Research Institute (Los Baños, The Philippines) in a diversified rice growing system to continuously monitor water and nutrient fluxes. Here we present the system's technical set-up and provide initial proof-of-concept with results for the isotopic composition of different water sources and nitrate values from the 2012 dry season.

  8. Determination of total alpha index in samples of see water by coprecipitation method

    International Nuclear Information System (INIS)

    Suarez-Navarro, J.A.; Pujol, L.; Pozuelo, M.; Pablo, A. de

    1998-01-01

    An environmental radiological monitoring network in the Spanish sea waters was set up by CEDEX in 1993. Water radioactivity is determined quarterly in eleven sampling points along the Spanish coast. The gross alpha activity is one of the parameters to be determined. The usual method for monitoring the gross alpha activity includes sample evaporation to dryness on a disk and counting using ZnS(Ag) scintillation detector. Nevertheless, the gross alpha activity determination in saline waters, such as sea waters, is troublesome, because mass attenuation is high and a very small of water is needed (0.2 ml). The coprecipitation method allows to analyze 500 ml water samples, so the detection limit is reduced and sensitivity is improved. In this work, the coprecipitation method was used to determine the gross alpha activity in the radiological network of the Spanish coast sea waters during 1996 and 1997. Gross alpha activity was very homogenous. It averaged 0.0844±0.0086 Bq.1''1 and ranged from 0.062 to 0.102 Bq.1''1. In collaboration with CIEMAT a set of samples was analyzed, they averaged 0.0689±0.0074 Bq.1''1 and ranged from 0.056 to 0.082 Bq.1''1. (Author) 5 refs

  9. Analysis of bromate in drinking water using liquid chromatography-tandem mass spectrometry without sample pretreatment.

    Science.gov (United States)

    Kosaka, Koji; Asami, Mari; Takei, Kanako; Akiba, Michihiro

    2011-01-01

    An analytical method for determining bromate in drinking water was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The (18)O-enriched bromate was used as an internal standard. The limit of quantification (LOQ) of bromate was 0.2 µg/L. The peak of bromate was separated from those of coexisting ions (i.e., chloride, nitrate and sulfate). The relative and absolute recoveries of bromate in two drinking water samples and in a synthesized ion solution (100 mg/L chloride, 10 mg N/L nitrate, and 100 mg/L sulfate) were 99-105 and 94-105%, respectively. Bromate concentrations in 11 drinking water samples determined by LC-MS/MS were water without sample pretreatment.

  10. Determination of trace water in gas samples by an improved Karl Fischer coulometer.

    Science.gov (United States)

    Dong, Huiru; Bi, Pengyu; Cao, Jianping; Zhao, Shouyong

    2005-04-01

    The determination of trace water in gas samples, such as isobutene, chloromethane (polymeric staple gases) and SF6 by a conventional Karl Fischer coulometer is very difficult, because of the adsorption of trace water on the surface of sample pipe, the gasification of the liquefied samples, and the migration of moisture into the measuring cell from the surroundings. To solve these problems, we improved a device for coulometric determination of water by Karl Fischer method. The improved coulometer was used to determine the trace water in isobutene, chloromethane and SF6; RSD was less than 5%, and recoveries ranged from 94.1 to 109.1%, which is adequate for the analysis of industry.

  11. May 2013 Groundwater and Surface Water Sampling at the Rio Blanco, Colorado, Site (Data Validation Package)

    Energy Technology Data Exchange (ETDEWEB)

    Hutton, Rick [S.M. Stoller Corporation, Broomfield, CO (United States)

    2013-10-01

    Annual sampling was conducted at the Rio Blanco, Colorado, site for the Long-Term Hydrologic Monitoring Program May 14-16, 2013, to monitor groundwater and surface water for potential radionuclide contamination. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for the U.S. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). A duplicate sample was collected from location CER #1 Black Sulphur. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and for tritium using the conventional and enrichment methods.

  12. Identification of Phyllosilicates in Mudstone Samples Using Water Releases Detected by the Sample Analysis at Mars (SAM) Instrument in Gale Crater, Mars

    Science.gov (United States)

    Hogancamp, J. V. (Clark); Ming, D. W.; McAdam, A. C.; Archer, P. D.; Morris, R. V.; Bristow, T. F.; Rampe, E. B.; Mahaffy, P. R.; Gellert, R.

    2017-01-01

    The Sample Analysis at Mars (SAM) instrument on board the Curiosity Rover has detected high temperature water releases from mud-stones in the areas of Yellowknife Bay, Pahrump Hills, Naukluft Plateau, and Murray Buttes in Gale crater. Dehydroxylation of phyllosilicates may have caused the high temperature water releases observed in these samples. Because each type of phyllosilicate undergoes dehydroxylation at distinct temperatures, these water releases can be used to help constrain the type of phyllosilicate present in each sample.

  13. Measurement of the tritium concentration in the fractionated distillate from environmental water samples

    International Nuclear Information System (INIS)

    Atkinson, Robert; Eddy, Teresa; Kuhne, Wendy; Jannik, Tim; Brandl, Alexander

    2014-01-01

    Standard procedures for the measurement of tritium in water samples often require distillation of an appropriate sample aliquot. This distillation process may result in a fractionation of tritiated water and regular light water due to the vapor pressure isotope effect, introducing either a bias or an additional contribution to the total tritium measurement uncertainty. The current study investigates the relative change in vapor pressure isotope effect in the course of the distillation process, distinguishing it from and extending previously published measurements. The separation factor as a quantitative measure of the vapor pressure isotope effect is found to assume values of 1.04 ± 0.036, 1.05 ± 0.026, and 1.07 ± 0.038, depending on the vigor of the boiling process during distillation of the sample. A lower heat setting in the experimental setup, and therefore a less vigorous boiling process, results in a larger value for the separation factor. For a tritium measurement in water samples where the first 5 mL are discarded, the tritium concentration could be underestimated by 4–7%. - Highlights: • Tritium measurements in environmental water samples. • Distilled samples. • Vapor pressure isotope effect. • Depending on boiling mode. • Potential underestimate of tritium activity concentration of 4–7%

  14. Research on How to Remove Efficiently the Condensate Water of Sampling System

    International Nuclear Information System (INIS)

    Cho, SungHwan; Kim, MinSoo; Choi, HoYoung; In, WonHo

    2015-01-01

    Corrosion was caused in the measurement chamber inside the O 2 and H 2 analyzer, and thus measuring the concentration of O 2 and H 2 was not possible. It was confirmed that the cause of the occurrence of condensate water is due to the temperature difference caused during the process of the internal gas of the disposal and degasifier tank being brought into the analyzer. Thus, a heating system was installed inside and outside of the sampling panel for gas to remove generated condensate water in the analyzer and pipe. For the case where condensate water is not removed by the heating system, drain port is also installed in the sampling panel for gas to collect the condensate water of the sampling system. It was verified that there is a great volume of condensate water existing in the pipe line during the purging process after installing manufactured goods. The condensate water was fully removed by the installed heating cable and drain port. The heating cable was operated constantly at a temperature of 80 to 90 .deg. C, which allows the precise measurement of gas concentration and longer maintenance duration by blocking of the condensate water before being produced. To install instruments for measuring the gas, such as an O 2 and H 2 analyzer etc., consideration regarding whether there condensate water is present due to the temperature difference between the measuring system and analyzer is required

  15. Research on How to Remove Efficiently the Condensate Water of Sampling System

    Energy Technology Data Exchange (ETDEWEB)

    Cho, SungHwan; Kim, MinSoo; Choi, HoYoung; In, WonHo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Corrosion was caused in the measurement chamber inside the O{sub 2} and H{sub 2} analyzer, and thus measuring the concentration of O{sub 2} and H{sub 2} was not possible. It was confirmed that the cause of the occurrence of condensate water is due to the temperature difference caused during the process of the internal gas of the disposal and degasifier tank being brought into the analyzer. Thus, a heating system was installed inside and outside of the sampling panel for gas to remove generated condensate water in the analyzer and pipe. For the case where condensate water is not removed by the heating system, drain port is also installed in the sampling panel for gas to collect the condensate water of the sampling system. It was verified that there is a great volume of condensate water existing in the pipe line during the purging process after installing manufactured goods. The condensate water was fully removed by the installed heating cable and drain port. The heating cable was operated constantly at a temperature of 80 to 90 .deg. C, which allows the precise measurement of gas concentration and longer maintenance duration by blocking of the condensate water before being produced. To install instruments for measuring the gas, such as an O{sub 2} and H{sub 2} analyzer etc., consideration regarding whether there condensate water is present due to the temperature difference between the measuring system and analyzer is required.

  16. Concentration of polycyclic aromatic hydrocarbons in water samples from different stages of treatment

    Directory of Open Access Journals (Sweden)

    Pogorzelec Marta

    2017-01-01

    Full Text Available The aim of this study was to analyze the presence and concentration of selected polycyclic aromatic hydrocarbons in water samples from different stages of treatment and to verify the usefulness of semipermeable membrane devices for analysis of drinking water. For this purpose, study was conducted for a period of 5 months. Semipermeable membrane devices were deployed in a surface water treatment plant located in Lower Silesia (Poland. To determine the effect of water treatment on concentration of PAHs, three sampling places were chosen: raw water input, stream of water just before disinfection and treated water output. After each month of sampling SPMDs were changed for fresh ones and prepared for further analysis. Concentrations of fifteen polycyclic aromatic hydrocarbons were determined by high performance liquid chromatography (HPLC. Presented study indicates that the use of semipermeable membrane devices can be an effective tool for the analysis of aquatic environment, including monitoring of drinking water, where organic micropollutants are present at very low concentrations.

  17. Presence of Cryptosporidium spp. and Giardia duodenalis in Drinking Water Samples in the North of Portugal

    Science.gov (United States)

    Moreira, Maria João; Soares, Sónia; de Lurdes Delgado, Maria; Figueiredo, João; Silva, Elisabete; Castro, António; Cosa, José Manuel Correida Da

    2010-01-01

    Cryptosporidium and Giardia are 2 protozoan parasites responsible for waterborne diseases outbreaks worldwide. In order to assess the prevalence of these protozoans in drinking water samples in the northern part of Portugal and the risk of human infection, we have established a long term program aiming at pinpointing the sources of surface water, drinking water, and environmental contamination, working with the water-supply industry. Total 43 sources of drinking water samples were selected, and a total of 167 samples were analyzed using the Method 1623. Sensitivity assays regarding the genetic characterization by PCR and sequencing of the genes, 18S SSU rRNA, for Cryptosporidium spp. and β,-giardin for G. duodenalis were set in the laboratory. According to the defined criteria, molecular analysis was performed over 4 samples. Environmental stages of the protozoa were detected in 25.7% (43 out of 167) of the water samples, 8.4% (14 out of 167) with cysts of Giardia, 10.2% (17 out of 167) with oocysts of Cryptosporidium and 7.2% (12 out of 167) for both species. The mean concentrations were 0.1-12.7 oocysts of Cryptosporidium spp. per 10 L and 0.1-108.3 cysts of Giardia duodenalis per 10 L. Our results suggest that the efficiency in drinking water plants must be ameliorated in their efficiency in reducing the levels of contamination. We suggest the implementation of systematic monitoring programs for both protozoa. To authors' knowledge, this is the first report evaluating the concentration of environmental stages of Cryptosporidium and Giardia in drinking water samples in the northern part of Portugal. PMID:20333284

  18. Presence of Cryptosporidium spp. and Giardia duodenalis in drinking water samples in the north of Portugal.

    Science.gov (United States)

    Almeida, André; Moreira, Maria João; Soares, Sónia; Delgado, Maria de Lurdes; Figueiredo, João; Silva, Elisabete; Castro, António; Cosa, José Manuel Correida Da

    2010-03-01

    Cryptosporidium and Giardia are 2 protozoan parasites responsible for waterborne diseases outbreaks worldwide. In order to assess the prevalence of these protozoans in drinking water samples in the northern part of Portugal and the risk of human infection, we have established a long term program aiming at pinpointing the sources of surface water, drinking water, and environmental contamination, working with the water-supply industry. Total 43 sources of drinking water samples were selected, and a total of 167 samples were analyzed using the Method 1623. Sensitivity assays regarding the genetic characterization by PCR and sequencing of the genes, 18S SSU rRNA, for Cryptosporidium spp. and beta,-giardin for G. duodenalis were set in the laboratory. According to the defined criteria, molecular analysis was performed over 4 samples. Environmental stages of the protozoa were detected in 25.7% (43 out of 167) of the water samples, 8.4% (14 out of 167) with cysts of Giardia, 10.2% (17 out of 167) with oocysts of Cryptosporidium and 7.2% (12 out of 167) for both species. The mean concentrations were 0.1-12.7 oocysts of Cryptosporidium spp. per 10 L and 0.1-108.3 cysts of Giardia duodenalis per 10 L. Our results suggest that the efficiency in drinking water plants must be ameliorated in their efficiency in reducing the levels of contamination. We suggest the implementation of systematic monitoring programs for both protozoa. To authors' knowledge, this is the first report evaluating the concentration of environmental stages of Cryptosporidium and Giardia in drinking water samples in the northern part of Portugal.

  19. Detection of protozoa in water samples by formalin/ether concentration method.

    Science.gov (United States)

    Lora-Suarez, Fabiana; Rivera, Raul; Triviño-Valencia, Jessica; Gomez-Marin, Jorge E

    2016-09-01

    Methods to detect protozoa in water samples are expensive and laborious. We evaluated the formalin/ether concentration method to detect Giardia sp., Cryptosporidium sp. and Toxoplasma in water. In order to test the properties of the method, we spiked water samples with different amounts of each protozoa (0, 10 and 50 cysts or oocysts) in a volume of 10 L of water. Immunofluorescence assay was used for detection of Giardia and Cryptosporidium. Toxoplasma oocysts were identified by morphology. The mean percent of recovery in 10 repetitions of the entire method, in 10 samples spiked with ten parasites and read by three different observers, were for Cryptosporidium 71.3 ± 12, for Giardia 63 ± 10 and for Toxoplasma 91.6 ± 9 and the relative standard deviation of the method was of 17.5, 17.2 and 9.8, respectively. Intraobserver variation as measured by intraclass correlation coefficient, was fair for Toxoplasma, moderate for Cryptosporidium and almost perfect for Giardia. The method was then applied in 77 samples of raw and drinkable water in three different plant of water treatment. Cryptosporidium was found in 28 of 77 samples (36%) and Giardia in 31 of 77 samples (40%). Theses results identified significant differences in treatment process to reduce the presence of Giardia and Cryptosporidium. In conclusion, the formalin ether method to concentrate protozoa in water is a new alternative for low resources countries, where is urgently need to monitor and follow the presence of theses protozoa in drinkable water. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Effects of soil water saturation on sampling equilibrium and kinetics of selected polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Kim, Pil-Gon; Roh, Ji-Yeon; Hong, Yongseok; Kwon, Jung-Hwan

    2017-10-01

    Passive sampling can be applied for measuring the freely dissolved concentration of hydrophobic organic chemicals (HOCs) in soil pore water. When using passive samplers under field conditions, however, there are factors that might affect passive sampling equilibrium and kinetics, such as soil water saturation. To determine the effects of soil water saturation on passive sampling, the equilibrium and kinetics of passive sampling were evaluated by observing changes in the distribution coefficient between sampler and soil (K sampler/soil ) and the uptake rate constant (k u ) at various soil water saturations. Polydimethylsiloxane (PDMS) passive samplers were deployed into artificial soils spiked with seven selected polycyclic aromatic hydrocarbons (PAHs). In dry soil (0% water saturation), both K sampler/soil and k u values were much lower than those in wet soils likely due to the contribution of adsorption of PAHs onto soil mineral surfaces and the conformational changes in soil organic matter. For high molecular weight PAHs (chrysene, benzo[a]pyrene, and dibenzo[a,h]anthracene), both K sampler/soil and k u values increased with increasing soil water saturation, whereas they decreased with increasing soil water saturation for low molecular weight PAHs (phenanthrene, anthracene, fluoranthene, and pyrene). Changes in the sorption capacity of soil organic matter with soil water content would be the main cause of the changes in passive sampling equilibrium. Henry's law constant could explain the different behaviors in uptake kinetics of the selected PAHs. The results of this study would be helpful when passive samplers are deployed under various soil water saturations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Effects of physical and chemical heterogeneity on water-quality samples obtained from wells

    Science.gov (United States)

    Reilly, Thomas E.; Gibs, Jacob

    1993-01-01

    Factors that affect the mass of chemical constituents entering a well include the distributions of flow rate and chemical concentrations along and near the screened or open section of the well. Assuming a layered porous medium (with each layer being characterized by a uniform hydraulic conductivity and chemical concentration), a knowledge of the flow from each layer along the screened zone and of the chemical concentrations in each layer enables the total mass entering the well to be determined. Analyses of hypothetical systems and a site at Galloway, NJ, provide insight into the temporal variation of water-quality data observed when withdrawing water from screened wells in heterogeneous ground-water systems.The analyses of hypothetical systems quantitatively indicate the cause-and-effect relations that cause temporal variability in water samples obtained from wells. Chemical constituents that have relatively uniform concentrations with depth may not show variations in concentrations in the water discharged from a well after the well is purged (evacuation of standing water in the well casing). However, chemical constituents that do not have uniform concentrations near the screened interval of the well may show variations in concentrations in the well discharge water after purging because of the physics of ground-water flow in the vicinity of the screen.Water-quality samples were obtained through time over a 30 minute period from a site at Galloway, NJ. The water samples were analyzed for aromatic hydrocarbons, and the data for benzene, toluene, and meta+para xylene were evaluated for temporal variations. Samples were taken from seven discrete zones, and the flow-weighted concentrations of benzene, toluene, and meta+para xylene all indicate an increase in concentration over time during pumping. These observed trends in time were reproduced numerically based on the estimated concentration distribution in the aquifer and the flow rates from each zone.The results of

  2. Trace element analysis of mineral water samples by PIXE and ICP-MS

    International Nuclear Information System (INIS)

    Kennedy, V.John; Augusthy, A.; Varier, K. M.; Magudapathy, P.; Panchapakesan, S.; Nair, K.G.M.

    1998-01-01

    Trace elements present in bottled mineral water have been studied by PIXE and ICP-MS. Samples from ten different brands of brands of bottled mineral water were prepared by preconcentration techniques. Measurements were carried out using the 2 MeV proton beam obtained from 3 MV Tandem pelletron accelerator at the Institute of Physics, Bhubaneswar. Our results are compared with Indian standard packaged natural mineral water specifications, World Health Organisation (WHO) and European guidelines for drinking water standards. Concentration of aluminum was found to be more in one of the brands. In general, our results are comparable to the above standards. (author)

  3. The natural and artificial radionuclides in drinking water samples and consequent population doses

    Directory of Open Access Journals (Sweden)

    Aydan Altıkulaç

    2015-10-01

    Full Text Available Concentration levels of 226Ra, 228Ra, 40K and 137Cs were determined in 52 drinking water samples collected from the different supplies in Samsun province to evaluate annual effective dose due to the ingestion of the drinking water samples. The activity concentrations of 226Ra, 228Ra and 40K natural radionuclides in the drinking water samples varied from <27 to 2431 mBq L−1, <36 to 270 mBq L−1 and <47 to 2880 mBq L−1 respectively. The activity concentrations of the artificial radionuclide 137Cs in the drinking water samples were lower than minimum detectable activity except in one drinking water sample (DW14 with an associated activity concentration of 2576 mBq L−1. Contributions of the consumed water samples to annual effective dose from 226Ra, 228Ra and 40K varied from 1.6 to 33.4 μSv y−1 with a mean of 6.1 μSv y−1, 2.2 to 46.8 μSv y−1 with a mean of 8.6 μSv y−1, 4.7 to 97.5 μSv y−1 with a mean of 17.9 μSv y−1 for infants, children and adults, respectively. The results showed that all values of the annual effective dose of ingestion of these water samples were below the individual dose criterion of 100 μSv y−1 reported by World Health Organization (WHO.

  4. Evaluation of a single-stage consumable-free modulator for comprehensive two-dimensional gas chromatography: analysis of polychlorinated biphenyls, organochlorine pesticides and chlorobenzenes.

    Science.gov (United States)

    Muscalu, Alina M; Edwards, Matthew; Górecki, Tadeusz; Reiner, Eric J

    2015-04-24

    Comprehensive two-dimensional gas chromatography (GC×GC) has been rapidly growing in popularity. The GC×GC separation is performed by interfacing a modulator between two columns of different selectivities. The modulator periodically traps and then re-injects the analytes eluting from the first column into the second column. The most popular GC×GC systems require consumables such as liquid N2 for the trapping function of the modulator. Although these systems are very effective, their costs are a hindrance to more widespread use. A new, single-stage thermal modulator for GC×GC that requires no consumables has been developed and tested. The device traps analytes using a proprietary stainless steel capillary trap compressed between two ceramic cooling pads. Analytes are thermally desorbed from the trap into the second column via resistive heating. To evaluate this system, a routine accredited method for the analysis of polychlorinated biphenyls, organochlorine pesticides and chlorobenzenes was run using the new modulator and its performance was compared to that of an industry standard modulation system. Within-day repeatability (% RSD ranging from 2% to 13%), between-day reproducibility (% RSD from 3% to 15%), as well as between-trap reproducibility were assessed. The results are very encouraging as negligible shifts in retention times (% RSD from 0.3% to 0.6% in the 1st dimension and 0.8% to 2% in the 2nd dimension) were observed for both within-day and day-to-day comparisons of the studied samples (ANOVA, p=0.9893 for the sediment reference material compared), and the quantitative results were comparable. Routine analysis and quality control applications will benefit from the improved reproducibility as the variances in cold/hot jet flows and temperatures are eliminated. An overview of the device operation and the results from this study are summarized. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Effects of a saturated layer and recirculation on nitrogen treatment performances of a single stage Vertical Flow Constructed Wetland (VFCW).

    Science.gov (United States)

    Prigent, S; Paing, J; Andres, Y; Chazarenc, F

    2013-01-01

    Upgrades to enhance nitrogen removal were tested in a 2 year old pilot vertical flow constructed wetland in spring and summer periods. The effects of a saturated layer and of recirculation were tested in particular. Two pilots (L = 2 m, W = 1.25 m, H = 1.2 m), filled with expanded schist (Mayennite(®)), were designed with hydraulic saturated layers of 20 and 40 cm at the bottom. Each pilot was fed with raw domestic wastewater under field conditions according to a hydraulic load of 15-38 cm d(-1) (i.e. 158-401 g COD (chemical oxygen demand) m(-2) d(-1)) and to recirculation rates ranging from 0% up to 150%. The initial load during the first 2 years of operation resulted in an incomplete mineralized accumulated sludge leading to total suspended solids (TSS), COD and biochemical oxygen demand (BOD5) release. A 40 cm hydraulic saturated layer enabled an increase of 5-10% total nitrogen (TN) removal compared to a 20 cm saturated layer. Recirculation allowed the dilution of raw wastewater and enhanced nitrification in a single stage. A design of 1.8 m² pe(-1) (48 cm d(-1), 191 g COD m(-2) d(-1)) with a 40 cm saturated layer and 100% recirculation enabled the French standard D4 (35 mg TSS L(-1), 125 mg COD L(-1), 25 mg BOD5 L(-1)), nitrogen concentrations below 20 mg TKN (total Kjeldahl nitrogen) L(-1) and 50 mg TN L(-1), to be met.

  6. Influence of the effectiveness of raw materials on the reliability of thermoelectric cooling devices. Part I: single-stage TEDs

    Directory of Open Access Journals (Sweden)

    Zaikov V. P.

    2015-02-01

    Full Text Available Increase of the reliability of information systems depends on the reliability improvement of their component elements, including cooling devices, providing efficiency of thermally loaded components. Thermoelectric devices based on the Peltier effect have significant advantages compared with air and liquid systems for thermal modes of the radio-electronic equipment. This happens due to the absence of moving parts, which account for the failure rate. The article presents research results on how thermoelectric efficiency modules affect the failure rate and the probability of non-failure operation in the range of working temperature of thermoelectric coolers. The authors investigate a model of relative failure rate and the probability of failure-free operation single-stage thermoelectric devices depending on the main relevant parameters: the operating current flowing through the thermocouple and resistance, temperature changes, the magnitude of the heat load and the number of elements in the module. It is shown that the increase in the thermoelectric efficiency of the primary material for a variety of thermocouple temperature changes causes the following: maximum temperature difference increases by 18%; the number of elements in the module decreases; cooling coefficient increases; failure rate reduces and the probability of non-failure operation of thermoelectric cooling device increases. Material efficiency increase by 1% allows reducing failure rate by 2,6—4,3% in maximum refrigeration capacity mode and by 4,2—5,0% in minimal failure rate mode when temperature difference changes in the range of 40—60 K. Thus, the increase in the thermoelectric efficiency of initial materials of thermocouples can significantly reduce the failure rate and increase the probability of failure of thermoelectric coolers depending on the temperature difference and the current operating mode.

  7. Prospective study of single-stage repair of contaminated hernias using a biologic porcine tissue matrix: the RICH Study.

    Science.gov (United States)

    Itani, Kamal M F; Rosen, Michael; Vargo, Daniel; Awad, Samir S; Denoto, George; Butler, Charles E

    2012-09-01

    In the presence of contamination, the repair of a ventral incisional hernia (VIH) is challenging. The presence of comorbidities poses an additional risk for postoperative wound events and hernia recurrence. To date, very few studies describe the outcomes of VIH repair in this high-risk population. A prospective, multicenter, single-arm, the Repair of Infected or Contaminated Hernias study was performed to study the clinical outcomes of open VIH repair of contaminated abdominal defects with a non-cross-linked, porcine, acellular dermal matrix, Strattice. Of 85 patients who consented to participate, 80 underwent open VIH repair with Strattice. Hernia defects were 'clean-contaminated' (n = 39), 'contaminated' (n = 39), or 'dirty' (n = 2), and the defects were classified as grade 3 (n = 60) or grade 4 (n = 20). The midline was restored, and primary closure was achieved in 64 patients; the defect was bridged in 16 patients. At 24 months, 53 patients (66%) experienced 95 wound events. There were 28 unique, infection-related events in 24 patients. Twenty-two patients experienced seromas, all but 5 of which were transient and required no intervention. No unanticipated adverse events occurred, and no tissue matrix required complete excision. There were 22 hernia (28%) recurrences by month 24. There was no correlation between infection-related events and hernia recurrence. The use of the intact, non-cross-linked, porcine, acellular dermal matrix, Strattice, in the repair of contaminated VIH in high-risk patients allowed for successful, single-stage reconstruction in >70% of patients followed for 24 months after repair. Published by Mosby, Inc.

  8. Monitoring water quality in Toronto's urban stormwater ponds: Assessing participation rates and data quality of water sampling by citizen scientists in the FreshWater Watch.

