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Sample records for processing contaminated nak

  1. Decontamination and decommissioning plan for processing contaminated NaK at the INEL

    SciTech Connect

    LaRue, D.M.; Dolenc, M.R.

    1986-09-01

    This decontamination and decommissioning (D&D) plan describes the work elements and project management plan for processing four containers of contaminated sodium/potassium (NaK) and returning the Army Reentry Vehicle Facility Site (ARVFS) to a reusable condition. The document reflects the management plan for this project before finalizing the conceptual design and preliminary prototype tests of the reaction kinetics. As a result, the safety, environmental, and accident analyses are addressed as preliminary assessments before completion at a later date. ARVFS contains an earth-covered bunker, a cylindrical test pit and metal shed, and a cable trench connecting the two items. The bunker currently stores the four containers of NaK from the meltdown of the EBR-1 Mark II core. The D&D project addressed in this plan involves processing the contaminated NaK and returning the ARVFS to potential reuse after cleanup.

  2. Decontamination and decommissioning plan for processing contaminated NaK at the INEL

    SciTech Connect

    LaRue, D.M.; Dolenc, M.R.

    1986-09-01

    This decontamination and decommissioning (D D) plan describes the work elements and project management plan for processing four containers of contaminated sodium/potassium (NaK) and returning the Army Reentry Vehicle Facility Site (ARVFS) to a reusable condition. The document reflects the management plan for this project before finalizing the conceptual design and preliminary prototype tests of the reaction kinetics. As a result, the safety, environmental, and accident analyses are addressed as preliminary assessments before completion at a later date. ARVFS contains an earth-covered bunker, a cylindrical test pit and metal shed, and a cable trench connecting the two items. The bunker currently stores the four containers of NaK from the meltdown of the EBR-1 Mark II core. The D D project addressed in this plan involves processing the contaminated NaK and returning the ARVFS to potential reuse after cleanup.

  3. The effects of Na/K additives and flyash on NO reduction in a SNCR process.

    PubMed

    Hao, Jiangtao; Yu, Wei; Lu, Ping; Zhang, Yufei; Zhu, Xiuming

    2015-03-01

    An experimental study of Na/K additives and flyash on NO reduction during the selective non-catalytic reduction (SNCR) process were carried out in an entrained flow reactor (EFR). The effects of reaction temperature (Tr), water vapor, Na/K additives (NaCl, KCl, Na2CO3) and flyash characteristics on NO reduction were analyzed. The results indicated that NO removal efficiency shows a pattern of increasing first and decreasing later with the increase of the temperature at Tr=850-1150°C. Water vapor can improve the performance of NO reduction, and the NO reduction of 70.5% was obtained while the flue gas containing 4% water vapor at 950°C. Na/K additives have a significant promoting effect on NO reduction and widen the SNCR temperature window, the promoting effect of the test additives is ordered as Na2CO3>KCl>NaCl. NO removal efficiency with 125ppm Na2CO3 and 4% water vapor can reach up to 84.9% at the optimal reaction temperature. The additive concentration has no significant effects on NO reduction while its concentration is above 50ppm. Addition of circulating fluidized combustion (CFB) flyash deteriorates NO reduction significantly. However, CFB flyash and Na/K additives will get a coupling effect on NO reduction during the SNCR process, and the best NO reduction can reach 72.3% while feeding Na2CO3-impregnated CFB flyash at 125ppm Na2CO3 and Tr=950°C. PMID:25532766

  4. Contaminated nickel scrap processing

    SciTech Connect

    Compere, A.L.; Griffith, W.L.; Hayden, H.W.; Johnson, J.S. Jr.; Wilson, D.F.

    1994-12-01

    The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include {sup 234}Th, {sup 234}Pa, {sup 137}Cs, {sup 239}Pu (trace), {sup 60}Co, U, {sup 99}Tc, and {sup 237}Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs.

  5. Treatment of EBR-I NaK mixed waste at Argonne National Laboratory and subsequent land disposal at the Idaho National Engineering and Environmental Laboratory.

    SciTech Connect

    Herrmann, S. D.; Buzzell, J. A.; Holzemer, M. J.

    1998-02-03

    Sodium/potassium (NaK) liquid metal coolant, contaminated with fission products from the core meltdown of Experimental Breeder Reactor I (EBR-I) and classified as a mixed waste, has been deactivated and converted to a contact-handled, low-level waste at Argonne's Sodium Component Maintenance Shop and land disposed at the Radioactive Waste Management Complex. Treatment of the EBR-I NaK involved converting the sodium and potassium to its respective hydroxide via reaction with air and water, followed by conversion to its respective carbonate via reaction with carbon dioxide. The resultant aqueous carbonate solution was solidified in 55-gallon drums. Challenges in the NaK treatment involved processing a mixed waste which was incompletely characterized and difficult to handle. The NaK was highly radioactive, i.e. up to 4.5 R/hr on contact with the mixed waste drums. In addition, the potential existed for plutonium and toxic characteristic metals to be present in the NaK, resultant from the location of the partial core meltdown of EBR-I in 1955. Moreover, the NaK was susceptible to degradation after more than 40 years of storage in unmonitored conditions. Such degradation raised the possibility of energetic exothermic reactions between the liquid NaK and its crust, which could have consisted of potassium superoxide as well as hydrated sodium/potassium hydroxides.

  6. A Conserved Hydrophobic Tetrad near the C Terminus of the Secretory Na+-K+-2Cl- Cotransporter (NKCC1) Is Required for Its Correct Intracellular Processing*

    PubMed Central

    Nezu, Akihiro; Parvin, Most. Nahid; Turner, R. James

    2009-01-01

    Little is known about the intracellular folding and trafficking of integral membrane proteins. Here we identify a hydrophobic amino acid tetrad (ILLV) close to the C terminus of the secretory Na+-K+-2Cl- cotransporter (NKCC1) that is important for the proper intracellular processing of this protein. This tetrad appears in a C-terminal sequence pattern that is conserved across species in a number of members of the NKCC1 gene family (slc12) of electroneutral salt transporters. We studied the effects of various mutations of these amino acids on NKCC1 transiently transfected into HEK-293 cells. Our results show that mutation of two of these residues to alanine leads to a >50% reduction in expression and complex glycosylation levels and that multiple mutations to alanine have cumulative effects. By contrast, scrambling of these amino acids, or mutation of other nearby conserved C-terminal residues, has little effect on these parameters. Mutation of ILLV to AAAA reduces complex glycosylation of NKCC1 by ∼90% and results in a protein that does not form stable dimers and is retained in the endoplasmic reticulum in a highly aggregated state. Our results are consistent with the hypothesis that mutation of the hydrophobic tetrad ILLV to AAAA leads to the ab initio misfolding and concomitant aggregation of this NKCC1 mutant, resulting in its retention in the endoplasmic reticulum. PMID:19129177

  7. Cleaning residual NaK in the fast flux test facility fuel storage cooling system

    SciTech Connect

    Burke, T.M.; Church, W.R.; Hodgson, K.M.

    2008-01-15

    The Fast Flux Test Facility (FFTF), located on the U.S. Department of Energy's Hanford Reservation, is a liquid metal-cooled test reactor. The FFTF was constructed to support the U.S. Liquid Metal Fast Breeder Reactor Program. The bulk of the alkali metal (sodium and NaK) has been drained and will be stored onsite prior to final disposition. Residual NaK needed to be removed from the pipes, pumps, heat exchangers, tanks, and vessels in the Fuel Storage Facility (FSF) cooling system. The cooling system was drained in 2004 leaving residual NaK in the pipes and equipment. The estimated residual NaK volume was 76 liters in the storage tank, 1.9 liters in the expansion tank, and 19-39 liters in the heat transfer loop. The residual NaK volume in the remainder of the system was expected to be very small, consisting of films, droplets, and very small pools. The NaK in the FSF Cooling System was not radiologically contaminated. The portions of the cooling system to be cleaned were divided into four groups: 1. The storage tank, filter, pump, and associated piping; 2. The heat exchanger, expansion tank, and associated piping; 3. Argon supply piping; 4. In-vessel heat transfer loop. The cleaning was contracted to Creative Engineers, Inc. (CEI) and they used their superheated steam process to clean the cooling system. It has been concluded that during the modification activities (prior to CEI coming onsite) to prepare the NaK Cooling System for cleaning, tank T-914 was pressurized relative to the In-Vessel NaK Cooler and NaK was pushed from the tank back into the Cooler and that on November 6, 2005, when the gas purge through the In-Vessel NaK Cooler was increased from 141.6 slm to 283.2 slm, NaK was forced from the In-Vessel NaK Cooler and it contacted water in the vent line and/or scrubber. The gases from the reaction then traveled back through the vent line coating the internal surface of the vent line with NaK and NaK reaction products. The hot gases also exited the

  8. Bacterial adherence and contamination during radiographic processing.

    PubMed

    Bachman, C E; White, J M; Goodis, H E; Rosenquist, J W

    1990-11-01

    Oral fluids are potential contaminants of radiographic processors. This investigation measured bacterial contamination in a radiographic processing room during times of high and low clinical activity and processing effects on five types of microorganisms. Cultures in the clinical setting, during high and low activity, were taken by brain-heart infusion agar plates placed near automatic processors. Site samples were taken of entrance, developer, fixer, water, and exit surfaces. Measurements of processing effects were accomplished by intentional contamination of films run in series through an automatic processor. Site samples were again taken of the processor. In the clinical setting colony-forming units increased with activity. Radiographic processing after intentional contamination decreased colony-forming units on films, but they increased for all processing solutions. Bacteria on radiographic film survived processing. Although processing procedures significantly reduce the number of bacteria on films, the potential for contamination and cross-contamination remains. PMID:2122350

  9. Contamination detection NDE for cleaning process inspection

    NASA Technical Reports Server (NTRS)

    Marinelli, W. J.; Dicristina, V.; Sonnenfroh, D.; Blair, D.

    1995-01-01

    In the joining of multilayer materials, and in welding, the cleanliness of the joining surface may play a large role in the quality of the resulting bond. No non-intrusive techniques are currently available for the rapid measurement of contamination on large or irregularly shaped structures prior to the joining process. An innovative technique for the measurement of contaminant levels in these structures using laser based imaging is presented. The approach uses an ultraviolet excimer laser to illuminate large and/or irregular surface areas. The UV light induces fluorescence and is scattered from the contaminants. The illuminated area is viewed by an image-intensified CCD (charge coupled device) camera interfaced to a PC-based computer. The camera measures the fluorescence and/or scattering from the contaminants for comparison with established standards. Single shot measurements of contamination levels are possible. Hence, the technique may be used for on-line NDE testing during manufacturing processes.

  10. Catalyst regeneration process including metal contaminants removal

    DOEpatents

    Ganguli, Partha S.

    1984-01-01

    Spent catalysts removed from a catalytic hydrogenation process for hydrocarbon feedstocks, and containing undesired metals contaminants deposits, are regenerated. Following solvent washing to remove process oils, the catalyst is treated either with chemicals which form sulfate or oxysulfate compounds with the metals contaminants, or with acids which remove the metal contaminants, such as 5-50 W % sulfuric acid in aqueous solution and 0-10 W % ammonium ion solutions to substantially remove the metals deposits. The acid treating occurs within the temperature range of 60.degree.-250.degree. F. for 5-120 minutes at substantially atmospheric pressure. Carbon deposits are removed from the treated catalyst by carbon burnoff at 800.degree.-900.degree. F. temperature, using 1-6 V % oxygen in an inert gas mixture, after which the regenerated catalyst can be effectively reused in the catalytic process.

  11. Cleaning process for contaminated superalloy powders

    NASA Technical Reports Server (NTRS)

    Anglin, A. E.

    1978-01-01

    A cleaning process for removing interstitial contaminants from superalloy powders after wet grinding is described. Typical analyses of oxygen, carbon, nitrogen, and hydrogen in ball-milled WAZ-20 superalloy samples after hydrogen plus vacuum cleaning are presented. The hydrogen cleaning step involves heating retorts containing superalloy powder twice under flowing hydrogen with a 24-hour hold at each temperature. The vacuum step involves heating cold-pressed billets two hours at an elevated temperature at a pressure of 10 microPa. It is suggested that the hydrogen plus vacuum cleaning procedure can be applied to superalloys contaminated by other substances in other industrial processes.

  12. Catalytic extraction processing of contaminated scrap metal

    SciTech Connect

    Griffin, T.P.; Johnston, J.E.

    1994-12-31

    The contract was conceived to establish the commercial capability of Catalytic Extraction Processing (CEP) to treat contaminated scrap metal in the DOE inventory. In so doing, Molten Metal Technology, Inc. (MMT), pursued the following objectives: demonstration of the recycling of ferrous and non-ferrous metals--to establish that radioactively contaminated scrap metal can be converted to high-grade, ferrous and non-ferrous alloys which can be reused by DOE or reintroduced into commerce; immobilize radionuclides--that CEP will concentrate the radionuclides in a dense vitreous phase, minimize secondary waste generation and stabilize and reduce waste volume; destroy hazardous organics--that CEP will convert hazardous organics to valuable industrial gases, which can be used as feed gases for chemical synthesis or as an energy source; recovery volatile heavy metals--that CEP`s off-gas treatment system will capture volatile heavy metals, such as mercury and lead; and establish that CEP is economical for processing contaminated scrap metal in the DOE inventory--that CEP is a more cost-effective and, complete treatment and recycling technology than competing technologies for processing contaminated scrap. The process and its performance are described.

  13. Particle contamination formation in magnetron sputtering processes

    SciTech Connect

    Selwyn, G.S.; Sequeda, F.; Huang, C.

    1997-07-01

    Defects caused by particulate contamination are an important concern in the fabrication of thin film products. Often, magnetron sputtering processes are used for this purpose. Particle contamination generated during thin film processing can be detected using laser light scattering, a powerful diagnostic technique which provides real-time, {ital in situ} imaging of particles {gt}0.3 {mu}m on the target, substrate, or in the plasma. Using this technique, we demonstrate that the mechanisms for particle generation, transport, and trapping during magnetron sputter deposition are different from the mechanisms reported in previously studied plasma etch processes, due to the inherent spatial nonuniformity of magnetically enhanced plasmas. During magnetron sputter deposition, one source of particle contamination is linked to portions of the sputtering target surface exposed to weaker plasma density. There, film redeposition induces filament or nodule growth. Sputter removal of these features is inhibited by the dependence of sputter yield on angle of incidence. These features enhance trapping of plasma particles, which then increases filament growth. Eventually the growths effectively {open_quotes}short-circuit{close_quotes} the sheath, causing high currents to flow through these features. This, in turn, causes mechanical failure of the growth resulting in fracture and ejection of the target contaminants into the plasma and onto the substrate. Evidence of this effect has been observed in semiconductor fabrication and storage disk manufacturing. Discovery of this mechanism in both technologies suggests it may be universal to many sputter processes. {copyright} {ital 1997 American Vacuum Society.}

  14. PROCESS OF DECONTAMINATING MATERIAL CONTAMINATED WITH RADIOACTIVITY

    DOEpatents

    Overholt, D.C.; Peterson, M.D.; Acken, M.F.

    1958-09-16

    A process is described for decontaminating metallic objects, such as stainless steel equipment, which consists in contacting such objects with nltric acid in a concentration of 35 to 60% to remove the major portion of the contamination; and thereafter contacting the partially decontaminated object with a second solution containing up to 20% of alkali metal hydroxide and up to 20% sodium tartrate to remove the remaining radioactive contaminats.

  15. Catalytic extraction processing of contaminated scrap metal

    SciTech Connect

    Griffin, T.P.; Johnston, J.E.; Payea, B.M.

    1995-10-01

    The U.S. Department of Energy issued a Planned Research and Development Announcement (PRDA) in 1993, with the objective of identifying unique technologies which could be applied to the most hazardous waste streams at DOE sites. The combination of radioactive contamination with additional contamination by hazardous constituents such as those identified by the Resource Conservation and Recovery Act (RCRA) pose an especially challenging problem. Traditional remediation technologies are increasingly becoming less acceptable to stakeholders and regulators because of the risks they pose to public health and safety. Desirable recycling technologies were described by the DOE as: (1) easily installed, operated, and maintained; (2) exhibiting superior environmental performance; (3) protective of worker and public health and safety; (4) readily acceptable to a wide spectrum of evaluators; and (5) economically feasible. Molten Metal Technology, Inc. (MMT) was awarded a contract as a result of the PRDA initiative to demonstrate the applicability of Catalytic Extraction Processing (CEP), MMT`s proprietary elemental recycling technology, to DOE`s inventory of low level mixed waste. This includes DOE`s inventory of radioactively- and RCRA-contaminated scrap metal and other waste forms expected to be generated by the decontamination and decommissioning (D&D) of DOE sites.

  16. Contamination control in hybrid microelectronic modules. Identification of critical process and contaminants, part 1

    NASA Technical Reports Server (NTRS)

    Himmel, R. P.

    1975-01-01

    Hybrid processes, handling procedures, and materials were examined to identify the critical process steps in which contamination is most likely to occur, to identify the particular contaminants associated with these critical steps, and to propose method for the control of these contaminants.

  17. Process Upsets Involving Trace Contaminant Control Systems

    NASA Technical Reports Server (NTRS)

    Graf, John C.; Perry, Jay; Wright, John; Bahr, Jim

    2000-01-01

    Paradoxically, trace contaminant control systems that suffer unexpected upsets and malfunctions can release hazardous gaseous contaminants into a spacecraft cabin atmosphere causing potentially serious toxicological problems. Trace contaminant control systems designed for spaceflight typically employ a combination of adsorption beds and catalytic oxidation reactors to remove organic and inorganic trace contaminants from the cabin atmosphere. Interestingly, the same design features and attributes which make these systems so effective for purifying a spacecraft's atmosphere can also make them susceptible to system upsets. Cabin conditions can be contributing causes of phenomena such as adsorbent "rollover" and catalyst poisoning can alter a systems performance and in some in stances release contamination into the cabin. Evidence of these phenomena has been observed both in flight and during ground-based tests. The following discussion describes specific instances of system upsets found in trace contaminant control systems, groups these specific upsets into general hazard classifications, and recommends ways to minimize these hazards.

  18. Contamination Control in Hybrid Microelectronic Modules. Part 1: Identification of Critical Process and Contaminants

    NASA Technical Reports Server (NTRS)

    Himmel, R. P.

    1975-01-01

    Various hybrid processing steps, handling procedures, and materials are examined in an attempt to identify sources of contamination and to propose methods for the control of these contaminants. It is found that package sealing, assembly, and rework are especially susceptible to contamination. Moisture and loose particles are identified as the worst contaminants. The points at which contaminants are most likely to enter the hybrid package are also identified, and both general and specific methods for their detection and control are developed. In general, the most effective controls for contaminants are: clean working areas, visual inspection at each step of the process, and effective cleaning at critical process steps. Specific methods suggested include the detection of loose particles by a precap visual inspection, by preseal and post-seal electrical testing, and by a particle impact noise test. Moisture is best controlled by sealing all packages in a clean, dry, inert atmosphere after a thorough bake-out of all parts.

  19. {open_quote}Lasagna{close_quote} process treats contaminants

    SciTech Connect

    Drennan, D.

    1994-09-01

    This paper describes an integrated in-situ remedial technology for organic or inorganic contaminants in dense soils termed the Lasagna Process. The process, so named for its layers, forces contaminants out of microscopic pores in clay and silt soil regions so they do not leach into groundwater. It introduces in-situ treatment zones in the contaminated area so the waste will not have to be brought to the surface and treats the material within the newly created zones.

  20. Collisional Transfer of Population and Orientation in NaK

    NASA Astrophysics Data System (ADS)

    Wolfe, C. M.; Ashman, S.; Huennekens, J.; Beser, B.; Bai, J.; Lyyra, A. M.

    2010-03-01

    We report current work to study transfer of population and orientation in collisions of NaK molecules with argon and potassium atoms using polarization labeling (PL) and laser- induced fluorescence (LIF) spectroscopy. In the PL experiment, a circularly polarized pump laser excites a specific NaK A^1&+circ;(v'=16, J') <- X^1&+circ;(v''=0, J'±1) transition, creating an orientation (non-uniform MJ' level distribution) in both levels. The linearly polarized probe laser is scanned over various 3^1π(v, J'±1) <- A^1&+circ;(v'=16, J') transitions. The probe laser passes through a crossed linear polarizer before detection, and signal is recorded if the probe laser polarization has been modified by the vapor (which occurs when it comes into resonance with an oriented level). Using both spectroscopic methods, analysis of weak collisional satellite lines adjacent to these directly populated lines, as a function of argon buffer gas pressure and cell temperature, allows us to discern separately the effects collisions with argon atoms and potassium atoms have on the population and orientation of the molecule. In addition, code has been written which provides a theoretical analysis of the process, through a solution of the density matrix equations of motion for the system.

  1. ELECTROCHEMICAL PROCESSES FOR IN-SITU TREATMENT OF CONTAMINATED SOILS

    EPA Science Inventory

    This project will study electrochemical processes for the in situ treatment of soils contaminated by mixed wastes, i.e., organic and inorganic. Soil samples collected from selected DOE waste sites will be characterized for specific organic and metal contaminants and hydraulic per...

  2. Innovative technology for contamination control in plasma processing

    SciTech Connect

    Selwyn, G.S.

    1994-10-01

    The causes and contributing factors to wafer contamination during plasma processing are discussed in the context of future technologies for controlling particle contamination by tool and process design and by the development of wafer dry cleaning technology. The importance of these developments is linked with the history of technological innovation and with the continuing evolution of the cleanroom from a highly developed facility for reducing ambient particle levels to an integrated, synergistic approach involving facilities and tooling for impeding the formation and transport of particles while also actively removing particles from sensitive surfaces. The methods, strategy and requirements for innovation in contamination control for plasma processing is discussed from a diachronic viewpoint.

  3. Parallel Processing of a Groundwater Contaminant Code

    SciTech Connect

    Arnett, Ronald Chester; Greenwade, Lance Eric

    2000-05-01

    The U. S. Department of Energy’s Idaho National Engineering and Environmental Laboratory (INEEL) is conducting a field test of experimental enhanced bioremediation of trichoroethylene (TCE) contaminated groundwater. TCE is a chlorinated organic substance that was used as a solvent in the early years of the INEEL and disposed in some cases to the aquifer. There is an effort underway to enhance the natural bioremediation of TCE by adding a non-toxic substance that serves as a feed material for the bacteria that can biologically degrade the TCE.

  4. 9. VIEW OF CLOSED CARRIER LINES FOR MOVING CONTAMINATED PROCESS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF CLOSED CARRIER LINES FOR MOVING CONTAMINATED PROCESS FILTERS AND TRANSPORTING SOLID AND LIQUID MATERIAL SAMPLES. (9/10/96) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

  5. Processes of contaminant accumulation in an Arctic beluga whale population

    SciTech Connect

    Hickie, B.E.; Muir, D.; Kingsley, M.

    1995-12-31

    As long-lived top predators in marine food chains, marine mammals accumulate high levels of persistent organic contaminants. While arctic marine mammal contaminant concentrations are lower than those from temperate regions, levels are sufficiently high to be a health concern to people who rely on marine mammals as food. Monitoring programs developed to address this problem and to define spatial and temporal trends often are difficult to interpret since tissue contaminant concentrations vary with species, age, sex, reproductive effort, and condition (ie blubber thickness). It can be difficult to relate contaminant concentrations in other environmental compartments to those in marine mammals since their residues reflect exposure over their entire life, often 20 to 30 years. Contaminant accumulation models for marine mammals enable us to better understand the importance of, and interaction between, factors affecting contaminant accumulation, and can provide a dynamic framework for interpreting contaminant monitoring data. The authors developed two models for the beluga whale (Delphinapterus leucas): one provides a detailed view of processes at the individual level, the other examines population-based processes. The models quantify uptake, release and disposition of organic contaminants over their entire lifespan by incorporating all aspects of life-history. These models are used together to examine impact of a variety of factors on patterns and variability of PCBs found in the West Greenland beluga population (sample size: 696, 729). Factors examined include: energetics, growth, birth rate, lactation, contaminant assimilation and clearance rates, and dietary contaminant concentrations. Results are discussed in relation to the use of marine mammals for monitoring contaminant trends.

  6. Experimental Studies of NAK in a Simulated Space Environment

    NASA Astrophysics Data System (ADS)

    Gibson, M. A.; Sanzi, J.; Ljubanovic, D.

    Space fission power systems are being developed at the National Aeronautics and Space Administration (NASA) and Department of Energy (DOE) with a short term goal of building a full scale, non-nuclear, Technology Demonstration Unit (TDU) test at NASA's Glenn Research Center. Due to the geometric constraints, mass restrictions, and fairly high tempera- tures associated with space reactors, liquid metals are typically used as the primary coolant. A eutectic mixture of sodium (22 percent) and potassium (78 percent), or NaK, has been chosen as the coolant for the TDU with a total system capacity of approximately 55L. NaK, like all alkali metals, is very reactive, and warrants certain safety considerations. To adequately examine the risk associated with the personnel, facility, and test hardware during a potential NaK leak in the large scale TDU test, a small scale experiment was performed in which NaK was released in a thermal vacuum chamber under controlled conditions. The study focused on detecting NaK leaks in the vacuum environment as well as the molecular flow of the NaK vapor. This paper reflects the work completed during the NaK experiment and provides results and discussion relative to the findings.

  7. Application of SMIF isolation to lithography processes for contamination control

    NASA Astrophysics Data System (ADS)

    Zhu, Sheng-Bai

    2001-08-01

    Contamination control is particularly important in lithography processes because pattern defects are converted to wafers after each exposure. Contamination, by definition, is undesired matter or energy, which causes product defects or process instabilities, and, consequently, reduces yield and reliability. In lithography processes, particles, condensable hydrocarbosn, base molecules, moisture, and static electricity are examples of contaminants. Particles are inert minute objects, which interfere with the proper formation of circuit features. Condensable hydrocarbosn may cause optics hazing which reduces image homogeneity and energy transmission. Some Chemically Amplified Resists (CAR) are susceptible to molecular base contamination, resulting in image degradation such as T-topping. Moisture can affect the characteristics of photoresist, destabilizing photo-exposure and development processes. In combination with water, amine containing photoresist strippers can form hydroxyl ions that can attack aluminum and aluminum-copper alloys. Charged surfaces can tract and hold contaminants of opposite polarity. In case the electrical field exceeds the dielectric strength, ESD event occurs, often accompanied with damage of reticles, masks, or wafer circuits. With SMIF isolation technologies, yield loss due to defects and/or instabilities is minimized. Reticles, masks, and wafers are isolated form contamination sources through hermetic seal, in conjunction with particle/chemical filtration, and static shielding. Pressurization, inert gas purge, chemical absorbents, and electric grounding or air ionization are techniques of removing contaminants from the critical areas. For best performance, adequate selection of construction materials is critical. This paper discusses impacts of contamination on lithography processes and the possibility of solving such problems using SMIF isolation techniques. Theoretical models are developed and experimental data are presented.

  8. Catalytic extraction processing of contaminated scrap metal

    SciTech Connect

    Griffin, T.P.; Johnston, J.E.; Payea, B.M.; Zeitoon, B.M.

    1995-12-01

    Molten Metal Technology was awarded a contract to demonstrate the applicability of the Catalytic Extraction Process, a proprietary process that could be applied to US DOE`s inventory of low level mixed waste. This paper is a description of that technology, and included within this document are discussions of: (1) Program objectives, (2) Overall technology review, (3) Organic feed conversion to synthetic gas, (4) Metal, halogen, and transuranic recovery, (5) Demonstrations, (6) Design of the prototype facility, and (7) Results.

  9. Contaminant Attenuation Processes at Mining Sites

    EPA Science Inventory

    Monitored natural attenuation is sometimes used in combination with active treatment technologies to achieve site-specific remediation objectives. The global imprint of acid drainage problems at mining sites, however, is a clear reminder that in most cases natural processes are ...

  10. Method of treating contaminated HEPA filter media in pulp process

    DOEpatents

    Hu, Jian S.; Argyle, Mark D.; Demmer, Ricky L.; Mondok, Emilio P.

    2003-07-29

    A method for reducing contamination of HEPA filters with radioactive and/or hazardous materials is described. The method includes pre-processing of the filter for removing loose particles. Next, the filter medium is removed from the housing, and the housing is decontaminated. Finally, the filter medium is processed as pulp for removing contaminated particles by physical and/or chemical methods, including gravity, flotation, and dissolution of the particles. The decontaminated filter medium is then disposed of as non-RCRA waste; the particles are collected, stabilized, and disposed of according to well known methods of handling such materials; and the liquid medium in which the pulp was processed is recycled.

  11. Feasibility Process for Remediation of the Crude Oil Contaminated Soil

    NASA Astrophysics Data System (ADS)

    Keum, H.; Choi, H.; Heo, H.; Lee, S.; Kang, G.

    2015-12-01

    More than 600 oil wells were destroyed in Kuwait by Iraqi in 1991. During the war, over 300 oil lakes with depth of up to 2m at more than 500 different locations which has been over 49km2. Therefore, approximately 22 million m3was crude oil contaminated. As exposure of more than 20 years under atmospheric conditions of Kuwait, the crude oil has volatile hydrocarbons and covered heavy oily sludge under the crude oil lake. One of crude oil contaminated soil which located Burgan Oilfield area was collected by Kuwait Oil Company and got by H-plus Company. This contaminated soil has about 42% crude oil and could not biodegraded itself due to the extremely high toxicity. This contaminated soil was separated by 2mm sieve for removal oil sludge ball. Total petroleum hydrocarbons (TPH) was analysis by GC FID and initial TPH concentration was average 48,783 mg/kg. Ten grams of the contaminated soil replaced in two micro reactors with 20mL of bio surfactant produce microorganism. Reactor 1 was added 0.1g powder hemoglobin and other reactor was not added hemoglobin at time 0 day. Those reactors shake 120 rpm on the shaker for 7 days and CO2 produced about 150mg/L per day. After 7 days under the slurry systems, the rest days operated by hemoglobin as primary carbon source for enhanced biodegradation. The crude oil contaminated soil was degraded from 48,783mg/kg to 20,234mg/kg by slurry process and final TPH concentration degraded 11,324mg/kg for 21days. Therefore, highly contaminated soil by crude oil will be combined bio slurry process and biodegradation process with hemoglobin as bio catalytic source. Keywords: crude-oil contaminated soil, bio slurry, biodegradation, hemoglobin ACKOWLEDGEMENTS This project was supported by the Korea Ministry of Environment (MOE) GAIA Program

  12. Long-length contaminated equipment burial containers fabrication process procedures

    SciTech Connect

    McCormick, W.A., Fluor Daniel Hanford

    1997-03-11

    These special process procedures cover the detailed step-by-step procedures required by the supplier who will manufacture the Long-Length Contaminated Equipment (LLCE) Burial Container design. Also included are detailed step-by-step procedures required by the disposal process for completion of the LLCE Burial Containers at Hanford.

  13. Treating contaminated organics using the DETOX process

    SciTech Connect

    Elsberry, K.D.; Dhooge, P.M.

    1993-05-01

    Waste matrices containing organics, radionuclides, and metals pose difficult problems in waste treatment and disposal when the organic compounds and/or metals are considered to be hazardous. This paper describes the results of bench-scale studies of DETOX applied to the components of liquid mixed wastes, with the goal of establishing parameters for designing a prototype waste treatment unit. Apparent organic reaction rate orders and the dependence of apparent reaction rate on solution composition and the contact area were measured for vacuum pump oil scintillation fluids, and trichloroethylene. Reaction rate was superior in chloride-based solutions and was proportional to the contact area above about 2% w/w loading of organic. Oxidations in a 4-liter volume, mixed bench-top reactor have given destruction efficiencies of 99.9999 + % for common organics. Reaction rates achieved in the mixed bench-top reactor were one to two orders of magnitude greater than had been achieved in unmixed reactions; a thoroughly mixed reactor should be capable of oxidizing 10 to 100 + grams of organic per liter-hour. Results are also presented on the solvation efficiency of DETOX for mercury, cerium, and neodymium, and for removal/destruction of organics sorbed on vermiculite. The next stage of development will be converting the bench-top unit to continuous processing.

  14. Reducing the potential for processing contaminant formation in cereal products

    PubMed Central

    Curtis, Tanya Y.; Postles, Jennifer; Halford, Nigel G.

    2014-01-01

    Processing contaminants may be defined as substances that are produced in a food when it is cooked or processed, are not present or are present at much lower concentrations in the raw, unprocessed food, and are undesirable either because they have an adverse effect on product quality or because they are potentially harmful. The presence of very low levels of processing contaminants in common foods is becoming an increasingly important issue for the food industry, as developments in analytical techniques and equipment bring foods under closer and closer scrutiny. This review considers the formation of lipid oxidation products, hydrogenation of polyunsaturated fatty acids to prevent lipid oxidation and the associated risk of trans fatty acid formation. The formation of acrylamide in the Maillard reaction is described, as well as the genetic and agronomic approaches being taken to reduce the acrylamide-forming potential of cereal grain. The multiple routes for the formation of furan and associated chemicals, including hydroxymethylfurfuryl, are also described. The evolving regulatory and public perception situations for these processing contaminants and their implications for the cereal supply chain are discussed, emphasising the need for cereal breeders to engage with the contaminants issue. PMID:24882936

  15. Analysis of Zinc 65 Contamination after Vacuum Thermal Process

    SciTech Connect

    Korinko, Paul S.; Tosten, Michael H.

    2013-01-01

    Radioactive contamination with a gamma energy emission consistent with {sup 65}Zn was detected in a glovebox following a vacuum thermal process. The contaminated components were removed from the glovebox and subjected to examination. Selected analytical techniques were used to determine the nature of the precursor material, i.e., oxide or metallic, the relative transferability of the deposit and its nature. The deposit was determined to be borne from natural zinc and was further determined to be deposited as a metallic material from vapor.

  16. Preliminary Results of Cleaning Process for Lubricant Contamination

    NASA Astrophysics Data System (ADS)

    Eisenmann, D.; Brasche, L.; Lopez, R.

    2006-03-01

    Fluorescent penetrant inspection (FPI) is widely used for aviation and other components for surface-breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. Prior to FPI, components are cleaned using a variety of cleaning methods which are selected based on the alloy and the soil types which must be removed. It is also important that the cleaning process not adversely affect the FPI process. There are a variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. To assess the effectiveness of typical cleaning processes on removal of these contaminants, a study was initiated at an airline overhaul facility. Initial results of the cleaning study for lubricant contamination in nickel, titanium and aluminum alloys will be presented.

  17. Particle contamination formation and detection in magnetron sputtering processes

    SciTech Connect

    Selwyn, G.S.; Weiss, C.A.; Sequeda, F.; Huang, C.

    1996-10-01

    Defects caused by particulate contamination are an important concern in the fabrication of thin film products. Often, magnetron sputtering processes are used for this purpose. Particle contamination can cause electrical shorting, pin holes, problems with photolithography, adhesion failure, as well as visual and cosmetic defects. Particle contamination generated during thin film processing can be detected using laser light scattering, a powerful diagnostic technique that provides real-time, {ital in-situ} imaging of particles > 0.3 {mu}m in diameter. Using this technique, the causes, sources and influences on particles in plasma and non-plasma and non-plasma processes may be independently evaluated and corrected. Several studies employing laser light scattering have demonstrated both homogeneous and heterogeneous causes of particle contamination. In this paper, we demonstrate that the mechanisms for particle generation, transport and trapping during magnetron sputter deposition are different from the mechanisms reported in previously studied plasma etch processes. During magnetron sputter deposition, one source of particle contamination is linked to portions of the sputtering target surface exposed to weaker plasma density. In this region, film redeposition is followed by filament or nodule growth and enhanced trapping which increases filament growth. Eventually the filaments effectively ``short circuit`` the sheath, causing high currents to flow through these features. This, in turn, causes heating failure of the filament fracturing and ejecting the filaments into the plasma and onto the substrate. Evidence of this effect has been observed in semiconductor (IC) fabrication and storage disk manufacturing. Discovery of this mechanism in both technologies suggests that this mechanism may be universal to many sputtering processes.

  18. Electrowinning process with electrode compartment to avoid contamination of electrolyte

    SciTech Connect

    Poa, D.S.; Pierce, R.D.; Mulcahey, T.P.; Johnson, G.K.

    1993-07-06

    A process is described of electrolytically recovering a metal from an oxide of the metal comprising the steps of: (a) providing an electrolytic cell including a molten salt electrolyte containing the metal oxide and one or more halide salts of the metal, a pair of spaced apart electrodes in the electrolyte, and a source of electrical voltage to the electrodes, one of the electrodes being an anode and a source of particulate carbon contamination of the electrolyte during operation of the cell, (b) operating the cell to recover the metal as an element at the other electrode while confining the contaminant to a zone in the electrolyte about the one electrode, and (c) periodically removing the contaminant from the electrolyte zone while interrupting operation of the cell.

  19. Industrial-Scale Processes For Stabilizing Radioactively Contaminated Mercury Wastes

    SciTech Connect

    Broderick, T. E.; Grondin, R.

    2003-02-24

    This paper describes two industrial-scaled processes now being used to treat two problematic mercury waste categories: elemental mercury contaminated with radionuclides and radioactive solid wastes containing greater than 260-ppm mercury. The stabilization processes were developed by ADA Technologies, Inc., an environmental control and process development company in Littleton, Colorado. Perma-Fix Environmental Services has licensed the liquid elemental mercury stabilization process to treat radioactive mercury from Los Alamos National Laboratory and other DOE sites. ADA and Perma-Fix also cooperated to apply the >260-ppm mercury treatment technology to a storm sewer sediment waste collected from the Y-12 complex in Oak Ridge, TN.

  20. Process for treating waste water having low concentrations of metallic contaminants

    DOEpatents

    Looney, Brian B; Millings, Margaret R; Nichols, Ralph L; Payne, William L

    2014-12-16

    A process for treating waste water having a low level of metallic contaminants by reducing the toxicity level of metallic contaminants to an acceptable level and subsequently discharging the treated waste water into the environment without removing the treated contaminants.

  1. Processes affecting the remediation of chromium-contaminated sites.

    PubMed Central

    Palmer, C D; Wittbrodt, P R

    1991-01-01

    The remediation of chromium-contaminated sites requires knowledge of the processes that control the migration and transformation of chromium. Advection, dispersion, and diffusion are physical processes affecting the rate at which contaminants can migrate in the subsurface. Heterogeneity is an important factor that affects the contribution of each of these mechanisms to the migration of chromium-laden waters. Redox reactions, chemical speciation, adsorption/desorption phenomena, and precipitation/dissolution reactions control the transformation and mobility of chromium. The reduction of CrVI to CrIII can occur in the presence of ferrous iron in solution or in mineral phases, reduced sulfur compounds, or soil organic matter. At neutral to alkaline pH, the CrIII precipitates as amorphous hydroxides or forms complexes with organic matter. CrIII is oxidized by manganese dioxide, a common mineral found in many soils. Solid-phase precipitates of hexavalent chromium such as barium chromate can serve either as sources or sinks for CrVI. Adsorption of CrVI in soils increases with decreasing chromium concentration, making it more difficult to remove the chromium as the concentration decreases during pump-and-treat remediation. Knowledge of these chemical and physical processes is important in developing and selecting effective, cost-efficient remediation designs for chromium-contaminated sites. PMID:1935849

  2. Regulation of cough by neuronal Na(+)-K(+) ATPases.

    PubMed

    Canning, Brendan J; Farmer, David G S

    2015-06-01

    The Na(+)-K(+) ATPases play an essential role in establishing the sodium gradients in excitable cells. Multiple isoforms of the sodium pumps have been identified, with tissue and cell specific expression patterns. Because the vagal afferent nerves regulating cough must be activated at sustained high frequencies of action potential patterning to achieve cough initiation thresholds, it is a certainty that sodium pump function is essential to maintaining cough reflex sensitivities in health and in disease. The mechanisms by which Na(+)-K(+) ATPases regulate bronchopulmonary vagal afferent nerve excitability are reviewed as are potential therapeutic strategies targeting the sodium pumps in cough. PMID:26048736

  3. Characterization of Organic Contamination in Semiconductor Manufacturing Processes

    NASA Astrophysics Data System (ADS)

    Nutsch, A.; Beckhoff, B.; Bedana, G.; Borionetti, G.; Codegoni, D.; Grasso, S.; Guerinoni, G.; Leibold, A.; Müller, M.; Otto, M.; Pfitzner, L.; Polignano, M.-L.; De Simone, D.; Frey, L.

    2009-09-01

    The impact of organic contamination on wafer surfaces on the functionality of nanostructures and advanced microelectronics becomes crucial as the continuously shrinking feature sizes become similar to the dimensions of molecules and clusters of molecules. Especially, manufacturing of highly integrated circuits requires clean surfaces as processes might cause defects involving for example carbon and sulfur. The approach to study organic contamination on wafer samples using different analytical tools enables the detection of the whole range of organic compounds including non-volatile and volatile ones. For the studies the methods used were synchrotron radiation based Near Edge X-ray Absorption Fine Structure (NEXAFS) in the soft X-Ray range at the absorption edges of light elements (e.g. C, N, O, F) combined with reference-free Total-reflection X-Ray Fluorescence (TXRF) analysis, Thermal Desorption Gas Chromatography Mass Spectrometry (TD-GCMS), and Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS). TOF-SIMS analysis of the surfaces of wafers from the lithography process after ashing showed sulfur compounds related to resist residues not identified by TD-GCMS. The source of the sulfur is assumed to be a photo acid generator of the resist. It was proven by TD-GCMS and TXRF-NEXAFS that final clean and packaging were the process steps during which detectable organic contamination was transferred to the wafer surface during wafer manufacturing. Multi-criteria evaluation of the TXRF NEXAFS spectra was used to compare the results with TD-GCMS. The TXRF-NEXAFS results are in good agreement with the TD-GCMS results. The advantage of TXRF-NEXAFS and TOF-SIMS are the sensitivity for organic contaminants that are not detectable by TD-GCMS, due to their high boiling point and low vapor pressures.

  4. Stainless Steel NaK Circuit Integration and Fill Submission

    NASA Technical Reports Server (NTRS)

    Garber, Anne E.

    2006-01-01

    The Early Flight Fission Test Facilities (EFF-TF) team has been tasked by the Marshall Space Flight Center Nuclear Systems Office to design, fabricate, and test an actively pumped alkali metal flow circuit. The system, which was originally designed to hold a eutectic mixture of sodium potassium (NaK), was redesigned to hold lithium; but due to a shift in focus, it is once again being prepared for use with NaK. Changes made to the actively pumped, high temperature loop include the replacement of the expansion reservoir, addition of remotely operated valves, and modification of the support table. Basic circuit components include: reactor segment, NaK to gas heat exchanger, electromagnetic (EM) liquid metal pump, load/drain reservoir, expansion reservoir, instrumentation, and a spill reservoir. A 37-pin partial-array core (pin and flow path dimensions are the same as those in a full design) was selected for fabrication and test. This document summarizes the integration and fill of the pumped liquid metal NaK flow circuit.

  5. Process for minimizing solids contamination of liquids from coal pyrolysis

    DOEpatents

    Wickstrom, Gary H.; Knell, Everett W.; Shaw, Benjamin W.; Wang, Yue G.

    1981-04-21

    In a continuous process for recovery of liquid hydrocarbons from a solid carbonaceous material by pyrolysis of the carbonaceous material in the presence of a particulate source of heat, particulate contamination of the liquid hydrocarbons is minimized. This is accomplished by removing fines from the solid carbonaceous material feed stream before pyrolysis, removing fines from the particulate source of heat before combining it with the carbonaceous material to effect pyrolysis of the carbonaceous material, and providing a coarse fraction of reduced fines content of the carbon containing solid residue resulting from the pyrolysis of the carbonaceous material before oxidizing carbon in the carbon containing solid residue to form the particulate source of heat.

  6. Electrowinning process with electrode compartment to avoid contamination of electrolyte

    DOEpatents

    Poa, Davis S.; Pierce, R. Dean; Mulcahey, Thomas P.; Johnson, Gerald K.

    1993-01-01

    An electrolytic process and apparatus for reducing calcium oxide in a molten electrolyte of CaCl.sub.2 -CaF.sub.2 with a graphite anode in which particles or other contamination from the anode is restricted by the use of a porous barrier in the form of a basket surrounding the anode which may be removed from the electrolyte to burn the graphite particles, and wherein the calcium oxide feed is introduced to the anode compartment to increase the oxygen ion concentration at the anode.

  7. Electrowinning process with electrode compartment to avoid contamination of electrolyte

    SciTech Connect

    Poa, D.S.; Pierce, R.D.; Mulcahey, T.P.; Johnson, G.K.

    1991-12-31

    An electrolytic process and apparatus for reducing calcium oxide in a molten electrolyte of CaCl{sub 2}-CaF{sub 2} with a graphite anode in which particles or other contamination from the anode is restricted by the use of a porous barrier in the form of a basket surrounding the anode which may be removed from the electrolyte to burn the graphite particles, and wherein the calcium oxide feed is introduced to the anode compartment to increase the oxygen ion concentration at the anode.

  8. Size Distribution of NaK Droplets Released During Rorsat Reactor Core Ejection

    NASA Astrophysics Data System (ADS)

    Wiedemann, C.; Oswald, M.; Stabroth, S.; Klinkrad, H.; Vörsmann, P.

    NaK droplets consist of eutectic sodium-potassium alloy and have been released during RORSAT reactor core ejections mostly on orbits close to 950 km altitude. They contributed to the space debris environment in the centimeter and millimeter size regime. NaK droplets have been modeled before in ESA's MASTER Debris and Meteoroid Environment Model. The approach is currently revised for the MASTER 2005 upgrade. The new NaK model gives estimations of the parameters of the size distribution function, which are based on physical relations only. This physical approach confirms NASA radar observations. The core ejection causes an opening of the primary coolant circuit. The liquid coolant is released into space forming droplets up to a diameter of 5.5 cm. The reactor design is investigated to understand the possible mechanisms that cause the droplets generation. It is likely that the droplet generation process can be both capillary jet breakup and atomization. This paper presents results of the estimation of droplets sizes. A droplet size distribution is introduced, which is scientifically justified. The physical process of atomization resp. liquid jet breakup is considered, to derive the parameters of the size distribution function. The introduction of an improved distribution function is important. So far the cumulative size distribution function was a combination of several fitting curve segments to agree with measured data. The definition of several functions results in a large number of parameters. This drawback is corrected. The droplet size can be defined as function of the orifice diameter. The droplets sizes are related to the parameters of the size distribution function. The size distribution function shall contain only two parameters, which can be derived from the orifice diameter and the atomization conditions. In this way scientifically based estimations of the parameters are introduced. An estimation of the maximum droplet diameter assuming capillary jet

  9. 9 CFR 381.94 - Contamination with Microorganisms; process control verification criteria and testing; pathogen...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Contamination with Microorganisms... § 381.94 Contamination with Microorganisms; process control verification criteria and testing; pathogen... maintaining process controls sufficient to prevent fecal contamination. FSIS shall take further action...

  10. Contamination Revealed by Indicator Microorganism Levels during Veal Processing.

    PubMed

    Bosilevac, Joseph M; Wang, Rong; Luedtke, Brandon E; Wheeler, Tommy L; Koohmaraie, Mohammad

    2016-08-01

    During site visits of veal processors, the U.S. Department of Agriculture, Food Safety Inspection Service (FSIS) has reported processing deficiencies that likely contribute to increased levels of veal contamination. Here, we report the results of measuring aerobic plate count bacteria (APC), Enterobacteriaceae, coliforms (CF), and Escherichia coli during eight sample collections at five veal processors to assess contamination during the harvest of bob veal and formula-fed veal before (n = 5 plants) and after (n = 3 plants) changes to interventions and processing practices. Hides of veal calves at each plant had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 6.02 to 8.07, 2.95 to 5.24, 3.28 to 5.83, and 3.08 to 5.59, respectively. Preintervention carcasses had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 3.08 to 5.22, 1.16 to 3.47, 0.21 to 3.06, and -0.07 to 3.10, respectively, before and 2.72 to 4.50, 0.99 to 2.76, 0.69 to 2.26, and 0.33 to 2.12, respectively, after changes were made to improve sanitary dressing procedures. Final veal carcasses had mean log CFU/100 cm(2) APC, Enterobacteriaceae, CF, and E. coli of 0.36 to 2.84, -0.21 to 1.59, -0.23 to 1.59, and -0.38 to 1.45 before and 0.44 to 2.64, -0.16 to 1.33, -0.42 to 1.20, and 0.48 to 1.09 after changes were made to improve carcass-directed interventions. Whereas the improved dressing procedures resulted in improved carcass cleanliness, the changes to carcass-directed interventions were less successful, and veal processors are urged to use techniques that ensure uniform and consistent delivery of antimicrobials to carcasses. Analysis of results comparing bob veal to formula-fed veal found bob veal hides, preintervention carcasses, and final carcasses to have increased (P < 0.05) APC, Enterobacteriaceae, CF, and E. coli (with the exception of hide Enterobacteriaceae; P > 0.05) relative to formula fed veal. When both veal categories were harvested at the same plant on

  11. Contamination and changes of food factors during processing with modeling applications-safety related issues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical and microbiological contamination of food during processing and preservation can result in foodborne illness outbreaks and food poisoning. Chemical contaminations can occur through exposure of foods to illegal additives, pesticides and fertilizer residues, toxic compounds formed by microbes...

  12. Contaminated Metal Components in Dismantling by Hot Cutting Processes

    SciTech Connect

    Cesari, Franco G.; Conforti, Gianmario; Rogante, Massimo; Giostri, Angelo

    2006-07-01

    During the preparatory dismantling activities of Caorso's Nuclear Power Plant (NPP), an experimental campaign using plasma and oxyacetylene metal cutting processes has been performed and applied to plates and tubes exposed to the coolant steam of the reactor. The plant (Boiling Water Reactor, 870 MWe) was designed and built in the 70's, and it was fully operating by 1981 to 1986 being shut down after 1987 Italy's poll that abrogated nuclear power based on U235 fission. The campaign concerns no activated materials, even if the analyses have been performed of by use contaminated components under the free release level, not yet taking into account radioactivity. In this paper, the parameters related to inhalable aerosol, solid and volatile residuals production have been, studied during hot processes which applies the same characteristics of the cutting in field for the dismantling programs of Caorso NPP. The technical parameters such as cutting time and cutting rate vs. pipe diameter/thickness/schedule or plate thickness for ferritic alloys and the emissions composition coming from the sectioning are also reported. The results underline the sort of trouble that can emerge in the cutting processes, in particular focusing on the effects comparison between the two cutting processes and the chemical composition of powders captured by filtering the gaseous emission. Some preliminary considerations on methodology to be used during the dismantling have been presented. (authors)

  13. Enhanced bioremediation of PAH contaminated soils from coal processing sites

    SciTech Connect

    Joshi, M.M.; Lee, S.

    1995-12-31

    The polycyclic aromatic hydrocarbons (PAH) are a potential hazard to health due to their carcinogenic, mutagenic nature and acute toxicity and there is an imminent need for remediation of PAH contaminated soils abounding the several coke oven and town gas sites. Aerobic biological degradation of PAHs is an innovative technology and has shown high decontamination efficiencies, complete mineralization of contaminants, and is environmentally safe. The present study investigates the remediation of PAH contaminated soils achieved using Acinetobacter species and fungal strain Phanerochaete Chrysosporium. The soil used for the experiments was an industrially contaminated soil obtained from Alberta Research Council (ARC) primary cleanup facility, Alberta, Canada. Soil characterization was done using High Performance Liquid Chromatography (HPLC) to qualitatively and quantitatively determine the contaminants in the soil. Artificially contaminated soil was also used for some experiments. All the experiments were conducted under completely mixed conditions with suitable oxygen and nutrient amendments. The removal efficiency obtained for various PAHs using the two microorganisms was compared.

  14. Social Marketing in Malaysia: Cognitive, Affective, and Normative Mediators of the TAK NAK Antismoking Advertising Campaign.

    PubMed

    Lee, Wonkyong Beth; Fong, Geoffrey T; Dewhirst, Timothy; Kennedy, Ryan D; Yong, Hua-Hie; Borland, Ron; Awang, Rahmat; Omar, Maizurah

    2015-01-01

    Antismoking mass media campaigns are known to be effective as part of comprehensive tobacco control programs in high-income countries, but such campaigns are relatively new in low- and middle-income countries and there is a need for strong evaluation studies from these regions. This study examines Malaysia's first national antismoking campaign, TAK NAK. The data are from the International Tobacco Control Malaysia Survey, which is an ongoing cohort survey of a nationally representative sample of adult smokers (18 years and older; N = 2,006). The outcome variable was quit intentions of adult smokers, and the authors assessed the extent to which quit intentions may have been strengthened by exposure to the antismoking campaign. The authors also tested whether the impact of the campaign on quit intentions was related to cognitive mechanisms (increasing thoughts about the harm of smoking), affective mechanisms (increasing fear from the campaign), and perceived social norms (increasing perceived social disapproval about smoking). Mediational regression analyses revealed that thoughts about the harm of smoking, fear arousal, and social norms against smoking mediated the relation between TAK NAK impact and quit intentions. Effective campaigns should prompt smokers to engage in both cognitive and affective processes and encourage consideration of social norms about smoking in their society. PMID:26054867

  15. 9 CFR 310.25 - Contamination with microorganisms; process control verification criteria and testing; pathogen...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Contamination with microorganisms... CERTIFICATION POST-MORTEM INSPECTION § 310.25 Contamination with microorganisms; process control verification... controls sufficient to prevent fecal contamination. FSIS shall take further action as appropriate to...

  16. Contamination by slow diffusers in ion implantation processes: The examples of molybdenum and tungsten

    NASA Astrophysics Data System (ADS)

    Polignano, M. L.; Mica, I.; Barbarossa, F.; Galbiati, A.; Grasso, S.; Soncini, V.

    2015-08-01

    A procedure to measure molybdenum and tungsten contamination in implantation processes by DLTS (Deep Level Transient Spectroscopy) is defined and calibrated for the evaluation of molybdenum and tungsten contaminant dose. The obtained calibrations are used to study molybdenum contamination in BF2 implantations and tungsten contamination by sputtering from a previously contaminated wafer holder. In molybdenum-implanted samples, the molybdenum level located 0.3 eV above valence band is revealed only. In tungsten-implanted samples, two levels are revealed. One of these levels is the tungsten-related hole trap located 0.4 eV above valence band. The other level does not correspond to any tungsten-related level, however it is related to the presence of tungsten and to the sample preparation process. The SPV (Surface Photovoltage) measurement sensitivity to tungsten contamination was also tested, and it was found much lower than the DLTS sensitivity, due to the low tungsten diffusivity. This procedure was used to evaluate contamination in implantation processes. In BF2 implantations, in addition to molybdenum, tungsten contamination is found. Molybdenum and tungsten contamination is found in boron implantation too. The tungsten contamination induced by implantation in a previously contaminated implanter was quantified, and the efficiency of arsenic implantation as a decontamination process was tested. Finally, it was shown that TXRF (Total reflection X-ray Fluorescence) is much less sensitive than DLTS for monitoring tungsten contamination.

  17. INNOVATIVE PROCESSES FOR RECLAMATION OF CONTAMINATED SUBSURFACE ENVIRONMENTS

    EPA Science Inventory

    Research to better assess the capabilities and limitations of fixed-film bioreactors for removing selected organic contaminants from ground water or from contaminated vapor streams produced by air stripping of polluted ground water and by soil venting operations is described. ...

  18. INNOVATIVE PROCESS FOR RECLAMATION OF CONTAMINATED SUBSURFACE ENVIRONMENTS

    EPA Science Inventory

    Research to better assess the capabilities and limitations of fixed-film bioreactors for removing selected organic contaminants from ground water or from contaminated vapor streams produced by air stripping of polluted ground water and by soil venting operations is described. ork...

  19. Characterization of Contaminants from a Sanitized Milk Processing Plant

    PubMed Central

    Cleto, Sara; Matos, Sónia; Kluskens, Leon; Vieira, Maria João

    2012-01-01

    Milk processing lines offer a wide variety of microenvironments where a diversity of microorganisms can proliferate. We sampled crevices and junctions where, due to deficient reach by typical sanitizing procedures, bacteria can survive and establish biofilms. The sampling sites were the holding cell, cold storage tank, pasteurizer and storage tank - transfer pump junction. The culturable bacteria that were isolated after the sanitation procedure were predominantly Pseudomonas spp., Serratia spp, Staphylococcus sciuri and Stenotrophomonas maltophilia. We assayed several phenotypic characteristics such as the ability to secrete enzymes and siderophores, as well as the capacity of the strains to form biofilms that might contribute to their survival in a mixed species environment. The Pseudomonas spp. isolates were found to either produce proteases or lecithinases at high levels. Interestingly, protease production showed an inverse correlation with siderophore production. Furthermore, all of the Serratia spp. isolates were strong biofilm formers and spoilage enzymes producers. The organisms identified were not mere contaminants, but also producers of proteins with the potential to lower the quality and shelf-life of milk. In addition, we found that a considerable number of the Serratia and Pseudomonas spp. isolated from the pasteurizer were capable of secreting compounds with antimicrobial properties. PMID:22761957

  20. Long and short time variations of the Na/K ratio in the exosphere of Mercury.

    NASA Astrophysics Data System (ADS)

    Mura, Alessandro; Lammer, Helmut; Wurz, Peter; Orsini, Stefano; Milillo, Anna; Mangano, Valeria; Lichtenegger, Herbert; Scherf, Manuel; Khodachenko, Maxim; Pfleger, Martin

    2014-05-01

    Here we present the results of our model for the short-time and yearly variations of the Sodium and Potassium exosphere of Mercury. Such surface-bounded exosphere is produced by release processes occurring at the planetary surface, such as ion sputtering, thermal- or photon-stimulated desorption. The amount of surface Sodium or Potassium that is available for release, however, is limited. Those release processes deplete the surface in Na and K, which is continuously refilled by diffusion from the interior of regolith grains or by chemical sputtering. Ejected particles may either escape the gravity field, assisted by the radiation pressure acceleration, or be photoionized, or fall back onto the surface. Falling particles will stick to the surface. A Montecarlo model, simulating all these processes, is used to obtain the exosphere densities and the Na/K ratio, taking into account the planet's orbit and rotation speed. The influence of variations of the solar wind precipitation (i.e., CMEs) is also included. We compare this model with either ground- and space-based observations of the exosphere and tail to evaluate the effectiveness of each source process. We find that including a source process which effectiveness is proportional to the precipitation of solar wind protons, is necessary to explain most of the available observations in both qualitative and quantitative way. We find that, to reproduce dawn-dusk asymmetries, we need to include the rotation of Mercury's surface in the model. After finding the correct model parameter by calibrating the model with observation, we simulate the short-term and yearly variations of Na/K.

  1. Surface photovoltage analysis of iron contamination in silicon processing and the relation to gate oxide integrity

    NASA Astrophysics Data System (ADS)

    Henley, Worth B.

    1995-09-01

    Surface photovoltage (SPV), a contactless optical technique for measuring minority carrier lifetime, is used to quantify the relationship between silicon iron contamination level and thin gate oxide integrity. Iron concentration levels in the range of 1 X 1010 cm-3 to 5 X 1013 cm-3 are evaluated for oxide thicknesses of 8 to 20 nm. Ramp voltage electrical breakdown and time dependant dielectric breakdown measurement on the iron contaminated gate oxide capacitors are reported. Distinct iron contamination threshold limits based on defect density and gate oxide integrity evaluate cleaning efficiencies and metallic cross contamination effects during thermal processing contamination. Iron-silicide precipitation kinetics are investigated by the lifetime analysis procedure.

  2. CONTAMINATED PROCESS EQUIPMENT REMOVAL FOR THE D&D OF THE 232-Z CONTAMINATED WASTE RECOVERY PROCESS FACILITY AT THE PLUTONIUM FINISHING PLANT (PFP)

    SciTech Connect

    HOPKINS, A.M.; MINETTE, M.J.; KLOS, D.B.

    2007-01-25

    This paper describes the unique challenges encountered and subsequent resolutions to accomplish the deactivation and decontamination of a plutonium ash contaminated building. The 232-Z Contaminated Waste Recovery Process Facility at the Plutonium Finishing Plant was used to recover plutonium from process wastes such as rags, gloves, containers and other items by incinerating the items and dissolving the resulting ash. The incineration process resulted in a light-weight plutonium ash residue that was highly mobile in air. This light-weight ash coated the incinerator's process equipment, which included gloveboxes, blowers, filters, furnaces, ducts, and filter boxes. Significant airborne contamination (over 1 million derived air concentration hours [DAC]) was found in the scrubber cell of the facility. Over 1300 grams of plutonium held up in the process equipment and attached to the walls had to be removed, packaged and disposed. This ash had to be removed before demolition of the building could take place.

  3. Design of a Mechanical NaK Pump for Fission Space Power

    NASA Technical Reports Server (NTRS)

    Mireles, Omar R.; Bradley, David E.; Godfroy, Thomas

    2011-01-01

    Alkali liquid metal cooled fission reactor concepts are under development for spaceflight power requirements. One such concept utilizes a sodium-potassium eutectic (NaK) as the primary loop working fluid, which has specific pumping requirements. Traditionally, electromagnetic linear induction pumps have been used to provide the required flow and pressure head conditions for NaK systems but they can be limited in performance, efficiency, and number of available vendors. The objective of the project was to develop a mechanical NaK centrifugal pump that takes advantages of technology advances not available in previous liquid metal mechanical pump designs. This paper details the design, build, and performance test of a mechanical NaK pump developed at NASA Marshall Space Flight Center. The pump was designed to meet reactor cooling requirements using commercially available components modified for high temperature NaK service.

  4. Development of a Pulp Process Treating Contaminated HEPA Filters (III)

    SciTech Connect

    Hu, J. S.; Ramer, J.; Argyle, M. D.; Demmer, R. L.

    2002-02-28

    The Pulp Process (PP) Treatment option was conceived as a replacement for the current Filter Leaching System (FLS). The FLS has operated at the Idaho Nuclear Technology and Engineering Center of the Idaho National Engineering and Environmental Laboratory since 1995 to treat radioactive, mixed waste HEPA filters. In recent years, the FLS has exhibited difficulty in removing mercury from the HEPA filters as the concentration of mercury in the spent HEPA filters has increased. The FLS leaches and washes the whole filter without any preparation or modification. The filter media and the trapped calcine particles are confined in a heavy filter housing that contributes to poor mixing zones around the edges of the filter, low media permeability, channeling of the liquid through cracks and tears in the filter media, and liquid retention between leach and rinse cycles. In the PP, the filter media and the trapped calcine particles are separated from the filter housing and treated as a pulp, taking advantage of improved contact with the leach solution that cannot be achieved when the media is still in the HEPA filter housing. In addition to removing the mercury more effectively, the PP generates less volume of liquid waste, requires a shorter leach cycle time, and possesses the versatility for treating filters of different sizes. A series of tests have been performed in the laboratory to demonstrate the advantages of the PP concept. These tests compare the PP with the FLS under controlled conditions that simulate the current operating parameters. A prior study using blended feed, a mixture of shredded clean HEPA filter media and non-radioactive calcine particles, indicated that the PP would significantly increases the calcine dissolution percentages. In this study, hazardous-metal contaminated HEPA filter media was studied. The results of side-by-side tests indicated that the PP increased the mercury removal percentage by 80% and might be a solution to the mercury removal

  5. Collisional transfer of population and orientation in NaK.

    PubMed

    Wolfe, C M; Ashman, S; Bai, J; Beser, B; Ahmed, E H; Lyyra, A M; Huennekens, J

    2011-05-01

    Collisional satellite lines with |ΔJ| ≤ 58 have been identified in recent polarization spectroscopy V-type optical-optical double resonance (OODR) excitation spectra of the Rb(2) molecule [H. Salami et al., Phys. Rev. A 80, 022515 (2009)]. Observation of these satellite lines clearly requires a transfer of population from the rotational level directly excited by the pump laser to a neighboring level in a collision of the molecule with an atomic perturber. However to be observed in polarization spectroscopy, the collision must also partially preserve the angular momentum orientation, which is at least somewhat surprising given the extremely large values of ΔJ that were observed. In the present work, we used the two-step OODR fluorescence and polarization spectroscopy techniques to obtain quantitative information on the transfer of population and orientation in rotationally inelastic collisions of the NaK molecules prepared in the 2(A)(1)Σ(+)(v' = 16, J' = 30) rovibrational level with argon and potassium perturbers. A rate equation model was used to study the intensities of these satellite lines as a function of argon pressure and heat pipe oven temperature, in order to separate the collisional effects of argon and potassium atoms. Using a fit of this rate equation model to the data, we found that collisions of NaK molecules with potassium atoms are more likely to transfer population and destroy orientation than collisions with argon atoms. Collisions with argon atoms show a strong propensity for population transfer with ΔJ = even. Conversely, collisions with potassium atoms do not show this ΔJ = even propensity, but do show a propensity for ΔJ = positive compared to ΔJ = negative, for this particular initial state. The density matrix equations of motion have also been solved numerically in order to test the approximations used in the rate equation model and to calculate fluorescence and polarization spectroscopy line shapes. In addition, we have measured

  6. Scald tank water and foam as sources of carcass contamination during early poultry processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Salmonella remains a leading cause of bacterial foodborne illness in the United States, with poultry consumption associated with forty percent of outbreaks for which vehicles are identified. Identifying sources of Salmonella contamination and cross-contamination within poultry processing is imperat...

  7. Na/K ATPase inhibition by digitalis-like factors in neonates

    SciTech Connect

    Bottorff, M.B.; Songu-Mize, E.; Hoon, T.J.; Phelps, S.J.; Kamper, C.A.