    Science.gov (United States)

    Scott, Andrew B; Frost, Paul C

    2017-08-15

    From 2013 to 2015, citizen scientist volunteers in Toronto, Canada were trained to collect and analyze water quality in urban stormwater ponds. This volunteer sampling was part of the research program, FreshWater Watch (FWW), which aimed to standardize urban water sampling efforts from around the globe. We held training sessions for new volunteers twice yearly and trained a total of 111 volunteers. Over the course of project, ~30% of volunteers participated by collecting water quality data after the training session with 124 individual sampling events at 29 unique locations in Toronto, Canada. A few highly engaged volunteers were most active, with 50% of the samples collected by 5% of trainees. Stormwater ponds generally have poor water quality demonstrated by elevated phosphate concentrations (~30μg/L), nitrate (~427μg/L), and turbidity relative to Canadian water quality standards. Compared to other urban waterbodies in the global program, nutrient concentrations in Toronto's urban stormwater ponds were lower, while turbidity was not markedly different. Toronto FWW (FWW-TO) data was comparable to that measured by standard lab analyses and matched results from previous studies of stormwater ponds in Toronto. Combining observational and chemical data acquired by citizen scientists, macrophyte dominated ponds had lower phosphate concentrations while phytoplankton dominated ponds had lower nitrate concentrations, which indicates a potentially important and unstudied role of internal biogeochemical processes on pond nutrient dynamics. This experience in the FWW demonstrates the capabilities and constraints of citizen science when applied to water quality sampling. While analytical limits on in-field analyses produce higher uncertainty in water quality measurements of individual sites, rapid data collection is possible but depends on the motivation and engagement of the group of volunteers. Ongoing efforts in citizen science will thus need to address sampling effort

  9. Ground-water sampling of the NNWSI (Nevada Nuclear Waste Storage Investigation) water table test wells surrounding Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Matuska, N.A.

    1988-12-01

    The US Geological Survey (USGS), as part of the Nevada Nuclear Waste Storage Investigation (NNWSI) study of the water table in the vicinity of Yucca Mountain, completed 16 test holes on the Nevada Test Site and Bureau of Land Management-administered lands surrounding Yucca Mountain. These 16 wells are monitored by the USGS for water-level data; however, they had not been sampled for ground-water chemistry or isotropic composition. As part of the review of the proposed Yucca Mountain high-level nuclear waste repository, the Desert Research Institute (DRI) sampled six of these wells. The goal of this sampling program was to measure field-dependent parameters of the water such as electrical conductivity, pH, temperature and dissolved oxygen, and to collect samples for major and minor element chemistry and isotopic analysis. This information will be used as part of a program to geochemically model the flow direction between the volcanic tuff aquifers and the underlying regional carbonate aquifer

  10. Characterization of Listeria monocytogenes isolated from Ganges water, human clinical and milk samples at Varanasi, India.

    Science.gov (United States)

    Soni, Dharmendra K; Singh, Rakesh K; Singh, Durg V; Dubey, Suresh K

    2013-03-01

    Listeria monocytogenes isolated from Ganges water, human clinical and milk samples were characterized by antibiotic susceptibility, serotype identification, detection of virulence genes and ERIC- and REP-PCR fingerprint analyses. All isolates were uniformly resistant to ampicillin, except two isolates, and showed variable resistance to gentamicin, cotrimoxazole, ofloxacin, rifampicin and tetracycline. Of the 20 isolates found positive for pathogens, seven (four human and three water isolates) belong to serogroups 4b, 4d and 4e; six (one human and five water isolates) belong to serogroups 1/2c and 3c; four milk isolates belong to serogroups 1/2b and 3b; and three milk isolates belong to serogroups 1/2a and 3a. Two water isolates, all human isolates, except one (Pb1) lacking inlJ gene, and three milk isolates possess inlA, inlC, plcA, prfA, actA, hlyA and iap genes. The remaining water and milk isolates showed variable presence of inlJ, plcA, prfA, and iap genes. ERIC- and REP-PCR based analyses collectively indicated that isolates of human clinical samples belong to identical or similar clone and isolates of water and milk samples belong to different clones. Overall study demonstrates the prevalence of pathogenic L. monocytogenes species in the environmental and clinical samples. Most of the isolates were resistant to commonly used antibiotics. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. An Optimized Method for Quantification of Pathogenic Leptospira in Environmental Water Samples.

    Science.gov (United States)

    Riediger, Irina N; Hoffmaster, Alex R; Casanovas-Massana, Arnau; Biondo, Alexander W; Ko, Albert I; Stoddard, Robyn A

    2016-01-01

    Leptospirosis is a zoonotic disease usually acquired by contact with water contaminated with urine of infected animals. However, few molecular methods have been used to monitor or quantify pathogenic Leptospira in environmental water samples. Here we optimized a DNA extraction method for the quantification of leptospires using a previously described Taqman-based qPCR method targeting lipL32, a gene unique to and highly conserved in pathogenic Leptospira. QIAamp DNA mini, MO BIO PowerWater DNA and PowerSoil DNA Isolation kits were evaluated to extract DNA from sewage, pond, river and ultrapure water samples spiked with leptospires. Performance of each kit varied with sample type. Sample processing methods were further evaluated and optimized using the PowerSoil DNA kit due to its performance on turbid water samples and reproducibility. Centrifugation speeds, water volumes and use of Escherichia coli as a carrier were compared to improve DNA recovery. All matrices showed a strong linearity in a range of concentrations from 106 to 10° leptospires/mL and lower limits of detection ranging from Leptospira in environmental waters (river, pond and sewage) which consists of the concentration of 40 mL samples by centrifugation at 15,000×g for 20 minutes at 4°C, followed by DNA extraction with the PowerSoil DNA Isolation kit. Although the method described herein needs to be validated in environmental studies, it potentially provides the opportunity for effective, timely and sensitive assessment of environmental leptospiral burden.

  12. A confirmatory holding time study for purgeable VOCs in water samples

    International Nuclear Information System (INIS)

    West, O.R.; Bayne, C.K.; Siegrist, R.L.; Holden, W.H.; Bottrell, D.W.

    1996-01-01

    Analyte stability during pre-analytical storage is essential to the accurate quantification contaminants in environmental samples. This is particularly true for volatile organic compounds (VOCS) which can easily volatilize and/or degrade during sample storage. Recognizing this, regulatory agencies require water samples be collected in vials without headspace and stored at 4 degrees C, and that analyses be conducted within 14 days, 2048 even if samples are acid-preserved. Since the selection of a 14-day holding time was largely arbitrary, the appropriateness of this requirement must be re-evaluated. The goal of the study described here was to provide regulatory agencies with the necessary data to extend the maximum holding time for properly preserved VOC water samples to 28 days

  13. Preconcentration and determination of heavy metals in water, sediment and biological samples

    Directory of Open Access Journals (Sweden)

    Shirkhanloo Hamid

    2011-01-01

    Full Text Available In this study, a simple, sensitive and accurate column preconcentration method was developed for the determination of Cd, Cu and Pb ions in river water, urine and sediment samples by flame atomic absorption spectrometry. The procedure is based on the retention of the analytes on a mixed cellulose ester membrane (MCEM column from buffered sample solutions and then their elution from the column with nitric acid. Several parameters, such as pH of the sample solution, volume of the sample and eluent and flow rates of the sample were evaluated. The effects of diverse ions on the preconcentration were also investigated. The recoveries were >95 %. The developed method was applied to the determination of trace metal ions in river water, urine and sediment samples, with satisfactory results. The 3δ detection limits for Cu, Pb and Cd were found to be 2, 3 and 0.2 μg dm−3, respectively. The presented procedure was successfully applied for determination of the copper, lead and cadmium contents in real samples, i.e., river water and biological samples.

  14. Cyto- and genotoxic potential of water samples from polluted areas in Kosovo.

    Science.gov (United States)

    Alija, Avdulla J; Bajraktari, Ismet D; Bresgen, Nikolaus; Bojaxhi, Ekramije; Krenn, Margit; Asllani, Fisnik; Eckl, Peter M

    2016-09-01

    Reports on the state of the environment in Kosovo have emphasized that river and ground water quality is affected by pollution from untreated urban water as well as the waste water from the industry. One of the main contributors to this pollution is located in Obiliq (coal power plants). Prishtina-the capital city of Kosovo-is heavily influenced too. Furthermore, the pollutants combined together with those from heavy traffic are dissolved in Prishtina runoff water, which is discharged into the creek entering the river Sitnica together with urban waste water. The available data show the complex pollution with excessive quantities of nitrites, suspended materials, organic compounds, detergents, heavy metals, polychlorinated biphenyls, etc. In this study, the cytotoxic and genotoxic potential of water samples taken at these sites was tested in primary rat hepatocytes. The results obtained indicate that water samples collected in Prishtina and Obiliq had a significant cytotoxic potential in primary rat hepatocyte cultures even when diluted to 1 %. The increased cytotoxicity, however, was not accompanied by an increased genotoxicity as measured by the percentage of micronucleated cells. Further investigations addressing the chemical composition of the samples and the identification of the toxicants responsible for the cytotoxic effects found will be carried out in a next step.

  15. An operational protocol for facilitating start-up of single-stage autotrophic nitrogen-removing reactors based on process stoichiometry

    DEFF Research Database (Denmark)

    Mutlu, Ayten Gizem; Vangsgaard, Anna Katrine; Sin, Gürkan

    2013-01-01

    Start-up and operation of single-stage nitritation–anammox sequencing batch reactors (SBRs) for completely autotrophic nitrogen removal can be challenging and far from trivial. In this study, a step-wise procedure is developed based on stoichiometric analysis of the process performance from...

  16. Clinical and radiologic evaluation of 2-stage IMZ implants placed in a single-stage procedure : 2-year results of a prospective comparative study

    NARCIS (Netherlands)

    Heydenrijk, K; Raghoebar, GM; Meijer, HJA; Stegenga, B

    2003-01-01

    Purpose: The aim of this study was to evaluate the feasibility of using a 2-stage implant system in a single-stage procedure and to study the impact of the microgap between the implant and the abutment. Materials and Methods: Sixty edentulous patients (Cawood class V or VI) participated in this

  17. Temperature-phased anaerobic digestion of food waste: A comparison with single-stage digestions based on performance and energy balance.

    Science.gov (United States)

    Xiao, Benyi; Qin, Yu; Zhang, Wenzhe; Wu, Jing; Qiang, Hong; Liu, Junxin; Li, Yu-You

    2018-02-01

    The temperature-phased anaerobic digestion (TPAD) of food waste was studied for the purpose of comparing with single-stage mesophilic and thermophilic anaerobic digestion. The biogas and methane yields in the TPAD during the steady period were 0.759 ± 0.115 L/g added VS and 0.454 ± 0.201 L/g added VS, which were lower than those in the two single-stage anaerobic digestion. The improper sludge retention time may be the reason for the lower biogas and methane production in TPAD. The removal of volatile solids in the TPAD was 78.55 ± 4.59% and the lowest among the three anaerobic digestion processes. The reaction ratios of the four anaerobic digestion steps in the TPAD were all lower than those in the two single-stage anaerobic digestion. The energy conversion efficiency of the degraded substrate in the TPAD was similar with those in single-stage mesophilic and thermophilic anaerobic digestion systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Comparison of POCIS passive samplers vs. composite water sampling: A case study.

    Science.gov (United States)

    Criquet, Justine; Dumoulin, David; Howsam, Michael; Mondamert, Leslie; Goossens, Jean-François; Prygiel, Jean; Billon, Gabriel

    2017-12-31

    The relevance of Polar Organic Chemical Integrative Samplers (POCIS) was evaluated for the assessment of concentrations of 46 pesticides and 19 pharmaceuticals in a small, peri-urban river with multi-origin inputs. Throughout the period of POCIS deployment, 24h-average water samples were collected automatically, and showed the rapid temporal evolution of concentrations of several micropollutants, as well as permitting the calculation of average concentrations in the water phase for comparison with those estimated from POCIS passive samplers. In the daily water samples, cyproconazol, epoxyconazol and imidacloprid showed high temporal variations with concentrations ranging from under the limit of detection up to several hundreds of ngL -1 . Erythromycin, cyprofloxacin and iopromide also increased rapidly up to tens of ngL -1 within a few days. Conversely, atrazine, caffeine, diclofenac, and to a lesser extent carbamazepine and sucralose, were systematically present in the water samples and showed limited variation in concentrations. For most of the substances studied here, the passive samplers gave reliable average concentrations between the minimal and maximal daily concentrations during the time of deployment. For pesticides, a relatively good correlation was clearly established (R 2 =0.89) between the concentrations obtained by POCIS and those gained from average water samples. A slight underestimation of the concentration by POCIS can be attributed to inappropriate sampling rates extracted from the literature and for our system, and new values are proposed. Considering the all data set, 75% of the results indicate a relatively good agreement between the POCIS and the average water samples concentration (values of the ratio ranging between 0,33 and 3). Note further that this agreement between these concentrations remains valid considering different sampling rates extracted from the literature. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Active Sampling Device for Determining Pollutants in Surface and Pore Water - the In Situ Sampler for Biphasic Water Monitoring

    Science.gov (United States)

    Supowit, Samuel D.; Roll, Isaac B.; Dang, Viet D.; Kroll, Kevin J.; Denslow, Nancy D.; Halden, Rolf U.

    2016-02-01

    We designed and evaluated an active sampling device, using as analytical targets a family of pesticides purported to contribute to honeybee colony collapse disorder. Simultaneous sampling of bulk water and pore water was accomplished using a low-flow, multi-channel pump to deliver water to an array of solid-phase extraction cartridges. Analytes were separated using either liquid or gas chromatography, and analysis was performed using tandem mass spectrometry (MS/MS). Achieved recoveries of fipronil and degradates in water spiked to nominal concentrations of 0.1, 1, and 10 ng/L ranged from 77 ± 12 to 110 ± 18%. Method detection limits (MDLs) were as low as 0.040-0.8 ng/L. Extraction and quantitation of total fiproles at a wastewater-receiving wetland yielded concentrations in surface water and pore water ranging from 9.9 ± 4.6 to 18.1 ± 4.6 ng/L and 9.1 ± 3.0 to 12.6 ± 2.1 ng/L, respectively. Detected concentrations were statistically indistinguishable from those determined by conventional, more laborious techniques (p > 0.2 for the three most abundant fiproles). Aside from offering time-averaged sampling capabilities for two phases simultaneously with picogram-per-liter MDLs, the novel methodology eliminates the need for water and sediment transport via in situ solid phase extraction.

  20. 9 CFR 318.9 - Samples of products, water, dyes, chemicals, etc., to be taken for examination.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Samples of products, water, dyes... ESTABLISHMENTS; REINSPECTION AND PREPARATION OF PRODUCTS General § 318.9 Samples of products, water, dyes, chemicals, etc., to be taken for examination. Samples of products, water, dyes, chemicals, preservatives...

  1. Detection of Flavobacterium psychrophilum from fish tissue and water samples by PCR amplification

    DEFF Research Database (Denmark)

    Wiklund, T.; Madsen, Lone; Bruun, Morten Sichlau

    2000-01-01

    Rainbow trout fry syndrome and cold-water disease, caused by Flavobacterium psychrophilum, are important diseases in farmed salmonids. Some of the presently available techniques for the detection of Fl. psychrophilum are either time consuming or lack sufficient sensitivity. In the present...... investigation, the possible detection of Fl. psychrophilum from fish tissue and water samples was examined using nested PCR with DNA probes against a sequence of the 16S rRNA genes. The DNA was extracted using Chelex(R) 100 chelating resin. The primers, which were tested against strains isolated from diseased...... to be more sensitive than agar cultivation of tissue samples from the brain of rainbow trout injected with Fl. psychrophilum. In non-sterile fresh water seeded with Fl. psychrophilum the detection limit of the PCR- assay was 1.7 cfu in the PCR tube, corresponding to 110 cfu ml(-1) water. The PCR...

  2. Using SPMDs for monitoring hydrophobic organic compounds in urban river water in Korea compared with using conventional water grab samples

    Science.gov (United States)

    Kim, Un-Jung; Kim, Hee Young; Alvarez, David A.; Lee, In-Seok; Oh, Jeong-Eun

    2014-01-01

    We aimed to verify the effectiveness of semi-permeablemembrane devices (SPMDs) formonitoring hydrophobic organic compounds, such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), that are not easy to detect using conventional grab samples (because of their low concentrations), in water.We used SPMDs and grab samples to monitor PCBs and PBDEs upstream and downstream of a sewage treatment plant (STP) in the Suyeong River in Busan, Korea. Concentrations in three different phases (freely dissolved, apparently dissolved, and particulate) were measured, to investigate the aquatic fate of PCBs and PBDEs. The freely dissolved (SPMD) concentrations were 2–3 times higher than the apparently dissolved and particulate phase (grab sample) concentrations. No meaningful relationships were found between the total PCB and PBDE concentrations of the grab sample and SPMD sample because of the different partitioning behaviors and detection frequencies of the individual chemicals. However, the summed concentrations of specific PCB and PBDE congeners (that were abundant in all samples) in the grab and SPMD samples correlated well (r2 = 0.7451 for PCBs 28 + 52 + 153, r2 = 0.9987 for PBDEs 28 + 47 + 99). The PBDE concentrations measured using SPMDs decreased with increasing distance from the STP, but no apparent dilution effect was found in the grab samples. Our results show that SPMDs could be used to support grab sampling for specific chemicals, or to trace chemical sources (such as STPs) to the aquatic environment.

  3. Direct determination of ammoniacal nitrogen in water samples using corona discharge ion mobility spectrometry.

    Science.gov (United States)

    Jafari, M T; Khayamian, T

    2008-09-15

    In this study, direct determination of ammoniacal nitrogen residues in water samples using corona discharge ion mobility spectrometry (CD-IMS) was investigated. Pyridine was used as an alternate reagent gas to enhance selectivity and sensitivity of the method. The results indicate that the limit of detection (LOD) was about 9.2x10(-3)mugmL(-1) and the linear dynamic range was obtained from 0.03 to 2.00mugmL(-1). The relative standard deviation was about 11%. Furthermore, this method was successfully applied to the direct determination of ammoniacal nitrogen in river and tap water samples and the results were compared with the Nessler method. The comparison of the results validates the potential of the proposed method as an alternative technique for the analysis of the ammoniacal nitrogen in water samples.

  4. The determination of levels of mercury, cadmium and lead in water samples from Naivasha area, Kenya

    International Nuclear Information System (INIS)

    Muigai, P.G.; Kamau, G.N.; Kinyua, A.M.

    1995-01-01

    The analysis of mercury, cadmium and lead in water samples from different environments (Lake Naivasha, River Malewa boreholes and Olkaria geothermal wells) in Naivasha region and their possible origins are reported. The levels of mercury and lead in the water samples were above the maximum permissible limits of 0.005 mg/1 and 0.1 mg/1 respectively, as stipulated by the WHO. On the other hand, 83.3% of the samples had cadmium levels above the maximum permissible limit of 0.01mg/1 in drinking water by WHO. The mercury and lead levels were also higher than those previously obtained from different regions of Kenya, while those for cadmium were within the corresponding range. Possible sources of elevated values were the geology of the surrounding area, sewage treatment works, use of phosphate rock fertilizers and lead fuels.(author)

  5. Detection by PCR of pathogenic protozoa in raw and drinkable water samples in Colombia.

    Science.gov (United States)

    Triviño-Valencia, Jessica; Lora, Fabiana; Zuluaga, Juan David; Gomez-Marin, Jorge E

    2016-05-01

    We evaluated the presence of DNA of Giardia, Toxoplasma, and Cryptosporidium by PCR, and of Giardia and Cryptosporidium genera by immunofluorescence antibody test (IFAT), in water samples, before, during, and after plant treatment for drinkable water. We applied this method in 38 samples of 10 l of water taken from each of the water treatment steps and in 8 samples taken at home (only for Toxoplasma PCR) in Quindio region in Colombia. There were 8 positive samples for Cryptosporidium parvum (21 %), 4 for Cryptosporidium hominis (10.5 %), 27 for Toxoplasma gondii (58.6 %), 2 for Giardia duodenalis assemblage A (5.2 %), and 5 for G. duodenalis assemblage B (13.1 %). By IFAT, 23 % were positive for Giardia and 21 % for Cryptosporidium. An almost perfect agreement was found between IFAT and combined results of PCR, by Kappa composite proportion analysis. PCR positive samples were significantly more frequent in untreated raw water for C. parvum (p = 0.02). High mean of fecal coliforms, high pH values, and low mean of chlorine residuals were strongly correlated with PCR positivity for G. duodenalis assemblage B. High pH value was correlated with PCR positivity for C. parvum. Phylogenetic analysis of DNA sequences was possible, showing water and human clinical sequences for Toxoplasma within the same phylogenetic group for B1 repeated sequence. PCR assay is complementary to IFAT assay for monitoring of protozoa in raw and drinkable water, enabling species identification and to look for phylogenetic analysis in protozoa from human and environmental sources.

  6. Monte Carlo simulation in quantitative determination of 137Cs in sand and water samples

    International Nuclear Information System (INIS)

    Ahuja, B.L.; Sharma, M.; Joshi, K.B.

    2002-01-01

    To understand the distribution of radionuclides in the high background area, one mainly needs to analyse sand, soil, water and other food stuff samples by gamma-spectroscopy. Due to interaction of photons emitted by these radionuclides within the sample, the underestimation of quantity of radionuclides in the sample cannot be ruled out. To overcome this situation, the Monte Carlo method to determine the effect of multiple scattering in Compton profiles has been extended to take better account of interaction of radiation with environmental samples. In this paper, we present the feasibility of Monte Carlo simulation in determining the absorption and multiple scattering of gamma-rays from 137 Cs radionuclides in the sand and water samples. It is seen that only 67 % and 90 % photons escaped from the sand and water respectively, can be detected by nuclear spectroscopy techniques. The high percentage of photoelectric absorption and Compton scattering of photons in these samples warrant the underestimation of quantitative determination of 137 Cs in these samples. (author)

  7. Quantitative Detection of Trace Malachite Green in Aquiculture Water Samples by Extractive Electrospray Ionization Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Xiaowei Fang

    2016-08-01

    Full Text Available Exposure to malachite green (MG may pose great health risks to humans; thus, it is of prime importance to develop fast and robust methods to quantitatively screen the presence of malachite green in water. Herein the application of extractive electrospray ionization mass spectrometry (EESI-MS has been extended to the trace detection of MG within lake water and aquiculture water, due to the intensive use of MG as a biocide in fisheries. This method has the advantage of obviating offline liquid-liquid extraction or tedious matrix separation prior to the measurement of malachite green in native aqueous medium. The experimental results indicate that the extrapolated detection limit for MG was ~3.8 μg·L−1 (S/N = 3 in lake water samples and ~0.5 μg·L−1 in ultrapure water under optimized experimental conditions. The signal intensity of MG showed good linearity over the concentration range of 10–1000 μg·L−1. Measurement of practical water samples fortified with MG at 0.01, 0.1 and 1.0 mg·L−1 gave a good validation of the established calibration curve. The average recoveries and relative standard deviation (RSD of malachite green in lake water and Carassius carassius fish farm effluent water were 115% (6.64% RSD, 85.4% (9.17% RSD and 96.0% (7.44% RSD, respectively. Overall, the established EESI-MS/MS method has been demonstrated suitable for sensitive and rapid (<2 min per sample quantitative detection of malachite green in various aqueous media, indicating its potential for online real-time monitoring of real life samples.

  8. Set Up of an Automatic Water Quality Sampling System in Irrigation Agriculture

    Science.gov (United States)

    Heinz, Emanuel; Kraft, Philipp; Buchen, Caroline; Frede, Hans-Georg; Aquino, Eugenio; Breuer, Lutz

    2014-05-01

    Climate change has already a large impact on the availability of water resources. Many regions in South-East Asia are assumed to receive less water in the future, dramatically impacting the production of the most important staple food: rice (Oryza sativa L.). Rice is the primary food source for nearly half of the World's population, and is the only cereal that can grow under wetland conditions. Especially anaerobic (flooded) rice fields require high amounts of water but also have higher yields than aerobic produced rice. In the past different methods were developed to reduce the water use in rice paddies, like alternative wetting and drying or the use of mixed cropping systems with aerobic (non-flooded) rice and alternative crops such as maize. A more detailed understanding of water and nutrient cycling in rice-based cropping systems is needed to reduce water use, and requires the investigation of hydrological and biochemical processes as well as transport dynamics at the field scale. New developments in analytical devices permit monitoring parameters at high temporal resolutions and at acceptable costs without much necessary maintenance or analysis over longer periods. Here we present a new type of automatic sampling set-up that facilitates in situ analysis of hydrometric information, stable water isotopes and nitrate concentrations in spatially differentiated agricultural fields. The system facilitates concurrent monitoring of a large number of water and nutrient fluxes (ground, surface, irrigation and rain water) in irrigated agriculture. For this purpose we couple an automatic sampling system with a Wavelength-Scanned Cavity Ring Down Spectrometry System (WS-CRDS) for stable water isotope analysis (δ2H and δ18O), a reagentless hyperspectral UV photometer for monitoring nitrate content and various water level sensors for hydrometric information. The whole system is maintained with special developed software for remote control of the system via internet. We

  9. Field portable mobile phone based fluorescence microscopy for detection of Giardia lamblia cysts in water samples

    Science.gov (United States)

    Ceylan Koydemir, Hatice; Gorocs, Zoltan; McLeod, Euan; Tseng, Derek; Ozcan, Aydogan

    2015-03-01

    Giardia lamblia is a waterborne parasite that causes an intestinal infection, known as giardiasis, and it is found not only in countries with inadequate sanitation and unsafe water but also streams and lakes of developed countries. Simple, sensitive, and rapid detection of this pathogen is important for monitoring of drinking water. Here we present a cost-effective and field portable mobile-phone based fluorescence microscopy platform designed for automated detection of Giardia lamblia cysts in large volume water samples (i.e., 10 ml) to be used in low-resource field settings. This fluorescence microscope is integrated with a disposable water-sampling cassette, which is based on a flow-through porous polycarbonate membrane and provides a wide surface area for fluorescence imaging and enumeration of the captured Giardia cysts on the membrane. Water sample of interest, containing fluorescently labeled Giardia cysts, is introduced into the absorbent pads that are in contact with the membrane in the cassette by capillary action, which eliminates the need for electrically driven flow for sample processing. Our fluorescence microscope weighs ~170 grams in total and has all the components of a regular microscope, capable of detecting individual fluorescently labeled cysts under light-emitting-diode (LED) based excitation. Including all the sample preparation, labeling and imaging steps, the entire measurement takes less than one hour for a sample volume of 10 ml. This mobile phone based compact and cost-effective fluorescent imaging platform together with its machine learning based cyst counting interface is easy to use and can even work in resource limited and field settings for spatio-temporal monitoring of water quality.