    1986-03-01

    At the authors institution, 48% of neonates < 1 month of age had false-positive digoxin immunoassay determinations while not receiving digoxin, presumably due to an endogenous digoxin-like immunoreactive substance (DLIS) in the plasma. Plasma from 3 neonates positive for DLIS by fluorescence polarization immunoassay (FPIA) was evaluated for inhibitory activity on human red blood cell (RBC) Na/K ATPase. Neonatal plasma aliquots containing DLIS concentrations (conc) of 0.24, 0.37, 0.43, 0.49 and 0.61 ng/ml (3.07 - 7.81 x 10/sup -10/M) were incubated with human RBC and /sup 86/Rb in order to measure /sup 86/Rb uptake inhibition with respect to DLIS negative neonatal plasma. /sup 86/Rb uptake inhibition by digoxin-spiked human serum (1.07 x 10/sup -10/ - 4.57 x 10/sup -6/M) was also measured. Percent inhibition vs. log molar conc plots for DLIS and digoxin were compared. DLIS inhibited Na/K ATPase in a linear fashion over the range studied. Comparing the linear portions of the conc-inhibition curves for digoxin and DLIS, the molar conc of digoxin producing 40% inhibition of /sup 86/Rb uptake is 333 times greater than the molar conc of DLIS producing similar inhibition. Therefore, DLIS in neonatal serum as measured by FPIA has approximately 300 times greater inhibitory activity than digoxin. The presence of circulating DLIS may reflect an adaptive or maladaptive response to some, as yet unknown, process early in life.

  8. A top specified boundary layer (TSBL) approximation approach for the simulation of groundwater contamination processes

    USGS Publications Warehouse

    Rubin, H.; Buddemeier, R.W.

    1996-01-01

    This paper presents improvements in the 'classical boundary layer' (CBL) approximation method to obtain simple but robust initial characterization of aquifer contamination processes. Contaminants are considered to penetrate into the groundwater through the free surface of the aquifer. The improved method developed in this study is termed the 'top specified boundary layer' (TSBL) approach. It involves the specification of the contaminant concentration at the top of the contaminated 'region of interest' (ROI), which is simulated as a boundary layer. the TSBL modification significantly improves the ability of the boundary layer method to predict the development of concentration profiles over both space and time. The TSBL method can be useful for the simulation of cases in which the contaminant concentration is prescribed at the aquifer's free surface as well as for cases in which the contaminant mass flux is prescribed at the surface.

  9. Role of protein dynamics in ion selectivity and allosteric coupling in the NaK channel

    PubMed Central

    Brettmann, Joshua B.; Urusova, Darya; Tonelli, Marco; Silva, Jonathan R.; Henzler-Wildman, Katherine A.

    2015-01-01

    Flux-dependent inactivation that arises from functional coupling between the inner gate and the selectivity filter is widespread in ion channels. The structural basis of this coupling has only been well characterized in KcsA. Here we present NMR data demonstrating structural and dynamic coupling between the selectivity filter and intracellular constriction point in the bacterial nonselective cation channel, NaK. This transmembrane allosteric communication must be structurally different from KcsA because the NaK selectivity filter does not collapse under low-cation conditions. Comparison of NMR spectra of the nonselective NaK and potassium-selective NaK2K indicates that the number of ion binding sites in the selectivity filter shifts the equilibrium distribution of structural states throughout the channel. This finding was unexpected given the nearly identical crystal structure of NaK and NaK2K outside the immediate vicinity of the selectivity filter. Our results highlight the tight structural and dynamic coupling between the selectivity filter and the channel scaffold, which has significant implications for channel function. NaK offers a distinct model to study the physiologically essential connection between ion conduction and channel gating. PMID:26621745

  10. Experimental Studies of NaK in a Simulated Space Environment

    NASA Technical Reports Server (NTRS)

    Gibons, Marc; Sanzi, James; Ljubanovic, Damir

    2011-01-01

    Space fission power systems are being developed at the National Aeronautics and Space Administration (NASA) and Department of Energy (DOE) with a short term goal of building a full scale, non-nuclear, Technology Demonstration Unit (TDU) test at NASA's Glenn Research Center. Due to the geometric constraints, mass restrictions, and fairly high temperatures associated with space reactors, liquid metals are typically used as the primary coolant. A eutectic mixture of sodium (22 percent) and potassium (78 percent), or NaK, has been chosen as the coolant for the TDU with a total system capacity of approximately 55 L. NaK, like all alkali metals, is very reactive, and warrants certain safety considerations. To adequately examine the risk associated with the personnel, facility, and test hardware during a potential NaK leak in the large scale TDU test, a small scale experiment was performed in which NaK was released in a thermal vacuum chamber under controlled conditions. The study focused on detecting NaK leaks in the vacuum environment as well as the molecular flow of the NaK vapor. This paper reflects the work completed during the NaK experiment and provides results and discussion relative to the findings.

  11. A review on Insulin plant (Costus igneus Nak).

    PubMed

    Hegde, Prakash K; Rao, Harini A; Rao, Prasanna N

    2014-01-01

    Costus igneus Nak and Costus pictus D. Don, commonly known as Spiral flag, is a member of Costaceae and a newly introduced plant in India from South and Central America. It is a perennial, upright, spreading plant reaching about two feet tall, with spirally arranged leaves and attractive flowers. In southern India, it usually grows as an ornamental plant and its leaves are used as a dietary supplement in the treatment of diabetes mellitus. Recently, a number of researches have been carried out to evaluate the anti-diabetic potential of this plant. Besides, it has been proven to possess various pharmacological activities like hypolipidemic, diuretic, antioxidant, anti-microbial, anti-cancerous. Further, various phytochemical investigations reveal the presence of carbohydrates, triterpenoids, proteins, alkaloids, tannins, saponins, flavonoids, steroid, and appreciable amounts of trace elements. This work is an attempt to compile and explore the different pharmacological and phytochemical studies reported till date. PMID:24600198

  12. A review on Insulin plant (Costus igneus Nak)

    PubMed Central

    Hegde, Prakash K.; Rao, Harini A.; Rao, Prasanna N.

    2014-01-01

    Costus igneus Nak and Costus pictus D. Don, commonly known as Spiral flag, is a member of Costaceae and a newly introduced plant in India from South and Central America. It is a perennial, upright, spreading plant reaching about two feet tall, with spirally arranged leaves and attractive flowers. In southern India, it usually grows as an ornamental plant and its leaves are used as a dietary supplement in the treatment of diabetes mellitus. Recently, a number of researches have been carried out to evaluate the anti-diabetic potential of this plant. Besides, it has been proven to possess various pharmacological activities like hypolipidemic, diuretic, antioxidant, anti-microbial, anti-cancerous. Further, various phytochemical investigations reveal the presence of carbohydrates, triterpenoids, proteins, alkaloids, tannins, saponins, flavonoids, steroid, and appreciable amounts of trace elements. This work is an attempt to compile and explore the different pharmacological and phytochemical studies reported till date. PMID:24600198

  13. Bead and Process for Removing Dissolved Metal Contaminants

    SciTech Connect

    Summers, Bobby L., Jr.; Bennett, Karen L.; Foster, Scott A.

    2005-01-18

    A bead is provided which comprises or consists essentially of activated carbon immobilized by crosslinked poly (carboxylic acid) binder, sodium silicate binder, or polyamine binder. The bead is effective to remove metal and other ionic contaminants from dilute aqueous solutions. A method of making metal-ion sorbing beads is provided, comprising combining activated carbon, and binder solution (preferably in a pin mixer where it is whipped), forming wet beads, and heating and drying the beads. The binder solution is preferably poly(acrylic acid) and glycerol dissolved in water and the wet beads formed from such binder solution are preferably heated and crosslinked in a convection oven.

  14. Design of a Mechanical NaK Pump for Fission Space Power Systems

    NASA Technical Reports Server (NTRS)

    Mireles, Omar R.; Bradley, David; Godfroy, Thomas

    2010-01-01

    Alkali liquid metal cooled fission reactor concepts are under development for mid-range spaceflight power requirements. One such concept utilizes a sodium-potassium eutectic (NaK) as the primary loop working fluid. Traditionally, linear induction pumps have been used to provide the required flow and head conditions for liquid metal systems but can be limited in performance. This paper details the design, build, and check-out test of a mechanical NaK pump. The pump was designed to meet reactor cooling requirements using commercially available components modified for high temperature NaK service.

  15. Overview of processes affecting contaminant release from confined disposal facilities. Final report

    SciTech Connect

    Martin, J.L.; McCutcheon, S.C.

    1992-01-01

    Confined disposal facilities (CDFs) are widely used for the disposal of dredged material from Corps of Engineers maintenance dredging projects along the Atlantic and Gulf coasts and waterways and harbors in the Great Lakes. CDFs are a less common disposal alternative along the Pacific coast and inland river systems. When contaminated dredged material is placed in the CDF, there is a potential for contaminant mobilization and release from the CDF by a variety of physical, chemical, and biological processes. This report provides an overview of the processes affecting mobilization and release of contaminants from CDFs and the potential applicability of multimedia models for prediction of contaminant release. Processes affecting release from in-water CDFs are emphasized, although many of the processes discussed are applicable to nearshore and upland CDFs. Processes affecting contaminant release are complex, involving a variety of chemicals and operational and design considerations. Many of the important processes are reasonably well known. Laboratory column settling and elutriate techniques have been developed to estimate solids and contaminant concentration in water directly released during hydraulic disposal operations. Predictive techniques for other processes are not as available.

  16. In Situ Vitrification: Recent test results for a contaminated soil melting process

    SciTech Connect

    Buelt, J.L.; Timmerman, C.L.; Westsik, J.H. Jr.

    1988-06-01

    In Situ Vitrification (ISV) is being developed at Pacific Northwest Laboratory for the Department of Energy and other clients for the stabilization of soils and sludges contaminated with radioactive and hazardous chemical wastes. ISV is a process that immobilizes contaminated soil in place by converting it to a durable glass and crystalline product that is similar to obsidian. In June 1987, a large-scale test of the process was completed at a transuranic- contaminated soil site. This constituted the first full-scale demonstration of the ISV process at an actual site. This paper summarizes the preliminary results of this test and describes the processes' potential adaptation to radioactive and hazardous chemical waste contaminated soils. 10 refs., 10 figs.

  17. Contamination control in hybrid microelectronic modules. Part 3: Specifications for coating material and process controls

    NASA Technical Reports Server (NTRS)

    Himmel, R. P.

    1975-01-01

    Resin systems for coating hybrids prior to hermetic sealing are described. The resin systems are a flexible silicone junction resin system and a flexible cycloaliphatic epoxy resin system. The coatings are intended for application to the hybrid after all the chips have been assembled and wire bonded, but prior to hermetic sealing of the package. The purpose of the coating is to control particulate contamination by immobilizing particles and by passivating the hybrid. Recommended process controls for the purpose of minimizing contamination in hybrid microcircuit packages are given. Emphasis is placed on those critical hybrid processing steps in which contamination is most likely to occur.

  18. In situ vitrification: Test results for a contaminated soil-melting process

    SciTech Connect

    Buelt, J.L.; Timmerman, C.L.; Westsik, J.H. Jr.

    1989-10-01

    In situ vitrification (ISV) is being developed at Pacific Northwest Laboratory for the Department of Energy to stabilize soils and sludges that are contaminated with radioactive and hazardous chemical wastes. ISV is a process that immobilizes contaminated soil in place by converting it to a durable glass and crystalline product similar to obsidian and basalt. In June 1987, a large-scale test of the process was completed at a transuranic-contaminated soil site. The test constituted the first full-scale demonstration of ISV at an actual site. This paper summarizes the results of that test and describes the potential adaptation of the process to radioactive and hazardous chemical waste-contaminated soils. 15 refs., 9 figs., 3 tabs.

  19. Na and K Dependence of the Na/K Pump in Cystic Fibrosis Fibroblasts

    NASA Astrophysics Data System (ADS)

    Reznik, Vivian M.; Schneider, Jerry A.; Mendoza, Stanley A.

    1981-11-01

    The Na and K dependence of the Na/K pump was measured in skin fibroblasts from patients with cystic fibrosis and age/sex-matched controls. Under basal conditions, there was no difference between control and cystic fibrosis cells in protein per cell, intracellular Na and K content, or Na/K pump activity (measured as ouabain-sensitive 86Rb uptake). There was no difference in the Na dependence of the Na/K pump between cystic fibrosis cells and control cells. In cells from patients with cystic fibrosis, the Na/K pump had a significantly lower affinity for K (Km = 1.6 mM) when compared to normals (Km = 0.9 mM). This difference was demonstrated by using two independent experimental designs.

  20. Unit Process Wetlands for Removal of Trace Organic Contaminants and Pathogens from Municipal Wastewater Effluents

    PubMed Central

    Jasper, Justin T.; Nguyen, Mi T.; Jones, Zackary L.; Ismail, Niveen S.; Sedlak, David L.; Sharp, Jonathan O.; Luthy, Richard G.; Horne, Alex J.; Nelson, Kara L.

    2013-01-01

    Abstract Treatment wetlands have become an attractive option for the removal of nutrients from municipal wastewater effluents due to their low energy requirements and operational costs, as well as the ancillary benefits they provide, including creating aesthetically appealing spaces and wildlife habitats. Treatment wetlands also hold promise as a means of removing other wastewater-derived contaminants, such as trace organic contaminants and pathogens. However, concerns about variations in treatment efficacy of these pollutants, coupled with an incomplete mechanistic understanding of their removal in wetlands, hinder the widespread adoption of constructed wetlands for these two classes of contaminants. A better understanding is needed so that wetlands as a unit process can be designed for their removal, with individual wetland cells optimized for the removal of specific contaminants, and connected in series or integrated with other engineered or natural treatment processes. In this article, removal mechanisms of trace organic contaminants and pathogens are reviewed, including sorption and sedimentation, biotransformation and predation, photolysis and photoinactivation, and remaining knowledge gaps are identified. In addition, suggestions are provided for how these treatment mechanisms can be enhanced in commonly employed unit process wetland cells or how they might be harnessed in novel unit process cells. It is hoped that application of the unit process concept to a wider range of contaminants will lead to more widespread application of wetland treatment trains as components of urban water infrastructure in the United States and around the globe. PMID:23983451

  1. Electrochemical processes for in-situ treatment of contaminated soils. 1998 annual progress report

    SciTech Connect

    Huang, C.P.

    1998-06-01

    'This research project is to develop electrochemical processes for in-situ treatment of contaminated soils. Specifically, it is to study electrokinetic (EK) and electro-Fento (EF) processes and to integrate these processes for the treatment of soils containing mixed contaminants. The objectives are: (1) To study important parameters controlling the mobilization and the transport of selected organics and metals in soils by the electrokinetic (EK) process. Factors to be studied include field strength, pH, ionic strength, soil washing agents, types of organic and metal contaminants, and soil surface properties such as cation exchange capacity(CEC), soil organic content, soil moisture content, soil composition, and surface charge. (2) To study the important factors governing the oxidation of selected organic contaminants by the electro-Fenton (EF) process. Parameters such as pH, surface area and the configuration of working electrode, oxygen concentration, ferrous ion, and temperature that may affect the performance of the EF process will be investigated. (3) To understand the mechanism of the oxidation of selected organic contaminants by the electro-Fenton oxidation process.'

  2. Evidence for coordinate genetic control of Na,K pump density in erythrocytes and lymphocytes

    SciTech Connect

    DeLuise, M.; Flier, J.S.

    1985-08-01

    The erythrocyte is widely used as a model cell for studies of the Na,K pump in health and disease. However, little is known about the factors that control the number of Na,K pumps expressed on the erythrocytes of a given individual, nor about the extent to which erythrocytes can be used to validly assess the pump density on other cell types. In this report, the authors have compared the interindividual variance of Na,K pump density in erythrocytes of unrelated individuals to that seen with identical twins. Unlike unrelated individuals, in whom pump parameters, i.e., ouabain binding sites, /sup 86/Rb uptake, and cell Na concentration vary widely, identical twin pairs showed no significant intrapair variation for these values. Thus, a role for genetic factors is suggested. In addition, the authors established and validated a method for determining Na,K pump density and pump-mediated /sup 86/Rb uptake in human peripheral lymphocytes. Using this method, they show that whereas Na,K pump density differs markedly between erythrocytes (mean of 285 sites per cell) and lymphocytes (mean 40,600 sites per cell), there is a strong and highly significant correlation (r = 0.79, P less than 0.001) between the pump density in these cell types in any given individual. Taken together, these studies suggest that genetic factors are important determinants of Na,K pump expression, and that pump density appears to be coordinately regulated in two cell types in healthy individuals.

  3. Functional interaction of nicotinic acetylcholine receptors and Na+/K+ ATPase from Locusta migratoria manilensis (Meyen).

    PubMed

    Bao, Haibo; Sun, Huahua; Xiao, Youxin; Zhang, Yixi; Wang, Xin; Xu, Xiaoyong; Liu, Zewen; Fang, Jichao; Li, Zhong

    2015-01-01

    Associated proteins are important for the correct functioning of nicotinic acetylcholine receptors (nAChRs). In the present study, a neonicotinoid-agarose affinity column was used to isolate related proteins from a solubilized membrane preparation from the nervous system of Locusta migratoria manilensis (Meyen). 1530 peptides were identified and most of them were involved in the membranous structure, molecular interaction and cellular communication. Among these peptides, Na(+)/K(+) ATPase had the highest MASCOT score and were involved in the molecular interaction, which suggested that Na(+)/K(+) ATPase and nAChRs might have strong and stable interactions in insect central nervous system. In the present study, functional interactions between nAChRs and Na(+)/K(+) ATPase were examined by heterologous expression in Xenopus oocytes. The results showed that the activated nAChRs increased pump currents of Na(+)/K(+) ATPase, which did not require current flow through open nAChRs. In turn, Na(+)/K(+) ATPase significantly increased agonist sensitivities of nAChRs in a pump activity-independent manner and reduced the maximum current (Imax) of nAChRs. These findings provide novel insights concerning the functional interactions between insect nAChRs and Na(+)/K(+) ATPase. PMID:25743085

  4. Functional interaction of nicotinic acetylcholine receptors and Na+/K+ ATPase from Locusta migratoria manilensis (Meyen)

    PubMed Central

    Bao, Haibo; Sun, Huahua; Xiao, Youxin; Zhang, Yixi; Wang, Xin; Xu, Xiaoyong; Liu, Zewen; Fang, Jichao; Li, Zhong

    2015-01-01

    Associated proteins are important for the correct functioning of nicotinic acetylcholine receptors (nAChRs). In the present study, a neonicotinoid-agarose affinity column was used to isolate related proteins from a solubilized membrane preparation from the nervous system of Locusta migratoria manilensis (Meyen). 1530 peptides were identified and most of them were involved in the membranous structure, molecular interaction and cellular communication. Among these peptides, Na+/K+ ATPase had the highest MASCOT score and were involved in the molecular interaction, which suggested that Na+/K+ ATPase and nAChRs might have strong and stable interactions in insect central nervous system. In the present study, functional interactions between nAChRs and Na+/K+ ATPase were examined by heterologous expression in Xenopus oocytes. The results showed that the activated nAChRs increased pump currents of Na+/K+ ATPase, which did not require current flow through open nAChRs. In turn, Na+/K+ ATPase significantly increased agonist sensitivities of nAChRs in a pump activity-independent manner and reduced the maximum current (Imax) of nAChRs. These findings provide novel insights concerning the functional interactions between insect nAChRs and Na+/K+ ATPase. PMID:25743085

  5. Long-length contaminated equipment disposal process path document

    SciTech Connect

    McCormick, W.A.

    1998-09-30

    The first objective of the LLCE Process Path Document is to guide future users of this system on how to accomplish the cradle-to-grave process for the disposal of long-length equipment. Information will be provided describing the function and approach to each step in the process. Pertinent documentation, prerequisites, drawings, procedures, hardware, software, and key interfacing organizations will be identified. The second objective is related to the decision to lay up the program until funding is made available to complete it or until a need arises due to failure of an important component in a waste tank. To this end, the document will identify work remaining to be completed for each step of the process and open items or issues that remain to be resolved.

  6. [Evaluation of microbial contamination of linens in industrial laundry processes].

    PubMed

    Sanna, Adriana; Coroneo, Valentina; Dessì, Sandro; Brandas, Valeria

    2013-01-01

    Laundering linens and protecting them from microbiological recontamination are critical issues for the hotel and food industries and especially for hospitals. This study was performed to evaluate a sample of industrial laundries in Sardinia (Italy), to assess their compliance with national hygienic and sanitary regulations, along the complete laundering process. Study results indicate that industrial laundering processes are effective and that better awareness of staff who handle laundered textiles is required to reduce the risk of recontamination. PMID:23903035

  7. Radioactive contamination of the Balchug (Upper Yenisey) floodplain, Russia in relation to sedimentation processes and geomorphology.

    PubMed

    Linnik, V G; Brown, J E; Dowdall, M; Potapov, V N; Surkov, V V; Korobova, E M; Volosov, A G; Vakulovsky, S M; Tertyshnik, E G

    2005-03-01

    The radioactive contamination of a riverine floodplain, heavily influenced by discharges from Krasnoyarsk-26, has been studied with respect to sedimentation processes and the geomorphology of the Upper Yenisey floodplain. The study was effected by implementation of a regime of in situ observations and measurements, sampling, and the interpretation of satellite images. The results of the study indicate that on the Balchug Bypass Floodplain, radionuclide contamination is primarily influenced by the thickness of the deposited sediments, and the area can be considered as two depositional environments. The Balchug floodplain area was contaminated due to sedimentation of radionuclide-contaminated alluvium, whose depositional regime significantly changed after the construction of a hydroelectric power station in 1967. Contamination levels are lower on the upstream part of the floodplain where sediment depth is less than 0.2-0.3 m, and this contamination started to accumulate in 1967, while the downstream part of the floodplain, exhibiting deeper deposits, displays higher levels of radionuclide contamination because radionuclides began to deposit here in 1958 when the Krasnoyarsk-26 Mining and Chemical Combine (KMCC) commenced operation. Radionuclide contamination of the floodplain is also related to the elevation of the floodplain, higher regions of the floodplain typically having lower contamination than low-lying areas, which tend to be frequently inundated with sediments being deposited during such inundations. Local relief, its orientation, and vegetation cover have also combined to form sediment traps with significantly higher radionuclide contamination. Lithological analysis combined with radiometric assay indicates a total 137Cs floodplain inventory of 33.7 GBq. PMID:15740772

  8. Attached Bacterial Cell Contamination of Shell Egg Processing Facilities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sanitation is vital to providing safe, healthy food to consumers. Understanding the degree to which microorganisms persist on specific equipment or locations contributes to developing effective sanitation programs. Certain microbial populations may be used to determine areas within a processing pl...

  9. Altered erythrocyte Na-K pump in anorectic patients

    SciTech Connect

    Pasquali, R.; Strocchi, E.; Malini, P.; Casimirri, F.; Ambrosioni, E.; Melchionda, N.; Labo, G.

    1985-07-01

    The status of the erythrocyte sodium pump was evaluated in a group of patients suffering from anorexia nervosa and a group of healthy female control subjects. Anorectic patients showed significantly higher mean values of digoxin-binding sites/cell (ie, the number of Na-K-ATPase units) with respect to control subjects while no differences were found in the specific /sup 86/Rb uptake (which reflects the Na-K-ATPase activity) between the two groups. A significant correlation was found between relative weight and the number of Na-K-ATPase pump units (r = -0.66; P less than 0.0001). Anorectic patients showed lower serum T3 concentrations (71.3 +/- 53 ng/dL) with respect to control subjects (100.8 +/- 4.7 ng/dL; P less than 0.0005) and a significant negative correlation between T3 levels and the number of pump units (r = -0.52; P less than 0.003) was found. This study therefore shows that the erythrocyte Na-K pump may be altered in several anorectic patients. The authors suggest that this feature could be interrelated with the degree of underweight and/or malnutrition.

  10. INFLUENCE OF COUPLED PROCESSES ON CONTAMINANT FATE AND TRANSPORT IN SUBSURFACE ENVIRONMENTS

    SciTech Connect

    Jardine, Philip M

    2008-01-01

    The following chapter emphasizes subsurface environmental research investigations over the past 10 to 15 years that couple hydrological, geochemical, and biological processes as related to contaminant fate and transport. An attempt is made to focus on field-scale studies with possible reference to laboratory-scale endeavors. Much of the research discussed reflects investigations of the influence of coupled processes on the fate and transport of inorganic, radionuclide, and organic contaminants in subsurface environments as a result of natural processes or energy and weapons production endeavors that required waste disposal. The chapter provides on overview of the interaction between hydro-bio-geochemical processes in structured, heterogeneous subsurface environments and how these interactions control contaminant fate and transport, followed by experimental and numerical subsurface science research and case studies involving specific classes of inorganic and organic contaminants. Lastly, thought provoking insights are highlighted on why the study of subsurface coupled processes is paramount to understanding potential future contaminant fate and transport issues of global concern.

  11. Evaluation of processing factors for selected organic contaminants during virgin olive oil production: Distribution of BTEXS during olives processing.

    PubMed

    López-Blanco, Rafael; Gilbert-López, Bienvenida; Rojas-Jiménez, Rubén; Robles-Molina, José; Ramos-Martos, Natividad; García-Reyes, Juan F; Molina-Díaz, Antonio

    2016-05-15

    The presence of BTEXS (benzene, toluene, ethylbenzene, xylenes and styrene) in virgin olive oils can be attributed to environmental contamination, but also to biological processes during oil lipogenesis (styrene). In this work, the processing factor of BTEXS from olives to olive oil during its production was evaluated at lab-scale with an Abencor system. Benzene showed the lowest processing factor (15%), whereas toluene and xylenes showed an intermediate behavior (with 40-60% efficiency), and ethylbenzene and styrene were completely transferred (100%). In addition, an attempt to examine the contribution of potential sources to olives contamination with BTEXS was carried out for the first time. Two types of olives samples were classified according to their proximity to the contamination source (road). Although higher levels of BTEXS were found in samples close to roads, the concentrations were relatively low and do not constitute a major contribution to BTEXS usually detected in olive oil. PMID:26775971

  12. The human erythrocyte Cl-dependent Na-K cotransport system as a possible model for studying the action of loop diuretics.

    PubMed Central

    Ellory, J. C.; Stewart, G. W.

    1982-01-01

    1 The recent demonstration of the chloride-dependence of the red cell Na-K cotransport system suggests an analogy between this process and the active Cl- absorption in the ascending loop of Henle, which is the target transport system for loop diuretics. 2 Using red cell K influx, four known loop diuretics, six experimental frusemide analogues, two thiazides, two K-retaining diuretics and one organomercurial were compared for inhibitory potency on the red cell Na-K cotransport system. 3 Except for mersalyl, whose exact mode of action in the kidney is still in doubt, the inhibition of the red cell system by various loop diuretics was consistent with both published whole body diuretic data and isolated perfused tubule studies, while the system did not respond to the thiazides or the K-retaining diuretics. 4 It is concluded that the human red cell Na-K cotransport system is a possible valid model process on which to study the activity of loop diuretics. PMID:7074281

  13. Occurrence of rhodamine B contamination in capsicum caused by agricultural materials during the vegetation process.

    PubMed

    Gao, Wei; Wu, Naiying; Du, Jingjing; Zhou, Li; Lian, Yunhe; Wang, Lei; Liu, Dengshuai

    2016-08-15

    This paper reports on the environmental rhodamine B (RhB) contamination in capsicum caused by agricultural materials during the vegetation process. Ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was applied to detect 64 capsicum samples from China, Peru, India and Burma. Results demonstrated that RhB was found in all samples at low concentrations (0.11-0.98 μg/kg), indicating RhB contamination in capsicums is probably a ubiquitous phenomenon. In addition, studies into soils, roots, stems and leaves in Handan of Hebei province, China showed that the whole ecologic chain had been contaminated with RhB with the highest levels in leaves. The investigation into the agricultural environment in Handan of Hebei province and Korla of Xinjiang province, China demonstrated that the appearances of RhB contamination in the tested capsicums are mainly due to the agricultural materials contamination. The study verified that environmental contamination should be an important origin for the RhB contamination in capsicum fruits. PMID:27006220

  14. EVALUATION OF THE ADA TECHNOLOGIES' ELECTRO-DECON PROCESS TO REMOVE RADIOLOGICAL CONTAMINATION

    SciTech Connect

    Pao, Jenn-Hai; Demmer, Rick L.; Argyle, Mark D.; Veatch, Brad D.

    2003-02-27

    A surface decontamination system featuring the use of ADA's electrochemical process was tested and evaluated. The process can be flexibly deployed by using an electrolyte delivery system that has been demonstrated to be reliable and effective. Experimental results demonstrate the effectiveness of this system for the surface decontamination of radiologically contaminated stainless steel.

  15. 9 CFR 381.94 - Contamination with Microorganisms; process control verification criteria and testing; pathogen...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...; process control verification criteria and testing; pathogen reduction standards. 381.94 Section 381.94... § 381.94 Contamination with Microorganisms; process control verification criteria and testing; pathogen... been complied with and written notice of same has been provided to the establishment. (b)...

  16. 9 CFR 381.94 - Contamination with Microorganisms; process control verification criteria and testing; pathogen...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...; process control verification criteria and testing; pathogen reduction standards. 381.94 Section 381.94... § 381.94 Contamination with Microorganisms; process control verification criteria and testing; pathogen... been complied with and written notice of same has been provided to the establishment. (b)...

  17. High pressure processing as an intervention for raw virus-contaminated shellfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the past 7 years, the USDA ARS Seafood Safety Laboratory has evaluated the potential use of high pressure processing (HPP) as a processing strategy for virus-contaminated shellfish. HPP can inactivate hepatitis A virus, (HAV), the human norovirus surrogates feline calicivirus and murine norovi...

  18. Adaptive Image Processing Methods for Improving Contaminant Detection Accuracy on Poultry Carcasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract A real-time multispectral imaging system has demonstrated a science-based tool for fecal and ingesta contaminant detection during poultry processing. In order to implement this imaging system at commercial poultry processing industry, the false positives must be removed. For doi...

  19. REMOVAL OF PCBS FROM A CONTAMINATED SOIL USING CF-SYSTEMS SOLVENT EXTRACTION PROCESS

    EPA Science Inventory

    The US EPA's START team in cooperation with EPA's SITE program evaluated a pilot scale solvent extraction process developed by CF-Systems. This process uses liquified propane to extract organic contaminants from soils, sludges, and sediments. A pilot-scale evaluation was conducte...

  20. Contamination and uniformity control in plasma processing tools

    SciTech Connect

    Selwyn, G.; Brackbill, J.; Jones, M.; Winske, D.

    1996-10-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). We have collaborated with industry to build a laboratory to study plasma processing, a surface-cleaning technique that uses short-lived, gaseous reactants in place of chemical solvents. We have performed experiments and developed computer models to understand how complex substrate geometries affect plasma electrical properties and to demonstrate the feasibility of generating metastable molecular oxygen in a plasma.

  1. Leptin inhibits the Na(+)/K(+) ATPase in Caco-2 cells via PKC and p38MAPK.

    PubMed

    El-Zein, Ola; Usta, Julnar; El Moussawi, Layla; Kreydiyyeh, Sawsan Ibrahim

    2015-03-01

    We demonstrated previously an inhibitory effect of luminal leptin on glucose absorption in differentiated Caco-2 cells. Since this process is dependent on the Na(+) gradient established by the Na(+)/K(+)ATPase this work was undertaken to investigate if the ATPase is one of the hormone's targets. Fully differentiated Caco-2 cells were incubated with 10nM luminal leptin and the activity of the Na(+)/K(+) ATPase was assayed by measuring the amount of inorganic phosphate liberated. To elucidate the signaling pathway involved, the suspected mediators, namely PKC, p38MAPK, ERK and PI3K, were inhibited with specific pharmacological inhibitors and their implication was confirmed by determining changes in the protein expression of their active phosphorylated forms by Western blot analysis. Leptin reduced significantly the activity of the Na(+)/K(+) ATPase, by activating p38MAPK via inhibition of PKC, an upstream inhibitor of the kinase. ERK and PI3K are modulators of the pump and are not along the pathway activated by leptin but cross talk with it at the level of p38MAPK. PMID:25499980

  2. Lattice strain across Na-K interdiffusion fronts in alkali feldspar: an electron back-scatter diffraction study

    NASA Astrophysics Data System (ADS)

    Schäffer, Anne-Kathrin; Jäpel, Tom; Zaefferer, Stefan; Abart, Rainer; Rhede, Dieter

    2014-11-01

    Cation exchange experiments between gem quality sanidine and KCl melt produced chemical alteration of alkali feldspar starting at the grain surface and propagating inwards by highly anisotropic Na-K interdiffusion on the alkali sublattice. Diffusion fronts developing in b-direction are very sharp, while diffusion fronts within the a- c-plane are comparatively broad. Due to the composition dependence of the lattice parameters of alkali feldspar, the diffusion induced compositional heterogeneity induces coherency stress and elastic strain. Electron back-scatter diffraction combined with the cross-correlation technique was employed to determine the lattice strain distribution across the Na-K interdiffusion fronts in partially exchanged single crystals of alkali feldspar. The strain changes gradually across the broad fronts within the a- c-plane, with a successive extension primarily in a-direction conferring to the composition strain in unstressed alkali feldspar. In contrast, lattice strain characterised by pronounced extension in b-direction is localised at the sharp diffusion fronts parallel to b, followed by a slight expansion in a-direction in the orthoclase-rich rim. This strain pattern does not confer with the composition induced lattice strain in a stress-free alkali feldspar. It may rather be explained by the mechanical coupling of the exchanged surface layer and the mechanically strong substratum. The lattice distortion localised at the sharp diffusion front may have an influence on the diffusion process and appears to produce a self-sharpening feedback, leading to a local reduction of component mobilities.

  3. Effect of blocking the Na+/K+ ATPase on Ca2+ extrusion and light adaptation in mammalian retinal rods.

    PubMed Central

    Demontis, G C; Ratto, G M; Bisti, S; Cervetto, L

    1995-01-01

    Membrane current and light response were recorded from rods of monkey and guinea pig by means of suction electrodes. The correlation between adaptation and the Na+/K+ pump was investigated by measuring light-dependent changes in sensitivity with and without inhibition of Na+/K+ ATPase by strophanthidin. Strophanthidin was found to reduce the dark current, to slow the time course of the photoresponse, and to increase light sensitivity. At concentrations between 20 and 500 nM, the pump inhibitor suppressed in a reversible way the current re-activation occurring during prolonged illumination and modified the light-dependent decrease in sensitivity, which in control conditions approximates to a Weber-Fechner function. The effects of the pump inhibitor on the adaptive properties of rods are associated with an increased time constant of the membrane current attributed to the operation of the Na+:Ca2+,K+ exchanger. The effects of rapid application of the pump inhibitor on the current re-activation are consistent with the idea that significant changes in the internal sodium occur in rods of mammals during background illumination and that they play an important role in the process of light adaptation. PMID:8527658

  4. Selectivity of a Singly Permeating Ion in Nonselective NaK Channel: Combined QM and MD Based Investigations.

    PubMed

    Sadhu, Biswajit; Sundararajan, Mahesh; Bandyopadhyay, Tusar

    2015-10-01

    Ion channels, such as potassium channels are known to discriminate ions to achieve remarkable selective transportation of K(+) over Na(+) through the membrane. The recently reported NaK ion channel, on the contrary, seems to be an exception, as it is observed to permeate most of the group IA alkali metal cations and hence is suggested to be nonselective in nature. However, does that correspond to a complete annihilation of selectivity inside the selectivity filter (SF) of the channel? What is the origin of such nonselectivity/selectivity, if any? The present computational study is an extensive multiscale modeling approach to find the probable answers to these intriguing questions. Here, we have used density functional theory (DFT) based calculations using a realistic truncated model of SF from the crystal structures of the NaK ion channel to evaluate the binding of various alkali metal ions (Na(+), K(+) and Cs(+)), free from "contamination" due to the absence any other "rivalry" cations, in its different binding sites. Among all of the possible binding sites, a vestibule is noticed to be nonselective and seen to act as a probable binding site only in the presence of multiple ions. Binding sites S3 and S4 are found to be selective for K(+) and Na(+), respectively. As an important observation, we find that calculations on oversimplified models using an isolated ion binding site may lead to an erroneous selectivity trend as it neglects the synergetics of consecutive binding sites on the final outcome. Energy decomposition analysis revealed ion-dipole electrostatics as the major contributing interaction in metal-bound binding sites. Our investigations find that although NaK is permeable to monovalent alkali metal ions, strongly "site specific" selectivity does exist at the three well-defined noncontiguous binding sites of the SF. Different important physicomechanical parameters (such as ligating environment, synergistic influence of binding sites, and topological

  5. Long-term oil contamination increases deterministic assembly processes in soil microbes.

    PubMed

    Liang, Yuting; Zhang, Xu; Zhou, Jizhong; Li, Guanghe

    2015-07-01

    The mechanisms that drive microbial turnover in time and space have received considerable attention but remain unclear, especially for situations with anthropogenic perturbation. To understand the impact of long-term oil contamination on microbial spatial turnover, 100 soil samples were taken from five oil exploration fields located in different geographic regions across China. The microbial functional diversity was analyzed with a high-throughput functional gene array, GeoChip. Our results indicated that soil microbial α-diversity (richness and Shannon diversity index) decreased significantly with contamination. All contaminated and uncontaminated samples exhibited significant spatial autocorrelation between microbial community similarity and spatial distance, as described by a distance-decay relationship (DDR). However, long-term oil exposure flattened the slopes of the DDRs of all of the functional genes and each functional group involved in C/N/P/S cycling, particularly of those involved in contaminant degradation. The relative importance of deterministic and stochastic processes in microbial assembly was determined. The decrease in microbial spatial turnover with long-term oil contamination was coupled with an increase in the proportion of deterministic processes that structured microbial assembly based on null model analysis. The results indicated long-term oil contamination significantly affects soil microbial community spatial structure by acting as an environmental filter to decrease the regional differences distinguishing soil microbial communities. PMID:26485952

  6. Detection and identification of wild yeast contaminants of the industrial fuel ethanol fermentation process.

    PubMed

    Basílio, A C M; de Araújo, P R L; de Morais, J O F; da Silva Filho, E A; de Morais, M A; Simões, D A

    2008-04-01

    Monitoring for wild yeast contaminants is an essential component of the management of the industrial fuel ethanol manufacturing process. Here we describe the isolation and molecular identification of 24 yeast species present in bioethanol distilleries in northeast Brazil that use sugar cane juice or cane molasses as feeding substrate. Most of the yeast species could be identified readily from their unique amplification-specific polymerase chain reaction (PCR) fingerprint. Yeast of the species Dekkera bruxellensis, Candida tropicalis, Pichia galeiformis, as well as a species of Candida that belongs to the C. intermedia clade, were found to be involved in acute contamination episodes; the remaining 20 species were classified as adventitious. Additional physiologic data confirmed that the presence of these major contaminants cause decreased bioethanol yield. We conclude that PCR fingerprinting can be used in an industrial setting to monitor yeast population dynamics to early identify the presence of the most important contaminant yeasts. PMID:18188645

  7. Effects of natural attenuation processes on groundwater contamination caused by abandoned waste sites in Berlin

    NASA Astrophysics Data System (ADS)

    Kerndorff, Helmut; Kühn, Stephan; Minden, Thomas; Orlikowski, Dagmar; Struppe, Thomas

    2008-07-01

    The aim of this research project is to identify, characterize and quantify natural attenuation (NA) processes in groundwater affected by emissions of abandoned waste disposal sites in Berlin-Kladow/Gatow, Germany. It is part of the funding priority called KORA established by the Federal Ministry for Education and Research (BMBF) to explore the extent to which NA can be used for remedial purposes for varied forms of soil and groundwater contamination. Information on the emission behaviour of individual parameters is generated on the basis of hydrogeochemical comparison of 20 years old and new data. Using groundwater-modelling and CFC-analysis, information on the transport and retention of pollutants in groundwater is compiled. The microbial colonization of contaminated aquifers is characterized by molecular biological methods [polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE)] to differentiate between contaminated and not contaminated zones.

  8. Particle contamination control in plasma processing: Building-in reliability for semiconductor fabrication

    SciTech Connect

    Selwyn, G.S.

    1995-12-31

    Plasma processing is used for {approximately}35% of the process steps required for semiconductor manufacturing. Recent studies have shown that plasma processes create the greatest amount of contaminant dust of all the manufacturing steps required for device fabrication. Often, the level of dust in a plasma process tool exceeds the cleanroom by several orders of magnitude. Particulate contamination generated in a plasma tool can result in reliability problems as well as device failure. Inter-level wiring shorts different levels of metallization on a device is a common result of plasma particulate contamination. We have conducted a thorough study of the physics and chemistry involved in particulate formation and transport in plasma tools. In-situ laser light scattering (LLS) is used for real-time detection of the contaminant dust. The results of this work are highly surprising: all plasmas create dust; the dust can be formed by homogeneous as well as heterogeneous chemistry; this dust is charged and suspended in the plasma; additionally, it is transported to favored regions of the plasma, such as those regions immediately above wafers. Fortunately, this work has also led to a novel means of controlling and eliminating these unwanted contaminants: electrostatic {open_quotes}drainpipes{close_quotes} engineered into the electrode by means of specially designed grooves. These channel the suspended particles out of the plasma and into the pump port before they can fall onto the wafer.

  9. Contaminants of the bismuth phosphate process as signifiers of nuclear reprocessing history.

    SciTech Connect

    Schwantes, Jon M.; Sweet, Lucas E.

    2012-10-01

    Reagents used in spent nuclear fuel recycling impart unique contaminant patterns into the product stream of the process. Efforts are underway at Pacific Northwest National Laboratory to characterize and understand the relationship between these patterns and the process that created them. A main challenge to this effort, recycling processes that were employed at the Hanford site from 1944-1989 have been retired for decades. This precludes direct measurements of the contaminant patterns that propagate within product streams of these facilities. In the absence of any operating recycling facilities at Hanford, we have taken a multipronged approach to cataloging contaminants of U.S. reprocessing activities using: (1) historical records summarizing contaminants within the final Pu metal button product of these facilities; (2) samples of opportunity that represent intermediate products of these processes; and (3) lab-scale experiments and model simulations designed to replicate contaminant patterns at each stage of nuclear fuel reprocessing. This report provides a summary of the progress and results from Fiscal Year (April 1, 2010-September 30) 2011.

  10. Hybrid joule heating/electro-osmosis process for extracting contaminants from soil layers

    SciTech Connect

    Carrigan, Charles R.; Nitao, John J.

    2003-06-10

    Joule (ohmic) heating and electro-osmosis are combined in a hybrid process for removal of both water-soluble contaminants and non-aqueous phase liquids from contaminated, low-permeability soil formations that are saturated. Central to this hybrid process is the partial desaturation of the formation or layer using electro-osmosis to remove a portion of the pore fluids by induction of a ground water flow to extraction wells. Joule heating is then performed on a partially desaturated formation. The joule heating and electro-osmosis operations can be carried out simultaneously or sequentially if the desaturation by electro-osmosis occurs initially. Joule heating of the desaturated formation results in a very effective transfer or partitioning of liquid state contaminants to the vapor phase. The heating also substantially increases the vapor phase pressure in the porous formation. As a result, the contaminant laden vapor phase is forced out into soil layers of a higher permeability where other conventional removal processes, such as steam stripping or ground water extraction can be used to capture the contaminants. This hybrid process is more energy efficient than joule heating or steam stripping for cleaning low permeability formations and can share electrodes to minimize facility costs.

  11. D-glucose Stimulates the Na+/K+ Pump in Mouse Pancreatic Islet Cells

    PubMed Central

    Elmi, Adrian; Idahl, Lars-ÅKe; Sandström, Per-Erik

    2000-01-01

    To determine the effect of D-glucose on the β-cell Na+/K+ pump, 86Rb+ influx was studied in isolated, -cell-rich islets of Umeå-ob/ob mice in the absence or presence of lmM ouabain. D-glucose (20 mM) stimulated the ouabain-sensitive portion of 86Rb+ influx by 65%, whereas the ouabain-resistant portion was inhibited by 48%. The Na+/K+ ATPase activity in homogenates of islets of Umeå-ob/ob mice or normal mice was determined to search for direct effects of D-glucose. Thus, ouabain-sensitive ATP hydrolysis in islet homogenates was measured in the presence of different D-glucose concentrations. No effect of D-glucose (3–20 mM) was observed in either ob/ob or normal islets at the optimal Na+/K+ ratio for the enzyme (135 mM Na+ and 20 mM K+). Neither D-glucose (3–20 mM) nor L-glucose or 3-O-methyl-D-glucose (20 mM) affected the enzyme activity at a high Na+/K+ ratio (175 mM Na+ and 0.7mM K+). Diphenylhydantoin (150 μM) decreased the enzyme activity at optimal Na+/K+ ratio, whereas 50 μM of the drug had no effect. The results suggest that D-glucose induces a net stimulation the Na+/K+ pump of β-cells in intact islets and that D-glucose does not exert any direct effect on the Na+/K+ ATPase activity. PMID:11469399

  12. Reduced activity of SKC a and Na-K ATPase underlies the accelerated impairment of EDH-type relaxations in mesenteric arteries of aging spontaneously hypertensive rats.

    PubMed

    Kong, Billy W C; Man, Ricky Y K; Gao, Yuansheng; Vanhoutte, Paul M; Leung, Susan W S

    2015-06-01

    Aging is accompanied by endothelial dysfunction due to reduced bioavailability of nitric oxide (NO) and/or reduced endothelium-dependent hyperpolarizations (EDH). This study examines the hypothesis that hypertension aggravates the impairment of EDH-type relaxation due to aging. EDH-type relaxations were studied in superior mesenteric arteries isolated from Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats of 12, 36, 60, and 72 weeks of age. EDH-type relaxations in WKY were reduced with aging, and this was associated with an impairment of the function of small-conductance calcium-activated potassium channels (SKC a) and sodium-potassium ATPase (Na-K ATPase). EDH-type relaxation in SHR was smaller than that in WKY arteries, and further reduction occurred with aging. Pharmacological experiments suggested a reduced involvement of SKC a and Na-K ATPase and activation of adenosine monophosphate-activated protein kinase and silent information regulator T1 (sirtuin-1; SIRT1) in mesenteric arteries of 12-week-old SHR. These pharmacological findings suggest that in superior mesenteric arteries of the rat, the reduction in EDH-type relaxation occurs with aging and that such a reduction is exacerbated in hypertension. The latter exacerbation appears to involve proteins associated with the process of cellular senescence and is related to impaired function of SKC a and Na-K ATPase, a phenomenon that is also observed in mesenteric arteries of older normotensive rats. PMID:26171229

  13. RADIOLOGICAL CONTROLS FOR PLUTONIUM CONTAMINATED PROCESS EQUIPMENT REMOVAL FROM 232-Z CONTAMINATED WASTE RECOVERY PROCESS FACILITY AT THE PLUTONIUM FINSHING PLANT (PFP)

    SciTech Connect

    MINETTE, M.J.

    2007-05-30

    The 232-Z facility at Hanford's Plutonium Finishing Plant operated as a plutonium scrap incinerator for 11 years. Its mission was to recover residual plutonium through incinerating and/or leaching contaminated wastes and scrap material. Equipment failures, as well as spills, resulted in the release of radionuclides and other contamination to the building, along with small amounts to external soil. Based on the potential threat posed by the residual plutonium, the U.S. Department of Energy (DOE) issued an Action Memorandum to demolish Building 232-2, Comprehensive Environmental Response Compensation, and Liability Act (CERC1.A) Non-Time Critical Removal Action Memorandum for Removal of the 232-2 Waste Recovery Process Facility at the Plutonium Finishing Plant (04-AMCP-0486).

  14. Identification of risk factors for Campylobacter contamination levels on broiler carcasses during the slaughter process.

    PubMed

    Seliwiorstow, Tomasz; Baré, Julie; Berkvens, Dirk; Van Damme, Inge; Uyttendaele, Mieke; De Zutter, Lieven

    2016-06-01

    Campylobacter carcass contamination was quantified across the slaughter line during processing of Campylobacter positive batches. These quantitative data were combined together with information describing slaughterhouse and batch related characteristics in order to identify risk factors for Campylobacter contamination levels on broiler carcasses. The results revealed that Campylobacter counts are influenced by the contamination of incoming birds (both the initial external carcass contamination and the colonization level of caeca) and the duration of transport and holding time that can be linked with feed withdrawal period. In addition, technical aspects of the slaughter process such as a dump based unloading system, electrical stunning, lower scalding temperature, incorrect setting of plucking, vent cutter and evisceration machines were identified as risk factors associated with increased Campylobacter counts on processed carcasses. As such the study indicates possible improvements of the slaughter process that can result in better control of Campylobacter numbers under routine processing of Campylobacter positive batches without use of chemical or physical decontamination. Moreover, all investigated factors were existing variations of the routine processing practises and therefore proposed interventions are practically and economically achievable. PMID:27016637

  15. L. monocytogenes in a cheese processing facility: Learning from contamination scenarios over three years of sampling.

    PubMed

    Rückerl, I; Muhterem-Uyar, M; Muri-Klinger, S; Wagner, K-H; Wagner, M; Stessl, B

    2014-10-17

    The aim of this study was to analyze the changing patterns of Listeria monocytogenes contamination in a cheese processing facility manufacturing a wide range of ready-to-eat products. Characterization of L. monocytogenes isolates included genotyping by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Disinfectant-susceptibility tests and the assessment of L. monocytogenes survival in fresh cheese were also conducted. During the sampling period between 2010 and 2013, a total of 1284 environmental samples were investigated. Overall occurrence rates of Listeria spp. and L. monocytogenes were 21.9% and 19.5%, respectively. Identical L. monocytogenes genotypes were found in the food processing environment (FPE), raw materials and in products. Interventions after the sampling events changed contamination scenarios substantially. The high diversity of globally, widely distributed L. monocytogenes genotypes was reduced by identifying the major sources of contamination. Although susceptible to a broad range of disinfectants and cleaners, one dominant L. monocytogenes sequence type (ST) 5 could not be eradicated from drains and floors. Significantly, intense humidity and steam could be observed in all rooms and water residues were visible on floors due to increased cleaning strategies. This could explain the high L. monocytogenes contamination of the FPE (drains, shoes and floors) throughout the study (15.8%). The outcome of a challenge experiment in fresh cheese showed that L. monocytogenes could survive after 14days of storage at insufficient cooling temperatures (8 and 16°C). All efforts to reduce L. monocytogenes environmental contamination eventually led to a transition from dynamic to stable contamination scenarios. Consequently, implementation of systematic environmental monitoring via in-house systems should either aim for total avoidance of FPE colonization, or emphasize a first reduction of L. monocytogenes to sites where

  16. Synchronization modulation increases transepithelial potentials in MDCK monolayers through Na/K pumps.

    PubMed

    Tran, Vu; Zhang, Xiaodong; Cao, Lin; Li, Hanqing; Lee, Benjamin; So, Michelle; Sun, Yaohui; Chen, Wei; Zhao, Min

    2013-01-01

    Transepithelial potential (TEP) is the voltage across a polarized epithelium. In epithelia that have active transport functions, the force for transmembrane flux of an ion is dictated by the electrochemical gradient in which TEP plays an essential role. In epithelial injury, disruption of the epithelial barrier collapses the TEP at the wound edge, resulting in the establishment of an endogenous wound electric field (∼100 mV/mm) that is directed towards the center of the wound. This endogenous electric field is implicated to enhance wound healing by guiding cell migration. We thus seek techniques to enhance the TEP, which may increase the wound electric fields and enhance wound healing. We report a novel technique, termed synchronization modulation (SM) using a train of electric pulses to synchronize the Na/K pump activity, and then modulating the pumping cycles to increase the efficiency of the Na/K pumps. Kidney epithelial monolayers (MDCK cells) maintain a stable TEP and transepithelial resistance (TER). SM significantly increased TEP over four fold. Either ouabain or digoxin, which block Na/K pump, abolished SM-induced TEP increases. In addition to the pump activity, basolateral distribution of Na/K pumps is essential for an increase in TEP. Our study for the first time developed an electrical approach to significantly increase the TEP. This technique targeting the Na/K pump may be used to modulate TEP, and may have implication in wound healing and in diseases where TEP needs to be modulated. PMID:23585907

  17. Mobilisation processes responsible for iron and manganese contamination of groundwater in Central Adriatic Italy.

    PubMed

    Palmucci, William; Rusi, Sergio; Di Curzio, Diego

    2016-06-01

    Iron and manganese are two of the most common contaminants that exceed the threshold imposed by international and national legislation. When these contamination occurs in groundwater, the use of the water resource is forbidden for any purposes. Several studies investigated these two metals in groundwater, but research focused in the Central Adriatic area are still lacking. Thus, the objective of this study is to identify the origin of Fe and Mn contamination in groundwater and the hydrogeochemical processes that can enrich aquifers with these metals. This work is based on hydrogeochemical and multivariate statistical analysis of analytical results undertaken on soils and groundwater. Fe and Mn contamination are widespread in the alluvial aquifers, and their distribution is regulated by local conditions (i.e. long residence time, presence of peat or organic-rich fine sediments or anthropic pollution) that control redox processes in the aquifers and favour the mobilisation of these two metals in groundwater. The concentration of iron and manganese identified within soil indicates that the latter are a concrete source of the two metals. Anthropic impact on Fe and Mn contamination of groundwater is not related to agricultural activities, but on the contrary, the contribution of hydrocarbons (e.g. spills) is evident. PMID:26948970

  18. On-farm and postharvest processing sources of bacterial contamination to melon rinds.

    PubMed

    Gagliardi, J V; Millner, P D; Lester, G; Ingram, D

    2003-01-01

    Multistate and international foodborne illness outbreaks, particularly involving cantaloupe and often involving rare Salmonella spp., have increased dramatically over the past 13 years. This study assessed the sources and extent of melon rind contamination in production fields and at processing and packing facilities. In the spring of 1999, cantaloupe (Cucumis melo L. [reticulatus group] cv. Cruiser) sampled from two sites in the Rio Grande River Valley showed that postharvest-processed melon rinds often had greater plate counts of bacterial contaminants than field-fresh melons. Cantaloupe in the field had 2.5 to 3.5 log CFU g(-1) rind total coliforms by aerobic plate counts, whereas washed melons had 4.0 to 5.0 log CFU g(-1). In the fall of 1999, coliforms on honeydew melons (C. melo [inodorous group] cv. Honey Brew) ranged from 2.6 to 3.7 log CFU g(-1) after processing, and total and fecal coliforms and enterococci never fell below 2.5 log CFU g(-1). A hydrocooler at another site contaminated cantaloupe rinds with up to 3.4 log CFU g(-1) total and fecal enterococci; a secondary rinse with chlorinated water incompletely removed these bacteria. Sources of coliforms and enterococci were at high levels in melon production soils, especially in furrows that were flood irrigated, in standing water at one field, and in irrigation water at both sites. At one processing facility, wash water pumped from the Rio Grande River may not have been sufficiently disinfected prior to use. Because soil, irrigation water, and process water were potential sources of bacterial contamination, monitoring and management on-farm and at processing and packing facilities should focus on water quality as an important control point for growers and packers to reduce bacterial contamination on melon rinds. PMID:12540185

  19. MOLECULAR-LEVEL PROCESS GOVERNING THE INTERACTION OF CONTAMINANTS WITH IRON AND MANGANESE OXIDES

    EPA Science Inventory

    Many of the inorganic and organic contaminants present in sediments at DOE sites can bealtered or destroyed by reduction and oxidation (redox) reactions occurring at mineral surfaces. A fundamental understanding of such redox processes provided by molecular-level studies on stru...

  20. In situ treatment of mixed contaminants in groundwater: Review of candidate processes

    SciTech Connect

    Korte, N.E.; Siegrist, R.L.; Ally, M.

    1994-10-01

    This document describes the screening and preliminary evaluation of candidate treatment for use in treating mixed contaminants volatile organic compounds (VOCs) and radionuclides in groundwater. Treating mixed contaminants presents unusual difficulties. Typically, VOCs are the most abundant contaminants, but the presence of radionuclides results in additional health concerns that must be addressed, usually by a treatment approach different from that used for VOCs. Furthermore, the presence of radionuclides may yield mixed solid wastes if the VOCs are treated by conventional means. These issues were specifically addressed in the evaluation of candidate treatment processes for testing in this program. Moreover, because no research or early development of a particular process would be performed, the technology review also focused on technologies that could be readily adapted and integrated for use with mixed contaminants. The objective is to couple emerging or available processes into treatment modules for use in situ. The three year project, to be completed in September 1996, includes a full-scale field demonstration. The findings reported in this document encompass all activities through the treatment process evaluations.

  1. CONTAMINANT-ORGANIC COMPLEXES: THEIR STRUCTURE AND ENERGETICS IN SURFACE DECONTAMINATION PROCESSES

    EPA Science Inventory

    The current debate over possible decontamination processes for U.S. Department of Energy (DOE) facilities is centered on disparate decontamination problems, but the key contaminants (uranium [U], plutonium [Pu], and neptunium [Np]) are universally important. There is no single d...

  2. NATURAL ARSENIC CONTAMINATION OF HOLOCENE ALLUVIAL AQUIFERS BY LINKED TECTONIC, WEATHERING, AND MICROBIAL PROCESSES

    EPA Science Inventory

    Linked tectonic, geochemical, and biologic processes lead to natural arsenic contamination of groundwater in Holocene alluvial aquifers, which are the main threat to human health around the world. These groundwaters are commonly found a long distance from their ultimate source of...

  3. Research of polishing process to control the iron contamination on the magnetorheological finished KDP crystal surface.

    PubMed

    Chen, Shaoshan; Li, Shengyi; Peng, Xiaoqiang; Hu, Hao; Tie, Guipeng

    2015-02-20

    A new nonaqueous and abrasive-free magnetorheological finishing (MRF) method is adopted for processing a KDP crystal. MRF polishing is easy to result in the embedding of carbonyl iron (CI) powders; meanwhile, Fe contamination on the KDP crystal surface will affect the laser induced damage threshold seriously. This paper puts forward an appropriate MRF polishing process to avoid the embedding. Polishing results show that the embedding of CI powders can be avoided by controlling the polishing parameters. Furthermore, on the KDP crystal surface, magnetorheological fluids residua inevitably exist after polishing and in which the Fe contamination cannot be removed completely by initial ultrasonic cleaning. To solve this problem, a kind of ion beam figuring (IBF) polishing is introduced to remove the impurity layer. Then the content of Fe element contamination and the depth of impurity elements are measured by time of flight secondary ion mass spectrometry. The measurement results show that there are no CI powders embedding in the MRF polished surface and no Fe contamination after the IBF polishing process, respectively. That verifies the feasibility of MRF polishing-IBF polishing (cleaning) for processing a KDP crystal. PMID:25968216

  4. EPA Treatability Database Digs Deep for Data on Drinking Water Contaminants and Treatment Processes

    EPA Science Inventory

    The TDB is an interactive database that was initially developed in 2006-2007. The TDB currently contains more than 60 regulated and unregulated contaminants and 28 treatment processes that are known to be effective and are commonly employed at drinking water utilities. TDB lite...

  5. MICROBIAL PROCESSES AFFECTING MONITORED NATURAL ATTENUATION OF CONTAMINANTS IN THE SUBSURFACE

    EPA Science Inventory

    Among the alternatives considered for the remediation of soil and ground water at hazardous wastes sites are the use of natural processes to reduce or remove the contaminants of concern. Under favorable conditions, the use of natural attenuation can result in significant cost sa...

  6. Rapid evolution of redox processes in a petroleum hydrocarbon-contaminated aquifer

    USGS Publications Warehouse

    Chapelle, F.H.; Bradley, P.M.; Lovley, D.R.; O'Neill, K.; Landmeyer, J.E.

    2002-01-01

    Ground water chemistry data collected over a six-year period show that the distribution of contaminants and redox processes in a shallow petroleum hydrocarbon-contaminated aquifer has changed rapidly over time. Shortly after a gasoline release occurred in 1990, high concentrations of benzene were present near the contaminant source area. In this contaminated zone, dissolved oxygen in ground water was depleted, and by 1994 Fe(III) reduction and sulfate reduction were the predominant terminal electron accepting processes. Significantly, dissolved methane was below measurable levels in 1994, indicating the absence of significant methanogenesis. By 1996, however, depletion of solid-phase Fe(III)-oxyhydroxides in aquifer sediments and depletion of dissolved sulfate in ground water resulted in the onset of methanogenesis. Between 1996 and 2000, water-chemistry data indicated that methanogenic metabolism became increasingly prevalent. Molecular analysis of 16S-rDNA extracted from sediments shows the presence of a more diverse methanogenic community inside as opposed to outside the plume core, and is consistent with water-chemistry data indicating a shift toward methanogenesis over time. This rapid evolution of redox processes reflects several factors including the large amounts of contaminants, relatively rapid ground water flow (???0.3 m/day [???1 foot/day]), and low concentrations of microbially reducible Fe(III) oxyhydroxides (???1 ??mol/g) initially present in aquifer sediments. These results illustrate that, under certain hydrologic conditions, redox conditions in petroleum hydrocarbon-contaminated aquifers can change rapidly in time and space, and that the availability of solid-phase Fe(III)-oxyhydroxides affects this rate of change.

  7. A complete remediation process for a uranium-contaminated site and application to other sites

    SciTech Connect

    Mason, C.F.V.; Lu, N.; Kitten, H.D.; Williams, M.; Turney, W.R.J.R.

    1998-12-31

    During the summer of 1996 the authors were able to test, at the pilot scale, the concept of leaching uranium (U) from contaminated soils. The results of this pilot scale operation showed that the system they previously had developed at the laboratory scale is applicable at the pilot scale. The paper discusses these results, together with laboratory scale results using soil from the Fernald Environmental Management Project (FEMP), Ohio. These FEMP results show how, with suitable adaptations, the process is widely applicable to other sites. The purpose of this paper is to describe results that demonstrate remediation of uranium-contaminated soils may be accomplished through a leach scheme using sodium bicarbonate.

  8. High-efficiency localization of Na+-K+ ATPases on the cytoplasmic side by direct stochastic optical reconstruction microscopy

    NASA Astrophysics Data System (ADS)

    Wu, Jiazhen; Gao, Jing; Qi, Miao; Wang, Jianzhong; Cai, Mingjun; Liu, Shuheng; Hao, Xian; Jiang, Junguang; Wang, Hongda

    2013-11-01

    We describe a concise and effective strategy towards precisely mapping Na+-K+ ATPases on the cytoplasmic side of cell membranes by direct stochastic optical reconstruction microscopy (dSTORM). We found that most Na+-K+ ATPases are localized in different sizes of clusters on human red blood cell (hRBC) membranes, revealed by Ripley's K-function analysis. Further evidence that cholesterol depletion causes the dispersion of Na+-K+ ATPase clusters indicates that such clusters could be localized in cholesterol-enriched domains. Our results suggest that Na+-K+ ATPases might aggregate within the lipid rafts to fulfill their functions.We describe a concise and effective strategy towards precisely mapping Na+-K+ ATPases on the cytoplasmic side of cell membranes by direct stochastic optical reconstruction microscopy (dSTORM). We found that most Na+-K+ ATPases are localized in different sizes of clusters on human red blood cell (hRBC) membranes, revealed by Ripley's K-function analysis. Further evidence that cholesterol depletion causes the dispersion of Na+-K+ ATPase clusters indicates that such clusters could be localized in cholesterol-enriched domains. Our results suggest that Na+-K+ ATPases might aggregate within the lipid rafts to fulfill their functions. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03665k

  9. Cleaning and sanitation of Salmonella-contaminated peanut butter processing equipment.

    PubMed

    Grasso, Elizabeth M; Grove, Stephen F; Halik, Lindsay A; Arritt, Fletcher; Keller, Susanne E

    2015-04-01

    Microbial contamination of peanut butter by Salmonella poses a significant health risk as Salmonella may remain viable throughout the product shelf life. Effective cleaning and sanitation of processing lines are essential for preventing cross-contamination. The objective of this study was to evaluate the efficacy of a cleaning and sanitation procedure involving hot oil and 60% isopropanol, ± quaternary ammonium compounds, to decontaminate pilot-scale processing equipment harboring Salmonella. Peanut butter inoculated with a cocktail of four Salmonella serovars (∼ 7 log CFU/g) was used to contaminate the equipment (∼ 75 L). The system was then emptied of peanut butter and treated with hot oil (90 °C) for 2 h followed by sanitizer for 1 h. Microbial analysis of food-contact surfaces (7 locations), peanut butter, and oil were conducted. Oil contained ∼ 3.2 log CFU/mL on both trypticase soy agar with yeast extract (TSAYE) and xylose lysine deoxycholate (XLD), indicating hot oil alone was not sufficient to inactivate Salmonella. Environmental sampling found 0.25-1.12 log CFU/cm(2) remaining on processing equipment. After the isopropanol sanitation (± quaternary ammonium compounds), no Salmonella was detected in environmental samples on XLD (<0.16 log CFU/cm(2)). These data suggest that a two-step hot oil clean and isopropanol sanitization treatment may eliminate pathogenic Salmonella from contaminated equipment. PMID:25475272

  10. Decontamination and size reduction of plutonium contaminated process exhaust ductwork and glove boxes

    SciTech Connect

    LaFrate, P.; Elliott, J.; Valasquez, M.

    1996-11-15

    The Los Alamos National Laboratory (LANL) Decommissioning Program has decontaminated and demolished two filter plenum buildings at Technical Area 21 (TA-21). During the project a former hot cell was retrofitted to perform decontamination and size reduction of highly Pu contaminated process exhaust (1,100 ft) and gloveboxes. Pu-238/239 concentrations were as high a 1 Ci per linear foot and averaged approximately 1 mCi/ft. The Project decontamination objective was to reduce the plutonium contamination on surfaces below transuranic levels. If possible, metal surfaces were decontaminated further to meet Science and Ecology Group (SEG) waste classification guidelines to enable the metal to be recycled at their facility in oak Ridge, Tennessee. Project surface contamination acceptance criteria for low-level radioactive waste (LLRW), transuranic waste, and SEG waste acceptance criteria will be presented. Ninety percent of all radioactive waste for the project was characterized as LLRW. Twenty percent of this material was shipped to SEG. Process exhaust and glove boxes were brought to the project decontamination area, an old hot cell in Building 4 North. This paper focuses on process exhaust and glovebox decontamination methodology, size reduction techniques, waste characterization, airborne contamination monitoring, engineering controls, worker protection, lessons learned, and waste minimization. Decontamination objectives are discussed in detail.

  11. Ultrasonic process for remediation of organics-contaminated groundwater/wastewater

    SciTech Connect

    Wu, J.M.; Peters, R.W.

    1995-07-01

    A technology is being developed that employs ultrasonic-wave energy for remediation of groundwater/wastewater contaminated with volatile organic compounds such as carbon tetrachloride (CCl{sub 4}) and trichloroethylene (TCE). This paper presents the updated results of a laboratory investigation of ultrasonic groundwater remediation using synthetic groundwaters prepared with laboratory deionized water. Key process parameters investigated included steady-state temperature, contaminant concentration, solution pH, sonication time, and intensity of the applied ultrasonics-wave energy. High destruction efficiencies of the target contaminants were achieved, and the sonication time required for a given degree of destruction decreased with increasing intensity of the applied ultrasonic energy. The sonication time can be further reduced by adding a chemical oxidant such as hydrogen peroxide.

  12. Distribution of terminal electron-accepting processes in an aquifer having multiple contaminant sources

    USGS Publications Warehouse

    McMahon, P.B.; Bruce, B.W.

    1997-01-01

    Concentrations of electron acceptors, electron donors, and H2 in groundwater were measured to determine the distribution of terminal electron-accepting processes (TEAPs) in an alluvial aquifer having multiple contaminant sources. Upgradient contaminant sources included two separate hydrocarbon point sources, one of which contained the fuel oxygenate methyl tertbutyl ether (MTBE). Infiltrating river water was a source of dissolved NO31 SO4 and organic carbon (DOC) to the downgradient part of the aquifer. Groundwater downgradient from the MTBE source had larger concentrations of electron acceptors (dissolved O2 and SO4) and smaller concentrations of TEAP end products (dissolved inorganic C, Fe2+ and CH4) than groundwater downgradient from the other hydrocarbon source, suggesting that MTBE was not as suitable for supporting TEAPs as the other hydrocarbons. Measurements of dissolved H2 indicated that SO4 reduction predominated in the aquifer during a period of high water levels in the aquifer and river. The predominant TEAP shifted to Fe3+ reduction in upgradient areas after water levels receded but remained SO4 reducing downgradient near the river. This distribution of TEAPs is the opposite of what is commonly observed in aquifers having a single contaminant point source and probably reflects the input of Dec and SO4 to the aquifer from the river. Results of this study indicate that the distribution of TEAPs in aquifers having multiple contaminant sources depends on the composition and location of the contaminants and on the availability of electron acceptors.

  13. Evaluation of electrochemical processes for the removal of several target aromatic hydrocarbons from petroleum contaminated water.

    PubMed

    Alsalka, Yamen; Karabet, François; Hashem, Shahir

    2011-03-01

    Ground and surface water contamination resulting from the leakage of crude oil and refined petroleum products is a serious and growing environmental problem throughout the world. Consequently, a study of the use of electrochemical treatment in the clean-up was undertaken with the aim of reducing the water contamination by aromatic pollutants to more acceptable levels. In the experiments described, water contamination by refined petroleum products was simulated under laboratory conditions. Electrochemical treatment, using aluminium electrodes, has been optimised by full factorial design and surface response analysis in term of BTEX and PAHs removal and energy consumption. The optimal conditions of pH, current density, electrolysis time, electrolyte type, and electrolyte concentration have then been applied in the treatment of real water samples which were monitored as petroleum contaminated samples. Treatment results have shown that electrochemical methods could achieve the concentration of these pollutants to undetectable levels in particular groundwater and surface water, hence, they can be highly effective in the remediation of water contaminated by aromatic hydrocarbons, and the use of these processes is therefore recommended. PMID:21243149

  14. Activating Na+-K+ ATPase: a potential cardioprotective therapy during early hemorrhagic shock.

    PubMed

    Li, Weijing; Wang, Xuanlin; He, Min; Wang, Chunyan; Qiao, Zhixin; Wang, Qingjun; Ren, Suping; Yu, Qun

    2014-12-01

    Cell volume and resting potential are heavily affected by the activity of Na+-K+ ATPase (NKA, Na+-K+ pump), an essential membrane protein that regulates plasma K+ and Na+ levels. It is generally accepted that the ineffective perfusion of body tissues inhibits NKA activity and that NKA activity and heart failure are closely related. Recently, research has proven that the activation of NKA provides significant cardioprotection against ischemic injury. Based on these data, we propose that NKA stimulation could attenuate the development of heart arrhythmia during the early phase of hemorrhagic shock. PMID:25459134

  15. NaK Variable Conductance Heat Pipe for Radioisotope Stirling Systems

    NASA Technical Reports Server (NTRS)

    Tarau, Calin; Anderson, William G.; Walker, Kara

    2008-01-01

    In a Stirling radioisotope power system, heat must continually be removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides most of this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending use of that convertor for the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) was designed to allow multiple stops and restarts of the Stirling convertor. In the design of the VCHP for the Advanced Stirling Radioisotope Generator, the VCHP reservoir temperature can vary between 40 and 120 C. While sodium, potassium, or cesium could be used as the working fluid, their melting temperatures are above the minimum reservoir temperature, allowing working fluid to freeze in the reservoir. In contrast, the melting point of NaK is -12 C, so NaK can't freeze in the reservoir. One potential problem with NaK as a working fluid is that previous tests with NaK heat pipes have shown that NaK heat pipes can develop temperature non-uniformities in the evaporator due to NaK's binary composition. A NaK heat pipe was fabricated to measure the temperature non-uniformities in a scale model of the VCHP for the Stirling Radioisotope system. The temperature profiles in the evaporator and condenser were measured as a function of operating temperature and power. The largest delta T across the condenser was 2S C. However, the condenser delta T decreased to 16 C for the 775 C vapor temperature at the highest heat flux applied, 7.21 W/ square cm. This decrease with increasing heat flux was caused by the increased mixing of the sodium and potassium in the vapor. This temperature differential is similar to the temperature variation in this ASRG heat transfer interface without a heat pipe, so NaK can be used as the VCHP working fluid.

  16. Contamination patterns of Listeria monocytogenes in cold-smoked pork processing.

    PubMed

    Bērziņš, Aivars; Hellström, Sanna; Siliņš, Indulis; Korkeala, Hannu

    2010-11-01

    Contamination patterns of Listeria monocytogenes were studied in a cold-smoked pork processing plant to identify the sources and possible reasons for the contamination. Environmental sampling combined with pulsed-field gel electrophoresis (PFGE) subtyping and serotyping were applied to investigate the genetic diversity of L. monocytogenes in the plant environment and ready-to-eat (RTE) cold-smoked pork products. A total of 183 samples were collected for contamination analyses, including samples of the product at different stages during manufacture (n = 136) and environmental samples (n = 47) in 2009. L. monocytogenes isolates, previously recovered from 73 RTE cold-smoked pork samples and collected from the same meat processing plant in 2004, were included in this study. The brining machine and personnel working with brining procedures were the most contaminated places with L. monocytogenes. The overall prevalence of L. monocytogenes in raw pork (18%) increased to 60% after the brining injections. The brining machine harbored six different PFGE types belonging to serotypes 1/2a, 1/2c, 4b, and 4d, which were found on the feeding teeth, smooth surfaces, and spaces of the machine, thus potentially facilitating dissemination of L. monocytogenes contamination. Two PFGE types (2 and 8) belonging to serotypes 1/2a and 1/2c were recovered from RTE cold-smoked pork collected in 2004, and from surfaces of the brining machine sampled in 2009, and may indicate the presence of persistent L. monocytogenes strains in the plant. Due to poor hygiene design, removal of the brining machine from the production of cold-smoked meat products should be considered to reduce L. monocytogenes contamination in the finished products. PMID:21219726

  17. Process for removal of ammonia and acid gases from contaminated waters

    DOEpatents

    King, C.J.; Mackenzie, P.D.

    1982-09-03

    Contaminating basic gases, i.e., ammonia and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with stream, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

  18. Process for removal of ammonia and acid gases from contaminated waters

    DOEpatents

    King, C. Judson; MacKenzie, Patricia D.

    1985-01-01

    Contaminating basic gases, i.e., ammonia, and acid gases, e.g., carbon dioxide, are removed from process waters or waste waters in a combined extraction and stripping process. Ammonia in the form of ammonium ion is extracted by an immiscible organic phase comprising a liquid cation exchange component, especially an organic phosphoric acid derivative, and preferably di-2-ethyl hexyl phosphoric acid, dissolved in an alkyl hydrocarbon, aryl hydrocarbon, higher alcohol, oxygenated hydrocarbon, halogenated hydrocarbon, and mixtures thereof. Concurrently, the acidic gaseous contaminants are stripped from the process or waste waters by stripping with steam, air, nitrogen, or the like. The liquid cation exchange component has the ammonia stripped therefrom by heating, and the component may be recycled to extract additional amounts of ammonia.

  19. [Contamination with genetically modified maize MON863 of processed foods on the market].

    PubMed

    Ohgiya, Yoko; Sakai, Masaaki; Miyashita, Taeko; Yano, Koichi

    2009-06-01

    Genetically modified maize MON863 (MON863), which has passed a safety examination in Japan, is commercially cultivated in the United States as a food and a resource for fuel. Maize is an anemophilous flower, which easily hybridizes. However, an official method for quantifying the content of MON863 has not been provided yet in Japan. We here examined MON863 contamination in maize-processed foods that had no labeling indicating of the use of genetically modified maize.From March 2006 to July 2008, we purchased 20 frozen maize products, 8 maize powder products, 7 canned maize products and 4 other maize processed foods. Three primer pairs named MON 863 primer, MON863-1, and M3/M4 for MON863-specific integrated cassette were used for qualitative polymerase chain reaction (PCR). A primer pair "SSIIb-3" for starch synthase gene was used to confirm the quality of extracted DNA. The starch synthase gene was detected in all samples. In qualitative tests, the MON863-specific fragments were detected in 7 (18%) maize powder products out of the 39 processed foods with all the three primer pairs.We concluded that various maize processed foods on the market were contaminated with MON863. It is important to accumulate further information on MON863 contamination in maize-processed foods that have no label indication of the use of genetically modified maize. PMID:19602862

  20. Evaluation, modelling and optimization of the cleaning process of contaminated plastic food refillables.

    PubMed

    Devlieghere, F; De Meulenaer, B; Sekitoleko, P; Estrella Garcia, A A; Huyghebaert, A

    1997-01-01

    In this study several types of bottle materials (glass, PET (polyethylene terephthalate), PC (polycarbonate), HDPE (high density polyethylene), PP (polypropylene) and PVC (polyvinyl chloride)) were evaluated in order to be used as food refillables, comparing the residual chemical contamination after classical caustic washing. Bottles were contaminated with model chemicals (chloroxylenol and d-limonene) and caustic washed with varied process parameters using a simulated laboratory-scale washing procedure. After washing, the chemical-contaminated bottles were filled with water and stored for 28 days at 37 degrees C. The concentrations of the model chemicals in the water after storage were taken as a measure of chemical contamination. The influence of the cleaning parameters (temperature, caustic and commercial additive concentration) was studied using response surface methodology. Washing temperature showed a significant influence on the removal of absorbed chemicals from surfaces compared with the effect of the caustic and especially the additive concentration. Optimization of caustic cleaning for the cleaning process in question led to better cleaning effectiveness, although none of the different washing conditions were able to remove all absorbed chemicals out of the polymeric resins. Commercially available plastic refillables (PET and PC) showed the best chemical rinsability. Glass bottles, however, had in every case the best rinsing characteristics. PMID:9373531

  1. Contamination Control and Hardware Processing Solutions at Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Burns, DeWitt H.; Hampton, Tammy; Huey, LaQuieta; Mitchell, Mark; Norwood, Joey; Lowrey, Nikki

    2012-01-01

    The Contamination Control Team of Marshall Space Flight Center's Materials and Processes Laboratory supports many Programs/ Projects that design, manufacture, and test a wide range of hardware types that are sensitive to contamination and foreign object damage (FOD). Examples where contamination/FOD concerns arise include sensitive structural bondline failure, critical orifice blockage, seal leakage, and reactive fluid compatibility (liquid oxygen, hydrazine) as well as performance degradation of sensitive instruments or spacecraft surfaces such as optical elements and thermal control systems. During the design phase, determination of the sensitivity of a hardware system to different types or levels of contamination/FOD is essential. A contamination control and FOD control plan must then be developed and implemented through all phases of ground processing, and, sometimes, on-orbit use, recovery, and refurbishment. Implementation of proper controls prevents cost and schedule impacts due to hardware damage or rework and helps assure mission success. Current capabilities are being used to support recent and on-going activities for multiple Mission Directorates / Programs such as International Space Station (ISS), James Webb Space Telescope (JWST), Space Launch System (SLS) elements (tanks, engines, booster), etc. The team also advances Green Technology initiatives and addresses materials obsolescence issues for NASA and external customers, most notably in the area of solvent replacement (e.g. aqueous cleaners containing hexavalent chrome, ozone depleting chemicals (CFC s and HCFC's), suspect carcinogens). The team evaluates new surface cleanliness inspection and cleaning technologies (e.g. plasma cleaning), and maintains databases for processing support materials as well as outgassing and optical compatibility test results for spaceflight environments.

  2. DETECTION OF FECAL/INGESTA CONTAMINANTS ON POULTRY PROCESSING EQUIPMENT SURFACES BY VISIBLE AND NEAR-INFRARED REFLECTANCE SPECTROSCOPY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Visible and near-infrared (NIR) spectra and samples for laboratory microbial analysis were acquired of fecal contaminants, ingesta contaminants, and bare processing equipment surfaces (rubber and stainless steel) in a commercial poultry processing plant. Spectra were analyzed in the visible region ...

  3. Real-time image processing for rapid contaminant detection on broiler carcasses

    NASA Astrophysics Data System (ADS)

    Park, Bosoon; Lawrence, Kurt C.; Windham, William R.; Snead, M. Preston

    2004-11-01

    Recently, the imaging research group at Russell Research Center, ARS in Athens, Georgia has developed a real-time multispectral imaging system for fecal and ingesta contaminant detection on broiler carcasses. The prototype system includes a common aperture camera with three optical trim filters (515.4, 566.4 and 631-nm wavelength), which were selected by visible/NIR spectroscopy and validated by a hyperspectral imaging system. The preliminary results showed that the multispectral imaging technique can be used effectively for detecting feces (from duodenum, ceca, and colon) and ingesta on the surface of poultry carcasses with a processing speed of 140 birds per minute. The accuracy for the detection of fecal and ingesta contaminates was 96%. However, the system contains many false positives including scabs, feathers, and boundaries. This paper demonstrates calibration of common aperture multispectral imaging hardware and real-time multispectral image processing software. The software design, especially the Unified Modeling Language (UML) design approach was used to develop real-time image processing software for on-line application. The UML models including class, object, activity, sequence, and collaboration diagram were discussed. Both hardware and software for a real-time fecal and ingesta contaminant detection were tested at the pilot-scale poultry processing line.

  4. EMERGING TECHNOLOGY BULLETIN: PROCESS FOR THE TREATMENT OF VOLATILE ORGANIC CARBON AND HEAVY-METAL- CONTAMINATED SOIL - INTERNATIONAL TECHNOLOGY CORPORATION

    EPA Science Inventory

    The batch steam distillation and metal extraction treatment process is a two-stage system that treats soils contaminated with organics and inorganics. This system uses conventional, readily available process equipment, and does not produce hazardous combustion products. Hazar...

  5. Evaluation of radiation resistance of the bacterial contaminants from femoral heads processed for allogeneic transplantation

    NASA Astrophysics Data System (ADS)

    Singh, Rita; Singh, Durgeshwer

    2009-09-01

    Femoral heads excised during surgery were obtained from patients who had a fractured neck of the femur and were processed as bone allograft. The bacterial contaminants were isolated from femoral heads at different stages of processing and identified based on morphological characteristics and biochemical tests. Bacterial contaminants on bone were mainly Gram-positive bacilli and cocci (58.3%). Twenty-four isolates from bone samples were screened for resistance to radiation. The D10 values for Gram-negative bacteria isolated from femoral heads ranged from 0.17 to 0.65 kGy. Higher D10 values 0.56-1.04 kGy were observed for Gram-positive bacterial isolates.

  6. A signal processing framework for simultaneous detection of multiple environmental contaminants

    NASA Astrophysics Data System (ADS)

    Chakraborty, Subhadeep; Manahan, Michael P.; Mench, Matthew M.

    2013-11-01

    The possibility of large-scale attacks using chemical warfare agents (CWAs) has exposed the critical need for fundamental research enabling the reliable, unambiguous and early detection of trace CWAs and toxic industrial chemicals. This paper presents a unique approach for the identification and classification of simultaneously present multiple environmental contaminants by perturbing an electrochemical (EC) sensor with an oscillating potential for the extraction of statistically rich information from the current response. The dynamic response, being a function of the degree and mechanism of contamination, is then processed with a symbolic dynamic filter for the extraction of representative patterns, which are then classified using a trained neural network. The approach presented in this paper promises to extend the sensing power and sensitivity of these EC sensors by augmenting and complementing sensor technology with state-of-the-art embedded real-time signal processing capabilities.

  7. Recharge processes drive sulfate reduction in an alluvial aquifer contaminated with landfill leachate

    USGS Publications Warehouse

    Scholl, M.A.; Cozzarelli, I.M.; Christenson, S.C.

    2006-01-01

    present in the root zone, and SO42- reduction may be coupled to methane oxidation. The results show that sulfur (and possibly nitrogen) redox processes within the top 2??m of the aquifer are directly related to recharge timing and seasonal water level changes in the aquifer. The results suggest that SO42- reduction associated with the infiltration of recharge may be a significant factor affecting natural attenuation of contaminants in alluvial aquifers. ?? 2006 Elsevier B.V. All rights reserved.

  8. NaK loop testing of thermoelectric converter modules (SNAP program)

    NASA Technical Reports Server (NTRS)

    Johnson, J. L.

    1973-01-01

    The history of testing of compact tubular modules in flowing NaK loops is summarized. Test procedures, data handling, and instrument calibration are discussed. Also included is descriptive information of the test facilities, operational problems encountered, and some recommendations for testing.

  9. Characterization of Queso Fresco made with Na/K salt blends and stored for 12 weeks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Health-conscious consumers are looking for ways to reduce dietary sodium yet want their cheeses to have the flavor, texture, and shelf-life of full-salt cheese. The objectives of this study were to determine the effects of different Na-K salt blends and storage on the compositional, sensorial, micro...

  10. Increased leucocyte Na-K ATPase in obesity: reversal following weight loss

    SciTech Connect

    Turaihi, K.; Baron, D.N.; Dandona, P.

    1987-09-01

    Ouabain-sensitive /sup 86/Rb influx and (/sup 3/H) ouabain binding capacity were investigated in the leucocytes of 17 obese patients and 15 control subjects. Both were significantly increased in the obese when compared with controls. Following dietary restriction and a 4% to 5% weight reduction in the obese over 2 weeks, (/sup 3/H) ouabain binding and ouabain-sensitive /sup 86/Rb influx (a model for K+ influx) decreased to levels similar to those in controls. This shows that the number of Na-K ATPase sites on leucocyte membranes of the obese are significantly increased and that this is associated with accelerated /sup 86/Rb transport. Since both of these indices decreased following 4% to 5% reduction in body weight while the patients were still obese, increased Na-K ATPase is neither a marker of nor cardinal to the pathogenesis of obesity. We conclude that (1) increase in Na-K ATPase units and /sup 86/Rb influx are not characteristic of obesity itself and (2) dietary restriction over the short-term with limited weight reduction restores Na-K ATPase units and /sup 86/Rb influx to normal.

  11. Size distribution of NaK droplets released during RORSAT reactor core ejection

    NASA Astrophysics Data System (ADS)

    Wiedemann, C.; Oswald, M.; Stabroth, S.; Klinkrad, H.; Vörsmann, P.

    NaK droplets consist of eutectic sodium-potassium alloy and have been released during RORSAT reactor core ejections mostly on orbits close to 950 km altitude. They contributed to the space debris environment in the centimeter and millimeter regime. NaK droplets have been modeled before in ESAs MASTER Debris and Meteoroid Environment Model. The approach is currently revised for the MASTER 2005 upgrade. The new NaK model gives estimations of the parameters of the size distribution function, which are based on physical relations only. NASA radar observations confirm this physical approach. A bimodal size distribution is derived, which is based on the Rosin-Rammler equation. The Rosin-Rammler equation is an empirical volume distribution function. The number of parameters is limited to two. It is likely that the coolant system contains two types of orifice diameters. This makes it necessary to apply the Rosin-Rammler distribution twice, resulting in a bimodal size distribution with altogether four parameters. The comparison shows that the new NaK model is in good agreement with the NASA model, which is based on radar observations. Results of orbit propagation simulation runs are presented.

  12. 36. ARCHITECTURAL AND STRUCTURAL DETAILS OF ELEVATOR HOUSING, NaK HEATER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. ARCHITECTURAL AND STRUCTURAL DETAILS OF ELEVATOR HOUSING, NaK HEATER STACK ROOF FLASHING, HOOD ELEVATION DETAIL. INCLUDES PARTIAL 'BILL OF MATERIAL.' INEEL DRAWING NUMBER 200-0633-00-287-106361. FLUOR NUMBER 5775-CPP-633-A-11. - Idaho National Engineering Laboratory, Old Waste Calcining Facility, Scoville, Butte County, ID

  13. Simulating Heterogeneous Infiltration and Contaminant leaching Processes at Chalk River, Ontario

    NASA Astrophysics Data System (ADS)

    Ali, M. A.; Ireson, A. M.; Keim, D.

    2015-12-01

    A study is conducted at a waste management area in Chalk River, Ontario to characterize flow and contaminant transport with the aim of contributing to improved hydrogeological risk assessment in the context of waste management. Field monitoring has been performed to gain insights into the unsaturated zone characteristics, moisture dynamics, and contaminant transport rates. The objective is to provide quantitative estimates of surface fluxes (quantification of infiltration and evaporation) and investigations of unsaturated zone processes controlling water infiltration and spatial variability in head distributions and flow rates. One particular issue is to examine the effectiveness of the clayey soil cap installed to prevent infiltration of water into the waste repository and the top sand soil cover above the clayey layer to divert the infiltrated water laterally. The spatial variability in the unsaturated zone properties and associated effects on water flow and contaminant transport observed at the site, have led to a concerted effort to develop improved model of flow and transport based on stochastic concepts. Results obtained through the unsaturated zone model investigations are combined with the hydrogeological and geochemical components and develop predictive tools to assess the long term fate of the contaminants at the waste management site.

  14. Molecular-Level Processes Governing the Interaction of Contaminants with Iron and Manganese Oxides - Final Report

    SciTech Connect

    Brown Jr., G. E.; Chambers, S. A.

    1999-10-31

    Many of the inorganic and organic contaminants present in sediments at DOE sites can be altered or destroyed by reduction and oxidation (redox) reactions occurring at mineral surfaces. A fundamental understanding of such redox processes provided by molecular-level studies on structurally and compositionally well-defined mineral surfaces will lead to: (i) improved models of contaminant fate and transport in geochemical systems, and (ii) optimized manipulation of these processes for remediation purposes. To contribute to this understanding, we will study, both experimentally and theoretically, redox processes involving three important contaminants - chromate ion, carbon tetrachloride, and trichloroethene TCE, on the following iron and manganese oxides - hematite, magnetite, maghemite, and pyrolusite. These oxides and their hydroxylated analogs commonly occur as coatings on minerals or as interfaces in the subsurface environment. Single-crystal surfaces of these oxides will be synthesized in carefully controlled fashion by molecular beam epitaxy. These surfaces, as well as high surface are powdered samples of these oxides, will be used in spectroscopic and kinetic experiments in both aqueous and gas phases. Our goal is to identify products and to determine the kinetics and mechanisms of surface-catalyzed redox reaction of Cr(VI) and CR(III), and the reductive dechlorination of carbon tetrachloride and TCE. The combination of theory and experiment will provide the base information needed to scale from the molecular level to the microscopic grain level minerals.

  15. NaK pool-boiler solar receiver durability bench test. Volume 2: Metallurgical analysis

    NASA Astrophysics Data System (ADS)

    Goods, S. H.; Bradshaw, R. W.

    1995-01-01

    The principal materials used in the construction of a NaK based pool-boiler were analyzed. The device, operated for 7500 hours, accumulated 1000 thermal cycles to a peak temperature of 750 C. Haynes 230, used to fabricate the pool-boiler vessel, was found to perform satisfactorily. Air-side corrosion of the pool-boiler vessel was insignificant. Internal surface of the alloy exhibited some NaK-induced elemental dissolution; this dissolution was somewhat more extensive where the alloy was exposed to the liquid metal compared to regions exposed only to NaK vapor; however, the corresponding metal loss in all regions was inconsequential, never exceeding more than a few microns. Autogenous seam welds of the alloy responded in a similar fashion, exhibiting only minimal metal loss over the course of the experiment. While there was 50% loss in ductility of the alloy there remained adequate ductility for the anticipated operating environment. An enhanced boiling nucleation surface comprised of stainless steel powder brazed to the vessel ID showed no change in its structure. It remained intact, showing no cracking after repeated thermal cycling. Other materials used in the experiment showed more extensive degradation after exposure to the NaK. IN 600, used to fabricate thermowells, exhibited extensive surface and intergranular dissolution. Grain boundary dissolution was sufficiently severe in one of the thermowells to cause an air leak, resulting in experiment termination. BNi-3, a brazing alloy used to join the pool-boiler vessel, endcaps and thermowells, showed some dissolution where it was exposed to the NaK as well as thermal aging effects. However, all brazes remained structurally sound. A nickel metal ribbon showed catastrophic dissolution, resulting in the formation of deep (greater than 30 (mu)m) pits and cavities. A zirconium metal foil used to getter oxygen from the NaK became extremely brittle.

  16. Reduced levels of skeletal muscle Na+K+ -ATPase in McArdle disease

    NASA Technical Reports Server (NTRS)

    Haller, R. G.; Clausen, T.; Vissing, J.; Blomqvist, C. G. (Principal Investigator)

    1998-01-01

    We evaluated the hypothesis that impaired sarcolemmal function associated with exaggerated potassium release, impaired potassium uptake, or both may contribute to exertional fatigue and abnormal circulatory responses to exercise in McArdle disease (MD). The cellular mechanism of exertional fatigue and muscle injury in MD is unknown but likely involves impaired function of the ATPases that couple ATP hydrolysis to cellular work, including the muscle sodium potassium pump (Na+K+-ATPase). However, the concentration of muscle Na+K+ pumps in MD is not known, and no studies have related exercise increases in blood potassium concentrations to muscle Na+K+ pump levels. We measured muscle Na+K+ pumps (3H-ouabain binding) and plasma K+ in response to 20 minutes of cycle exercise in six patients with MD and in six sex-, age-, and weight-matched sedentary individuals. MD patients had lower levels of 3H-ouabain binding (231 +/- 18 pmol/g w.w., mean +/- SD, range, 210 to 251) than control subjects (317 +/- 37, range, 266 to 371, p < 0.0004), higher peak increases in plasma potassium in response to 45 +/- 7 W cycle exercise (MD, 1.00 +/- 0.15 mmol/L; control subjects, 0.48 +/- 0.09; p < 0.0001), and mean exercise heart rate responses to exercise that were 45 +/- 12 bpm greater than control subjects. Our results indicate that Na+K+ pump levels are low in MD patients compared with healthy subjects and identify a limitation of potassium reuptake that could result in sarcolemmal failure during peak rates of membrane activation and may promote exaggerated potassium-activated circulatory responses to submaximal exercise. The mechanism of the low Na+K+ pump concentrations in MD is unknown but may relate to deconditioning or to disruption of a close functional relationship between membrane ion transport and glycolysis.

  17. Gill Na+-K+-2Cl- cotransporter abundance and location in Atlantic salmon: Effects of seawater and smolting

    USGS Publications Warehouse

    Pelis, R.M.; Zydlewski, J.; McCormick, S.D.

    2001-01-01

    Na+-K+-2Cl- cotransporter abundance and location was examined in the gills of Atlantic salmon (Salmo salar) during seawater acclimation and smolting. Western blots revealed three bands centered at 285, 160, and 120 kDa. The Na+-K+-2Cl- cotransporter was colocalized with Na+-K+-ATPase to chloride cells on both the primary filament and secondary lamellae. Parr acclimated to 30 parts per thousand seawater had increased gill Na+-K+-2Cl- cotransporter abundance, large and numerous Na+-K+-2Cl- cotransporter immunoreactive chloride cells on the primary filament, and reduced numbers on the secondary lamellae. Gill Na+-K+-2Cl- cotransporter levels were low in presmolts (February) and increased 3.3-fold in smolts (May), coincident with elevated seawater tolerance. Cotransporter levels decreased below presmolt values in postsmolts in freshwater (June). The size and number of immunoreactive chloride cells on the primary filament increased threefold during smolting and decreased in postsmolts. Gill Na+-K+-ATPase activity and Na+-K+-2Cl- cotransporter abundance increased in parallel during both seawater acclimation and smolting. These data indicate a direct role of the Na+-K+-2Cl- cotransporter in salt secretion by gill chloride cells of teleost fish.

  18. Geochemical information and isotopic ratios in pinpointing the rates of contamination processes generated at mine sites

    NASA Astrophysics Data System (ADS)

    Turunen, Kaisa; Kittilä, Anniina; Backnäs, Soile; Pasanen, Antti; Hendriksson, Nina

    2015-04-01

    The isotopic composition of water is an important fingerprinting method for tracing recharge sources, distribution processes and possible hydraulic connections of mine waters. However, since, the isotopes alone do not indicate the contamination derived from mining activities; also a set of geochemical analysis of harmful substance in water is acquired. This complex approach will allow a detailed insight in migration of potentially harmful substances, their reactions, mixing and dilution in ground and surface waters. The data can be applied also when comparing geogenic and anthropogenic emissions. Isotopic methods are rather new approach to estimate mining related emissions in Finland and thus, a novel approach of isotopic methods for investigation and monitoring of migration of harmful substances from mine sites are tested in two mine sites in Finland. The aim of this study is to assess the emission sources, flow paths and interaction between mine waters, groundwater and surface waters. A set of isotopic data, including S, Li, Mg, U, Sr, Pb, O, and H, will be combined with chemical information and physical parameters of water in order to assess the source and extent of possible contamination as well as the rates of processes that generate or at best attenuate the contamination. The results obtained from water analyses and field measurements will be used in hydrogeochemical modelling for the prediction of chemical transformation and long-term impacts of mining at study site and its surroundings.

  19. An Assessment of the International Space Station's Trace Contaminant Control Subassembly Process Economics

    NASA Technical Reports Server (NTRS)

    Perry J. L.; Cole, H. E.; El-Lessy, H. N.

    2005-01-01

    The International Space Station (ISS) Environmental Control and Life Support System includes equipment speci.cally designed to actively remove trace chemical contamination from the cabin atmosphere. In the U.S. on-orbit segment, this function is provided by the trace contaminant control subassembly (TCCS) located in the atmosphere revitalization subsystem rack housed in the laboratory module, Destiny. The TCCS employs expendable adsorbent beds to accomplish its function leading to a potentially signi.cant life cycle cost over the life of the ISS. Because maintaining the TCCSs proper can be logistically intensive, its performance in .ight has been studied in detail to determine where savings may be achieved. Details of these studies and recommendations for improving the TCCS s process economics without compromising its performance or crew health and safety are presented and discussed.

  20. Bioterrorism: processing contaminated evidence, the effects of formaldehyde gas on the recovery of latent fingermarks.

    PubMed

    Hoile, Rebecca; Walsh, Simon J; Roux, Claude

    2007-09-01

    In the present age of heightened emphasis on counter terrorism, law enforcement and forensic science are constantly evolving and adapting to the motivations and capabilities of terrorist groups and individuals. The use of biological agents on a population, such as anthrax spores, presents unique challenges to the forensic investigator, and the processing of contaminated evidence. In this research, a number of porous and non-porous items were contaminated with viable [corrected] spores and marked with latent fingermarks. The test samples were then subjected to a standard formulation of formaldehyde gas. Latent fingermarks were then recovered post decontamination using a range of methods. Standard fumigation, while effective at destroying viable spores, contributed to the degradation of amino acids leading to loss of ridge detail. A new protocol for formaldehyde gas decontamination was developed which allows for the destruction of viable spores and the successful recovery of latent marks, all within a rapid response time of less than 1 h. PMID:17767655

  1. High-performance self-aligned graphene transistors fabricated using contamination- and defect-free process

    NASA Astrophysics Data System (ADS)

    Park, Goon-Ho; Kim, Kwan-Soo; Fukidome, Hirokazu; Suemitsu, Tetsuya; Otsuji, Taiichi; Cho, Won-Ju; Suemitsu, Maki

    2016-06-01

    A contamination- and defect-free process is proposed for self-aligned graphene field-effect transistor (GFET) fabrication using a protective gold layer and by its etching. The gold layer serves as an electrode metal for both the source and drain. GFETs fabricated by this method exhibit superior electrical characteristics, such as an intrinsic carrier mobility of 8900 cm2 V‑1 s‑1 and a series resistance of 1520 Ω µm, which is ascribed to the effective blocking of unwanted contamination and defect formation as well as to the reduction in access length due to the self-aligned configuration. Our approach is quite promising as a device fabrication method for high-performance GFETs.

  2. Characterization of a site contaminated by waste from a monazite ore processing plant

    SciTech Connect

    Lauria, D.C.; Reis, V.R.; Nouailhetas, Y.; Godoy, J.M.; Agudo, E.G.

    1993-12-31

    A radiological survey of an area of 60,000 m{sup 2}, previously occupied by the Usina de Interlagos (USIN), a branch of the Brazilian State Monazite Company was conducted. External exposure gamma rates, surface soil, subsurface soil and groundwater concentration of the long-life radionuclides from the uranium and thorium decay chain were determined. Two areas, one of 4,800 m{sup 2} and other of 1,750 m{sup 2}, were found to be contaminated with different radioactive materials, originating from the chemical and physical processing of the monazite sand. {sup 228}Ra is present up to 2.2 {times} 10{sup 4} Bq/kg in soil and 93 Bq/l in groundwater. Based on future scenarios, an allowable residual contamination level of {sup 232}Th and {sup 226}Ra of around 200 Bq/kg was derived. Clean-up actions are suggested.

  3. Evaluation of six decontamination processes on actinide and fission product contamination

    SciTech Connect

    Conner, C.; Chamberlain, D.B.; Chen, L.

    1995-12-31

    In-situ decontamination technologies were evaluated for their ability to: (1) reduce equipment contamination levels to allow either free release of the equipment or land disposal, (2) minimize residues generated by decontamination, and (3) generate residues that are compatible with existing disposal technologies. Six decontamination processes were selected. tested and compared to 4M nitric acid, a traditional decontamination agent: fluoroboric acid (HBF{sub 4}), nitric plus hydrofluoric acid, alkaline persulfate followed by citric acid plus oxalic acid, silver(II) plus sodium persulfate plus nitric acid, oxalic acid plus hydrogen peroxide plus hydrofluoric acid, and electropolishing using nitric acid electrolyte. The effectiveness of these solutions was tested using prepared 304 stainless steel couponds contaminated with uranium, plutonium, americium, or fission products. The decontamination factor for each of the solutions and tests conditions were determined; the results of these experiments are presented.

  4. Electrochemical Processes for In-Situ Treatment of Contaminated Soils - Final Report - 09/15/1996 - 01/31/2001

    SciTech Connect

    Huang, Chin-Pao

    2001-05-31

    This project will study electrochemical processes for the in situ treatment of soils contaminated by mixed wastes, i.e., organic and inorganic. Soil samples collected form selected DOE waste sites will be characterized for specific organic and metal contaminants and hydraulic permeability. The soil samples are then subject to desorption experiments under various physical-chemical conditions such as pH and the presence of surfactants. Batch electro-osmosis experiments will be conducted to study the transport of contaminants in the soil-water systems. Organic contaminants that are released from the soil substrate will be treated by an advanced oxidation process, i.e., electron-Fantan. Finally, laboratory reactor integrating the elector-osmosis and elector-Fantan processes will be used to study the treatment of contaminated soil in situ.

  5. Carcinogenicity of consumption of red and processed meat: What about environmental contaminants?

    PubMed

    Domingo, José L; Nadal, Martí

    2016-02-01

    In October 26, 2015, the International Agency for Research on Cancer (IARC) issued a press release informing of the recent evaluation of the carcinogenicity of red and processed meat consumption. The consumption of red meat and processed meat was classified as "probably carcinogenic to humans", and as "carcinogenic to humans", respectively. The substances responsible of this potential carcinogenicity would be generated during meat processing, such as curing and smoking, or when meat is heated at high temperatures (N-nitroso-compounds, polycyclic aromatic hydrocarbons and heterocyclic aromatic amines). However, in its assessments, the IARC did not make any reference to the role that may pose some carcinogenic environmental pollutants, which are already present in raw or unprocessed meat. The potential role of a number of environmental chemical contaminants (toxic trace elements, polycyclic aromatic hydrocarbons, polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, polybrominated diphenyl ethers, polychlorinated diphenyl ethers, polychlorinated naphthalenes and perfluoroalkyl substances) on the carcinogenicity of consumption of meat and meat products is discussed in this paper. A case-study, Catalonia (Spain), is specifically assessed, while the influence of cooking on the concentrations of environmental pollutants is also reviewed. It is concluded that although certain cooking processes could modify the levels of chemical contaminants in food, the influence of cooking on the pollutant concentrations depends not only on the particular cooking process, but even more on their original contents in each specific food item. As most of these environmental pollutants are organic, cooking procedures that release or remove fat from the meat should tend to reduce the total concentrations of these contaminants in the cooked meat. PMID:26656511

  6. Hydrous pyrolysis/oxidation process for in situ destruction of chlorinated hydrocarbon and fuel hydrocarbon contaminants in water and soil

    DOEpatents

    Knauss, Kevin G.; Copenhaver, Sally C.; Aines, Roger D.

    2000-01-01

    In situ hydrous pyrolysis/oxidation process is useful for in situ degradation of hydrocarbon water and soil contaminants. Fuel hydrocarbons, chlorinated hydrocarbons, polycyclic aromatic hydrocarbons, petroleum distillates and other organic contaminants present in the soil and water are degraded by the process involving hydrous pyrolysis/oxidation into non-toxic products of the degradation. The process uses heat which is distributed through soils and water, optionally combined with oxygen and/or hydrocarbon degradation catalysts, and is particularly useful for remediation of solvent, fuel or other industrially contaminated sites.

  7. Mineral-Water Interface Processes Affecting Uranium Fate in Contaminated Sediments

    NASA Astrophysics Data System (ADS)

    Catalano, J. G.

    2011-12-01

    Widespread uranium contamination of soil, sediments, and groundwater systems has resulted from mining activities, nuclear weapon production, and energy generation. The fate and transport of uranium in such systems is strongly affected by geochemical processes occurring at mineral-water interfaces. I will present a summary of the mineral-water interface processes found to affect uranium fate in example contaminated sediments at the U.S. Department of Energy's Hanford sites and in related model systems. Processes occurring under oxic conditions will be the primary focus of this talk as under these conditions uranium is most mobile and thus presents the greatest hazard. Three dominant solid-phase uranium species are observed in contaminated soil and sediments at the Hanford site: uranyl silicates, uranyl phosphates, and uranyl adsorbed to clays and iron oxides. In deep sediments, uranyl silicates are found in microfractures in feldspar grains, likely because slow diffusion in such fractures maintains a high silicate activity. Such silicates are also found in waste-impacted shallow sediments and soil; waste fluids or evaporative processes may have generated the silicate activity needed to produce such phases. Uranyl phosphates are less abundant, occurring primarily in shallow sediments exposed to P-bearing waste fluids. However, remediation approaches under consideration may produce substantial quantities of uranyl phosphates in the future. Adsorbed uranyl is dispersed throughout contaminated soils and shallow sediments and likely has the greatest potential for remobilization. Analogue studies show that precipitation of uranyl phosphates is rapid when such phases are supersaturated and that both homogeneous and heterogeneous nucleation may occur. Specific adsorption of uranyl to minerals is strongly affected by the presence of complexation anions. Carbonate suppresses uranyl adsorption but also forms uranyl-carbonate ternary surface complexes. At conditions below

  8. Automated processing of forensic casework samples using robotic workstations equipped with nondisposable tips: contamination prevention.

    PubMed

    Frégeau, Chantal J; Lett, C Marc; Elliott, Jim; Yensen, Craig; Fourney, Ron M

    2008-05-01

    An automated process has been developed for the analysis of forensic casework samples using TECAN Genesis RSP 150/8 or Freedom EVO liquid handling workstations equipped exclusively with nondisposable tips. Robot tip cleaning routines have been incorporated strategically within the DNA extraction process as well as at the end of each session. Alternative options were examined for cleaning the tips and different strategies were employed to verify cross-contamination. A 2% sodium hypochlorite wash (1/5th dilution of the 10.8% commercial bleach stock) proved to be the best overall approach for preventing cross-contamination of samples processed using our automated protocol. The bleach wash steps do not adversely impact the short tandem repeat (STR) profiles developed from DNA extracted robotically and allow for major cost savings through the implementation of fixed tips. We have demonstrated that robotic workstations equipped with fixed pipette tips can be used with confidence with properly designed tip washing routines to process casework samples using an adapted magnetic bead extraction protocol. PMID:18471209

  9. The α1 isoform of the Na+/K+ ATPase is up-regulated in dedifferentiated progenitor cells that mediate lens and retina regeneration in adult newts*

    PubMed Central

    Vergara, M. Natalia; Smiley, Laura K.; Del Rio-Tsonis, Katia; Tsonis, Panagiotis A.

    2009-01-01

    Adult newts are able to regenerate their retina and lens after injury or complete removal through transdifferentiation of the pigmented epithelial tissues of the eye. This process needs to be tightly controlled, and several different mechanisms are likely to be recruited for this function. The Na+/K+ ATPase is a transmembrane protein that establishes electrochemical gradients through the transport of Na+ and K+ and has been implicated in the modulation of key cellular processes such as cell division, migration and adhesion. Even though it is expressed in all cells, its isoform composition varies with cell type and is tightly controlled during development and regeneration. In the present study we characterize the expression pattern of Na+/K+ ATPase α1 in the adult newt eye and during the process of lens and retina regeneration. We show that this isoform is up-regulated in undifferentiated cells during transdifferentiation. Such change in composition could be one of the mechanisms that newt cells utilize to modulate this process. PMID:18755185

  10. Modulation of Na+/K+ ATPase Activity by Hydrogen Peroxide Generated through Heme in L. amazonensis.

    PubMed

    Rocco-Machado, Nathália; Cosentino-Gomes, Daniela; Meyer-Fernandes, José Roberto

    2015-01-01

    Leishmania amazonensis is a protozoan parasite that occurs in many areas of Brazil and causes skin lesions. Using this parasite, our group showed the activation of Na+/K+ ATPase through a signaling cascade that involves the presence of heme and protein kinase C (PKC) activity. Heme is an important biomolecule that has pro-oxidant activity and signaling capacity. Reactive oxygen species (ROS) can act as second messengers, which are required in various signaling cascades. Our goal in this work is to investigate the role of hydrogen peroxide (H2O2) generated in the presence of heme in the Na+/K+ ATPase activity of L. amazonensis. Our results show that increasing concentrations of heme stimulates the production of H2O2 in a dose-dependent manner until a concentration of 2.5 μM heme. To confirm that the effect of heme on the Na+/K+ ATPase is through the generation of H2O2, we measured enzyme activity using increasing concentrations of H2O2 and, as expected, the activity increased in a dose-dependent manner until a concentration of 0.1 μM H2O2. To investigate the role of PKC in this signaling pathway, we observed the production of H2O2 in the presence of its activator phorbol 12-myristate 13-acetate (PMA) and its inhibitor calphostin C. Both showed no effect on the generation of H2O2. Furthermore, we found that PKC activity is increased in the presence of H2O2, and that in the presence of calphostin C, H2O2 is unable to activate the Na+/K+ ATPase. 100 μM of Mito-TEMPO was capable of abolishing the stimulatory effect of heme on Na+/K+ ATPase activity, indicating that mitochondria might be the source of the hydrogen peroxide production induced by heme. The modulation of L. amazonensis Na+/K+ ATPase by H2O2 opens new possibilities for understanding the signaling pathways of this parasite. PMID:26070143

  11. Natural attenuation processes for remediation of arsenic contaminated soils and groundwater.

    PubMed

    Wang, Suiling; Mulligan, Catherine N

    2006-12-01

    Arsenic (As) contamination presents a hazard in many countries. Natural attenuation (NA) of As-contaminated soils and groundwater may be a cost-effective in situ remedial option. It relies on the site intrinsic assimilative capacity and allows in-place cleanup. Sorption to solid phases is the principal mechanism immobilizing As in soils and removing it from groundwater. Hydroxides of iron, aluminum and manganese, clay and sulfide minerals, and natural organic matter are commonly associated with soils and aquifer sediments, and have been shown to be significant As adsorbents. The extent of sorption is influenced by As speciation and the site geochemical conditions such as pH, redox potential, and the co-occurring ions. Microbial activity may catalyze the transformation of As species, or mediate redox reactions thus influencing As mobility. Plants that are capable of hyperaccumulating As may translocate As from contaminated soils and groundwater to their tissues, providing the basis for phytoremediation. However, NA is subject to hydrological changes and may take substantial periods of time, thus requiring long-term monitoring. The current understanding of As NA processes remains limited. Sufficient site characterization is critical to the success of NA. Further research is required to develop conceptual and mathematical models to predict the fate and transport of As and to evaluate the site NA capacity. Engineering enhanced NA using environmentally benign products may be an effective alternative. PMID:17049728

  12. Combining SERCA2a activation and Na-K ATPase inhibition: a promising new approach to managing acute heart failure syndromes with low cardiac output.

    PubMed

    Gheorghiade, Mihai; Ambrosy, Andrew P; Ferrandi, Mara; Ferrari, Patrizia

    2011-08-01

    Heart failure (HF) patients are a medically complex and heterogeneous population with multiple cardiac and non-cardiac comorbidities. Although there are a multitude of etiologic substrates and initiating and amplifying mechanisms contributing to disease progression, these pathophysiologic processes ultimately all lead to impaired myocardial function. The myocardium must both pump oxygenated, nutrient-rich blood throughout the body (systolic function) and receive deoxygenated, nutrient-poor blood returning from the periphery (diastolic function). At the molecular level, it is well-established that Ca2+ plays a central role in excitation-contracting coupling with action potentials stimulating the opening of L-type Ca2+ in the plasma membrane and ryanodine receptor 2 (RyR2) in the sarcoplasmic reticulum (SR) membrane during systole and the Na-Ca2+ exchanger and SERCA2a returning Ca2+ to the extracellular space and SR, respectively, during diastole. However, there is increasing recognition that impaired Ca2+ cycling may contribute to myocardial dysfunction. Preclinical studies and clinical trials indicate that combining SERCA2a activation and Na-K ATPase inhibition may increase contractility (inotropy) and facilitate active relaxation (lusitropy), improving both systolic and diastolic functions. Istaroxime, a novel luso-inotrope that activates SERCA2a and inhibits the Na-K ATPase, is currently in phase II clinical development and has been shown to improve systolic and diastolic functions and central hemodynamics, increase systolic but not diastolic blood pressure, and decrease substantially heart rate. Irrespective of its clinical utility, the development of istaroxime has evolved our understanding of the clinical importance of inhibiting the Na-K ATPase in order to obtain a clinically significant effect from SERCA2a activation in the setting of myocardial failure. PMID:21878191

  13. Comparison of Eh and H2 measurements for delineating redox processes in a contaminated aquifer

    USGS Publications Warehouse

    Chapelle, Francis H.; Haack, Sheridan K.; Adriaens, Peter; Henry, Mark A.; Bradley, Paul M.

    1996-01-01

    Measurements of oxidation−reduction potential (Eh) and concentrations of dissolved hydrogen (H2) were made in a shallow groundwater system contaminated with solvents and jet fuel to delineate the zonation of redox processes. Eh measurements ranged from +69 to −158 mV in a cross section of the contaminated plume and accurately delineated oxic from anoxic groundwater. Plotting measured Eh and pH values on an equilibrium stability diagram indicated that Fe(III) reduction was the predominant redox process in the anoxic zone and did not indicate the presence of methanogenesis and sulfate reduction. In contrast, measurements of H2concentrations indicated that methanogenesis predominated in heavily contaminated sediments near the water table surface (H2 ∼ 7.0 nM) and that the methanogenic zone was surrounded by distinct sulfate-reducing (H2 ∼ 1−4 nM) and Fe(III)-reducing (H2 ∼ 0.1−0.8 nM) zones. The presence of methanogenesis, sulfate reduction, and Fe(III) reduction was confirmed by the distribution of dissolved oxygen, sulfate, Fe(II), and methane in groundwater. These results show that H2 concentrations were more useful for identifying anoxic redox processes than Ehmeasurements in this groundwater system. However, H2-based redox zone delineations are more reliable when H2 concentrations are interpreted in the context of electron-acceptor (oxygen, nitrate, sulfate) availability and the presence of final products [Fe(II), sulfide, methane] of microbial metabolism.

  14. Summary report on the demonstration of the Duratek process for treatment of mixed-waste contaminated groundwater

    SciTech Connect

    Singh, S.P.N.; Lomenick, T.F.

    1992-04-01

    This report presents the results of the demonstration of the Duratek process for removal of radioactive and hazardous waste compounds from mixed-waste contaminated groundwaters found at the Department of Energy (DOE) sites managed by Martin Marietta Energy Systems (Energy Systems). The process uses Duratek proprietary Durasil{reg_sign} ion-exchange media to remove the above contaminants from the water to produce treated water that can meet current and proposed drinking water quality standards with regard to the above contaminants. The demonstration showed that the process is simple, compact, versatile, and rugged and requires only minimal operator attention. It is thus recommended that this process be considered for remediating the mixed-waste contaminated waters found at the Energy Systems-managed DOE sites.

  15. Summary report on the demonstration of the Duratek process for treatment of mixed-waste contaminated groundwater

    SciTech Connect

    Singh, S.P.N.; Lomenick, T.F.

    1992-04-01

    This report presents the results of the demonstration of the Duratek process for removal of radioactive and hazardous waste compounds from mixed-waste contaminated groundwaters found at the Department of Energy (DOE) sites managed by Martin Marietta Energy Systems (Energy Systems). The process uses Duratek proprietary Durasil{reg sign} ion-exchange media to remove the above contaminants from the water to produce treated water that can meet current and proposed drinking water quality standards with regard to the above contaminants. The demonstration showed that the process is simple, compact, versatile, and rugged and requires only minimal operator attention. It is thus recommended that this process be considered for remediating the mixed-waste contaminated waters found at the Energy Systems-managed DOE sites.

  16. Geochemical and microbiological methods for evaluating anaerobic processes in an aquifer contaminated by landfill leachate

    USGS Publications Warehouse

    Cozzarelli, I.M.; Suflita, J.M.; Ulrich, G.A.; Harris, S.H.; Scholl, M.A.; Schlottmann, J.L.; Christenson, S.

    2000-01-01

    A combined geochemical and microbiological approach was needed to delineate the biogeochemical processes occurring in an aquifer contaminated by landfill leachate in Norman, OK, where the important microbially mediated reactions in an anoxic plume were iron reduction, sulfate reduction, and methanogenesis. The highest rates of sulfate reduction (13.2 ??M/day) were detected near the water table where sulfate levels were maximal (up to 4.6 mM). The enrichment of 34S in the sulfate pools (??34S of SO42- was 67-69%0), and dissolved hydrogen measurements provided additional support for the importance of sulfate reduction near the water table. Methane was detected in the center of the plume where sulfate was depleted. Microbial incubations demonstrated concomitant sulfate reduction and methanogenesis in the anoxic portion of the plume. Although high concentrations of soluble reduced iron were detected throughout the aquifer and H2 levels were indicative of iron reduction under steady-state conditions, microbiological experiments showed that iron reduction was active only at the edges of the sulfate-depleted portion of the plume. This study demonstrates the benefits of using a combined geochemical and microbiological approach to elucidate the spatial distribution of biogeochemical processes in contaminated aquifers.A combined geochemical and microbiological approach was needed to delineate the biogeochemical processes occurring in an aquifer contaminated by landfill leachate in Norman, OK, where the important microbially mediated reactions in an anoxic plume were iron reduction, sulfate reduction, and methanogenesis. The highest rates of sulfate reduction (13.2 ??M/day) were detected near the water table where sulfate levels were maximal (up to 4.6 mM). The enrichment of 34S in the sulfate pools (??34S of SO42- was 67-69 per mil), and dissolved hydrogen measurements provided additional support for the importance of sulfate reduction near the water table. Methane was

  17. Characterization of contamination through the use of position sensitive detectors and digital image processing

    SciTech Connect

    Shonka, J.J.; DeBord, D.M.; Bennett, T.E.; Weismann, J.J.

    1996-06-01

    This report describes development of a significant new method for monitoring radioactive surface contamination. A floor monitor prototype has been designed which uses position sensitive proportional counter based radiation detectors. The system includes a novel operator interface consisting of an enhanced reality display providing the operator with 3 dimensional contours of contamination and background subtracted stereo clicks. The process software saves electronic files of survey data at very high rates along with time stamped video recording and provides completely documented surveys in a visualization oriented data management system. The data management system allows simple re-assembly of strips of data that are taken with a linear PSPC and allows visualization and treatment of the data using algorithms developed for processing images from earth resource satellites. This report includes a brief history of the development path for the floor monitor, a discussion of position sensitive proportional counter technology, and details concerning the process software, post processor and hardware. The last chapter discusses the field tests that were conducted at five sites and an application of the data management system for data not associated with detector systems.

  18. Ecotoxicity of arsenic contaminated sludge after mixing with soils and addition into composting and vermicomposting processes.

    PubMed

    Vašíčková, Jana; Maňáková, Blanka; Šudoma, Marek; Hofman, Jakub

    2016-11-01

    Sludge coming from remediation of groundwater contaminated by industry is usually managed as hazardous waste despite it might be considered for further processing as a source of nutrients. The ecotoxicity of phosphorus rich sludge contaminated with arsenic was evaluated after mixing with soil and cultivation with Sinapis alba, and supplementation into composting and vermicomposting processes. The Enchytraeus crypticus and Folsomia candida reproduction tests and the Lactuca sativa root growth test were used. Invertebrate bioassays reacted sensitively to arsenic presence in soil-sludge mixtures. The root elongation of L. sativa was not sensitive and showed variable results. In general, the relationship between invertebrate tests results and arsenic mobile concentration was indicated in majority endpoints. Nevertheless, significant portion of the results still cannot be satisfactorily explained by As chemistry data. Composted and vermicomposted sludge mixtures showed surprisingly high toxicity on all three tested organisms despite the decrease in arsenic mobility, probably due to toxic metabolites of bacteria and earthworms produced during these processes. The results from the study indicated the inability of chemical methods to predict the effects of complex mixtures on living organisms with respect to ecotoxicity bioassays. PMID:27348256

  19. Exposure pathway evaluations for sites that processed asbestos-contaminated vermiculite.

    PubMed

    Anderson, Barbara A; Dearwent, Steve M; Durant, James T; Dyken, Jill J; Freed, Jennifer A; Moore, Susan McAfee; Wheeler, John S

    2005-01-01

    The Agency for Toxic Substances and Disease Registry (ATSDR) is currently evaluating the potential public health impacts associated with the processing of asbestos-contaminated vermiculite at various facilities around the country. Vermiculite ore contaminated with significant levels of asbestos was mined and milled in Libby, Montana, from the early 1920s until 1990. The majority of the Libby ore was then shipped to processing facilities for exfoliation. ATSDR initiated the National Asbestos Exposure Review (NAER) to identify and evaluate exposure pathways associated with these processing facilities. This manuscript details ATSDR's phased approach in addressing exposure potential around these sites. As this is an ongoing project, only the results from a selected set of completed site analyses are presented. Historical occupational exposures are the most significant exposure pathway for the site evaluations completed to date. Former workers also probably brought asbestos fibers home on their clothing, shoes, and hair, and their household contacts may have been exposed. Currently, most site-related worker and community exposure pathways have been eliminated. One community exposure pathway of indeterminate significance is the current exposure of individuals through direct contact with waste rock brought home for personal use as fill material, driveway surfacing, or soil amendment. Trace levels of asbestos are present in soil at many of the sites and buried waste rock has been discovered at a few sites; therefore, future worker and community exposure associated with disturbing on-site soil during construction or redevelopment at these sites is also a potential exposure pathway. PMID:15881979

  20. Salmonella Contamination of the Product and Environment of Selected Canadian Chicken Processing Plants

    PubMed Central

    Magwood, S. E.; Rigby, Charlotte; Fung, P. H. J.

    1967-01-01

    Of 345 market chicken carcasses received directly from selected processing plants across Canada, six yielded salmonellae. One of the plants submitted 122 carcasses none of which yielded these organisms. A second plant had one Salmonella-contaminated carcass among 20 which were examined. Each of these two plants was subected to detailed bacteriological examinations on four occasions. In these detailed examinations a total of 175 samples or specimens for culture were taken from a variety of surfaces including vent areas of carcasses, operators' hands, equipment surfaces and from water in tanks of iced birds. Twenty-five (14 per cent) of the cultures yielded salmonellae and all but one of these were either S. oranienburg or S. infantis. Isolations were made during five of the eight series of examinations. The evidence indicated that Salmonella-infected flocks were frequently slaughtered and that Salmonella contamination could become widespread in the plant during processing. The organisms are apparently eliminated from all but a small percentage of the carcasses during processing but opportunities exist for recontamination during subsequent handling. PMID:4227070

  1. The analysis and minimization of oxygen contamination in the powder processing of molybdenum disilicide

    SciTech Connect

    Shannon, K.

    1994-04-24

    Problems with MoSi{sub 2} include low-temperature fracture toughness, high-temperature creep resistance, and ``pest`` phenomena. Oxygen introduced by powder processing may be the cause of some of these problems. This study led to the following conclusions: Supplied powders have significant oxygen present prior to processing (up to 2.5 %), in the form of silica on the surface. This oxygen contamination did not increase by exposure to air at room temperature. An improved powder processing method was developed that uses glass encapsulation. Analysis of microstructures created from powders that contained 4900 to 24,100 ppM oxygen showed that the silica was transferred to the fully dense MoSi{sub 2} as SiO{sub 2} inclusions. A method of producing MoSi{sub 2} with less oxygen was attempted.

  2. Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1.

    PubMed

    Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

    2015-12-01

    In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by (137)Cesium ((137)Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as (132)Te-(132)I, (131)I, (134)Cs and (137)Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h(-1) per initial (137)Cs deposition of 1000 kBq m(-2), whereas it was 100 μGy h(-1) around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m(-2) for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums ((134)Cs + (137)Cs) around Chernobyl and Fukushima-1, respectively. PMID:26568603

  3. Hygiene and Safety in the Meat Processing Environment from Butcher Shops: Microbiological Contamination and Listeria monocytogenes.

    PubMed

    da Silva, Danilo Augusto Lopes; Dias, Mariane Rezende; Cossi, Marcus Vinícius Coutinho; de Castilho, Natália Parma Augusto; Camargo, Anderson Carlos; Nero, Lúis Augusto

    2016-04-01

    The quality and safety of meat products can be estimated by assessing their contamination by hygiene indicator microorganisms and some foodborne pathogens, with Listeria monocytogenes as a major concern. To identify the main sources of microbiological contamination in the processing environment of three butcher shops, surface samples were obtained from the hands of employees, tables, knives, inside butcher displays, grinders, and meat tenderizers (24 samples per point). All samples were subjected to enumeration of hygiene indicator microorganisms and detection of L. monocytogenes, and the obtained isolates were characterized by their serogroups and virulence genes. The results demonstrated the absence of relevant differences in the levels of microbiological contamination among butcher shops; samples with counts higher than reference values indicated inefficiency in adopted hygiene procedures. A total of 87 samples were positive for Listeria spp. (60.4%): 22 from tables, 20 from grinders, 16 from knives, 13 from hands, 9 from meat tenderizers, and 7 from butcher shop displays. Thirty-one samples (21.5%) were positive for L. monocytogenes, indicating the presence of the pathogen in meat processing environments. Seventy-four L. monocytogenes isolates were identified, with 52 from serogroups 1/2c or 3c and 22 from serogroups 4b, 4d, 4a, or 4c. All 74 isolates were positive for hlyA, iap, plcA, actA, and internalins (inlA, inlB, inlC, and inlJ). The establishment of appropriate procedures to reduce microbial counts and control the spread of L. monocytogenes in the final steps of the meat production chain is of utmost importance, with obvious effects on the quality and safety of meat products for human consumption. PMID:27052868

  4. Comparison of the accident process, radioactivity release and ground contamination between Chernobyl and Fukushima-1

    PubMed Central

    Imanaka, Tetsuji; Hayashi, Gohei; Endo, Satoru

    2015-01-01

    In this report, we have reviewed the basic features of the accident processes and radioactivity releases that occurred in the Chernobyl accident (1986) and in the Fukushima-1 accident (2011). The Chernobyl accident was a power-surge accident that was caused by a failure of control of a fission chain reaction, which instantaneously destroyed the reactor and building, whereas the Fukushima-1 accident was a loss-of-coolant accident in which the reactor cores of three units were melted by decay heat after losing the electricity supply. Although the quantity of radioactive noble gases released from Fukushima-1 exceeded the amount released from Chernobyl, the size of land area severely contaminated by 137Cesium (137Cs) was 10 times smaller around Fukushima-1 compared with around Chernobyl. The differences in the accident process are reflected in the composition of the discharged radioactivity as well as in the composition of the ground contamination. Volatile radionuclides (such as 132Te-132I, 131I, 134Cs and 137Cs) contributed to the gamma-ray exposure from the ground contamination around Fukishima-1, whereas a greater variety of radionuclides contributed significantly around Chernobyl. When radioactivity deposition occurred, the radiation exposure rate near Chernobyl is estimated to have been 770 μGy h−1 per initial 137Cs deposition of 1000 kBq m−2, whereas it was 100 μGy h−1 around Fukushima-1. Estimates of the cumulative exposure for 30 years are 970 and 570 mGy per initial deposition of 1000 kBq m−2 for Chernobyl and Fukusima-1, respectively. Of these exposures, 49 and 98% were contributed by radiocesiums (134Cs + 137Cs) around Chernobyl and Fukushima-1, respectively. PMID:26568603

  5. An α2-Na/K ATPase/α-adducin complex in astrocytes triggers non–cell autonomous neurodegeneration

    PubMed Central

    Gallardo, Gilbert; Barowski, Jessica; Ravits, John; Siddique, Teepu; Lingrel, Jerry B; Robertson, Janice; Steen, Hanno; Bonni, Azad

    2015-01-01

    Perturbations of astrocytes trigger neurodegeneration in several diseases, but the glial cell–intrinsic mechanisms that induce neurodegeneration remain poorly understood. We found that a protein complex of α2-Na/K ATPase and α-adducin was enriched in astrocytes expressing mutant superoxide dismutase 1 (SOD1), which causes familial amyotrophic lateral sclerosis (ALS). Knockdown of α2-Na/K ATPase or α-adducin in mutant SOD1 astrocytes protected motor neurons from degeneration, including in mutant SOD1 mice in vivo. Heterozygous disruption of the α2-Na/K ATPase gene suppressed degeneration in vivo and increased the lifespan of mutant SOD1 mice. The pharmacological agent digoxin, which inhibits Na/K ATPase activity, protected motor neurons from mutant SOD1 astrocyte–induced degeneration. Notably, α2-Na/K ATPase and α-adducin were upregulated in spinal cord of sporadic and familial ALS patients. Collectively, our findings define chronic activation of the α2-Na/K ATPase/α-adducin complex as a critical glial cell–intrinsic mechanism of non–cell autonomous neurodegeneration, with implications for potential therapies for neurodegenerative diseases. PMID:25344630

  6. An α2-Na/K ATPase/α-adducin complex in astrocytes triggers non-cell autonomous neurodegeneration.

    PubMed

    Gallardo, Gilbert; Barowski, Jessica; Ravits, John; Siddique, Teepu; Lingrel, Jerry B; Robertson, Janice; Steen, Hanno; Bonni, Azad

    2014-12-01

    Perturbations of astrocytes trigger neurodegeneration in several diseases, but the glial cell-intrinsic mechanisms that induce neurodegeneration remain poorly understood. We found that a protein complex of α2-Na/K ATPase and α-adducin was enriched in astrocytes expressing mutant superoxide dismutase 1 (SOD1), which causes familial amyotrophic lateral sclerosis (ALS). Knockdown of α2-Na/K ATPase or α-adducin in mutant SOD1 astrocytes protected motor neurons from degeneration, including in mutant SOD1 mice in vivo. Heterozygous disruption of the α2-Na/K ATPase gene suppressed degeneration in vivo and increased the lifespan of mutant SOD1 mice. The pharmacological agent digoxin, which inhibits Na/K ATPase activity, protected motor neurons from mutant SOD1 astrocyte-induced degeneration. Notably, α2-Na/K ATPase and α-adducin were upregulated in spinal cord of sporadic and familial ALS patients. Collectively, our findings define chronic activation of the α2-Na/K ATPase/α-adducin complex as a critical glial cell-intrinsic mechanism of non-cell autonomous neurodegeneration, with implications for potential therapies for neurodegenerative diseases. PMID:25344630

  7. NaK pool-boiler solar receiver durability bench test. Volume 2, Metallurgical analysis

    SciTech Connect

    Goods, S.H.; Bradshaw, R.W.