  10. Assessment of Heavy Metals in Water Samples of Certain Locations Situated Around Tumkur, Karnataka, India

    Directory of Open Access Journals (Sweden)

    C. Vijaya Bhaskar

    2010-01-01

    Full Text Available Surface water and groundwater samples of certain locations namely Kallambella, Bugudanahalli, Maidala, Honnudike, Kunigal, Kadaba and Hebbur, situated around Tumkur were assessed in the month of September 2008 for pH, EC and heavy metals Cd, Cu, Fe, Hg, Mn, Zn and Ni. The pH vales of surface waters were in alkaline range of 7.8-8.2 and are well within safe limits for crop production. The pH of ground- water was in the range of 7.6-8.4. The conductivity was in the range of 0.20-0.68 mS/cm and 0.34-2.44 mS/cm for surface and groundwaters respectively. High EC value of Kallambella groundwater accounts for its salinity. All surface waters except Honnudike and Hebbur samples contain low concentrations of these metals and are ideal for irrigation. Though the samples from Honnudike, Kadaba and Hebbur have high iron concentration, only Honnudike and Hebbur samples have exceeded the limit of 5 mg/L required for irrigation. In groundwaters the concentrations of all these heavy metals except copper are also well in permissible limits and suitable for drinking. Cu, Fe, Ni and Zn were detected in all the samples and found in the range of 0.094-0.131, 0.958-12.537, 0.020-0.036 and 0.082-1.139 mg/L respectively in surface waters and these are in the range of 0.132-0.142, 0.125-1.014, 0.028-0.036 and 0.003-0.037 mg/L in ground- waters. The elements cadmium, mercury and manganese are absent in all the samples.

  11. Development of a protocol for sampling and analysis of ballast water in Jamaica

    Directory of Open Access Journals (Sweden)

    Achsah A Mitchell

    2014-09-01

    Full Text Available The transfer of ballast by the international shipping industry has negatively impacted the environment. To design such a protocol for the area, the ballast water tanks of seven bulk cargo vessels entering a Jamaican port were sampled between January 28, 2010 and August 17, 2010. Vessels originated from five ports and used three main routes, some of which conducted ballast water exchange. Twenty-six preserved and 22 live replicate zooplankton samples were obtained. Abundance and richness were higher than at temperate ports. Exchange did not alter the biotic composition but reduced the abundance. Two of the live sample replicates, containing 31.67 and 16.75 viable individuals m-3, were non-compliant with the International Convention for the Control and Management of Ships’ Ballast Water and Sediments. Approximately 12% of the species identified in the ballast water were present in the waters nearest the port in 1995 and 11% were present in the entire bay in 2005. The protocol designed from this study can be used to aid the establishment of a ballast water management system in the Caribbean or used as a foundation for the development of further protocols.

  12. Semi-nested polymerase chain reaction for detection of toxigenic Vibrio cholerae from environmental water samples

    OpenAIRE

    Goel, Ajay Kumar; Bhadauria, Shweta; Kumar, Pramod; Kamboj, Dev V.; Singh, Lokendra

    2007-01-01

    A rapid and sensitive direct cell semi-nested PCR assay was developed for the detection of viable toxigenic V. cholerae in environmental water samples. The semi-nested PCR assay amplified cholera toxin (ctxA2B) gene present in the toxigenic V. cholerae. The detection sensitivity of direct cell semi-nested PCR was 2 × 103 CFU of V. cholerae whereas direct cell single-step PCR could detect 2 × 104 CFU of V. cholerae. The performance of the assay was evaluated using environmental water samples a...

  13. Glufosinate ammonium clean-up procedure from water samples using SPE

    Science.gov (United States)

    Tayeb M., A.; Ismail B., S.; Mardiana-Jansar, K.; Ta, Goh Choo; Agustar, Hani Kartini

    2015-09-01

    For the determination of glufosinate ammonium residue in soil and water samples, different solid phase extraction (SPE) sorbent efficiency was studied. Four different SPE sorbents i.e.: CROMABOND PS-H+, CROMABOND PS-OH-, ISOLUTE ENV+, Water Sep-Pak and OASIS HLB were used. Sample clean-up performance was evaluated using high performance liquid chromatography (Agilent 1220 infinity LC) with fluorescence detector. Detection of FMO-derivatives was done at λ ex = 260 nm and λ em= 310 nm. OASIS HLB column was the most suitable for the clean-up in view of the overall feasibility of the analysis.

  14. Water intakes and dietary sources of a nationally representative sample of Irish adults.

    Science.gov (United States)

    O'Connor, L; Walton, J; Flynn, A

    2014-12-01

    Despite evidence that even mild dehydration is associated with various morbidities, water intake estimates in free-living populations are lacking. The present study aimed to estimate water intakes and dietary sources in a nationally representative sample of the Irish adult population. A 4-day semi-weighed food record was used to collect dietary intake data from 1500 free-living adults aged 18-90 years in the Irish National Adult Nutrition Survey (NANS) (2008-2010) from which water intake was estimated. To enable fluid intake estimation, additional questions on how water and milk were consumed were incorporated. Total water intake was calculated as drinking water plus water from other beverages and food moisture. The mean (SD) daily total water intake for Irish adults was 2.31 (0.92) L day(-1) [males 2.52 (1.00) L day(-1) ; females 2.09 (0.79) L day(-1)]. Intakes were lowest in elderly adults, as well as in those with less education, a lower social class, less energy expenditure and a higher body mass index and body fat percentage. In total, 67% of water came from beverages and 33% came from food moisture. Alcoholic beverages and teas individually contributed to total water intake in amounts similar to the drinking water contribution. These data may be used as a foundation for further research in the area of the effect of under consumption of water on health outcomes to guide public health messages regarding adequate water intakes. © 2013 The British Dietetic Association Ltd.

  15. Adaptive Kalman Filter Based on Adjustable Sampling Interval in Burst Detection for Water Distribution System

    Directory of Open Access Journals (Sweden)

    Doo Yong Choi

    2016-04-01

    Full Text Available Rapid detection of bursts and leaks in water distribution systems (WDSs can reduce the social and economic costs incurred through direct loss of water into the ground, additional energy demand for water supply, and service interruptions. Many real-time burst detection models have been developed in accordance with the use of supervisory control and data acquisition (SCADA systems and the establishment of district meter areas (DMAs. Nonetheless, no consideration has been given to how frequently a flow meter measures and transmits data for predicting breaks and leaks in pipes. This paper analyzes the effect of sampling interval when an adaptive Kalman filter is used for detecting bursts in a WDS. A new sampling algorithm is presented that adjusts the sampling interval depending on the normalized residuals of flow after filtering. The proposed algorithm is applied to a virtual sinusoidal flow curve and real DMA flow data obtained from Jeongeup city in South Korea. The simulation results prove that the self-adjusting algorithm for determining the sampling interval is efficient and maintains reasonable accuracy in burst detection. The proposed sampling method has a significant potential for water utilities to build and operate real-time DMA monitoring systems combined with smart customer metering systems.

  16. A simplified method for low-level tritium measurement in the environmental water samples

    International Nuclear Information System (INIS)

    Sakuma, Yoichi; Yamanishi, Hirokuni; Ogata, Yoshimune

    2004-01-01

    Low level liquid scintillation counting took much time with a lot of doing to distill off the impurities in the sample water before mixing the sample with the liquid scintillation cocktail. In the light of it, we investigated the possibility of an alternative filtration method for sample purification. The tritium concentration in the environmental water has become very low, and the samples have to be treated by electrolysis enrichment with a liquid scintillation analyzer. Using the solid polymer electrolyte enriching device, there is no need to add neither any electrolyte nor the neutralization after the concentration. If we could replace the distillation process with the filtration, the procedure would be simplified very much. We investigated the procedure and we were able to prove that the reverse osmosis (RO) filtration was available. Moreover, in order to rationalize all through the measurement method, we examined the followings: (1) Improvement of the enriching apparatus. (2) Easier measurement of heavy water concentration using a density meter, instead of a mass spectrometer. The concentration of water samples was measured to determine the enrichment rate of tritium during the electrolysis enrichment. (author)

  17. UMTRA project water sampling and analysis plan, Falls City, Texas. Revision 1

    International Nuclear Information System (INIS)

    1995-09-01

    Planned, routine ground water sampling activities at the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site near Falls City, Texas, are described in this water sampling and analysis plan (WSAP). The following plan identifies and justifies the sampling locations, analytical parameters, and sampling frequency for the routine monitoring stations at the site. The ground water data are used for site characterization and risk assessment. The regulatory basis for routine ground water monitoring at UMTRA Project sites is derived from the US Environmental Protection Agency (EPA) regulations in 40 CFR Part 192. Sampling procedures are guided by the UMTRA Project standard operating procedures (SOP) (JEG, n.d.), the Technical Approach Document (TAD) (DOE, 1989), and the most effective technical approach for the site. The Falls City site is in Karnes County, Texas, approximately 8 miles [13 kilometers southwest of the town of Falls City and 46 mi (74 km) southeast of San Antonio, Texas. Before surface remedial action, the tailings site consisted of two parcels. Parcel A consisted of the mill site, one mill building, five tailings piles, and one tailings pond south of Farm-to-Market (FM) Road 1344 and west of FM 791. A sixth tailings pile designated Parcel B was north of FM 791 and east of FM 1344

  18. Single-stage epidural catheter lavage with posterior spondylodesis in lumbar pyogenic spondylodiscitis with multilevel epidural abscess formation.

    Science.gov (United States)

    Tschoeke, Sven K; Kayser, Ralph; Gulow, Jens; Hoeh, Nicolas von der; Salis-Soglio, Georg von; Heyde, Christoph

    2014-11-01

    Despite significant advances in the conservative management of pyogenic spondylodiscitis, consecutive instability, deformity, and/or neurologic compromise demands a prompt surgical intervention. However, in rare cases involving additional multilevel epidural abscess formation, the appropriate surgical strategy remains controversial. In this retrospective cohort analyses, we evaluated the efficacy of a single-stage posterior approach with the addition of a one-time multilevel epidural lavage via the surgically exposed interlaminar fenestration of the infected segment. From January 2009 through December 2010, 73 patients presenting pyogenic spondylodiscitis with instability of the lumbar spine were admitted. In all cases, the surgical strategy included a radical resection of the affected intervertebral disc and stabilization by intervertebral fusion using a titanium cage with autologous bone grafting in a level-dependent posterior approach with additional pedicle screw-and-rod instrumentation. In cases where multilevel abscess formation was evident, the standard surgical procedure was complemented by drainage and irrigation of the abscess from posterior by carefully advancing a soft infant feeding tube via the surgically exposed epidural space under fluoroscopic guidance. All patients received complementary oral antibiotic therapy for 12 weeks and were followed-up for a minimum of 12 months postoperatively. Ten patients (three male and seven female patients; mean age: 64.9 ± 10.9 years) presented with an additional lumbar epidural abscess extending beyond three levels proximal or distal to the infected disc. In all 10 patients the laboratory-chemical inflammatory parameters (leukocyte count, C-reactive protein) remained within the physiologic range after completing antibiotic therapy throughout the 1-year follow-up period. The plain radiographs and magnetic resonance imaging demonstrated solid fusion and the complete remission of the initial abscess formation after

  19. Rapid near-optimal trajectory generation and guidance law development for single-stage-to-orbit airbreathing vehicles

    Science.gov (United States)

    Calise, A. J.; Flandro, G. A.; Corban, J. E.

    1990-01-01

    General problems associated with on-board trajectory optimization, propulsion system cycle selection, and with the synthesis of guidance laws were addressed for an ascent to low-earth-orbit of an air-breathing single-stage-to-orbit vehicle. The NASA Generic Hypersonic Aerodynamic Model Example and the Langley Accelerator aerodynamic sets were acquired and implemented. Work related to the development of purely analytic aerodynamic models was also performed at a low level. A generic model of a multi-mode propulsion system was developed that includes turbojet, ramjet, scramjet, and rocket engine cycles. Provisions were made in the dynamic model for a component of thrust normal to the flight path. Computational results, which characterize the nonlinear sensitivity of scramjet performance to changes in vehicle angle of attack, were obtained and incorporated into the engine model. Additional trajectory constraints were introduced: maximum dynamic pressure; maximum aerodynamic heating rate per unit area; angle of attack and lift limits; and limits on acceleration both along and normal to the flight path. The remainder of the effort focused on required modifications to a previously derived algorithm when the model complexity cited above was added. In particular, analytic switching conditions were derived which, under appropriate assumptions, govern optimal transition from one propulsion mode to another for two cases: the case in which engine cycle operations can overlap, and the case in which engine cycle operations are mutually exclusive. The resulting guidance algorithm was implemented in software and exercised extensively. It was found that the approximations associated with the assumed time scale separation employed in this work are reasonable except over the Mach range from roughly 5 to 8. This phenomenon is due to the very large thrust capability of scramjets in this Mach regime when sized to meet the requirement for ascent to orbit. By accounting for flight path

  20. Removal of arsenic from ground water samples collected from West Bengal, India

    International Nuclear Information System (INIS)

    Ajith, Nicy; Swain, K.K.; Dalvi, Aditi A.; Verma, R.

    2015-01-01

    Arsenic contamination in ground water is one of the major concerns in many parts of the world including Bangladesh and India. Considering the high toxicity of arsenic, World Health Organization (WHO) has set a provisional guideline value of 10 μg L -1 for arsenic in drinking water. Several methods have been adopted for the removal of arsenic from drinking water. Most of the methods fail to remove As(III), the most toxic form of arsenic. An extra oxidative treatment step is essential for effective removal of total arsenic. Manganese dioxide (MnO 2 ) oxidizes As(III) to As(V). Removal of arsenic from water using manganese dioxide has been reported. During this work, removal of arsenic from ground water samples collected from arsenic contaminated area of West Bengal, India were carried out using MnO 2

  1. Metal quantification in water and sediment samples of billings reservoir by SR-TXRF

    International Nuclear Information System (INIS)

    Sampaio, Sergio Arnaud; Moreira, Silvana; Vives, Ana Elisa Sirito de

    2007-01-01

    Billings is the largest reservoir water of the metropolitan Sao Paulo area, with approximately 100km 2 of water. Its basin hydrographic occupies more than 500km 2 in six cities. It concentrates the largest industrial park of South America and only its margins are busy for almost a million inhabitants. The quality of its waters is, therefore, constant of concern of the whole society. In this work the Synchrotron Radiation Total Reflection X Ray Fluorescence (SR-TXRF) is applied for the identification and quantification of metals in waters and sediments of the Billings dam. A comparison of the levels of metals found with the maximum permissive limits established by the Brazilian legislation was made. The purpose of social context is to contribute for the preservation of the local springs and the rational use of its waters. For the field work they were chosen 19 collection points, included the margins and the central portion of the dam, in agreement with similar approaches the those adopted by the Company of Technology of Environmental Sanitation of Sao Paulo State (CETESB).The water and sediment samples, as well as the certified and standard samples, were analyzed at Brazilian Synchrotron Light Laboratory (LNLS), Campinas, SP, Brazil. Results indicate that the water and the sediments of the reservoir have concentrations above the legal limits. (author)

  2. Metal quantification in water and sediment samples of billings reservoir by SR-TXRF

    Energy Technology Data Exchange (ETDEWEB)

    Sampaio, Sergio Arnaud; Moreira, Silvana [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo]. E-mails: silvana@fec.unicamp.br; sergioarnaud@hotmail.com; Vives, Ana Elisa Sirito de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br

    2007-07-01

    Billings is the largest reservoir water of the metropolitan Sao Paulo area, with approximately 100km{sup 2} of water. Its basin hydrographic occupies more than 500km{sup 2} in six cities. It concentrates the largest industrial park of South America and only its margins are busy for almost a million inhabitants. The quality of its waters is, therefore, constant of concern of the whole society. In this work the Synchrotron Radiation Total Reflection X Ray Fluorescence (SR-TXRF) is applied for the identification and quantification of metals in waters and sediments of the Billings dam. A comparison of the levels of metals found with the maximum permissive limits established by the Brazilian legislation was made. The purpose of social context is to contribute for the preservation of the local springs and the rational use of its waters. For the field work they were chosen 19 collection points, included the margins and the central portion of the dam, in agreement with similar approaches the those adopted by the Company of Technology of Environmental Sanitation of Sao Paulo State (CETESB).The water and sediment samples, as well as the certified and standard samples, were analyzed at Brazilian Synchrotron Light Laboratory (LNLS), Campinas, SP, Brazil. Results indicate that the water and the sediments of the reservoir have concentrations above the legal limits. (author)

  3. Infrared thermometry and the crop water stress index. II. Sampling procedures and interpretation

    International Nuclear Information System (INIS)

    Gardner, B.R.; Nielsen, D.C.; Shock, C.C.

    1992-01-01

    Infrared thermometry can be a valuable research and production tool for detecting and quantifying water stress in plants, as shown by a large volume of published research. Users of infrared thermometers (IRT) should be aware of the many equipment, environmental, and plant factors influencing canopy temperature measured by an IRT. The purpose of this paper is to describe factors influencing measured plant temperature, outline sampling procedures that will produce reliable Crop Water Stress Index (CWSI) values, and offer interpretations of CWSI and plant temperatures relative to crop production and other water stress parameters by reviewing previously conducted research. Factors that are considered are IRT condition, configuration, and position; psychrometer location; wind speed; solar radiation; time of day; leaf area and orientation; and appropriate non-water-stressed baseline equation. Standard sampling and CWSI calculation procedures are proposed. Use of CWSI with crops varying in type of response to water stress is described. Previously conducted research on plant temperatures or CWSI is tabulated by crop and water stress parameters measured. The paper provides valuable information to assist interested users of IRTs in making reliable water stress measurements. (author)

  4. Determination of anionic concentrations in ground water samples using ion chromatography

    International Nuclear Information System (INIS)

    Prathibha, P.; Saradhi, I.V.; Pandit, G.G.; Puranik, V.D.

    2011-01-01

    Ion chromatography is a powerful separation technique for the quantitative measurement of anions in aqueous samples as well as in soil, sediment and air particulate samples leached in aqueous solutions. Ion chromatographic technique is developed by making use of suppressed ion conductivity detection (Small et.al.,1975) and it is a rapid multi ion analysis technique. The time, processing and effort required for the analysis of anions is much less compared to other techniques available such as ion selective electrode technique. In the present paper ground water samples collected around New BARC campus, Visakhapatnam are analyzed for anions using Ion chromatograph. The data generated will establish the current baseline status of the ionic contaminants in the study area. Groundwater samples are collected at 13 locations around BARC Vizag campus covering 30 km radius in September, 2009, April and July, 2010. The water samples include samples from hand pump and open wells in villages. The water samples are analyzed for fluoride, chloride, nitrate and sulphate using Metrohm make Ion chromatograph. The fluoride concentration in samples varied from 0.22 to 1.26 ppm, chloride from 18.7 to 810.9, nitrate from 1.34 to 378.5 ppm and sulphate from 13.29 to 250.69 ppm. No significant seasonal variations are observed in the samples collected from various locations except chloride at two locations. Ions Chromatograph is found to be a useful tool for simultaneous analysis of environmental samples with good accuracy where the concentrations of anions vary within an order of magnitude among them themselves. (author)

  5. Simple Modification of Karl-Fischer Titration Method for Determination of Water Content in Colored Samples

    OpenAIRE

    Eva Tavčar; Erika Turk; Samo Kreft

    2012-01-01

    The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a titration endpoint, appropriate for moisture determination of colored samples. The reaction takes p...

  6. Physiological response of wild dugongs (Dugong dugon) to out-of-water sampling for health assessment

    Science.gov (United States)

    Lanyon, Janet M.; Sneath, Helen L.; Long, Trevor; Bonde, Robert K.

    2010-01-01

    The dugong (Dugong dugon) is a vulnerable marine mammal with large populations living in urban Queensland waters. A mark-recapture program for wild dugongs has been ongoing in southern Queensland since 2001. This program has involved capture and in-water sampling of more than 700 dugongs where animals have been held at the water surface for 5 min to be gene-tagged, measured, and biopsied. In 2008, this program expanded to examine more comprehensively body condition, reproductive status, and the health of wild dugongs in Moreton Bay. Using Sea World's research vessel, captured dugongs were lifted onto a boat and sampled out-of-water to obtain accurate body weights and morphometrics, collect blood and urine samples for baseline health parameters and hormone profiles, and ultrasound females for pregnancy status. In all, 30 dugongs, including two pregnant females, were sampled over 10 d and restrained on deck for up to 55 min each while biological data were collected. Each of the dugongs had their basic temperature-heart rate-respiration (THR) monitored throughout their period of handling, following protocols developed for the West Indian manatee (Trichechus manatus). This paper reports on the physiological response of captured dugongs during this out-of-water operation as indicated by their vital signs and the suitability of the manatee monitoring protocols to this related sirenian species. A recommendation is made that the range of vital signs of these wild dugongs be used as benchmark criteria of normal parameters for other studies that intend to sample dugongs out-of-water.

  7. Method validation to determine total alpha beta emitters in water samples using LSC

    International Nuclear Information System (INIS)

    Al-Masri, M. S.; Nashawati, A.; Al-akel, B.; Saaid, S.

    2006-06-01

    In this work a method was validated to determine gross alpha and beta emitters in water samples using liquid scintillation counter. 200 ml of water from each sample were evaporated to 20 ml and 8 ml of them were mixed with 12 ml of the suitable cocktail to be measured by liquid scintillation counter Wallac Winspectral 1414. The lower detection limit by this method (LDL) was 0.33 DPM for total alpha emitters and 1.3 DPM for total beta emitters. and the reproducibility limit was (± 2.32 DPM) and (±1.41 DPM) for total alpha and beta emitters respectively, and the repeatability limit was (±2.19 DPM) and (±1.11 DPM) for total alpha and beta emitters respectively. The method is easy and fast because of the simple preparation steps and the large number of samples that can be measured at the same time. In addition, many real samples and standard samples were analyzed by the method and showed accurate results so it was concluded that the method can be used with various water samples. (author)

  8. The installation of a multiport ground-water sampling system in the 300 Area

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, T.J.

    1989-06-01

    In 1988, the Pacific Northwest Laboratory installed a multiport groundwater sampling system in well 399-1-20, drilled north of the 300 Area on the Hanford Site in southwestern Washington State. The purpose of installing the multiport system is to evaluate methods of determining the vertical distribution of contaminants and hydraulic heads in ground water. Well 399-1-20 is adjacent to a cluster of four Resource Conservation and Recovery Act (RCRA) ground-water monitoring wells. This proximity makes it possible to compare sampling intervals and head measurements between the multiport system and the RCRA monitoring wells. Drilling and installation of the multiport system took 42 working days. Six sampling ports were installed in the upper unconfined aquifer at depths of approximately 120, 103, 86, 74, 56, and 44 feet. The locations of the sampling ports were determined by the hydrogeology of the area and the screened intervals of adjacent ground-water monitoring wells. The system was installed by backfilling sand around the sampling ports and isolating the ports with bentonite seals. The method proved adequate. For future installation, however, development and evaluation of an alternative method is recommended. In the alternative method suggested, the multiport system would be placed inside a cased and screened well, using packers to isolate the sampling zones. 4 refs., 8 figs., 1 tab.

  9. {sup 222}Rn determination in water and brine samples using liquid scintillation spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Thiago C.; Oliveira, Arno H., E-mail: oliveiratco2010@gmail.com [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte (Brazil). Departamento de Engenharia Nuclear; Monteiro, Roberto P.G.; Moreira, Rubens M., E-mail: rpgm@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN-CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Liquid scintillation spectrometry (LSC) is the most common technique used for {sup 222}Rn determination in environmental aqueous sample. In this study, the performance of water-miscible (Ultima Gold AB) and immiscible (Optiscint) liquid scintillation cocktails has been compared for different matrices. {sup 241}Am, {sup 90}Sr and {sup 226}Ra standard solutions were used for LSC calibration. {sup 214}Po region was defined as better for both cocktails. Counting efficiency of 76 % and optimum PSA level of 95 for Ultima Gold AB cocktail, and counting efficiency of 82 % and optimum PSA level of 85 for Optiscint cocktail were obtained. Both cocktails showed similar results when applied for {sup 222}Rn activity determination in water and brine samples. However the Optiscint is recommended due to its quenching resistance. Limit of detection of 0.08 and 0.06 Bq l{sup -1} were obtained for water samples using a sample:cocktail ratio of 10:12 mL for Ultima Gold AB and Optiscint cocktails, respectively. Limit of detection of 0.08 and 0.04 Bq l{sup -1} were obtained for brine samples using a sample:cocktail ratio of 8:12 mL for Ultima Gold AB and Optiscint cocktails, respectively. (author)

  10. The Evaluation of Aluminum Content for ‎Different Water Samples from Some Iraqi Cities

    Directory of Open Access Journals (Sweden)

    Hashim Haneen Kareem

    2017-12-01

    Full Text Available In this study, different samples of water are collected  from different provinces including,  (Babylon , Maysan , Al kut  which were ( river water ,drainage water and drinking water. Water sampling was during the month of February 2014. The chemical properties of these samples have been determined  including ( pH - Ec-Ca-Mg-K - Na - HCO3 and CO3 as well as measured aluminum for each sample and the results were as follows ,it was founded that    Ec ranged  from(  1 .101 - 5.39 ms / cm  ,higher  value found in Babylon for drainage water and lower value found in Al kut for drinking water . The values ​​of pH are ranged  from( 7.65 -8.26 and the values ​​for  are ranged from (5.26-29.91 meq / L and the values ​​of  are ranged from (0.19-1.53 meq / L and values ​​for Cl ranged from (15 - 31 meq / L and the values ​​for CO3 ranged from (0 - 0.1 meq / L and the values ​​for HCO3 ranging from (1.6-7 meq / L and the values ​​for Ca ranging from (3.4-11.8 meq / L and the values ​​for Mg ranging from (4.4-19.4 meq / L and the values ​​for (Al is very high and ranging from (0.640 to 0.647 ppm, and compared the results with standard specification of Iraq

  11. Membrane solid-phase extraction: Field application for isolation of polycyclic aromatic hydrocarbons from water samples

    International Nuclear Information System (INIS)

    Furlong, E.T.; Koleis, J.C.; Gates, P.M.