    1995-01-01

    The principal materials used in the construction of a NaKbased pool-boiler were analyzed. The device, operated for 7500 hours, accumulated 1000 thermal cycles to a peak temperature of 750{degrees}C. Haynes 230, used to fabricate the pool-boiler vessel, was found to perform satisfactorily. Air-side corrosion of the pool-boiler vessel was insignificant. Internal surface of the alloy exhibited some NaK-induced elemental dissolution; this dissolution was somewhat more extensive where the alloy was exposed to the liquid metal compared to regions exposed only to NaK vapor; however, the corresponding metal loss in all regions was inconsequential, never exceeding more than a few microns. Autogenous seam welds of the alloy responded in a similar fashion, exhibiting only minimal metal loss over the course of the experiment. While there was 50% loss in ductility of the alloy there remained adequate ductility for the anticipated operating environment. An enhanced boiling nucleation surface comprised of stainless steel powder brazed to the vessel ID showed no change in its structure. It remained intact, showing no cracking after repeated thermal cycling. Other materials used in the experiment showed more extensive degradation after exposure to the NaK. IN 600, used to fabricate thermowells, exhibited extensive surface and intergranular dissolution. Grain boundary dissolution was sufficiently severe in one of the thermowells to cause an air leak, resulting in experiment termination. BNi-3, a brazing alloy used to join the pool-boiler vessel, endcaps and thermowells, showed some dissolution where it was exposed to the NaK as well as thermal aging effects. However, all brazes remained structurally sound. A nickel metal ribbon showed catastrophic dissolution, resulting in the formation of deep (> 30 {mu}m) pits and cavities. A zirconium metal foil used to getter oxygen from the NaK became extremely brittle.

  8. Regulation of vascular endothelial cell volume by Na-K-2Cl cotransport.

    PubMed

    O'Neill, W C; Klein, J D

    1992-02-01

    The relationship between cell volume and Na-K-2Cl cotransport was studied in cultured bovine aortic endothelial cells. Hypertonic cell shrinkage increased bumetanide-sensitive, Na- or Cl-dependent K influx without altering bumetanide-insensitive influx. Greater stimulation of cotransport was observed in cells shrunken isosmotically either by preincubation in K-free and Na-free medium or by preincubation in hypotonic medium. Cell swelling, produced by preincubation in isotonic high-K medium, inhibited bumetanide-sensitive K influx. Simultaneous measurements of [3H]bumetanide binding and K influx revealed an increased number of binding sites without an increased influx per binding site in shrunken cells. Bumetanide did not alter the volume or ion content of cells in isotonic or hypertonic medium, indicating that no net influx of ions occurs through cotransport under these conditions. In isosmotically shrunken cells, there was greater stimulation of bumetanide-sensitive influx than of bumetanide-sensitive efflux, resulting in net bumetanide-sensitive influx. Rapid recovery of cell K, Na, and water occurred over 10-20 min and was inhibited by bumetanide or by the removal of external Na or Cl. These data demonstrate that Na-K-2Cl cotransport in aortic endothelial cells is regulated by cell volume, possibly through changes in the number of functional cotransporters, and mediates a brisk regulatory volume increase in isosmotically shrunken cells. Although thermodynamically favored, no net influx occurs through Na-K-2Cl cotransport in cells of normal volume or in hypertonically shrunken cells. This suggests additional regulation of cotransport, perhaps through trans-inhibition by intracellular Cl. Regulation of cell volume by Na-K-2Cl cotransport may be important in maintaining endothelial integrity. PMID:1539632

  9. METHODS OF PREVENTING THE SPREAD OF ZINC CONTAMINATION DURING VACUUM PROCESSING

    SciTech Connect

    Korinko, P.; Stoner, K.; Duncan, A.

    2013-11-20

    Radioactive zinc, {sup 65}Zn, was detected after a thermal vacuum process that extracted a desired product from articles out of a commercial light water reactor. While the facility is designed to handle radioactive materials, the location of the {sup 65}Zn was in an area that is not designed for gamma emitting contaminants. A series of experiments were conducted to entrain the contaminant in an easily replaceable trap within the process piping. The experiments were conducted with increasing levels of complexity. Initially a simple apparatus was developed to determine the effect of substrate temperature on the vapor capture, this was followed by experiments to determine the effect of filter pore size on pumping and trapping, finally the interactive effects of both pore size and temperature were evaluated. The testing was conducted on a system that used a roughing vacuum pump using model and prototypic materials. It was determined that heating the substrate to nominally 200°C resulted in effective trapping on the model as well as prototypic material.

  10. Quantum control of ultracold NaK polar molecules in optical traps

    NASA Astrophysics Data System (ADS)

    Li, Ming; Petrov, Alexander; Makrides, Constantinos; Kotochigova, Svetlana

    2016-05-01

    Selection of trapping conditions with ultracold molecules, where internal states experience identical trapping potentials, brings substantial benefits for the ultimate control of their internal degrees of freedom. Here we present our work on the control of NaK molecules, when they are subjected to both trapping laser light and external electric and magnetic fields. First, we calculated parallel and perpendicular polarizabilities using a coupled-cluster method at the CCSD level. This enables us to determine the differential Stark shifts of rotational levels of NaK as a function of orientation of external fields. The hyperfine and Zeeman structure of these rotational states was obtained using an effective spin Hamiltonian. We find that under the experimental conditions with NaK, the hyperfine sublevels of the J = 1 rotational state are significantly mixed by the trapping laser light so that the simplified model of Ref. for ``magic'' conditions can not be applied. Adding a modest static electric field, however, can minimize the mixing of magnetic sublevels and make it easier to find ``magic'' conditions. This work is supported by the ARO-MURI Grant No. W911NF-12-1-0476 and the NSF Grant No. PHY-1308573.

  11. Insulin regulation of Na/K pump activity in rat hepatoma cells

    SciTech Connect

    Gelehrter, T.D.; Shreve, P.D.; Dilworth, V.M.

    1984-05-01

    Insulin rapidly increases Na/K pump activity in HTC rat hepatoma cells in tissue culture, as measured by the ouabain-sensitive influx of the potassium analogue 86Rb+. Increased influx is observed within minutes and is maximal (70% above control) within 1-2 h. The effect appears to be mediated by the insulin receptors, as: the concentration dependence on insulin is identical to that for insulin induction of tyrosine aminotransferase and stimulation of 2-aminoisobutyric acid transport, proinsulin is 6% as potent as insulin, and the effect is blocked by anti-receptor antibodies. The early stimulation of potassium influx is not blocked by cycloheximide and is not associated with an increased number of pump sites as measured by /sup 3/H-ouabain binding. The insulin effect is blocked by amiloride, which blocks sodium influx, and is mimicked by the sodium ionophore monensin, which increases sodium influx and intracellular accumulation. Insulin also rapidly increases the initial rate of /sup 22/Na+ influx, suggesting that insulin may enhance Na/K pump activity, in part, by increasing intracellular sodium concentration. Incubation of HTC cells with insulin for 24 h causes complete unresponsiveness to the insulin induction of transaminase and stimulation of amino acid transport, a phenomenon mediated by postbinding mechanisms. In contrast, similar incubation with insulin does not cause unresponsiveness to the insulin stimulation of Na/K pump activity. Therefore, the site of regulation of responsiveness to insulin must be distal to, or separate from, those events causing stimulation of ion fluxes.

  12. Electrochemical iron generation: The ideal process for simultaneous removal of heavy metals from contaminated groundwater

    SciTech Connect

    Brewster, M.D.

    1993-12-31

    At most Superfund sites, many heavy metals must be removed from contaminated groundwater. Simultaneous extraction is complicated due to the various chemical properties that metals exhibit. A comprehensive understanding of solubilities, oxidation states, and adsorptive mechanisms is needed to accomplish treatment objectives. This paper uses data from treatability tests conducted on groundwater from the King of Prussia Technical Corporation Site to discuss the electrochemical iron generation process developed by Andco Environmental Processes, Inc. Electrical current and sacrificial steel electrodes were used to put ferrous ions into solution. The chemistry was properly manipulated to provide adsorption and coprecipitation conditions capable of simultaneously removing beryllium, cadmium, chromium, copper, iron, manganese, mercury, nickel, and zinc. Strict cleanup levels were required since the site is located within Pinelands National Reserve and adjacent to New Jersey`s Winslow Wildlife Refuge. System design, operating costs, and sludge production rate are also discussed.

  13. Remediation of Pb/Cr co-contaminated soil using electrokinetic process and approaching electrode technique.

    PubMed

    Ng, Yee-Sern; Sen Gupta, Bhaskar; Hashim, Mohd Ali

    2016-01-01

    Electrokinetic process has emerged as an important tool for remediating heavy metal-contaminated soil. The process can concentrate heavy metals into smaller soil volume even in the absence of hydraulic flow. This makes it an attractive soil pre-treatment method before other remediation techniques are applied such that the chemical consumption in the latter stage can be reduced. The present study evaluates the feasibility of electrokinetic process in concentrating lead (Pb) and chromium (Cr) in a co-contaminated soil using different types of wetting agents, namely 0.01 M NaNO3, 0.1 M citric acid and 0.1 M EDTA. The data obtained showed that NaNO3 and citric acid resulted in poor Pb electromigration in this study. As for Cr migration, these agents were also found to give lower electromigration rate especially at low pH region as a result of Cr(VI) adsorption and possible reduction into Cr(III). In contrast, EDTA emerged as the best wetting agent in this study as it formed water-soluble anionic complexes with both Pb and Cr. This provided effective one-way electromigration towards the anode for both ions, and they were accumulated into smaller soil volume with an enrichment ratio of 1.55-1.82. A further study on the application of approaching cathode in EDTA test showed that soil alkalisation was achieved, but this did not provide significant enhancement on electromigration for Pb and Cr. Nevertheless, the power consumption for electrokinetic process was decreased by 22.5%. PMID:26330317

  14. Selective suppression of bacterial contaminants by process conditions during lignocellulose based yeast fermentations

    PubMed Central

    2011-01-01

    Background Contamination of bacteria in large-scale yeast fermentations is a serious problem and a threat to the development of successful biofuel production plants. Huge research efforts have been spent in order to solve this problem, but additional ways must still be found to keep bacterial contaminants from thriving in these environments. The aim of this project was to develop process conditions that would inhibit bacterial growth while giving yeast a competitive advantage. Results Lactic acid bacteria are usually considered to be the most common contaminants in industrial yeast fermentations. Our observations support this view but also suggest that acetic acid bacteria, although not so numerous, could be a much more problematic obstacle to overcome. Acetic acid bacteria showed a capacity to drastically reduce the viability of yeast. In addition, they consumed the previously formed ethanol. Lactic acid bacteria did not show this detrimental effect on yeast viability. It was possible to combat both types of bacteria by a combined addition of NaCl and ethanol to the wood hydrolysate medium used. As a result of NaCl + ethanol additions the amount of viable bacteria decreased and yeast viability was enhanced concomitantly with an increase in ethanol concentration. The successful result obtained via addition of NaCl and ethanol was also confirmed in a real industrial ethanol production plant with its natural inherent yeast/bacterial community. Conclusions It is possible to reduce the number of bacteria and offer a selective advantage to yeast by a combined addition of NaCl and ethanol when cultivated in lignocellulosic medium such as wood hydrolysate. However, for optimal results, the concentrations of NaCl + ethanol must be adjusted to suit the challenges offered by each hydrolysate. PMID:22185398

  15. Molecular methods to assess Listeria monocytogenes route of contamination in a dairy processing plant.

    PubMed

    Alessandria, Valentina; Rantsiou, Kalliopi; Dolci, Paola; Cocolin, Luca

    2010-07-31

    In this study we investigated the occurrence of Listeria monocytogenes in a dairy processing plant during two sampling campaigns in 2007 and 2008. Samples represented by semifinished and finished cheeses, swabs from the equipment and brines from the salting step, were subjected to analysis by using traditional and molecular methods, represented mainly by quantitative PCR. Comparing the results obtained by the application of the two approaches used, it became evident how traditional microbiological analysis underestimated the presence of L. monocytogenes in the dairy plant. Especially samples of the brines and the equipment swabs were positive only with qPCR. For some equipment swabs it was possible to detect a load of 10(4)-10(5) cfu/cm(2), while the modified ISO method employed gave negative results both before and after the enrichment step. The evidences collected during the first sampling year, highlighting a heavy contamination of the brines and of the equipment, lead to the implementation of specific actions that decreased the contamination in these samples during the 2008 campaign. However, no reduction in the number of L. monocytogenes positive final products was observed, suggesting that a more strict control is necessary to avoid the presence of the pathogen. All the isolates of L. monocytogenes were able to attach to abiotic surfaces, and, interestingly, considering the results obtained from their molecular characterization it became evident how strains present in the brines, were genetically connected with isolates from the equipment and from the final product, suggesting a clear route of contamination of the pathogen in the dairy plant. This study underlines the necessity to use appropriate analytical tools, such as molecular methods, to fully understand the spread and persistence of L. monocytogenes in food producing companies. PMID:20193970

  16. Treatment Processes for Removal of Wastewater Contaminants (WERF Report INFR8SG09)

    EPA Science Inventory

    This study investigated the nature of colloids associated with wastewater effluents. It also evaluated the association of emerging contaminants with these wastewater colloids. Two distinct emerging contaminants were investigated to gain general insight into the potential importan...

  17. Phytoremediation of a nitrogen-contaminated desert soil by native shrubs and microbial processes

    DOE PAGESBeta

    Glenn, Edward P.; Jordan, Fiona; Waugh, W. Joseph

    2016-02-24

    Here, we combined phytoremediation and soil microbial nitrification and denitrification cycles to reduce nitrate and ammonium levels at a former uranium mill site near Monument Valley, Arizona. Ammonia used in uranium extraction was present throughout the soil profile. Sulfate,applied as sulfuric acid to solubilize uranium, was also present in the soil. These contaminants were leaching from a denuded area where a tailings pile had been removed and were migrating away from the site in groundwater. We planted the source area with two deep-rooted native shrubs, Atriplex cansescens and Sarcobatus vermiculatus, and irrigated transplants for 11 years at 20% the ratemore » of potential evapotranspiration to stimulate growth, then discontinued irrigation for 4 years. Over 15 years, total nitrogen levels dropped 82%, from 347 to 64 mg kg–1. Analysis of δ15N supported our hypothesis that coupled microbial nitrification and denitrification processes were responsible for the loss of N. Soil sulfate levels changed little; however, evapotranspiration reduced sulfate leaching into the aquifer. For arid sites where traditional pump-and-treat methods are problematic, the Monument Valley data suggest that alternatives that incorporate native plants and rely on vadose zone biogeochemistry and hydrology could be a sustainable remediation for nitrogen contaminated soil.« less

  18. Electrokinetic-enhanced bioremediation of organic contaminants: a review of processes and environmental applications.

    PubMed

    Gill, R T; Harbottle, M J; Smith, J W N; Thornton, S F

    2014-07-01

    There is current interest in finding sustainable remediation technologies for the removal of contaminants from soil and groundwater. This review focuses on the combination of electrokinetics, the use of an electric potential to move organic and inorganic compounds, or charged particles/organisms in the subsurface independent of hydraulic conductivity; and bioremediation, the destruction of organic contaminants or attenuation of inorganic compounds by the activity of microorganisms in situ or ex situ. The objective of the review is to examine the state of knowledge on electrokinetic bioremediation and critically evaluate factors which affect the up-scaling of laboratory and bench-scale research to field-scale application. It discusses the mechanisms of electrokinetic bioremediation in the subsurface environment at different micro and macroscales, the influence of environmental processes on electrokinetic phenomena and the design options available for application to the field scale. The review also presents results from a modelling exercise to illustrate the effectiveness of electrokinetics on the supply electron acceptors to a plume scale scenario where these are limiting. Current research needs include analysis of electrokinetic bioremediation in more representative environmental settings, such as those in physically heterogeneous systems in order to gain a greater understanding of the controlling mechanisms on both electrokinetics and bioremediation in those scenarios. PMID:24875868

  19. Reservoir and contaminated sediments impacts in high-Andean environments: Morphodynamic interactions with biogeochemical processes

    NASA Astrophysics Data System (ADS)

    Escauriaza, C. R.; Contreras, M. T.; Müllendorff, D. A.; Pasten, P.; Pizarro, G. E.

    2014-12-01

    Rapid changes due to anthropic interventions in high-altitude environments, such as the Altiplano region in South America, require new approaches to understand the connections between physical and biogeochemical processes. Alterations of the water quality linked to the river morphology can affect the ecosystems and human development in the long-term. The future construction of a reservoir in the Lluta river, located in northern Chile, will change the spatial distribution of arsenic-rich sediments, which can have significant effects on the lower parts of the watershed. In this investigation we develop a coupled numerical model to predict and evaluate the interactions between morphodynamic changes in the Lluta reservoir, and conditions that can potentially desorb arsenic from the sediments. Assuming that contaminants are mobilized under anaerobic conditions, we calculate the oxygen concentration within the sediments to study the interactions of the delta progradation with the potential arsenic release. This work provides a framework for future studies aimed to analyze the complex connections between morphodynamics and water quality, when contaminant-rich sediments accumulate in a reservoir. The tool can also help to design effective risk management and remediation strategies in these extreme environments. Research has been supported by Fondecyt grant 1130940 and CONICYT/FONDAP Grant 15110017

  20. In-Situ Anaerobic Biosurfactant Production Process For Remediation Of DNAPL Contamination In Subsurface Aquifers

    NASA Astrophysics Data System (ADS)

    Albino, J. D.; Nambi, I. M.

    2009-12-01

    Microbial Enhanced Oil Recovery (MEOR) and remediation of aquifers contaminated with hydrophobic contaminants require insitu production of biosurfactants for mobilization of entrapped hydrophobic liquids. Most of the biosurfactant producing microorganisms produce them under aerobic condition and hence surfactant production is limited in subsurface condition due to lack of oxygen. Currently bioremediation involves expensive air sparging or excavation followed by exsitu biodegradation. Use of microorganisms which can produce biosurfactants under anaerobic conditions can cost effectively expedite the process of insitu bioremediation or mobilization. In this work, the feasibility of anaerobic biosurfactant production in three mixed anaerobic cultures prepared from groundwater and soil contaminated with chlorinated compounds and municipal sewage sludge was investigated. The cultures were previously enriched under complete anaerobic conditions in the presence of Tetrachloroethylene (PCE) for more than a year before they were studied for biosurfactant production. Biosurfactant production under anaerobic conditions was simulated using two methods: i) induction of starvation in the microbial cultures and ii) addition of complex fermentable substrates. Positive result for biosurfactant production was not observed when the cultures were induced with starvation by adding PCE as blobs which served as the only terminal electron acceptor. However, slight reduction in interfacial tension was noticed which was caused by the adherence of microbes to water-PCE interface. Biosurfactant production was observed in all the three cultures when they were fed with complex fermentable substrates and surface tension of the liquid medium was lowered below 35 mN/m. Among the fermentable substrates tested, vegetable oil yielded highest amount of biosurfactant in all the cultures. Complete biodegradation of PCE to ethylene at a faster rate was also observed when vegetable oil was amended to the

  1. Two functionally different Na/K pumps in cardiac ventricular myocytes

    PubMed Central

    1995-01-01

    The whole-cell patch-clamp technique was used to voltage clamp acutely isolated myocytes at -60 mV and study effects of ionic environment on Na/K pump activity. In quiescent guinea pig myocytes, normal intracellular Na+ is approximately 6 mM, which gives a total pump current of 0.25 +/- 0.09 pA/pF, and an inward background sodium current of 0.75 +/- 0.26 pA/pF. The average capacitance of a cell is 189 +/- 61 pF. Our main conclusion is the total Na/K pump current comprises currents from two different types of pumps, whose functional responses to the extracellular environment are different. Pump current was reversibly blocked with two affinities by extracellular dihydro-ouabain (DHO). We determined dissociation constants of 72 microM for low affinity (type-1) pumps and 0.75 microM for high affinity (type-h) pumps. These dissociation constants did not detectably change with two intracellular Na+ concentrations, one saturating and one near half- saturating, and with two extracellular K+ concentrations of 4.6 and 1.0 mM. Ion effects on type-h pumps were therefore measured using 5 microM DHO and on total pump current using 1 mM DHO. Extracellular K+ half- maximally activated the type-h pumps at 0.4 mM and the type-1 at 3.7 mM. Extracellular H+ blocked the type-1 pumps with half-maximal blockade at a pH of 7.71 whereas the type-h pumps were insensitive to extracellular pH. Both types of pumps responded similarly to changes in intracellular-Na+, with 9.6 mM causing half-maximal activation. Neither changes in intracellular pH between 6.0 and 7.2, nor concentrations of intracellular K+ of 140 mM or below, had any effect on either type of pump. The lack of any effect of intracellular K+ suggests the dissociation constants are in the molar range so this step in the pump cycle is not rate limiting under normal physiological conditions. Changes in intracellular-Na+ did not affect the half-maximal activation by extracellular K+, and vice versa. We found DHO-blockade of Na/K pump

  2. Woodchip-sulfur based heterotrophic and autotrophic denitrification (WSHAD) process for nitrate contaminated water remediation.

    PubMed

    Li, Rui; Feng, Chuanping; Hu, Weiwu; Xi, Beidou; Chen, Nan; Zhao, Baowei; Liu, Ying; Hao, Chunbo; Pu, Jiaoyang

    2016-02-01

    Nitrate contaminated water can be effectively treated by simultaneous heterotrophic and autotrophic denitrification (HAD). In the present study, woodchips and elemental sulfur were used as co-electron donors for HAD. It was found that ammonium salts could enhance the denitrifying activity of the Thiobacillus bacteria, which utilize the ammonium that is produced by the dissimilatory nitrate reduction to ammonium (DNRA) in the woodchip-sulfur based heterotrophic and autotrophic denitrification (WSHAD) process. The denitrification performance of the WSHAD process (reaction constants range from 0.05485 h(-1) to 0.06637 h(-1)) is better than that of sulfur-based autotrophic denitrification (reaction constants range from 0.01029 h(-1) to 0.01379 h(-1)), and the optimized ratio of woodchips to sulfur is 1:1 (w/w). No sulfate accumulation is observed in the WSHAD process and the alkalinity generated in the heterotrophic denitrification can compensate for alkalinity consumption by the sulfur-based autotrophic denitrification. The symbiotic relationship between the autotrophic and the heterotrophic denitrification processes play a vital role in the mixotrophic environment. PMID:26650451

  3. Probabilistic Round Trip Contamination Analysis of a Mars Sample Acquisition and Handling Process Using Markovian Decompositions

    NASA Technical Reports Server (NTRS)

    Hudson, Nicolas; Lin, Ying; Barengoltz, Jack

    2010-01-01

    A method for evaluating the probability of a Viable Earth Microorganism (VEM) contaminating a sample during the sample acquisition and handling (SAH) process of a potential future Mars Sample Return mission is developed. A scenario where multiple core samples would be acquired using a rotary percussive coring tool, deployed from an arm on a MER class rover is analyzed. The analysis is conducted in a structured way by decomposing sample acquisition and handling process into a series of discrete time steps, and breaking the physical system into a set of relevant components. At each discrete time step, two key functions are defined: The probability of a VEM being released from each component, and the transport matrix, which represents the probability of VEM transport from one component to another. By defining the expected the number of VEMs on each component at the start of the sampling process, these decompositions allow the expected number of VEMs on each component at each sampling step to be represented as a Markov chain. This formalism provides a rigorous mathematical framework in which to analyze the probability of a VEM entering the sample chain, as well as making the analysis tractable by breaking the process down into small analyzable steps.

  4. Use of a marker organism in poultry processing to identify sites of cross-contamination and evaluate possible control measures.

    PubMed

    Mead, G C; Hudson, W R; Hinton, M H

    1994-07-01

    1. Nine different sites at a poultry processing plant were selected in the course of a hazard analysis to investigate the degree of microbial cross-contamination that could occur during processing and the effectiveness of possible control measures. 2. At each site, carcases, equipment or working surfaces were inoculated with a non-pathogenic strain of nalidixic acid-resistant Escherichia coli K12; transmission of the organism among carcases being processed was followed qualitatively and, where appropriate, quantitatively. 3. The degree of cross-contamination and the extent to which it could be controlled by the proposed measures varied from one site to another. PMID:7953779

  5. Coupling between pore water fluxes, structural heterogeneity, and biogeochemical processes controls contaminant mobility, bioavailability, and toxicity in sediments

    NASA Astrophysics Data System (ADS)

    Xie, M.; Fetters, K.; Jarrett, B.; Yuen, J.; Cadoux, C.; EI-Natour, M.; Packman, A. I.; Gaillard, J.; Burton, G.

    2012-12-01

    Sediments can serve as both sinks and sources of contaminants in aquatic systems. Contaminants are typically not sequestered permanently in sediments, and instead release slowly to the water column, posing an ongoing threat to aquatic ecosystems and human health. Many processes, including hydrodynamic transport, sediment diagenesis, and bioturbation regulate the behavior and effects of contaminants in sediments. While many of these processes have been studied individually, it is extremely important to understand how they interact to control the form, flux and toxicity of metals in sediments. We used well-defined experimental mesocosms to investigate the effects of hydrodynamic and biological processes on the redistribution of metals between sediments, pore water and overlying water, associated changes in metals speciation, and resulting bioavailability and toxicity to benthic organisms. Metals speciation was evaluated in deposited and resuspended particles using x-ray absorption spectroscopy. We also used time-lapse photography and oxygen optode imaging to evaluate how bioturbation and bioirrigation control sediment structure, sediment mixing process, and oxygen delivery to sediments. In the extremely fine sediments used here, local contaminant fluxes are mainly dominated by diffusion, but episodic bioturbation and resuspension cause extreme variability in contaminant flux and increases oxidation of reduced sediments. Metals contamination substantially reduced bioturbation by indwelling organisms. Sediment resuspension decreased survival and increased tissue burden of epi-benthic organisms. Bioturbation mixed sediments as deep as several centimeters, while associated bioirrigation through worm burrows delivered oxygen over an order of magnitude deeper than local diffusion. These results show that it is important to understand how local transport processes, sediment chemistry, and biological activity interact to control rates and patterns of metals speciation and

  6. Coherent Control of Ground State NaK Molecules

    NASA Astrophysics Data System (ADS)

    Yan, Zoe; Park, Jee Woo; Loh, Huanqian; Will, Sebastian; Zwierlein, Martin

    2016-05-01

    Ultracold dipolar molecules exhibit anisotropic, tunable, long-range interactions, making them attractive for the study of novel states of matter and quantum information processing. We demonstrate the creation and control of 23 Na40 K molecules in their rovibronic and hyperfine ground state. By applying microwaves, we drive coherent Rabi oscillations of spin-polarized molecules between the rotational ground state (J=0) and J=1. The control afforded by microwave manipulation allows us to pursue engineered dipolar interactions via microwave dressing. By driving a two-photon transition, we are also able to observe Ramsey fringes between different J=0 hyperfine states, with coherence times as long as 0.5s. The realization of long coherence times between different molecular states is crucial for applications in quantum information processing. NSF, AFOSR- MURI, Alfred P. Sloan Foundation, DARPA-OLE

  7. Ochratoxin A contamination of coffee batches from Kenya in relation to cultivation methods and post-harvest processing treatments.

    PubMed

    Duris, Daniel; Mburu, Joseph K; Durand, Noël; Clarke, Renata; Frank, John M; Guyot, Bernard

    2010-06-01

    This study set out to assess the relative importance of sound and unsound beans in a batch of coffee with regard to ochratoxin A (OTA) contamination. Initially, unsound beans were found to account for 95% of contamination in a batch of coffee, whatever the methods used for post-harvest processing. It was also found that beans displaying traces of attacks by Colletotrichum kahawae were the greatest contributors to OTA contamination. In a second stage, the study compared the contamination of sound beans with that of beans attacked by Colletotrichum kahawae. On average, beans attacked by Colletotrichum kahawae had a statistically higher OTA content than sound beans (18.0 microg kg(-1) as opposed to 1.2 microg kg(-1)). In addition, the average OTA content in unsound beans varied depending on growing conditions. PMID:20175009

  8. The Impact of Biofilms on the Process of Back Diffusion From a Contaminated Rock Matrix

    NASA Astrophysics Data System (ADS)

    Yungwirth, G. A.; Novakowski, K. S.; Ross, N.

    2005-12-01

    Groundwater remediation in fractured rock settings is complicated by the diffusion of contaminants into the rock matrix and the subsequent back diffusion into the fractures. The process of back diffusion, in particular, leads to extended periods of low-level contamination in the fracture network that persists long after the source area is hydraulically or otherwise removed. In such a case, we hypothesize that back diffusion could be limited by growing a biofilm which coats the rock fracture surface and potentially invades the rock micropores. This would effectively sequester the contamination potentially in perpetuity. To explore the viability of this concept, diffusion experiments were conducted in which the effect of biofilm growth on diffusion through thin (0.8 to 1.2 cm) slices of dolostone core obtained from the Lockport Formation, Southern Ontario, was investigated. The experiments were conducted using a double-cell method, in which the core slices were encapsulated inside Teflon coated hydraulic hose, fitted with ultra high molecular weight polyethylene endcaps having stainless steel sample ports. Diffusion was established across the core slice by spiking one reservoir with a conservative tracer and monitoring the tracer arrival in the reservoir located on the other side of the coupon. The experiments were conducted both in the presence and absence of a biofilm. Biofilm was grown on the rock coupons in a separate bath before the coupons were transferred to the apparatus for the diffusion experiments. Microbial populations indigenous to the groundwater used in the bath were stimulated to form the biofilm with the addition of a beef extract and peptone nutrient broth in 1g/L concentration. The extent of biofilm growth was monitored using a modified Dubois et al (1956) colorimetric method for sugar determination. Results were simulated using an analytical model that was developed for the geometry of the diffusion experiments. Governing equations for the model

  9. Determination of dominant biogeochemical processes in a contaminated aquifer-wetland system using multivariate statistical analysis

    USGS Publications Warehouse

    Baez-Cazull, S. E.; McGuire, J.T.; Cozzarelli, I.M.; Voytek, M.A.

    2008-01-01

    Determining the processes governing aqueous biogeochemistry in a wetland hydrologically linked to an underlying contaminated aquifer is challenging due to the complex exchange between the systems and their distinct responses to changes in precipitation, recharge, and biological activities. To evaluate temporal and spatial processes in the wetland-aquifer system, water samples were collected using cm-scale multichambered passive diffusion samplers (peepers) to span the wetland-aquifer interface over a period of 3 yr. Samples were analyzed for major cations and anions, methane, and a suite of organic acids resulting in a large dataset of over 8000 points, which was evaluated using multivariate statistics. Principal component analysis (PCA) was chosen with the purpose of exploring the sources of variation in the dataset to expose related variables and provide insight into the biogeochemical processes that control the water chemistry of the system. Factor scores computed from PCA were mapped by date and depth. Patterns observed suggest that (i) fermentation is the process controlling the greatest variability in the dataset and it peaks in May; (ii) iron and sulfate reduction were the dominant terminal electron-accepting processes in the system and were associated with fermentation but had more complex seasonal variability than fermentation; (iii) methanogenesis was also important and associated with bacterial utilization of minerals as a source of electron acceptors (e.g., barite BaSO4); and (iv) seasonal hydrological patterns (wet and dry periods) control the availability of electron acceptors through the reoxidation of reduced iron-sulfur species enhancing iron and sulfate reduction. Copyright ?? 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

  10. Elucidation of Listeria monocytogenes Contamination Routes in Cold-Smoked Salmon Processing Plants Detected by DNA-Based Typing Methods

    PubMed Central

    Fonnesbech Vogel, Birte; Huss, Hans Henrik; Ojeniyi, Bente; Ahrens, Peter; Gram, Lone

    2001-01-01

    The contamination routes of Listeria monocytogenes in cold-smoked salmon processing plants were investigated by analyzing 3,585 samples from products (produced in 1995, 1996, 1998, and 1999) and processing environments (samples obtained in 1998 and 1999) of two Danish smokehouses. The level of product contamination in plant I varied from 31 to 85%, and no L. monocytogenes was found on raw fish (30 fish were sampled). In plant II, the levels of both raw fish and product contamination varied from 0 to 25% (16 of 185 raw fish samples and 59 of 1,000 product samples were positive for L. monocytogenes). A total of 429 strains of L. monocytogenes were subsequently compared by random amplified polymorphic DNA (RAPD) profiling, and 55 different RAPD types were found. The RAPD types detected on the products were identical to types found on the processing equipment and in the processing environment, suggesting that contamination of the final product (cold-smoked salmon) in both plants (but primarily in plant I) was due to contamination during processing rather than to contamination from raw fish. However, the possibility that raw fish was an important source of contamination of the processing equipment and environment could not be excluded. Contamination of the product occurred in specific areas (the brining and slicing areas). In plant I, the same RAPD type (RAPD type 12) was found over a 4-year period, indicating that an established in-house flora persisted and was not eliminated by routine hygienic procedures. In plant II, where the prevalence of L. monocytogenes was much lower, no RAPD type persisted over long periods of time, and several different L. monocytogenes RAPD types were isolated. This indicates that persistent strains may be avoided by rigorous cleaning and sanitation; however, due to the ubiquitous nature of the organism, sporadic contamination occurred. A subset of strains was also typed by using pulsed-field gel electrophoresis and amplified fragment length

  11. Elucidation of Listeria monocytogenes contamination routes in cold-smoked salmon processing plants detected by DNA-based typing methods.

    PubMed

    Fonnesbech Vogel, B; Huss, H H; Ojeniyi, B; Ahrens, P; Gram, L

    2001-06-01

    The contamination routes of Listeria monocytogenes in cold-smoked salmon processing plants were investigated by analyzing 3,585 samples from products (produced in 1995, 1996, 1998, and 1999) and processing environments (samples obtained in 1998 and 1999) of two Danish smokehouses. The level of product contamination in plant I varied from 31 to 85%, and no L. monocytogenes was found on raw fish (30 fish were sampled). In plant II, the levels of both raw fish and product contamination varied from 0 to 25% (16 of 185 raw fish samples and 59 of 1,000 product samples were positive for L. monocytogenes). A total of 429 strains of L. monocytogenes were subsequently compared by random amplified polymorphic DNA (RAPD) profiling, and 55 different RAPD types were found. The RAPD types detected on the products were identical to types found on the processing equipment and in the processing environment, suggesting that contamination of the final product (cold-smoked salmon) in both plants (but primarily in plant I) was due to contamination during processing rather than to contamination from raw fish. However, the possibility that raw fish was an important source of contamination of the processing equipment and environment could not be excluded. Contamination of the product occurred in specific areas (the brining and slicing areas). In plant I, the same RAPD type (RAPD type 12) was found over a 4-year period, indicating that an established in-house flora persisted and was not eliminated by routine hygienic procedures. In plant II, where the prevalence of L. monocytogenes was much lower, no RAPD type persisted over long periods of time, and several different L. monocytogenes RAPD types were isolated. This indicates that persistent strains may be avoided by rigorous cleaning and sanitation; however, due to the ubiquitous nature of the organism, sporadic contamination occurred. A subset of strains was also typed by using pulsed-field gel electrophoresis and amplified fragment length

  12. Hexavalent chromium removal in contaminated water using reticulated chitosan micro/nanoparticles from seafood processing wastes.

    PubMed

    Dima, Jimena Bernadette; Sequeiros, Cynthia; Zaritzky, Noemi E

    2015-12-01

    Chitosan particles (CH) were obtained from seafood processing wastes (shrimp shells) and physicochemically characterized; deacetylation degree of CH was measured by Infrared Spectroscopy (FTIR) and potentiometric titration; polymer molecular weight was determined by intrinsic viscosity measurements. Reticulated micro/nanoparticles of chitosan (MCH) with an average diameter close to 100nm were synthesized by ionic gelation of chitosan using tripolyphosphate (TPP), and characterized by SEM, size distribution and Zeta-potential. Detoxification capacities of CH and MCH were tested analyzing the removal of hexavalent chromium Cr(VI) from contaminated water, at different initial chromium concentrations. The effect of pH on adsorption capacity of CH and MCH was experimentally determined and analyzed considering the Cr(VI) stable complexes (anions) formed, the presence of protonated groups in chitosan particles and the addition of the reticulating agent (TPP). Chitosan crosslinking was necessary to adsorb Cr(VI) at pH<2 due to the instability of CH particles in acid media. Langmuir isotherm described better than Freundlich and Temkin equations the equilibrium adsorption data. Pseudo-second order rate provided the best fitting to the kinetic data in comparison to pseudo-first order and Elovich equations. Chemical analysis to determine the oxidation state of the adsorbed Cr, showed that Cr(VI) was adsorbed on CH particles without further reduction; in contrast Cr(VI) removed from the solution was reduced and bound to the MCH as Cr(III). The reduction of toxic Cr(VI) to the less or nontoxic Cr(III) by the reticulated chitosan micro/nanoparticles can be considered a very efficient detoxification technique for the treatment of Cr(VI) contaminated water. PMID:26151484

  13. Processing results of 1,800 gallons of mercury and radioactively contaminated mixed waste rinse solution

    SciTech Connect

    Thiesen, B.P.

    1993-01-01

    The mercury-contaminated rinse solution (INEL waste ID{number_sign} 123; File 8 waste) was successfully treated at the Idaho National Engineering Laboratory (INEL). This waste was generated during the decontamination of the Heat Transfer Reactor Experiment 3 (HTRE-3) reactor shield tank. Approximately 1,800 gal of waste was generated and was placed into 33 drums. Each drum contained precipitated sludge material ranging from 1--10 in. in depth, with the average depth of about 2.5 in. The pH of each drum varied from 3--11. The bulk liquid waste had a mercury level of 7.0 mg/l, which exceeded the Resource Conservation and Recovery Act (RCRA) limit of 0.2 mg/l. The average liquid bulk radioactivity was about 2.1 pCi/ml, while the average sludge contamination was about 13,800 pci/g. Treatment of the waste required separation of the liquid from the sludge, filtration, pH adjustment, and ion exchange. Because of difficulties in processing, three trials were required to reduce the mercury levels to below the RCRA limit. In the first trial, insufficient filtration of the waste allowed solid particulate produced during pH adjustment to enter into the ion exchange columns and ultimately the waste storage tank. In the second trial, the waste was filtered down to 0.1 {mu} to remove all solid mercury compounds. However, before filtration could take place, a solid mercury complex dissolved and mercury levels exceeded the RCRA limit after filtration. In the third trial, the waste was filtered through 0.3-A filters and then passed through the S-920 resin to remove the dissolved mercury. The resulting solution had mercury levels at 0.0186 mg/l and radioactivity of 0.282 pCi/ml. This solution was disposed of at the TAN warm waste pond, TAN782, TSF-10.

  14. Sodium and proton effects on inward proton transport through Na/K pumps.

    PubMed

    Mitchell, Travis J; Zugarramurdi, Camila; Olivera, J Fernando; Gatto, Craig; Artigas, Pablo

    2014-06-17

    The Na/K pump hydrolyzes ATP to export three intracellular Na (Nai) as it imports two extracellular K (Ko) across animal plasma membranes. Within the protein, two ion-binding sites (sites I and II) can reciprocally bind Na or K, but a third site (site III) exclusively binds Na in a voltage-dependent fashion. In the absence of Nao and Ko, the pump passively imports protons, generating an inward current (IH). To elucidate the mechanisms of IH, we used voltage-clamp techniques to investigate the [H]o, [Na]o, and voltage dependence of IH in Na/K pumps from ventricular myocytes and in ouabain-resistant pumps expressed in Xenopus oocytes. Lowering pHo revealed that Ho both activates IH (in a voltage-dependent manner) and inhibits it (in a voltage-independent manner) by binding to different sites. Nao effects depend on pHo; at pHo where no Ho inhibition is observed, Nao inhibits IH at all concentrations, but when applied at pHo that inhibits pump-mediated current, low [Na]o activates IH and high [Na]o inhibits it. Our results demonstrate that IH is a property inherent to Na/K pumps, not linked to the oocyte expression environment, explains differences in the characteristics of IH previously reported in the literature, and supports a model in which 1), protons leak through site III; 2), binding of two Na or two protons to sites I and II inhibits proton transport; and 3), pumps with mixed Na/proton occupancy of sites I and II remain permeable to protons. PMID:24940773

  15. Alcohol Excites Cerebellar Golgi Cells by Inhibiting the Na+/K+ ATPase

    PubMed Central

    Botta, Paolo; de Souza, Fabio M Simões; Sangrey, Thomas; De Schutter, Erik; Valenzuela, C Fernando

    2010-01-01

    Alcohol-induced alterations of cerebellar function cause motor coordination impairments that are responsible for millions of injuries and deaths worldwide. Cognitive deficits associated with alcoholism are also a consequence of cerebellar dysfunction. The mechanisms responsible for these effects of ethanol are poorly understood. Recent studies have identified neurons in the input layer of the cerebellar cortex as important ethanol targets. In this layer, granule cells (GrCs) receive the majority of sensory inputs to the cerebellum through the mossy fibers. Information flow at these neurons is gated by a specialized pacemaker interneuron known as the Golgi cell, which provides divergent GABAergic input to thousands of GrCs. In vivo electrophysiological experiments have previously shown that acute ethanol exposure abolishes GrC responsiveness to sensory inputs carried by mossy fibers. Slice electrophysiological studies suggest that ethanol causes this effect by potentiating GABAergic transmission at Golgi cell-to-GrC synapses through an increase in Golgi cell excitability. Using patch-clamp electrophysiological techniques in cerebellar slices and computer modeling, we show here that ethanol excites Golgi cells by inhibiting the Na+/K+ ATPase. Voltage-clamp recordings of Na+/K+ ATPase currents indicated that ethanol partially inhibits this pump and this effect could be mimicked by low concentrations of ouabain. Partial inhibition of Na+/K+ ATPase function in a computer model of the Golgi cell reproduced these experimental findings. These results establish a novel mechanism of action of ethanol on neuronal excitability, which likely has a role in ethanol-induced cerebellar dysfunction and may also contribute to neuronal functional alterations in other brain regions. PMID:20520600

  16. Lysine and the Na+/K+ Selectivity in Mammalian Voltage-Gated Sodium Channels.

    PubMed

    Li, Yang; Liu, Huihui; Xia, Mengdie; Gong, Haipeng

    2016-01-01

    Voltage-gated sodium (Nav) channels are critical in the generation and transmission of neuronal signals in mammals. The crystal structures of several prokaryotic Nav channels determined in recent years inspire the mechanistic studies on their selection upon the permeable cations (especially between Na+ and K+ ions), a property that is proposed to be mainly determined by residues in the selectivity filter. However, the mechanism of cation selection in mammalian Nav channels lacks direct explanation at atomic level due to the difference in amino acid sequences between mammalian and prokaryotic Nav homologues, especially at the constriction site where the DEKA motif has been identified to determine the Na+/K+ selectivity in mammalian Nav channels but is completely absent in the prokaryotic counterparts. Among the DEKA residues, Lys is of the most importance since its mutation to Arg abolishes the Na+/K+ selectivity. In this work, we modeled the pore domain of mammalian Nav channels by mutating the four residues at the constriction site of a prokaryotic Nav channel (NavRh) to DEKA, and then mechanistically investigated the contribution of Lys in cation selection using molecular dynamics simulations. The DERA mutant was generated as a comparison to understand the loss of ion selectivity caused by the K-to-R mutation. Simulations and free energy calculations on the mutants indicate that Lys facilitates Na+/K+ selection by electrostatically repelling the cation to a highly Na+-selective location sandwiched by the carboxylate groups of Asp and Glu at the constriction site. In contrast, the electrostatic repulsion is substantially weakened when Lys is mutated to Arg, because of two intrinsic properties of the Arg side chain: the planar geometric design and the sparse charge distribution of the guanidine group. PMID:27584582

  17. Sodium and Proton Effects on Inward Proton Transport through Na/K Pumps

    PubMed Central

    Mitchell, Travis J.; Zugarramurdi, Camila; Olivera, J. Fernando; Gatto, Craig; Artigas, Pablo

    2014-01-01

    The Na/K pump hydrolyzes ATP to export three intracellular Na (Nai) as it imports two extracellular K (Ko) across animal plasma membranes. Within the protein, two ion-binding sites (sites I and II) can reciprocally bind Na or K, but a third site (site III) exclusively binds Na in a voltage-dependent fashion. In the absence of Nao and Ko, the pump passively imports protons, generating an inward current (IH). To elucidate the mechanisms of IH, we used voltage-clamp techniques to investigate the [H]o, [Na]o, and voltage dependence of IH in Na/K pumps from ventricular myocytes and in ouabain-resistant pumps expressed in Xenopus oocytes. Lowering pHo revealed that Ho both activates IH (in a voltage-dependent manner) and inhibits it (in a voltage-independent manner) by binding to different sites. Nao effects depend on pHo; at pHo where no Ho inhibition is observed, Nao inhibits IH at all concentrations, but when applied at pHo that inhibits pump-mediated current, low [Na]o activates IH and high [Na]o inhibits it. Our results demonstrate that IH is a property inherent to Na/K pumps, not linked to the oocyte expression environment, explains differences in the characteristics of IH previously reported in the literature, and supports a model in which 1), protons leak through site III; 2), binding of two Na or two protons to sites I and II inhibits proton transport; and 3), pumps with mixed Na/proton occupancy of sites I and II remain permeable to protons. PMID:24940773

  18. Composition and process for organic and metal contaminant fixation in soil

    DOEpatents

    Schwitzgebel, Klaus

    1994-02-08

    A method and compositions using a first ferrous iron containing solution with the iron concentration in excess of theoretical requirements to treat a contaminated site to reduce hexavalent chromium to trivalent chromium and coprecipitate trivalent chromium with other heavy metals and using a second solution of silicate containing a destabilizing salt to form a relatively impermeable gel in the contaminated site thereby fixing metals and organics to the extent that there should be no detectable ground water contamination.

  19. Composition and process for organic and metal contaminant fixation in soil

    SciTech Connect

    Schwitzgebel, K.

    1994-02-08

    A method and compositions using a first ferrous iron containing solution with the iron concentration in excess of theoretical requirements are presented to treat a contaminated site. Hexavalent chromium is reduced to trivalent chromium and trivalent chromium is coprecipitated with other heavy metals. A second solution of silicate containing a destabilizing salt is used to form a relatively impermeable gel in the contaminated site thereby fixing metals and organics to the extent that there should be no detectable ground water contamination.

  20. Experimental investigation of fabrication process-, transportation-, storage, and handling-induced contamination of 157-nm reticles and vacuum UV cleaning

    NASA Astrophysics Data System (ADS)

    Okoroanyanwu, Uzodinma; Stepanenko, Nickolay; Vereecke, Guy; Eliat, Astrid; Kocsis, Michael K.; Kang, Young-Seog; Jonckheere, Rik M.; Conard, Thierry; Ronse, Kurt G.

    2004-05-01

    Mask fabrication process, transportation, storage, and handling contribute to contamination of 157nm reticles and modified fused silica substrates, resulting in transmission loss. A stable VUV cleaning procedure for contaminated binary, alternating, and attenuated phase shift reticles has been developed. This cleaning procedure was verified by lithographic imaging on the 157nm ASML MS-VII exposure scanner. A point-to-point steady state dose transmission uniformity range across a batch of 25 wafers (the exposure conditions of which were equivalent to that of a 300 mm wafer, 26mm×33mm fields, 50mJ/cm2) that were exposed with a modified fused silica substrate, was found to be <0.24% for a reticle that was cleaned prior to exposure using this VUV cleaning process. In-situ laser cleaning of contaminated mask substrates during exposure in the MS-VII resulted in 1% change in transmission at doses of up to 20 J/cm2, above which transmission remains stable (<0.24% variation). The cleaning procedure involves exposing the contaminated reticle in the UVO Reticle Cleaning Station for 30 minutes, using a cleaning gas mixture of N2/O2=99%/1%. Transmission loss due to contamination within the clean room is limited to 1 - 2 % and is reversible upon VUV cleaning. Flare levels of 3% were measured on contaminated reticle relative to a clean state of the same reticle. VUV cleaning is not only good for improving and maintaining stable mask transmission, but it is also good for preventing reticle contamination-induced flare. Contamination rate and contaminant type appear to be dependent on the storage environment of mask substrates and reticles. Typical contaminants included molecular acids (halogens, sulfur, sulfates), molecular bases (ammonia, amines), molecular condensables (hydrocarbons, alcohols, ketones, fatty acids, siloxanes, phthalate), molecular dopant (boron) and molecular metals (Ca, Mg, Al, Cu). Contamination of mask substrates appears to be through a competitive adsorption

  1. Efficacy of Microwave-Heating during Alkaline Processing of Fumonisin-Contaminated Maize

    PubMed Central

    MENDEZ-ALBORES, Abraham; CARDENAS-RODRIGUEZ, Denisse Anelem; VAZQUEZ-DURAN, Alma

    2014-01-01

    Abstract Background Fumonisins (a family of foodborne carcinogenic mycotoxins) cause health hazards to humans and animals in developing countries, and has also economic implications. Therefore, the efficacy of a novel environmental friendly nixtamalization procedure to make tortillas (the main staple food for the Mexican population) was investigated. Methods Maize contaminated with 2136.67 ng/g total fumonisins was processed into tortillas, starting with maize grits mixed with water and calcium hydroxide that was cooked in a microwave field at 2.45 GHz during 3.75 min, and steeped 3.5 h at room temperature. The steeped maize grits (nixtamal) was stone-ground into masa (maize dough), which was then used to make tortillas. Total fumonisin content was determined using monoclonal antibody columns. Results Masa contained 1998.33 ng/g total fumonisins, which represents 6.5% toxin reduction. Nevertheless, fumonisin concentration was reduced significantly in tortillas (up to 985.33 ng/g) due to the cooking process, corresponding to a cumulative toxin degradation of 54%. Tortillas were below the maximum tolerated level, considering the European Union regulatory limit for fumonisins in maize (1000 ng/g). The physicochemical and technological properties of tortillas were also considered within the acceptable margins of quality. Conclusion Microwave nixtamalization was not a feasible method to reduce fumonisin content in masa to acceptable levels; however, an effective extra-reduction occurred when masa was baking into tortillas. PMID:26060737

  2. Remediation of nitrate-contaminated surface water using sulfur and limestone autotrophic denitrification processes

    SciTech Connect

    Flere, J.M.; Zhang, T.C.

    1997-12-31

    The feasibility of using the sulfur/limestone autotrophic denitrification (SLAD) process as an in situ method for remediation of nitrate-contaminated surface water was investigated. Four bench-scale pond systems with working volumes of 21.4 liters each and hydraulic retention time (HRT) of 30 days were operated under mixed conditions. Under mixed (aerobic) conditions, with the addition of alkalinity to raise pH, NO{sub 3}{sup {minus}}-N removal in the SLAD ponds was 85--100%, while the control reactor showed negative removal. Sulfate production under mixed conditions was between 1,000--2,500 mg/l SO{sub 4}{sup 2{minus}}, which shows that 40--60 mg/l of SO{sub 4}{sup 2{minus}} is produced for every 1 mg/l of NO{sub 3}{sup {minus}}-N reduced. Although the system is very efficient in removing nitrates under simulated surface water conditions, the sulfate production makes the process questionable for use under aerobic conditions. However, batch experiments under anaerobic conditions demonstrate that system maybe very efficient in removing nitrate while not producing insufferable amounts of sulfates.

  3. Na/K citrate versus sodium bicarbonate in prevention of contrast-induced nephropathy.

    PubMed

    Abouzeid, Sameh Mohamed; ElHossary, Hossam E

    2016-05-01

    Contrast-induced nephropathy (CIN) is one of the important complications of radiographic procedures, especially in patients with chronic kidney disease. It is also one of the common causes of acute kidney injury. The pathogenesis is postulated to be the effect of oxygen- free radicals and hyperosmolar stress on the renal medulla. It is reported that the production of superoxide is most active at acid environment. K/Na citrate is well known as a urine alkalinization medium, and this has been evaluated earlier with standard hydration for reduction of CIN and was stated to be efficient. We aimed to determine the efficacy of Na/K citrate in reducing the frequency of CIN in comparison to sodium bicarbonate in patients after coronary angiography. Two hundred and ten patients with renal dysfunction [estimated glomerular filtration rate (eGFR), 60 mL/min/1.73 m(2) or less] who underwent elective or emergency coronary angiography (CAG) with/without percutaneous coronary intervention (PCI) at our institution were enrolled into the study. The patients were randomized into two groups, Group 1-Taking Na/K citrate and Group 2-Taking sodium bicarbonate. Radiographic contrast agent iohexol was used. Change in creatinine, percent change in creatinine, percent change in eGFR, change in serum potassium, and urine pH were all compared between the two groups. There was no significant difference for prevention of CIN when comparing the Na/K citrate with sodium bicarbonate solution in patients exposed to CAG with or without PCI. Mean absolute change in eGFR after 48 h after administration of contrast between sodium bicarbonate group and Na/K citrate group was -0.60 ± 1.58 versus -0.71 ± 1.38. Serum potassium decreased postprocedure in the sodium bicarbonate group than in the citrate group (3.90 ± 0.33 vs. 4.14 ± 0.39). Both agents are equally effective in reducing the incidence of CIN, but the citrate would possibly be a safer option for patients at risk of hypokalemia. PMID:27215244

  4. Investigation of gas-phase decontamination of internally radioactively contaminated gaseous diffusion process equipment and piping

    SciTech Connect

    Bundy, R.D.; Munday, E.B.

    1991-01-01

    Construction of the gaseous diffusion plants (GDPs) was begun during World War 2 to produce enriched uranium for defense purposes. These plants, which utilized UF{sub 6} gas, were used primarily for this purpose through 1964. From 1959 through 1968, production shifted primarily to uranium enrichment to supply the nuclear power industry. Additional UF{sub 6}-handling facilities were built in feed and fuel-processing plants associated with the uranium enrichment process. Two of the five process buildings at Oak ridge were shut down in 1964. Uranium enrichment activities at Oak Ridge were discontinued altogether in 1985. In 1987, the Department of Energy (DOE) decided to proceed with a permanent shutdown of the Oak Ridge Gaseous Diffusion Plant (ORGDP). DOE intends to begin decommissioning and decontamination (D D) of ORGDP early in the next century. The remaining two GDPs are expected to be shut down during the next 10 to 40 years and will also require D D, as will the other UF{sub 6}-handling facilities. This paper presents an investigation of gas- phase decontamination of internally radioactively contaminated gaseous diffusion process equipment and piping using powerful fluorinating reagents that convert nonvolatile uranium compounds to volatile UF{sub 6}. These reagents include ClF{sub 3}, F{sub 2}, and other compounds. The scope of D D at the GDPs, previous work of gas-phase decontamination, four concepts for using gas-phase decontamination, plans for further study of gas-phase decontamination, and the current status of this work are discussed. 13 refs., 15 figs.

  5. Properties of the Na+-K+ pump in human red cells with increased number of pump sites.

    PubMed Central

    Halperin, J A; Brugnara, C; Kopin, A S; Ingwall, J; Tosteson, D C

    1987-01-01

    We studied the Na+/K+ pump in red cells from an obese human subject (MAJ) in which the number of pumps/cell was 10-20 times higher than normal. Through measurements of the kinetic properties of several modes of operation of the Na+/K+ pump we determined that the pumps in MAJ cells are kinetically normal. In the presence of adequate metabolic substrate the maximum rates of Na+ pumping and lactate production saturated at 60 and 12 nmol/1 cell per h, respectively. Under physiological conditions pump and "leak" Na+ fluxes were similar in MAJ and normal cells. Since internal Na+ was lower in MAJ than in normal cells (Nai+ approximately 2 and 8 mmol/1 cell, respectively), we conclude that the reduction in cell Na+ allows the Na+/K+ pump in MAJ cells to operate at lower fraction of maximum capacity and to compensate for the increased number of pumps. PMID:2439543

  6. ADVANCED OXIDATION PROCESSES IN THE TREATMENT OF CONTAMINANT CANDIDATE LIST (CCL) COMPOUNDS

    EPA Science Inventory

    The current (2nd) Contaminant Candidate List was completed in 2005 by the United States EPA as an update to the Safe Drinking Water Act. The list of 42 chemical contaminants spans a wide array of classes, from pesticides to pharmaceuticals to elements, all of which are anticipate...

  7. REMOVAL OF ORGANIC CCL CONTAMINANTS FROM DRINKING WATERS BY MEMBRANE AND GAC PROCESSES

    EPA Science Inventory

    Bench-scale treatment data for membrane and granular activated carbon technologies are presented for the organic contaminants on the U.S. Environmental Protection Agency's Contaminant Candidate List (CCL). For granular activated carbon (GAC), isotherm results are presented and q...

  8. ADAPTIVE WATER SENSOR SIGNAL PROCESSING: EXPERIMENTAL RESULTS AND IMPLICATIONS FOR ONLINE CONTAMINANT WARNING SYSTEMS

    EPA Science Inventory

    A contaminant detection technique and its optimization algorithms have two principal functions. One is the adaptive signal treatment that suppresses background noise and enhances contaminant signals, leading to a promising detection of water quality changes at a false rate as low...

  9. Process Development for Spray Drying a Value-Added Extract from Aflatoxin Contaminated Peanut Meal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut meal, the primary byproduct of commercial oil crushing operations, is an excellent source of protein though aflatoxin contamination often limits applications for this material. Naturally aflatoxin contaminated (59 ppb) peanut meal dispersions were adjusted to pH 2.1 or pH 9.1, with or without...

  10. ENGINEERING APPLICATION OF BIOOXIDATION PROCESSES FOR TREATING PETROLEUM-CONTAMINATED SOIL

    EPA Science Inventory

    Throughout the U.S., the need for effective treatment of petroleum contaminated soil has escalated due to the increase in the number of underground storage tank (UST) systems being upgraded in response to EPA regulations. ptions for excavated contaminated soil have in the past be...

  11. Evaluation of a remediation process for lead contaminated soil by toxicity bioassays: Plants and earthworms

    SciTech Connect

    Chana, L.W.; Smith, K.

    1995-12-31

    Soil from a site contaminated with heavy metals (predominantly lead) was treated using the TERRAMET{reg_sign} lead extraction process. Earthworm acute toxicity and plant seed germination/root elongation (SG/RE) bioassays were used to evaluate the toxicity of the soil before treatment (BT), after treatment (AT) and after treatment, followed by rinsing with water, intended to simulate exposure to rainfall (RT). The results showed BT and RT were not toxic to earthworms in a 14-day exposure while AT showed significant toxicity. The LC{sub 50} values for Eisenia and Lumbricus were 44.04 and 28.83 (as % AT soil/test soil mixture), respectively. The phytotoxicity data indicated that all 3 test soils significantly inhibited lettuce SG/RE in a dose-related manner, with AT being the most phytotoxic. In oats, RT had no effect on SG/RE and AT was more toxic than BT. For the two local-site grass seeds tested (blue grama and sideoat grama), the AT soil was the most phytotoxic followed by BT and RT. The results suggest that the soil after this remediation process exerts significant toxicity on both plant and earthworm, but after a rain-simulating rinse, the toxicity is the same as, or less than, the toxicity before treatment. Further studies are in progress to confirm the assumption that the high salt concentrations generated by acidification during the leaching process, followed by neutralization are responsible for the increased toxicity of unrinsed soil in both plant and earthworm.

  12. Online Oxide Contamination Measurement and Purification Demonstration

    NASA Technical Reports Server (NTRS)

    Bradley, D. E.; Godfroy, T. J.; Webster, K. L.; Garber, A. E.; Polzin, K. A.; Childers, D. J.

    2011-01-01

    Liquid metal sodium-potassium (NaK) has advantageous thermodynamic properties indicating its use as a fission reactor coolant for a surface (lunar, martian) power system. A major area of concern for fission reactor cooling systems is system corrosion due to oxygen contaminants at the high operating temperatures experienced. A small-scale, approximately 4-L capacity, simulated fission reactor cooling system employing NaK as a coolant was fabricated and tested with the goal of demonstrating a noninvasive oxygen detection and purification system. In order to generate prototypical conditions in the simulated cooling system, several system components were designed, fabricated, and tested. These major components were a fully-sealed, magnetically-coupled mechanical NaK pump, a graphite element heated reservoir, a plugging indicator system, and a cold trap. All system components were successfully demonstrated at a maximum system flow rate of approximately 150 cc/s at temperatures up to 550 C. Coolant purification was accomplished using a cold trap before and after plugging operations which showed a relative reduction in oxygen content.

  13. Toxicological benchmarks for screening potential contaminants of concern for effects on soil and litter invertebrates and heterotrophic process

    SciTech Connect

    Will, M.E.; Suter, G.W. II

    1994-09-01

    One of the initial stages in ecological risk assessments for hazardous waste sites is the screening of contaminants to determine which of them are worthy of further consideration as {open_quotes}contaminants of potential concern.{close_quotes} This process is termed {open_quotes}contaminant screening.{close_quotes} It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to soil- and litter-dwelling invertebrates, including earthworms, other micro- and macroinvertebrates, or heterotrophic bacteria and fungi. This report presents a standard method for deriving benchmarks for this purpose, sets of data concerning effects of chemicals in soil on invertebrates and soil microbial processes, and benchmarks for chemicals potentially associated with United States Department of Energy sites. In addition, literature describing the experiments from which data were drawn for benchmark derivation. Chemicals that are found in soil at concentrations exceeding both the benchmarks and the background concentration for the soil type should be considered contaminants of potential concern.

  14. Hazard analysis of Listeria monocytogenes contaminations in processing of salted roe from walleye pollock (Theragra chalcogramma) in Hokkaido, Japan.

    PubMed

    Takeshi, Koichi; Kitagawa, Masahiko; Kadohira, Mutsuyo; Igimi, Shizunobu; Makino, Sou-Ichi

    2009-01-01

    Hazard analysis of Listeria monocytogenes contamination during processing of salted walleye pollock (Theragra chalcogramma) roe was performed for a seafood plant in Japan from December 2005 to February 2006. As a result, L. monocytogenes number was detected on the pallet used for transport of barrels in the salting process and one of the rollers of the roller conveyor, which rotates while in contact with the bottoms of the barrels, but was not detected in any raw materials, interim products or final products. Thus, we believe that the pallet contamination initially occurred because of insufficient washing, that it was passed on to the bottoms of the barrels and that it was then passed on the roller of the roller conveyor by cross-contamination. Therefore, it is possible that interim and final products may become contaminated by processing devices and machinery. In addition, we conducted an inoculation study designed at the 1/20 actual factory scale using interim products with or without artificial color and seeded with L. monocytogenes to observe changes in its growth. In the inoculation study, multiplication of L. monocytogenes during the salting process was not confirmed in the samples with artificial color. PMID:19194081

  15. High hydrostatic pressure processing of murine norovirus 1-contaminated oysters inhibits oral infection in STAT-1 -/- deficient female mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have previously demonstrated that high pressure processing (HPP) is effective in preventing in vitro replication of murine norovirus strain 1 (MNV-1), a human norovirus surrogate, in a monocyte cell line following extraction from MNV-1-contaminated oysters. In the present study, the efficacy of ...

  16. Treatability assessment of polycyclic aromatic hydrocarbons contaminated marine sediments using permanganate, persulfate and Fenton oxidation processes.

    PubMed

    Shih, Yu-Jen; Binh, Nguyen Thanh; Chen, Chiu-Wen; Chen, Chih-Feng; Dong, Cheng-Di

    2016-05-01

    Various chemical oxidation techniques, such as potassium permanganate (KMnO4), sodium persulfate (Na2S2O8), Fenton (H2O2/Fe(2+)), and the modified persulfate and Fenton reagents (activated by ferrous complexes), were carried out to treat marine sediments that were contaminated with polycyclic aromatic hydrocarbons (PAHs) and dredged from Kaohsiung Harbor in Taiwan. Experimental results revealed that KMnO4 was the most effective of the tested oxidants in PAH degradation. Owing to the high organic matter content in the sediment that reduced the efficiencies of Na2S2O8 and regular Fenton reactions, a large excess of oxidant was required. Nevertheless, KH2PO4, Na4P2O7 and four chelating agents (EDTA, sodium citrate, oxalic acid, and sodium oxalate) were utilized to stabilize Fe(II) in activating the Na2S2O8 and Fenton oxidations, while Fe(II)-citrate remarkably promoted the PAH degradation. Increasing the molecular weight and number of rings of PAH did not affect the overall removal efficiencies. The correlation between the effectiveness of the oxidation processes and the physicochemical properties of individual PAH was statistically analyzed. The data implied that the reactivity of PAH (electron affinity and ionization potential) affected its treatability more than did its hydrophobicity (Kow, Koc and Sw), particularly using experimental conditions under which PAHs could be effectively oxidized. PMID:26915591

  17. Implications of Using Thermal Desorption to Remediate Contaminated Agricultural Soil: Physical Characteristics and Hydraulic Processes.