    1995-01-01

    Solid-phase extraction (SPE) membranes (M-SPE) were used to isolate microgram-per-liter to nanogram-per-liter quantities of polycyclic aromatic hydrocarbons (PAH) in 4- to 8-liter ground-water samples from a crude-oil-contaminated ground-water site near Bemidji, Minnesota. The M-SPE method was evaluated (1) under laboratory conditions using reagent water fortified with individual PAH at 1.23 micrograms per liter, and (2) at the Bemidji site. At the site, ground-water samples were processed and PAH isolated using a M-SPE system connected directly to the well pump. Following sample isolation, all M-SPE samples were extracted using dichloromethane and analyzed by gas chromatography-mass spectrometry with selected-ion monitoring. Operationally, the M-SPE method provided a simple means to isolate PAH on site at the wellhead, particularly for anoxic water samples. Acceptable recoveries, ranging from 56 to over 100 percent, were observed for lower molecular weight PAH (naphthalene to pyrene) using the M-SPE method. Recoveries using M-SPE were somewhat lower, but reproducible, for higher molecular weight PAH (chrysene to benzo[ghi]perylene), ranging from 18 to 56 percent. M-SPE provides the capability to collect and field isolate PAH from a sufficiently large number of samples to identify environmental chemical processes occurring at individual compound concentrations of 50 to 1,200 nanograms per liter. Using M-SPE, the potential for facilitated transport of PAH by in situ-derived dissolved organic carbon (DOC) was evaluated at the site. Plots comparing DOC and PAH concentrations indicate that PAH concentrations increase exponentially with linear increases in DOC concentrations

  12. Water Quality Sampling Locations Along the Shoreline of the Columbia River, Hanford Site, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Robert E.; Patton, Gregory W.

    2009-12-14

    As environmental monitoring evolved on the Hanford Site, several different conventions were used to name or describe location information for various sampling sites along the Hanford Reach of the Columbia River. These methods range from handwritten descriptions in field notebooks to the use of modern electronic surveying equipment, such as Global Positioning System receivers. These diverse methods resulted in inconsistent archiving of analytical results in various electronic databases and published reports because of multiple names being used for the same site and inaccurate position data. This document provides listings of sampling sites that are associated with groundwater and river water sampling. The report identifies names and locations for sites associated with sampling: (a) near-river groundwater using aquifer sampling tubes; (b) riverbank springs and springs areas; (c) pore water collected from riverbed sediment; and (d) Columbia River water. Included in the listings are historical names used for a particular site and the best available geographic coordinates for the site, as of 2009. In an effort to create more consistency in the descriptive names used for water quality sampling sites, a naming convention is proposed in this document. The convention assumes that a unique identifier is assigned to each site that is monitored and that this identifier serves electronic database management requirements. The descriptive name is assigned for the convenience of the subsequent data user. As the historical database is used more intensively, this document may be revised as a consequence of discovering potential errors and also because of a need to gain consensus on the proposed naming convention for some water quality monitoring sites.

  13. Solvent-assisted dispersive solid-phase extraction: A sample preparation method for trace detection of diazinon in urine and environmental water samples.

    Science.gov (United States)

    Aladaghlo, Zolfaghar; Fakhari, Alireza; Behbahani, Mohammad

    2016-09-02

    In this research, a sample preparation method termed solvent-assisted dispersive solid-phase extraction (SA-DSPE) was applied. The used sample preparation method was based on the dispersion of the sorbent into the aqueous sample to maximize the interaction surface. In this approach, the dispersion of the sorbent at a very low milligram level was received by inserting a solution of the sorbent and disperser solvent into the aqueous sample. The cloudy solution created from the dispersion of the sorbent in the bulk aqueous sample. After pre-concentration of the diazinon, the cloudy solution was centrifuged and diazinon in the sediment phase dissolved in ethanol and determined by gas chromatography-flame ionization detector. Under the optimized conditions (pH of solution=7.0, Sorbent: benzophenone, 2%, Disperser solvent: ethanol, 500μL, Centrifuge: centrifuged at 4000rpm for 3min), the method detection limit for diazinon was 0.2, 0.3, 0.3 and 0.3μgL(-1) for distilled water, lake water, waste water and urine sample, respectively. Furthermore, the pre-concentration factor was 363.8, 356.1, 360.7 and 353.38 in distilled water, waste water, lake water and urine sample, respectively. SA-DSPE was successfully used for trace monitoring of diazinon in urine, lake and waste water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Gross-beta activity in ground water: natural sources and artifacts of sampling and laboratory analysis

    Science.gov (United States)

    Welch, Alan H.

    1995-01-01

    Gross-beta activity has been used as an indicator of beta-emitting isotopes in water since at least the early 1950s. Originally designed for detection of radioactive releases from nuclear facilities and weapons tests, analysis of gross-beta activity is widely used in studies of naturally occurring radioactivity in ground water. Analyses of about 800 samples from 5 ground-water regions of the United States provide a basis for evaluating the utility of this measurement. The data suggest that measured gross-beta activities are due to (1) long-lived radionuclides in ground water, and (2) ingrowth of beta-emitting radionuclides during holding times between collection of samples and laboratory measurements.Although40K and228Ra appear to be the primary sources of beta activity in ground water, the sum of40K plus228Ra appears to be less than the measured gross-beta activity in most ground-water samples. The difference between the contribution from these radionuclides and gross-beta activity is most pronounced in ground water with gross-beta activities > 10 pCi/L, where these 2 radionuclides account for less than one-half the measured ross-beta activity. One exception is groundwater from the Coastal Plain of New Jersey, where40K plus228Ra generally contribute most of the gross-beta activity. In contrast,40K and228Ra generally contribute most of beta activity in ground water with gross-beta activities 10 pCi/L. Ingrowth of beta-emitting progeny of238U, specifically234Pa and234Th, contributes much of the measured gross-beta activity in ground water from 4 of the 5 areas studied. Consequently, gross-beta activity measurements commonly overestimate the abundance of beta-emitting radionuclides actually present in ground water. Differing sample holding times before analysis lead to differing amounts of ingrowth of the two progeny. Therefore, holding times can affect observed gross-beta measurements, particularly in ground water with238U activities that are moderate to high

  15. Report on water quality, sediment and water chemistry data for water and sediment samples collected from source areas to Melton Hill and Watts Bar reservoirs

    International Nuclear Information System (INIS)

    Tomaszewski, T.M.; Bruggink, D.J.; Nunn, D.L.

    1995-01-01

    Contamination of surface water and sediments in the Clinch River and Watts Bar Reservoir (CR/WBR) system as a result of past and present activities by the US Department of Energy (DOE) on the Oak Ridge Reservation (ORR) and also activities by non-ORR facilities are being studied by the Clinch River Environmental Restoration Program (CR-ERP). Previous studies have documented the presence of heavy metals, organics, and radionuclides in the sediments of reservoirs in the vicinity. In support of the CR-ERP, during the summer of 1991, TVA collected and evaluated water and sediment samples from swimming areas and municipal water intakes on Watts Bar Reservoir, Melton Hill Reservoir and Norris Reservoir, which was considered a source of less-contaminated reference or background data. Despite the numerous studies, until the current work documented by this report, relatively few sediment or water samples had been collected by the CR-ERP in the immediate vicinity of contaminant point sources. This work focused on water and sediment samples taken from points immediately downstream from suspected effluent point sources both on and off the ORR. In August and September, 1994, TVA sampled surface water and sediment at twelve locations in melton Hill and Watts Bar Reservoirs

  16. Fast and effective determination of strontium-90 in high volumes water samples

    International Nuclear Information System (INIS)

    Basarabova, B.; Dulanska, S.

    2014-01-01

    A simple and fast method was developed for determination of 90 Sr in high volumes of water samples from vicinity of nuclear power facilities. Samples were taken from the environment near Nuclear Power Plants in Jaslovske Bohunice and Mochovce in Slovakia. For determination of 90 Sr was used solid phase extraction using commercial sorbent Analig R Sr-01 from company IBC Advanced Technologies, Inc.. Determination of 90 Sr was performed with dilute solution of HNO 3 (1.5-2 M) and also tested in base medium with NaOH. For elution of 90 Sr was used eluent EDTA with pH in range 8-9. To achieve fast determination, automation was applied, which brings significant reduction of separation time. Concentration of water samples with evaporation was not necessary. Separation was performed immediately after filtration of analyzed samples. The aim of this study was development of less expensive, time unlimited and energy saving method for determination of 90 Sr in comparison with conventional methods. Separation time for fast-flow with volume of 10 dm 3 of water samples was 3.5 hours (flow-rate approximately 3.2 dm 3 / 1 hour). Radiochemical strontium yield was traced by using radionuclide 85 Sr. Samples were measured with HPGe detector (High-purity Germanium detector) at energy E φ = 514 keV. By using Analig R Sr-01 yields in range 72 - 96 % were achieved. Separation based on solid phase extraction using Analig R Sr-01 employing utilization of automation offers new, fast and effective method for determination of 90 Sr in water matrix. After ingrowth of yttrium samples were measured by Liquid Scintillation Spectrometer Packard Tricarb 2900 TR with software Quanta Smart. (authors)

  17. Measuring pesticides in surface waters - continuous versus event-based sampling design

    Science.gov (United States)

    Eyring, J.; Bach, M.; Frede, H.-G.

    2009-04-01

    Monitoring pesticides in surface waters is still a work- and cost-intensive procedure. Therefore, studies are normally carried out with a low monitoring frequency or with only a small selection of substances to be analyzed. In this case, it is not possible to picture the high temporal variability of pesticide concentrations, depending on application dates, weather conditions, cropping seasons and other factors. In 2007 the Institute of Landscape Ecology and Resource Management at Giessen University implemented a monitoring program during two pesticide application periods aiming to produce a detailed dataset of pesticide concentration for a wide range of substances, and which would also be suitable for the evaluation of catchment-scale pesticide exposure models. The Weida catchment in Thuringia (Eastern Germany) was selected as study area due to the availability of detailed pesticide application data for this region. The samples were taken from the river Weida at the gauge Zeulenroda, where it flows into a drinking water reservoir. The catchment area is 102 km². 67% of the area are in agricultural use, the main crops being winter wheat, maize, winter barley and winter rape. Dominant soil texture classes are loamy sand and loamy silt. About one third of the agricultural area is drained. The sampling was carried out in cooperation with the water supply agency of Thuringia (Fernwasserversorgung Thueringen). The sample analysis was done by the Institute of Environmental Research at Dortmund University. Two sampling schemes were carried out using two automatic samplers: continuous sampling with composite samples bottled two times per week and event-based sampling triggered by a discharge threshold. 53 samples from continuous sampling were collected. 19 discharge events were sampled with 45 individual samples (one to six per event). 34 pesticides and two metabolites were analyzed. 21 compounds were detected, nine of which having concentrations above the drinking water

  18. Evaluation of HDPE water sample bottles and PVC sampler tubing used in herbicide dissipation studies.

    Science.gov (United States)

    J. B. Fischer; J. L. Michael; H. L. Gibbs

    2009-01-01

    The recovery of six herbicides (triclopyr, triclopyr ester, sulfometuron methyl, metsulfuron methyl, imazapyr, and hexazinone) was evaluated in two stream water samples, one from Weogufka Creek in the Alabama Piedmont and one from a stagnant stream in the Escambia Experimental Forest near Florida. Simulated field study conditions were...

  19. Supplement to the UMTRA Project water sampling and analysis plan, Maybell, Colorado

    International Nuclear Information System (INIS)

    1995-09-01

    This water sampling and analysis plan (WSAP) supplement supports the regulatory and technical basis for water sampling at the Maybell, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project site, as defined in the 1994 WSAP document for Maybell (DOE, 1994a). Further, this supplement serves to confirm our present understanding of the site relative to the hydrogeology and contaminant distribution as well as our intention to continue to use the sampling strategy as presented in the 1994 WSAP document for Maybell. Ground water and surface water monitoring activities are derived from the US Environmental Protection Agency regulations in 40 CFR Part 192 (1994) and 60 CFR 2854 (1 995). Sampling procedures are guided by the UMTRA Project standard operating procedures (JEG, n.d.), the Technical Approach Document (DOE, 1989), and the most effective technical approach for the site. Additional site-specific documents relevant to the Maybell site are the Maybell Baseline Risk Assessment (currently in progress), the Maybell Remedial Action Plan (RAP) (DOE, 1994b), and the Maybell Environmental Assessment (DOE, 1995)

  20. HYDROLYSIS OF MTBE TO TBA IN GROUND WATER SAMPLES WITH HYDROCHLORIC ACID

    Science.gov (United States)

    Conventional sampling and analytical protocols have poor sensitivity for fuel oxygenates that are alcohols, such as tert-butyl alcohol (TBA). Because alcohols are miscible or highly soluble in water, alcohols are not efficiently transferred to the gas chromatograph for analysis....

  1. Laboratory performance study for passive sampling of nonpolar chemicals in water

    NARCIS (Netherlands)

    Booij, Kees; Smedes, Foppe; Crum, Steven

    2017-01-01

    Two laboratory performance studies with 21 and 11 participants were carried out for passive sampling of nonpolar chemicals in water, using silicone samplers that were deployed for 7 wk and 13 wk at 2 river sites in the Netherlands. Target analytes were polychlorinated biphenyls, polycyclic aromatic

  2. RA-226 concentration in water samples near uranium mines and in marine fishes

    International Nuclear Information System (INIS)

    Porntepkasemsan, B.

    1987-11-01

    Radium-226 and calcium were measured in water samples from the vicinity of three uranium mines and in fish samples collected from Puget sound, Washington State. The radium content of the samples were below the maximum permissible concentration 3 pCi/L for drinking water recommended by the Public Health Service and U.S. Environmental Protection Agency. The mean value of Ra-226 in water was 0.428 pCi/L and ranged from 0.043 to 1.552 pCi/L, whereas calcium content ranged from 3.0 to 190.0 mg/L. Ra-226 concentrations and calcium content in whole fish were 0.833-20.328 pCi/kg wet wt. and 114.1-259.3 mg/g ash, respectively. Results of the study indicated that Ra-226 concentration in water was correlated with calcium concentration but that this correlation was not observed in fish sample except English sole

  3. Innovative sampling and extraction methods for the determination of nonsteroidal anti-inflammatory drugs in water.

    Science.gov (United States)

    Tanwar, Shivani; Di Carro, Marina; Magi, Emanuele

    2015-03-15

    Two different innovative approaches were used for the determination of nonsteroidal anti-inflammatory drugs (NSAIDs) in water: stir bar sorptive extraction (SBSE) and passive sampling, followed by electrospray ionization liquid chromatography-tandem mass spectrometry. SBSE was developed by comparing EG-Silicone and PDMS stir bars and optimizing main parameters to attain high preconcentration. Quantitative analysis was carried out by mass spectrometry in negative ionization mode and multiple reaction monitoring. The SBSE-LC-MS/MS method provided satisfactory figures of merit with LOD (7.5-71 ng L(-1)) and LOQ (22.5-213 ng L(-1)). The developed method was successfully applied to real samples collected from river water and wastewater effluents. The obtained results showed the presence of all analytes at trace levels, in a wide range of concentrations. The passive sampling approach was carried out by using Polar Organic Chemical Integrative Sampler (POCIS); samplers were deployed for 15 days in river and tap water, allowing to detect analytes at ultra-trace levels. Time-Weighted Average concentration of NSAIDs in river water was estimated in the range 0.33-0.46 ng L(-1), using the sampling rates previously obtained by means of a simple calibration system. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Sample preparation for combined chemical analysis and bioassay application in water quality assessment

    NARCIS (Netherlands)

    Kolkman, A.; Schriks, M.; Brand, W; Bäuerlein, P.S.; van der Kooi, M.M.E.; van Doorn, R.H.; Emke, E.; Reus, A.; van der Linden, S.; de Voogt, P.; Heringa, M.B.

    2013-01-01

    The combination of in vitro bioassays and chemical screening can provide a powerful toolbox to determine biologically relevant compounds in water extracts. In this study, a sample preparation method is evaluated for the suitability for both chemical analysis and in vitro bioassays. A set of 39

  5. Ionic liquids for the passive sampling of sulfonamides from water-applicability and selectivity study.

    Science.gov (United States)

    Męczykowska, Hanna; Kobylis, Paulina; Stepnowski, Piotr; Caban, Magda

    2017-06-01

    Ionic liquids (ILs) are new-generation, non-volatile solvents which are designable, and their structure may be specifically adjusted to the current application needs. Therefore, it is possible to create and apply ILs which efficiently and selectively extract various analytes from different matrices. It has already been examined that ILs may be applied as receiving phases in passive sampling for the long-term water monitoring of PAHs and pharmaceuticals in water. In this paper, the concept of passive sampling with ILs (PASSIL applied as receiving phases) was continued and developed using phosphonium-, imidazolium-, and morpholinium-cation-based ILs. The target group of analytes was pharmaceuticals which represent one of the most common categories of water contaminants. Fourteen-day-long extractions using various ILs were performed in stirred conditions at a constant temperature (20 °C). The best extraction efficiency was achieved for trihexyl(tetradecyl)phosphonium dicyanamide ([P666-14][N(CN) 2 ]). For this preliminary calibration, the sampling rates were calculated for each sulfonamide. Once again, selectivity was observed in passive sampling using [P666-14][N(CN) 2 ]. Therefore, PASSIL is seen as a very promising method for pharmaceutical monitoring in water.

  6. Measurement of the tritium concentration in the fractionated distillate from environmental water samples.

    Science.gov (United States)

    Atkinson, Robert; Eddy, Teresa; Kuhne, Wendy; Jannik, Tim; Brandl, Alexander

    2014-09-01

    Standard procedures for the measurement of tritium in water samples often require distillation of an appropriate sample aliquot. This distillation process may result in a fractionation of tritiated water and regular light water due to the vapor pressure isotope effect, introducing either a bias or an additional contribution to the total tritium measurement uncertainty. The current study investigates the relative change in vapor pressure isotope effect in the course of the distillation process, distinguishing it from and extending previously published measurements. The separation factor as a quantitative measure of the vapor pressure isotope effect is found to assume values of 1.04 ± 0.036, 1.05 ± 0.026, and 1.07 ± 0.038, depending on the vigor of the boiling process during distillation of the sample. A lower heat setting in the experimental setup, and therefore a less vigorous boiling process, results in a larger value for the separation factor. For a tritium measurement in water samples where the first 5 mL are discarded, the tritium concentration could be underestimated by 4-7%. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. [Water perception and utilization in a sample of students in the province of Viterbo].

    Science.gov (United States)

    Damiani, G; Russo, N; Federico, B; Spera, D; Gasperini, L; Magrini, A; Ricciardi, G

    2003-01-01

    Nowadays water quality is certainly one of the issues of major concern. Control on waterway considerably involves public hygiene services and represents a prevention activity and a measure of public health safety, which often is unknown to the population. For this reason the Public Hygiene Service of Viterbo L.H.U. (Local Health Unit) in collaboration with the Institute of Hygiene of the Catholic University of Rome carried out a survey to evaluate perception towards tap water quality in a sample of students. During the last decade tap and mineral water consumption habits turned out to be constant. The great majority of students reported to use widely mineral water at home; mineral water consumption was high regardless of social class. Since our investigation found a large use of mineral water in this town, the L.H.U. could intervene to modify these attitudes, starting up with an education campaign of the population: tap water is indeed subject to quality controls with a higher frequency compared to mineral water.

  8. 226Ra, 232Th and 40K analysis in water samples from Assiut, Egypt

    International Nuclear Information System (INIS)

    El-Gamal, H.; Abdel Mageed, A.I.; El-Attar, A.L; Abdel Hamid, M.

    2013-01-01

    The activity concentrations of 226 Ra, 232 Th and 40 K were determined in water samples, using 2”x 2” NaI(Tl) scintillation detector. Water activity ranges from 0.07 to 0.59 Bq L−1 for 226 Ra, 0.05 to 0.37 Bq L−1 for 232 Th and 3.25 to 8.72 Bq L−1 for 40 K with mean values of 2.64, 2.22 and 119.50 Bq L−1, respectively. As far as the measured gamma radionuclides is concerned, the mean annual effective doses for all analyzed samples of water are in the range of 0.02–0.08, 0.03-0.17 and 0.03-0.10 mSv yr -1 for infants, children and adults, respectively, all being lower than the reference level of the committed effective dose recommended by the WHO.

  9. Letter Report: Stable Hydrogen and Oxygen Isotope Analysis of B-Complex Perched Water Samples

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Brady D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moran, James J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nims, Megan K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Saunders, Danielle L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-04-13

    Fine-grained sediments associated with the Cold Creek Unit at Hanford have caused the formation of a perched water aquifer in the deep vadose zone at the B Complex area, which includes waste sites in the 200-DV-1 Operable Unit and the single-shell tank farms in Waste Management Area B-BX-BY. High levels of contaminants, such as uranium, technetium-99, and nitrate, make this aquifer a continuing source of contamination for the groundwater located a few meters below the perched zone. Analysis of deuterium (2H) and 18-oxygen (18O) of nine perched water samples from three different wells was performed. Samples represent time points from hydraulic tests performed on the perched aquifer using the three wells. The isotope analyses showed that the perched water had δ2H and δ18O ratios consistent with the regional meteoric water line, indicating that local precipitation events at the Hanford site likely account for recharge of the perched water aquifer. Data from the isotope analysis can be used along with pumping and recovery data to help understand the perched water dynamics related to aquifer size and hydraulic control of the aquifer in the future.

  10. An Energy Efficient Adaptive Sampling Algorithm in a Sensor Network for Automated Water Quality Monitoring.

    Science.gov (United States)

    Shu, Tongxin; Xia, Min; Chen, Jiahong; Silva, Clarence de

    2017-11-05

    Power management is crucial in the monitoring of a remote environment, especially when long-term monitoring is needed. Renewable energy sources such as solar and wind may be harvested to sustain a monitoring system. However, without proper power management, equipment within the monitoring system may become nonfunctional and, as a consequence, the data or events captured during the monitoring process will become inaccurate as well. This paper develops and applies a novel adaptive sampling algorithm for power management in the automated monitoring of the quality of water in an extensive and remote aquatic environment. Based on the data collected on line using sensor nodes, a data-driven adaptive sampling algorithm (DDASA) is developed for improving the power efficiency while ensuring the accuracy of sampled data. The developed algorithm is evaluated using two distinct key parameters, which are dissolved oxygen (DO) and turbidity. It is found that by dynamically changing the sampling frequency, the battery lifetime can be effectively prolonged while maintaining a required level of sampling accuracy. According to the simulation results, compared to a fixed sampling rate, approximately 30.66% of the battery energy can be saved for three months of continuous water quality monitoring. Using the same dataset to compare with a traditional adaptive sampling algorithm (ASA), while achieving around the same Normalized Mean Error (NME), DDASA is superior in saving 5.31% more battery energy.

  11. An Energy Efficient Adaptive Sampling Algorithm in a Sensor Network for Automated Water Quality Monitoring

    Directory of Open Access Journals (Sweden)

    Tongxin Shu

    2017-11-01

    Full Text Available Power management is crucial in the monitoring of a remote environment, especially when long-term monitoring is needed. Renewable energy sources such as solar and wind may be harvested to sustain a monitoring system. However, without proper power management, equipment within the monitoring system may become nonfunctional and, as a consequence, the data or events captured during the monitoring process will become inaccurate as well. This paper develops and applies a novel adaptive sampling algorithm for power management in the automated monitoring of the quality of water in an extensive and remote aquatic environment. Based on the data collected on line using sensor nodes, a data-driven adaptive sampling algorithm (DDASA is developed for improving the power efficiency while ensuring the accuracy of sampled data. The developed algorithm is evaluated using two distinct key parameters, which are dissolved oxygen (DO and turbidity. It is found that by dynamically changing the sampling frequency, the battery lifetime can be effectively prolonged while maintaining a required level of sampling accuracy. According to the simulation results, compared to a fixed sampling rate, approximately 30.66% of the battery energy can be saved for three months of continuous water quality monitoring. Using the same dataset to compare with a traditional adaptive sampling algorithm (ASA, while achieving around the same Normalized Mean Error (NME, DDASA is superior in saving 5.31% more battery energy.

  12. High-resolution passive sampling of dissolved methane in the water column of lakes in Greenland

    Science.gov (United States)

    Goldman, A. E.; Cadieux, S. B.; White, J. R.; Pratt, L. M.

    2013-12-01

    Arctic lakes are important participants in the global carbon cycle, releasing methane in a warming climate and contributing to a positive feedback to climate change. In order to yield detailed methane budgets and understand the implications of warming on methane dynamics, high-resolution profiles revealing methane behavior within the water column need to be obtained. Single day sampling using disruptive techniques has the potential to result in biases. In order to obtain high-resolution, undisturbed profiles of methane concentration and isotopic composition, this study evaluates a passive sampling method over a multi-day equilibration period. Selected for this study were two small lakes (Gatos Research Methane Carbon Isotope Analyzer. PDB sampling and pump sampling resulted in statistically similar concentrations (R2=0.89), ranging from 0.85 to 135 uM from PDB and 0.74 to 143 uM from pump sampling. In anoxic waters of the lake, where concentrations were high enough to yield robust isotopic results on the LGR MCIA, δ13C were also similar between the two methods, yielding -73‰ from PDB and -74‰ from pump sampling. Further investigation will produce results for a second lake and methane carbon and hydrogen isotopic composition for both lakes. Preliminary results for this passive sampling method are promising. We envision the use of this technique in future studies of dissolved methane and expect that it will provide a more finely resolved vertical profile, allowing for a more complete understanding of lacustrine methane dynamics.

  13. Results of elemental analyses of water and waterborne sediment samples from the Fairbanks NTMS quadrangle, Alaska

    International Nuclear Information System (INIS)

    Sharp, R.R. Jr.; Aamodt, P.L; Hill, D.E.

    1979-04-01

    During the late spring and then again in late summer, 1977, lake and stream water and bottom sediment samples were collected at a nominal density of one location every 16 km 2 from throughout the approximate 16,500-km 2 area of the Fairbanks NTMS quadrangle, Alaska. These samples were collected using standard procedures by investigators from the University of Alaska, Fairbanks, as part of a special Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) study to identify variance in total uranium contents related to natural factors such as seasonal changes, source types, and geologic/geographic environments. Histograms and statistical summaries of total uranium in a number of sample populations presented herein indicate that water samples collected in late summer have a mean uranium content that is slightly higher than the mean for waters collected in the spring. Dilution and/or evaporative concentration are possible causes for this difference. Sediment samples collected from streams and springs have a slightly higher mean uranium content than those collected from lakes, and this is consistent with HSSR data from other Alaskan areas. The Alaskan investigators will complete a detailed analysis of variance study of these data in the near future and a second open-file report will be forthcoming upon its completion

  14. Summary of Inorganic Compositional Data for Groundwater, Soil-Water, and Surface-Water Samples at the Headgate Draw Subsurface Drip Irrigation Site

    Energy Technology Data Exchange (ETDEWEB)

    Geboy, Nicholas J.; Engle, Mark A.; Schroeder, Karl T.; Zupanic, John W.