    PubMed

    O'Brien, Peter L; DeSutter, Thomas M; Casey, Francis X M; Derby, Nathan E; Wick, Abbey F

    2016-07-01

    Given the recent increase in crude oil production in regions with predominantly agricultural economies, the determination of methods that remediate oil contamination and allow for the land to return to crop production is increasingly relevant. Ex situ thermal desorption (TD) is a technique used to remediate crude oil pollution that allows for reuse of treated soil, but the properties of that treated soil are unknown. The objectives of this research were to characterize TD-treated soil and to describe implications in using TD to remediate agricultural soil. Native, noncontaminated topsoil and subsoil adjacent to an active remediation site were separately subjected to TD treatment at 350°C. Soil physical characteristics and hydraulic processes associated with agricultural productivity were assessed in the TD-treated samples and compared with untreated samples. Soil organic carbon decreased more than 25% in both the TD-treated topsoil and the subsoil, and total aggregation decreased by 20% in the topsoil but was unaffected in the subsoil. The alteration in these physical characteristics explains a 400% increase in saturated hydraulic conductivity in treated samples as well as a decrease in water retention at both field capacity and permanent wilting point. The changes in soil properties identified in this study suggest that TD-treated soils may still be suitable for sustaining vegetation, although likely at a slightly diminished capacity when directly compared with untreated soils. PMID:27380094

  18. Use of jute processing wastes for treatment of wastewater contaminated with dye and other organics.

    PubMed

    Banerjee, Souvik; Dastidar, M G

    2005-11-01

    A study was conducted to examine the potential of jute processing waste (JPW) for the treatment of wastewater contaminated with dye and other organics generated from various activities associated with jute cultivation and fibre production. Adsorption studies in batch mode have been conducted using dye solution as an adsorbate and JPW as an adsorbent. A comparative adsorption study was made with standard adsorbents such as powdered and granular activated carbon (PAC and GAC, respectively). A maximum removal of 81.7% was obtained with methylene blue dye using JPW as compared to 61% using PAC and 40% using GAC under similar conditions. The adsorption potential of JPW was observed to be dependent on various parameters such as type of dye, initial dye concentration, pH and dosage of adsorbent. The batch sorption data conformed well to the Langmuir and Freundlich isotherms. However, lower BOD (33.3%) and COD (13.8%) removal from retting effluent was observed using JPW as compared to 75.6% BOD removal and 71.1% COD removal obtained with GAC. PMID:16084372

  19. Technical assessment of processes to enable recycling of low-level contaminated metal waste

    SciTech Connect

    Reimann, G.A.

    1991-10-01

    Accumulations of metal waste exhibiting low levels of radioactivity (LLCMW) have become a national burden, both financially and environmentally. Much of this metal could be considered as a resource. The Department of Energy was assigned the task of inventorying and classifying LLCMW, identifying potential applications, and applying and/or developing the technology necessary to enable recycling. One application for recycled LLCMW is high-quality canisters for permanent repository storage of high-level waste (HLW). As many as 80,000 canisters will be needed by 2035. Much of the technology needed to decontaminate LLCMW has already been developed, but no integrated process has been described, even on a pilot scale, for recycling LLCMW into HLW canisters. This report reviews practices for removal of radionuclides and for producing low carbon stainless steel. Contaminants that readily form oxides may be reduced to below de minimis levels and combined with a slag. Most of the radioactivity remaining in the ingot is concentrated in the inclusions. Radionuclides that chemically resemble the elements that comprise stainless steel can not be removed effectively. Slag compositions, current melting practices, and canister fabrication techniques were reviewed.

  20. The food processing contaminant glyoxal promotes tumour growth in the multiple intestinal neoplasia (Min) mouse model.

    PubMed

    Svendsen, Camilla; Høie, Anja Hortemo; Alexander, Jan; Murkovic, Michael; Husøy, Trine

    2016-08-01

    Glyoxal is formed endogenously and at a higher rate in the case of hyperglycemia. Glyoxal is also a food processing contaminant and has been shown to be mutagenic and genotoxic in vitro. The tumourigenic potential of glyoxal was investigated using the multiple intestinal neoplasia (Min) mouse model, which spontaneously develops intestinal tumours and is susceptible to intestinal carcinogens. C57BL/6J females were mated with Min males. Four days after mating and throughout gestation and lactation, the pregnant dams were exposed to glyoxal through drinking water (0.0125%, 0.025%, 0.05%, 0.1%) or regular tap water. Female and male offspring were housed separately from PND21 and continued with the same treatment. One group were only exposed to 0.1% glyoxal from postnatal day (PND) 21. There was no difference in the number of intestinal tumours between control and treatment groups. However, exposure to 0.1% glyoxal starting in utero and at PND21 caused a significant increase in tumour size in the small intestine for male and female mice in comparison with respective control groups. This study suggests that glyoxal has tumour growth promoting properties in the small intestine in Min mice. PMID:27288931

  1. Functional demonstration of Na+-K+-2Cl- cotransporter activity in isolated, polarized choroid plexus cells.

    PubMed

    Wu, Q; Delpire, E; Hebert, S C; Strange, K

    1998-12-01

    The function of the apical Na+-K+-2Cl- cotransporter in mammalian choroid plexus (CP) is uncertain and controversial. To investigate cotransporter function, we developed a novel dissociated rat CP cell preparation in which single, isolated cells maintain normal polarized morphology. Immunofluorescence demonstrated that in isolated cells the Na+-K+-ATPase, Na+-K+-2Cl- cotransporter, and aquaporin 1 water channel remained localized to the brush border, whereas the Cl-/HCO-3 (anion) exchanger type 2 was confined to the basolateral membrane. We utilized video-enhanced microscopy and cell volume measurement techniques to investigate cotransporter function. Application of 100 microM bumetanide caused CP cells to shrink rapidly. Elevation of extracellular K+ from 3 to 6 or 25 mM caused CP cells to swell 18 and 33%, respectively. Swelling was blocked completely by Na+ removal or by addition of 100 microM bumetanide. Exposure of CP cells to 5 mM BaCl2 induced rapid swelling that was inhibited by 100 microM bumetanide. We conclude that the CP cotransporter is constitutively active and propose that it functions in series with Ba2+-sensitive K+ channels to reabsorb K+ from cerebrospinal fluid to blood. PMID:9843718

  2. NaK Plugging Meter Design for the Feasibility Test Loops

    NASA Technical Reports Server (NTRS)

    Pearson, J. Boise; Godfroy, Thomas J.; Reid, Robert S.; Polzin, Kurt A.

    2008-01-01

    The design and predicted performance of a plugging meter for use in the measurement of NaK impurity levels are presented. The plugging meter is incorporated into a Feasibility Test Loop (FTL), which is a small pumped-NaK loop designed to enable the rapid, small-scale evaluation of techniques such as in situ purification methods and to permit the measurement of bulk material transport effects (not mechanisms) under flow conditions that are representative of a fission surface power reactor. The FTL operates at temperatures similar to those found in a reactor, with a maximum hot side temperature of 900 K and a corresponding cold side temperature of 860 K. In the plugging meter a low flow rate bypass loop is cooled until various impurities (primarily oxides) precipitate out of solution. The temperatures at which these impurities precipitate are indicative of the level of impurities in the NaK. The precipitates incrementally plug a small orifice in the bypass loop, which is detected by monitoring changes in the liquid metal flow rate.

  3. Structural analysis of the α subunit of Na(+)/K(+) ATPase genes in invertebrates.

    PubMed

    Thabet, Rahma; Rouault, J-D; Ayadi, Habib; Leignel, Vincent

    2016-01-01

    The Na(+)/K(+) ATPase is a ubiquitous pump coordinating the transport of Na(+) and K(+) across the membrane of cells and its role is fundamental to cellular functions. It is heteromer in eukaryotes including two or three subunits (α, β and γ which is specific to the vertebrates). The catalytic functions of the enzyme have been attributed to the α subunit. Several complete α protein sequences are available, but only few gene structures were characterized. We identified the genomic sequences coding the α-subunit of the Na(+)/K(+) ATPase, from the whole-genome shotgun contigs (WGS), NCBI Genomes (chromosome), Genomic Survey Sequences (GSS) and High Throughput Genomic Sequences (HTGS) databases across distinct phyla. One copy of the α subunit gene was found in Annelida, Arthropoda, Cnidaria, Echinodermata, Hemichordata, Mollusca, Placozoa, Porifera, Platyhelminthes, Urochordata, but the nematodes seem to possess 2 to 4 copies. The number of introns varied from 0 (Platyhelminthes) to 26 (Porifera); and their localization and length are also highly variable. Molecular phylogenies (Maximum Likelihood and Maximum Parsimony methods) showed some clusters constituted by (Chordata/(Echinodermata/Hemichordata)) or (Plathelminthes/(Annelida/Mollusca)) and a basal position for Porifera. These structural analyses increase our knowledge about the evolutionary events of the α subunit genes in the invertebrates. PMID:26812300

  4. Analysis of Process Gases and Trace Contaminants in Membrane-Aerated Gaseous Effluent Streams.

    NASA Technical Reports Server (NTRS)

    Coutts, Janelle L.; Lunn, Griffin Michael; Meyer, Caitlin E.

    2015-01-01

    In membrane-aerated biofilm reactors (MABRs), hollow fibers are used to supply oxygen to the biofilms and bulk fluid. A pressure and concentration gradient between the inner volume of the fibers and the reactor reservoir drives oxygen mass transport across the fibers toward the bulk solution, providing the fiber-adhered biofilm with oxygen. Conversely, bacterial metabolic gases from the bulk liquid, as well as from the biofilm, move opposite to the flow of oxygen, entering the hollow fiber and out of the reactor. Metabolic gases are excellent indicators of biofilm vitality, and can aid in microbial identification. Certain gases can be indicative of system perturbations and control anomalies, or potentially unwanted biological processes occurring within the reactor. In confined environments, such as those found during spaceflight, it is important to understand what compounds are being stripped from the reactor and potentially released into the crew cabin to determine the appropriateness or the requirement for additional mitigation factors. Reactor effluent gas analysis focused on samples provided from Kennedy Space Center's sub-scale MABRs, as well as Johnson Space Center's full-scale MABRs, using infrared spectroscopy and gas chromatography techniques. Process gases, such as carbon dioxide, oxygen, nitrogen, nitrogen dioxide, and nitrous oxide, were quantified to monitor reactor operations. Solid Phase Microextraction (SPME) GC-MS analysis was used to identify trace volatile compounds. Compounds of interest were subsequently quantified. Reactor supply air was examined to establish target compound baseline concentrations. Concentration levels were compared to average ISS concentration values and/or Spacecraft Maximum Allowable Concentration (SMAC) levels where appropriate. Based on a review of to-date results, current trace contaminant control systems (TCCS) currently on board the ISS should be able to handle the added load from bioreactor systems without the need

  5. [The probability of microbiological contamination during the collection and processing of umbilical cord blood].

    PubMed

    Zhu, Mei-Ling; Chen, Ru-Guang; Xi, Yong-Zhi; Hu, Yan-Fen; Ouyang, Ling; Zhang, Jian; Huang, Jian-Guo

    2002-08-01

    To study the pathogens incidences in cord blood and the efficiency of different detective methods, 60 samples were drawn and reserved from collected and processed cord blood, respectively. The BACTEC 9050 system, improved Martin/thioglycollate broth (22 degrees C) and thioglycollate broth (35 degrees C) were employed to detected bacteria (including fungus) at the same time. Two hundred and six cord blood serum samples were used to detect the HBV DNA and HCV RNA by molecular biology technique, HBsAg, Anti-HBC, Anti-HCV, Anti-HCMV-IgM, HTLV-1, HTLV-2, HIV-1 and HIV-2 by ELISA and RBC agglutination test were used to detect the TPHA. Results showed that using BACTEC 9050 system, the incidence of bacteria and fungus was 3.33% and 0% respectively in collected cord blood; in processed cord blood, the rates increased to 6.67% and 1.67%, respectively. The sensitivity of BACTEC 9050 was higher than that of Martin/thioglycollate broth (22 degrees C/35 degrees C) culture. In 206 serum samples, the positive rate of HBV DNA was 5.8%, HCV RNA was 2.4%, HBsAg was 2.4%, HCMV-IgM was 1.89%, HCV was 2.4% and Anti-HBC was 29.4%. In those samples that Anti-HBC was positive, the positive rate of HBV DNA was 6.7%. It was concluded that the incidences of microbiological contamination in cord blood were high. The routine culture system would lead to false negative results of obligate anaerobes. It was necessary to replace the current culture system with improved system, such as BACTEC 9050 system. The molecular biology technique would make up for the default of ELISA. PMID:12513773

  6. Manufacturing Assessment of an XeF{sub 2} In-Situ Clean Process for Mitigation of Species Cross Contamination

    SciTech Connect

    Dunn, James P.; Rolland, James L.; Lundquist, Paul; Bishop, Steve

    2008-11-03

    The residue buildup in an ion source can be energetically transported down the ion implanter beamline delivering unwanted dopants to the target area. Of particular concern are contaminants within one AMU of the target species such as {sup 50}PF{sup +} in a {sup 49}BF{sub 2}{sup +} beam causing counter-doping dose errors. Significant beam currents attributable to memory effect have been observed more than an hour after the species gas has been changed. This paper shows how Atmel Corporation, Colorado Springs, Colorado evaluated a new XeF{sub 2} in-situ clean process as an effective means of reducing the risk of species cross contamination.

  7. Molecular Characterization of the α-Subunit of Na+/K+ ATPase from the Euryhaline Barnacle Balanus improvisus Reveals Multiple Genes and Differential Expression of Alternative Splice Variants

    PubMed Central

    Lind, Ulrika; Alm Rosenblad, Magnus; Wrange, Anna-Lisa; Sundell, Kristina S.; Jonsson, Per R.; André, Carl; Havenhand, Jonathan; Blomberg, Anders

    2013-01-01

    The euryhaline bay barnacle Balanus improvisus has one of the broadest salinity tolerances of any barnacle species. It is able to complete its life cycle in salinities close to freshwater (3 PSU) up to fully marine conditions (35 PSU) and is regarded as one of few truly brackish-water species. Na+/K+ ATPase (NAK) has been shown to be important for osmoregulation when marine organisms are challenged by changing salinities, and we therefore cloned and examined the expression of different NAKs from B. improvisus. We found two main gene variants, NAK1 and NAK2, which were approximately 70% identical at the protein level. The NAK1 mRNA existed in a long and short variant with the encoded proteins differing only by 27 N-terminal amino acids. This N-terminal stretch was coded for by a separate exon, and the two variants of NAK1 mRNAs appeared to be created by alternative splicing. We furthermore showed that the two NAK1 isoforms were differentially expressed in different life stages and in various tissues of adult barnacle, i.e the long isoform was predominant in cyprids and in adult cirri. In barnacle cyprid larvae that were exposed to a combination of different salinities and pCO2 levels, the expression of the long NAK1 mRNA increased relative to the short in low salinities. We suggest that the alternatively spliced long variant of the Nak1 protein might be of importance for osmoregulation in B. improvisus in low salinity conditions. PMID:24130836

  8. Simultaneous removal of organic contaminants and heavy metals from kaolin using an upward electrokinetic soil remediation process.

    PubMed

    Wang, Jing-Yuan; Huang, Xiang-Jun; Kao, Jimmy C M; Stabnikova, Olena

    2007-06-01

    Kaolins contaminated with heavy metals, Cu and Pb, and organic compounds, p-xylene and phenanthrene, were treated with an upward electrokinetic soil remediation (UESR) process. The effects of current density, cathode chamber flushing fluid, treatment duration, reactor size, and the type of contaminants under the vertical non-uniform electric field of UESR on the simultaneous removal of the heavy metals and organic contaminants were studied. The removal efficiencies of p-xylene and phenanthrene were higher in the experiments with cells of smaller diameter or larger height, and with distilled water flow in the cathode chamber. The removal efficiency of Cu and Pb were higher in the experiments with smaller diameter or shorter height cells and 0.01M HNO(3) solution as cathode chamber flow. In spite of different conditions for removal of heavy metals and organics, it is possible to use the upward electrokinetic soil remediation process for their simultaneous removal. Thus, in the experiments with duration of 6 days removal efficiencies of phenanthrene, p-xylene, Cu and Pb were 67%, 93%, 62% and 35%, respectively. The experiment demonstrated the feasibility of simultaneous removal of organic contaminants and heavy metals from kaolin using the upward electrokinetic soil remediation process. PMID:17110023

  9. Impact of Blow/Fill/Seal process variables in determining rate of vial contamination by air dispersed microorganisms.

    PubMed

    Leo, Frank; Poisson, Patrick; Sinclair, Colin S; Tallentire, Alan

    2005-01-01

    Controlled challenges of air dispersed spores of Bacillus subtilis NCIMB 8649 have been generated in a custom-built challenge room housing a Blow/Fill/Seal machine filling filter-sterilized trypticase soy broth into 5.5 cm3 low density polyethylene vials. The effects on the rate of vial contamination of systematic changes in the process variables, rate of provision of ballooning air, delay in the application of mould vacuum and duration of transfer of the open vial, have been examined. Overall, the findings show that the conditions of vial formation can affect appreciably the rate of vial contamination from airborne spores. The indications are that heat lethality, associated with the elevated temperature required for polymer extrusion and vial formation, has a role in determining such contamination. PMID:16316067

  10. Independent technical evaluation and recommendations for contaminated groundwater at the department of energy office of legacy management Riverton processing site

    SciTech Connect

    Looney, Brain B.; Denham, Miles E.; Eddy-Dilek, Carol A.

    2014-04-01

    The U.S. Department of Energy Office of Legacy Management (DOE-LM) manages the legacy contamination at the Riverton, WY, Processing Site – a former uranium milling site that operated from 1958 to 1963. The tailings and associated materials were removed in 1988-1989 and contaminants are currently flushing from the groundwater. DOE-LM commissioned an independent technical team to assess the status of the contaminant flushing, identify any issues or opportunities for DOE-LM, and provide key recommendations. The team applied a range of technical frameworks – spatial, temporal, hydrological and geochemical – in performing the evaluation. In each topic area, an in depth evaluation was performed using DOE-LM site data (e.g., chemical measurements in groundwater, surface water and soil, water levels, and historical records) along with information collected during the December 2013 site visit (e.g., plant type survey, geomorphology, and minerals that were observed, collected and evaluated).

  11. ALTERNATIVE BIOLOGICAL TREATMENT PROCESSES FOR REMEDIATION OF CREOSOTE-CONTAMINATED MATERIALS: BENCH-SCALE TREATABILITY STUDIES

    EPA Science Inventory

    Bench-scale biotreatability studies were performed to determine the most effective of two bioremediation application strategies to ameliorate creosote and pentachlorophenol (PCP) contaminated soils present at the American Creosote Works Superfund site, Pensacola, Florida: olid-ph...

  12. Microbial interactions with organic contaminants in soil: definitions, processes and measurement.

    PubMed

    Semple, Kirk T; Doick, Kieron J; Wick, Lukas Y; Harms, Hauke

    2007-11-01

    There has been and continues to be considerable scientific interest in predicting bioremediation rates and endpoints. This requires the development of chemical techniques capable of reliably predicting the bioavailability of organic compounds to catabolically active soil microbes. A major issue in understanding the link between chemical extraction and bioavailability is the problem of definition; there are numerous definitions, of varying degrees of complexity and relevance, to the interaction between organic contaminants and microorganisms in soil. The aim of this review is to consider the bioavailability as a descriptor for the rate and extent of biodegradation and, in an applied sense, bioremediation of organic contaminants in soil. To address this, the review will (i) consider and clarify the numerous definitions of bioavailability and discuss the usefulness of the term 'bioaccessibility'; (ii) relate definition to the microbiological and chemical measurement of organic contaminants' bioavailability in soil, and (iii) explore the mechanisms employed by soil microorganisms to attack organic contaminants in soil. PMID:17881105

  13. Controlling Transport Processes in Groundwater Contamination in the North Coast Karst Aquifer of Puerto Rico

    NASA Astrophysics Data System (ADS)

    Padilla, I. Y.; Steele, K.

    2008-05-01

    The karst aquifer of the North Coast of Puerto Rico represents a significant source of water for drinking purposes, as well as ecosystem sustainability. The same characteristics making this aquifer the most productive in the island, fast infiltration and rapid flow in karst conduits, make the aquifers vulnerable highly vulnerable to contamination. Once in the ground water, organic contaminants move through the karst aquifers by complex pathways dictated by system characteristics and flow regimes. Ground water flow in karst aquifers is subscribed to two types of flow systems: conduit flow and diffuse flow. Transport in conduit-flow dominated systems tends to convey solutes rapidly through the system to a discharge or point without much attenuation. Transport in diffuse- flow systems, on the other hand, causes significant solute retardation and serves as a long-term source of contamination. Although it is common to attribute one type of predominant flow regime, most carbonate aquifers are characterized by a mixture of both flow systems. The north coast aquifer of Puerto Rico has been impacted by a large number of contaminates sites. During the last 25 years, 10 Superfund sites have been declared in the zone and others are being evaluated for inclusion in the National Priority List. The work presented herein addresses the potential impact of these sites on the extent of contamination and discusses the transport mechanisms affecting the transport and persistence of organic contaminants in the north coast aquifer of Puerto Rico. Preliminary evaluation indicates that fate and transport of these contaminants is controlled by a combinations of conduit- and diffuse-flow mechanisms, where conduits tend to concentrate water and contaminants and convey it rapidly or to "trapping" diffusive-flow zones of smaller pore-size zones.

  14. SEMICONDUCTOR TECHNOLOGY A new cleaning process for the metallic contaminants on a post-CMP wafer's surface

    NASA Astrophysics Data System (ADS)

    Baohong, Gao; Yuling, Liu; Chenwei, Wang; Yadong, Zhu; Shengli, Wang; Qiang, Zhou; Baimei, Tan

    2010-10-01

    This paper presents a new cleaning process using boron-doped diamond (BDD) film anode electrochemical oxidation for metallic contaminants on polished silicon wafer surfaces. The BDD film anode electrochemical oxidation can efficiently prepare pyrophosphate peroxide, pyrophosphate peroxide can oxidize organic contaminants, and pyrophosphate peroxide is deoxidized into pyrophosphate. Pyrophosphate, a good complexing agent, can form a metal complex, which is a structure consisting of a copper ion, bonded to a surrounding array of two pyrophosphate anions. Three polished wafers were immersed in the 0.01 mol/L CuSO4 solution for 2 h in order to make comparative experiments. The first one was cleaned by pyrophosphate peroxide, the second by RCA (Radio Corporation of America) cleaning, and the third by deionized (DI) water. The XPS measurement result shows that the metallic contaminants on wafers cleaned by the RCA method and by pyrophosphate peroxide is less than the XPS detection limits of 1 ppm. And the wafer's surface cleaned by pyrophosphate peroxide is more efficient in removing organic carbon residues than RCA cleaning. Therefore, BDD film anode electrochemical oxidation can be used for microelectronics cleaning, and it can effectively remove organic contaminants and metallic contaminants in one step. It also achieves energy saving and environmental protection.

  15. Shallow Structure Characterization at a Groundwater Contamination Site: Seismic Processing and Tomographic Inversion

    NASA Astrophysics Data System (ADS)

    Fradelizio, G.; Gao, F.; Levander, A.; Zelt, C. A.

    2005-12-01

    In order to image the heterogeneities in a shallow (less then 20 meters) buried paleo-channel where groundwater is severely contaminated by trichloroethylene (TCE), two vertical seismic profiles (VSP) and a seismic profile between the two boreholes (VSP-surface) were acquired. The surficial lithology consists of a mix of Quaternary sands and gravels overlying an incised clay layer acting as structural/stratigraphic trap for the polluting DNAPLs (dense nonaqueous phase liquids). The high-resolution data were processed following a standard seismic processing scheme, and inverted using traveltime and waveform tomography methods. The tomographic velocity models were subsequently utilized to depth migrate the VSP-surface data, both post-stack and pre-stack using explicit finite-difference extrapolators. In addition, Q values were estimated for the area of interest, directly from the imaginary part of the tomographic velocities, and using spectral ratio methods on the VSP data. Since the shallow structures can be characterized mechanically to some degree in terms of physical properties such as seismic velocity, the reflection seismic migrated images can be directly compared to the waveform tomography velocity models, given that the two methods produce results with comparable resolution. Generally, a reasonably good agreement exists between the results of the two different methodologies, keeping in mind that the migrated image shows impedance contrasts, whereas the waveform tomography measures velocity fluctuations directly. Both seismic and tomography images suggest that the geological structure in the target area is considerably more complex and heterogeneous than a simple layer of alluvium over an eroded clay layer, as is also suggested by lithology logs. The heterogeneity in the target area suggests that a conventional reflection processing sequence including CMP stacking and post-stack migration may be compromised because of large lateral velocity variations. As we

  16. Multiple-tracer tests for contaminant transport process identification in saturated municipal solid waste

    SciTech Connect

    Woodman, N.D. Rees-White, T.C.; Stringfellow, A.M.; Beaven, R.P.; Hudson, A.P.

    2015-04-15

    Highlights: • Multiple tracers were applied to saturated MSW to test dual-porosity properties. • Lithium demonstrated to be non-conservative as a tracer. • 260 mm diameter column too small to test transport properties of MSW. • The classical advection-dispersion mode was rejected due to high dispersivity. • Characteristic diffusion times did not vary with the tracer. - Abstract: Two column tests were performed in conditions emulating vertical flow beneath the leachate table in a biologically active landfill to determine dominant transport mechanisms occurring in landfills. An improved understanding of contaminant transport process in wastes is required for developing better predictions about potential length of the long term aftercare of landfills, currently measured in timescales of centuries. Three tracers (lithium, bromide and deuterium) were used. Lithium did not behave conservatively. Given that lithium has been used extensively for tracing in landfill wastes, the tracer itself and the findings of previous tests which assume that it has behaved conservatively may need revisiting. The smaller column test could not be fitted with continuum models, probably because the volume of waste was below a representative elemental volume. Modelling compared advection-dispersion (AD), dual porosity (DP) and hybrid AD–DP models. Of these models, the DP model was found to be the most suitable. Although there is good evidence to suggest that diffusion is an important transport mechanism, the breakthrough curves of the different tracers did not differ from each other as would be predicted based on the free-water diffusion coefficients. This suggested that solute diffusion in wastes requires further study.

  17. Sobol‧ sensitivity analysis of NAPL-contaminated aquifer remediation process based on multiple surrogates

    NASA Astrophysics Data System (ADS)

    Luo, Jiannan; Lu, Wenxi

    2014-06-01

    Sobol‧ sensitivity analyses based on different surrogates were performed on a trichloroethylene (TCE)-contaminated aquifer to assess the sensitivity of the design variables of remediation duration, surfactant concentration and injection rates at four wells to remediation efficiency First, the surrogate models of a multi-phase flow simulation model were constructed by applying radial basis function artificial neural network (RBFANN) and Kriging methods, and the two models were then compared. Based on the developed surrogate models, the Sobol‧ method was used to calculate the sensitivity indices of the design variables which affect the remediation efficiency. The coefficient of determination (R2) and the mean square error (MSE) of these two surrogate models demonstrated that both models had acceptable approximation accuracy, furthermore, the approximation accuracy of the Kriging model was slightly better than that of the RBFANN model. Sobol‧ sensitivity analysis results demonstrated that the remediation duration was the most important variable influencing remediation efficiency, followed by rates of injection at wells 1 and 3, while rates of injection at wells 2 and 4 and the surfactant concentration had negligible influence on remediation efficiency. In addition, high-order sensitivity indices were all smaller than 0.01, which indicates that interaction effects of these six factors were practically insignificant. The proposed Sobol‧ sensitivity analysis based on surrogate is an effective tool for calculating sensitivity indices, because it shows the relative contribution of the design variables (individuals and interactions) to the output performance variability with a limited number of runs of a computationally expensive simulation model. The sensitivity analysis results lay a foundation for the optimal groundwater remediation process optimization.

  18. [Study on rapid analysis method of pesticide contamination in processed foods by GC-MS and GC-FPD].

    PubMed

    Kobayashi, Maki; Otsuka, Kenji; Tamura, Yasuhiro; Tomizawa, Sanae; Kamijo, Kyoko; Iwakoshi, Keiko; Sato, Chizuko; Nagayama, Toshihiro; Takano, Ichiro

    2011-01-01

    A simple and rapid method using GC-MS and GC-FPD for the determination of pesticide contamination in processed food has been developed. Pesticides were extracted from a sample with ethyl acetate in the presence of anhydrous sodium sulfate, then cleaned up with a combination of mini-columns, such as macroporous diatomaceous earth, C18, GCB (graphite carbon black) and PSA. Recovery tests of 57 pesticides (known to be toxic or harmful) from ten kinds of processed foods (butter, cheese, corned beef, dried shrimp, frozen Chinese dumplings, grilled eels, instant noodles, kimchi, retort-packed curry and wine) were performed, and the recovery rates were mostly between 70% and 120%. This method can be used to judge whether or not processed foods are contaminated with pesticides at potentially harmful levels. PMID:21873813

  19. Influence of salinity on the localization of Na+/K +-ATPase, Na+/K+/2Cl- cotransporter (NKCC) and CFTR anion channel in chloride cells of the Hawaiian goby (Stenogobius hawaiiensis)

    USGS Publications Warehouse

    McCormick, S.D.; Sundell, K.; Bjornsson, Bjorn Thrandur; Brown, C.L.; Hiroi, J.

    2003-01-01

    Na+/K+-ATPase, Na+/K+/2Cl- cotransporter (NKCC) and cystic fibrosis transmembrane conductance regulator (CFTR) are the three major transport proteins thought to be involved in chloride secretion in teleost fish. If this is the case, the levels of these transporters should be high in chloride cells of seawater-acclimated fish. We therefore examined the influence of salinity on immunolocalization of Na +/K+-ATPase, NKCC and CFTR in the gills of the Hawaiian goby (Stenogobius hawaiiensis). Fish were acclimated to freshwater and 20??? and 30??? seawater for 10 days. Na+/K +-ATPase and NKCC were localized specifically to chloride cells and stained throughout most of the cell except for the nucleus and the most apical region, indicating a basolateral/tubular distribution. All Na+/K +-ATPase-positive chloride cells were also positive for NKCC in all salinities. Salinity caused a slight increase in chloride cell number and size and a slight decrease in staining intensity for Na+/K +-ATPase and NKCC, but the basic pattern of localization was not altered. Gill Na+/K+-ATPase activity was also not affected by salinity. CFTR was localized to the apical surface of chloride cells, and only cells staining positive for Na+/K+-ATPase were CFTR-positive. CFTR-positive cells greatly increased in number (5-fold), area stained (53%) and intensity (29%) after seawater acclimation. In freshwater, CFTR immunoreactivity was light and occurred over a broad apical surface on chloride cells, whereas in seawater there was intense immunoreactivity around the apical pit (which was often punctate in appearance) and a light subapical staining. The results indicate that Na+/K +-ATPase, NKCC and CFTR are all present in chloride cells and support current models that all three are responsible for chloride secretion by chloride cells of teleost fish.

  20. Status of Kilowatt-Class Stirling Power Conversion Using a Pumped NaK Loop for Thermal Input

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.; Geng, Steven M.; Robbie, Malcolm G.

    2010-01-01

    Free-piston Stirling power conversion has been identified as a viable option for potential Fission Surface Power (FSP) systems on the Moon and Mars. Proposed systems consist of two or more Stirling convertors, in a dual-opposed configuration, coupled to a low-temperature uranium-dioxide-fueled, liquid-metal-cooled reactor. To reduce developmental risks associated with liquid-metal loop integration, a test rig has been built to evaluate the performance of a pair of 1-kW free-piston Stirling convertors using a pumped sodium-potassium (NaK) loop for thermal energy input. Baseline performance maps have been generated at the Glenn Research Center (GRC) for these 1-kW convertors operating with an electric heat source. Each convertor was then retrofitted with a custom-made NaK heater head and integrated into a pumped NaK system at the Marshall Space Flight Center (MSFC). This paper documents baseline testing at GRC as well as the progress made in integrating the Stirling convertors into the pumped NaK loop.

  1. Dioctahedral smectite reactions at elevated temperatures: Effects of K-availability, Na/K ratio and ionic strength

    USGS Publications Warehouse

    Whitney, G.

    1992-01-01

    Hydrothermal experiments were conducted to measure the effects of K availability, Na/K ratio and ionic strength in chloride solutions on the rate and extent of the reaction of smectite to interstratified illite/smectite. The < 2 ??m fraction of a bentonite was treated hydrothermally at temperatures of 200, 250, 300, 350, 400 and 450??C for run times of up to 30 days in the presence of 0.33, 0.66 and 1.00 equivalents of K per O10(OH)2. The effect of K-content on reaction progress is dramatic at low (0.33 eq.) K concentrations, but diminishes above a concentration of 0.66 equivalents. The effect of K-content is also more important at lower temperatures than at higher temperatures. Addition of K above that required to satisfy the cation exchange capacity of the smectite reduced the amount of chlorite byproduct and produced authigenic K-feldspar at the highest K-concentration. Similar experiments were run using Na/K equivalent ratios of 0 to 25 and total solution molalities of 0 to 3.75 molal. Because these experiments were small fixed-volume experiments, it was necessary to vary two of the three key variables (K-content, Na/K ratio, ionic strength simultaneously. The data suggest, however, that K-content has a much stronger effect than either Na/K ratio or ionic strength on illitization reaction progress. ?? 1992.

  2. Furosemide-induced airway relaxation in guinea pigs: relation to Na-K-2Cl cotransporter function.

    PubMed

    Lavallee, S L; Iwamoto, L M; Claybaugh, J R; Dressel, M V; Sato, A K; Nakamura, K T

    1997-07-01

    This study tested the hypothesis that airway relaxation to furosemide is mediated via the Na-K-2Cl cotransporter. If this mechanism exists in airway smooth muscle like in vascular smooth muscle, changes in airway relaxation should be associated with changes in Na-K-2Cl cotransporter function, and both should be substrate dependent. Tracheal rings from newborn guinea pigs were bathed in standard (STD) or varying low Cl- concentration ([Cl-]) N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES). Isometric relaxation to 300 microM furosemide or 10(-8) to 10(-5) M salbutamol was measured. Airway segments were incubated with rubidium-86 (86Rb) in STD or varying low [Cl-] HEPES, with and without 300 microM furosemide or 25 microM salbutamol. Furosemide was unable to reduce 86Rb uptake at 10 mM [Cl-], although relaxation was still observed in 10 mM [Cl-]. Salbutamol did not affect 86Rb uptake. This study demonstrated that there is a furosemide-sensitive Na-K-2Cl cotransporter in newborn guinea pig trachea. However, the effect of furosemide on cotransporter function did not always directly correspond to differences in relaxation, suggesting that the Na-K-2Cl cotransporter may play a major, but not exclusive, role in furosemide-induced airway relaxation. PMID:9252558

  3. Stabilization/solidification of mercury-contaminated waste ash using calcium sodium phosphate (CNP) and magnesium potassium phosphate (MKP) processes.

    PubMed

    Cho, Jae Han; Eom, Yujin; Lee, Tai Gyu

    2014-08-15

    This study examined the stabilization and solidification (S/S) of mercury (Hg)-contaminated waste ash generated from an industrial waste incinerator using chemically bonded phosphate ceramic (CBPC) technology. A magnesium potassium phosphate (MKP; MgKPO4 · 6H2O) ceramic, fabricated from MgO and KH2PO4, and a calcium sodium phosphate (CNP; CaNaPO4) ceramic, fabricated from CaO and Na2HPO4, were used as solidification binders in the CBPC process, and Na2S or FeS was added to each solidification binder to stabilize the Hg-contaminated waste ash. The S/S processes were conducted under various operating conditions (based on the solidification binder and stabilization reagent, stabilization reagent dosage, and waste loading ratio), and the performance characteristics of the S/S sample under each operating condition were compared, including the Hg leaching value and compressive strength. The Hg leaching value of untreated Hg-contaminated waste ash was 231.3 μg/L, whereas the S/S samples treated using the MKP and CNP processes exhibited Hg leaching values below the universal treatment standard (UTS) limit (25 μg/L). Although the compressive strengths of the S/S samples decreased as the sulfide dosage and waste loading ratio were increased, most of the S/S samples fabricated by the MKP and CNP processes exhibited good mechanical properties. PMID:24997263

  4. Integrated system for gathering, processing, and reporting data relating to site contamination

    DOEpatents

    Long, Delmar D.; Goldberg, Mitchell S.; Baker, Lorie A.

    1997-01-01

    An integrated screening system comprises an intrusive sampling subsystem, a field mobile laboratory subsystem, a computer assisted design/geographical information subsystem, and a telecommunication linkup subsystem, all integrated to provide synergistically improved data relating to the extent of site soil/groundwater contamination. According to the present invention, data samples related to the soil, groundwater or other contamination of the subsurface material are gathered and analyzed to measure contaminants. Based on the location of origin of the samples in three-dimensional space, the analyzed data are transmitted to a location display. The data from analyzing samples and the data from the locating the origin are managed to project the next probable sample location. The next probable sample location is then forwarded for use as a guide in the placement of ensuing sample location, whereby the number of samples needed to accurately characterize the site is minimized.

  5. Integrated system for gathering, processing, and reporting data relating to site contamination

    DOEpatents

    Long, D.D.; Goldberg, M.S.; Baker, L.A.

    1997-11-11

    An integrated screening system comprises an intrusive sampling subsystem, a field mobile laboratory subsystem, a computer assisted design/geographical information subsystem, and a telecommunication linkup subsystem, all integrated to provide synergistically improved data relating to the extent of site soil/groundwater contamination. According to the present invention, data samples related to the soil, groundwater or other contamination of the subsurface material are gathered and analyzed to measure contaminants. Based on the location of origin of the samples in three-dimensional space, the analyzed data are transmitted to a location display. The data from analyzing samples and the data from the locating the origin are managed to project the next probable sample location. The next probable sample location is then forwarded for use as a guide in the placement of ensuing sample location, whereby the number of samples needed to accurately characterize the site is minimized. 10 figs.

  6. Control of anisotropic interactions with microwaves in ultracold NaK molecules

    NASA Astrophysics Data System (ADS)

    Yan, Zoe; Loh, Huanqian; Park, Jee Woo; Will, Sebastian; Zwierlein, Martin

    2016-05-01

    Ultracold polar molecules offer long range anisotropic interactions, which can provide access to novel phases of condensed matter physics. The recent creation of fermionic NaK polar molecules in the ground hyperfine-rovibronic state, which is chemically stable, demonstrates an important step towards the study of new dipolar physics. To engineer dipolar interactions between molecules with large electric dipole moments, one can apply microwaves to mix the lowest and first excited rotational states. Hyperfine interaction in the first excited rotational state mixes nuclear spin and rotation, leading to states with rich character, which we map out by performing microwave spectroscopy. The admixed hyperfine character serves as a tool to engineer wide ranges of ``magic'' trap polarization angles, at which the lowest and first excited rotational states have matching polarizabilities. Finally, we demonstrate that we can access large dipole moments by coherently dressing the molecules with microwaves.

  7. Effect of various Na/K ratios in low-salinity well water on growth performance and physiological response of Pacific white shrimp Litopenaeus vannamei

    NASA Astrophysics Data System (ADS)

    Liu, Hongyu; Tan, Beiping; Yang, Jinfang; Lin, Yingbo; Chi, Shuyan; Dong, Xiaohui; Yang, Qihui

    2014-09-01

    To investigate the influence of sodium to potassium (Na/K) ratios on the growth performance and physiological response of the Pacific white shrimp ( Litopenaeus vananmei), various concentrations of KCl were added to low-salinity well water (salinity 4) in an 8-week culture trial. Six treatments with Na/K ratios of 60:1, 42:1, 33:1, 23:1, 17:1, and 14:1 were replicated in triplicate. The highest weight-gain rate (3 506±48)% and survival rate (89.38±0.88)% was observed in well water with Na/K ratios of 23:1 and 42:1, respectively, while the feed conversion ratio (1.02±0.01), oxygen consumption, and ammonia-N excretion rate was the lowest in the medium with a Na/K ratio of 23:1. Gill Na+-K+-ATPase activity, as an indicator of osmoregulation, peaked in the treatment where the Na/K ratio was 17:1. The total hemocyte count, respiratory burst, and immune-related enzyme activities (ALP, LSZ, PO, and SOD) of L. vananmei were affected significantly by Na/K ratios ( P<0.05). After challenged with Vibrio harveyi, the cumulative mortality of shrimp reared in a Na/K ratio of 23:1 (30±14.14)% was significantly lower than the control (75±7.07)%. In conclusion, the addition of K+ to low-salinity well water in L. vannamei cultures is feasible. Na/K ratios ranging from 23:1 to 33:1 might improve survival and growth. Immunity and disease resistance are also closely related to the Na/K ratio of the low-salinity well water. The findings may contribute to the development of more efficient K + remediation strategies for L. vananmei culture in low-salinity well water.

  8. Toxicological benchmarks for potential contaminants of concern for effects on soil and litter invertebrates and heterotrophic process

    SciTech Connect

    Will, M.E.; Suter, G.W. II

    1995-09-01

    An important step in ecological risk assessments is screening the chemicals occur-ring on a site for contaminants of potential concern. Screening may be accomplished by comparing reported ambient concentrations to a set of toxicological benchmarks. Multiple endpoints for assessing risks posed by soil-borne contaminants to organisms directly impacted by them have been established. This report presents benchmarks for soil invertebrates and microbial processes and addresses only chemicals found at United States Department of Energy (DOE) sites. No benchmarks for pesticides are presented. After discussing methods, this report presents the results of the literature review and benchmark derivation for toxicity to earthworms (Sect. 3), heterotrophic microbes and their processes (Sect. 4), and other invertebrates (Sect. 5). The final sections compare the benchmarks to other criteria and background and draw conclusions concerning the utility of the benchmarks.

  9. Dependence of Na-K pump current on internal Na+ in mammalian cardiac myocytes.

    PubMed

    Mogul, D J; Singer, D H; Ten Eick, R E

    1990-08-01

    Na-K pump current (Ipump) is a function of the intracellular Na+ concentration [( Na+]i). We examined the quantitative relationship between Ipump and [Na+]i in isolated guinea pig ventricular myocytes under steady-state conditions. [Na+]i was controlled and "clamped" at several selected concentrations using wide-tipped pipette microelectrodes, and membrane current was measured using the whole cell patch voltage-clamp technique. Ipump generated at a holding potential of -40 mV was determined by measuring the change in steady-state holding current before and during exposure to dihydroouabain (1 mM); Ipump was measured at 11 levels of [Na+]i ranging from 0 to 80 mM (n = 63) with only one measurement per cell and normalized to cell capacitance to account for differences between myocytes in sarcolemmal surface area. Ipump exhibited a nonlinear dependence on [Na+]i; a Hill analysis of the relationship yielded a half-maximal [Na+]i for pump stimulation of 43.2 mM and a Hill coefficient of 1.53. An alternative analysis of the experimental data was performed assuming that occupation of three internal binding sites by Na+ is required for enzyme turnover. Regression analysis gave the best fit when only two different binding affinities (KD) are postulated. The values are KD1 = 1 mM, KD2 = KD3 = 29 mM. From the analysis using the latter model, the level of [Na+]i at which Ipump saturated closely approximated the theoretical saturation level calculated from published estimates of pump turnover rate and density. The maximal sensitivity of the Na-K pump to changes in [Na+]i occurs when internal [Na+] is within the range for the normal resting physiological level. PMID:2167023

  10. Processes affecting geochemistry and contaminant movement in the middle Claiborne aquifer of the Mississippi embayment aquifer system

    USGS Publications Warehouse

    Katz, Brian G.; Kingsbury, James A.; Welch, Heather L.; Tollett, Roland W.

    2012-01-01

    Groundwater chemistry and tracer-based age data were used to assess contaminant movement and geochemical processes in the middle Claiborne aquifer (MCA) of the Mississippi embayment aquifer system. Water samples were collected from 30 drinking-water wells (mostly domestic and public supply) and analyzed for nutrients, major ions, pesticides, volatile organic compounds (VOCs), and transient age tracers (chlorofluorocarbons, tritium and helium-3, and sulfur hexafluoride). Redox conditions are highly variable throughout the MCA. However, mostly oxic groundwater with low dissolved solids is more vulnerable to nitrate contamination in the outcrop areas east of the Mississippi River in Mississippi and west Tennessee than in mostly anoxic groundwater in downgradient areas in western parts of the study area. Groundwater in the outcrop area was relatively young (apparent age of less than 40 years) with significantly (p 50 m depth) indicated contaminant movement from shallow parts of the aquifer into deeper oxic zones. Given the persistence of nitrate in young oxic groundwater that was recharged several decades ago, and the lack of a confining unit, the downward movement of young contaminated water may result in higher nitrate concentrations over time in deeper parts of the aquifer containing older oxic water.

  11. CONTAMINANT-ORGANIC COMPLEXES, THEIR STRUCTURE AND ENERGETICS IN SURFACE DECONTAMINATION PROCESSES

    EPA Science Inventory

    The DOE must decontaminated and decommission a large number of surplus facilities. At present there about 7,000 contaminated facilities that require deactivation and decommissioning. A major need associated with this effort is improvement of metal surface decontamination. The DO...

  12. REMOVAL OF ORGANIC CCL CONTAMINANTS FROM DRINKING WATERS BY GAC, AIR STRIPPING, AND MEMBRANE PROCESSES

    EPA Science Inventory

    The 1996 amendments to the Safe Drinking Water Act (SWDA) require the US Environmental Protection Agency (USEPA) to establish a list of unregulated microbiological and chemical contaminants to aid in priority-setting for the Agency's drinking water program. This list, known as t...

  13. TREATMENT OF PERCHLORATE CONTAMINATED WATER USING A COMBINED BIOTIC/ABIOTIC PROCESS

    EPA Science Inventory

    The results from the project will allow us to evaluate both in-situ remediation and ex-situ treatment of perchlorate contaminated waters. A project duration of three years is proposed with a first-year budget of $69,442; a budget of approximately $70,000 per year i...

  14. Value Added Processing of Aflatoxin Contaminated Peanut Meal: Aflatoxin Sequestration During Protein Extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of a bentonite clay, Astra-Ben 20A (AB20A), to sequester aflatoxin from contaminated (~110 ppb) peanut meal during protein extraction was studied. Aqueous peanut meal dispersions (10% w/w) were prepared varying pH, temperature, enzymatic hydrolysis conditions, and concentrations of AB2...

  15. Temporal variations in parameters reflecting terminal-electron-accepting processes in an aquifer contaminated with waste fuel and chlorinated solvents

    USGS Publications Warehouse

    McGuire, Jennifer T.; Smith, Erik W.; Long, David T.; Hyndman, David W.; Haack, Sheridan K.; Klug, Michael J.; Velbel, Michael A.

    2000-01-01

    A fundamental issue in aquifer biogeochemistry is the means by which solute transport, geochemical processes, and microbiological activity combine to produce spatial and temporal variations in redox zonation. In this paper, we describe the temporal variability of TEAP conditions in shallow groundwater contaminated with both waste fuel and chlorinated solvents. TEAP parameters (including methane, dissolved iron, and dissolved hydrogen) were measured to characterize the contaminant plume over a 3-year period. We observed that concentrations of TEAP parameters changed on different time scales and appear to be related, in part, to recharge events. Changes in all TEAP parameters were observed on short time scales (months), and over a longer 3-year period. The results indicate that (1) interpretations of TEAP conditions in aquifers contaminated with a variety of organic chemicals, such as those with petroleum hydrocarbons and chlorinated solvents, must consider additional hydrogen-consuming reactions (e.g., dehalogenation); (2) interpretations must consider the roles of both in situ (at the sampling point) biogeochemical and solute transport processes; and (3) determinations of microbial communities are often necessary to confirm the interpretations made from geochemical and hydrogeological measurements on these processes.

  16. Contaminants from Cretaceous Black Shale Part 1: Natural weathering processes controlling contaminant cycling in Mancos Shale, southwestern United States, with emphasis on salinity and selenium

    USGS Publications Warehouse

    Tuttle, Michele L.W.; Fahy, Juli W.; Elliott, John G.; Grauch, Richard I.; Stillings, Lisa L.

    2013-01-01

    Soils derived from black shale can accumulate high concentrations of elements of environmental concern, especially in regions with semiarid to arid climates. One such region is the Colorado River basin in the southwestern United States where contaminants pose a threat to agriculture, municipal water supplies, endangered aquatic species, and water-quality commitments to Mexico. Exposures of Cretaceous Mancos Shale (MS) in the upper basin are a major contributor of salinity and selenium in the Colorado River. Here, we examine the roles of geology, climate, and alluviation on contaminant cycling (emphasis on salinity and Se) during weathering of MS in a Colorado River tributary watershed. Stage I (incipient weathering) began perhaps as long ago as 20 ka when lowering of groundwater resulted in oxidation of pyrite and organic matter. This process formed gypsum and soluble organic matter that persist in the unsaturated, weathered shale today. Enrichment of Se observed in laterally persistent ferric oxide layers likely is due to selenite adsorption onto the oxides that formed during fluctuating redox conditions at the water table. Stage II weathering (pedogenesis) is marked by a significant decrease in bulk density and increase in porosity as shale disaggregates to soil. Rainfall dissolves calcite and thenardite (Na2SO4) at the surface, infiltrates to about 1 m, and precipitates gypsum during evaporation. Gypsum formation (estimated 390 kg m−2) enriches soil moisture in Na and residual SO4. Transpiration of this moisture to the surface or exposure of subsurface soil (slumping) produces more thenardite. Most Se remains in the soil as selenite adsorbed to ferric oxides, however, some oxidizes to selenate and, during wetter conditions is transported with soil moisture to depths below 3 m. Coupled with little rainfall, relatively insoluble gypsum, and the translocation of soluble Se downward, MS landscapes will be a significant nonpoint source of salinity and Se to the

  17. Milk contamination and resistance to processing conditions determine the fate of Lactococcus lactis bacteriophages in dairies.

    PubMed

    Madera, Carmen; Monjardín, Cristina; Suárez, Juan E

    2004-12-01

    Milk contamination by phages, the susceptibility of the phages to pasteurization, and the high levels of resistance to phage infection of starter strains condition the evolution dynamics of phage populations in dairy environments. Approximately 10% (83 of 900) of raw milk samples contained phages of the quasi-species c2 (72%), 936 (24%), and P335 (4%). However, 936 phages were isolated from 20 of 24 (85%) whey samples, while c2 was detected in only one (4%) of these samples. This switch may have been due to the higher susceptibility of c2 to pasteurization (936-like phages were found to be approximately 35 times more resistant than c2 strains to treatment of contaminated milk in a plate heat exchanger at 72 degrees C for 15 s). The restriction patterns of 936-like phages isolated from milk and whey were different, indicating that survival to pasteurization does not result in direct contamination of the dairy environment. The main alternative source of phages (commercial bacterial starters) does not appear to significantly contribute to phage contamination. Twenty-four strains isolated from nine starter formulations were generally resistant to phage infection, and very small progeny were generated upon induction of the lytic cycle of resident prophages. Thus, we postulate that a continuous supply of contaminated milk, followed by pasteurization, creates a factory environment rich in diverse 936 phage strains. This equilibrium would be broken if a particular starter strain turned out to be susceptible to infection by one of these 936-like phages, which, as a consequence, became prevalent. PMID:15574937

  18. Processing-Dependent and Clonal Contamination Patterns of Listeria monocytogenes in the Cured Ham Food Chain Revealed by Genetic Analysis.

    PubMed

    Morganti, Marina; Scaltriti, Erika; Cozzolino, Paolo; Bolzoni, Luca; Casadei, Gabriele; Pierantoni, Marco; Foni, Emanuela; Pongolini, Stefano

    2016-02-01

    The quantitative and qualitative patterns of environmental contamination by Listeria monocytogenes were investigated in the production chain of dry-cured Parma ham. Standard arrays of surfaces were sampled in processing facilities during a single visit per plant in the three compartments of the food chain, i.e., ham production (19 plants) and postproduction, which was divided into deboning (43 plants) and slicing (25 plants) steps. The numbers of sampled surfaces were 384 in ham production, with 25 positive for L. monocytogenes, and 1,084 in postproduction, with 83 positives. Statistical analysis of the prevalence of contaminated surfaces showed that in ham production, contamination was higher at the beginning of processing and declined significantly toward the end, while in postproduction, prevalence rose toward the end of processing. Prevalence was higher in the deboning facilities than in slicing facilities and was dependent on the type of surface (floor/drainage > clothing > equipment). The qualitative pattern of contamination was investigated through an analysis of the survey isolates and a set of isolates derived from routine monitoring, including longitudinal isolations. Pulsed-field gel electrophoresis (PFGE) and whole-genome single-nucleotide polymorphism (SNP) analysis revealed a remarkable clonality of L. monocytogenes within plants, with the detection of 16 plant-specific clones out of 17 establishments with multiple isolates. Repeated detections of clonal isolates >6 months apart were also observed. Six was the maximum number of between-isolate differences in core SNPs observed within these clones. Based on the same six-SNP threshold, three clusters of clonal isolates, shared by six establishments, were also identified. The spread of L. monocytogenes within and between plants, as indicated by its clonal behavior, is a matter of concern for the hygienic management of establishments. PMID:26590278

  19. Processing-Dependent and Clonal Contamination Patterns of Listeria monocytogenes in the Cured Ham Food Chain Revealed by Genetic Analysis

    PubMed Central

    Morganti, Marina; Scaltriti, Erika; Cozzolino, Paolo; Bolzoni, Luca; Casadei, Gabriele; Pierantoni, Marco; Foni, Emanuela

    2015-01-01

    The quantitative and qualitative patterns of environmental contamination by Listeria monocytogenes were investigated in the production chain of dry-cured Parma ham. Standard arrays of surfaces were sampled in processing facilities during a single visit per plant in the three compartments of the food chain, i.e., ham production (19 plants) and postproduction, which was divided into deboning (43 plants) and slicing (25 plants) steps. The numbers of sampled surfaces were 384 in ham production, with 25 positive for L. monocytogenes, and 1,084 in postproduction, with 83 positives. Statistical analysis of the prevalence of contaminated surfaces showed that in ham production, contamination was higher at the beginning of processing and declined significantly toward the end, while in postproduction, prevalence rose toward the end of processing. Prevalence was higher in the deboning facilities than in slicing facilities and was dependent on the type of surface (floor/drainage > clothing > equipment). The qualitative pattern of contamination was investigated through an analysis of the survey isolates and a set of isolates derived from routine monitoring, including longitudinal isolations. Pulsed-field gel electrophoresis (PFGE) and whole-genome single-nucleotide polymorphism (SNP) analysis revealed a remarkable clonality of L. monocytogenes within plants, with the detection of 16 plant-specific clones out of 17 establishments with multiple isolates. Repeated detections of clonal isolates >6 months apart were also observed. Six was the maximum number of between-isolate differences in core SNPs observed within these clones. Based on the same six-SNP threshold, three clusters of clonal isolates, shared by six establishments, were also identified. The spread of L. monocytogenes within and between plants, as indicated by its clonal behavior, is a matter of concern for the hygienic management of establishments. PMID:26590278

  20. Processes, dynamics and modelling of radiocaesium cycling in a chronosequence of Chernobyl-contaminated Scots pine (Pinus sylvestris L.) plantations.

    PubMed

    Goor, François; Thiry, Yves

    2004-06-01

    of 137Cs level in the wood. The 137Cs contamination of tree components is the result of different influential processes like root uptake, internal translocation and immobilisation. For more accurate predictions, the calibration of existing models would be benefited by comparing with the 137Cs annual fluxes instead of the simple transfer factor coefficients. In the perspective of other applications, there is a need of such data for other radionuclides as well as for heavy metals. PMID:15144787

  1. Critical sources of bacterial contamination and adoption of standard sanitary protocol during semen collection and processing in Semen Station

    PubMed Central

    Sannat, Chandrahas; Nair, Ajit; Sahu, S. B.; Sahasrabudhe, S. A.; Kumar, Ashish; Gupta, Amit Kumar; Shende, R. K.

    2015-01-01

    Aim: The present investigation was conducted to locate the critical sources of bacterial contamination and to evaluate the standard sanitation protocol so as to improve the hygienic conditions during collection, evaluation, and processing of bull semen in the Semen Station. Materials and Methods: The study compared two different hygienic procedures during the collection, evaluation and processing of semen in Central Semen Station, Anjora, Durg. Routinely used materials including artificial vagina (AV) inner liner, cone, semen collection tube, buffer, extender/diluter, straws; and the laboratory environment like processing lab, pass box and laminar air flow (LAF) cabinet of extender preparation lab, processing lab, sealing filling machine, and bacteriological lab were subjected to bacteriological examination in two phases of study using two different sanitary protocols. Bacterial load in above items/environment was measured using standard plate count method and expressed as colony forming unit (CFU). Results: Bacterial load in a laboratory environment and AV equipments during two different sanitary protocol in present investigation differed highly significantly (p<0.001). Potential sources of bacterial contamination during semen collection and processing included laboratory environment like processing lab, pass box, and LAF cabinets; AV equipments, including AV Liner and cone. Bacterial load was reduced highly significantly (p<0.001) in AV liner (from 2.33±0.67 to 0.50±0.52), cone (from 4.16±1.20 to 1.91±0.55), and extender (from 1.33±0.38 to 0) after application of improved practices of packaging, handling, and sterilization in Phase II of study. Glasswares, buffers, and straws showed nil bacterial contamination in both the phases of study. With slight modification in fumigation protocol (formalin @600 ml/1000 ft3), bacterial load was significantly decreased (p<0.001) up to 0-6 CFU in processing lab (from 6.43±1.34 to 2.86±0.59), pass box (from 12.13±2

  2. Separate process wastewaters, part A: Contaminated flow collection and treatment system for the Kansas City Plant

    SciTech Connect

    Not Available

    1995-01-01

    The U.S. Department of Energy (DOE) has prepared this Environmental Assessment (EA) to assist the agency in complying with the National Environmental Policy Act (NEPA) of 1969 as it applies to modification of ongoing groundwater treatment at DOE`s Kansas City Plant (KCP), located about 19 km (12 miles) south of the central business district of Kansas City, Missouri. The KCP is currently owned by DOE and is operated by the Kansas City Division of AlliedSignal Inc. The plant manufactures nonnuclear components for nuclear weapons. The purpose of and need for the DOE action is to treat identified toxic organic contaminated groundwater at the KCP to ensure that human health and the environment are protected and to comply with groundwater treatment requirements of the U.S. Environmental Protection Agency (EPA) Resource Conservation and Recovery Act (RCRA) 3008(h) Administrative Order on Consent and the discharge requirements of the Kansas City, Missouri, ordinances for the city sewer system. Four source streams of toxic organic contaminated groundwater have been identified that require treatment prior to discharge to the city sewer system. The toxic organic contaminants of concern consist of volatile organic compounds (VOCS) in the groundwater and polychlorinated biphenyls (PCBS) predominantly associated with some soils near the Main Manufacturing Building. The no-action alternative is to continue with the current combination of treatment and nontreatment and to continue operation of the KCP groundwater treatment system in its current configuration at Building 97 (B97). The DOE proposed action is to collect and treat all identified toxic organic contaminated groundwater prior to discharge to the city sewer system. The proposed action includes constructing an Organics Collection System and Organics Treatment Building, moving and expanding the existing groundwater treatment system, and operating the new groundwater treatment facility.

  3. Evaluation of the assimilation of As by vegetables in contaminated soils submitted to a remediation process

    NASA Astrophysics Data System (ADS)

    Pérez-Sirvent, Carmen; Martinez Sanchez, Maria Jose; Agudo, Ines; Belen Martinez, Lucia; Bech, Jaume

    2016-04-01

    A greenhouse trial was carried out to evaluate the assimilation of heavy metals by three types of plants (lettuce, onion and broccoli), different parts of which are destined for human and farm animals consumption (leaves, roots, fruits). The experiments were carried out to check the validity of the use of calcareous materials to recover soils contaminated with heavy metals. The aim of this work was to apply a technology for decontamination to ensure that As do not enter into the trophic chain at risky levels and analyze and to assess the risk pre and post operational of the different treatments proposed. The materials used was a soils to be remediated (mining soils) and the materials used for remediation were lime filler and Construction and Demolition Waste (CDW). The plants were cultivated in greenhouse with several types of soil. Five experiments were used, namely, Tc (contaminated soil), T1 (uncontaminated soil (blank soil)), T2 (50% T1 + 50% Tc), T3 (Tc + (25%) lime residues coming from quarries) and T4 (Tc + (25%) residues coming from demolition and construction activities). The entire project involves twenty experiments which were prepared from soils highly contaminated mixed with two types of calcareous materials. The total As content of the soils samples, rhizosphere and vegetable samples, were measured and the translocation factor (TF), which is defined as the ratio of metal concentration in the leaves or shoots to the roots, and the Bioconcentration factor (BCF), which is defined as the ratio of metal concentration in the roots to that in soil were calculated. The use of CDR is shown to be a suitable way for remediating soils contaminated by metals. The methodology permits a revalorization of CDW.

  4. Polychlorinated biphenyl contamination of the spider crab (Maja brachydactyla): influence of physiological and ecological processes.

    PubMed

    Bodin, Nathalie; Caisey, Xavier; Abarnou, Alain; Loizeau, Véronique; Latrouite, Daniel; Le Guellec, Anne-Marie; Guillou, Monique

    2007-03-01

    Maja brachydactyla is a decapod crustacean widely distributed along the Northeast Atlantic coasts. The main objective of this work was to establish the influence of ontogenic factors, such as growth, aging, seasonal migrations, and reproduction, on the contamination of this species by polychlorinated biphenyls (PCBs). Two populations were studied: One in the Seine Bay (Eastern English Channel), which is exposed to greatly contaminated discharges from the Seine River, and one in the Iroise Sea (Western Brittany), which is little contaminated by such man-made compounds. At both sampling areas, PCB analysis revealed concentrations in hepatopancreas that were 10- and 50-fold higher than concentrations in gonads and muscle, respectively. Levels of 2,2',4,4',5,5'-hexachlorobiphenyl (CB153) increased with the age of the spider crabs, whereas their seasonal migrations had no direct effect. No significant sex effect was observed with regards to CB153 levels, but adult females exhibited PCB fingerprints different from those of males, probably because of the influence of the reproductive cycle on enzymatic system activity. Finally, spawning gave rise to a higher CB153 decontamination of female body burdens for specimens from the Iroise Sea than for those from the Seine Bay. PMID:17373508

  5. Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

    SciTech Connect

    Vijayan, S.; Wong, Chi Fun; Buckley, L.P.

    1992-12-31

    It is an object of the claimed invention to combine chemical treatment with microfiltration process to treat groundwater, leachate from contaminated soil washing, surface and run-off waters contaminated with toxic metals, radionuclides and trace amounts of organics from variety of sources. The process can also be used to treat effluents from industrial processes such as discharges associated with smelting, mining and refining operations. Influent contaminants amenable to treatment are from a few mg/L to hundreds of mg/L. By selecting appropriate precipitation, ion exchange and adsorption agents and conditions, efficiencies greater than 99.9 percent can be achieved for removal of contaminants. The filtered water for discharge can be targeted with either an order of magnitude greater or lower than contaminant levels for drinking water.

  6. New wash aid T-128 improves efficacy of chlorine against cross contamination by bacterial pathogens in fresh-cut lettuce processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chlorinated water is widely used as the primary anti-microbial intervention during fresh-cut produce processing. Free chlorine in chlorinated water can provide effective reduction of potential contaminations by microbial pathogens, and, more importantly, effectively prevent cross contamination of p...

  7. 3D Geospatial Models for Visualization and Analysis of Groundwater Contamination at a Nuclear Materials Processing Facility

    NASA Astrophysics Data System (ADS)

    Stirewalt, G. L.; Shepherd, J. C.

    2003-12-01

    Analysis of hydrostratigraphy and uranium and nitrate contamination in groundwater at a former nuclear materials processing facility in Oklahoma were undertaken employing 3-dimensional (3D) geospatial modeling software. Models constructed played an important role in the regulatory decision process of the U.S. Nuclear Regulatory Commission (NRC) because they enabled visualization of temporal variations in contaminant concentrations and plume geometry. Three aquifer systems occur at the site, comprised of water-bearing fractured shales separated by indurated sandstone aquitards. The uppermost terrace groundwater system (TGWS) aquifer is composed of terrace and alluvial deposits and a basal shale. The shallow groundwater system (SGWS) aquifer is made up of three shale units and two sandstones. It is separated from the overlying TGWS and underlying deep groundwater system (DGWS) aquifer by sandstone aquitards. Spills of nitric acid solutions containing uranium and radioactive decay products around the main processing building (MPB), leakage from storage ponds west of the MPB, and leaching of radioactive materials from discarded equipment and waste containers contaminated both the TGWS and SGWS aquifers during facility operation between 1970 and 1993. Constructing 3D geospatial property models for analysis of groundwater contamination at the site involved use of EarthVision (EV), a 3D geospatial modeling software developed by Dynamic Graphics, Inc. of Alameda, CA. A viable 3D geohydrologic framework model was initially constructed so property data could be spatially located relative to subsurface geohydrologic units. The framework model contained three hydrostratigraphic zones equivalent to the TGWS, SGWS, and DGWS aquifers in which groundwater samples were collected, separated by two sandstone aquitards. Groundwater data collected in the three aquifer systems since 1991 indicated high concentrations of uranium (>10,000 micrograms/liter) and nitrate (> 500 milligrams

  8. Use of Zn isotopes as a probe of anthropogenic contamination and biogeochemical processes in the Seine River, France

    NASA Astrophysics Data System (ADS)

    Chen, J.; Gaillardet, J.; Louvat, P.; Birck, J.