    2007-01-01

    As part of a 5-year project on the impact of subsurface drip irrigation (SDI) application of coalbed-methane (CBM) produced waters, water samples were collected from the Headgate Draw SDI site in the Powder River Basin, Wyoming, USA. This research is part of a larger study to understand short- and long-term impacts on both soil and water quality from the beneficial use of CBM waters to grow forage crops through use of SDI. This document provides a summary of the context, sampling methodology, and quality assurance and quality control documentation of samples collected prior to and over the first year of SDI operation at the site (May 2008-October 2009). This report contains an associated database containing inorganic compositional data, water-quality criteria parameters, and calculated geochemical parameters for samples of groundwater, soil water, surface water, treated CBM waters, and as-received CBM waters collected at the Headgate Draw SDI site.

  15. Daily variations of delta 18O and delta D in daily samplings of air water vapour and rain water in the Amazon Basin

    International Nuclear Information System (INIS)

    Matsui, E.; Salati, E.; Ribeiro, M.N.G.; Tancredi, A.C.F.N.S.; Reis, C.M. dos

    1984-01-01

    The movement of rain water in the soil from 0 to 120 cm depth using delta 18 O weekly variations is studied. A study of the delta D variability in water vapour and rain water samples during precipitation was also done, the samples being collected a 3 minute intervals from the beginning to the end of precipitation. (M.A.C.) [pt

  16. Application of empore TM strontium rad disks to the analysis of radiostrontium in environmental water samples

    International Nuclear Information System (INIS)

    Smith, L.L.; Seely, D.C.; Shannon, R.T.

    1996-01-01

    A solid phase extraction method for analyzing radioactive strontium in surface, ground, and drinking waters is presented. Strontium is simply isolated by pulling an acidified sample aliquot through an Empore TM strontium rad disk with a vacuum, and the disk is subsequently assayed for beta activity. The method is efficient, safe, reliable, and potentially field deployable. Sample preparation and counting source preparation may be condensed into a single procedure, thereby improving efficiency and eliminating many potential sources of laboratory error. Moreover, many of the hazardous chemicals associated with traditional strontium procedures are eliminated. Samples are easily batched, and a one-liter sample may be prepared with as little as 20 min of effort. For a one-liter aqueous sample, up to 3 mg of strontium can be retained by the disks. Chemical and radiometric interferences are discussed. (orig.)

  17. Screening and Quantification of Aliphatic Primary Alkyl Corrosion Inhibitor Amines in Water Samples by Paper Spray Mass Spectrometry.

    Science.gov (United States)

    Jjunju, Fred P M; Maher, Simon; Damon, Deidre E; Barrett, Richard M; Syed, S U; Heeren, Ron M A; Taylor, Stephen; Badu-Tawiah, Abraham K

    2016-01-19

    Direct analysis and identification of long chain aliphatic primary diamine Duomeen O (n-oleyl-1,3-diaminopropane), corrosion inhibitor in raw water samples taken from a large medium pressure water tube boiler plant water samples at low LODs (boiler plant and other related samples in the water treatment industry. This approach was applied for the analysis of three complex water samples including feedwater, condensate water, and boiler water, all collected from large medium pressure (MP) water tube boiler plants, known to be dosed with varying amounts of polyamine and amine corrosion inhibitor components. Polyamine chemistry is widely used for example in large high pressure (HP) boilers operating in municipal waste and recycling facilities to prevent corrosion of metals. The samples used in this study are from such a facility in Coventry waste treatment facility, U.K., which has 3 × 40 tonne/hour boilers operating at 17.5 bar.

  18. Comparative study of uranium concentration in water samples of SW and NE Punjab, India

    International Nuclear Information System (INIS)

    Saini, Komal; Bajwa, B.S.

    2014-01-01

    Since the commencement of the earth, radiations and natural radioactivity has always been a part of environment. Uranium is heaviest naturally occurring element which is widespread in nature, mainly occurs in granites mineral deposits. The natural weathering of rocks such as granite dissolves the natural uranium, which goes into groundwater by leaching and precipitation called illumination process. People are always exposed to certain amount of uranium from air, water, soil and food as it is usually present in these components. About 85% of ingested uranium enter into human body through drinking water which makes it very important to estimate uranium concentration in potable water. Uranium and some other heavy metals may increase the risk of kidney damage, cancer diseases where experimental evidence suggests that respiratory and reproductive system are also affected by uranium exposure. In the present study comparative study of uranium concentration in potable water samples of SW and NE Punjab has been analysed

  19. Studying the effect of over-modulation on the output voltage of three-phase single-stage grid-connected boost inverter

    Directory of Open Access Journals (Sweden)

    A. Abbas Elserougi

    2013-09-01

    Full Text Available Voltage boosting is very essential issue in renewable-energy fed applications. The classical two-stage power conversion process is typically used to interface the renewable energy sources to the grid. For better efficiency, single-stage inverters are recommended. In this paper, the performance of single-stage three-phase grid-connected boost inverter is investigated when its gain is extended by employing over-modulation technique. Using of over-modulation is compared with the employment of third order harmonic injection. The latter method can increase the inverter gain by 15% without distorting the inverter output voltage. The performance of extended gain grid-connected boost inverter is also tested during normal operation as well as in the presence of grid side disturbances. Simulation and experimental results are satisfactory.

  20. Immediate two-stage tissue expander vs single-stage direct-to-implant breast reconstruction: two case reports of identical twins with BRCA 2 mutation

    Directory of Open Access Journals (Sweden)

    Aleš Porčnik

    2015-12-01

    Full Text Available In order to achieve the best aesthetic result after immediate implant-based breast reconstruction, all the advantages and disadvantages of two-stage tissue expander and single-stage direct-to-implant breast reconstruction should be considered. Decision about the type of implant-based reconstruction is based on the consultations outcomes after multidisciplinary team meeting of breast and reconstructive specialist, but patients own wishes should be prioritised.

  1. Quantitative targeted and retrospective data analysis of relevant pesticides, antibiotics and mycotoxins in bakery products by liquid chromatography-single-stage Orbitrap mass spectrometry.

    Science.gov (United States)

    De Dominicis, Emiliano; Commissati, Italo; Gritti, Elisa; Catellani, Dante; Suman, Michele

    2015-01-01

    In addition to 'traditional' multi-residue and multi-contaminant multiple reaction monitoring (MRM) mass spectrometric techniques devoted to quantifying a list of targeted compounds, the global food industry requires non-targeted methods capable of detecting other possible potentially hazardous compounds. Ultra-high-performance liquid chromatography combined with a single-stage Orbitrap high-resolution mass spectrometer (UHPLC-HRMS Exactive™-Orbitrap Technology) was successfully exploited for the complete selective and quantitative determination of 33 target compounds within three major cross categories (pesticides, antibiotics and mycotoxins) in bakery matrices (specifically milk, wheat flour and mini-cakes). Resolution was set at 50 000 full width at half maximum (FWHM) to achieve the right compromise between an adequate scan speed and selectivity, allowing for the limitations related to the necessary generic sample preparation approach. An exact mass with tolerance of 5 ppm and minimum peak threshold of 10 000 units were fixed as the main identification conditions, including retention time and isotopic pattern as additional criteria devoted to greatly reducing the risk of false-positive findings. The full validation for all the target analytes was performed: linearity, intermediate repeatability and recovery (28 analytes within 70-120%) were positively assessed; furthermore, limits of quantification between 5 and 100 µg kg(-1) (with most of the analytes having a limit of detection below 6 µg kg(-1)) indicate good performance, which is compatible with almost all the regulatory needs. Naturally contaminated and fortified mini-cakes, prepared through combined use of industrial and pilot plant production lines, were analysed at two different concentration levels, obtaining good overall quantitative results and providing preliminary indications of the potential of full-scan HRMS cluster analysis. The effectiveness of this analytical approach was also tested in

  2. Microwave-assisted headspace single-drop microextration of chlorobenzenes from water samples

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, Lorena [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Domini, Claudia E. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Grane, Nuria [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain); Psillakis, Elefteria [Department of Environmental Engineering, Technical University of Crete, Polytechneioupolis, GR-73100 Chania, Crete (Greece); Canals, Antonio [Departamento de Quimica Analitica, Nutricion y Bromatologia, Universidad de Alicante, P.O. Box 99, E-03080 Alicante (Spain)]. E-mail: a.canals@ua.es

    2007-05-29

    A one-step and in-situ sample preparation method used for quantifying chlorobenzene compounds in water samples has been developed, coupling microwave and headspace single-drop microextraction (MW-HS-SDME). The chlorobenzenes in water samples were extracted directly onto an ionic liquid single-drop in headspace mode under the aid of microwave radiation. For optimization, a Plackett-Burman screening design was initially used, followed by a mixed-level factorial design. The factors considered were: drop volume, aqueous sample volume, stirring speed, ionic strength, extraction time, ionic liquid type, microwave power and length of the Y-shaped glass-tube. The optimum experimental conditions found from this statistical evaluation were: a 5 {mu}L microdrop of 1-hexyl-3-methylimidazolium hexafluorophosphate exposed for 20 min to the headspace of a 30 mL aqueous sample, irradiated by microwaves at 200 W and placed in a 50 mL spherical flask connected to a 25 cm Y-shaped glass-tube. Under the optimised experimental conditions, the response of a high performance liquid chromatographic system was found to be linear over the range studied and with correlation coefficients ranging between 0.9995 and 0.9999. The method showed a good level of repeatability, with relative standard deviations varying between 2.3 and 8.3% (n = 5). Detection limits were found in the low {mu}g L{sup -1} range varying between 0.016 and 0.039 {mu}g L{sup -1}. Overall, the performance of the proposed method demonstrated the favourable effect of microwave sample irradiation upon HS-SDME. Finally, recovery studies from different types of environmental water samples revealed that matrix had little effect upon extraction.

  3. Microwave-assisted headspace single-drop microextration of chlorobenzenes from water samples

    International Nuclear Information System (INIS)

    Vidal, Lorena; Domini, Claudia E.; Grane, Nuria; Psillakis, Elefteria; Canals, Antonio

    2007-01-01

    A one-step and in-situ sample preparation method used for quantifying chlorobenzene compounds in water samples has been developed, coupling microwave and headspace single-drop microextraction (MW-HS-SDME). The chlorobenzenes in water samples were extracted directly onto an ionic liquid single-drop in headspace mode under the aid of microwave radiation. For optimization, a Plackett-Burman screening design was initially used, followed by a mixed-level factorial design. The factors considered were: drop volume, aqueous sample volume, stirring speed, ionic strength, extraction time, ionic liquid type, microwave power and length of the Y-shaped glass-tube. The optimum experimental conditions found from this statistical evaluation were: a 5 μL microdrop of 1-hexyl-3-methylimidazolium hexafluorophosphate exposed for 20 min to the headspace of a 30 mL aqueous sample, irradiated by microwaves at 200 W and placed in a 50 mL spherical flask connected to a 25 cm Y-shaped glass-tube. Under the optimised experimental conditions, the response of a high performance liquid chromatographic system was found to be linear over the range studied and with correlation coefficients ranging between 0.9995 and 0.9999. The method showed a good level of repeatability, with relative standard deviations varying between 2.3 and 8.3% (n = 5). Detection limits were found in the low μg L -1 range varying between 0.016 and 0.039 μg L -1 . Overall, the performance of the proposed method demonstrated the favourable effect of microwave sample irradiation upon HS-SDME. Finally, recovery studies from different types of environmental water samples revealed that matrix had little effect upon extraction

  4. Chemical and Microbiological Analysis of Certain Water Sources and Industrial Wastewater Samples in Dakahlia Governorate

    International Nuclear Information System (INIS)

    El-Fadaly, H.; El-Defrawy, M.M.; El-Zawawy, F.; Makia, D.

    1999-01-01

    The chemical analysis included quantitative measurement of electrical conductivity, alkalinity , hardness sulphate, ph, total dissolved solids, chloride, as well as dissolved oxygen was carried out. The microbiological examination for different water sources and industrial wastewater samples was also conducted. some of heavy metals, Co 2+ Cu 2+ Fe 3+ and Mn 2+ were determined in fresh water, while other metals, such as Cr 6+ , Co 2+ , Zn 2+ and Ni 2+ were measured in industrial wastewater. Results of the chemical analysis showed that all measured parameters were found within the limitation either national or international law, except some samples which showed higher values than the permissible limits for some measured parameters. The microbiological analysis exhibited presence of yeasts, fungi and bacteria. Most bacterial isolates were short rod, spore formers as well as coccoid shaped bacteria. The efficiency of water treatment process on the reduction of microbial load was also calculated. Regarding the pathogenic bacteria, data showed that neither water samples nor industrial wastewater contain pathogens when using specific cultivation media for the examination. Furthermore, data proved the possibility of recycling of the tested industrial wastewater on which some microorganisms can grow. Data showed that the percent of heavy metals removal can reach to more than 70% in some cases as a result to bacterial treatment of industrial wastewater

  5. Spectrophotometric determination of mercury in water samples after preconcentration using dispersive liquid-liquid microextraction.

    Science.gov (United States)

    Lemos, Valfredo Azevedo; dos Santos, Liz Oliveira; Silva, Eldevan dos Santos; Vieira, Emanuel Vitor dos Santos

    2012-01-01

    A simple method for the determination of mercury in water samples after preconcentration using dispersive liquid-liquid microextraction is described. The procedure is based on the extraction of mercury in the form of a complex and its subsequent determination by spectrophotometry. The complex is formed between Hg(II) and 2-(2-benzothiazolylazo)-p-cresol. The detection at 650 nm is performed directly in the metal-rich phase, which is spread on a triacetylcellulose membrane. The method eliminates the need to use a cuvet or large quantities of samples and reagents. The parameters that influence the preconcentration were studied, and the analytical characteristics were determined. The enrichment factor and the consumptive index for this method were 64 and 0.16 mL, respectively. The LOD (3.3 microg/L) and LOQ (11.1 microg/L) were also determined. The accuracy of the method was tested by the determination of mercury in certified reference materials BCR 397 (Human Hair) and SRM 2781 (Domestic Sludge). The method was applied to the determination of mercury in samples of drinking water, sea water, and river water.

  6. Microfluidic chip with optical sensor for rapid detection of nerve agent Sarin in water samples

    Science.gov (United States)

    Tan, Hsih Yin; Nguyen, Nam-Trung; Loke, Weng Keong; Tan, Yong Teng

    2007-12-01

    The chemical warfare agent Sarin is an organophosphate that is highly toxic to humans as they can act as cholinesterase inhibitors, that disrupts neuromuscular transmission. As these nerve agents are colorless, odorless and highly toxic, they can be introduced into drinking water as a means of terrorist sabotage. Hence, numerous innovative devices and methods have been developed for rapid detection of these organophosphates. Microfluidic technology allows the implementation of fast and sensitive detection of Sarin. In this paper, a micro-total analysis systems (TAS), also known as Lab-on-a-chip, fitted with an optical detection system has been developed to analyze the presence of the nerve agent sarin in water samples. In the present set-up, inhibition of co-introduced cholinesterase and water samples containing trace amounts of nerve agent sarin into the microfluidic device was used as the basis for selective detection of sarin. The device was fabricated using polymeric micromachining with PMMA (poly (methymethacrylate)) as the substrate material. A chromophore was utilized to measure the activity of remnant cholinesterase activity, which is inversely related to the amount of sarin present in the water samples. Comparisons were made between two different optical detection techniques and the findings will be presented in this paper. The presented measurement method is simple, fast and as sensitive as Gas Chromatography.

  7. Sampling problems and the determination of mercury in surface water, seawater, and air

    International Nuclear Information System (INIS)

    Das, H.A.; van der Sloot, H.A.

    1976-01-01

    Analysis of surface water for mercury comprises the determination of both ionic and organically bound mercury in solution and that of the total mercury content of the suspended matter. Eventually, metallic mercury has to be determined too. Requirements for the sampling procedure are given. A method for the routine determination of mercury in surface water and seawater was developed and applied to Dutch surface waters. The total sample volume is 2500 ml. About 500 ml is used for the determination of the content of suspended matter and the total amount of mercury in the water. The sample is filtered through a bed of previously purified active charcoal at a low flow-rate. The main portion ca. 2000 ml) passes a flow-through centrifuge to separate the solid fraction. One liter is used to separate ''inorganic'' mercury by reduction, volatilization in an airstream and adsorption on active charcoal. The other liter is led through a column of active charcoal to collect all mercury. The procedures were checked with 197 Hg radiotracer both as an ion and incorporated in organic compounds. The mercury is determined by thermal neutron activation, followed by volatilization in a tube furnace and adsorption on a fresh carbon bed. The limit of determination is approximately equal to 1 ng 1 -1 . The rate of desorption from and adsorption on suspended material has been measured as a function of a pH of the solution for Hg +2 and various other ions. It can be concluded that only the procedure mentioned above does not disturb the equilibrium. The separation of mercury from air is obtained by suction of 1 m 3 through a 0.22 μm filter and a charcoal bed. The determination is then performed as in the case of the water samples

  8. Lead in drinking water: sampling in primary schools and preschools in south central Kansas.

    Science.gov (United States)

    Massey, Anne R; Steele, Janet E

    2012-03-01

    Studies in Philadelphia, New York City, Houston, Washington, DC, and Greenville, North Carolina, have revealed high lead levels in drinking water. Unlike urban areas, lead levels in drinking water in suburban and rural areas have not been adequately studied. In the study described in this article, drinking water in primary schools and preschools in five suburban and rural south central Kansas towns was sampled to determine if any exceeded the U.S. Environmental Protection Agency (U.S. EPA) guidance level for schools and child care facilities of 20 parts per billion (ppb). The results showed a total of 32.1% of the samples had detectable lead levels and 3.6% exceeded the U.S. EPA guidance level for schools and child care providers of 20 ppb. These results indicate that about one-third of the drinking water consumed by children age six and under in the five suburban and rural south central Kansas towns studied has some lead contamination, exposing these children to both short-term and long-term health risks. The authors suggest a need for increased surveillance of children's drinking water in these facilities.

  9. Single-stage endoscopic treatment for mild to moderate acute cholangitis associated with choledocholithiasis: a multicenter, non-randomized, open-label and exploratory clinical trial.

    Science.gov (United States)

    Eto, Kazunori; Kawakami, Hiroshi; Haba, Shin; Yamato, Hiroaki; Okuda, Toshinori; Yane, Kei; Hayashi, Tsuyoshi; Ehira, Nobuyuki; Onodera, Manabu; Matsumoto, Ryusuke; Matsubara, Yu; Takagi, Tomofumi; Sakamoto, Naoya

    2015-12-01

    Two-stage treatment involving stone removal after drainage is recommended for mild to moderate acute cholangitis associated with choledocholithiasis. However, single-stage treatment has some advantages. We aimed to assess the efficacy and safety of single-stage endoscopic treatment for mild to moderate acute cholangitis associated with choledocholithiasis. A multicenter, non-randomized, open-label, exploratory clinical trial was performed in 12 institutions. A total of 50 patients with a naïve papilla and a body temperature ≥37 °C who were diagnosed with mild to moderate cholangitis associated with choledocholithiasis were enrolled between August 2012 and February 2014. Of the 50 patients, 15 had mild cholangitis and 35 had moderate cholangitis. The median number of common bile duct stones was 2 (range, 1-8), and the median diameter of the common bile duct stones was 7.5 mm (range, 1-18). The cure rate of acute cholangitis within 4 days after single-stage treatment was 90% (45/50) based on a body temperature choledocholithiasis (clinical trial registration number: UMIN000008494). © 2015 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  10. Single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation in surgical treatment for single-segment lumbar spinal tuberculosis.

    Science.gov (United States)

    Zeng, Hao; Wang, Xiyang; Zhang, Penghui; Peng, Wei; Liu, Zheng; Zhang, Yupeng

    2015-01-01

    The aim of this study is to determine the feasibility and efficacy of surgical management of single-segment lumbar spinal tuberculosis (TB) by using single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation. Seventeen cases of single-segment lumbar TB were treated with single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation. The mean follow-up was 36.9 months (range: 24-62 months). The kyphotic angle ranged from 15.2-35.1° preoperatively, with an average measurement of 27.8°. The American Spinal Injury Association (ASIA) score system was used to evaluate the neurological deficits and erythrocyte sedimentation rate (ESR) used to judge the activity of TB. Spinal TB was completely cured in all 17 patients. There was no recurrent TB infection. The postoperative kyphotic angle was 6.6-10.2°, 8.1° in average, and there was no significant loss of the correction at final follow-up. Solid fusion was achieved in all cases. Neurological condition in all patients was improved after surgery. Single-stage posterior transforaminal lumbar interbody fusion, debridement, limited decompression, 3-column reconstruction, and posterior instrumentation can be a feasible and effective method the in treatment of single-segment lumbar spinal TB.

  11. Application of environmental sampling to flexible endoscope reprocessing: the importance of monitoring the rinse water.

    Science.gov (United States)

    Muscarella, Lawrence F

    2002-05-01

    The routine sampling of environmental surfaces within a healthcare facility is generally not recommended by the Centers for Disease Control and Prevention (CDC), the Association for the Advancement of Medical Instrumentation (AAMI), and several other healthcare organizations. There are a few circumstances, however, for which some organizations do recommend this practice. For instance, the CDC and the Association for Professionals in Infection Control and Epidemiology (APIC) recommend environmental sampling as clinically required during an outbreak investigation. The CDC and AAMI also recommend routine sampling of the rinse water used during hemodialyzer (but not endoscope) reprocessing. The rationale for this recommendation is based in part on reports of pyrogenic responses, patient infections, and bacteremia due to waterborne, gram-negative bacteria during hemodialysis. To determine whether the basis for this rationale might similarly apply to the rinse water used during endoscope reprocessing, the Food and Drug Administration's medical device reporting database, the endoscope reprocessing literature, and other sources were reviewed. The results of this review indicate that nosocomial outbreaks linked to endoscopes contaminated with gram-negative bacteria have been frequently reported. As a result, for several reasons, including to minimize the risk of patient infection due to gram-negative bacteria following endoscopy, this article recommends routine microbiologic sampling of the rinse water used during endoscope reprocessing.

  12. Stable isotope characterization of pan-derived and directly sampled atmospheric water vapour

    International Nuclear Information System (INIS)

    Maric, R.; St. Amour, N.A.; Gibson, J.J.; Edwards, T.W.D.

    2002-01-01

    Isotopic characterization of atmospheric water vapour, δ A , and its temporal variability are important prerequisites for quantifying water balance of surface reservoirs and partitioning of evaporation and transpiration fluxes using isotope techniques. Here we present results from a detailed comparison of several methods for determining δ A in field situations, (i) by back-calculation from isotopic and micrometeorological monitoring of a steady-state terminal reservoir (standard Class-A evaporation pan) using boundary-layer mass transfer models [1], (ii) through direct (cryogenic) sampling of ambient atmospheric moisture, and (iii) using the precipitation-equilibrium approximation (i.e., δ A =δ P - ε*)

  13. Ground water chemistry in SFR. Results from a sampling and analysis campaign year 2000

    International Nuclear Information System (INIS)

    Nilsson, Ann-Chatrin

    2002-02-01

    The ground water chemistry is regularly controlled at four observation points/boreholes within the control program for the operational stage in SFR. Initially, samples were taken twice a year, but after a revision of the control program in 1996, it was limited to yearly sampling with a more comprehensive sampling from several boreholes every fifth year. Such a comprehensive program was performed in year 2000. In three boreholes tests were made using a mobile field laboratory for 'on-line' analysis of pH-value, redox potential, conductivity, free oxygen and temperature. Gas analysis and determination of microbes were also made. In the other boreholes with sufficient flow, manual samples were taken. In this report the new results are presented together with a complete compilation of chemistry data since the start of the control program in 1989

  14. Volatile organic compound matrix spike recoveries for ground- and surface-water samples, 1997-2001

    Science.gov (United States)

    Rowe, Barbara L.; Delzer, Gregory C.; Bender, David A.; Zogorski, John S.

    2005-01-01

    The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program used field matrix spikes (FMSs), field matrix spike replicates (FMSRs), laboratory matrix spikes (LMSs), and laboratory reagent spikes (LRSs), in part, to assess the quality of volatile organic compound (VOC) data from water samples collected and analyzed in more than 50 of the Nation's largest river basins and aquifers (Study Units). The data-quality objectives of the NAWQA Program include estimating the extent to which variability, degradation, and matrix effects, if any, may affect the interpretation of chemical analyses of ground- and surface-water samples. In order to help meet these objectives, a known mass of VOCs was added (spiked) to water samples collected in 25 Study Units. Data within this report include recoveries from 276 ground- and surface-water samples spiked with a 25-microliter syringe with a spike solution containing 85 VOCs to achieve a concentration of 0.5 microgram per liter. Combined recoveries for 85 VOCs from spiked ground- and surface-water samples and reagent water were used to broadly characterize the overall recovery of VOCs. Median recoveries for 149 FMSs, 107 FMSRs, 20 LMSs, and 152 LRSs were 79.9, 83.3, 113.1, and 103.5 percent, respectively. Spike recoveries for 85 VOCs also were calculated individually. With the exception of a few VOCs, the median percent recoveries determined from each spike type for individual VOCs followed the same pattern as for all VOC recoveries combined, that is, listed from least to greatest recovery-FMSs, FMSRs, LRSs, and LMSs. The median recoveries for individual VOCs ranged from 63.7 percent to 101.5 percent in FMSs; 63.1 percent to 101.4 percent in FMSRs; 101.7 percent to 135.0 percent in LMSs; and 91.0 percent to 118.7 percent in LRSs. Additionally, individual VOC recoveries were compared among paired spike types, and these recoveries were used to evaluate potential bias in the method. Variability associated with field

  15. Efficient sample preparation method based on solvent-assisted dispersive solid-phase extraction for the trace detection of butachlor in urine and waste water samples.

    Science.gov (United States)

    Aladaghlo, Zolfaghar; Fakhari, Alireza; Behbahani, Mohammad

    2016-10-01

    In this work, an efficient sample preparation method termed solvent-assisted dispersive solid-phase extraction was applied. The used sample preparation method was based on the dispersion of the sorbent (benzophenone) into the aqueous sample to maximize the interaction surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by inserting a solution of the sorbent and disperser solvent into the aqueous sample. The cloudy solution created from the dispersion of the sorbent in the bulk aqueous sample. After pre-concentration of the butachlor, the cloudy solution was centrifuged and butachlor in the sediment phase dissolved in ethanol and determined by gas chromatography with flame ionization detection. Under the optimized conditions (solution pH = 7.0, sorbent: benzophenone, 2%, disperser solvent: ethanol, 500 μL, centrifuged at 4000 rpm for 3 min), the method detection limit for butachlor was 2, 3 and 3 μg/L for distilled water, waste water, and urine sample, respectively. Furthermore, the preconcentration factor was 198.8, 175.0, and 174.2 in distilled water, waste water, and urine sample, respectively. Solvent-assisted dispersive solid-phase extraction was successfully used for the trace monitoring of butachlor in urine and waste water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Detection of Cryptosporidium oocysts and Giardia cysts in water samples with a Becton Dickinson FACSort flow cytometer

    NARCIS (Netherlands)

    Schets FM; Medema GJ; Boschman GD; LWL; Becton Dickinson Europe, Aalst, Belgie

    1995-01-01

    Current detection techniques for Cryptosporidium oocysts and Giardia cysts in water samples combine filtration of large volumes of water, concentration by centrifugation and flotation and immunofluorescense microscopy. The techniques are extremely labour-intensive and inefficient. The various steps

  17. Sample preparation of waste water to determine metallic contaminants by X-ray fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Gonzalez Olivos, Javier.

    1987-01-01

    Trace X-ray fluorescence spectroscopy analysis in liquid samples is preceded by sample preparation, which usually consists in the precipitation of the metallic ions and concentration over a thin cellulose filter. The samples preparation of waste water by this method is not efficient, due to the great amount of organic and insoluble matter that they contain. The purpose of this work was to determine the optimal value of pH in order to adsorbe all the insoluble matter contained in a waste water sample in the activated charcoal, so that the metallic ions could be precipitated and concentrated on a thin filter and determinated by X-ray fluorescence spectroscopy. A survey about the adsorption of some ions in activated charcoal in function of the pH was made for the following: Cr 3+ , Fe 3+ , Ni 2+ , Cu 2+ , Zn 2+ , Se 2+ , Hg 2+ , and Pb 2+ . It was observed that at pH 0, the ions are not adsorbed, but Cu 2+ and Zn 2+ are adsorbed in small amount; at pH 14, the ions are adsorbed, excluding Se, which is not adsorbed at any value of pH. If a waste water sample is treated at pH 0 with activated charcoal to adsorbe the organic and insoluble matter, most of the metallic ions are not adsorbed by the activated charcoal and could be precipitated with APDC (ammonium 1-pirrolidine dithio carbamate salt) and concentrated on a thin filter. The analysis of the metallic ions contained on the filter and those adsorbed in the activated charcoal by X-ray fluorescence spectroscopy, gave the total amount of the ions in the sample. (author)

  18. Multi-stage versus single-stage inflation and deflation cycle for alternating low pressure air mattresses to prevent pressure ulcers in hospitalised patients: a randomised-controlled clinical trial.

    Science.gov (United States)

    Demarré, L; Beeckman, D; Vanderwee, K; Defloor, T; Grypdonck, M; Verhaeghe, S

    2012-04-01

    The duration and the amount of pressure and shear must be reduced in order to minimize the risk of pressure ulcer development. Alternating low pressure air mattresses with multi-stage inflation and deflation cycle of the air cells have been developed to relieve pressure by sequentially inflating and deflating the air cells. Evidence about the effectiveness of this type of mattress in clinical practice is lacking. This study aimed to compare the effectiveness of an alternating low pressure air mattress that has a standard single-stage inflation and deflation cycle of the air cells with an alternating low pressure air mattress with multi-stage inflation and deflation cycle of the air cells. A randomised controlled trial was performed in a convenience sample of 25 wards in five hospitals in Belgium. In total, 610 patients were included and randomly assigned to the experimental group (n=298) or the control group (n=312). In the experimental group, patients were allocated to an alternating low pressure air mattress with multi-stage inflation and deflation cycle of the air cells. In the control group, patients were allocated to an alternating low pressure air mattress with a standard single-stage inflation and deflation cycle of the air cells. The outcome was defined as cumulative pressure ulcer incidence (Grade II-IV). An intention-to-treat analysis was performed. There was no significant difference in cumulative pressure ulcer incidence (Grade II-IV) between both groups (Exp.=5.7%, Contr.=5.8%, p=0.97). When patients developed a pressure ulcer, the median time was 5.0 days in the experimental group (IQR=3.0-8.5) and 8.0 days in the control group (IQR=3.0-8.5) (Mann-Whitney U-test=113, p=0.182). The probability to remain pressure ulcer free during the observation period in this trial did not differ significantly between the experimental group and the control group (log-rank χ(2)=0.013, df=1, p=0.911). An alternating low pressure air mattress with multi-stage inflation

  19. Analysis of Heavy Metals in Water and Fish (Tilapia sp.) Samples from Tasik Mutiara, Puchong

    International Nuclear Information System (INIS)

    Ismaniza Ismail; Idaliza Mat Saleh

    2012-01-01

    The concentrations of seven heavy metals (Al, As, Cd, Cu, Fe, Pb and Zn) were detected in muscle tissues of Tilapia sp. (black tilapia) collected from the lake of Taman Mutiara, Puchong. Samples were collected for several months in the end of 2009 at three sampling points. Heavy metals in fish and water samples were analyzed by Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES). Only Al, Cu, Fe and Zn were detected in the order Fe > Zn > Al > Cu, whereas concentrations of As, Cd and Pb were below the detection limit. The concentrations of heavy metals in water samples were low and below the detection limit. The levels of heavy metals in the fish samples can be considered as a serious matter of concern as it may be consumed and it signifies the degradation of lake quality. Generally, the sources of heavy metals in the Tasik Mutiara, Puchong could be attributed to the illegal waste dumping activity and discharge from the nearby sewage treatment plant into the lake which promote eutrophication in the lake. It could also be attributed to the Low Dissolved Oxygen (DO) levels in the lake. (author)

  20. TRITIUM UNCERTAINTY ANALYSIS FOR SURFACE WATER SAMPLES AT THE SAVANNAH RIVER SITE

    Energy Technology Data Exchange (ETDEWEB)

    Atkinson, R.

    2012-07-31

    Radiochemical analyses of surface water samples, in the framework of Environmental Monitoring, have associated uncertainties for the radioisotopic results reported. These uncertainty analyses pertain to the tritium results from surface water samples collected at five locations on the Savannah River near the U.S. Department of Energy's Savannah River Site (SRS). Uncertainties can result from the field-sampling routine, can be incurred during transport due to the physical properties of the sample, from equipment limitations, and from the measurement instrumentation used. The uncertainty reported by the SRS in their Annual Site Environmental Report currently considers only the counting uncertainty in the measurements, which is the standard reporting protocol for radioanalytical chemistry results. The focus of this work is to provide an overview of all uncertainty components associated with SRS tritium measurements, estimate the total uncertainty according to ISO 17025, and to propose additional experiments to verify some of the estimated uncertainties. The main uncertainty components discovered and investigated in this paper are tritium absorption or desorption in the sample container, HTO/H{sub 2}O isotopic effect during distillation, pipette volume, and tritium standard uncertainty. The goal is to quantify these uncertainties and to establish a combined uncertainty in order to increase the scientific depth of the SRS Annual Site Environmental Report.

  1. UMTRA ground water sampling techniques: Comparison of the traditional and low flow methods

    International Nuclear Information System (INIS)

    1995-07-01

    This report describes the potential changes in water quality data that may occur with the conversion from MBV (multiple bore volume) to LF (low flow) sampling and provides two examples of how such a change might impact Project decisions. The existing scientific literature on LF sampling is reviewed and the new LF data from three UMTRA Uranium Mill Tailings Remedial Action Project sites are evaluated seeking answers to the questions posed above. Several possible approaches, that the UMTRA Project may take to address issues unanswered by the literature are presented and compared, and a recommendation is offered for the future direction of the LF conversion effort

  2. First Total Reflection X-Ray Fluorescence round-robin test of water samples: Preliminary results

    Science.gov (United States)

    Borgese, Laura; Bilo, Fabjola; Tsuji, Kouichi; Fernández-Ruiz, Ramón; Margui, Eva; Streli, Christina; Pepponi, Giancarlo; Stosnach, Hagen; Yamada, Takashi; Vandenabeele, Peter; Maina, David M.; Gatari, Michael; Shepherd, Keith D.; Towett, Erick K.; Bennun, Leonardo; Custo, Graciela; Vasquez, Cristina; Depero, Laura E.

    2014-11-01

    Total Reflection X-Ray Fluorescence (TXRF) is a mature technique to evaluate quantitatively the elemental composition of liquid samples deposited on clean and well polished reflectors. In this paper the results of the first worldwide TXRF round-robin test of water samples, involving 18 laboratories in 10 countries are presented and discussed. The test was performed within the framework of the VAMAS project, interlaboratory comparison of TXRF spectroscopy for environmental analysis, whose aim is to develop guidelines and a standard methodology for biological and environmental analysis by means of the TXRF analytical technique.

  3. Iodide-assisted total lead measurement and determination of different lead fractions in drinking water samples.

    Science.gov (United States)

    Zhang, Yuanyuan; Ng, Ding-Quan; Lin, Yi-Pin

    2012-07-01

    Lead and its compounds are toxic and can harm human health, especially the intelligence development in children. Accurate measurement of total lead present in drinking water is crucial in determining the extent of lead contamination and human exposure due to drinking water consumption. The USEPA method for total lead measurement (no. 200.8) is often used to analyze lead levels in drinking water. However, in the presence of high concentration of the tetravalent lead corrosion product PbO(2), the USEPA method was not able to fully recover particulate lead due to incomplete dissolution of PbO(2) particles during strong acid digestion. In this study, a new procedure that integrates membrane separation, iodometric PbO(2) measurement, strong acid digestion and ICP-MS measurement was proposed and evaluated for accurate total lead measurement and quantification of different lead fractions including soluble Pb(2+), particulate Pb(II) carbonate and PbO(2) in drinking water samples. The proposed procedure was evaluated using drinking water reconstituted with spiked Pb(2+), spiked particulate Pb(II) carbonate and in situ formed or spiked PbO(2). Recovery tests showed that the proposed procedure and the USEPA method can achieve 93-112% and 86-103% recoveries respectively for samples containing low PbO(2) concentrations (0.018-0.076 mg Pb per L). For samples containing higher concentrations of PbO(2) (0.089-1.316 mg Pb per L), the USEPA method failed to meet the recovery requirement for total lead (85-115%) while the proposed method can achieve satisfactory recoveries (91-111%) and differentiate the soluble Pb(2+), particulate Pb(II) carbonate and PbO(2).

  4. Evaluation of the Goulden Large-Sample Extractor for acidic compounds in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Headley, J.V.; Dickson, L.C. [Environment Canada, Saskatoon, Saskatchewan (Canada). National Hydrology Research Inst.; Swyngedouw, C. [Chemex Labs Alberta Ltd., Calgary, Alberta (Canada); Crosley, B. [Environment Canada, Calgary, Alberta (Canada); Whitley, G. [Indian and Northern Affairs Canada, Whitehorse, Yukon Territory (Canada). Water Resources Div.

    1996-11-01

    The Goulden Large-Sample Extractor has received extensive use for monitoring and surveillance surveys of natural waters impacted by pulp and paper mills and agricultural runoff water. However, there are concerns about whether this sampler, which was originally developed for extractions of hydrophobic polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and other organochlorines, is suitable for sampling polar acidic compounds. The sampler was evaluated for recovery of surrogates for resin acids, fatty acids, herbicide acids, and chlorophenols from natural waters. Performance tests conducted in this work indicated that three surrogate compounds with K{sub p} (C{sub DCM}/C{sub water pH 2}) values from 16,700 to 1,260 were extracted from pH 2-adjusted 20-L water samples with an average recovery of 83.6%. The surrogate compounds with K{sub p} values less than 1,000 were extracted with significantly lower recoveries. The variability ranged from 10 to 36% relative standard deviation. Specific performance criteria (percent recoveries {+-} standard deviation, number of determinations in parentheses) observed for the surrogates 2,4,6-tribromophenol, heptadecanoic acid, O-methylpodocarpic acid, dichlorophenylacetic acid, and 4-bromophenol were 89.5 {+-} 24.0 (17), 82.8 {+-} 21.7 (18), 78.4 {+-} 14.8 (18), 41.9 {+-} 8.5 (16), and 22.1 {+-} 8.1 (19), respectively. Low recoveries of the 4-bromophenol surrogate may be due in part to side reactions with diazomethane. As a result, 4-bromophenol is not recommended as a surrogate. These values can be used to provide guidelines for acceptable surrogate recoveries and validation of extractions of polar acidic compounds.

  5. Temephos Removal From Water Samples by Silver Modified Zero-Valent Iron Nanoparticles

    Directory of Open Access Journals (Sweden)

    Shiralipour

    2015-01-01

    Full Text Available Background Temephos is an organophosphate pesticide used as larvicide in the environment. Although not extremely hazardous, it can be risky for human health in the moderate concentrations. Objectives This study investigated the quantitative removal efficiency of temephos, an organophosphate pesticide, from contaminated water by silver-modified ZVINPs. In addition, the operational parameters affected on removal process were optimized. Materials and Methods In the current study, three water samples from different parts of Iran such as Ahvaz tap water, the Karoon River passing through Khoramshahr city, and the Caspian Sea were collected. A new method for effective removal of temephos from the sample solutions by silver modified zero-valent iron nanoparticles as an efficient adsorbent was introduced. Results For a typical solution in which temephos was removed about 21% by iron zero-valent nanoparticles, modification by silver improved removal method was up to about 99%. The required time for the complete removal of temephos was about eight minutes. Variation of pH and concentration of KNO3 as an electrolyte was considerably ineffective on the efficient temephos removal. Adsorption studies of the method were followed by Langmuir isotherm. Maximum temephos adsorption amount was 12.65 mg/g under optimal conditions. The proposed method was simple, fast and safe to treat temephos polluted waters. Preparation of the adsorbent was easy and removal time was short. Conclusions Briefly, the current study represents a novel method to eliminate temephos as an organophosphate compound from water samples with modified zero-valent iron nanoparticles.

  6. Derivative activation analysis of phosphorus at ppb levels in water samples

    International Nuclear Information System (INIS)

    Arunachalam, J.; John, A.; Gangadharan, S.

    1991-01-01

    A neutron activation analysis procedure has been developed for the indirect determination of phosphorus as orthophosphate at ppb levels, via the formation of antimonyl phosphomolybdic acid. The complex is adsorbed on Sephadex G-25 resin and the antimony is estimated through NAA, allowing the determination of phosphorus. The procedure provides an easy method to adopt for the routine determination of phosphorus at ≥ 10 ng ml -1 levels with good precision, in water samples. (author) 6 refs.; 5 tabs

  7. Real-Time PCR for Quantification of Giardia and Cryptosporidium in Environmental Water Samples and Sewage

    OpenAIRE

    Guy, Rebecca A.; Payment, Pierre; Krull, Ulrich J.; Horgen, Paul A.

    2003-01-01

    The protozoan pathogens Giardia lamblia and Cryptosporidium parvum are major causes of waterborne enteric disease throughout the world. Improved detection methods that are very sensitive and rapid are urgently needed. This is especially the case for analysis of environmental water samples in which the densities of Giardia and Cryptosporidium are very low. Primers and TaqMan probes based on the β-giardin gene of G. lamblia and the COWP gene of C. parvum were developed and used to detect DNA co...

  8. Microbial Safety of Low Water Activity Foods: Study of Simulated and Durban Household Samples

    OpenAIRE

    Ijabadeniyi, O. A.; Pillay, Y.

    2017-01-01

    Sixty household low water activity foods were examined and a simulative study was conducted in a high sugar, low aw almond and macadamia butter to determine the survival of Bacillus cereus and Staphylococcus aureus ATCC 25923. Results obtained from 60 low aw samples collected at household level had some significant differences (P≤0,05) within food categories amongst the various tests. Spices had the highest number of aerobic bacteria, aerobic spore-formers, anaerobic spore-formers, and S. aur...

  9. Molecular Characterization of Cryptosporidium Oocysts in Samples of Raw Surface Water and Wastewater

    OpenAIRE

    Xiao, Lihua; Singh, Ajaib; Limor, Josef; Graczyk, Thaddeus K.; Gradus, Steve; Lal, Altaf

    2001-01-01

    Recent molecular characterizations of Cryptosporidium parasites make it possible to differentiate the human-pathogenic Cryptosporidium parasites from those that do not infect humans and to track the source of Cryptosporidium oocyst contamination in the environment. In this study, we used a small-subunit rRNA-based PCR-restriction fragment length polymorphism (RFLP) technique to detect and characterize Cryptosporidium oocysts in 55 samples of raw surface water collected from several areas in t...

  10. Molecular method for detection of total coliforms in drinking water samples.

    Science.gov (United States)

    Maheux, Andrée F; Boudreau, Dominique K; Bisson, Marc-Antoine; Dion-Dupont, Vanessa; Bouchard, Sébastien; Nkuranga, Martine; Bergeron, Michel G; Rodriguez, Manuel J

    2014-07-01

    This work demonstrates the ability of a bacterial concentration and recovery procedure combined with three different PCR assays targeting the lacZ, wecG, and 16S rRNA genes, respectively, to detect the presence of total coliforms in 100-ml samples of potable water (presence/absence test). PCR assays were first compared to the culture-based Colilert and MI agar methods to determine their ability to detect 147 coliform strains representing 76 species of Enterobacteriaceae encountered in fecal and environmental settings. Results showed that 86 (58.5%) and 109 (74.1%) strains yielded a positive signal with Colilert and MI agar methods, respectively, whereas the lacZ, wecG, and 16S rRNA PCR assays detected 133 (90.5%), 111 (75.5%), and 146 (99.3%) of the 147 total coliform strains tested. These assays were then assessed by testing 122 well water samples collected in the Québec City region of Canada. Results showed that 97 (79.5%) of the samples tested by culture-based methods and 95 (77.9%), 82 (67.2%), and 98 (80.3%) of samples tested using PCR-based methods contained total coliforms, respectively. Consequently, despite the high genetic variability of the total coliform group, this study demonstrated that it is possible to use molecular assays to detect total coliforms in potable water: the 16S rRNA molecular assay was shown to be as efficient as recommended culture-based methods. This assay might be used in combination with an Escherichia coli molecular assay to assess drinking water quality. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  11. UMTRA project water sampling and analysis plan, Old and New Rifle, Colorado

    International Nuclear Information System (INIS)

    1994-07-01

    Surface remedial action at the Rifle, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project site began in the spring of 1992. Results of water sampling at the Old and New Rifle processing sites for recent years indicate that ground water contamination occurs in the shallow unconfined alluvial aquifer (the uppermost aquifer) and less extensively in the underlying Wasatch Formation. Uranium and sulfate continue to exceed background ground water concentrations and/or maximum concentration limits at and downgradient from the former processing sites. These constituents provide the best indication of changes in contaminant distribution. Contamination in the uppermost (alluvial) aquifer at New Rifle extends a minimum of approximately 5000 feet (ft) (1,524 meters [m]) downgradient. At Old Rifle, the extent of contamination in the alluvial aquifer is much less (a minimum of approximately 1,000 ft [305 m]), partially due to differences in hydrologic regime. For example, the Old Rifle site lies in a relatively narrow alluvial floodplain; the New Rifle site lies in a broad floodplain. Data gathering for the Rifle baseline risk assessment is under way. The purpose of this effort is to determine with greater precision the background ground water quality and extent of ground water contamination at the processing sites. Historical surface water quality indicates that the Colorado River has not been affected by uranium processing activities. No compliance monitoring of the Estes Gulch disposal cell has been proposed, because ground water in the underlying Wasatch Formation is limited use (Class 111) ground water and because the disposal cell is hydrogeologically isolated from the uppermost aquifer

  12. Quantification and identification of aerobic bacteria in holy water samples from a German environment.

    Science.gov (United States)

    König, Christoph; Tauchnitz, Stephanie; Kunzelmann, Heike; Horn, Christian; Blessing, Frithjof; Kohl, Matthias; Egert, Markus

    2017-10-01

    Despite its frequent use in many religious institutions, the microbiological quality of holy water is clearly underinvestigated. We analyzed the microbial load of 54 holy water samples, repeatedly taken in five Roman Catholic churches in the greater area of Villingen-Schwenningen, Germany, by means of aerobic colony counting and Matrix-Assisted Laser Desorption/Ionization (MALDI) Biotyping of representative isolates. Over all samples, colony counting indicated an average aerobic microbial load of 5.85 ± 3.98 × 10 3 colony forming units (CFU) ml -1 (average ± standard error of the mean (SEM)). Urban churches showed significantly higher contaminations than rural churches, probably owing to a greater number of visitors. Out of 145 bacterial isolates, 63 (43%) were identified to genus level and 39 (27%) to species level. The majority of the identified bacteria were typical human skin commensals, mainly affiliated with the genus Staphylococcus. Ten out of 20 (50%) of the identified species were classified as potential pathogens. Appropriate hygiene measures should be taken to control microbial contamination of holy water, e.g., regular water exchange, particularly in highly frequented churches.

  13. Using SPE-LC-ESI-MS/MS Analysis to Assess Disperse Dyes in Environmental Water Samples.

    Science.gov (United States)

    Zocolo, Guilherme Julião; Pilon dos Santos, Glauco; Vendemiatti, Josiane; Vacchi, Francine Inforçato; Umbuzeiro, Gisela de Aragão; Zanoni, Maria Valnice Boldrin

    2015-09-01

    We have optimized an SPE-LC-ESI-MS/MS method and used it to monitor disperse azo dyes in environmental aquatic samples. Calibration curves constructed for nine disperse dyes-Red 1, Violet 93, Blue 373, Orange 1, Orange 3, Orange 25, Yellow 3, Yellow 7 and Red 13-in aqueous solution presented good linearity between 2.0 and 100.0 ng mL(-1). The method provided limits of detection and quantification around 2.0 and 8.0 ng L(-1), respectively. For dyes at concentrations of 25.0 ng mL(-1), the intra- and interday analyses afforded relative standard deviation lower than 6 and 13%, respectively. The recovery values obtained for each target analyte in Milli-Q water, receiving waters and treated water samples spiked with the nine studied dyes at concentrations of 8.0, 25.0 and 50.0 ng L(-1) (n = 3) gave average recoveries greater than 70%, with RSD dyes Disperse Red 1, Disperse Blue 373 and Disperse Violet 93 at concentrations ranging from 84 to 3452 ng L(-1) in the treated effluent (TE), affluent and points collected upstream and downstream of the drinking water treatment plant of a textile dye industry in Brazil. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Water adsorption at high temperature on core samples from The Geysers geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Gruszkiewicz, M.S.; Horita, J.; Simonson, J.M.; Mesmer, R.E.

    1998-06-01

    The quantity of water retained by rock samples taken from three wells located in The Geysers geothermal reservoir, California, was measured at 150, 200, and 250 C as a function of pressure in the range 0.00 {le} p/p{sub 0} {le} 0.98, where p{sub 0} is the saturated water vapor pressure. Both adsorption (increasing pressure) and desorption (decreasing pressure) runs were made in order to investigate the nature and the extent of the hysteresis. Additionally, low temperature gas adsorption analyses were performed on the same rock samples. Nitrogen or krypton adsorption and desorption isotherms at 77 K were used to obtain BET specific surface areas, pore volumes and their distributions with respect to pore sizes. Mercury intrusion porosimetry was also used to obtain similar information extending to very large pores (macropores). A qualitative correlation was found between the surface properties obtained from nitrogen adsorption and the mineralogical and petrological characteristics of the solids. However, there is in general no proportionality between BET specific surface areas and the capacity of the rocks for water adsorption at high temperatures. The results indicate that multilayer adsorption rather than capillary condensation is the dominant water storage mechanism at high temperatures.

  15. Sources of variability in the determination by evaporation method of gross alpha activity in water samples

    International Nuclear Information System (INIS)

    Baeza, A.; Corbacho, J.A.

    2013-01-01

    Determining the gross alpha activity concentration of water samples is one way to screen for waters whose radionuclide content is so high that its consumption could imply surpassing the Total Indicative Dose as defined in European Directive 98/83/EC. One of the most commonly used methods to prepare the sources to measure gross alpha activity in water samples is desiccation. Its main advantages are the simplicity of the procedure, the low cost of source preparation, and the possibility of simultaneously determining the gross beta activity. The preparation of the source, the construction of the calibration curves, and the measurement procedure itself involve, however, various factors that may introduce sufficient variability into the results to significantly affect the screening process. We here identify the main sources of this variability, and propose specific procedures to follow in the desiccation process that will reduce the uncertainties, and ensure that the result is indeed representative of the sum of the activities of the alpha emitters present in the sample. (orig.)

  16. Pumping time required to obtain tube well water samples with aquifer characteristic radon concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Ricardo, Carla Pereira; Oliveira, Arno Heeren de, E-mail: heeren@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Dept. de Engenharia Nuclear; Rocha, Zildete; Palmieri, Helena E.L.; Linhares, Maria G.M.; Menezes, Maria Angela B.C., E-mail: rochaz@cdtn.br, E-mail: help@cdtn.br, E-mail: mgml@cdtn.br, E-mail: menezes@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    Radon is an inert noble gas, which comes from the natural radioactive decay of uranium and thorium in soil, rock and water. Radon isotopes emanated from radium-bearing grains of a rock or soil are released into the pore space. Radon that reaches the pore space is partitioned between the gaseous and aqueous phases. Thus, the groundwater presents a radon signature from the rock that is characteristic of the aquifer. The characteristic radon concentration of an aquifer, which is mainly related to the emanation, is also influenced by the degree of subsurface degassing, especially in the vicinity of a tube well, where the radon concentration is strongly reduced. Looking for the required pumping time to take a tube well water sample that presents the characteristic radon concentration of the aquifer, an experiment was conducted in an 80 m deep tube well. In this experiment, after twenty-four hours without extraction, water samples were collected periodically, about ten minutes intervals, during two hours of pumping time. The radon concentrations of the samples were determined by using the RAD7 Electronic Radon Detector from Durridge Company, a solid state alpha spectrometric detector. It was realized that the necessary time to reach the maximum radon concentration, that means the characteristic radon concentration of the aquifer, is about sixty minutes. (author)

  17. SPME GC/MS determination of organochlorine pesticides in water samples

    Directory of Open Access Journals (Sweden)

    Yerbolat Sailaukhanuly

    2013-05-01

    Full Text Available Headspace solid phase microextraction (HS-SPME in combination with gas chromatography and mass-spectrometry (GC/MS was studied for analysis of water samples. The organochlorine pesticides (OCPs, p,p'-DDT, p,p'-DDD, and p,p'-DDE were collected and analyzed by GC/MS. To select of effective fiber coatings four types of SPME fibers were examined and compared. The parameters effecting the efficiency of HS-SPME such as extraction and pre-incubation time and extraction temperature, effect of solvent nature, ionic strength were studied to obtain optimal parameters. The method was developed using spiked water samples in a concentration range  10 - 500 ng/L. The calibration curve was linear over the studied concentration range with r≥0.9925. The detection limits varied from 1.57 to 2.08 ng/L. An authentic water samples from contaminated lake with OCPs were analyzed by developed method.