    2009-05-01

    Metal contamination is a major issue of human impact on the aqueous environment. River water is particularly susceptible to contamination for both dissolved and particulate loads, displaying a major challenge in understanding the dominant sources and pathways of metals in polluted drainage basins. Recent improvements in mass spectrometry allow isotopic measurements of "non-traditional" metals (Zn, Cu, Fe, etc.), making their isotopes a new potential device to investigate contamination of metals under dissolved and particulate forms in rivers. We focus here on Zn isotope geochemistry in the largely anthropized Seine River (France). A new protocol of two-column separation of Zn from dilute aqueous solution has been developed and proven to be reproducible and satisfactory for accurate measurement of Zn isotopic ratios in water samples by MC-ICP-MS (2σ = 0.04‰). Preliminary results show a total variation of 0.65‰ for δ66Zn in dissolved phases of the Seine basin, and a light isotope enrichment in anthropogenic sources compared to other water samples. The determined conservative behavior of Zn in river water makes its isotopes an effective probe of anthropogenic contamination. The natural and anthropogenic inputs were clearly identified and calculated based on Zn isotope compositions for dissolved loads. Suspended particular matters (SPM) display different Zn isotope compositions compared to dissolved loads, with a total δ66Zn variation of 0.22‰. Zn concentrations and its isotope compositions in SPM reveal inverse relationships as function of the distance from the headwater and the SPM content for geographical and temporal samples, respectively. The δ66Zn data in SPM are interpreted as reflecting the mixture of natural and anthropogenic particles. The correlation between dissolved and particulate δ66Zn shows that adsorption processes are not the dominant process making Zn enrichment in SPM. We report here for the first time systematic δ66Zn data in waters of

  9. An early approach for the evaluation of repair processes in fish after exposure to sediment contaminated by an oil spill.

    PubMed

    Salamanca, Maria J; Jimenez-Tenorio, Natalia; Reguera, Diana F; Morales-Caselles, Carmen; Delvalls, T Angel

    2008-12-01

    A chronic bioassay was carried out under laboratory conditions using juvenile Solea senegalensis to determine the toxicity of contaminants from an oil spill(Prestige). Also, the repair processes in fish affected by contaminants due to oil exposure were evaluated. Over 30 days individuals were exposed to clean sediment (control) and to sediment contaminated by a mixture of polyaromatic hydrocarbons (PAHs) and other substances. The physicochemical parameters of the tanks (salinity, temperature, pH and dissolved oxygen) were controlled during the exposure period. Clean sediment from the Bay of Cadiz (Spain) was used as negative control and was mixed with fuel oil to prepare the dilution (0.5% w:w dry-weight). After the exposure period, fish were labeled and transferred to "clean tanks" (tanks without sediment) in order to study the recovery and the repair processes in the exposed organisms. A biomarker of exposure (ethoxyresorufin-O-deethylase activity - EROD activity) and a biomarker of effect (histopathology) were analyzed during the exposure and recovery period. After 10, 20 and 30 days of exposure, individuals showed significant induction (P < 0.05) of the EROD activity and also presented diverse histopathological damages. The analysis of both the biomarkers of exposure and effect, after the 5th and 10th day of recovery in the "clean tank", enabled a first evaluation of the repair process of the induced damages due to the fuel oil exposure. After the recovery phase, control individuals showed a more significant decrease (P < 0.05) of the alteration of the measured biomarkers than in the oil-exposed fish. While in the oil-exposed fish the EROD activity showed some recovery, the histopathological damages did hardly improve. According to our results, tissue repair processes probably need longer recovery periods to observe significant improvement of the affected organs. This will be further investigated in the future. PMID:18988095

  10. Comparison of reactive transport model predictions for natural attenuation processes occurring at chlorinated solvent contaminated site

    NASA Astrophysics Data System (ADS)

    Chiu, H. M.; Tsai, C. H.; Lai, K. H.; Chen, J. S.

    2014-12-01

    Prediction of an analytical model and numerical model, namely BIOCLOR and HYDRODEOCHEM, for a test scenario involving the natural attenuations of dissolved solvent at chlorinated contaminated site are compared. Two models make same predictions for PCE, TCE and DCE and considerable different predictions for VC and ETH for the case of all species having identical retardation factors. Significant discrepancies between two models are observed for all species when retardation coefficients are considered to be different for all species. These differences can be attributed to the basic assumption that all the species have the same retardation factors embedded in BIOCHLOR.

  11. Processes affecting soil and groundwater contamination by DNAPL in low-permeability media

    SciTech Connect

    McWhorter, D.B.

    1996-08-01

    This paper is one of a set of focus papers intended to document the current knowledge relevant to the contamination and remediation of soils and ground water by dense, nonaqueous phase liquids (DNAPL). The emphasis is on low permeability media such as fractured clay and till and unconsolidated, stratified formations. Basic concepts pertaining to immiscible-fluid mixtures are described and used to discuss such aspects as DNAPL transport, dissolved-phase transport, and equilibrium mass distributions. Several implications for remediation are presented. 27 refs., 8 figs., 4 tabs.

  12. Multiplicative jump processes and applications to leaching of salt and contaminants in the soil

    NASA Astrophysics Data System (ADS)

    Mau, Yair; Feng, Xue; Porporato, Amilcare

    2014-11-01

    We consider simple systems driven multiplicatively by white shot noise, which appear in the modeling of the dynamics of soil nutrients and contaminants. The dynamics of these systems is analyzed in two ways: solving a hierarchy of linear ordinary differential equations for the moments, which gives a time scale of convergence of the stationary probability density function; and characterizing the crossing properties, such as the mean first-passage time and the mean frequency of level crossing. These results are readily applicable to the study of geophysical systems, such as the problem of accumulation of salt in the root zone, i.e., soil salinization.

  13. Rapid and effective decontamination of chlorophenol-contaminated soil by sorption into commercial polymers: concept demonstration and process modeling.

    PubMed

    Tomei, M Concetta; Mosca Angelucci, Domenica; Ademollo, Nicoletta; Daugulis, Andrew J

    2015-03-01

    Solid phase extraction performed with commercial polymer beads to treat soil contaminated by chlorophenols (4-chlorophenol, 2,4-dichlorophenol and pentachlorophenol) as single compounds and in a mixture has been investigated in this study. Soil-water-polymer partition tests were conducted to determine the relative affinities of single compounds in soil-water and polymer-water pairs. Subsequent soil extraction tests were performed with Hytrel 8206, the polymer showing the highest affinity for the tested chlorophenols. Factors that were examined were polymer type, moisture content, and contamination level. Increased moisture content (up to 100%) improved the extraction efficiency for all three compounds. Extraction tests at this upper level of moisture content showed removal efficiencies ≥70% for all the compounds and their ternary mixture, for 24 h of contact time, which is in contrast to the weeks and months, normally required for conventional ex situ remediation processes. A dynamic model characterizing the rate and extent of decontamination was also formulated, calibrated and validated with the experimental data. The proposed model, based on the simplified approach of "lumped parameters" for the mass transfer coefficients, provided very good predictions of the experimental data for the absorptive removal of contaminants from soil at different individual solute levels. Parameters evaluated from calibration by fitting of single compound data, have been successfully applied to predict mixture data, with differences between experimental and predicted data in all cases being ≤3%. PMID:25438115

  14. An investigation of process contaminants' formation during the deep frying of breadcrumbs using a bread coat model.

    PubMed

    Mesías, M; Holgado, F; Márquez-Ruiz, G; Morales, F J

    2016-03-01

    The formation of acrylamide, hydroxymethylfurfural (HMF) and furfural was investigated in a deep fried breadcrumb coat model resembling the coat batter of breaded foods. The influence of the composition of the breadcrumb and the frying conditions on the formation of these contaminants was evaluated. Six wheat-based flour formulations of breadcrumbs were deep fried in sunflower oil at temperatures between 170-200 °C and for frying times of 1-5 minutes. Results showed significant differences in the levels of contaminants according to the concentration of the potential precursors in the breadcrumbs. HMF was influenced by the sugar content in the breadcrumbs whereas levels of acrylamide were significantly correlated with the ratio between asparagine and reducing sugars. Acrylamide, HMF and furfural were directly related to the frying time and temperature. The composition of the breadcrumb and the compounds formed during frying contributed to the total antioxidant capacity of the fried samples. The bread coat model is a useful tool in the formulation of breaded foods since it allows the evaluation of the contribution of breadcrumbs in the formation of process contaminants after frying. PMID:26938951

  15. Numerical simulation of seasonal heat storage in a contaminated shallow aquifer - Temperature influence on flow, transport and reaction processes

    NASA Astrophysics Data System (ADS)

    Popp, Steffi; Beyer, Christof; Dahmke, Andreas; Bauer, Sebastian

    2015-04-01

    The energy market in Germany currently faces a rapid transition from nuclear power and fossil fuels towards an increased production of energy from renewable resources like wind or solar power. In this context, seasonal heat storage in the shallow subsurface is becoming more and more important, particularly in urban regions with high population densities and thus high energy and heat demand. Besides the effects of increased or decreased groundwater and sediment temperatures on local and large-scale groundwater flow, transport, geochemistry and microbiology, an influence on subsurface contaminations, which may be present in the urban surbsurface, can be expected. Currently, concerns about negative impacts of temperature changes on groundwater quality are the main barrier for the approval of heat storage at or close to contaminated sites. The possible impacts of heat storage on subsurface contamination, however, have not been investigated in detail yet. Therefore, this work investigates the effects of a shallow seasonal heat storage on subsurface groundwater flow, transport and reaction processes in the presence of an organic contamination using numerical scenario simulations. A shallow groundwater aquifer is assumed, which consists of Pleistoscene sandy sediments typical for Northern Germany. The seasonal heat storage in these scenarios is performed through arrays of borehole heat exchangers (BHE), where different setups with 6 and 72 BHE, and temperatures during storage between 2°C and 70°C are analyzed. The developing heat plume in the aquifer interacts with a residual phase of a trichloroethene (TCE) contamination. The plume of dissolved TCE emitted from this source zone is degraded by reductive dechlorination through microbes present in the aquifer, which degrade TCE under anaerobic redox conditions to the degradation products dichloroethene, vinyl chloride and ethene. The temperature dependence of the microbial degradation activity of each degradation step is

  16. Transport and deposition of plutonium-contaminated sediments by fluvial processes, Los Alamos Canyon, New Mexico

    SciTech Connect

    Graf, W.L.

    1996-10-01

    Between 1945 and 1952 the development of nuclear weapons at Los Alamos National Laboratory, New Mexico, resulted in the disposal of plutonium into the alluvium of nearby Acid and (to a lesser degree) DP Canyons. The purpose of this paper is to explore the connection between the disposal sites and the main river, a 20 km link formed by the fluvial system of Acid, Pueblo, DP, and Los Alamos Canyons. Empirical data from 15 yr of annual sediment sampling throughout the canyon system has produced 458 observations of plutonium concentration in fluvial sediments. These data show that, overall, mean plutonium concentrations in fluvial sediment decline from 10,000 fCi/g near the disposal area to 100 fCi/g at the confluence of the canyon system and the Rio Grande. Simulations using a computer model for water, sediment, and plutonium routing in the canyon system show that discharges as large as the 25 yr event would fail to develop enough transport capacity to completely remove the contaminated sediments from Pueblo Canyon. Lesser flows would move some materials to the Rio Grande by remobilization of stored sediments. The simulations also show that the deposits and their contaminants have a predictable geography because they occur where stream power is low, hydraulic resistance is high, and the geologic and/or geomorphic conditions provide enough space for storage. 38 refs., 13 figs., 1 tab.

  17. Processing results of 1800 gallons of mercury and radioactively contaminated mixed waste rinse solution

    SciTech Connect

    Thiesen, B.P.

    1993-05-01

    Mercury-contaminated rinse solution was successfully treated at the Idaho National Engineering Laboratory. This waste was generated during the decontamination of the Heat Transfer Reactor Experiment 3 reactor shield tank. Approximately 6.8 m{sup 3} (1,800 pi) of waste was generated and placed into 33 drums. Each drum contained precipitated sludge material ranging from 2--5 cm in depth, with the average depth of about 6 cm. The pH of each drum varied from 3--11. The bulk liquid waste had a mercury level of 7.0 mg/l, which exceeded the Resource Conservation and Recovery Act limit of 0.2 mg/l. The average liquid bulk radioactivity was about 2.1 pCi/mL while the average sludge contamination was about 13,800 pCi/g. Treatment of the waste required separation of the liquid from the sludge, filtration, pH adjustment, and ion exchange. The resulting solution after treatment had mercury levels at 0.0186 mg/l and radioactivity of 0.282 pCi/ml.

  18. Reactive Distillation and Air Stripping Processes for Water Recycling and Trace Contaminant Control

    NASA Technical Reports Server (NTRS)

    Boul, Peter J.; Lange, Kevin E.; Conger, Bruce; Anderson, Molly

    2009-01-01

    Reactive distillation designs are considered to reduce the presence of volatile organic compounds in the purified water. Reactive distillation integrates a reactor with a distillation column. A review of the literature in this field has revealed a variety of functional reactive columns in industry. Wastewater may be purified by a combination of a reactor and a distiller (e.g., the EWRS or VPCAR concepts) or, in principle, through a design which integrates the reactor with the distiller. A review of the literature in reactive distillation has identified some different designs in such combinations of reactor and distiller. An evaluation of reactive distillation and reactive air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

  19. The effect of domestic laundry processes on fungal contamination of socks.

    PubMed

    Amichai, Boaz; Grunwald, Marcelo H; Davidovici, Batya; Farhi, Renata; Shemer, Avner

    2013-11-01

    Tinea pedis is a common chronic skin disease. The role of contaminated clothes as a possible source of reinfection is not fully understood. This study was conducted to evaluate the efficacy of domestic laundering at different temperatures in the eradication of fungal pathogens from contaminated socks. Samples from 81 socks worn by patients suffering from tinea pedis underwent domestic laundering at either 40 °C or 60 °C. The socks were dried at room temperature; fungal cultures were taken from two samples from, respectively, the toe and heel areas of the socks. Samples from socks washed at 40 °C revealed 29 (36%) positive fungal cultures, of which 14 came from the toe and 15 from the heel areas of socks. Trichophyton rubrum was isolated in four specimens, and Aspergillus spp. were found in 20 (70%) specimens. Samples from the same socks washed at 60 °C revealed five (6%) positive fungal cultures, of which three came from the toe and two from the heel areas of socks. Only Aspergillus spp. were detected. Yeasts were eradicated at 40 °C. Contravening current trends for energy saving and environmental protection, laundering at low temperatures is not effective in eradicating fungal pathogens, which requires high-temperature laundering at 60 °C. PMID:23879806

  20. Validation of cross-contamination control in biological safety cabinet for biotech/pharmaceutical manufacturing process.

    PubMed

    Hu, Shih-Cheng; Shiue, Angus; Tu, Jin-Xin; Liu, Han-Yang; Chiu, Rong-Ben

    2015-12-01

    For class II, type A2 biological safety cabinets (BSC), NSF/ANSI Standard 49 should be conformed in cabinet airflow velocity derivation, particle contamination, and aerodynamic flow properties. However, there exists a potential problem. It has been built that the cabinet air flow stabilize is influenced by the quantity of downflow of air and the height above the cabinet exhaust opening. Three air downflow quantities were compared as an operating apparatus was placed from 20 to 40 cm above the bench of the cabinet. The results show that the BSC air downflow velocity is a function of increased sampling height, displaying that containment is improvingly permitted over product protection as the sampling height decreases. This study investigated the concentration gradient of particles at various heights and downflow air quantity from the bench of the BSC. Experiment results indicate that performance near the bench was better than in the rest of the BSC. In terms of height, the best cleanliness was measured at a height of 10 cm over the bench; it reduced actually with add in height. The empirical curves accommodate, founded on the concentration gradient of particle created was elaborated for evaluating the particle concentration at different heights and downflow air quantity from the source of the bench of the BSC. The particle image velocimetry system applied for BSC airflow research to fix amount of airflow patterns and air distribution measurement and results of measurements show how obstructions can greatly influence the airflow and contaminant transportation in a BSC. PMID:26257118

  1. Assessment and optimization of an ultrasound-assisted washing process using organic solvents for polychlorinated biphenyl-contaminated soil.

    PubMed

    Bezama, Alberto; Flores, Alejandra; Araneda, Alberto; Barra, Ricardo; Pereira, Eduardo; Hernández, Víctor; Moya, Heriberto; Konrad, Odorico; Quiroz, Roberto

    2013-10-01

    The goal of this work was to evaluate a washing process that uses organic solutions for polychlorinated biphenyl (PCB)-contaminated soil, and includes an ultrasound pre-treatment step to reduce operational times and organic solvent losses. In a preliminary trial, the suitability of 10 washing solutions of different polarities were tested, from which three n-hexane-based solutions were selected for further evaluation. A second set of experiments was designed using a three-level Taguchi L27 orthogonal array to model the desorption processes of seven different PCB congeners in terms of the variability of their PCB concentration levels, polarity of the washing solution, sonication time, the ratio washing solution/soil, number of extraction steps and total washing time. Linear models were developed for the desorption processes of all congeners. These models provide a good fit with the results obtained. Moreover, statistically significant outcomes were achieved from the analysis of variance tests carried out. It was determined that sonication time and ratio of washing solution/soil were the most influential process parameters. For this reason they were studied in a third set of experiments, constructed as a full factorial design. The process was eventually optimized, achieving desorption rates of more than 90% for all congeners, thus obtaining concentrations lower than 5 ppb in all cases. The use of an ultrasound-assisted soil washing process for PCB-contaminated soils that uses organic solvents seems therefore to be a viable option, especially with the incorporation of an extra step in the sonication process relating to temperature control, which is intended to prevent the loss of the lighter congeners. PMID:23771880

  2. Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Godfroy, Thomas J.

    2008-01-01

    A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 5 psi, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.5 GPM.

  3. Material Studies Related to the Use of NaK Heat Exchangers Coupled to Stirling Heater Heads

    NASA Technical Reports Server (NTRS)

    Locci, Ivan E.; Bowman, Cheryl L.; Geng, Steven M.; Robbie, Malcolm G.

    2011-01-01

    NASA has been supporting design studies and technology development that could provide power to an outpost on the Moon, Mars, or an asteroid. Technology development efforts have included fabrication and evaluation of components used in a Stirling engine power conversion system. Destructive material evaluation was performed on a NaK shell heat exchanger that was developed by the NASA Glenn Research Center (GRC) and integrated with a commercial 1 kWe Stirling convertor from Sunpower Incorporated. The NaK Stirling test demonstrated Stirling convertor electrical power generation using a pumped liquid metal heat source under thermal conditions that represent the heat exchanger liquid metal loop in a Fission Power Systems (FPS) reactor. The convertors were operated for a total test time of 66 hr at a maximum temperature of 823 K. After the test was completed and NaK removed, the heat exchanger assembly was sectioned to evaluate any material interactions with the flowing liquid metal. Several dissimilar-metal braze joint options, crucial for the heat exchanger transfer path, were also investigated. A comprehensive investigation was completed and lessons learned for future heat exchanger development efforts are discussed.

  4. Flow Components in a NaK Test Loop Designed to Simulate Conditions in a Nuclear Surface Power Reactor

    SciTech Connect

    Polzin, Kurt A.; Godfroy, Thomas J.

    2008-01-21

    A test loop using NaK as the working fluid is presently in use to study material compatibility effects on various components that comprise a possible nuclear reactor design for use on the lunar surface. A DC electromagnetic (EM) pump has been designed and implemented as a means of actively controlling the NaK flow rate through the system and an EM flow sensor is employed to monitor the developed flow rate. These components allow for the matching of the flow rate conditions in test loops with those that would be found in a full-scale surface-power reactor. The design and operating characteristics of the EM pump and flow sensor are presented. In the EM pump, current is applied to a set of electrodes to produce a Lorentz body force in the fluid. A measurement of the induced voltage (back-EMF) in the flow sensor provides the means of monitoring flow rate. Both components are compact, employing high magnetic field strength neodymium magnets thermally coupled to a water-cooled housing. A vacuum gap limits the heat transferred from the high temperature NaK tube to the magnets and a magnetically-permeable material completes the magnetic circuit. The pump is designed to produce a pressure rise of 34.5 kPa, and the flow sensor's predicted output is roughly 20 mV at the loop's nominal flow rate of 0.114 m{sup 3}/hr.

  5. DEVELOPMENT OF A SCALABLE, LOW-COST, ULTRANANOCRYSTALLINE DIAMOND ELECTROCHEMICAL PROCESS FOR THE DESTRUCTION OF CONTAMINANTS OF EMERGING CONCERN (CECS) - PHASE I

    EPA Science Inventory

    This Small Business Innovative Research (SBIR) project will develop and ready for commercialization a scalable, low-cost process for purification of water containing Contaminants of Emerging Concern (CECs) using anodic oxidation with boron-doped ultrananocrystalline diam...

  6. Toxicological Benchmarks for Screening Potential Contaminants of Concern for Effects on Soil and Litter Invertebrates and Heterotrophic Process

    SciTech Connect

    Will, M.E.

    1994-01-01

    This report presents a standard method for deriving benchmarks for the purpose of ''contaminant screening,'' performed by comparing measured ambient concentrations of chemicals. The work was performed under Work Breakdown Structure 1.4.12.2.3.04.07.02 (Activity Data Sheet 8304). In addition, this report presents sets of data concerning the effects of chemicals in soil on invertebrates and soil microbial processes, benchmarks for chemicals potentially associated with United States Department of Energy sites, and literature describing the experiments from which data were drawn for benchmark derivation.

  7. Lack of correlation between organic acid concentrations and predominant electron-accepting processes in a contaminated aquifer

    USGS Publications Warehouse

    Vroblesky, D.A.; Bradley, P.M.; Chapelle, F.H.

    1997-01-01

    Long-term (1992-1995) monitoring data from a petroleum hydrocarbon- contaminated aquifer were used to examine the hypothesis that concentrations of low molecular weight (LMW) aliphatic organic acids reflect terminal electron-accepting processes. During the period of study, concentrations of dissolved hydrogen (H2) indicated that methanogenic, sulfate-reducing, and iron(III)-reducing conditions predominated at the site. However, there was no correlation between LMW organic acid concentrations and concentrations of dissolved H2. These results indicate that organic acid concentrations are not a reliable indicator of local redox conditions at this site.

  8. Novel reactor design configuration for contamination control and improved performance in the polysilicon doping process using POCl3

    NASA Astrophysics Data System (ADS)

    Roy, Sudipto R.; Glynn, Phil; Hogan, Rod; Reynolds, Jeff

    1994-08-01

    Conventional POCl3 reactors have process limitations because of the hazardous nature of process by-products. Experiments were conducted using a novel design quartz flange and stainless steel clamp exhaust configuration, along with a scavenger insulation block, which eliminated process by-product buildup inside the reactor tube in the scavenger area. Experiments included variations in doping temperature, process time, POCl3 flow rate, and carrier and exhaust gas flow rates. This novel(sup e) hardware design practically eliminates by-product condensation and dripping outside the reactor, which reduces cross-contamination and stainless steel corrosion problems and prevents potential minority carrier lifetime degradation. Equipment downtime is significantly reduced by eliminating autodoping and the need for frequent process tube steam cleans. Run capability is extended because of the new design, which also provides superior exhaust control and safer operation. The design also allows doubling of the number of wafers processed with improved sheet resistance uniformity. Regression equations were obtained for calculating sheet resistance, which can be a viable tool for process engineers. The new reactor configuration provides significant advantages in reduced equipment downtime, increased savings in material, and improved process performance.

  9. Copper removal from contaminated soils by soil washing process using camellian-derived saponin

    NASA Astrophysics Data System (ADS)

    Reyes, Arturo; Fernanda Campos, Maria; Videla, Álvaro; Letelier, María Victoria; Fuentes, Bárbara

    2015-04-01

    Antofagasta Region in North of Chile has been the main copper producer district in the world. As a consequence of a lack of mining closure regulation, a large number of abandon small-to-medium size metal-contaminated sites have been identified in the last survey performed by the Chilean Government. Therefore, more research development on sustainable reclamation technologies must be made in this extreme arid-dry zone. The objective of this study is to test the effectiveness of soil remediation by washing contaminated soil using camellian-derived saponin for the mobilization of copper. Soil samples were taken from an abandoned copper mine site located at 30 km North Antofagasta city. They were dried and sieved at 75 µm for physico-chemical characterization. A commercial saponin extracted from camellias seed was used as biosurfactant. The soil used contains 67.4 % sand, 26.3 % silt and 6.3 % clay. The soil is highly saline (electric conductivity, 61 mScm-1), with low organic matter content (0.41%), with pH 7.30, and a high copper concentration (2200 mg Kg-1 soil). According to the sequential extraction procedure of the whole soil, copper species are mainly as exchangeable fraction (608.2 mg Kg-1 soil) and reducible fraction (787.3 mg Kg-1 soil), whereas the oxidizable and residual fractions are around 205.7 and 598.8 mg Kg-1 soil, respectively. Soil particles under 75 µm contain higher copper concentrations (1242 mg Kg-1 soil) than the particle fraction over 75 µm (912 mg Kg-1 soil). All washing assays were conducted in triplicate using a standard batch technique with and without pH adjustment. The testing protocols includes evaluation of four solid to liquid ratio (0.5:50; 1.0:50; 2.0:50, and 5.0:50) and three saponin concentrations (0, 1, and 4 mg L-1). After shaking (24 h, 20±1 °C) and subsequently filtration (0.45 µm), the supernatants were analyzed for copper and pH. The removal efficiencies of copper by saponin solutions were calculated in according to the

  10. First on-sun test of NaK pool-boiler solar receiver

    NASA Astrophysics Data System (ADS)

    Moreno, J. B.; Andraka, C. E.; Moss, T. A.; Cordeiro, P. G.; Dudley, V. E.; Rawlinson, K. S.

    During 1989-1990, a refluxing liquid-metal pool-boiler solar receiver designed for dish/Stirling application at 75 kW(sub t) throughput was successfully demonstrated at Sandia National Laboratories. Significant features of this receiver included (1) boiling sodium as the heat transfer medium, and (2) electric-discharge-machined (EDM) cavities as artificial nucleation sites to stabilize boiling. Following this first demonstration, a second-generation pool-boiler receiver that brings the concept closer to commercialization has been designed, constructed, and successfully tested. For long life, the new receiver is built from Haynes Alloy 230. For increased safety factors against film boiling and flooding, the absorber area and vapor-flow passages have been enlarged. To eliminate the need for trace heating, sodium has been replaced by the sodium-potassium alloy NaK-78. To reduce manufacturing costs, the receiver has a powdered-metal coating instead of EDM cavities for stabilization of boiling. To control incipient-boiling superheats, especially during hot restarts, it contains a small amount of xenon. In this paper, we present the receiver design and report the results of on-sun tests using a nominal 75 kW(sub t) test-bed concentrator to characterize boiling stability, hot-restart behavior, and thermal efficiency at temperatures up to 750 C. We also report briefly on late results from an advanced-concepts pool-boiler receiver.

  11. First on-sun test of NaK-78 pool-boiler solar receiver

    SciTech Connect

    Moreno, J.B.; Andraka, C.E.; Moss, T.A.; Cordeiro, P.G.; Dudley, V.E.; Rawlinson, K.S.

    1993-01-01

    During 1989--1990, a refluxing liquid-metal pool-boiler solar receiver designed for dish/Stirling application at 75 kW[sub t] throughput was successfully demonstrated at Sandia National Laboratories. Significant features of this receiver included (1) boiling sodium as the heat transfer medium and (2) electric-discharge-machined (EDM) cavities as artificial nucleation sites to stabilize boiling. Following this first demonstration, a second-generation pool-boiler receiver that brings the concept closer to commercialization has been designed, constructed, and successfully tested. For long life, the new receiver is built from Haynes Alloy 230. For increased safety factors against film boiling and flooding, the absorber area and vapor-flow passages have been enlarged. To eliminate the need for trace heating, sodium has been replaced by the sodium-potassium alloy NaK-78. To reduce manufacturing costs, the receiver has a powdered-metal coating instead of EDM cavities for stabilization of boiling. To control incipient-boiling superheats, especially during hot it contains a small amount of xenon. In this paper, we present the receiver design and report the results of on-sun tests using a nominal 75 kW[sub t] test-bed concentrator to characterize boiling stability, hot-restart behavior, and thermal efficiency at temperatures up to 750[degrees]C. We also report briefly on late results from an advanced-concepts pool-boiler receiver.

  12. First on-sun test of NaK-78 pool-boiler solar receiver

    SciTech Connect

    Moreno, J.B.; Andraka, C.E.; Moss, T.A.; Cordeiro, P.G.; Dudley, V.E.; Rawlinson, K.S.

    1993-06-01

    During 1989--1990, a refluxing liquid-metal pool-boiler solar receiver designed for dish/Stirling application at 75 kW{sub t} throughput was successfully demonstrated at Sandia National Laboratories. Significant features of this receiver included (1) boiling sodium as the heat transfer medium and (2) electric-discharge-machined (EDM) cavities as artificial nucleation sites to stabilize boiling. Following this first demonstration, a second-generation pool-boiler receiver that brings the concept closer to commercialization has been designed, constructed, and successfully tested. For long life, the new receiver is built from Haynes Alloy 230. For increased safety factors against film boiling and flooding, the absorber area and vapor-flow passages have been enlarged. To eliminate the need for trace heating, sodium has been replaced by the sodium-potassium alloy NaK-78. To reduce manufacturing costs, the receiver has a powdered-metal coating instead of EDM cavities for stabilization of boiling. To control incipient-boiling superheats, especially during hot it contains a small amount of xenon. In this paper, we present the receiver design and report the results of on-sun tests using a nominal 75 kW{sub t} test-bed concentrator to characterize boiling stability, hot-restart behavior, and thermal efficiency at temperatures up to 750{degrees}C. We also report briefly on late results from an advanced-concepts pool-boiler receiver.

  13. Osmoregulation requires brain expression of the renal Na-K-2Cl cotransporter NKCC2.

    PubMed

    Konopacka, Agnieszka; Qiu, Jing; Yao, Song T; Greenwood, Michael P; Greenwood, Mingkwan; Lancaster, Thomas; Inoue, Wataru; Mecawi, Andre de Souza; Vechiato, Fernanda M V; de Lima, Juliana B M; Coletti, Ricardo; Hoe, See Ziau; Martin, Andrew; Lee, Justina; Joseph, Marina; Hindmarch, Charles; Paton, Julian; Antunes-Rodrigues, Jose; Bains, Jaideep; Murphy, David

    2015-04-01

    The Na-K-2Cl cotransporter 2 (NKCC2) was thought to be kidney specific. Here we show expression in the brain hypothalamo-neurohypophyseal system (HNS), wherein upregulation follows osmotic stress. The HNS controls osmotic stability through the synthesis and release of the neuropeptide hormone, arginine vasopressin (AVP). AVP travels through the bloodstream to the kidney, where it promotes water conservation. Knockdown of HNS NKCC2 elicited profound effects on fluid balance following ingestion of a high-salt solution-rats produced significantly more urine, concomitant with increases in fluid intake and plasma osmolality. Since NKCC2 is the molecular target of the loop diuretics bumetanide and furosemide, we asked about their effects on HNS function following disturbed water balance. Dehydration-evoked GABA-mediated excitation of AVP neurons was reversed by bumetanide, and furosemide blocked AVP release, both in vivo and in hypothalamic explants. Thus, NKCC2-dependent brain mechanisms that regulate osmotic stability are disrupted by loop diuretics in rats. PMID:25834041

  14. Rotationally inelastic collisions of He and Ar with NaK: Theory and Experiment

    NASA Astrophysics Data System (ADS)

    Price, T. J.; Towne, A. C.; Richter, K.; Jones, J.; Hickman, A. P.; Huennekens, J.; Faust, C.; Malenda, R. F.; Ross, A. J.; Crozet, P.; Talbi, D.; Forrey, R. C.

    2016-05-01

    Rotationally inelastic thermal collisions of NaK A1Σ+ molecules with He and Ar have been studied at Lehigh and Lyon. In both laboratories, a pump laser excites a particular ro-vibrational level A1Σ+ (v , J). Strong transitions from the pumped (v , J) level and weaker transitions from collisionally-populated levels (v ,J' = J + ΔJ) occur. Ratios of line intensities yield information about population and orientation transfer. At Lyon, we also identify v changing collisions. A strong propensity for ΔJ = even transitions is observed for He and Ar. Theoretical calculations are underway; we've calculated He-NaK and Ar-NaK potential surfaces using GAMESS and performed coupled channel scattering calculations for JM -->J'M' transitions. Semiclassical formulas for the cross sections have been obtained and agree well with our quantum mechanical calculations. Using the vector model, where J precesses with polar angle θ about the z-axis, we derived the distribution of final polar angles θ' and final M' states. We identify a special case where the θ' distribution is a Lorentzian centered at θ. Work supported by NSF, XSEDE and CNRS (PICS).

  15. Structure determination in 55-atom Li-Na and Na-K nanoalloys.

    PubMed

    Aguado, Andrés; López, José M

    2010-09-01

    The structure of 55-atom Li-Na and Na-K nanoalloys is determined through combined empirical potential (EP) and density functional theory (DFT) calculations. The potential energy surface generated by the EP model is extensively sampled by using the basin hopping technique, and a wide diversity of structural motifs is reoptimized at the DFT level. A composition comparison technique is applied at the DFT level in order to make a final refinement of the global minimum structures. For dilute concentrations of one of the alkali atoms, the structure of the pure metal cluster, namely, a perfect Mackay icosahedron, remains stable, with the minority component atoms entering the host cluster as substitutional impurities. At intermediate concentrations, the nanoalloys adopt instead a core-shell polyicosahedral (p-Ih) packing, where the element with smaller atomic size and larger cohesive energy segregates to the cluster core. The p-Ih structures show a marked prolate deformation, in agreement with the predictions of jelliumlike models. The electronic preference for a prolate cluster shape, which is frustrated in the 55-atom pure clusters due to the icosahedral geometrical shell closing, is therefore realized only in the 55-atom nanoalloys. An analysis of the electronic densities of states suggests that photoelectron spectroscopy would be a sufficiently sensitive technique to assess the structures of nanoalloys with fixed size and varying compositions. PMID:20831313

  16. Osmoregulation Requires Brain Expression of the Renal Na-K-2Cl Cotransporter NKCC2

    PubMed Central

    Konopacka, Agnieszka; Qiu, Jing; Yao, Song T.; Greenwood, Michael P.; Greenwood, Mingkwan; Lancaster, Thomas; Inoue, Wataru; de Souza Mecawi, Andre; Vechiato, Fernanda M.V.; de Lima, Juliana B.M.; Coletti, Ricardo; Hoe, See Ziau; Martin, Andrew; Lee, Justina; Joseph, Marina; Hindmarch, Charles; Paton, Julian; Antunes-Rodrigues, Jose; Bains, Jaideep

    2015-01-01

    The Na-K-2Cl cotransporter 2 (NKCC2) was thought to be kidney specific. Here we show expression in the brain hypothalamo-neurohypophyseal system (HNS), wherein upregulation follows osmotic stress. The HNS controls osmotic stability through the synthesis and release of the neuropeptide hormone, arginine vasopressin (AVP). AVP travels through the bloodstream to the kidney, where it promotes water conservation. Knockdown of HNS NKCC2 elicited profound effects on fluid balance following ingestion of a high-salt solution—rats produced significantly more urine, concomitant with increases in fluid intake and plasma osmolality. Since NKCC2 is the molecular target of the loop diuretics bumetanide and furosemide, we asked about their effects on HNS function following disturbed water balance. Dehydration-evoked GABA-mediated excitation of AVP neurons was reversed by bumetanide, and furosemide blocked AVP release, both in vivo and in hypothalamic explants. Thus, NKCC2-dependent brain mechanisms that regulate osmotic stability are disrupted by loop diuretics in rats. PMID:25834041

  17. Ultrasonic and mechanical soil washing processes for the remediation of heavy-metal-contaminated soil

    NASA Astrophysics Data System (ADS)

    Kim, Seulgi; Lee, Wontae; Son, Younggyu

    2016-07-01

    Ultrasonic/mechanical soil washing process was investigated and compared with ultrasonic process and mechanical process using a relatively large lab-scale sonoreactor. It was found that higher removal efficiencies were observed in the combined processes for 0.1 and 0.3 M HCl washing liquids. It was due to the combination effects of macroscale removal for the overall range of slurry by mechanical mixing and microscale removal for the limited zone of slurry by cavitational actions.

  18. Molecular-level processes governing the interaction of contaminants with iron and manganese oxides. 1997 annual progress report

    SciTech Connect

    Chambers, S.A.; Brown, G.

    1997-06-01

    'The central tenet of this proposal is that a fundamental understanding of specific mineral surface-site reactivities will substantially improve reactive transport models of contaminants in geologic systems, and will allow more effective remediation schemes to be devised. Most large-scale, macroscopic models employ global chemical reaction kinetics and thermochemistry. However, such models do not incorporate molecular-level input critical to the detailed prediction of how contaminants interact with minerals in the subsurface. A first step leading to the incorporation of molecular-level processes in large-scale macroscopic models is the ability to understand which molecular-level processes will dominate the chemistry at the microscopic grain level of minerals. To this end, the research focuses on the fundamental mechanisms of redox chemistry at mineral surfaces. As much of this chemistry in sediments involves the Fe(III)/Fe(II) and Mn(IV)/Mn(II) couples, the authors focus on mineral phases containing these species. Of particular interest is the effect of the local coordination environment of Fe and Mn atoms on their reactivity toward contaminant species. Studies of the impact of local atomic structure on reactivity in combination with knowledge about the types and amounts of various surfaces on natural grain- size minerals provide the data for statistical models. These models in turn form the basis of the larger-scale macroscopic descriptions of reactivity that are needed for reactive transport models. A molecular-level understanding of these mechanisms will enhance the ability to design much greater performance efficiency, cost effectiveness, and remediation strategies that have minimal negative impact on the local environment. For instance, a comprehensive understanding of how minerals that contain Fe(II) reduce oxyanions and chlorinated organics should enable the design of other Fe(II)-containing remediation materials in a way that is synergistic with existing

  19. Radioactive contamination processes during 14-21 March after the Fukushima accident: What does atmospheric electric field measurements tell us?

    NASA Astrophysics Data System (ADS)

    Takeda, M.; Yamauchi, M.; Makino, M.; Owada, T.; Miyagi, I.

    2012-04-01

    Ionizing radiation from the radioactive material is known to increase atmospheric electric conductivity, and hence to decrease vertical downward atmospheric DC electric field at ground level, or potential gradient (PG). In the past, the drop of PG has been observed after rain-induced radioactive fallout (wet contamination) after nuclear tests or after the Chernobyl disaster. After the nuclear accident Fukushima Dai-ichi nuclear power plant (FNPP) that started 11 March 2011, the PG also at Kakioka, 150 km southwest from the FNPP, also dropped a by one order of magnitude. Unlike the past examples, the PG drop was two-stepped on 14 March and 20 March. Both correspond to two largest southward release of radioactive material according to the data from the radiation dose rate measurement network. We compare the Kakioka's PG data with the radiation dose rate data at different places to examine the fallout processes of both on 14 March and on 20 March. The former turned out to be dry contamination by surface wind, leaving a substantial amount of fallout floating near the ground. The latter turned out to be wet contamination by rain after transport by relatively low-altitude wind, and the majority of the fallout settled to the ground at this time. It is recommended that all nuclear power plant to have a network of PG observation surrounding the plant. Takeda, et al. (2011): Initial effect of the Fukushima accident on atmospheric electricity, Geophys. Res. Lett., 38, L15811, doi:10.1029/2011GL048511. Yamauchi, et al. (2012): Settlement process of radioactive dust to the ground inferred from the atmospheric electric field measurement, Ann. Geophys., 30, 49-56, doi:10.5194/angeo-30-49-2012.

  20. Bacterial diversity of floor drain biofilms and drain waters in a Listeria monocytogenes contaminated food processing environment.

    PubMed

    Dzieciol, Monika; Schornsteiner, Elisa; Muhterem-Uyar, Meryem; Stessl, Beatrix; Wagner, Martin; Schmitz-Esser, Stephan

    2016-04-16

    Sanitation protocols are applied on a daily basis in food processing facilities to prevent the risk of cross-contamination with spoilage organisms. Floor drain water serves along with product-associated samples (slicer dust, brine or cheese smear) as an important hygiene indicator in monitoring Listeria monocytogenes in food processing facilities. Microbial communities of floor drains are representative for each processing area and are influenced to a large degree by food residues, liquid effluents and washing water. The microbial communities of drain water are steadily changing, whereas drain biofilms provide more stable niches. Bacterial communities of four floor drains were characterized using 16S rRNA gene pyrosequencing to better understand the composition and exchange of drain water and drain biofilm communities. Furthermore, the L. monocytogenes contamination status of each floor drain was determined by applying cultivation-independent real-time PCR quantification and cultivation-dependent detection according to ISO11290-1. Pyrosequencing of 16S rRNA genes of drain water and drain biofilm bacterial communities yielded 50,611 reads, which were clustered into 641 operational taxonomic units (OTUs), affiliated to 16 phyla dominated by Proteobacteria, Firmicutes and Bacteroidetes. The most abundant OTUs represented either product- (Lactococcus lactis) or fermentation- and food spoilage-associated phylotypes (Pseudomonas mucidolens, Pseudomonas fragi, Leuconostoc citreum, and Acetobacter tropicalis). The microbial communities in DW and DB samples were distinct in each sample type and throughout the whole processing plant, indicating the presence of indigenous specific microbial communities in each processing compartment. The microbiota of drain biofilms was largely different from the microbiota of the drain water. A sampling approach based on drain water alone may thus only provide reliable information on planktonic bacterial cells but might not allow conclusions

  1. Simulating long term nitrate-N contamination processes in the Woodville Karst Plain using CFPv2 with UMT3D

    NASA Astrophysics Data System (ADS)

    Xu, Zexuan; Hu, Bill X.; Davis, Hal; Cao, Jianhua

    2015-05-01

    A research version of CFP (Conduit Flow Process) code, CFPv2, is applied with UMT3D to simulate long term (1966-2018) nitrate-N contamination transport processes in the Woodville Karst Plain (WKP), northern Florida, where karst conduit networks are well developed. Groundwater flow in the WKP limestone porous matrix is simulated using Darcy's law, and non-laminar flow within conduits is described by Darcy-Weisbach equation. Nitrate-N conduit transport and advective exchanges of groundwater and nitrate-N between conduits and limestone matrix are calculated by CFPv2 and UMT3D, instead of MODFLOW and MT3DMS since Reynolds numbers for flows in conduits are over the criteria of laminar flow. The developed numerical model is calibrated by field observations and then applied to simulate nitrate-N transport in the WKP. The numerical simulations verify the theories that two sprayfields near the City of Tallahassee and septic tanks in the rural area are major nitrate-N point sources within the WKP. High nitrate-N concentrations occur near Lost Creek Sink, and conduits of Wakulla Spring and Spring Creek Springs where aquifer discharge groundwater. Conduit networks control nitrate-N transport and regional contaminant distributions in the WKP, as nitrate-N is transported through conduits rapidly and spread over large areas.

  2. Combination of surfactant enhanced soil washing and electro-Fenton process for the treatment of soils contaminated by petroleum hydrocarbons.

    PubMed

    Huguenot, David; Mousset, Emmanuel; van Hullebusch, Eric D; Oturan, Mehmet A

    2015-04-15

    In order to improve the efficiency of soil washing treatment of hydrocarbon contaminated soils, an innovative combination of this soil treatment technique with an electrochemical advanced oxidation process (i.e. electro-Fenton (EF)) has been proposed. An ex situ soil column washing experiment was performed on a genuinely diesel-contaminated soil. The washing solution was enriched with surfactant Tween 80 at different concentrations, higher than the critical micellar concentration (CMC). The impact of soil washing was evaluated on the hydrocarbons concentration in the leachates collected at the bottom of the soil columns. These eluates were then studied for their degradation potential by EF treatment. Results showed that a concentration of 5% of Tween 80 was required to enhance hydrocarbons extraction from the soil. Even with this Tween 80 concentration, the efficiency of the treatment remained very low (only 1% after 24 h of washing). Electrochemical treatments performed thereafter with EF on the collected eluates revealed that the quasi-complete mineralization (>99.5%) of the hydrocarbons was achieved within 32 h according to a linear kinetic trend. Toxicity was higher than in the initial solution and reached 95% of inhibition of Vibrio fischeri bacteria measured by Microtox method, demonstrating the presence of remaining toxic compounds even after the complete degradation. Finally, the biodegradability (BOD₅/COD ratio) reached a maximum of 20% after 20 h of EF treatment, which is not enough to implement a combined treatment with a biological treatment process. PMID:25646675

  3. Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

    DOEpatents

    Vijayan, Sivaraman; Wong, Chi F.; Buckley, Leo P.

    1994-01-01

    In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved.

  4. Waste treatment process for removal of contaminants from aqueous, mixed-waste solutions using sequential chemical treatment and crossflow microfiltration, followed by dewatering

    DOEpatents

    Vijayan, S.; Wong, C.F.; Buckley, L.P.

    1994-11-22

    In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it meets a specified target water quality, or else the filtrate is recycled until the target is achieved. 1 fig.

  5. Phosphorylation of rat kidney Na-K pump at Ser938 is required for rapid angiotensin II-dependent stimulation of activity and trafficking in proximal tubule cells.

    PubMed

    Massey, Katherine J; Li, Quanwen; Rossi, Noreen F; Keezer, Susan M; Mattingly, Raymond R; Yingst, Douglas R

    2016-02-01

    How angiotensin (ANG) II acutely stimulates the Na-K pump in proximal tubules is only partially understood, limiting insight into how ANG II increases blood pressure. First, we tested whether ANG II increases the number of pumps in plasma membranes of native rat proximal tubules under conditions of rapid activation. We found that exposure to 100 pM ANG II for 2 min, which was previously shown to increase affinity of the Na-K pump for Na and stimulate activity threefold, increased the amount of the Na-K pump in plasma membranes of native tubules by 33%. Second, we tested whether previously observed increases in phosphorylation of the Na-K pump at Ser(938) were part of the stimulatory mechanism. These experiments were carried out in opossum kidney cells, cultured proximal tubules stably coexpressing the ANG type 1 (AT1) receptor, and either wild-type or a S938A mutant of rat kidney Na-K pump under conditions found by others to stimulate activity. We found that 10 min of incubation in 10 pM ANG II stimulated activity of wild-type pumps from 2.3 to 3.5 nmol K · mg protein(-1) · min(-1) and increased the amount of the pump in the plasma membrane by 80% but had no effect on cells expressing the S938A mutant. We conclude that acute stimulation of Na-K pump activity in native rat proximal tubules includes increased trafficking to the plasma membrane and that phosphorylation at Ser(938) is part of the mechanism by which ANG II directly stimulates activity and trafficking of the rat kidney Na-K pump in opossum kidney cells. PMID:26582472

  6. Remediation of nitrate-contaminated water by Fe{sup 0}-promoted processes

    SciTech Connect

    Zawaideh, L.L.; Chew, C.F.; Zhang, T.C.

    1997-12-31

    The feasibility of using zero-valent iron powder to remediate nitrate-contaminated water was studied using bench-scale batch and fixed-bed column reactors. Operational parameters, such as Fe{sup 0} dosage (w/v), initial concentration of nitrate-nitrogen, pH, and the use of an organic buffer (HEPES), were studied to determine the effectiveness of nitrate removal using zero-valent iron powder. Nitrate-nitrogen was removed by 94% when 0.01 M of HEPES was added to a non-shaking batch reactor containing 20 mg/l nitrate-nitrogen and 4% (w/v) of Fe{sup 0}. Shaking was proved to be more efficient than no shaking. Using the response surface methodology it was found that nitrate removal was closely related to pH. At low pH, the nitrate removal was fast and efficient; at high pH the transformation of nitrate was fast and efficient only at low nitrate concentrations in the Fe{sup 0}-H{sub 2}O system; at normal pH range nitrate removal was usually lower than 50% without buffer treatment. The addition of the organic buffer (HEPES) greatly enhanced the nitrate transformation in a wide pH range. Preliminary column experiments verified the batch experimental results on pH and buffer effects.

  7. Trace organic contaminants in biosolids: Impact of conventional wastewater and sludge processing technologies and emerging alternatives.

    PubMed

    Semblante, Galilee U; Hai, Faisal I; Huang, Xia; Ball, Andrew S; Price, William E; Nghiem, Long D

    2015-12-30

    This paper critically reviews the fate of trace organic contaminants (TrOCs) in biosolids, with emphasis on identifying operation conditions that impact the accumulation of TrOCs in sludge during conventional wastewater and sludge treatment and assessing the technologies available for TrOC removal from biosolids. The fate of TrOCs during sludge thickening, stabilisation (e.g. aerobic digestion, anaerobic digestion, alkaline stabilisation, and composting), conditioning, and dewatering is elucidated. Operation pH, sludge retention time (SRT), and temperature have significant impact on the sorption and biodegradation of TrOCs in activated sludge that ends up in the sludge treatment line. Anaerobic digestion may exacerbate the estrogenicity of sludge due to bioconversion to more potent metabolites. Application of advanced oxidation or thermal pre-treatment may minimise TrOCs in biosolids by increasing the bioavailability of TrOCs, converting TrOCs into more biodegradable products, or inducing complete mineralisation of TrOCs. Treatment of sludge by bioaugmentation using various bacteria, yeast, or fungus has the potential to reduce TrOC levels in biosolids. PMID:26151380

  8. Hydrochemical processes controlling arsenic and heavy metal contamination in the Elqui river system (Chile).

    PubMed

    Dittmar, Thorsten

    2004-06-01

    Severe arsenic poisoning from drinking water has been documented in Northern Chile. However, the Elqui River, which provides water for approximately 200,000 people in this region, is poorly studied and no data on contaminants have been published to date. In this study, trace elements and the main aqueous constituents were monitored for approximately 2 years in the entire river system. Aqueous species of trace elements were determined via thermodynamic equilibrium calculations, and two operationally-defined suspended fractions were analyzed. Chalco- and arsenopyrite deposits in the upper Andes, in conjunction with mining and geothermal activity, were identified as exclusive point sources of heavy metals and arsenic. The annual input to the river system was approximately (t year(-1)): Fe 600, Mn 110, Cu 130, Zn 35 and As 2.0. The confluence with pH-buffered waters in the upper river system caused collapse of iron hydroxide colloids and coprecipitation of all heavy metals, e.g. dissolved copper concentrations decreased from approximately 100 to approximately 0.2 micromol l(-1), which is still of ecotoxic concern. The heavy metal enriched suspended solids settled only in the lower Elqui River. Arsenate did not adsorb to suspended solids and behaved strictly conservatively, exceeding the WHO guideline value for drinking water (0.13 micromol l(-1)) in the entire river system. Decontamination may be accomplished with reasonable efforts upstream in direct vicinity to the sources via coprecipitation, settling and appropriate pH adjustment for arsenate adsorption. PMID:15144789

  9. High pressure processing and its application to the challenge of virus-contaminated foods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High pressure processing (HPP) is an increasingly popular non-thermal food processing technology. Study of HPP’s potential to inactivate foodborne viruses has defined general pressure levels required to inactivate hepatitis A virus, norovirus surrogates, and human norovirus itself within foods such...

  10. Assessment of Microbial Contaminants Present on Vacuum Loaders in Shell Egg Processing Facilities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have shown vacuum loader cups in shell egg processing facilities to be a reservoir of high levels of bacteria. This study was conducted to determine the prevalence of pathogens on the surface of the vacuum loaders cups. An off-line and a mixed operation shell egg processing facili...

  11. 9 CFR 310.25 - Contamination with microorganisms; process control verification criteria and testing; pathogen...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...; process control verification criteria and testing; pathogen reduction standards. 310.25 Section 310.25... criteria and testing; pathogen reduction standards. (a) Criteria for verifying process control; E. coli... complied with and written notice of same has been provided to the establishment. (b) Pathogen...

  12. 9 CFR 310.25 - Contamination with microorganisms; process control verification criteria and testing; pathogen...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...; process control verification criteria and testing; pathogen reduction standards. 310.25 Section 310.25... criteria and testing; pathogen reduction standards. (a) Criteria for verifying process control; E. coli... complied with and written notice of same has been provided to the establishment. (b) Pathogen...

  13. EFFECT OF BACTERIAL LOAD ON CHICKENS ENTERING THE PROCESSING PLANT ON FINAL CARCASS CONTAMINATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Regulatory and poultry industry efforts to control Salmonella in the United States have focus primarily on the processing plant. Industry and research studies have strongly suggested that the level of Salmonella entering the processing plant will impact the ability of in-plant interventions to redu...

  14. Remediation of nitrate-contaminated water by solid-phase denitrification process-a review.

    PubMed

    Ashok, Vaishali; Hait, Subrata

    2015-06-01

    The paper presents a compilation of various autotrophic and heterotrophic ways of solid-phase denitrification. It covers a complete understanding of various pathways followed during denitrification process. The paper gives a brief review on various governing factors on which the process depends. It focuses mainly on the solid-phase denitrification process, its applicability, efficiency, and disadvantages associated. It presents a critical review on various methodologies associated with denitrification process reported in past years. A comparative study has also been carried out to have a better understanding of advantages and disadvantages of a particular method. We summarize the various organic and inorganic substances and various techniques that have been used for enhancing denitrification process and suggest possible gaps in the research areas whi'ch are worthy of future research. PMID:25787220

  15. Pilot-scale ISCO treatment of a MtBE contaminated site using a Fenton-like process.

    PubMed

    Innocenti, Ivan; Verginelli, Iason; Massetti, Felicia; Piscitelli, Daniela; Gavasci, Renato; Baciocchi, Renato

    2014-07-01

    This paper reports about a pilot-scale feasibility study of In-Situ Chemical Oxidation (ISCO) application based on the use of stabilized hydrogen peroxide catalyzed by naturally occurring iron minerals (Fenton-like process) to a site formerly used for fuel storage and contaminated by MtBE. The stratigraphy of the site consists of a 2-3 meter backfill layer followed by a 3-4 meter low permeability layer, that confines the main aquifer, affected by a widespread MtBE groundwater contamination with concentrations up to 4000 μg/L, also with the presence of petroleum hydrocarbons. The design of the pilot-scale treatment was based on the integration of the results obtained from experimental and numerical modeling accounting for the technological and regulatory constraints existing in the site to be remediated. In particular, lab-scale batch tests allowed the selection of the most suitable operating conditions. Then, this information was implemented in a numerical software that allowed to define the injection and monitoring layout and to predict the propagation of hydrogen peroxide in groundwater. The pilot-scale field results confirmed the effective propagation of hydrogen peroxide in nearly all the target area (around 75 m(2) using 3 injection wells). As far as the MtBE removal is concerned, the ISCO application allowed us to meet the clean-up goals in an area of 60 m(2). Besides, the concentration of TBA, i.e. a potential by-product of MtBE oxidation, was actually reduced after the ISCO treatment. The results of the pilot-scale test suggest that ISCO may be a suitable option for the remediation of the groundwater plume contaminated by MtBE, providing the background data for the design and cost-estimate of the full-scale treatment. PMID:24518270

  16. Analysis of organic matter at the soil-water interface by NMR spectroscopy: Implications for contaminant sorption processes

    NASA Astrophysics Data System (ADS)

    Simpson, M.; Simpson, A.

    2009-05-01

    Contaminant sorption to soil organic matter (OM) is the main fate of nonionic, hydrophobic organic contaminants in terrestrial environments and a number of studies have suggested that both soil OM structure and physical conformation (as regulated by the clay mineral phase) govern contaminant sorption processes. To investigate this further, a number of soil samples were characterized by both solid-state 13 C Cross Polarization Magic Angle Spinning (CPMAS) NMR and 1H High Resolution Magic Angle Spinning (HR- MAS) NMR. HR-MAS NMR is an innovative NMR method that allows one to examine samples that are semi- solid using liquid state NMR methods (ie: observe 1H which is more sensitive than 13C). With HR-MAS NMR, only those structures that are in contact with the solvent are NMR visible thus one can probe different components within a mixture using different solvents. The 1H HR-MAS NMR spectrum of a grassland soil swollen in water (D2O) is dominated by signals from alkyl and O-alkyl structures but signals from aromatic protons are negligible (the peak at ~8.2ppm is attributed to formic acid). When the soil is swollen in DMSO-d6, a solvent which is more penetrating and capable of breaking hydrogen bonds, aromatic signals are visible suggesting that the aromatic structures are buried within the soil matrix and do not exist at the soil-water interface. The 13C solid-state NMR data confirms that aromatic carbon is present in substantial amounts (estimated at ~40% of the total 13C signal) therefore, the lack of 1H aromatic signals in the HR-MAS NMR spectrum indicates that aromatic structures are buried and that the soil-water interface is dominated by aliphatic chains, carbohydrates, and peptides. The NMR data indicates that the mineral component of soils governs the physical conformation of OM at the soil-water interface.

  17. Contamination control

    SciTech Connect

    Jackson, L.C.

    1983-11-01

    An evaluation showed that fluoropolymer plastic squeeze bottles can replace polyethylene bottles when used for in-process cleaning. Fluoropolymer plastic squeeze bottles do not contaminate solvents stored in the bottles as polyethylene bottles do. In addition, a limited survey of industrial practices regarding aerosol spray container control showed containers are being controlled without inconveniencing production.

  18. Forced gradient infiltration experiments: effect on the release processes of mobile particles and organic contaminants

    NASA Astrophysics Data System (ADS)

    Pagels, B.; Reichel, K.; Totsche, K. U.

    2009-04-01

    Mobile colloidal and suspended matter is likely to affect themobility of polycyclic aromatic hydrocarbons (PAHs) in the unsaturatedsoil zone at contaminated sites. We studied the release of mobile (organic) particles (MOPs), which include among others dissolved and colloidal organic matter in response to forced sprinkling infiltration and multiple flow interrupts using undisturbed zero-tensionlysimeters. The aim was to assess the effect of these MOPs on the exportof PAHs and other contaminants in floodplain soils. Seepage water samples were analyzed for dissolvedand colloidal organic carbon (DOC), PAH, suspended particles, pH, electrical conductivity, turbidity,zeta potential and surface tension in the fraction smaller 0.7 m. In additional selected PAH were analysed in the size fraction > 0.7 m. Bromide was used as a conservative tracer to determine the flow regime. First arrival of bromide was detected 3.8 hours after start of irrigation. The concentration gradually increased and reached a level of C/C0=0.1 just before the flow interrupt (FI). After flow was resumed, effluent bromide concentration was equal to the concentration before the FI. Ongoing irrigation caused a breakthrough wave, which continuously increased until the bromide concentration reached ~100% of the input concentration. A high-intensity rain event of 4 L m -2 h-1 upon summer-dried lysimeters results in a release of particles in a the size of 250-400 nm. In addition it seems that with the initial exported seepage water surface-active agents are released which is indicated by the decrease of the surface to 60 mN m-1 (Pure water: 72mN m-1). The turbidity values range from 8-14 FAU. The concentration of DOC is about 30-40 mg L-1 in the initial effluent fractions and equilibrates to 15 mg L-1 with ongoing percolation. The PAHs in the fraction < 0.7 m amount to 0.02 g L-1, and 0.05 g L-1 in the fraction > 0.7 m. After establishing steady state flow conditions, first arrival of bromide was detected

  19. MICROBIAL PROCESSES AFFECTING MONITORED NATURAL ATTENUATION OF CONTAMINANTS IN THE SUBSURFACE

    EPA Science Inventory

    Natural attenuation, also know as natural assimilation, intrinsic remediation, and passive remediation, along with other appellations, is defined according to the processes of biotic and abiotic transformations while stressing that bioremediation is the major cause for contaminan...

  20. A study of enhanced performance of VUV/UV process for the degradation of micropollutants from contaminated water.

    PubMed

    Bagheri, Mehdi; Mohseni, Madjid

    2015-08-30

    VUV/UV is a chemical-free and straightforward solution for the degradation of emerging contaminants from water sources. The objective of this work was to investigate the feasibility of VUV/UV advanced oxidation process for the effective degradation of a target micropollutant, atrazine, under continuous flow operation of 0.5-6.5L/min. To provide an in-depth understanding of process, a comprehensive computational fluid dynamics (CFD) model, incorporating flow hydrodynamics, 185nm VUV and 254nm UV radiation propagation along with a complete kinetic scheme, was developed and validated experimentally. The experimental degradation rates and CFD predicted values showed great consistency with less than 2.9% average absolute relative deviation (AARD). Utilizing the verified model, energy-efficiency of the VUV/UV process under a wide range of reactor configurations was assessed in terms of electrical energy-per-order (EEO), OH concentration as well as delivered UV and VUV dose distributions. Thereby, the extent of mixing and circulation zones was found as key parameter controlling the treatment economy and energy-efficiency of the VUV/UV process. Utilizing a CFD-driven baffle design strategy, an improved VUV/UV process with up to 72% reduction in the total electrical energy requirement of atrazine degradation was introduced and verified experimentally. PMID:25827391

  1. [Contamination mechanism and regeneration strategies of chromatographic resin in separation process for expression product from mammary gland bioreactor].

    PubMed

    Sun, Xiyan; Zhang, Yan; Li, Yan; Luo, Jian; Qin, Peiyong; Su, Zhiguo

    2011-11-01

    This study focused on the contamination mechanism and regeneration strategies of sulfopropyl ion exchange resin (SP Sepharose FF) during the separation of recombinant human lactoferrin from transgenic bovine milk. We analyzed primary constituents' contents in chromatorgraphic material and fractions. The results showed that the lipid in milk can clog the column or adhere to the resin through hydrophobic interaction, leading to an increase in column pressure. Some casein molecules were found to adsorb onto the resin through electrostatic interaction, therefore the adsorption capacity was decreased. There was no direct interaction between lactose and the resin in the chromatorgraphic process. Increased continuous chromatographic cycles and prolonged time interval between protein purification and column regeneration could enhance the undesirable interaction between the contaminants and resin, thus lowering the regeneration efficiency. NaOH was found to be effective in the removal of lipid and casein molecules from the column. Furthermore, normal microstructure and chromatographic performance of the ion exchanger was recovered after this cleaning procedure. PMID:22393720

  2. Potential accumulation of contaminated sediments in a reservoir of a high-Andean watershed: Morphodynamic connections with geochemical processes

    NASA Astrophysics Data System (ADS)

    Contreras, María. Teresa; Müllendorff, Daniel; Pastén, Pablo; Pizarro, Gonzalo E.; Paola, Chris; Escauriaza, Cristián.

    2015-05-01

    Rapid changes due to anthropic interventions in high-altitude environments, such as the Altiplano region in South America, require new approaches to understand the connections between physical and geochemical processes. Alterations of the water quality linked to the river morphology can affect the ecosystems and human development in the long term. The future construction of a reservoir in the Lluta River, located in northern Chile, will change the spatial distribution of arsenic-rich sediments, which can have significant effects on the lower parts of the watershed. In this investigation, we develop a coupled numerical model to predict and evaluate the interactions between morphodynamic changes in the Lluta reservoir, and conditions that can potentially desorb arsenic from the sediments. Assuming that contaminants are mobilized under anaerobic conditions, we calculate the oxygen concentration within the sediments to study the interactions of the delta progradation with the potential arsenic release. This work provides a framework for future studies aimed to analyze the complex connections between morphodynamics and water quality, when contaminant-rich sediments accumulate in a reservoir. The tool can also help to design effective risk management and remediation strategies in these extreme environments. This article was corrected on 15 JUNE 2015. See the end of the full text for details.

  3. Groundwater contamination in coastal urban areas: Anthropogenic pressure and natural attenuation processes. Example of Recife (PE State, NE Brazil)

    NASA Astrophysics Data System (ADS)

    Bertrand, G.; Hirata, R.; Pauwels, H.; Cary, L.; Petelet-Giraud, E.; Chatton, E.; Aquilina, L.; Labasque, T.; Martins, V.; Montenegro, S.; Batista, J.; Aurouet, A.; Santos, J.; Bertolo, R.; Picot, G.; Franzen, M.; Hochreutener, R.; Braibant, G.

    2016-09-01

    In a context of increasing land use pressure (over-exploitation, surface-water contamination) and repeated droughts, identifying the processes affecting groundwater quality in coastal megacities of the tropical and arid countries will condition their long-term social and environmental sustainability. The present study focuses on the Brazilian Recife Metropolitan Region (RMR), which is a highly urbanized area (3,743,854 inhabitants in 2010) on the Atlantic coast located next to an estuarial zone and overlying a multi-layered sedimentary system featured by a variable sediment texture and organic content. It investigates the contamination and redox status patterns conditioning potential attenuation within the shallow aquifers that constitute the interface between the city and the strategic deeper semi-confined aquifers. These latter are increasingly exploited, leading to high drawdown in potenciometric levels of 20-30 m and up to 70 m in some high well density places, and potentially connected to the surface through leakage. From a multi-tracer approach (major ions, major gases, δ11B, δ18O-SO4, δ34S-SO4) carried out during two field campaigns in September 2012 and March 2013 (sampling of 19 wells and 3 surface waters), it has been possible to assess the contamination sources and the redox processes. The increasing trend for mineralization from inland to coastal and estuarial wells (from 119 to around 10,000 μS/cm) is at first attributed to water-rock interactions combined with natural and human-induced potentiometric gradients. Secondly, along with this trend, one finds an environmental pressure gradient related to sewage and/or surface-channel network impacts (typically depleted δ11B within the range of 10-15‰) that are purveyors of chloride, nitrate, ammonium and sulfate. Nitrate, ammonium and sulfate (ranging from 0 to 1.70 mmol/L, from 0 to 0,65 mmol/L, from 0.03 to 3.91 mmol/L respectively are also potentially produced or consumed through various redox

  4. Groundwater contamination in coastal urban areas: Anthropogenic pressure and natural attenuation processes. Example of Recife (PE State, NE Brazil).

    PubMed

    Bertrand, G; Hirata, R; Pauwels, H; Cary, L; Petelet-Giraud, E; Chatton, E; Aquilina, L; Labasque, T; Martins, V; Montenegro, S; Batista, J; Aurouet, A; Santos, J; Bertolo, R; Picot, G; Franzen, M; Hochreutener, R; Braibant, G

    2016-09-01

    In a context of increasing land use pressure (over-exploitation, surface-water contamination) and repeated droughts, identifying the processes affecting groundwater quality in coastal megacities of the tropical and arid countries will condition their long-term social and environmental sustainability. The present study focuses on the Brazilian Recife Metropolitan Region (RMR), which is a highly urbanized area (3,743,854 inhabitants in 2010) on the Atlantic coast located next to an estuarial zone and overlying a multi-layered sedimentary system featured by a variable sediment texture and organic content. It investigates the contamination and redox status patterns conditioning potential attenuation within the shallow aquifers that constitute the interface between the city and the strategic deeper semi-confined aquifers. These latter are increasingly exploited, leading to high drawdown in potenciometric levels of 20-30m and up to 70m in some high well density places, and potentially connected to the surface through leakage. From a multi-tracer approach (major ions, major gases, δ(11)B, δ(18)O-SO4, δ(34)S-SO4) carried out during two field campaigns in September 2012 and March 2013 (sampling of 19 wells and 3 surface waters), it has been possible to assess the contamination sources and the redox processes. The increasing trend for mineralization from inland to coastal and estuarial wells (from 119 to around 10,000μS/cm) is at first attributed to water-rock interactions combined with natural and human-induced potentiometric gradients. Secondly, along with this trend, one finds an environmental pressure gradient related to sewage and/or surface-channel network impacts (typically depleted δ(11)B within the range of 10-15‰) that are purveyors of chloride, nitrate, ammonium and sulfate. Nitrate, ammonium and sulfate (ranging from 0 to 1.70mmol/L, from 0 to 0,65mmol/L, from 0.03 to 3.91mmol/L respectively are also potentially produced or consumed through various redox

  5. Receptor-assay for endogenous inhibitors of Na-K ATPase.

    PubMed

    Favre, H; Siegenthaler, G; Martin, B; Roth, D; Granges, G; Louis, F

    1987-01-01

    It is now accepted that there is an endogenous digitalis-like substance (EDLS), previously called natriuretic factor, present in different mammalian species which participates to the regulation of the sodium balance and at least in some situations, to the genesis of hypertension. The physiological and pathophysiological role of this substance is well recognized. However, its chemical nature remains elusive. Our purpose was to define a receptor assay for this EDLS in order to be able to measure its concentration in urine and blood. To do so, we first prepared a pool of lyophylised urine from salt loaded men. The active material was isolated by Sephadex G25 chromatography. Using the same active fraction, we investigated its biological effects. Series of experiments have demonstrated the various properties of the EDLS: inducing natriuresis when injected into a rat, diminishing short circuit current in toad's bladder and colonic mucosa of rat in in vitro preparations, inhibiting Na-K ATPase activity in isolated toad's bladder cells, binding to ouabain receptors and cross-reacting with different antibodies directed against digoxin. Among these properties, the binding to ouabain receptors offers the unique opportunity to progress in our knowledges of the substance, making possible the calculation of its constant of affinity and the estimation of the molality of the active material contained in a gram of crude extract. Knowing the constant of affinity of the EDLS for its receptor would provide the best identification of the substance as long as we do not know its exact chemical nature.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3599802

  6. Biogeochemical cycles of Chernobyl-born radionuclides in the contaminated forest ecosystems: long-term dynamics of the migration processes

    NASA Astrophysics Data System (ADS)

    Shcheglov, Alexey; Tsvetnova, Ol'ga; Klyashtorin, Alexey

    2013-04-01

    Biogeochemical migration is a dominant factor of the radionuclide transport through the biosphere. In the early XX century, V.I. Vernadskii, a Russian scientist known, noted about a special role living things play in transport and accumulation of natural radionuclide in various environments. The role of biogeochemical processes in migration and redistribution of technogenic radionuclides is not less important. In Russia, V. M. Klechkovskii and N.V. Timofeev-Ressovskii showed some important biogeochemical aspects of radionuclide migration by the example of global fallout and Kyshtym accident. Their followers, R.M. Alexakhin, M.A. Naryshkin, N.V. Kulikov, F.A. Tikhomirov, E.B. Tyuryukanova, and others also contributed a lot to biogeochemistry of radionuclides. In the post-Chernobyl period, this area of knowledge received a lot of data that allowed building the radioactive element balance and flux estimation in various biogeochemical cycles [Shcheglov et al., 1999]. Regrettably, many of recent radioecological studies are only focused on specific radionuclide fluxes or pursue some applied tasks, missing the holistic approach. Most of the studies consider biogeochemical fluxes of radioactive isotopes in terms of either dose estimation or radionuclide migration rates in various food chains. However, to get a comprehensive picture and develop a reliable forecast of environmental, ecological, and social consequences of radioactive pollution in a vast contaminated area, it is necessary to investigate all the radionuclide fluxes associated with the biogeochemical cycles in affected ecosystems. We believe such an integrated approach would be useful to study long-term environmental consequences of the Fukushima accident as well. In our long-term research, we tried to characterize the flux dynamics of the Chernobyl-born radionuclides in the contaminated forest ecosystems and landscapes as a part of the integrated biogeochemical process. Our field studies were started in June of

  7. Combined column and cell flotation process for the treatment of PAH contaminated hazardous wastes produced by an aluminium production plant.

    PubMed

    Dhenain, Aurélie; Mercier, Guy; Blais, Jean-François; Chartier, Myriam

    2009-06-15

    The aluminium electrolytic plants generate PAH and fluoride contaminated wastes which are usually classified as hazardous material. These residues are generally disposed in secure landfill sites. A flotation cell process was previously developed to remove PAH from these aluminium industry wastes. The tests were done on composite samples made of particle size fractions under 50mm. The efficiency of the flotation cell process was demonstrated but the high quantity of concentrate produced (14.0%) during the air injection period, because of the solid entrainment, raised the treatment cost. The aim of this study was to reduce the entrainment of fine particles in order to obtain an efficient and economic technology. The process initially developed was modified: the smallest particle size fraction (<0.5mm) of the composite sample was treated in a flotation column, whereas the other particle size fractions (0.5-50mm) were treated in a flotation cell. The separated treatment allowed to reduce the entrainment during the air injection period of the flotation cell step from 14.0% to 10.1%. The optimum total solids of the pulp and cocamidopropylhydroxysultaine (CAS) concentration were 3.33% and 0.50% (ww(-1)) for the flotation column, and 15% and 0.25% (ww(-1)) for the flotation cell. This combined flotation process minimized the total entrainment which allowed a 23.6% abatement of the concentrate quantity initially produced, and reduced the PAH concentrations of the wastes under the authorized limit of 1000 mg kg(-1). PMID:19013712

  8. Prevalence and Contamination Patterns of Listeria monocytogenes in Fresh Catfish Fillets and their Processing Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Catfish skins, intestines, fresh fillets, processing surfaces at different production stages, chiller water and non-food contact surfaces were sampled for Listeria monocytogenes and other Listeria species. Among 315 samples, prevalence of L. monocytogenes, Listeria innocua and a group of Listeria se...

  9. Investigation of metal contamination induced by a through silicon via reveal process using direct Si/Cu grinding and residual metal removal

    NASA Astrophysics Data System (ADS)

    Watanabe, Naoya; Aoyagi, Masahiro; Katagawa, Daisuke; Bandoh, Tsubasa; Mitsui, Takahiko; Yamamoto, Eiichi

    2016-06-01

    We investigated metal contamination induced by a through silicon via (TSV) reveal process using direct Si/Cu grinding and residual metal removal. A complementary metal oxide semiconductor (CMOS) wafer including TSVs was bonded to a glass support substrate, and a TSV reveal process was performed by direct Si/Cu grinding and residual metal removal. Then, metal contamination near the SiO2/Si interface on the front side of the wafer was investigated by using a pulsed-MOS capacitor technique and measuring the effective generation lifetime and effective surface generation velocity before and after this TSV reveal process. The results of Zerbst analysis showed that the changes in average effective generation lifetime and average effective surface generation velocity were ‑5.4 and +4.2%, respectively. These results demonstrate that the effect of metal contamination induced by our TSV reveal process on circuit components is small.

  10. TiO2 and Fe (III) photocatalytic ozonation processes of a mixture of emergent contaminants of water.

    PubMed

    Rodríguez, Eva M; Fernández, Guadalupe; Alvarez, Pedro M; Beltrán, Fernando J

    2012-01-01

    A mixture of three emergent contaminants: testosterone (TST), bisphenol A (BPA) and acetaminophen (AAP) has been treated with different photocatalytic oxidation systems. Homogeneous catalysts as Fe(III) alone or complexed with oxalate or citrate ions, heterogeneous catalysts as titania, and oxidants such as hydrogen peroxide and/or ozone have been used to constitute the oxidation systems. For the radiation type, black light lamps mainly emitting at 365 nm have been used. The effects of pH (3 and 6.5) have been investigated due to the importance of this variable both in ozone and Fe(III) systems. Removal of initial compounds and mineralization (total organic carbon: TOC) were followed among other parameters. For the initial compounds removal ozonation alone, in many cases, allows the highest elimination rates, regardless of the presence or absence of UVA light and catalyst. For mineralization, however, ozone photocatalytic processes clearly leads to the highest oxidation rates. PMID:22078252

  11. FTY720P inhibits hepatic Na(+)-K(+) ATPase via S1PR2 and PGE2.

    PubMed

    Al Alam, Nadine; Kreydiyyeh, Sawsan Ibrahim

    2016-08-01

    Sphingosine-1-phosphate (S1P) was found previously to inhibit Na(+)-K(+) ATPase in HepG2 cells. Whether fingolimod (FTY720), a S1P receptor (S1PR) agonist, similarly inhibits the ATPase is a question that needs to be addressed. The aim of this work was to study the effect of FTY720P, the active form of the drug, on the activity of Na(+)-K(+) ATPase in HepG2 cells and determine its mechanism of action. The activity of the ATPase was assayed by measuring the amount of inorganic phosphate liberated in the presence and the absence of ouabain. FTY720-P (7.5 nmol/L, 15 min) significantly reduced the activity of the ATPase. This effect disappeared completely in the presence of JTE-013, which is a specific blocker of sphingosine-1-phosphate receptor 2 (S1PR2), as well as in the presence of calphostin and indomethacin, which are inhibitors of protein kinase C (PKC) and COX-2, respectively. The effect of FTY720P was mimicked by prostaglandin E2 (PGE2) and PMA, but abrogated by NF-κB inhibition. When NF-κB was inhibited, the effect of exogenous PGE2 still appeared, but that of PMA did not manifest, suggesting that NF-κB is upstream of PGE2 and downstream of PKC. It was concluded that FTY720P activates via S1PR2, PKC, and NF-κB. The latter induces PGE2 generation and inhibits Na(+)-K(+) ATPase. PMID:27501354

  12. Removal of contaminant gases from an electrolytic urine pretreatment process. [in spacecraft life support systems

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.; Putnam, D. F.

    1977-01-01

    The effluent gas stream from an electrolytic urine pretreatment process was analyzed by gas chromatography-mass spectroscopy and wet chemical methods to determine its composition. The major constituents were identified as: hydrogen, carbon dioxide, oxygen, nitrogen, water vapor, and chlorine. The trace impurities were chlorinated light hydrocarbons, and a number of other organic impurities in the low ppm range. Several methods of removing all of the undesirable gases to levels acceptable for return to a space cabin atmosphere were investigated experimentally. A subsystem concept comprised of the following sequential unit processes and operations was successfully demonstrated: (1) raw urine scrubbing, (2) silica gel sorption, (3) dilution with cabin air, and (4) catalytic oxidation.

  13. Landfill mining from a deposit of the chlorine/organochlorine industry as source of dioxin contamination of animal feed and assessment of the responsible processes.

    PubMed

    Torres, João Paulo Machado; Leite, Claudio; Krauss, Thomas; Weber, Roland

    2013-04-01

    In 1997, the Polychlorinated dibenzo-para-dioxin (PCDD)/Polychlorinated dibenzofuran (PCDF) concentrations in dairy products in Germany and other European countries increased. The PCDD/PCDF source was contaminated lime used in Brazilian citrus pulp pellets. The contaminated lime was mined from an industrial dump site. However, the detailed origin of the PCDD/PCDFs in the lime was not revealed. This paper investigates the contamination origin and describes the link between lime milk from the dumpsite of a chlorine/organochlorine industry and the contaminated lime. The contaminated lime stem from mining at the corporate landfill of Solvay Indupa in Sao Paulo. The landfill was used for 40 years for deposition of production residues and closed in 1996. The factory operated/operates at least two processes with potentially high PCDD/PCDFs releases namely the oxychlorination process for production of ethylene dichloride (EDC) and the chlor-alkali process. The main landfilled waste was lime milk (1.4 million tons) from the vinyl chloride monomer production (via the acetylene process) along with residues from other processes. The PCDD/PCDF fingerprint revealed that most samples from the chemical landfill showed an EDC PCDD/PCDF pattern with a characteristic octachlorodibenzofuran dominance. The PCDD/PCDF pattern of a Rio Grande sediment samples downstream the facility showed a chlor-alkali pattern with a minor impact of the EDC pattern. The case highlights that PCDD/PCDF- and persistent organic pollutants-contaminated sites need to be identified in a comprehensive manner as required by the Stockholm Convention (article 6) and controlled for their impact on the environment and human health. Landfill mining and reuse of materials from contaminated deposits should be prohibited. PMID:22828923

  14. ORGANIC-CONTAMINANT DESTRUCTION UNIT ECO LOGIC PROCESS GAS PHASE CHEMICAL REDUCTION

    SciTech Connect

    Unknown

    1998-06-17

    This report describes the Eco Logic Process and discusses the procedures and results of a pilot-scale treatability study on explosives in shell casings. The study was conducted as part of a contract which was awarded to Science Applications International Corporation (SAIC) and Eco Logic by the Department of Energy's Federal Energy Technology Center (FETC) in Morgantown, West Virginia to conduct treatability studies on complex hazardous wastes, energetic and low level mixed wastes. The U.S. Army currently decontaminates spent shell casings using a bailout or high pressure wash process that removes a large amount of the propellant from the casing but not enough to allow recycle of the entire casing intact; the U.S. Army currently projects the use of a metal parts furnace to completely decontaminate the shell casings. Use of the Eco Logic Process to decontaminate the shell casings would allow the shell casing to be reused intact. In addition to explosives commonly used by the Army such as TNT and Composition B, ARDEC personnel also were interested in the decontamination of shell casings with a residual of the propellant Yellow D which is a common energetic in artillery shell casings used by the Navy. A series of treatability tests on neat samples of explosive as well as shell casings containing each explosive were performed between June 9 and June 20, 1997 at the US Army's Edgewood Research Development, Engineering Center (ERDEC) toxic test chamber facility located at Aberdeen Proving Ground, Maryland., including a 2 gram neat sample of TNT and lO gram samples of TNT, composition B and Yellow D to determine optimal treatment conditions for each explosive followed by two tests on washed shell casings containing trace amounts of TNT and a total of six tests, two each on shell casings lined with 10 grams of TNT, composition B and Yellow D.

  15. Initial field test of High-Energy Corona process for treating a contaminated soil-offgas stream

    SciTech Connect

    Shah, R R; Garcia, R E; Jeffs, J T; Virden, J W; Heath, W O

    1995-04-01

    The High-Energy Corona (HEC) technology for treating process offgases has been under development at Pacific Northwest Laboratory (PNL) since 1991. The HEC process uses high-voltage electrical discharges in air to ionize the air, forming a low-temperature plasma that would be expected to destroy a wide variety of organic compounds in air. The plasma contains strong oxidants, possibly including hydroxyl radicals, hydroperoxy radicals, superoxide radicals, various excited as well as ionized forms of oxygen, high-energy electrons, and ultraviolet (UV) light. Because the high-voltage plasma is produced near ambient temperatures and pressures, yet exhibits extremely rapid destruction kinetics with relatively low power requirements, the HEC technique appears promising as a low-cost treatment technique (Virden et al. 1992). As part of the Volatile Organic Compound (VOC) Nonarid Integrated Demonstration (ID) at the DOE Savannah River Site, research activities were initiated in December 1991 to develop a prototype HEC process for a small-scale field demonstration to treat a soil-offgas stream contaminated with trichloroethylene (TCE) and perchloroethylene (PCE) at varying concentrations. Over an 18-month period, the HEC technology was developed on a fast track, through bench and pilot scales into a trailer-mounted system that was tested at the Nonarid ID. Other national laboratories, universities, and private companies have also participated at the Nonarid ID to demonstrate a number of conventional, emerging and innovative approaches for treating the same soil-offgas stream.

  16. Effect of halide ions and carbonates on organic contaminant degradation by hydroxyl radical-based advanced oxidation processes in saline waters.

    PubMed

    Grebel, Janel E; Pignatello, Joseph J; Mitch, William A

    2010-09-01

    Advanced oxidation processes (AOPs) generating nonselective hydroxyl radicals (HO*) provide a broad-spectrum contaminant destruction option for the decontamination of waters. Halide ions are scavengers of HO* during AOP treatment, such that treatment of saline waters would be anticipated to be ineffective. However, HO* scavenging by halides converts HO* to radical reactive halogen species (RHS) that participate in contaminant destruction but react more selectively with electron-rich organic compounds. The effects of Cl-, Br-, and carbonates (H2CO3+HCO3-+CO3(2-)) on the UV/H2O2 treatment of model compounds in saline waters were evaluated. For single target organic contaminants, the impact of these constituents on contaminant destruction rate suppression at circumneutral pH followed the order Br->carbonates>Cl-. Traces of Br- in the NaCl stock had a greater effect than Cl- itself. Kinetic modeling of phenol destruction demonstrated that RHS contributed significantly to phenol destruction, mitigating the impact of HO* scavenging. The extent of treatment efficiency reduction in the presence of halides varied dramatically among different target organic compounds. Destruction of contaminants containing electron-poor reaction centers in seawater was nearly halted, while 17beta-estradiol removal declined by only 3%. Treatment of mixtures of contaminants with each other and with natural organic matter (NOM) was evaluated. Although NOM served as an oxidant scavenger, conversion of nonselective HO* to selective radicals due to the presence of anions enhanced the efficiency of electron-rich contaminant removal in saline waters by focusing the oxidizing power of the system away from the NOM toward the target contaminant. Despite the importance of contaminant oxidation by halogen radicals, the formation of halogenated byproducts was minimal. PMID:20681567

  17. Decomposition of gaseous organic contaminants by surface discharge induced plasma chemical processing -- SPCP

    SciTech Connect

    Oda, Tetsuji; Yamashita, Ryuichi; Haga, Ichiro; Takahashi, Tadashi; Masuda, Senichi

    1996-01-01

    The decomposition performance of the surface induced plasma chemical processing (SPCP) for chlorofluorocarbon (83 ppm CFC-113 in air), acetone, trichloroethylene, and isopropylalcohol was experimentally examined. In every case, very high decomposition performance, more than 90 or 99% removal rate, is realized when the residence time is about 1 second and the input electric power for a 16 cm{sup 3} reactor is about 10 W. Acetone is the most stable compound and alcohol is most easily decomposed. The decomposed product-analysis by a GasChromato-MassSpectrometer has just started but very poor results are obtained. In fact, some portion of the isopropylalcohol may change to acetone which is worse than alcohol. The necessary energy to decompose one mol gas diluted in the air is calculated form the experiments. The necessary energy level for acetone and trichloroethylene is about one-tenth or one-fiftieth of that for chlorofluorocarbon.

  18. In-situ surface contamination removal and cool-down process of the DEAP-3600 experiment

    NASA Astrophysics Data System (ADS)

    Giampa, Pietro; DEAP Collaboration

    2016-05-01

    The DEAP-3600 experiment is a single-phase detector that uses 3600 Kg of liquid argon to search for Dark Matter at SNOLAB, Sudbury, Canada, 6800 ft. underground. The projected sensitivity to the spin-independent WIMP-nucleon cross-section is 10-46 cm2 for a WIMP mass of 100 GeV. A key experimental requirement is the reduction of any possible source of background that would mimic a Dark Matter signal This document will review how radiogenic surface backgrounds were reduced in-situ by removing 500 microns of acrylic from the innermost part of the detector with a resurfacing robot. Furthermore it will review the transient cool-down process of the experiment, necessary to reach cryogenic operating temperature.

  19. Outbreak of Salmonella Livingstone infection in Norway and Sweden due to contaminated processed fish products.

    PubMed Central

    Guerin, P. J.; De Jong, B.; Heir, E.; Hasseltvedt, V.; Kapperud, G.; Styrmo, K.; Gondrosen, B.; Lassen, J.; Andersson, Y.; Aavitsland, P.

    2004-01-01

    In Europe, the number of reported sporadic human cases of Salmonella Livingstone infection is low, and outbreaks are rare. We report the largest S. Livingstone outbreak described in the literature having an identified source of infection. In February 2001, an increased incidence of infection caused by S. Livingstone was observed in Norway and Sweden. By July 2001, 44 cases were notified in Norway and 16 in Sweden. The median age was 63 years, and 40 were women. There were three deaths, and 22 patients were hospitalized. Based on standardized questionnaires and retrospective studies of S. Livingstone strains in Norway and Sweden, food items with egg powder were suspected, and S. Livingstone was subsequently recovered from a processed fish product at the retail level. Analysis by pulsed-field gel electrophoresis documented that isolates from the fish product belonged to the same clone as the outbreak strain. PMID:15473152

  20. Processes affecting the fate of monoaromatic hydrocarbons in an aquifer contaminated by crude oil

    USGS Publications Warehouse

    Eganhouse, R.P.; Dorsey, T.F.; Phinney, C.S.; Westcott, A.M.

    1996-01-01

    Crude oil spilled from a subsurface pipeline in north-central Minnesota has dissolved in the groundwater, resulting in the formation of a plume of aliphatic, aromatic, and alicyclic hydrocarbons. Comparison of paired oil and groundwater samples collected along the central axis of the residual oil body shows that the trailing edge of the oil is depleted in the more soluble aromatic hydrocarbons (e.g., benzene, toluene, etc.) when compared with the leading edge. At the same time, concentrations of monoaromatic hydrocarbons in groundwater beneath the oil increase as the water moves toward the leading edge of the oil. Immediately downgradient from the leading edge of the oil body, certain aromatic hydrocarbons (e.g., benzene) are found at concentrations near those expected of a system at equilibrium, and the concentrations exhibit little variation over time (???8-20%). Other compounds (e.g., toluene) appear to be undersaturated, and their concentrations show considerably more temporal variation (???20-130%). The former are persistent within the anoxic zone downgradient from the oil, whereas concentrations of the latter decrease rapidly. Together, these observations suggest that the volatile hydrocarbon composition of the anoxic groundwater near the oil body is controlled by a balance between dissolution and removal rates with only the most persistent compounds reaching saturation. Examination of the distributions of homologous series and isomeric assemblages of alkylbenzenes reveals that microbial degradation is the dominant process controlling the fate of these compounds once groundwater moves away from the oil. For all but the most persistent compounds, the distal boundary of the plume at the water table extends no more than 10-15 m down-gradient from the oxic/anoxic transition zone. Thus, transport of the monoaromatic hydrocarbons is limited by redox conditions that are tightly coupled to biological degradation processes.

  1. Remediation of TCE contaminated soils by in situ EK-Fenton process.

    PubMed

    Yang, G C; Liu, C Y

    2001-08-17

    The treatment performance and cost analysis of in situ electrokinetic (EK)-Fenton process for oxidation of trichloroethylene (TCE) in soils were evaluated in this work. In all experiments, an electric gradient of 1V/cm, de-ionized water as the cathode reservoir fluid and a treatment time of 10 days were employed. Treatment efficiencies of TCE were evaluated in terms of the electrode material, soil type, catalyst type, and catalyst dosage and granular size if applicable. Test results show that graphite electrodes are superior to stainless steel electrodes. It was found that the soil with a higher content of organic matter would result in a lower treatment efficiency (e.g. a sandy loam is less efficient than a loamy sand). Experimental results show that the type of catalyst and its dosage would markedly affect the reaction mechanisms (i.e. "destruction" and "removal") and the treatment efficiency. Aside from FeSO4, scrap iron powder (SIP) in the form of a permeable reactive wall was also found to be an effective catalyst for Fenton reaction to oxidize TCE. In general, the smaller the granular size of SIP, the lower the overall treatment efficiency and the greater the destruction efficiency. When a greater quantity of SIP was used, a decrease of the overall treatment efficiency and an increase of percent destruction of TCE were found. Experimental results have shown that the quantity of electro-osmotic (EO) flow decreased as the quantity of SIP increased. It has been verified that the treatment performances are closely related to the corresponding EO permeability. Results of the cost analysis have indicated that the EK-Fenton process employed in this work is very cost-effective with respect to TCE destruction. PMID:11489531

  2. Process and equipment for the utilization of thermal energy of waste having been subjected to oil contamination

    SciTech Connect

    Vajdovich, G.; Csorba, I.

    1984-02-07

    A process and apparatus is discussed for recovering the heat content of oil-contaminated waste water wherein the waste water is collected and is conducted through a plurality of waste water carrying ducts with shut-off valves, from an oil manipulating system into a single duct with a shut-off valve. A duct with two branches is attached to and leads from the shut-off valve. Each branch of the branched duct has a magnet valve which operates contrarily to the magnet valve in the other branch. Each of the magnet valves are connected by means of a cable to an instrument which senses the oil content of the waste water. If the instrument does not sense oil, one magnet valve is open and the other is closed, and if the instrument senses oil, the other magnet valve is open and the one magnet valve is closed. A pressurized sample collector is connected via a duct to one of the magnet valves, and the sensing instrument. A pressurized collector having a sampling place on a float is connected by a duct to a sampling vessel and the sensing instrument. A duct for carrying the waste water from the collector is connected to a shut-off means and a pump which is connected to and controlled by a sensing instrument. This waste water duct transports the uncontaminated waste water through a check valve for further utilization and carries the contaminated waste water through a duct leading from the other magnet valve to an external repository.

  3. Annexin A2 Mediates Apical Trafficking of Renal Na+-K+-2Cl− Cotransporter*

    PubMed Central

    Dathe, Christin; Daigeler, Anna-Lena; Seifert, Wenke; Jankowski, Vera; Mrowka, Ralf; Kalis, Ronny; Wanker, Erich; Mutig, Kerim; Bachmann, Sebastian; Paliege, Alexander

    2014-01-01

    The furosemide-sensitive Na+-K+-2Cl− cotransporter (NKCC2) is responsible for urine concentration and helps maintain systemic salt homeostasis. Its activity depends on trafficking to, and insertion into, the apical membrane, as well as on phosphorylation of conserved N-terminal serine and threonine residues. Vasopressin (AVP) signaling via PKA and other kinases activates NKCC2. Association of NKCC2 with lipid rafts facilitates its AVP-induced apical translocation and activation at the surface. Lipid raft microdomains typically serve as platforms for membrane proteins to facilitate their interactions with other proteins, but little is known about partners that interact with NKCC2. Yeast two-hybrid screening identified an interaction between NKCC2 and the cytosolic protein, annexin A2 (AnxA2). Annexins mediate lipid raft-dependent trafficking of transmembrane proteins, including the AVP-regulated water channel, aquaporin 2. Here, we demonstrate that AnxA2, which binds to phospholipids in a Ca2+-dependent manner and may organize microdomains, is codistributed with NKCC2 to promote its apical translocation in response to AVP stimulation and low chloride hypotonic stress. NKCC2 and AnxA2 interact in a phosphorylation-dependent manner. Phosphomimetic AnxA2 carrying a mutant phosphoacceptor (AnxA2-Y24D-GFP) enhanced surface expression and raft association of NKCC2 by 5-fold upon low chloride hypotonic stimulation, whereas AnxA2-Y24A-GFP and PKC-dependent AnxA2-S26D-GFP did not. As the AnxA2 effect involved only nonphosphorylated NKCC2, it appears to affect NKCC2 trafficking. Overexpression or knockdown experiments further supported the role of AnxA2 in the apical translocation and surface expression of NKCC2. In summary, this study identifies AnxA2 as a lipid raft-associated trafficking factor for NKCC2 and provides mechanistic insight into the regulation of this essential cotransporter. PMID:24526686

  4. Groundwater Ages and Stable Isotope Fingerprints of Contaminated Water to Examine Potential Solute Sources at a Uranium Processing Mill

    NASA Astrophysics Data System (ADS)

    Hurst, T. G.; Solomon, D. K.

    2007-12-01

    To evaluate sources of high solute concentrations in groundwater near a uranium processing facility, groundwater recharge dates are correlated to specific solute concentrations and depth in the water column. Stable isotopes are also used as potential fingerprints of water sourced from mill tailing cells. Passive diffusion samplers, to be analyzed for 3He/4He ratio, were deployed in 15 different wells with samplers at two depths in the saturated interval. Low-flow purging and sampling was then conducted to isolate sampling points at different depths in the wells, with sampling at multiple depths being completed in 4 of the 15 wells sampled. Laboratory analyses were conducted for CFC recharge age, as well as T/3He recharge age. Contract laboratories analyzed for: deuterium and oxygen-18 isotopes of water; sulfur-34 and oxygen-18 isotopes of sulfate; trace metals uranium, manganese, and selenium; and nitrate and sulfate. Analysis for 235U/238U isotope ratios will be conducted to further identify fingerprint signals of source water. Groundwater recharge ages determined using CFC analysis show some vertical stratification in ages across the water column. Upon initial data processing and analysis, measured CFC ages ranged from 30 to 40 years within the water column of one well to only several years difference in another well. Additional results for trace metal concentrations, stable isotope ratios, and T/3He recharge ages will be reported when results are received. Further post-processing of CFC laboratory analysis and noble gas analyses will provide greater clarity as to groundwater ages within the aquifer and, combined with field pumping data, will allow for a comprehensive groundwater model to be constructed. This study provides great insight to potential mine tailings leakage problems and using isotopes and groundwater age dating techniques as a means of tracing contaminated groundwater to the leakage source. Utilizing stable isotopes of water and sulfate, combined

  5. Synergistic Processing of Biphenyl and Benzoate: Carbon Flow Through the Bacterial Community in Polychlorinated-Biphenyl-Contaminated Soil

    PubMed Central

    Leewis, Mary-Cathrine; Uhlik, Ondrej; Leigh, Mary Beth

    2016-01-01

    Aerobic mineralization of PCBs, which are toxic and persistent organic pollutants, involves the upper (biphenyl, BP) and lower (benzoate, BZ) degradation pathways. The activity of different members of the soil microbial community in performing one or both pathways, and their synergistic interactions during PCB biodegradation, are not well understood. This study investigates BP and BZ biodegradation and subsequent carbon flow through the microbial community in PCB-contaminated soil. DNA stable isotope probing (SIP) was used to identify the bacterial guilds involved in utilizing 13C-biphenyl (unchlorinated analogue of PCBs) and/or 13C-benzoate (product/intermediate of BP degradation and analogue of chlorobenzoates). By performing SIP with two substrates in parallel, we reveal microbes performing the upper (BP) and/or lower (BZ) degradation pathways, and heterotrophic bacteria involved indirectly in processing carbon derived from these substrates (i.e. through crossfeeding). Substrate mineralization rates and shifts in relative abundance of labeled taxa suggest that BP and BZ biotransformations were performed by microorganisms with different growth strategies: BZ-associated bacteria were fast growing, potentially copiotrophic organisms, while microbes that transform BP were oligotrophic, slower growing, organisms. Our findings provide novel insight into the functional interactions of soil bacteria active in processing biphenyl and related aromatic compounds in soil, revealing how carbon flows through a bacterial community. PMID:26915282

  6. Synergistic Processing of Biphenyl and Benzoate: Carbon Flow Through the Bacterial Community in Polychlorinated-Biphenyl-Contaminated Soil

    NASA Astrophysics Data System (ADS)

    Leewis, Mary-Cathrine; Uhlik, Ondrej; Leigh, Mary Beth

    2016-02-01

    Aerobic mineralization of PCBs, which are toxic and persistent organic pollutants, involves the upper (biphenyl, BP) and lower (benzoate, BZ) degradation pathways. The activity of different members of the soil microbial community in performing one or both pathways, and their synergistic interactions during PCB biodegradation, are not well understood. This study investigates BP and BZ biodegradation and subsequent carbon flow through the microbial community in PCB-contaminated soil. DNA stable isotope probing (SIP) was used to identify the bacterial guilds involved in utilizing 13C-biphenyl (unchlorinated analogue of PCBs) and/or 13C-benzoate (product/intermediate of BP degradation and analogue of chlorobenzoates). By performing SIP with two substrates in parallel, we reveal microbes performing the upper (BP) and/or lower (BZ) degradation pathways, and heterotrophic bacteria involved indirectly in processing carbon derived from these substrates (i.e. through crossfeeding). Substrate mineralization rates and shifts in relative abundance of labeled taxa suggest that BP and BZ biotransformations were performed by microorganisms with different growth strategies: BZ-associated bacteria were fast growing, potentially copiotrophic organisms, while microbes that transform BP were oligotrophic, slower growing, organisms. Our findings provide novel insight into the functional interactions of soil bacteria active in processing biphenyl and related aromatic compounds in soil, revealing how carbon flows through a bacterial community.

  7. Biodegradation Processes in a Laboratory-Scale Groundwater Contaminant Plume Assessed by Fluorescence Imaging and Microbial Analysis▿

    PubMed Central

    Rees, Helen C.; Oswald, Sascha E.; Banwart, Steven A.; Pickup, Roger W.; Lerner, David N.

    2007-01-01

    Flow reactors containing quartz sand colonized with biofilm were set up as physical model aquifers to allow degrading plumes of acetate or phenol to be formed from a point source. A noninvasive fluorescent tracer technique was combined with chemical and biological sampling in order to quantify transport and biodegradation processes. Chemical analysis of samples showed a substantial decrease in carbon concentration between the injection and outflow resulting primarily from dilution but also from biodegradation. Two-dimensional imaging of the aqueous oxygen [O2(aq)] concentration field quantified the depletion of O2(aq) within the contaminant plume and provided evidence for microbial respiration associated with biodegradation of the carbon source. Combined microbiological, chemical, and O2(aq) imaging data indicated that biodegradation was greatest at the plume fringe. DNA profiles of bacterial communities were assessed by temperature gradient gel electrophoresis, which revealed that diversity was limited and that community changes observed depended on the carbon source used. Spatial variation in activity within the plume could be quantitatively accounted for by the changes observed in active cell numbers rather than differences in community structure, the total biomass present, or the increased enzyme activity of individual cells. Numerical simulations and comparisons with the experimental data were used to test conceptual models of plume processes. Results demonstrated that plume behavior was best described by growth and decay of active biomass as a single functional group of organisms represented by active cell counts. PMID:17468279

  8. Synergistic Processing of Biphenyl and Benzoate: Carbon Flow Through the Bacterial Community in Polychlorinated-Biphenyl-Contaminated Soil.

    PubMed

    Leewis, Mary-Cathrine; Uhlik, Ondrej; Leigh, Mary Beth

    2016-01-01

    Aerobic mineralization of PCBs, which are toxic and persistent organic pollutants, involves the upper (biphenyl, BP) and lower (benzoate, BZ) degradation pathways. The activity of different members of the soil microbial community in performing one or both pathways, and their synergistic interactions during PCB biodegradation, are not well understood. This study investigates BP and BZ biodegradation and subsequent carbon flow through the microbial community in PCB-contaminated soil. DNA stable isotope probing (SIP) was used to identify the bacterial guilds involved in utilizing (13)C-biphenyl (unchlorinated analogue of PCBs) and/or (13)C-benzoate (product/intermediate of BP degradation and analogue of chlorobenzoates). By performing SIP with two substrates in parallel, we reveal microbes performing the upper (BP) and/or lower (BZ) degradation pathways, and heterotrophic bacteria involved indirectly in processing carbon derived from these substrates (i.e. through crossfeeding). Substrate mineralization rates and shifts in relative abundance of labeled taxa suggest that BP and BZ biotransformations were performed by microorganisms with different growth strategies: BZ-associated bacteria were fast growing, potentially copiotrophic organisms, while microbes that transform BP were oligotrophic, slower growing, organisms. Our findings provide novel insight into the functional interactions of soil bacteria active in processing biphenyl and related aromatic compounds in soil, revealing how carbon flows through a bacterial community. PMID:26915282

  9. Development of a Novel Contamination Resistant Ion Chamber for Process Tritium Measurement and Use in the JET First Trace Tritium Experiment

    SciTech Connect

    Worth, L.B.C.; Pearce, R.J.H.; Bruce, J.; Banks, J.; Scales, S.

    2005-07-15

    The accuracy of process measurements of tritium with conventional ion chambers is often affected by surface tritium contamination. The measurement of tritium in the exhaust of the JET torus is particularly difficult due to surface contamination with highly tritiated hydrocarbons. JET's first unsuccessful attempt to overcome the contamination problem was to use an ion chamber, with a heating element as the chamber wall so that it could be periodically decontaminated by baking. The newly developed ion chamber works on the principle of minimising the surface area within the boundary of the anode and cathode.This paper details the design of the ion chamber, which utilises a grid of 50-micron tungsten wire to define the ion chamber wall and the collector electrode. The effective surface area which, by contamination, is able to effect the measurement of tritium within the process gas has been reduced by a factor of {approx}200 over a conventional ion chamber. It is concluded that the new process ion chamber enables sensitive accurate tritium measurements free from contamination issues. It will be a powerful new tool for future tritium experiments both to improve tritium tracking and to help in the understanding of tritium retention issues.

  10. Sources of Listeria monocytogenes Contamination in a Cold-Smoked Rainbow Trout Processing Plant Detected by Pulsed-Field Gel Electrophoresis Typing

    PubMed Central

    Autio, Tiina; Hielm, Sebastian; Miettinen, Maria; Sjöberg, Anna-Maija; Aarnisalo, Kaarina; Björkroth, Johanna; Mattila-Sandholm, Tiina; Korkeala, Hannu

    1999-01-01

    Sites of Listeria monocytogenes contamination in a cold-smoked rainbow trout (Oncorhynchus mykiss) processing plant were detected by sampling the production line, environment, and fish at different production stages. Two lots were monitored. The frequency of raw fish samples containing L. monocytogenes was low. During processing, the frequency of fish contaminated with L. monocytogenes clearly rose after brining, and the most contaminated sites of the processing plant were the brining and postbrining areas. A total of 303 isolates from the raw fish, product, and the environment were characterized by pulsed-field gel electrophoresis (PFGE). PFGE yielded nine pulsotypes, which formed four clusters. The predominating L. monocytogenes pulsotypes of the final product were associated with brining and slicing, whereas contaminants of raw fish were not detected in the final product. Air-mediated contamination in the plant could not be proved. In accordance with these results, an L. monocytogenes eradication program was planned. The use of hot steam, hot air, and hot water seemed to be useful in eliminating L. monocytogenes. None of the control samples taken in the 5 months after the eradication program was implemented contained L. monocytogenes. PMID:9872773

  11. The Na+/K+ pump is an important modulator of refractoriness and rotor dynamics in human atrial tissue

    PubMed Central

    Sánchez, Carlos; Corrias, Alberto; Bueno-Orovio, Alfonso; Davies, Mark; Swinton, Jonathan; Jacobson, Ingemar; Laguna, Pablo; Pueyo, Esther

    2012-01-01

    Pharmacological treatment of atrial fibrillation (AF) exhibits limited efficacy. Further developments require a comprehensive characterization of ionic modulators of electrophysiology in human atria. Our aim is to systematically investigate the relative importance of ionic properties in modulating excitability, refractoriness, and rotor dynamics in human atria before and after AF-related electrical remodeling (AFER). Computer simulations of single cell and tissue atrial electrophysiology were conducted using two human atrial action potential (AP) models. Changes in AP, refractory period (RP), conduction velocity (CV), and rotor dynamics caused by alterations in key properties of all atrial ionic currents were characterized before and after AFER. Results show that the investigated human atrial electrophysiological properties are primarily modulated by maximal value of Na+/K+ pump current (GNaK) as well as conductances of inward rectifier potassium current (GK1) and fast inward sodium current (GNa). GNaK plays a fundamental role through both electrogenic and homeostatic modulation of AP duration (APD), APD restitution, RP, and reentrant dominant frequency (DF). GK1 controls DF through modulation of AP, APD restitution, RP, and CV. GNa is key in determining DF through alteration of CV and RP, particularly in AFER. Changes in ionic currents have qualitatively similar effects in control and AFER, but effects are smaller in AFER. The systematic analysis conducted in this study unravels the important role of the Na+/K+ pump current in determining human atrial electrophysiology. PMID:22198174

  12. Contaminant Organic Complexes: Their Structure and Energetics in Surface Decontamination Processes

    SciTech Connect

    Satish C. B. Myneni

    2005-12-13

    Siderophores are biological macromolecules (400-2000 Da) released by bacteria in iron limiting situations to sequester Fe from iron oxyhydroxides and silicates in the natural environment. These molecules contain hydroxamate and phenolate functional groups, and exhibit very high affinity for Fe{sup 3+}. While several studies were conducted to understand the behavior of siderophores and their application to the metal sequestration and mineral dissolution, only a few of them have examined the molecular structure of siderophores and their interactions with metals and mineral surfaces in aqueous solutions. Improved understanding of the chemical state of different functional moieties in siderophores can assist in the application of these biological molecules in actinide separation, sequestration and decontamination processes. The focus of our research group is to evaluate the (a) functional group chemistry of selected siderophores and their metal complexes in aqueous solutions, and (b) the nature of siderophore interactions at the mineral-water interfaces. We selected desferrioxamine B (desB), a hydroxamate siderophore, and its small structural analogue, acetohydroxamic acid (aHa), for this investigation. We examined the functional group chemistry of these molecules as a function of pH, and their complexation with aqueous and solid phase Fe(III). For solid phase Fe, we synthesized all naturally occurring Fe(III)-oxyhydroxides (goethite, lepidocrocite, akaganeite, feroxyhite) and hematite. We also synthesized Fe-oxides (goethite and hematite) of different sizes to evaluate the influence of particle size on mineral dissolution kinetics. We used a series of molecular techniques to explore the functional group chemistry of these molecules and their complexes. Infrared spectroscopy is used to specifically identify the variations in oxime group as a function of pH and Fe(III) complexation. Resonance Raman spectroscopy was used to evaluate the nature of hydroxamate binding in

  13. Impact of Scale-Dependent Coupled Processes on Solute Fate and Transport in the Critical Zone: Case Studies Involving Inorganic and Radioactive Contaminants

    NASA Astrophysics Data System (ADS)

    Jardine, P. M.; Gentry, R. W.

    2011-12-01

    Soil, the thin veneer of matter covering the Earths surface that supports a web of living diversity, is often abused through anthropogenic inputs of toxic waste. This subsurface regime, coupled with life sustaining surface water and groundwater is known as the "Critical Zone". The disposal of radioactive and toxic organic and inorganic waste generated by industry and various government agencies has historically involved shallow land burial or the use of surface impoundments in unsaturated soils and sediments. Presently, contaminated sites have been closing rapidly and many remediation strategies have chosen to leave contaminants in-place. As such, contaminants will continue to interact with the geosphere and investigations on long term changes and interactive processes is imperative to verify risks. In this presentation we provide a snap-shot of subsurface science research from the past 25 y that seeks to provide an improved understanding and predictive capability of multi-scale contaminant fate and transport processes in heterogeneous unsaturated and saturated environments. Investigations focus on coupled hydrological, geochemical, and microbial processes that control reactive contaminant transport and that involve multi-scale fundamental research ranging from the molecular scale (e.g. synchrotrons, electron sources, arrays) to in situ plume interrogation strategies at the macroscopic scale (e.g. geophysics, field biostimulation, coupled processes monitoring). We show how this fundamental research is used to provide multi-process, multi-scale predictive monitoring and modeling tools that can be used at contaminated sites to (1) inform and improve the technical basis for decision making, and (2) assess which sites are amenable to natural attenuation and which would benefit from source zone remedial intervention.

  14. Processing capabilties for the elimination of contaminated metal scrapyards at DOE/ORO-managed sites. [Metal smelting facility

    SciTech Connect

    Mack, J.E.; Williams, L.C.

    1982-01-01

    Capabilities exist for reducing all the contaminated nickel, aluminum, and copper scrap to ingot form by smelting. Processing these metals at existing facilities could be completed in about 5 or 6 years. However, these metals represent only about 20% of the total metal inventories currently on hand at the DOE/ORO-managed sites. No provisions have been made for the ferrous scrap. Most of the ferrous scrap is unclassified and does not require secured storage. Also, the potential resale value of the ferrous scrap at about $100 per ton is very low in comparison. Consequently, this scrap has been allowed to accumulate. With several modifications and equipment additions, the induction melter at PGDP could begin processing ferrous scrap after its commitment to nickel and aluminum. The PGDP smelter is a retrofit installation, and annual throughput capabilities are limited. Processing of the existing ferrous scrap inventories would not be completed until the FY 1995-2000 time frame. An alternative proposal has been the installation of induction melters at the other two enrichment facilities. Conceptual design of a generic metal smelting facility is under way. The design study includes capital and operating costs for scrap preparation through ingot storage at an annual throughput of 10,000 tons per year. Facility design includes an induction melter with the capability of melting both ferrous and nonferrous metals. After three years of operation with scrapyard feed, the smelter would have excess capacity to support on-site decontamination and decomissioning projects or upgrading programs. The metal smelting facility has been proposed for FY 1984 line item funding with start-up operations in FY 1986.

  15. Implementation of statistical tools to support identification and management of persistent Listeria monocytogenes contamination in smoked fish processing plants.

    PubMed

    Malley, Thomas J V; Stasiewicz, Matthew J; Gröhn, Yrjö T; Roof, Sherry; Warchocki, Steven; Nightingale, Kendra; Wiedmann, Martin

    2013-05-01

    Listeria monocytogenes persistence in food processing plants is a key source of postprocessing contamination of ready-to-eat foods. Thus, identification and elimination of sites where L. monocytogenes persists (niches) is critical. Two smoked fish processing plants were used as models to develop and implement environmental sampling plans (i) to identify persistent L. monocytogenes subtypes (EcoRI ribotypes) using two statistical approaches and (ii) to identify and eliminate likely L. monocytogenes niches. The first statistic, a binomial test based on ribotype frequencies, was used to evaluate L. monocytogenes ribotype recurrences relative to reference distributions extracted from a public database; the second statistic, a binomial test based on previous positives, was used to measure ribotype occurrences as a risk factor for subsequent isolation of the same ribotype. Both statistics revealed persistent ribotypes in both plants based on data from the initial 4 months of sampling. The statistic based on ribotype frequencies revealed persistence of particular ribotypes at specific sampling sites. Two adaptive sampling strategies guided plant interventions during the study: sampling multiple times before and during processing and vector swabbing (i.e., sampling of additional sites in different directions [vectors] relative to a given site). Among sites sampled for 12 months, a Poisson model regression revealed borderline significant monthly decreases in L. monocytogenes isolates at both plants (P = 0.026 and 0.076). Our data indicate elimination of an L. monocytogenes niche on a food contact surface; niches on nonfood contact surfaces were not eliminated. Although our data illustrate the challenge of identifying and eliminating L. monocytogenes niches, particularly at nonfood contact sites in small and medium plants, the methods for identification of persistence we describe here should broadly facilitate science-based identification of microbial persistence. PMID

  16. New HYDRUS Modules for Simulating Preferential Flow, Colloid-Facilitated Contaminant Transport, and Various Biogeochemical Processes in Soils

    NASA Astrophysics Data System (ADS)

    Simunek, J.; Sejna, M.; Jacques, D.; Langergraber, G.; Bradford, S. A.; van Genuchten, M. Th.

    2012-04-01

    We have dramatically expanded the capabilities of the HYDRUS (2D/3D) software package by developing new modules to account for processes not available in the standard HYDRUS version. These new modules include the DualPerm, C-Hitch, HP2/3, Wetland, and Unsatchem modules. The dual-permeability modeling approach of Gerke and van Genuchten [1993] simulating preferential flow and transport is implemented into the DualPerm module. Colloid transport and colloid-facilitated solute transport, the latter often observed for many contaminants, such as heavy metals, radionuclides, pharmaceuticals, pesticides, and explosives [Šimůnek et al., 2006] are implemented into the C-Hitch module. HP2 and HP3 are the two and three-dimensional alternatives of the HP1 module, currently available with HYDRUS-1D [Jacques and Šimůnek, 2005], that couple HYDRUS flow and transport routines with the generic geochemical model PHREEQC of Parkhurst and Appelo [1999]. The Wetland module includes two alternative approaches (CW2D of Langergraber and Šimůnek [2005] and CWM1 of Langergraber et al. [2009]) for modeling aerobic, anaerobic, and anoxic biogeochemical processes in natural and constructed wetlands. Finally, the Unsatchem module simulates the transport and reactions of major ions in a soil profile. Brief descriptions and an application of each module will be presented. Except for HP3, all modules simulate flow and transport processes in two-dimensional transport domains. All modules are fully supported by the HYDRUS graphical user interface. Further development of these modules, as well as of several other new modules (such as Overland), is still envisioned. Continued feedback from the research community is encouraged.

  17. Molecular-level process governing the interaction of contaminants with iron and manganese oxides. 1998 annual progress report

    SciTech Connect

    Chambers, S.A.; Brown, G.E.

    1998-06-01

    'The authors are carrying out a program of research that focuses on the fundamental mechanisms of redox chemistry of contaminants on mineral surfaces. As much of this chemistry in sediments involves the Fe(III)/Fe(II) and Mn(IV)/Mn(II) couples, they are focusing on mineral phases containing these species. The authors are using a variety of experimental probes, along with molecular modeling theory, to determine clean mineral surface structure and morphology, details of the chemisorption and decomposition of water, and the interface structure and redox chemistry of important contaminants such as CrO{sub 4}{sup -2} on these surfaces. Insight gained in this project will aid in the formulation of more accurate and realistic contaminant-surface complexation and contaminant transport models, and may suggest improved remediation strategies for certain kinds of contaminated soil and groundwater.'

  18. Environmental assessment on a soil washing process of a Pb-contaminated shooting range site: a case study.

    PubMed

    Kim, Do-Hyung; Hwang, Bo-Ram; Moon, Deok-Hyun; Kim, Yong-Seok; Baek, Kitae

    2013-12-01

    In this study, an environmental assessment on a soil washing process for the remediation of a Pb-contaminated shooting range site was conducted, using a green and sustainable remediation tool, i.e., SiteWise ver. 2, based on data relating specifically to the actual remediation project. The entire soil washing process was classified into four major stages, consisting of soil excavation (stage I), physical separation (stage II), acid-based (0.2 N HCl) chemical extraction (stage III), and wastewater treatment (stage IV). Environmental footprints, including greenhouse gas (GHG) emissions, energy consumption, water consumption, and critical air pollutant productions such as PM10, NO x , and SO x , were calculated, and the relative contribution of each stage was analyzed in the environmental assessment. In stage I, the relative contribution of the PM10 emissions was 55.3 % because the soil excavation emitted the fine particles. In stage II, the relative contribution of NO x and SO x emissions was 42.5 and 52.5 %, respectively, which resulted from electricity consumption for the operation of the separator. Stage III was the main contributing factor to 63.1 % of the GHG emissions, 67.5 % of total energy used, and 37.4 % of water consumptions. The relatively high contribution of stage III comes from use of consumable chemicals such as HCl and water-based extraction processes. In stage IV, the relative contributions of GHG emissions, total energy used, and NO x and SO x emissions were 23.2, 19.4, 19.5, and 25.3 %, respectively, which were caused by chemical and electricity demands for system operation. In conclusion, consumable chemicals such as HCl and NaOH, electric energy consumption for system operation, and equipment use for soil excavation were determined to be the major sources of environmental pollution to occur during the soil washing process. Especially, the acid-based chemical extraction process should be avoided in order to improve the sustainability of soil

  19. The Challenges of Preserving Historic Resources During the Deactivation and Decommissioning of Highly Contaminated Historically Significant Plutonium Process Facilities

    SciTech Connect

    Hopkins, A.; Minette, M.; Sorenson, D.; Heineman, R.; Gerber, M.; Charboneau, S.; Bond, F.

    2006-07-01

    The Manhattan Project was initiated to develop nuclear weapons for use in World War II. The Hanford Engineer Works (HEW) was established in eastern Washington State as a production complex for the Manhattan Project. A major product of the HEW was plutonium. The buildings and process equipment used in the early phases of nuclear weapons development are historically significant because of the new and unique work that was performed. When environmental cleanup became Hanford's central mission in 1991, the Department of Energy (DOE) prepared for the deactivation and decommissioning of many of the old process facilities. In many cases, the process facilities were so contaminated, they faced demolition. The National Historic Preservation Act (NHPA) requires federal agencies to evaluate the historic significance of properties under their jurisdiction for eligibility for inclusion in the National Register of Historic Places before altering or demolishing them so that mitigation through documentation of the properties can occur. Specifically, federal agencies are required to evaluate their proposed actions against the effect the actions may have on districts, sites, buildings or structures that are included or eligible for inclusion in the National Register. In an agreement between the DOE's Richland Operations Office (RL), the Washington State Historic Preservation Office (SHPO) and the Advisory Council on Historic Preservation (ACHP), the agencies concurred that the Hanford Site Historic District is eligible for listing on the National Register of Historic Places and that a Site-wide Treatment Plan would streamline compliance with the NHPA while allowing RL to manage the cleanup of the Hanford Site. Currently, many of the old processing buildings at the Plutonium Finishing Plant (PFP) are undergoing deactivation and decommissioning. RL and Fluor Hanford project managers at the PFP are committed to preserving historical artifacts of the plutonium production process. They

  20. CHALLENGES OF PRESERVING HISTORIC RESOURCES DURING THE D & D OF HIGHLY CONTAMINATED HISTORICALLY SIGNIFICANT PLUTONIUM PROCESS FACILITIES

    SciTech Connect

    HOPKINS, A.M.

    2006-03-17

    The Manhattan Project was initiated to develop nuclear weapons for use in World War II. The Hanford Engineer Works (HEW) was established in eastern Washington State as a production complex for the Manhattan Project. A major product of the HEW was plutonium. The buildings and process equipment used in the early phases of nuclear weapons development are historically significant because of the new and unique work that was performed. When environmental cleanup became Hanford's central mission in 1991, the Department of Energy (DOE) prepared for the deactivation and decommissioning of many of the old process facilities. In many cases, the process facilities were so contaminated, they faced demolition. The National Historic Preservation Act (NHPA) requires federal agencies to evaluate the historic significance of properties under their jurisdiction for eligibility for inclusion in the National Register of Historic Places before altering or demolishing them so that mitigation through documentation of the properties can occur. Specifically, federal agencies are required to evaluate their proposed actions against the effect the actions may have on districts, sites, buildings or structures that ere included or eligible for inclusion in the National Register. In an agreement between the DOE'S Richland Operations Office (RL), the Washington State Historic Preservation Office (SHPO) and the Advisory Council on Historic Preservation (ACHP), the agencies concurred that the Hanford Site Historic District is eligible for listing on the National Register of Historic Places and that a Sitewide Treatment Plan would streamline compliance with the NHPA while allowing RL to manage the cleanup of the Hanford Site. Currently, many of the old processing buildings at the Plutonium Finishing Plant (PFP) are undergoing deactivation and decommissioning. RL and Fluor Hanford project managers at the PFP are committed to preserving historical artifacts of the plutonium production process. They

  1. Removal of petroleum hydrocarbons from contaminated groundwater by the combined technique of adsorption onto perlite followed by the O3/H2O2 process.

    PubMed

    Moussavi, Gholamreza; Bagheri, Amir

    2012-09-01

    Groundwater contaminated with petroleum hydrocarbons was treated using a combined system of adsorption onto powdered expanded perlite (PEP) followed by the O3/H2O2 process. The pretreatment investigations indicated a high capacity for PEP to remove petroleum hydrocarbons from the contaminated water. An experimental total petroleum hydrocarbon (TPH) adsorption capacity of 275 mg/g PEP was obtained at the natural pH of water. The experimental data fit best with the Freundlich isotherm model and pseudo-second-order adsorption model. The second phase of the experiment evaluated the performance of the O3/H2O2 process in the removal of residual TPH from pretreated water and compared the results with that of raw water. The O3/H202 process attained a maximum TPH removal rate for the pretreated water after 70 min, when 93% of the residual TPH in the effluent of the adsorption system was removed. Overall, the combination of adsorption onto PEP for 100 min and the subsequent treatment with the O3/H2O2 process for 70min eliminated over 99% of the TPH of highly petroleum-contaminated groundwater, with initial values of 162 mg/L. Therefore, we can conclude that the developed treatment system is an appropriate method of remediation for petroleum-contaminated waters. PMID:23240183

  2. The impact of contaminated biomass for the formation of emission in the combustion process of producer gas in the cogeneration unit

    NASA Astrophysics Data System (ADS)

    Kočanová, Slávka; Lukáč, Ladislav; Széplaky, Dávid; Lazić, Ladislav

    2014-08-01

    The paper presents the measurement result to the equipment designed for utilization contaminated biomass with segregated waste. Presented technology gasification of segregated waste together with biomass shows the optimization process of converting solid fuel to gas and its energy utilization in the cogeneration unit.

  3. Chlorine Stabilizer T-128 enhances efficacy of chlorine against cross contamination by E. coli O157:H7 and Salmonella in fresh-cut lettuce processing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During fresh produce processing, organic materials released from cut tissues can rapidly react with free chlorine in the wash solution, leading to the potential survival of foodborne bacterial pathogens and cross-contamination when the free chlorine is depleted. A reported chlorine stabilizer, T128...

  4. Challenges and Opportunities for Electrochemical Processes as Next-Generation Technologies for the Treatment of Contaminated Water.

    PubMed

    Radjenovic, Jelena; Sedlak, David L

    2015-10-01

    Electrochemical processes have been extensively investigated for the removal of a range of organic and inorganic contaminants. The great majority of these studies were conducted using nitrate-, perchlorate-, sulfate-, and chloride-based electrolyte solutions. In actual treatment applications, organic and inorganic constituents may have substantial effects on the performance of electrochemical treatment. In particular, the outcome of electrochemical oxidation will depend on the concentration of chloride and bromide. Formation of chlorate, perchlorate, chlorinated, and brominated organics may compromise the quality of the treated effluent. A critical review of recent research identifies future opportunities and research needed to overcome major challenges that currently limit the application of electrochemical water treatment systems for industrial and municipal water and wastewater treatment. Given the increasing interest in decentralized wastewater treatment, applications of electrolytic systems for treatment of domestic wastewater, greywater, and source-separated urine are also included. To support future adoption of electrochemical treatment, new approaches are needed to minimize the formation of toxic byproducts and the loss of efficiency caused by mass transfer limitations and undesired side reactions. Prior to realizing these improvements, recognition of the situations where these limitations pose potential health risks is a necessary step in the design and operation of electrochemical treatment systems. PMID:26370517

  5. Dismantling of Highly Contaminated Process Installations of the German Reprocessing Facility (WAK) - Status of New Remote Handling Technology - 13287

    SciTech Connect

    Dux, Joachim; Friedrich, Daniel; Lutz, Werner; Ripholz, Martina

    2013-07-01

    Decommissioning and dismantling of the former German Pilot Reprocessing Plant Karlsruhe (WAK) including the Vitrification Facility (VEK) is being executed in different Project steps related to the reprocessing, HLLW storage and vitrification complexes /1/. While inside the reprocessing building the total inventory of process equipment has already been dismantled and disposed of, the HLLW storage and vitrification complex has been placed out of operation since vitrification and tank rinsing procedures where finalized in year 2010. This paper describes the progress made in dismantling of the shielded boxes of the highly contaminated laboratory as a precondition to get access to the hot cells of the HLLW storage. The major challenges of the dismantling of this laboratory were the high dose rates up to 700 mSv/h and the locking technology for the removal of the hot cell installations. In parallel extensive prototype testing of different carrier systems and power manipulators to be applied to dismantle the HLLW-tanks and other hot cell equipment is ongoing. First experiences with the new manipulator carrier system and a new master slave manipulator with force reflection will be reported. (authors)

  6. Tungsten contamination in ion implantation

    NASA Astrophysics Data System (ADS)

    Polignano, M. L.; Barbarossa, F.; Galbiati, A.; Magni, D.; Mica, I.

    2016-06-01

    In this paper the tungsten contamination in ion implantation processes is studied by DLTS analysis both in typical operating conditions and after contamination of the implanter by implantation of wafers with an exposed tungsten layer. Of course the contaminant concentration is orders of magnitude higher after contamination of the implanter, but in addition our data show that different mechanisms are active in a not contaminated and in a contaminated implanter. A moderate tungsten contamination is observed also in a not contaminated implanter, however in that case contamination is completely not energetic and can be effectively screened by a very thin oxide. On the contrary, the contamination due to an implantation in a previously contaminated implanter is reduced but not suppressed even by a relatively thick screen oxide. The comparison with SRIM calculations confirms that the observed deep penetration of the contaminant cannot be explained by a plain sputtering mechanism.

  7. In situ retreival of contaminants or other substances using a barrier system and leaching solutions and components, processes and methods relating thereto

    DOEpatents

    Nickelson, Reva A.; Walsh, Stephanie; Richardson, John G.; Dick, John R.; Sloan, Paul A.

    2005-06-28

    Processes and methods relating to treating contaminants and collecting desired substances from a zone of interest using subterranean collection and containment barriers. Tubular casings having interlock structures are used to create subterranean barriers for containing and treating buried waste and its effluents. The subterranean barrier includes an effluent collection system. Treatment solutions provided to the zone of interest pass therethrough and are collected by the barrier and treated or recovered, allowing on-site remediation. Barrier components may be used to in the treatment by collecting or removing contaminants or other materials from the zone of interest.

  8. Ionic mechanisms of cardiac cell swelling induced by blocking Na+/K+ pump as revealed by experiments and simulation.

    PubMed

    Takeuchi, Ayako; Tatsumi, Shuji; Sarai, Nobuaki; Terashima, Keisuke; Matsuoka, Satoshi; Noma, Akinori

    2006-11-01

    Although the Na(+)/K(+) pump is one of the key mechanisms responsible for maintaining cell volume, we have observed experimentally that cell volume remained almost constant during 90 min exposure of guinea pig ventricular myocytes to ouabain. Simulation of this finding using a comprehensive cardiac cell model (Kyoto model incorporating Cl(-) and water fluxes) predicted roles for the plasma membrane Ca(2+)-ATPase (PMCA) and Na(+)/Ca(2+) exchanger, in addition to low membrane permeabilities for Na(+) and Cl(-), in maintaining cell volume. PMCA might help maintain the [Ca(2+)] gradient across the membrane though compromised, and thereby promote reverse Na(+)/Ca(2+) exchange stimulated by the increased [Na(+)](i) as well as the membrane depolarization. Na(+) extrusion via Na(+)/Ca(2+) exchange delayed cell swelling during Na(+)/K(+) pump block. Supporting these model predictions, we observed ventricular cell swelling after blocking Na(+)/Ca(2+) exchange with KB-R7943 or SEA0400 in the presence of ouabain. When Cl(-) conductance via the cystic fibrosis transmembrane conductance regulator (CFTR) was activated with isoproterenol during the ouabain treatment, cells showed an initial shrinkage to 94.2 +/- 0.5%, followed by a marked swelling 52.0 +/- 4.9 min after drug application. Concomitantly with the onset of swelling, a rapid jump of membrane potential was observed. These experimental observations could be reproduced well by the model simulations. Namely, the Cl(-) efflux via CFTR accompanied by a concomitant cation efflux caused the initial volume decrease. Then, the gradual membrane depolarization induced by the Na(+)/K(+) pump block activated the window current of the L-type Ca(2+) current, which increased [Ca(2+)](i). Finally, the activation of Ca(2+)-dependent cation conductance induced the jump of membrane potential, and the rapid accumulation of intracellular Na(+) accompanied by the Cl(-) influx via CFTR, resulting in the cell swelling. The pivotal role of L

  9. Salmonella and Escherichia coli contamination of poultry meat from a processing plant and retail markets in Ibadan, Oyo State, Nigeria.

    PubMed

    Adeyanju, Gladys Taiwo; Ishola, Olayinka

    2014-01-01

    Salmonella spp and Escherichia coli are the two most important food-borne pathogens of public health interest incriminated in poultry meat worldwide. This study is to access their levels in frozen poultry meat obtained in Ibadan, Oyo State and compare those obtained from a commercial Nigerian-registered poultry company having a broiler-processing plant, Sayed Farms Ltd(R), with that obtained from retail stores. These retail stores source their products as illegal imports from neighboring Benin Republic or Togo because of a ban imposed by Government policy in Nigeria since July 2002 (USDA, GAIN report #NI2025:1-6, 2002). Microbiological Standards and Guidelines by USDA (National Agricultural library) (USDA 2011) and NCCLS guidelines (from Global Salm-Surv, 2003) were used during the research work. The study was approved by the Ethical Research Review Board (ERRB, Research Management Office 2011), University of Ibadan, Nigeria. A total of one hundred and fifty-two (152) frozen poultry meat samples comprising ninety-nine retail poultry (53 chicken and 46 turkey) and 53 chicken from the processing plant were accessed. ISO Standards catalogue 07.100.30 (2011) was used in accessing the levels of Salmonella, Escherichia coli, Enterobacteriaceae counts and Aerobic plate count. ISO 6579: 2002 was used for Salmonella isolation and ISO-16654:2001 for Escherichia coli isolation. There was a higher level of Aerobic plate counts and Enterobacteriaceae counts in frozen retail poultry meat than from the processing plant. Salmonella contamination from the ninety-nine poultry samples (53 chicken and 46 turkey) obtained from retail markets was at 33% [chicken 32.1% (17/53) and turkey 34.8% (16/46)] while Escherichia coli at 43.4% [chicken 47.2% (25/53) and turkey 39.1% (18/46)]. From the processing plant, twelve (12) Salmonella isolates were obtained and prevalence rate calculated as 22.6% while three (3) Escherichia coli isolates at 5.7% was obtained. Antibiotic sensitivity for

  10. Oxidative inhibition of the vascular Na+-K+ pump via NADPH oxidase-dependent β1-subunit glutathionylation: implications for angiotensin II-induced vascular dysfunction.