  18. Temperature dependence of the calibration factor of radon and radium determination in water samples by SSNTD

    CERN Document Server

    Hunyadi, I; Hakl, J; Baradacs, E; Dezso, Z

    1999-01-01

    The sensitivity of a sup 2 sup 2 sup 6 Ra determination method of water samples by SSNTD was measured as a function of storage temperature during exposure. The method is based on an etched track type radon monitor, which is closed into a gas permeable foil and is immersed in the water sample. The sample is sealed in a glass vessel and stored for an exposure time of 10-30 days. The sensitivity increased more than a factor of two when the storage temperature was raised from 2 deg. C to 30 deg. C. Temperature dependence of the partition coefficient of radon between water and air provides explanation for this dependence. For practical radio- analytical application the temperature dependence of the calibration factor is given by fitting the sensitivity data obtained by measuring sup 2 sup 2 sup 6 Ra standard solutions (in the activity concentration range of 0.1-48.5 kBq m sup - sup 3) at different storage temperatures.

  19. Pumping time required to obtain tube well water samples with aquifer characteristic radon concentrations

    International Nuclear Information System (INIS)

    Ricardo, Carla Pereira; Oliveira, Arno Heeren de

    2011-01-01

    Radon is an inert noble gas, which comes from the natural radioactive decay of uranium and thorium in soil, rock and water. Radon isotopes emanated from radium-bearing grains of a rock or soil are released into the pore space. Radon that reaches the pore space is partitioned between the gaseous and aqueous phases. Thus, the groundwater presents a radon signature from the rock that is characteristic of the aquifer. The characteristic radon concentration of an aquifer, which is mainly related to the emanation, is also influenced by the degree of subsurface degassing, especially in the vicinity of a tube well, where the radon concentration is strongly reduced. Looking for the required pumping time to take a tube well water sample that presents the characteristic radon concentration of the aquifer, an experiment was conducted in an 80 m deep tube well. In this experiment, after twenty-four hours without extraction, water samples were collected periodically, about ten minutes intervals, during two hours of pumping time. The radon concentrations of the samples were determined by using the RAD7 Electronic Radon Detector from Durridge Company, a solid state alpha spectrometric detector. It was realized that the necessary time to reach the maximum radon concentration, that means the characteristic radon concentration of the aquifer, is about sixty minutes. (author)

  20. Analytical methods for the endocrine disruptor compounds determination in environmental water samples.

    Science.gov (United States)

    Locatelli, Marcello; Sciascia, Francesco; Cifelli, Roberta; Malatesta, Luciano; Bruni, Pantaleone; Croce, Fausto

    2016-02-19

    The potential risk of exposure to different xenobiotics, which can modulate the endocrine system and represent a treat for the wellness of an increasing number of people, has recently drawn the attention of international environmental and health agencies. Several agents, characterized by structural diversity, may interfer with the normal endocrine functions that regulate cell growth, homeostasis and development. Substances such as pesticides, herbicides, plasticizers, metals, etc. having endocrine activity (EDCs) are used in agriculture and industry and are also used as drugs for humans and animals. A difficulty in the analytical determination of these substances is the complexity of the matrix in which they are present. In fact, the samples most frequently analyzed consist of groundwater and surface water, including influent and effluent of wastewater treatment plants and drinking water. In this review, several sample pretreatment protocols, assays and different instrumental techniques recently used in the EDCs determination have been considered. This review concludes with a paragraph in which the most recent hyphenated-instrument techniques are treated, highlighting their sensitivity and selectivity for the analyses of environmental water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Development of radiochemical methods for the determination of radionuclides in water samples

    International Nuclear Information System (INIS)

    Vajda, N.; Molnar, Zs.; Bodizs, D.

    2004-01-01

    are high, in the range of 10 -4 -10 -6 Bq/L. 90 Sr and Pu nuclides have been determined in the surveillance wells of the Hungarian nuclear power plant for several years. Ground level measurements have been performed in the area of the future radioactive waste disposal site. Radionuclides of natural origin have typically significantly higher concentrations than those of artificial nuclides, thus methods of moderate sensitivities have been developed/adopted for the determination of U and Th as well as Ra and Po isotopes. Uranium and thorium are separated in a combined procedure by extraction chromatography using an organic phosphonate compound. Ra and Po are consecutively separated from the same sample aliquot, Po is spontaneously deposited onto Ag disc, while from the supernate Ra is co-precipitated with Ba sulfate. Alpha spectrometry is used for the sensitive detection of 238 U, 235 U, 234 U, 232 Th, 230 Th, 228 Th, 210 Po and 226 Ra. Analyzing 100-1000 ml water samples detection limits in the range of 10 -2 -10 -4 Bq/L were obtained. The procedure has been successfully applied for ground level determination in tile area of the future radioactive waste disposal site in Hungary. To increase the accuracy of each method radioactive tracers or stable carriers were added to each sample/each analyte before chelnical processing and results were corrected for chemical losses. Methods were validated by measuring reference materials and performing proficiency tests. (authors)

  2. Application of polydimethylsiloxane rod extraction to the determination of sixteen halogenated flame retardants in water samples.

    Science.gov (United States)

    Valls-Cantenys, Carme; Villaverde-de-Sáa, Eugenia; Rodil, Rosario; Quintana, José Benito; Iglesias, Mònica; Salvadó, Victòria; Cela, Rafael

    2013-04-03

    An extraction and preconcentration procedure for the determination in water samples of several halogenated flame retardants (FRs), nine brominated diphenyls ethers (BDEs) and seven non-BDE FRs, was developed and validated. The optimised procedure is based on polydimethylsiloxane (PDMS) rods as sorptive extraction material, followed by liquid desorption and gas chromatography coupled to negative chemical ionisation-mass spectrometry (GC-NCI-MS) determination, rendering an efficient and inexpensive method. The final optimised protocol consists of overnight extraction of 100mL of sample solutions containing 40% MeOH and 4% NaCl, followed by a 15-min sonication-assisted desorption with 300 μL of ethyl acetate, solvent evaporation and GC-NCI-MS analysis. Under these conditions, extraction efficiencies in the 9 to 70% range were obtained, leading to enrichment factors between 108 and 840, detection limits in the range from 0.4 to 10 ng L(-1)and RSD values in the 2-23% range. After method validation, different real water samples, including river, ria, sea, landfill leachate, influent and effluent wastewater from an urban sewage treatment plant (STP) and effluent wastewater from a textile industry, were analysed. BDE-47, BDE-99, BDE-100 and BDE-197 were detected in wastewater and landfill leachate samples at concentration levels up to 2887 ng L(-1). Among the non-BDE FRs, bis (2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate (DEHTBP) was detected in surface water samples (sea, river and ria) between 1.3 and 2.2 ng L(-1) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) in the landfill leachate (64 ng L(-1)). Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Use of passive sampling devices for monitoring and compliance checking of POP concentrations in water.

    Science.gov (United States)

    Lohmann, Rainer; Booij, Kees; Smedes, Foppe; Vrana, Branislav

    2012-07-01

    The state of the art of passive water sampling of (nonpolar) organic contaminants is presented. Its suitability for regulatory monitoring is discussed, with an emphasis on the information yielded by passive sampling devices (PSDs), their relevance and associated uncertainties. Almost all persistent organic pollutants (POPs) targeted by the Stockholm Convention are nonpolar or weakly polar, hydrophobic substances, making them ideal targets for sampling in water using PSDs. Widely used nonpolar PSDs include semi-permeable membrane devices, low-density polyethylene and silicone rubber. The inter-laboratory variation of equilibrium partition constants between PSD and water is mostly 0.2-0.5 log units, depending on the exact matrix used. The sampling rate of PSDs is best determined by using performance reference compounds during field deployment. The major advantage of PSDs over alternative matrices applicable in trend monitoring (e.g. sediments or biota) is that the various sources of variance including analytical variance and natural environmental variance can be much better controlled, which in turn results in a reduction of the number of analysed samples required to obtain results with comparable statistical power. Compliance checking with regulatory limits and analysis of temporal and spatial contaminant trends are two possible fields of application. In contrast to the established use of nonpolar PSDs, polar samplers are insufficiently understood, but research is in progress to develop PSDs for the quantitative assessment of polar waterborne contaminants. In summary, PSD-based monitoring is a mature technique for the measurement of aqueous concentrations of apolar POPs, with a well-defined accuracy and precision.

  4. Sampling method of water sources at study site Taiping, Perak and Pulau Burung, Penang for research on pollutant movement in underground water

    International Nuclear Information System (INIS)

    Mohd Rifaie Mohd Murtadza; Mohd Tadza Abdul Rahman; Kamarudin Samuding; Roslanzairi Mostapa

    2005-01-01

    This paperwork explain the method of water sampling being used to take the water samples from the study sites in Taiping, Perak and Pulau Burung, Pulau Pinang. The sampling involve collecting of water samples for groundwater from boreholes and surface water from canal, river, pond, and ex-mining pond from several locations at the study sites. This study also elaborates the instruments and chemical used. The main purpose of this sampling are to obtain the important water quality parameters such as pH, conductivity, Total Dissolved Solid (TDS), heavy metals, anions, cations, and environmental isotopes delta values (d) for 18O, Deuterium dan Tritium. A correct sampling method according to standard is very important to ensure an accurate and precise results. With this, the data from the laboratory tests result can be fully utilized to make the interpretation of the pollutants movement. (Author)

  5. Quantification of ziram and zineb residues in fog-water samples.

    Science.gov (United States)

    Agarwal, Smita; Aggarwal, Shankar G; Singh, Pahup

    2005-01-15

    The present paper describes the extractive quantification of zinc-dithiocarbamate fungicides, i.e. ziram (zinc bis-dimethyldithiocarbamate) and zineb (zinc ethylene-1,2-bis-dithiocarbamate) in fog-water samples. The method is based on the releasing of equivalent amount of zinc from the fungicides and its subsequent determination by visible spectrophotometry or by flame-atomic absorption spectrometry (flame-AAS). For spectrophotometry, the sample contained up to 48mug of ziram and 42mug of zineb was first equilibrated with chloroform. The recovery results show that only ziram content was extracted into chloroform. Then, the sample was treated with NH(4)SCN and surfactants (i.e. CPC and TX-100) solutions, and extracted with toluene to remove interference of inorganic zinc and other metal ions, if present in the sample. The residue was further used for zineb determination. The chloroform extract and residue were then digested separately with nitric acid to release Zn(II), which were then analyzed spectrophotometerically with 4-(2-pyridylazo)-resorcinol in the micellar medium (TX-100) for the determination of ziram and zineb, respectively. The complex shows lambda(max) at 495nm. The molar absorptivity in terms of ziram/zineb was determined to be (8.05) x 10(4)Lmole(-1)cm(-1). The detection limits for ziram and zineb were calculated to be 20 and 21mugL(-1) (with R.S.D. fog-water.

  6. Evidence of microplastics in samples of zooplankton from Portuguese coastal waters.

    Science.gov (United States)

    Frias, J P G L; Otero, V; Sobral, P

    2014-04-01

    Records of high concentrations of plastic and microplastic marine debris floating in the ocean have led to investigate the presence of microplastics in samples of zooplankton from Portuguese coastal waters. Zooplankton samples collected at four offshore sites, in surveys conducted between 2002 and 2008, with three different sampling methods, were used in this preliminary study. A total of 152 samples were processed and microplastics were identified in 93 of them, corresponding to 61% of the total. Costa Vicentina, followed by Lisboa, were the regions with higher microplastic concentrations (0.036 and 0.033 no. m⁻³) and abundances (0.07 and 0.06 cm³ m⁻³), respectively. Microplastic: zooplankton ratios were also higher in these two regions, which is probably related to the proximity of densely populated areas and inputs from the Tejo and Sado river estuaries. Microplastics polymers were identified using Micro Fourier Transformed Infrared Spectroscopy (μ-FTIR), as polyethylene (PE), polypropylene (PP) and polyacrylates (PA). The present work is the first report on the composition of microplastic particles collected with plankton nets in Portuguese coastal waters. Plankton surveys from regular monitoring campaigns conducted worldwide may be used to monitor plastic particles in the oceans and constitute an important and low cost tool to address marine litter within the scope of the Marine Strategy Framework Directive (2008/56/EC). Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. UMTRA project water sampling and analysis plan, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    1994-02-01

    This water sampling and analysis plan (WSAP) provides the basis for ground water sampling at the Ambrosia Lake Uranium Mill Tailings Remedial Action (UMTRA) Project site during fiscal year 1994. It identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the monitoring locations and will be updated annually. The Ambrosia Lake site is in McKinley County, New Mexico, about 40 kilometers (km) (25 miles [mi]) north of Grants, New Mexico, and 1.6 km (1 mi) east of New Mexico Highway 509 (Figure 1.1). The town closest to the tailings pile is San Mateo, about 16 km ( 10 mi) southeast (Figure 1.2). The former mill and tailings pile are in Section 28, and two holding ponds are in Section 33, Township 14 North, Range 9 West. The site is shown on the US Geological Survey (USGS) map (USGS, 1980). The site is approximately 2100 meters (m) (7000 feet [ft]) above sea level

  8. Detection of toxic compounds in real water samples using a conductometric tyrosinase biosensor

    International Nuclear Information System (INIS)

    Anh, Tuan Mai; Dzyadevych, Sergei V.; Prieur, Nicolas; Duc, Chien Nguyen; Pham, T.D.; Renault, Nicole Jaffrezic; Chovelon, Jean-Marc

    2006-01-01

    A conductometric tyrosinase biosensor for the detection of some toxic compounds including diuron, atrazine, and copper ions was developed. The work of this biosensor is based on the principle of change of conductivity of the enzyme membrane when tyrosinase either interacts with 4-chlorophenol substrate or is inhibited by pollutants. The different samples tested were solutions containing diuron, atrazine, copper, lead and zinc ions, mixtures of copper/atrazine or copper/diuron and real water samples coming from a Vietnamese river. In the last case, classical techniques such as GC-MS or atomic absorption spectrometry were used in order to estimate exact concentration of these species in real water samples. Results have shown that such a biosensor could be used as an early warning system for the detection of these pollutants, as no matrix effect coming from the real sample was observed and no synergetic or antagonist effects were found for the mixture of toxic compounds. In addition, results were coherent with the content of the tyrosinase inhibitors

  9. Detection of toxic compounds in real water samples using a conductometric tyrosinase biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Anh, Tuan Mai [Laboratoire d' Application de la Chimie a l' Environnement, UMR CNRS 5634, Universite Claude Bernard Lyon I, 43 Boulevard du 11 Nov. 1918, 69622 Villeurbanne Cedex (France); International Training Institute for Materials Science (ITIMS), Hanoi University of Technology, 1 Dai Co Viet, Hanoi, Vietnam (Viet Nam); Dzyadevych, Sergei V. [Laboratory of Biomolecular Electronics, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150 Zabolotnogo Str., Kiev 03143 (Ukraine); Prieur, Nicolas [Institute of Natural Products Chemistry, Vietnam National Centre for Science and Technology, Hoang Quoc Viet Str., Hanoi, Vietnam (Viet Nam); Duc, Chien Nguyen [International Training Institute for Materials Science (ITIMS), Hanoi University of Technology, 1 Dai Co Viet, Hanoi, Vietnam (Viet Nam); Pham, T.D. [International Training Institute for Materials Science (ITIMS), Hanoi University of Technology, 1 Dai Co Viet, Hanoi, Vietnam (Viet Nam); Renault, Nicole Jaffrezic [Ecole Centrale de Lyon, CEGELY, UMR CNRS 5005, 36 Avenue Guy de Collongue, 69134 Ecully Cedex (France); Chovelon, Jean-Marc [Laboratoire d' Application de la Chimie a l' Environnement, UMR CNRS 5634, Universite Claude Bernard Lyon I, 43 Boulevard du 11 Nov. 1918, 69622 Villeurbanne Cedex (France)]. E-mail: chovelon@univ-lyon1.fr

    2006-03-15

    A conductometric tyrosinase biosensor for the detection of some toxic compounds including diuron, atrazine, and copper ions was developed. The work of this biosensor is based on the principle of change of conductivity of the enzyme membrane when tyrosinase either interacts with 4-chlorophenol substrate or is inhibited by pollutants. The different samples tested were solutions containing diuron, atrazine, copper, lead and zinc ions, mixtures of copper/atrazine or copper/diuron and real water samples coming from a Vietnamese river. In the last case, classical techniques such as GC-MS or atomic absorption spectrometry were used in order to estimate exact concentration of these species in real water samples. Results have shown that such a biosensor could be used as an early warning system for the detection of these pollutants, as no matrix effect coming from the real sample was observed and no synergetic or antagonist effects were found for the mixture of toxic compounds. In addition, results were coherent with the content of the tyrosinase inhibitors.

  10. Solid phase extraction for determination of 90Sr in water sample

    International Nuclear Information System (INIS)

    Ometakova, J.

    2009-01-01

    We studied the use of an extraction chromatography for determination of 90 Sr in samples of contaminated water. The aim of the thesis was to compare selected products from the point of view of the strontium yields and time needed. Three commercial products: 3M Empore Strontium Rad Disk, AnaLig, Sr-Resin and two classical methods: liquid-liquid extraction with tributylphosphate and carbonate co-precipitation (to eliminate interferers) were used for separation of 90 Sr. The water sample was used in radiochemical analysis for determination volume activity of 90 Sr. A radiochemical strontium yield was traced by using radionuclide 85 Sr. Samples were counted over a two week period to monitor the ingrowth of 90 Y on TRI CARB LSC counter. Samples were measured using an HPGe detector to find out 85 Sr recoveries at 514 keV line and they were counted directly by Cherenkov counting after the growth of 90 Y using TriCarb LSC counter after a two- week period (author)

  11. The measurement of tritium in water samples with electrolytic enrichment using liquid scintillation counter

    Directory of Open Access Journals (Sweden)

    Janković Marija M.

    2012-01-01

    Full Text Available Tritium (3H present in the environment decreased in the last decades and nowadays it has low activity concentrations. Measurement of low-level tritium activities in natural waters, e. g. in precipitation, groundwater, and river water requires special techniques for water pretreatment and detection of low-level radioactivity. In order to increase the tritium concentration to an easily measurable level, electrolytic enrichment must be applied. This paper presents the enrichment method performed by electrolysis in a battery of 18 cells, giving an enrichment factor of 5.84 (calculated from 59 electrolyses. The calculated mean values of the separation factor and enrichment parameter were 4.10 and 0.84, respectively. Results for tritium activity in precipitation and surface water collected in Belgrade during 2008 and 2009 are presented. The Radiation and Environmental Protection Department of the Vinča Institute of Nuclear Sciences, participated in the IAEA TRIC2008 international intercomparison exercise. The participation in the intercomparisons for any laboratory doing low-level 3H measurements in the waters is very important and useful. It is considered the best way to check the entire procedure and methods of the measurements and the reliability of the standard used. The analysis of the reported 3H activity results showed that all results for five intercomparison samples, for which electrolytic enrichment were applied prior to the 3H measurement, are acceptable.

  12. Cost-effective sampling of ground water monitoring wells. Revision 1

    International Nuclear Information System (INIS)

    Ridley, M.; Johnson, V.

    1995-11-01

    CS is a systematic methodology for estimating the lowest-frequency sampling schedule for a given groundwater monitoring location which will still provide needed information for regulatory and remedial decision-making. Increases in frequency dictated by remedial actions are left to the judgement of personnel reviewing the recommendations. To become more applicable throughout the life cycle of a ground water cleanup project or for compliance monitoring, several improvements are envisioned, including: chemical signature analysis to identify minimum suites of contaminants for a well, a simple flow and transport model so that sampling of downgradient wells are increased before movement of contamination, and a sampling cost estimation capability. By blending qualitative and quantitative approaches, we hope to create a defensible system while retaining interpretation ease and relevance to decision making

  13. Radium 226 and uranium isotopes simultaneously determination in water samples using liquid scintillation counter

    International Nuclear Information System (INIS)

    Al-Masri, M.S.; Al-Akel, B.; Saaid, S.; Nashawati, A.

    2007-04-01

    In this work a method has been developed to determine simultaneously Radium 226 and Uranium isotopes in water samples by low back ground Liquid Scintillation Counter. Radium 226 was determined by its progeny Polonium 214 after one month of sample storage in order to achieve the equilibrium between Radium 226 and Polonium 214. Uranium isotopes were determined by subtracting Radium 226 activity from total alpha activity. The method detection limits were 0.049 Bq/L and 0.176 Bq/L for Radium 226 and Uranium isotopes respectively. The repeatability limits were ± 0.32 Bq/L and ± 0.9 Bq/L for Radium 226 and Uranium isotopes respectively. While relative errors were % 9.5 and %18.2 for Radium 226 and Uranium isotopes respectively. On the other hand, the report presented the results of different standard and natural samples.(author)

  14. Analysis and evaluation of compounds from Cichorium intybus aromatic water trade market samples

    Directory of Open Access Journals (Sweden)

    A. Hosseini*

    2017-11-01

    Full Text Available Background and objectives: Cichorium intybus products are one of the best sellers in market Because of their effect on treatment of infection, poisoning, diabetes and allergy. This is the first study about Cichorium intybus market samplephytochemical compounds and the aim of this study was to define a method to recognize the original products. Methods: The sample compounds were extracted by liquid-liquid method and evaluated by GC-MS and compared with the references like Adams 2007. The obtained phytochemical data were analyzed with SPSS and classified by dendrogram method and was compared with the data earned from the standard sample. Results: Forty one compounds were detected. Carvacrol was available in all samples from 1.14 to 39.34%. Also, thymol was present in most of samples from 1.24 to 69.32%. Moreover, we understood that some compounds like pulegone, carvone, carvacrol and piperitenone could be detected in all samples mostly with different percentages. Some linear hydrocarbon was detected in this method along with some other unexpected compounds like cinnamaldehyde. Conclusion: Existence of some impure compounds like: pulegone, carvone, piperitenone and cinnamaldehyde in trade samples showed cleaning of container might not have been proper. Carvacrol and thymol are common compounds to define acceptable standard for Cichorium intybus aromatic water.

  15. High-frequency, long-duration water sampling in acid mine drainage studies: a short review of current methods and recent advances in automated water samplers

    Science.gov (United States)

    Chapin, Thomas

    2015-01-01

    Hand-collected grab samples are the most common water sampling method but using grab sampling to monitor temporally variable aquatic processes such as diel metal cycling or episodic events is rarely feasible or cost-effective. Currently available automated samplers are a proven, widely used technology and typically collect up to 24 samples during a deployment. However, these automated samplers are not well suited for long-term sampling in remote areas or in freezing conditions. There is a critical need for low-cost, long-duration, high-frequency water sampling technology to improve our understanding of the geochemical response to temporally variable processes. This review article will examine recent developments in automated water sampler technology and utilize selected field data from acid mine drainage studies to illustrate the utility of high-frequency, long-duration water sampling.

  16. Tritium analysis in environmental samples around Nuclear Power Plants and nationwide surveillance of radionuclides in some environmental samples(meat and drinking water)

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Woo; Han, Man Jung; Cho, Seong Won; Cho, Hong Jun; Oh, Hyeon Kyun; Lee, Jeong Min; Chang, Jae Sook [KORTIC, Taejon (Korea, Republic of)

    2001-12-15

    12 kind of environmental samples such as soil, underground water, seawater, etc. around the Nuclear Power Plants(NPP) and surface seawater around the Korea peninsula were sampled, For the samples of rain, pine-needle, air, seawater, underground water, chinese cabbage, grain of rice and milk sampled around NPP, and surface seawater and rain sampled all around country, tritium concentration was measured, The tritium concentration in the tap water and the gamma activity in the domestic and imported beef that were sampled at ward in the large city in Korea(Seoul, Pusan, Taegu, Taejun, Inchun, Kwangju) were analyzed for the meat and drinking waters. As the results of analyzing, tritium concentration in rain and tap water were very low all around country, but a little higher around the NPP than general surrounding. At the Wolsung NPP, tritium concentration was descend according to distance from the stack. Tritium activity of surface seawater around the Korea peninsula was also, very low. The measured radioactive elements in the beef is the same as the radioactive elements on the earth surface.

  17. Micro-TLC Approach for Fast Screening of Environmental Samples Derived from Surface and Sewage Waters.

    Science.gov (United States)

    Zarzycki, Paweł K; Slączka, Magdalena M; Włodarczyk, Elżbieta; Baran, Michał J

    2013-01-01

    In this work we demonstrated analytical capability of micro-planar (micro-TLC) technique comprising one and two-dimensional (2D) separation modes to generate fingerprints of environmental samples originated from sewage and ecosystems waters. We showed that elaborated separation and detection protocols are complementary to previously invented HPLC method based on temperature-dependent inclusion chromatography and UV-DAD detection. Presented 1D and 2D micro-TLC chromatograms of SPE (solid-phase extraction) extracts were optimized for fast and low-cost screening of water samples collected from lakes and rivers located in the area of Middle Pomerania in northern part of Poland. Moreover, we studied highly organic compounds loaded in the treated and untreated sewage waters obtained from municipal wastewater treatment plant "Jamno" near Koszalin City (Poland). Analyzed environmental samples contained number of substances characterized by polarity range from estetrol to progesterone as well as chlorophyll-related dyes previously isolated and pre-purified by simple SPE protocol involving C18 cartridges. Optimization of micro-TLC separation and quantification protocols of such samples were discussed from the practical point of view using simple separation efficiency criteria including total peaks number, log(product Δ hR F ), signal intensity and peak asymmetry. Outcomes of the presented analytical approach, especially using detection involving direct fluorescence (UV366/Vis) and phosphomolybdic acid (PMA) visualization are compared with UV-DAD HPLC-generated data reported previously. Chemometric investigation based on principal components analysis revealed that SPE extracts separated by micro-TLC and detected under fluorescence and PMA visualization modes can be used for robust sample fingerprinting even after long-term storage of the extracts (up to 4 years) at subambient temperature (-20 °C). Such approach allows characterization of wide range of sample components

  18. Detection of Escherichia coli in Biofilms from Pipe Samples and Coupons in Drinking Water Distribution Networks▿

    Science.gov (United States)

    Juhna, T.; Birzniece, D.; Larsson, S.; Zulenkovs, D.; Sharipo, A.; Azevedo, N. F.; Ménard-Szczebara, F.; Castagnet, S.; Féliers, C.; Keevil, C. W.

    2007-01-01

    Fluorescence in situ hybridization (FISH) was used for direct detection of Escherichia coli on pipe surfaces and coupons in drinking water distribution networks. Old cast iron main pipes were removed from water distribution networks in France, England, Portugal, and Latvia, and E. coli was analyzed in the biofilm. In addition, 44 flat coupons made of cast iron, polyvinyl chloride, or stainless steel were placed into and continuously exposed to water on 15 locations of 6 distribution networks in France and Latvia and examined after 1 to 6 months exposure to the drinking water. In order to increase the signal intensity, a peptide nucleic acid (PNA) 15-mer probe was used in the FISH screening for the presence or absence of E. coli on the surface of pipes and coupons, thus reducing occasional problems of autofluorescence and low fluorescence of the labeled bacteria. For comparison, cells were removed from the surfaces and examined with culture-based or enzymatic (detection of β-d-glucuronidase) methods. An additional verification was made by using PCR. Culture method indicated presence of E. coli in one of five pipes, whereas all pipes were positive with the FISH methods. E. coli was detected in 56% of the coupons using PNA FISH, but no E. coli was detected using culture or enzymatic methods. PCR analyses confirmed the presence of E. coli in samples that were negative according to culture-based and enzymatic methods. The viability of E. coli cells in the samples was demonstrated by the cell elongation after resuscitation in low-nutrient medium supplemented with pipemidic acid, suggesting that the cells were present in an active but nonculturable state, unable to grow on agar media. E. coli contributed to ca. 0.001 to 0.1% of the total bacterial number in the samples. The presence and number of E. coli did not correlate with any of physical and/or chemical characteristic of the drinking water (e.g., temperature, chlorine, or biodegradable organic matter concentration

  19. Posterior or Single-stage Combined Anterior and Posterior Approach Decompression for Treating Complex Cervical Spondylotic Myelopathy Coincident Multilevel Anterior and Posterior Compression.

    Science.gov (United States)

    Zhou, Xiaoxiao; Cai, Pan; Li, Yuwei; Wang, Haijiao; Xia, Shengli; Wang, Xiuhui

    2017-12-01

    A single-center, retrospective, longitudinal matched cohort clinical study of prospectively collected outcomes. To compare retrospectively the clinical outcomes and complications of the posterior approach laminoplasty and single-stage anterior approach laminoplasty combined with anterior cervical corpectomy and fusion and anterior cervical discectomy and fusion for treating patients with cervical spondylotic myelopathy coincident multilevel anterior and posterior compression, known as complex cervical spondylotic myelopathy (cCSM) here. The optimal surgical management of this type of cCSM remains controversial. Sixty-seven patients with multilevel cCSM underwent decompression surgery from 1996 to 2007. Among these patients, 31 underwent a single-stage combined approach with decompression (combined approach group) and 36 underwent laminoplasty for posterior approach (posterior approach group). Average operative duration, operative estimated blood loss, surgical costs, and cervical alignment were measured. Average operative duration, operative estimated blood loss, and surgical costs were significantly lower in the posterior approach group than those in the combined approach group (P0.05). No statistical difference was observed in the preoperative Cobb angle (P>0.05), whereas a significant statistical difference was observed for the postoperative Cobb angle (Pgroups. The surgical incidences of complications were 22.2% and 48.4% in the posterior and combined approach groups (Papproach laminoplasty and single-stage combined approach led to significant neurological improvement and pain reduction in the majority of patients. Both approaches showed similar results in terms of decompression and neurological improvement. The posterior approach was superior to the combined approach in terms of surgical costs, surgical time, blood loss, and complication rate.

  20. Retrospective analysis of 56 edentulous dental arches restored with 344 single-stage implants using an immediate loading fixed provisional protocol: statistical predictors of implant failure.

    Science.gov (United States)

    Kinsel, Richard P; Liss, Mindy

    2007-01-01

    The purpose of this retrospective study was to evaluate the effects of implant dimensions, surface treatment, location in the dental arch, numbers of supporting implant abutments, surgical technique, and generally recognized risk factors on the survival of a series of single-stage Straumann dental implants placed into edentulous arches using an immediate loading protocol. Each patient received between 4 and 18 implants in one or both dental arches. Periapical radiographs were obtained over a 2- to 10-year follow-up period to evaluate crestal bone loss following insertion of the definitive metal-ceramic fixed prostheses. Univariate tests for failure rates as a function of age ( or = 60 years), gender, smoking, bone grafting, dental arch, surface type, anterior versus posterior, number of implants per arch, and surgical technique were made using Fisher exact tests. The Cochran-Armitage test for trend was used to evaluate the presence of a linear trend in failure rates regarding implant length and implant diameter. Logistic regression modeling was used to determine which, if any, of the aforementioned factors would predict patient and implant failure. A significance criterion of P = .05 was utilized. Data were collected for 344 single-stage implants placed into 56 edentulous arches (39 maxillae and 17 mandibles) of 43 patients and immediately loaded with a 1-piece provisional fixed prosthesis. A total of 16 implants failed to successfully integrate, for a survival rate of 95.3%. Increased rates of failure were associated with reduced implant length, placement in the posterior region of the jaw, increased implant diameter, and surface treatment. Implant length emerged as the sole significant predictor of implant failure. In this retrospective analysis of 56 consecutively treated edentulous arches with multiple single-stage dental implants loaded immediately, reduced implant length was the sole significant predictor of failure.

  1. Submarine groundwater discharge derived strontium from the Bengal Basin traced in Bay of Bengal water samples.

    Science.gov (United States)

    Chakrabarti, Ramananda; Mondal, Surajit; Acharya, Shiba Shankar; Lekha, J Sree; Sengupta, Debasis

    2018-03-12

    Evaluating the submarine groundwater discharge (SGD) derived strontium (Sr) flux from the Bengal Basin to the Bay of Bengal (BoB) and determining its isotopic composition is crucial for understanding the marine Sr isotopic evolution over time. Measurements of spatially and temporally distributed water samples collected from the BoB show radiogenic 87 Sr/ 86 Sr, high Sr, calcium (Ca) concentrations and high salinity in samples collected dominantly from 100-120 m depth, which can be explained only by the contribution of saline groundwater from the Bengal Basin. These results provide a direct evidence of the SGD-Sr flux to the BoB. This SGD-Sr flux is however, spatially heterogeneous and using conservative hydrological estimates of the SGD flux to the BoB, we suggest a SGD Sr flux of 13.5-40.5 × 10 5 mol/yr to the BoB. Mass balance calculations using Sr concentrations and 87 Sr/ 86 Sr suggest up to 7% contribution of SGD to the 100-120 m BoB water samples. The identification of SGD at 100-120 m depth also provides an explanation for the anomalous variations in barium (Ba) concentrations and the δ 18 O-salinity relationship in intermediate depths of the BoB.

  2. Microporous Carbon Spheres Solid Phase Membrane Tip Extraction for the Analysis of Nitrosamines in Water Samples

    International Nuclear Information System (INIS)

    Mohammed Salisu Musa; Wan Aini Wan Ibrahim

    2015-01-01

    A simple solid phase membrane tip extraction (SPMTE) utilizing microporous carbon spheres (MCS) was developed for the analysis of nitrosamines in aqueous samples. The method termed MCS-SPMTE was optimized for various important extraction parameters namely conditioning organic solvent, extraction time, effects of salt addition and pH change, desorption time, desorption solvent and sample volume. Under the optimized conditions, the method indicated good linearity in the range of 10-100 μg/ L with coefficients of determination, r 2 ≥0.9984. The method also demonstrated good reproducibility with % RSDs values ranging from 2.2 - 8.9 (n = 3). Limit of detection (LOD) and limit of quantification (LOQ) for the method ranged from 3.2 - 4.8 μg/ L and 10.9 - 15.9 μg/L respectively. Recoveries for both tap-water and lake water samples spiked at 10 μg/L were in the range of 83.2 - 107.5 %. (author)

  3. Arsenic speciation in natural water samples by coprecipitation-hydride generation atomic absorption spectrometry combination.

    Science.gov (United States)

    Tuzen, Mustafa; Citak, Demirhan; Mendil, Durali; Soylak, Mustafa

    2009-04-15

    A speciation procedure for As(III) and As(V) ions in environmental samples has been presented. As(V) was quantitatively recovered on aluminum hydroxide precipitate. After oxidation of As(III) by using dilute KMnO(4), the developed coprecipitation was applied to determination of total arsenic. Arsenic(III) was calculated as the difference between the total arsenic content and As(V) content. The determination of arsenic levels was performed by hydride generation atomic absorption spectrometry (HG-AAS). The analytical conditions for the quantitative recoveries of As(V) including pH, amount of aluminum as carrier element and sample volume, etc. on the presented coprecipitation system were investigated. The effects of some alkaline, earth alkaline, metal ions and also some anions were also examined. Preconcentration factor was calculated as 25. The detection limits (LOD) based on three times sigma of the blank (N: 21) for As(V) was 0.012 microg L(-1). The satisfactory results for the analysis of arsenic in NIST SRM 2711 Montana soil and LGC 6010 Hard drinking water certified reference materials for the validation of the method was obtained. The presented procedure was successfully applied to real samples including natural waters for arsenic speciation.

  4. Study of lead pollution in air, soil and water samples of Quetta city

    International Nuclear Information System (INIS)

    Khan, M.; Khan, G.M.; Akbar, S.; Panezai, M.A.; Haq, Z.U.

    2011-01-01

    This study briefly presents the collected data of lead pollution in the environment of Quetta City in Balochistan, Pakistan. The samples were collected from different sites. The analysis of lead was carried out in underground water samples, the exhaust of different vehicles, roadside and sewage soils from selected points of Quetta City. The average discharge resulted in deposition by motorcycles (29.12 g/h), cars (44.47 g/h), wagons (176.54 g/h) and buses (141.52 g/h). The maximum deposition was 222.96 g/h from auto-rickshaws. The value for lead in smoke of different vehicles seems quite high when extrapolated to the large number of such vehicles for a longer time. The concentration of lead in roadside soil varied from 73.3 mg/kg (T and T closed colony) to 731.9 mg/kg (Sirki road bus-stop). The average content of lead in sewage soil of City Nala is 1250.6 mg/kg. The level of lead was more than WHO standards for such soils. The lead quantity in all 24 tube- well water samples, was slightly above the WHO standards (10 macro g/L).The results of this study were comparable to similar study in twin cities of Rawalpindi and islamabad. (author)

  5. Ten years of radiometric monitoring in water samples in Uruguay potables plants

    International Nuclear Information System (INIS)

    Perruni, P.

    2000-01-01

    The work exposes the summary of having been radiometrics obtained during the last 10 years in several water treatment plants of the national territory, with the purpose of determining if in the total dose to the one that this exposed one naturally the population of the country, is important the contribution of polluting radioactives in the drinkable water, in function of the geographical area and the time of the year. The investigation is framed inside the Program of Control Radiometrics of Products of Fission in waters, floors, foods and aerosols of the Uruguay developed by the Radiochemistry Department, of the Nuclear Research Center, Montevideo (UY) The samples of water filter, they process and they analyze according to laboratory protocols, had duplicated by each plant, parallel with radio-active, white bottom measures and standards. The results net average obtained for each factory, gave below the one it limits of detection: 2 BQ/Kg for geometry Marinelli and 0.02 BQ/g for plane geometry, with 99,3% of dependability (standard 3 deviations), very below the maximum values admitted by International Organisms (WHO, FAO, ICRP) [es

  6. Solid phase extraction for the speciation and preconcentration of inorganic selenium in water samples: a review.

    Science.gov (United States)

    Herrero Latorre, C; Barciela García, J; García Martín, S; Peña Crecente, R M

    2013-12-04

    Selenium is an essential element for the normal cellular function of living organisms. However, selenium is toxic at concentrations of only three to five times higher than the essential concentration. The inorganic forms (mainly selenite and selenate) present in environmental water generally exhibit higher toxicity (up to 40 times) than organic forms. Therefore, the determination of low levels of different inorganic selenium species in water is an analytical challenge. Solid-phase extraction has been used as a separation and/or preconcentration technique prior to the determination of selenium species due to the need for accurate measurements for Se species in water at extremely low levels. The present paper provides a critical review of the published methods for inorganic selenium speciation in water samples using solid phase extraction as a preconcentration procedure. On the basis of more than 75 references, the different speciation strategies used for this task have been highlighted and classified. The solid-phase extraction sorbents and the performance and analytical characteristics of the developed methods for Se speciation are also discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Use of field-applied quality control samples to monitor performance of a Goulden large-sample extractor/GC-MS method for pesticides in water

    Science.gov (United States)

    Foreman, W.T.; Gates, Paul M.; Foster, G.D.; Rinella, F.A.; McKenzie, S.W.

    2000-01-01

    Since 1985, the Goulden large-sample extractor (GLSE) has been used to isolate a broad array of trace-organic contaminants from large volumes of water. In this study, field-applied quality control measures, including matrix and surrogate spikes and blanks, were used to monitor method performance from GLSE extraction through GC-MS analysis. The method was applied to the determination of multiple classes of pesticides isolated from 4- to 112-L filtered surface-water samples. Average recoveries of six surrogate compounds ranged from 84 ?? 18% for [2H10]diazinon to 15 ?? 13% for 4,4'-[2H8]DDT, the low recoveries for which were largely a result of unmonitored breakdown of this surrogate by the GC injection system. Field-matrix-spike samples were prepared by fortifying 10-L, 35-L, and 110-L filtered surface-water samples with 68 pesticides to amended concentrations of 11- to 50-ng/L each. Recoveries ranged from not detected to greater than 100%. Variability in pesticide recoveries from triplicate 10-L water samples collected at one site averaged 5.7% relative standard deviation and did not exceed 19%.Since 1985, the Goulden large-sample extractor (GLSE) has been used to isolate a broad array of trace-organic contaminants from large volumes of water. In this study, field-applied quality control measures, including matrix and surrogate spikes and blanks, were used to monitor method performance from GLSE extraction through GC-MS analysis. The method was applied to the determination of multiple classes of pesticides isolated from 4- to 112-L filtered surface-water samples. Average recoveries of six surrogate compounds ranged from 84 ?? 18% for [2H10]diazinon to 15 ?? 13% for 4,4???-[2H8]DDT, the low recoveries for which were largely a result of unmonitored breakdown of this surrogate by the GC injection system. Field-matrix-spike samples were prepared by fortifying 10-L, 35-L, and 110-L filtered surface-water samples with 68 pesticides to amended concentrations of 11- to 50

  8. Correlation of lithium levels between drinking water obtained from different sources and scalp hair samples of adult male subjects.

    Science.gov (United States)

    Baloch, Shahnawaz; Kazi, Tasneem Gul; Afridi, Hassan Imran; Baig, Jameel Ahmed; Talpur, Farah Naz; Arain, Muhammad Balal

    2017-10-01

    There is some evidence that natural levels of lithium (Li) in drinking water may have a protective effect on neurological health. In present study, we evaluate the Li levels in drinking water of different origin and bottled mineral water. To evaluate the association between lithium levels in drinking water with human health, the scalp hair samples of male subjects (25-45 years) consumed drinking water obtained from ground water (GW), municipal treated water (MTW) and bottled mineral water (BMW) from rural and urban areas of Sindh, Pakistan were selected. The water samples were pre-concentrated five to tenfold at 60 °C using temperature-controlled electric hot plate. While scalp hair samples were oxidized by acid in a microwave oven, prior to determined by flame atomic absorption spectrometry. The Li content in different types of drinking water, GW, MTW and BMW was found in the range of 5.12-22.6, 4.2-16.7 and 0.0-16.3 µg/L, respectively. It was observed that Li concentration in the scalp hair samples of adult males consuming ground water was found to be higher, ranged as 292-393 μg/kg, than those who are drinking municipal treated and bottle mineral water (212-268 and 145-208 μg/kg), respectively.

  9. Trace analysis of iron in environmental water and snow samples from Poland

    International Nuclear Information System (INIS)

    Golimowski, J.

    1989-01-01

    A voltammetric method for the determination of iron at detection limit of 4 μg/l is described, using the catalytic current of the reduction of the Fe(III)-triethanolamine (TEA) complex in the presence of bromate ions. The determination was performed at a mercury hanging drop electrode without preconcentration, using the TEA alkaline solution as a supporting electrolyte and the differential pulse technique. A peak current for the Fe-(III)-TEA catalytic reduction was observed at a potential of -1.0 V (Ag/AgCl saturated electrode). The influence of TEA, BrO 3 and NaOH concentrations on the peak height was studied. It was found that a 100-fold excess of Mn, a 50-fold excess of Cr(VI) and Zn did not interfere in the determination. This method was applied to the determination of iron in water, snow and waste water samples

  10. Detection and spatial mapping of mercury contamination in water samples using a smart-phone.

    Science.gov (United States)

    Wei, Qingshan; Nagi, Richie; Sadeghi, Kayvon; Feng, Steve; Yan, Eddie; Ki, So Jung; Caire, Romain; Tseng, Derek; Ozcan, Aydogan

    2014-02-25

    Detection of environmental contamination such as trace-level toxic heavy metal ions mostly relies on bulky and costly analytical instruments. However, a considerable global need exists for portable, rapid, specific, sensitive, and cost-effective detection techniques that can be used in resource-limited and field settings. Here we introduce a smart-phone-based hand-held platform that allows the quantification of mercury(II) ions in water samples with parts per billion (ppb) level of sensitivity. For this task, we created an integrated opto-mechanical attachment to the built-in camera module of a smart-phone to digitally quantify mercury concentration using a plasmonic gold nanoparticle (Au NP) and aptamer based colorimetric transmission assay that is implemented in disposable test tubes. With this smart-phone attachment that weighs cellphones could be rather useful for distributed sensing, tracking, and sharing of water contamination information as a function of both space and time.

  11. Evaluation of lyophilization for the preconcentration of natural water samples prior to neutron activation analysis

    International Nuclear Information System (INIS)

    Harrison, S.H.; LaFleur, P.D.; Zoller, W.H.

    1975-01-01

    Water is preconcentrated by freeze drying using a method which virtually eliminates sample contamination and trace element losses. To test the possibility of losses of volatile elements during the drying process, known quantities of radioactive tracers for 21 elements were added to water, the solutions freeze dried, and the tracer residues counted. The results confirm that at least 95 percent of all but the most volatile elements studied (Hg and I) were retained in the residue. The problem of transferring quantitatively the dry residue from the freeze drying container to an irradiation container was eliminated by designing a freeze drying container that would also serve as an irradiation and counting container. (U.S.)

  12. An alternative method for float-sink analysis of fine coal samples using water fluidization

    Energy Technology Data Exchange (ETDEWEB)

    A.M. Callen; S.J. Pratten; B.D. Belcher; N. Lambert; K.P. Galvin [University of Newcastle, Callaghan, NSW (Australia). School of Engineering

    2002-12-01

    The study reported is concerned with the development of a new method, based on water fluidization, for obtaining washability information for -4 +0.045 mm coal samples, with a view to providing a rapid, accurate, and safe alternative to the current laboratory method of float-sink testing. Previously, Galvin and Pratten have reported the technique of utilizing the density segregation effect of a narrow size range of particles in a fluidized bed to determine washability data. Here, the evaluation of the new method by determining the yield-ash data of a number of different Australian coals has demonstrated the robustness and accuracy of the water fluidization method. 7 refs., 9 figs., 1 app.

  13. Data Validation Package - April and July 2015 Groundwater and Surface Water Sampling at the Gunnison, Colorado, Processing Site

    Energy Technology Data Exchange (ETDEWEB)

    Linard, Joshua [Dept. of Energy (DOE), Washington, DC (United States). Office of Legacy Management; Campbell, Sam [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States)

    2016-02-01

    This event included annual sampling of groundwater and surface water locations at the Gunnison, Colorado, Processing Site. Sampling and analyses were conducted as specified in Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites. Samples were collected from 28 monitoring wells, three domestic wells, and six surface locations in April at the processing site as specified in the 2010 Ground Water Compliance Action Plan for the Gunnison, Colorado, Processing Site. Domestic wells 0476 and 0477 were sampled in July because the homes were unoccupied in April, and the wells were not in use. Duplicate samples were collected from locations 0113, 0248, and 0477. One equipment blank was collected during this sampling event. Water levels were measured at all monitoring wells that were sampled. No issues were identified during the data validation process that requires additional action or follow-up.

  14. Analysis of {sup 210}Pb in water samples with plastic scintillation resins

    Energy Technology Data Exchange (ETDEWEB)

    Lluch, E.; Barrera, J. [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain); Tarancón, A., E-mail: alex.tarancon@ub.edu [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain); Bagán, H. [Department of Pure and Applied Biochemistry, Lund University, Getingevägen 60, Hus II, 22100 SE, Lund (Sweden); García, J.F. [Department of Analytical Chemistry, University of Barcelona, Martí i Franqués, 1-11, E-08028, Barcelona (Spain)

    2016-10-12

    {sup 210}Pb is a radioactive lead isotope present in the environment as member of the {sup 238}U decay chain. Since it is a relatively long-lived radionuclide (T{sub 1/2} = 22.2 years), its analysis is of interest in radiation protection and the geochronology of sediments and artwork. Here, we present a method for analysing {sup 210}Pb using plastic scintillation resins (PSresins) packaged in solid-phase extraction columns (SPE cartridge). The advantages of this method are its selectivity, the low limit of detection, as well as reductions in the amount of time and reagents required for analysis and the quantity of waste generated. The PSresins used in this study were composed of a selective extractant (4′,4″(5″)-Di-tert-butyldicyclohexano-18-crown-6 in 1-octanol) covering the surface of plastic scintillation microspheres. Once the amount of extractant (1:1/4) and medium of separation (2 M HNO{sub 3}) were optimised, PSresins in SPE cartridges were calibrated with a standard solution of {sup 210}Pb. {sup 210}Pb could be fully separated from its daughters, {sup 210}Bi and {sup 210}Po, with a recovery value of 91(3)% and detection efficiency of 44(3)%. Three spiked water samples (one underground and two river water samples) were analysed in triplicates with deviations lower than 10%, demonstrating the validity of the PS resin method for {sup 210}Pb analysis. - Highlights: • A plastic scintillation resin for selective analysis of {sup 210}Pb has been developed. • A commercial SPE cartridge has been use for separation and scintillation counting. • {sup 210}Pb separation from {sup 210}Bi and {sup 210}Po is achieved with a 91(3)% of recovery. • The method is valid for analysis of {sup 210}Pb in river water samples.

  15. Determination of 222Rn in water samples from wells and springs in Tokyo by a modified integral counting method

    International Nuclear Information System (INIS)

    Homma, Y.; Murase, Y.; Handa, K.; Murakami, I.

    1997-01-01

    222 Rn in 2L-water samples was extracted with 30 mL toluene, and 21 mL of the toluene solution was transferred into a liquid scintillation vial, in which PPO - 2,5-diphenyloxazole was placed in advance. The total activity of 222 Rn in the water sample was calculated based on the Ostwald's coefficient of solubilities of 222 Rn in toluene and water at the temperature of the sample water and the volume of water and toluene. About 40% of 222 Rn dissolved in 2L-water sample can be collected. After allowing to stand for 3.5 h, the equilibrium mixture of 222 Rn and its daughters was measured with an Aloka liquid scintillation spectrometer using a modified integral counting method which extrapolates the integral counting curve not to the zero pulse-height, but to the zero detection threshold, an average energy required to produce a measurable pulse, of the liquid scintillation spectrometer. The general method which agitates water sample (usually about 10 mL) with a liquid scintillation cocktail is practical when the activity of 222 Rn is high. By adding 10 mL of water sample, however, it is possible also to add variable amounts of quencher. In some cases water sample is preserved with nitric acid. The slope of the integral counting rate curve increases as quench level of the sample increases. Therefore, it is clear that the modified integral counting method gives more accurate 222 Rn concentrations for water samples of strong quench than the conventional integral counting method. 222 Rn sample of 0.2 Bq/L can be determined within an overall uncertainty of 3.1%

  16. A certified reference material for radionuclides in the water sample from Irish Sea (IAEA-443)

    DEFF Research Database (Denmark)

    Pham, M.K.; Betti, M.; Povinec, P.P.

    2011-01-01

    values on massic activities with 95% confidence intervals are given for four radionuclides (230Th, 232Th, 239Pu and 240Pu). Results for less frequently reported radionuclides (99Tc, 228Th, 237Np and 241Pu) are also reported. The CRM can be used for quality assurance/quality control of the analysis...... of radionuclides in water samples, for the development and validation of analytical methods and for training purposes. The material is available in 5 L units from IAEA (http://nucleus.iaea.org/rpst/index.htm)....

  17. Procedures for Handling and Chemical Analysis of Sediment and Water Samples,

    Science.gov (United States)

    1981-05-01

    control program, beginning with sample collection. The three chemical tests that are described are: a. A short-term water leaching test (the standard...demand P, G 300 ml-2 Z 4 0 C 6 hr Chemical oxygen demand P, (3 200 ml H2S04 to pH < 2 7 days 4 °C PCB’s ( 2 Z 4°c Orranochlorine pesti- cides C I Z 40 C...the purpose of the study as discussed in Section 1. The elutriate test is a short-term, sediment- leaching procedure. It consists of agitating a known

  18. Predictors of narghile (water-pipe) smoking in a sample of American Arab Yemeni adolescents.

    Science.gov (United States)

    Baker, Omar G; Rice, Virginia

    2008-01-01

    To explore the predictors of water-pipe smoking among American Arab Yemeni adolescents, a descriptive correlational design was used, and regression models representing the proposed relationships in the study were tested from a convenience sample of 297 adolescents who attended a teen health clinic and two high schools. The participants completed five measures. Fourteen hypotheses were tested. Experimentation with tobacco was found to be significant in predicting narghile smoking. Tobacco use prevention and cessation interventions for this population can be focused on targeting the family and peer units, from which their identity is likely derived.

  19. Cloud point extraction, preconcentration and spectrophotometric determination of nickel in water samples using dimethylglyoxime

    Directory of Open Access Journals (Sweden)

    Morteza Bahram

    2013-01-01

    Full Text Available A new and simple method for the preconcentration and spectrophotometric determination of trace amounts of nickel was developed by cloud point extraction (CPE. In the proposed work, dimethylglyoxime (DMG was used as the chelating agent and Triton X-114 was selected as a non-ionic surfactant for CPE. The parameters affecting the cloud point extraction including the pH of sample solution, concentration of the chelating agent and surfactant, equilibration temperature and time were optimized. Under the optimum conditions, the calibration graph was linear in the range of 10-150 ng mL-1 with a detection limit of 4 ng mL-1. The relative standard deviation for 9 replicates of 100 ng mL-1 Ni(II was 1.04%. The interference effect of some anions and cations was studied. The method was applied to the determination of Ni(II in water samples with satisfactory results.

  20. Removal of Pb ion from water samples using red mud (bauxite ore processing waste

    Directory of Open Access Journals (Sweden)

    Ghorbani A.

    2014-07-01

    Full Text Available This work presented the use of red mud (bauxite ore processing waste in removal of lead ions in water samples. For this 0.1 g of red mud has been used as adsorbent which suspended in 10 ml of lead solution with the concentration of 50 mg l-1 for about 1 h. After that the lead concentration in the samples taken from the red mud treated lead solution measured with atomic absorption spectroscopy (AAS. The effect of some parameter which is important in adsorption of lead on red mud such as suitable adsorbent dosage, pH and contact time of solution and adsorbent was investigated. The result shows that red mud as solid waste and low-cost adsorbent can be successfully used for the removal of lead ion from aqueous solution.