    PubMed

    Liu, Chia-Chi; Karimi Galougahi, Keyvan; Weisbrod, Robert M; Hansen, Thomas; Ravaie, Ramtin; Nunez, Andrea; Liu, Yi B; Fry, Natasha; Garcia, Alvaro; Hamilton, Elisha J; Sweadner, Kathleen J; Cohen, Richard A; Figtree, Gemma A

    2013-12-01

    Glutathionylation of the Na(+)-K(+) pump's β1-subunit is a key molecular mechanism of physiological and pathophysiological pump inhibition in cardiac myocytes. Its contribution to Na(+)-K(+) pump regulation in other tissues is unknown, and cannot be assumed given the dependence on specific β-subunit isoform expression and receptor-coupled pathways. As Na(+)-K(+) pump activity is an important determinant of vascular tone through effects on [Ca(2+)]i, we have examined the role of oxidative regulation of the Na(+)-K(+) pump in mediating angiotensin II (Ang II)-induced increases in vascular reactivity. β1-subunit glutathione adducts were present at baseline and increased by exposure to Ang II in rabbit aortic rings, primary rabbit aortic vascular smooth muscle cells (VSMCs), and human arterial segments. In VSMCs, Ang II-induced glutathionylation was associated with marked reduction in Na(+)-K(+)ATPase activity, an effect that was abolished by the NADPH oxidase inhibitory peptide, tat-gp91ds. In aortic segments, Ang II-induced glutathionylation was associated with decreased K(+)-induced vasorelaxation, a validated index of pump activity. Ang II-induced oxidative inhibition of Na(+)-K(+) ATPase and decrease in K(+)-induced relaxation were reversed by preincubation of VSMCs and rings with recombinant FXYD3 protein that is known to facilitate deglutathionylation of β1-subunit. Knock-out of FXYD1 dramatically decreased K(+)-induced relaxation in a mouse model. Attenuation of Ang II signaling in vivo by captopril (8 mg/kg/day for 7 days) decreased superoxide-sensitive DHE levels in the media of rabbit aorta, decreased β1-subunit glutathionylation, and enhanced K(+)-induced vasorelaxation. Ang II inhibits the Na(+)-K(+) pump in VSMCs via NADPH oxidase-dependent glutathionylation of the pump's β1-subunit, and this newly identified signaling pathway may contribute to altered vascular tone. FXYD proteins reduce oxidative inhibition of the Na(+)-K(+) pump and may have an

  11. Response of branchial Na(+)/K(+) ATPase to changes in ambient temperature in Atlantic cod (Gadus morhua) and whiting (Merlangius merlangus).

    PubMed

    Michael, Katharina; Koschnick, Nils; Pörtner, Hans-O; Lucassen, Magnus

    2016-05-01

    The maintenance of ion and pH homeostasis despite changes in ambient temperature is crucial for ectothermic organisms. Thermal sensitivity of Na(+)/K(+) ATPase mRNA expression, protein expression and activity was determined in gills of North Sea cod (NC) and Northeastern Arctic cod (NEAC), acclimated for 6 weeks at 4 and 10 °C and compared to field samples of North Sea cod (sNC), acclimatized to early spring (4 °C) and summer (18 °C) conditions. The same analyses were conducted in gills of the confamiliar whiting, acclimated at 4 and 10 °C. Branchial Na(+)/K(+) ATPase capacities remained uncompensated at functional and protein levels in NC and NEAC at both acclimation temperatures. Na(+)/K(+) ATPase mRNA expression in NEAC acclimated at 10 °C was about twofold higher compared to NC, indicating some population-specific differentiation at this level. Lower Na(+)/K(+) ATPase capacities in gills of warm-acclimatized sNC at common assay temperatures indicate thermal compensation between seasonal extremes, and post-translational modifications contributed to this mitigation at high assay temperature. Together, cod compensates Na(+)/K(+) ATPase capacities on the warm edge of the thermal window and below 4 °C, respectively. In contrast, whiting Na(+)/K(+) ATPase capacities were cold compensated at 4 °C, supported by 1.5-fold higher mRNA and protein expression. Besides, capacities were lower in whiting compared to NC and NEAC at optimum temperature, which may be advantageous in terms of reduced maintenance cost, but at temperatures ≤4 °C, compensation may represent an energy trade-off to maintain homeostasis. The species-specific response of gadid Na(+)/K(+) ATPase indicates certain threshold temperatures beyond which compensation of the pump is elicited, possibly related to the different biogeography of these species. PMID:26922791

  12. Evaluating impacts of pulp and paper mill process changes on bioactive contaminant loading to St. Louis Bay.

    EPA Science Inventory

    As a convergence point for human waste streams, wastewater treatment plants are recognized as point sources through which contaminants originating from domestic, industrial, and commercial activities enter surface waters. Effluent from the Western Lake Superior Sanitary District ...

  13. Application of surrogates, indicators, and high-resolution mass spectrometry to evaluate the efficacy of UV processes for attenuation of emerging contaminants in water

    PubMed Central

    Merel, Sylvain; Anumol, Tarun; Park, Minkyu; Snyder, Shane A.

    2016-01-01

    In response to water scarcity, strategies relying on multiple processes to turn wastewater effluent into potable water are being increasingly considered by many cities. In such context, the occurrence of contaminants as well as their fate during treatment processes is a major concern. Three analytical approaches where used to characterize the efficacy of UV and UV/H2O2 processes on a secondary wastewater effluent. The first analytical approach assessed bulk organic parameters or surrogates before and after treatment, while the second analytical approach measured the removal of specific indicator compounds. Sixteen trace organic contaminants were selected due to their relative high concentration and detection frequency over eight monitoring campaigns. While their removal rate ranges from approximately 10 to >90%, some of these compounds can be used to gauge process efficacy (or failure). The third analytical approach assessed the fate of unknown contaminants through high-resolution time-of-flight (TOF) mass spectrometry with advanced data processing and demonstrated the occurrence of several thousand organic compounds in the water. A heat map clearly evidenced compounds as recalcitrant or transformed by the UV processes applied. In addition, those chemicals with similar fate were able to be grouped together into clusters to identify new indicator compounds. In this manuscript, each approach is evaluated with advantages and disadvantages compared. PMID:25262385

  14. Application of surrogates, indicators, and high-resolution mass spectrometry to evaluate the efficacy of UV processes for attenuation of emerging contaminants in water.

    PubMed

    Merel, Sylvain; Anumol, Tarun; Park, Minkyu; Snyder, Shane A

    2015-01-23

    In response to water scarcity, strategies relying on multiple processes to turn wastewater effluent into potable water are being increasingly considered by many cities. In such context, the occurrence of contaminants as well as their fate during treatment processes is a major concern. Three analytical approaches where used to characterize the efficacy of UV and UV/H2O2 processes on a secondary wastewater effluent. The first analytical approach assessed bulk organic parameters or surrogates before and after treatment, while the second analytical approach measured the removal of specific indicator compounds. Sixteen trace organic contaminants were selected due to their relative high concentration and detection frequency over eight monitoring campaigns. While their removal rate ranges from approximately 10 to >90%, some of these compounds can be used to gauge process efficacy (or failure). The third analytical approach assessed the fate of unknown contaminants through high-resolution time-of-flight (TOF) mass spectrometry with advanced data processing and demonstrated the occurrence of several thousand organic compounds in the water. A heat map clearly evidenced compounds as recalcitrant or transformed by the UV processes applied. In addition, those chemicals with similar fate were grouped together into clusters to identify new indicator compounds. In this manuscript, each approach is evaluated with advantages and disadvantages compared. PMID:25262385

  15. Monitoring priority substances, other organic contaminants and heavy metals in a volcanic aquifer from different sources and hydrological processes.

    PubMed

    Estevez, Esmeralda; Cabrera, María del Carmen; Fernández-Vera, Juan Ramón; Molina-Díaz, Antonio; Robles-Molina, José; Palacios-Díaz, María del Pino

    2016-05-01

    Irrigation with reclaimed water (R) is necessary to guarantee the sustainability of semi-arid areas. Results obtained during a two years monitoring network (2009-2011) in Gran Canaria are presented, including the analysis of chemical parameters, N and S isotopes, priority substances (2008/105/EC, 2013/39/EU), other organic contaminants and heavy metals in groundwater and R used to irrigate a golf course. The aims of this work are to evaluate the contamination in a volcanic aquifer, relate the presence of organic contaminants and heavy metals with the hydrogeochemistry and identify pollution sources in the area. No priority substance exceeded the EU thresholds for surface water, although seventeen were detected in R. The most frequent compounds were hexachlorobenzene, chlorpyrifos ethyl, fluorene, phenanthrene and pyrene. These compounds were detected at low concentration, except chlorpyrifos. Chlorpyrifos ethyl, terbuthylazine, diuron, terbutryn, procymidone, atrazine and propazine exceeded the European threshold concentration for pesticides in groundwater (100ngL(-1)). Therefore, the priority substances chlorpyrifos ethyl and diuron must be included in monitoring studies. The priority pesticides chlorfenvinphos and diazinon were always detected in R but rarely in groundwater. Besides, the existence of contaminants not related to the current R irrigation has been identified. Absence of environmental problems related to heavy metals can be expected. The relationship among contaminant presence, hydrogeochemistry, including the stable isotopic prints of δ(18)O, δ(15)N and δ(34)S and preferential recharge paths has been described. The coastal well shows high values of EC, nitrate, a variable chemistry, and 50% of organic contaminants detected above 100ngL(-1). The well located in the recharge area presents a stable hydrochemistry, the lowest value of δ(15)N and the lowest contaminants occurrence. The area is an example of a complex volcanic media with several

  16. Excitability of the T-tubular system in rat skeletal muscle: roles of K+ and Na+ gradients and Na+-K+ pump activity.

    PubMed

    Nielsen, O B; Ørtenblad, N; Lamb, G D; Stephenson, D G

    2004-05-15

    Strenuous exercise causes an increase in extracellular [K(+)] and intracellular Na(+) ([Na(+)](i)) of working muscles, which may reduce sarcolemma excitability. The excitability of the sarcolemma is, however, to some extent protected by a concomitant increase in the activity of muscle Na(+)-K(+) pumps. The exercise-induced build-up of extracellular K(+) is most likely larger in the T-tubules than in the interstitium but the significance of the cation shifts and Na(+)-K(+) pump for the excitability of the T-tubular membrane and the voltage sensors is largely unknown. Using mechanically skinned fibres, we here study the role of the Na(+)-K(+) pump in maintaining T-tubular function in fibres with reduced chemical K(+) gradient. The Na(+)-K(+) pump activity was manipulated by changing [Na(+)](i). The responsiveness of the T-tubules was evaluated from the excitation-induced force production of the fibres. Compared to control twitch force in fibres with a close to normal intracellular [K(+)] ([K(+)](i)), a reduction in [K(+)](i) to below 60 mM significantly reduced twitch force. Between 10 and 50 mM Na(+), the reduction in force depended on [Na(+)](i), the twitch force at 40 mM K(+) being 22 +/- 4 and 54 +/- 9% (of control force) at a [Na(+)](i) of 10 and 20 mM, respectively (n= 4). Double pulse stimulation of fibres at low [K(+)](i) showed that although elevated [Na(+)](i) increased the responsiveness to single action potentials, it reduced the capacity of the T-tubules to respond to high frequency stimulation. It is concluded that a reduction in the chemical gradient for K(+), as takes place during intensive exercise, may depress T-tubular function, but that a concomitant exercise-induced increase in [Na(+)](i) protects T-tubular function by stimulating the Na(+)-K(+) pump. PMID:15034125

  17. β3-Adrenoceptor activation relieves oxidative inhibition of the cardiac Na+-K+ pump in hyperglycemia induced by insulin receptor blockade

    PubMed Central

    Karimi Galougahi, Keyvan; Liu, Chia-Chi; Garcia, Alvaro; Fry, Natasha A.; Hamilton, Elisha J.; Figtree, Gemma A.

    2015-01-01

    Dysregulated nitric oxide (NO)- and superoxide (O2·−)-dependent signaling contributes to the pathobiology of diabetes-induced cardiovascular complications. We examined if stimulation of β3-adrenergic receptors (β3-ARs), coupled to endothelial NO synthase (eNOS) activation, relieves oxidative inhibition of eNOS and the Na+-K+ pump induced by hyperglycemia. Hyperglycemia was established in male New Zealand White rabbits by infusion of the insulin receptor antagonist S961 for 7 days. Hyperglycemia increased tissue and blood indexes of oxidative stress. It induced glutathionylation of the Na+-K+ pump β1-subunit in cardiac myocytes, an oxidative modification causing pump inhibition, and reduced the electrogenic pump current in voltage-clamped myocytes. Hyperglycemia also increased glutathionylation of eNOS, which causes its uncoupling, and increased coimmunoprecipitation of cytosolic p47phox and membranous p22phox NADPH oxidase subunits, consistent with NADPH oxidase activation. Blocking translocation of p47phox to p22phox with the gp91ds-tat peptide in cardiac myocytes ex vivo abolished the hyperglycemia-induced increase in glutathionylation of the Na+-K+ pump β1-subunit and decrease in pump current. In vivo treatment with the β3-AR agonist CL316243 for 3 days eliminated the increase in indexes of oxidative stress, decreased coimmunoprecipitation of p22phox with p47phox, abolished the hyperglycemia-induced increase in glutathionylation of eNOS and the Na+-K+ pump β1-subunit, and abolished the decrease in pump current. CL316243 also increased coimmunoprecipitation of glutaredoxin-1 with the Na+-K+ pump β1-subunit, which may reflect facilitation of deglutathionylation. In vivo β3-AR activation relieves oxidative inhibition of key cardiac myocyte proteins in hyperglycemia and may be effective in targeting the deleterious cardiac effects of diabetes. PMID:26063704

  18. β3-Adrenoceptor activation relieves oxidative inhibition of the cardiac Na+-K+ pump in hyperglycemia induced by insulin receptor blockade.

    PubMed

    Karimi Galougahi, Keyvan; Liu, Chia-Chi; Garcia, Alvaro; Fry, Natasha A; Hamilton, Elisha J; Figtree, Gemma A; Rasmussen, Helge H

    2015-09-01

    Dysregulated nitric oxide (NO)- and superoxide (O2 (·-))-dependent signaling contributes to the pathobiology of diabetes-induced cardiovascular complications. We examined if stimulation of β3-adrenergic receptors (β3-ARs), coupled to endothelial NO synthase (eNOS) activation, relieves oxidative inhibition of eNOS and the Na(+)-K(+) pump induced by hyperglycemia. Hyperglycemia was established in male New Zealand White rabbits by infusion of the insulin receptor antagonist S961 for 7 days. Hyperglycemia increased tissue and blood indexes of oxidative stress. It induced glutathionylation of the Na(+)-K(+) pump β1-subunit in cardiac myocytes, an oxidative modification causing pump inhibition, and reduced the electrogenic pump current in voltage-clamped myocytes. Hyperglycemia also increased glutathionylation of eNOS, which causes its uncoupling, and increased coimmunoprecipitation of cytosolic p47(phox) and membranous p22(phox) NADPH oxidase subunits, consistent with NADPH oxidase activation. Blocking translocation of p47(phox) to p22(phox) with the gp91ds-tat peptide in cardiac myocytes ex vivo abolished the hyperglycemia-induced increase in glutathionylation of the Na(+)-K(+) pump β1-subunit and decrease in pump current. In vivo treatment with the β3-AR agonist CL316243 for 3 days eliminated the increase in indexes of oxidative stress, decreased coimmunoprecipitation of p22(phox) with p47(phox), abolished the hyperglycemia-induced increase in glutathionylation of eNOS and the Na(+)-K(+) pump β1-subunit, and abolished the decrease in pump current. CL316243 also increased coimmunoprecipitation of glutaredoxin-1 with the Na(+)-K(+) pump β1-subunit, which may reflect facilitation of deglutathionylation. In vivo β3-AR activation relieves oxidative inhibition of key cardiac myocyte proteins in hyperglycemia and may be effective in targeting the deleterious cardiac effects of diabetes. PMID:26063704

  19. Processes influencing the transport and fate of contaminated sediments in the coastal ocean: Boston Harbor and Massachusetts Bay

    USGS Publications Warehouse

    Bothner, Michael H., (Edited By); Butman, Bradford

    2007-01-01

    Most of the major urban centers of the United States including Boston, New York, Washington, Chicago, New Orleans, Miami, Los Angeles, San Francisco, and Seattle—are on a coast (fig. 1.1). All of these cities discharge treated sewage effluent into adjacent waters. In 2000, 74 percent of the U.S. population lived within 200 kilometers (km) of the coast. Between 1980 and 2002, the population density in coastal communities increased approximately 4.5 times faster than in noncoastal areas of the U.S. (Perkins, 2004). More people generate larger volumes of wastes, increase the demands on wastewater treatment, expand the area of impervious land surfaces, and use more vehicles that contribute contaminants to street runoff. According to the National Coastal Condition Report II (U.S. Environmental Protection Agency, 2005a), on the basis of coastal habitat, water and sediment quality, benthic index, and fish tissue, the overall national coastal condition is only poor to fair and the overall coastal condition in the highly populated Northeast is poor. Scientific information helps managers to prioritize and regulate coastal-ocean uses that include recreation, commercial fishing, transportation, waste disposal, and critical habitat for marine organisms. These uses are often in conflict with each other and with environmental concerns. Developing a strategy for managing competing uses while maintaining sustainability of coastal resources requires scientific understanding of how the coastal ocean system behaves and how it responds to anthropogenic influences. This report provides a summary of a multidisciplinary research program designed to improve our understanding of the transport and fate of contaminants in Massachusetts coastal waters. Massachusetts Bay and Boston Harbor have been a focus of U.S. Geological Survey (USGS) research because they provide a diverse geographic setting for developing a scientific understanding of the geology, geochemistry, and oceanography of

  20. Feshbach resonances and weakly bound molecular states of boson-boson and boson-fermion NaK pairs

    NASA Astrophysics Data System (ADS)

    Viel, Alexandra; Simoni, Andrea

    2016-04-01

    We conduct a theoretical study of magnetically induced Feshbach resonances and near-threshold bound states in isotopic NaK pairs. Our calculations accurately reproduce Feshbach spectroscopy data on Na 40K and explain the origin of the observed multiplets in the p wave [Phys. Rev. A 85, 051602(R) (2012), 10.1103/PhysRevA.85.051602]. We apply the model to predict scattering and bound state threshold properties of the boson-boson Na 39K and Na 41K systems. We find that the Na 39K isotopic pair presents broad magnetic Feshbach resonances and favorable ground-state features for producing nonreactive polar molecules by two-photon association. Broad s -wave resonances are also predicted for Na 41K collisions.

  1. Assessment of Chlamydia psittaci Shedding and Environmental Contamination as Potential Sources of Worker Exposure throughout the Mule Duck Breeding Process.

    PubMed

    Hulin, V; Bernard, P; Vorimore, F; Aaziz, R; Cléva, D; Robineau, J; Durand, B; Angelis, L; Siarkou, V I; Laroucau, K

    2016-03-01

    Chlamydia psittaci is an obligate intracellular bacterium responsible for avian chlamydiosis, otherwise known as psittacosis, a zoonotic disease that may lead to severe atypical pneumonia. This study was conducted on seven mule duck flocks harboring asymptomatic birds to explore the circulation and persistence of C. psittaci during the entire breeding process and assess the potential sources of worker exposure. Cloacal swabs and air samples were taken on each occasion requiring humans to handle the birds. In parallel, environmental samples, including dust, water, and soil, were collected. Specific real-time PCR analyses revealed the presence of C. psittaci in all flocks but with three different shedding patterns involving ducks about the age of 4, 8, and 12 weeks with heavy, moderate, and low excretion levels, respectively. Air samples were only positive in flocks harboring heavy shedders. Dust in flocks with heavy or moderate shedders carried chlamydial loads strongly associated with the loads detected in avian and soil samples. Environmental contamination, significantly correlated with shedding dynamics, was considered to be the most probable source of exposure. The high prevalence of bacteriophage Chp1 in all flocks, mostly jointly present with chlamydia, suggests an important factor in C. psittaci persistence, thus creating a greater risk for humans. A survey conducted in these flocks regarding farming practices and activities showed that disinfection seems to be the most promising practice for reducing C. psittaci prevalence in ducks and that the place and the duration of action during operations seem to be potential risk factors. Strict adherence to good practices is strongly recommended. PMID:26712548

  2. Assessment of Chlamydia psittaci Shedding and Environmental Contamination as Potential Sources of Worker Exposure throughout the Mule Duck Breeding Process

    PubMed Central

    Hulin, V.; Bernard, P.; Vorimore, F.; Aaziz, R.; Cléva, D.; Robineau, J.; Durand, B.; Angelis, L.

    2015-01-01

    Chlamydia psittaci is an obligate intracellular bacterium responsible for avian chlamydiosis, otherwise known as psittacosis, a zoonotic disease that may lead to severe atypical pneumonia. This study was conducted on seven mule duck flocks harboring asymptomatic birds to explore the circulation and persistence of C. psittaci during the entire breeding process and assess the potential sources of worker exposure. Cloacal swabs and air samples were taken on each occasion requiring humans to handle the birds. In parallel, environmental samples, including dust, water, and soil, were collected. Specific real-time PCR analyses revealed the presence of C. psittaci in all flocks but with three different shedding patterns involving ducks about the age of 4, 8, and 12 weeks with heavy, moderate, and low excretion levels, respectively. Air samples were only positive in flocks harboring heavy shedders. Dust in flocks with heavy or moderate shedders carried chlamydial loads strongly associated with the loads detected in avian and soil samples. Environmental contamination, significantly correlated with shedding dynamics, was considered to be the most probable source of exposure. The high prevalence of bacteriophage Chp1 in all flocks, mostly jointly present with chlamydia, suggests an important factor in C. psittaci persistence, thus creating a greater risk for humans. A survey conducted in these flocks regarding farming practices and activities showed that disinfection seems to be the most promising practice for reducing C. psittaci prevalence in ducks and that the place and the duration of action during operations seem to be potential risk factors. Strict adherence to good practices is strongly recommended. PMID:26712548

  3. Selectivity of externally facing ion-binding sites in the Na/K pump to alkali metals and organic cations.

    PubMed

    Ratheal, Ian M; Virgin, Gail K; Yu, Haibo; Roux, Benoît; Gatto, Craig; Artigas, Pablo

    2010-10-26

    The Na/K pump is a P-type ATPase that exchanges three intracellular Na(+) ions for two extracellular K(+) ions through the plasmalemma of nearly all animal cells. The mechanisms involved in cation selection by the pump's ion-binding sites (site I and site II bind either Na(+) or K(+); site III binds only Na(+)) are poorly understood. We studied cation selectivity by outward-facing sites (high K(+) affinity) of Na/K pumps expressed in Xenopus oocytes, under voltage clamp. Guanidinium(+), methylguanidinium(+), and aminoguanidinium(+) produced two phenomena possibly reflecting actions at site III: (i) voltage-dependent inhibition (VDI) of outwardly directed pump current at saturating K(+), and (ii) induction of pump-mediated, guanidinium-derivative-carried inward current at negative potentials without Na(+) and K(+). In contrast, formamidinium(+) and acetamidinium(+) induced K(+)-like outward currents. Measurement of ouabain-sensitive ATPase activity and radiolabeled cation uptake confirmed that these cations are external K(+) congeners. Molecular dynamics simulations indicate that bound organic cations induce minor distortion of the binding sites. Among tested metals, only Li(+) induced Na(+)-like VDI, whereas all metals tested except Na(+) induced K(+)-like outward currents. Pump-mediated K(+)-like organic cation transport challenges the concept of rigid structural models in which ion specificity at site I and site II arises from a precise and unique arrangement of coordinating ligands. Furthermore, actions by guanidinium(+) derivatives suggest that Na(+) binds to site III in a hydrated form and that the inward current observed without external Na(+) and K(+) represents cation transport when normal occlusion at sites I and II is impaired. These results provide insights on external ion selectivity at the three binding sites. PMID:20937860

  4. NaK pool-boiler bench-scale receiver durability test: Test results and materials analysis

    SciTech Connect

    Andraka, C.E.; Goods, S.H.; Bradshaw, R.W.; Moreno, J.B.; Moss, T.A.; Jones, S.A.

    1994-06-01

    Pool-boiler reflux receivers have been considered as an alternative to heat pipes for the input of concentrated solar energy to Stirling-cycle engines in dish-Stirling electric generation systems. Pool boilers offer simplicity in design and fabrication. The operation of a full-scale pool-boiler receiver has been demonstrated for short periods of time. However, to generate cost-effective electricity, the receiver must operate Without significant maintenance for the entire system life, as much as 20 to 30 years. Long-term liquid-metal boiling stability and materials compatibility with refluxing NaK-78 is not known and must be determined for the pool boiler receiver. No boiling system has been demonstrated for a significant duration with the current porous boiling enhancement surface and materials. Therefore, it is necessary to simulate the full-scale pool boiler design as much as possible, including flux levels, materials, and operating cycles. On-sun testing is impractical because of the limited test time available. A test vessel was constructed with a porous boiling enhancement surface. The boiling surface consisted of a brazed stainless steel powder with about 50% porosity. The vessel was heated with a quartz lamp array providing about go W/CM2 peak incident thermal flux. The vessel was charged with NaK-78. This allows the elimination of costly electric preheating, both on this test and on fullscale receivers. The vessel was fabricated from Haynes 230 alloy. The vessel operated at 750{degrees}C around the clock, with a 1/2-hour shutdown cycle to ambient every 8 hours. The test completed 7500 hours of lamp-on operation time, and over 1000 startups from ambient. The test was terminated when a small leak in an Inconel 600 thermowell was detected. The test design and data are presented here. Metallurgical analysis of virgin and tested materials has begun, and initial results are also presented.

  5. cAMP stimulates apical exocytosis of the renal Na(+)-K(+)-2Cl(-) cotransporter NKCC2 in the thick ascending limb: role of protein kinase A.

    PubMed

    Caceres, Paulo S; Ares, Gustavo R; Ortiz, Pablo A

    2009-09-11

    The apical renal Na(+)-K(+)-2Cl(-) cotransporter NKCC2 mediates NaCl absorption by the thick ascending limb (TAL) of Henle's loop. cAMP stimulates NKCC2 by enhancing steady-state apical membrane levels of this protein; however, the trafficking and signaling mechanisms by which this occurs have not been studied. Here, we report that stimulation of endogenous cAMP levels with either forskolin/3-isobutyl-1-methylxanthine (IBMX) or the V2 receptor agonist [deamino-Cys(1),d-Arg(8)]vasopressin increases steady-state surface NKCC2 and that the protein kinase A (PKA) inhibitor H-89 blocks this effect. Confocal imaging of apical surface NKCC2 in isolated perfused TALs confirmed a stimulatory effect of cAMP on apical trafficking that was blocked by PKA inhibition. Selective stimulation of PKA with the agonist N(6)-benzoyl-cAMP (500 microm) stimulated steady-state surface NKCC2, whereas the Epac-selective agonist 8-p-chlorophenylthio-2'-O-methyl-cAMP (100 and 250 microm) had no effect. To explore the trafficking mechanism by which cAMP increases apical NKCC2, we measured cumulative apical membrane exocytosis and NKCC2 exocytic insertion in TALs. By monitoring apical FM1-43 fluorescence, we observed rapid stimulation of apical exocytosis (2 min) by forskolin/IBMX. We also found constitutive exocytic insertion of NKCC2 in TALs over time, which was increased by 3-fold in the presence of forskolin/IBMX. PKA inhibition blunted cAMP-stimulated exocytic insertion but did not affect the rate of constitutive exocytosis. We conclude that cAMP stimulates steady-state apical surface NKCC2 by stimulating exocytic insertion and that this process is highly dependent on PKA but not Epac. PMID:19592485

  6. Hydrogen Sulfide Regulates Salt Tolerance in Rice by Maintaining Na(+)/K(+) Balance, Mineral Homeostasis and Oxidative Metabolism Under Excessive Salt Stress.

    PubMed

    Mostofa, Mohammad G; Saegusa, Daisuke; Fujita, Masayuki; Tran, Lam-Son Phan

    2015-01-01

    Being a salt sensitive crop, rice growth and development are frequently affected by soil salinity. Hydrogen sulfide (H2S) has been recently explored as an important priming agent regulating diverse physiological processes of plant growth and development. Despite its enormous prospects in plant systems, the role of H2S in plant stress tolerance is still elusive. Here, a combined pharmacological, physiological and biochemical approach was executed aiming to examine the possible mechanism of H2S in enhancement of rice salt stress tolerance. We showed that pretreating rice plants with H2S donor sodium bisulfide (NaHS) clearly improved, but application of H2S scavenger hypotaurine with NaHS decreased growth and biomass-related parameters under salt stress. NaHS-pretreated salt-stressed plants exhibited increased chlorophyll, carotenoid and soluble protein contents, as well as suppressed accumulation of reactive oxygen species (ROS), contributing to oxidative damage protection. The protective mechanism of H2S against oxidative stress was correlated with the elevated levels of ascorbic acid, glutathione, redox states, and the enhanced activities of ROS- and methylglyoxal-detoxifying enzymes. Notably, the ability to decrease the uptake of Na(+) and the Na(+)/K(+) ratio, as well as to balance mineral contents indicated a role of H2S in ion homeostasis under salt stress. Altogether, our results highlight that modulation of the level of endogenous H2S genetically or exogenously could be employed to attain better growth and development of rice, and perhaps other crops, under salt stress. Furthermore, our study reveals the importance of the implication of gasotransmitters like H2S for the management of salt stress, thus assisting rice plants to adapt to adverse environmental changes. PMID:26734015

  7. Phorbol 12-myristate 13-acetate-induced endocytosis of the Na-K-2Cl cotransporter in MDCK cells is associated with a clathrin-dependent pathway

    PubMed Central

    Mykoniatis, Andreas; Shen, Le; Fedor-Chaiken, Mary; Tang, Jun; Tang, Xu; Worrell, Roger T.; Delpire, Eric; Turner, Jerrold R.; Matlin, Karl S.

    2010-01-01

    In secretory epithelial cells, the basolateral Na+-K+-2Cl− cotransporter (NKCC1) plays a major role in salt and fluid secretion. Our laboratory has identified NKCC1 surface expression as an important regulatory mechanism for Cl− secretion in the colonic crypt cell line T84, a process also present in native human colonic crypts. We previously showed that activation of protein kinase C (PKC) by carbachol and phorbol 12-myristate 13-acetate (PMA) decreases NKCC1 surface expression in T84 cells. However, the specific endocytic entry pathway has not been defined. We used a Madin-Darby canine kidney (MDCK) cell line stably transfected with enhanced green fluorescent protein (EGFP)-NKCC1 to map NKCC1 entry during PMA exposure. At given times, we fixed and stained the cells with specific markers (e.g., dynamin II, clathrin heavy chain, and caveolin-1). We also used chlorpromazine, methyl-β-cyclodextrin, amiloride, and dynasore, blockers of the clathrin, caveolin, and macropinocytosis pathways and the vesicle “pinchase” dynamin, respectively. We found that PMA caused dose- and time-dependent NKCC1 endocytosis. After 2.5 min of PMA exposure, ∼80% of EGFP-NKCC1 endocytic vesicles colocalized with clathrin and ∼40% colocalized with dynamin II and with the transferrin receptor, the uptake of which is also mediated by clathrin-coated vesicles. We did not observe significant colocalization of EGFP-NKCC1 endocytic vesicles with caveolin-1, a marker of the caveolae-mediated endocytic pathway. We quantified the effect of each inhibitor on PMA-induced EGFP-NKCC1 endocytosis and found that only chlorpromazine and dynasore caused significant inhibition compared with the untreated control (61% and 25%, respectively, at 2.5 min). Together, these results strongly support the conclusion that PMA-stimulated NKCC1 endocytosis is associated with a clathrin pathway. PMID:19864322

  8. Hydrogen Sulfide Regulates Salt Tolerance in Rice by Maintaining Na+/K+ Balance, Mineral Homeostasis and Oxidative Metabolism Under Excessive Salt Stress

    PubMed Central

    Mostofa, Mohammad G.; Saegusa, Daisuke; Fujita, Masayuki; Tran, Lam-Son Phan

    2015-01-01

    Being a salt sensitive crop, rice growth and development are frequently affected by soil salinity. Hydrogen sulfide (H2S) has been recently explored as an important priming agent regulating diverse physiological processes of plant growth and development. Despite its enormous prospects in plant systems, the role of H2S in plant stress tolerance is still elusive. Here, a combined pharmacological, physiological and biochemical approach was executed aiming to examine the possible mechanism of H2S in enhancement of rice salt stress tolerance. We showed that pretreating rice plants with H2S donor sodium bisulfide (NaHS) clearly improved, but application of H2S scavenger hypotaurine with NaHS decreased growth and biomass-related parameters under salt stress. NaHS-pretreated salt-stressed plants exhibited increased chlorophyll, carotenoid and soluble protein contents, as well as suppressed accumulation of reactive oxygen species (ROS), contributing to oxidative damage protection. The protective mechanism of H2S against oxidative stress was correlated with the elevated levels of ascorbic acid, glutathione, redox states, and the enhanced activities of ROS- and methylglyoxal-detoxifying enzymes. Notably, the ability to decrease the uptake of Na+ and the Na+/K+ ratio, as well as to balance mineral contents indicated a role of H2S in ion homeostasis under salt stress. Altogether, our results highlight that modulation of the level of endogenous H2S genetically or exogenously could be employed to attain better growth and development of rice, and perhaps other crops, under salt stress. Furthermore, our study reveals the importance of the implication of gasotransmitters like H2S for the management of salt stress, thus assisting rice plants to adapt to adverse environmental changes. PMID:26734015

  9. Source tracking of Escherichia coli O157:H7 and Salmonella contamination in the lairage environment at commercial U.S. beef processing plants and identification of an effective intervention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The main source of beef carcass contamination during processing has been identified as the hide. Transportation from the feedlot and lairage at the processing plant have been identified as potential sources of E. coli O157:H7 and Salmonella hide contamination. The objective of this study was to pe...

  10. Transfer of contaminants from surface to hands: experimental assessment of linearity of the exposure process, adherence to the skin, and area exposed during fixed pressure and repeated contact with surfaces contaminated with a powder.

    PubMed

    Brouwer, D H; Kroese, R; Van Hemmen, J J

    1999-04-01

    Estimation of dermal exposure in the workplace resulting from contact with contaminated surfaces is important in risk assessment. Models have been developed to describe the process of exposure due to transfer, but for major input parameters--that is, contact area surface and adherence--defaults are used. This study examines the effect of one single-hand press contact and repeated contacts with a contaminated glass plate on both skin area exposed and loading of the skin for three volunteers. A fluorescent whitening agent was used to study the process of exposure and to determine the increase of the area exposed as well as the adherence of the compound to the skin surface after 1 to 12 consecutive contacts by a video imaging technique. In addition, loading of the skin after 12 contacts was compared to loading of a cotton glove monitor with similar hand pressures. The results show that after one single-hand contact only 4 to 16 percent of the total surface of the palm of the hand was exposed, whereas after 12 contacts this was increased to about 40 percent. The efficiency of transfer was < or = 2 percent of the contamination of the surface. The adherence to the skin was 1.07 micrograms/cm2 after 12 contacts and tended to increase non-linearly with increase in contacts. Because defaults of adherence for use in exposure models are generally a factor 500 to 5,000 higher, and the area exposed is assumed to be the total surface of the hand, overestimation of dermal exposure due to a single hand-surface contact in workplaces may occur. Therefore, additional studies on multi-contact exposure scenarios are indicated to adjust defaults for hand-surface transfer processes. PMID:10457645

  11. Application of the base catalyzed decomposition process to treatment of PCB-contaminated insulation and other materials associated with US Navy vessels. Final report

    SciTech Connect

    Schmidt, A.J.; Zacher, A.H.; Gano, S.R.

    1996-09-01

    The BCD process was applied to dechlorination of two types of PCB-contaminated materials generated from Navy vessel decommissioning activities at Puget Sound Naval Shipyard: insulation of wool felt impregnated with PCB, and PCB-containing paint chips/debris from removal of paint from metal surfaces. The BCD process is a two-stage, low-temperature chemical dehalogenation process. In Stage 1, the materials are mixed with sodium bicarbonate and heated to 350 C. The volatilized halogenated contaminants (eg, PCBs, dioxins, furans), which are collected in a small volume of particulates and granular activated carbon, are decomposed by the liquid-phase reaction (Stage 2) in a stirred-tank reactor, using a high-boiling-point hydrocarbon oil as the reaction medium, with addition of a hydrogen donor, a base (NaOH), and a catalyst. The tests showed that treating wool felt insulation and paint chip wastes with Stage 2 on a large scale is feasible, but compared with current disposal costs for PCB-contaminated materials, using Stage 2 would not be economical at this time. For paint chips generated from shot/sand blasting, the solid-phase BCD process (Stage 1) should be considered, if paint removal activities are accelerated in the future.

  12. Back contamination.

    NASA Technical Reports Server (NTRS)

    Phillips, G. B.

    1971-01-01

    Discussion of the concept and implications of back contamination and of the ways and means for its prevention. Back contamination is defined as contamination of the terrestrial biosphere with organisms or materials returned from outer space that are capable of potentially harmful terrestrial activity. Since the question of whether or not life exists on other planets may, in reality, not be answered until many samples are returned to earth for detailed study, requirements for the prevention of back contamination are necessary. A review of methods of microbiologic contamination control is followed by a discussion of the nature of back contamination and its risk levels, contamination sources and locations, and possible defenses against back contamination. The U.S. lunar back contamination program is described and shown to provide a valuable basis for further refining the technology for the control of planetary back contamination.

  13. Remediation of dinitrotoluene contaminated soils from former ammunition plants: soil washing efficiency and effective process monitoring in bioslurry reactors.

    PubMed

    Zhang, C; Daprato, R C; Nishino, S F; Spain, J C; Hughes, J B

    2001-10-12

    A pilot-scale bioslurry system was used to test the treatment of soils highly contaminated with 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT). The treatment scheme involved a soil-washing process followed by two sequential aerobic slurry reactors augmented with 2,4-DNT- and 2,6-DNT-mineralizing bacteria. Test soils were obtained from two former army ammunition plants, the Volunteer Army Ammunition Plant (VAAP, Chattanooga, TN) and the Badger Army Ammunition Plant (BAAP, Baraboo, WI). Soil washing was used to minimize operational problems in slurry reactors associated with large particulates. The Eimco slurry reactors were operated in a draw-and-fill mode for 3 months and were monitored for the biodegradation of 2,4-DNT and 2,6-DNT, nitrite production, NaOH consumption, and oxygen uptake rate. Results show that soil washing was very effective for the removal of sands and the recovery of soil fines containing 2,4-DNT and 2,6-DNT. Bioslurry reactors offered rapid and nearly complete degradation of both DNT isomers, but require real time monitoring to avoid long lag periods upon refeeding. Results found a significant discrepancy between the measured DNT concentrations and calculated DNT concentrations in the slurry reactors because of solids profiles in the slurry reactors and the presence of floating crystal of DNTs. Based on the actual amount of dinitrotoluene degradation, nitrite release, NaOH consumption, and oxygen uptake were close to the theoretical stoichiometric coefficients of complete DNT mineralization. Such stoichiometric relationships were not achieved if the calculation was based on the measured DNT concentrations due to the heterogeneity of DNT in the reactor. Results indicate that nitrite release, NaOH consumption, and oxygen uptake rates provide a fast assessment of 2,4-DNT degradation and microbial activity in a slurry reactor, but could not be extended to a second reactor in series where the degradation of a much lower concentration

  14. Soil processes and tree growth at shooting ranges in a boreal forest reflect contamination history and lead-induced changes in soil food webs.

    PubMed

    Selonen, Salla; Setälä, Heikki

    2015-06-15

    The effects of shooting-derived lead (Pb) on the structure and functioning of a forest ecosystem, and the recovery of the ecosystem after range abandonment were studied at an active shotgun shooting range, an abandoned shooting range where shooting ceased 20 years earlier and an uncontaminated control site. Despite numerous lead-induced changes in the soil food web, soil processes were only weakly related to soil food web composition. However, decomposition of Scots pine (Pinus sylvestris) needle litter was retarded at the active shooting range, and microbial activity, microbial biomass and the rate of decomposition of Pb-contaminated grass litter decreased with increasing soil Pb concentrations. Tree (P. sylvestris) radial growth was suppressed at the active shooting range right after shooting activities started. In contrast, the growth of pines improved at the abandoned shooting range after the cessation of shooting, despite reduced nitrogen and phosphorus contents of the needles. Higher litter degradation rates and lower Pb concentrations in the topmost soil layer at the abandoned shooting range suggest gradual recovery after range abandonment. Our findings suggest that functions in lead-contaminated coniferous forest ecosystems depend on the successional stage of the forest as well as the time since the contamination source has been eliminated, which affects, e.g., the vertical distribution of the contaminant in the soil. However, despite multiple lead-induced changes throughout the ecosystem, the effects were rather weak, indicating high resistance of coniferous forest ecosystems to this type of stress. PMID:25770944

  15. Demonstration of ATG Process for Stabilizing Mercury (<260 ppm) Contaminated Mixed Waste. Mixed Waste Focus Area. OST Reference # 2407

    SciTech Connect

    None, None

    1999-09-01

    Mercury contaminated wastes in many forms are present at various U. S. Department of Energy (DOE) sites. Based on efforts led by the Mixed Waste Focus Area (MWFA) and its Mercury Working Group (HgWG), the inventory of wastes contaminated with <260 ppm mercury and with radionuclides stored at various DOE sites is estimated to be approximately 6,000 m3). At least 26 different DOE sites have this type of mixed low-level waste in their storage facilities. Extraction methods are required to remove mercury from waste containing >260 ppm levels, but below 260 ppm Hg contamination levels the U. S. Environmental Protection Agency (EPA) does not require removal of mercury from the waste. Steps must still be taken, however, to ensure that the final waste form does not leach mercury in excess of the limit for mercury prescribed in the Resource Conservation and Recovery Act (RCRA) when subjected to the Toxicity Characteristic Leaching Procedure (TCLP). At this time, the limit is 0.20 mg/L. However, in the year 2000, the more stringent Universal Treatment Standard (UTS) of 0.025 mg/L will be used as the target endpoint. Mercury contamination in the wastes at DOE sites presents a challenge because it exists in various forms, such as soil, sludges, and debris, as well as in different chemical species of mercury. Stabilization is of interest for radioactively contaminated mercury waste (<260 ppm Hg) because of its success with particular wastes, such as soils, and its promise of applicability to a broad range of wastes. However, stabilization methods must be proven to be adequate to meet treatment standards. It must also be proven feasible in terms of economics, operability, and safety. To date, no standard method of stabilization has been developed and proven for such varying waste types as those within the DOE complex.

  16. Subsurface characterization of groundwater contaminated by landfill leachate using microbial community profile data and a nonparametric decision-making process

    NASA Astrophysics Data System (ADS)

    Pearce, Andrea R.; Rizzo, Donna M.; Mouser, Paula J.

    2011-06-01

    Microbial biodiversity in groundwater and soil presents a unique opportunity for improving characterization and monitoring at sites with multiple contaminants, yet few computational methods use or incorporate these data because of their high dimensionality and variability. We present a systematic, nonparametric decision-making methodology to help characterize a water quality gradient in leachate-contaminated groundwater using only microbiological data for input. The data-driven methodology is based on clustering a set of molecular genetic-based microbial community profiles. Microbes were sampled from groundwater monitoring wells located within and around an aquifer contaminated with landfill leachate. We modified a self-organizing map (SOM) to weight the input variables by their relative importance and provide statistical guidance for classifying sample similarities. The methodology includes the following steps: (1) preprocessing the microbial data into a smaller number of independent variables using principal component analysis, (2) clustering the resulting principal component (PC) scores using a modified SOM capable of weighting the input PC scores by the percent variance explained by each score, and (3) using a nonparametric statistic to guide selection of appropriate groupings for management purposes. In this landfill leachate application, the weighted SOM assembles the microbial community data from monitoring wells into groupings believed to represent a gradient of site contamination that could aid in characterization and long-term monitoring decisions. Groupings based solely on microbial classifications are consistent with classifications of water quality from hydrochemical information. These microbial community profile data and improved decision-making strategy compliment traditional chemical groundwater analyses for delineating spatial zones of groundwater contamination.

  17. Footprint Reduction Process: Using Remote Sensing and GIS Technologies to Identify Non-Contaminated Land Parcels on the Oak Ridge Reservation National Priorities List Site

    SciTech Connect

    Halsey, P.A.; Kendall, D.T.; King, A.L.; Storms, R.A.

    1998-12-09

    In 1989, the Agency for Toxic Substances and Disease Registry evaluated the entire 35,000-acre U. S: Department of Energy (DOE) Oak Ridge Reservation (ORR, located in Oak Ridge, TN) and placed it on the National Priorities List (NPL), making the ORR subject to Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) regulations. Although much of the ORR has not been impacted by previous federal activities, without investigation it is difficult to discern which parcels of land are free of surface contamination. In 1996, the DOE Oak Ridge Environmental Management Program (EM) funded the Footprint Reduction Project to: 1) develop a process to study the large areas of the ORR that are believed to be free of surface contamination and 2) initiate the delisting of the "clean" areas from the NPL. Although this project's goals do not include the transfer of federal property to non-federal entities, the process development team aimed to provide a final product with multiple uses. Therefore, the process was developed to meet the requirements of NPL delisting and the transfer of non- contaminated federal lands to future land users. Section 120 (h) of the CERCLA law identifies the requirements for the transfer of federal property that is currently part of an NPL site. Reviews of historical information (including aerial photography), field inspections, and the recorded chain of title documents for the property are required for the delisting of property prior to transfer from the federal government. Despite the widespread availability of remote sensing and other digital geographic data and geographic information systems (GIS) for the analysis of such data, historical aerial photography is the only geographic data source required for review under the CERCLA 120 (h) process. However, since the ORR Environmental Management Program had an established Remote Sensing Program, the Footprint Reduction Project included the development and application of a methodology

  18. Post-consumer contamination in high-density polyethylene (HDPE) milk bottles and the design of a bottle-to-bottle recycling process.

    PubMed

    Welle, F

    2005-10-01

    Six hundred conventional recycled HDPE flake samples, which were recollected and sorted in the UK, were screened for post-consumer contamination levels. Each analysed sample consisted of 40-50 individual flakes so that the amount of analysed individual containers was in the range 24,000-30,000 post-consumer milk bottles. Predominant contaminants in hot-washed flake samples were unsaturated oligomers, which can be also be found in virgin high-density polyethylene (HDPE) pellet samples used for milk bottle production. In addition, the flavour compound limonene, the degradation product of antioxidant additives di-tert-butylphenol and low amounts of saturated oligomers were found in higher concentrations in the post-consumer samples in comparison with virgin HDPE. However, the overall concentrations in post-consumer recycled samples were similar to or lower than concentration ranges in comparison with virgin HDPE. Contamination with other HDPE untypical compounds was rare and was in most cases related to non-milk bottles, which are <2.1% of the input material of the recycling process. The maximum concentration found in one sample of 1 g was estimated as 130 mg kg(-1), which corresponds to a contamination of 5200-6500 mg kg(-1) in the individual bottle. The recycling process investigated was based on an efficient sorting process, a hot-washing of the ground bottles, and a further deep-cleaning of the flakes with high temperatures and vacuum. Based on the fact that the contamination levels of post-consumer flake samples are similar to virgin HDPE and on the high cleaning efficiency of the super-clean recycling process especially for highly volatile compounds, the recycling process investigated is suitable for recycled post-consumer HDPE bottles for direct food-contact applications. However, hand-picking after automatically sorting is recommended to decrease the amount of non-milk bottles. The conclusions for suitability are valid, provided that the migration testing of

  19. Contaminant hydrogeology

    SciTech Connect

    Fetter, C.W.

    1993-01-01

    Hydrogeology is a rapidly evolving field in which new approaches and tools are being applied to solve problems. This new book fills an important niche. Fetter focuses primarily on chemical processes in the subsurface, avoiding duplication of materials that are covered in other, more classical texts. This book is an excellent follow-up to his earlier text, Applied Hydrogeology, and reviews only briefly the foundational concepts covered in the earlier textbook. Contaminant Hydrogeology is written at the graduate student level and assumes prerequisite courses in physics, chemistry, and hydrogeology. For the most part, each of the nine chapters covers a major area of concern common to applied contaminant studies. A thorough, theoretical treatment of solute transport through the vadose zone is presented, and a sample problem and a case study add unusually high value to this discussion of a topic that generally is not well understood in the practice. Topics covered include the Buckingham Flux Law, the Richards Equation, vapor-phase transport, equilibrium and nonequilibrium models of mass transport, and preferential flow paths. Nonaqueous-phase liquid migrations under both saturated and unsaturated conditions is covered for horizontal as well as vertical migration. Both light and dense nonaqueous phase liquids are presented, and Darcy's Law for two-phase flow is introduced. The strength of Contaminant Hydrogeology lies in the author's ability to translate concepts through practical experience. This book links the theoretical to the practical through example problems and case histories. It should be considered for use in graduate classes and would be a valuable reference in the library of any practicing hydrogeologist.

  20. Contamination Control Techniques

    SciTech Connect

    EBY, J.L.

    2000-05-16

    Welcome to a workshop on contamination Control techniques. This work shop is designed for about two hours. Attendee participation is encouraged during the workshop. We will address different topics within contamination control techniques; present processes, products and equipment used here at Hanford and then open the floor to you, the attendees for your input on the topics.

  1. Contamination analysis unit

    DOEpatents

    Gregg, H.R.; Meltzer, M.P.

    1996-05-28

    The portable Contamination Analysis Unit (CAU) measures trace quantities of surface contamination in real time. The detector head of the portable contamination analysis unit has an opening with an O-ring seal, one or more vacuum valves and a small mass spectrometer. With the valve closed, the mass spectrometer is evacuated with one or more pumps. The O-ring seal is placed against a surface to be tested and the vacuum valve is opened. Data is collected from the mass spectrometer and a portable computer provides contamination analysis. The CAU can be used to decontaminate and decommission hazardous and radioactive surfaces by measuring residual hazardous surface contamination, such as tritium and trace organics. It provides surface contamination data for research and development applications as well as real-time process control feedback for industrial cleaning operations and can be used to determine the readiness of a surface to accept bonding or coatings. 1 fig.

  2. Organic contaminant separator

    DOEpatents

    Del Mar, Peter; Hemberger, Barbara J.

    1991-01-01

    A process of sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium by (a) passing an initial aqueous medium including a minor amount of the organic contaminant through a polyolefin tube having an internal diameter of from about 0.01 to about 2.0 millimeters and being of sufficient length to permit the organic contaminant to adhere to the tube, (b) passing a solvent through the tube, said solvent capable of separating the adhered organic contaminant from the tube. Further, a chromatographic apparatus for sample preparation prior to analysis for the concentration of an organic contaminant in an aqueous medium, said apparatus including a polyolefin tube having an internal diameter of from about 0.01 to about 2.0 millimeters and being of sufficient length to permit an organic contaminant contained within an aqueous medium passed therethrough to adhere to the tube is disclosed.

  3. Contamination analysis unit

    DOEpatents

    Gregg, Hugh R.; Meltzer, Michael P.

    1996-01-01

    The portable Contamination Analysis Unit (CAU) measures trace quantifies of surface contamination in real time. The detector head of the portable contamination analysis unit has an opening with an O-ring seal, one or more vacuum valves and a small mass spectrometer. With the valve closed, the mass spectrometer is evacuated with one or more pumps. The O-ring seal is placed against a surface to be tested and the vacuum valve is opened. Data is collected from the mass spectrometer and a portable computer provides contamination analysis. The CAU can be used to decontaminate and decommission hazardous and radioactive surface by measuring residual hazardous surface contamination, such as tritium and trace organics It provides surface contamination data for research and development applications as well as real-time process control feedback for industrial cleaning operations and can be used to determine the readiness of a surface to accept bonding or coatings.

  4. Na+/K+/2Cl- cotransporter and CFTR gill expression after seawater transfer in smolts (0+) of different Atlantic salmon (Salmo salar) families

    USGS Publications Warehouse

    Mackie, P.M.; Gharbi, K.; Ballantyne, J.S.; McCormick, S.D.; Wright, P.A.

    2007-01-01

    Smoltification involves morphological and physiological changes in the gills that prepare anadromous salmonids to osmoregulate efficiently in seawater. In a previous study, we found that different families of Atlantic salmon (Salmo salar) smolts vary in their ability to osmoregulate when abruptly transferred to cold seawater and that these differences are correlated with gill Na+/K+ ATPase activity. Here we extend these findings to test whether other key transport proteins, namely Na+/K+/2Cl- contransporter (NKCC) and the Cl- channel or cystic fibrosis transmembrane conductance regulator (CFTR), play a significant role in osmoregulatory differences between families. To facilitate molecular analysis of NKCC, we first isolated a gill cDNA containing the complete coding region (1147 aa) of an isoform previously reported as a partial sequence. Phylogenetic analysis showed that this isoform is most closely related to isoforms of the NKCC1a subfamily found in European eel and Mozambique tilapia. In a second step, we quantified NKCC protein abundance as well as mRNA expression levels for NKCC1a and two CFTR isoforms (CFTRI and CFTRII) in 0+ smolts from three families prior to and following seawater transfer. The family with the lowest salinity tolerance also showed significant increases in gill NKCC1a mRNA after seawater transfer. Taken together with our previous study, these data indicate that family differences in expression of transport proteins are in part related to salinity tolerance, although the best indicator of osmoregulatory performance between families may be gill Na+/K+ ATPase activity and CFTR I mRNA levels, rather than Na+/K+ ATPase and NKCC1a mRNA levels or NKCC protein abundance. ?? 2007 Elsevier B.V. All rights reserved.

  5. Development of an Integrated Multi-Contaminant Removal Process Applied to Warm Syngas Cleanup for Coal-Based Advanced Gasification Systems

    SciTech Connect

    Meyer, Howard

    2010-11-30

    This project met the objective to further the development of an integrated multi-contaminant removal process in which H2S, NH3, HCl and heavy metals including Hg, As, Se and Cd present in the coal-derived syngas can be removed to specified levels in a single/integrated process step. The process supports the mission and goals of the Department of Energy's Gasification Technologies Program, namely to enhance the performance of gasification systems, thus enabling U.S. industry to improve the competitiveness of gasification-based processes. The gasification program will reduce equipment costs, improve process environmental performance, and increase process reliability and flexibility. Two sulfur conversion concepts were tested in the laboratory under this project, i.e., the solventbased, high-pressure University of California Sulfur Recovery Process High Pressure (UCSRP-HP) and the catalytic-based, direct oxidation (DO) section of the CrystaSulf-DO process. Each process required a polishing unit to meet the ultra-clean sulfur content goals of <50 ppbv (parts per billion by volume) as may be necessary for fuel cells or chemical production applications. UCSRP-HP was also tested for the removal of trace, non-sulfur contaminants, including ammonia, hydrogen chloride, and heavy metals. A bench-scale unit was commissioned and limited testing was performed with simulated syngas. Aspen-Plus®-based computer simulation models were prepared and the economics of the UCSRP-HP and CrystaSulf-DO processes were evaluated for a nominal 500 MWe, coal-based, IGCC power plant with carbon capture. This report covers the progress on the UCSRP-HP technology development and the CrystaSulf-DO technology.

  6. Sources and processes of contaminant loss from an intensively grazed catchment inferred from patterns in discharge and concentration of thirteen analytes using high intensity sampling

    NASA Astrophysics Data System (ADS)

    Holz, G. K.

    2010-03-01

    SummaryContaminants in water from intensively grazed catchments have been shown to cause significant environmental impacts. Effective intervention to reduce contaminant loads depends on identifying their sources and processes of mobilisation and transport. In this study, flow ( Q) and analyte concentrations ( CA) from a 12 ha catchment in north-west Tasmania used for grazing dairy cattle were monitored at a fine temporal scale and used to infer sources and processes of loss. Three groups of analytes identified based on CA- Q relationships, which included hysteresis loops, demonstrated that the TP group (TP, DRP, TSS, TN, E.coli and Enterococcus) was transported by surface runoff processes while the behaviour of the NO 3 group (NO 3, TDS, Ca, Mg, Na) was explained by subsurface processes and pathways. The NH 4 group (NH 4, K) was dominated by the addition of large quantities of analyte from grazing. In addition to the CA- Q relationships, concentrations of most analytes decreased linearly over each season of runoff. NH 4 and K concentrations decreased exponentially following grazing events while TP concentrations decreased linearly. The study demonstrated the importance of understanding surface water and groundwater interactions and that relationships between runoff events, analyte concentrations and management as revealed by a fine temporal sampling regime may yield significant insights to sources and processes of loss of analytes in surface flow, at a given scale.

  7. Tracking an Escherichia coli O157:H7-contaminated batch of leafy greens through a pilot-scale fresh-cut processing line.

    PubMed

    Buchholz, Annemarie L; Davidson, Gordon R; Marks, Bradley P; Todd, Ewen C D; Ryser, Elliot T

    2014-09-01

    Cross-contamination of fresh-cut leafy greens with residual Escherichia coli O157:H7-contaminated product during commercial processing was likely a contributing factor in several recent multistate outbreaks. Consequently, radicchio was used as a visual marker to track the spread of the contaminated product to iceberg lettuce in a pilot-scale processing line that included a commercial shredder, step conveyor, flume tank, shaker table, and centrifugal dryer. Uninoculated iceberg lettuce (45 kg) was processed, followed by 9.1 kg of radicchio (dip inoculated to contain a four-strain, green fluorescent protein-labeled nontoxigenic E. coli O157:H7 cocktail at 10(6) CFU/g) and 907 kg (2,000 lb) of uninoculated iceberg lettuce. After collecting the lettuce and radicchio in about 40 bags (∼22.7 kg per bag) along with water and equipment surface samples, all visible shreds of radicchio were retrieved from the bags of shredded product, the equipment, and the floor. E. coli O157:H7 populations were quantified in the lettuce, water, and equipment samples by direct plating with or without prior membrane filtration on Trypticase soy agar containing 0.6% yeast extract and 100 ppm of ampicillin. Based on triplicate experiments, the weight of radicchio in the shredded lettuce averaged 614.9 g (93.6%), 6.9 g (1.3%), 5.0 g (0.8%), and 2.8 g (0.5%) for bags 1 to 10, 11 to 20, 21 to 30, and 31 to 40, respectively, with mean E. coli O157:H7 populations of 1.7, 1.2, 1.1, and 1.1 log CFU/g in radicchio-free lettuce. After processing, more radicchio remained on the conveyor (9.8 g; P < 0.05), compared with the shredder (8.3 g), flume tank (3.5 g), and shaker table (0.1 g), with similar E. coli O157:H7 populations (P > 0.05) recovered from all equipment surfaces after processing. These findings clearly demonstrate both the potential for the continuous spread of contaminated lettuce to multiple batches of product during processing and the need for improved equipment designs that minimize

  8. Impact of erosion and transfer processes in Polycyclic Aromatic Hydrocarbon contamination of water bodies in the Seine River basin (France)

    NASA Astrophysics Data System (ADS)

    Gateuille, David; Evrard, Olivier; Moreau-Guigon, Elodie; Chevreuil, Marc; Mouchel, Jean-Marie

    2014-05-01

    Polycyclic Aromatic Hydrocarbons (PAHs) reach problematic concentrations in water and sediment of numerous streams of the world. In the Seine River (France), they prevent to achieve the good chemical status enforced by European law. However, the provenance and the fate of PAHs found in rivers are still poorly understood. Here, we combined chemical and fallout radionuclide measurements conducted on a large number of suspended sediment (SS) (n = 231) and soil (n = 37) samples collected at 62 sites during an entire hydrological year. A model was developed to estimate mean PAH concentration in sediment from the population density in the drainage area and good relationships were found during both low stage and flood periods. Influence of human population also appeared to be stronger during the latter period. However, some discrepancies between measured and modeled PAH concentrations were observed and the role of the origin of SS was investigated. During the low flow period, the observed differences were explained by the provenance of river sediment (agricultural topsoil vs. eroded channel banks). Time-averaged PAH concentrations measured in suspended sediment collected in the catchments where erosion of agricultural topsoil dominated were systematically higher than the predicted values. On the contrary, in the catchments where erosion mainly occurred in deep soil or river embankment, the supply of particles protected from atmospheric fallout contamination led to measure concentrations below the predicted values. As this relationship between population density and SS contamination was no longer valid during the flood period, the role of transfer times was also investigated. The percentages of freshly eroded sediment in samples were determined by comparing the 7Be/210Pb ratio in rainfall and SS. An annual turn-over cycle of sediment was observed but no relationship was found between PAH contamination and residence times of particles within rivers. This result suggested

  9. Contaminant-mobilizing capability of fullerene nanoparticles (nC60): Effect of solvent-exchange process in nC60 formation.

    PubMed

    Wang, Lilin; Fortner, John D; Hou, Lei; Zhang, Chengdong; Kan, Amy T; Tomson, Mason B; Chen, Wei

    2013-02-01

    Fullerene nanoparticles (nC(60)) in aqueous environments can significantly enhance the transport of hydrophobic organic contaminants by serving as a contaminant carrier. In the present study, the authors examine the effect of the solvent-exchange process on nC(60) aggregate formation and, subsequently, on nC(60) 's contaminant-mobilizing capability. A series of nC(60) samples were prepared using a modified toluene-water solvent-exchange method through the inclusion of a secondary organic solvent in the phase transfer of molecular C(60) in toluene to nC(60) in water. Two groups of solvents--a water-miscible group and a non-water-miscible group-of varied polarity were selected as secondary solvents. The involvement of a secondary solvent in the phase transfer process had only small effects on the particle size and distribution, ζ potential, and mobility of the nC(60) products but significantly influenced the capability of nC(60) to enhance the transport of 2,2',5,5'-polychlorinated biphenyl (PCB) in a saturated sandy soil column, regardless of whether the secondary solvent was water-miscible or non-water-miscible. The two groups of secondary solvents appear to affect the aggregation properties of nC(60) in water via different mechanisms. In general, nC(60) products made with a secondary water-miscible solvent have stronger capabilities to enhance PCB transport. Taken together, the results indicate that according to formation conditions and solvent constituents, nC(60) will vary significantly in its interactions with organic contaminants, specifically as related to adsorption or desorption as well as transport in porous media. PMID:23172734

  10. Transformation of Contaminant Candidate List (CCL3) compounds during ozonation and advanced oxidation processes in drinking water: Assessment of biological effects.

    PubMed

    Mestankova, Hana; Parker, Austa M; Bramaz, Nadine; Canonica, Silvio; Schirmer, Kristin; von Gunten, Urs; Linden, Karl G

    2016-04-15

    The removal of emerging contaminants during water treatment is a current issue and various technologies are being explored. These include UV- and ozone-based advanced oxidation processes (AOPs). In this study, AOPs were explored for their degradation capabilities of 25 chemical contaminants on the US Environmental Protection Agency's Contaminant Candidate List 3 (CCL3) in drinking water. Twenty-three of these were found to be amenable to hydroxyl radical-based treatment, with second-order rate constants for their reactions with hydroxyl radicals (OH) in the range of 3-8 × 10(9) M(-1) s(-1). The development of biological activity of the contaminants, focusing on mutagenicity and estrogenicity, was followed in parallel with their degradation using the Ames and YES bioassays to detect potential changes in biological effects during oxidative treatment. The majority of treatment cases resulted in a loss of biological activity upon oxidation of the parent compounds without generation of any form of estrogenicity or mutagenicity. However, an increase in mutagenic activity was detected by oxidative transformation of the following CCL3 parent compounds: nitrobenzene (OH, UV photolysis), quinoline (OH, ozone), methamidophos (OH), N-nitrosopyrolidine (OH), N-nitrosodi-n-propylamine (OH), aniline (UV photolysis), and N-nitrosodiphenylamine (UV photolysis). Only one case of formation of estrogenic activity was observed, namely, for the oxidation of quinoline by OH. Overall, this study provides fundamental and practical information on AOP-based treatment of specific compounds of concern and represents a framework for evaluating the performance of transformation-based treatment processes. PMID:26900972

  11. Test Results From a Pair of 1-kWe Dual-Opposed Free-Piston Stirling Power Convertors Integrated With a Pumped NaK Loop

    NASA Technical Reports Server (NTRS)

    Geng, Steven M.; Briggs, Maxwell H.; Penswick, L. Barry; Pearson, J. Boise; Godfroy, Thomas J.

    2011-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1-kW-class free-piston Stirling convertors were modified to operate with a NaK (sodium (Na) and potassium (K)) liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The convertors were successfully tested at the Marshall Space Flight Center (MSFC) from June 6 through July 14, 2009. The convertors were operated for a total test time of 66 hr and 16 min. The tests included (a) performance mapping the convertors over various hot- and cold-end temperatures, piston amplitudes, and NaK flow rates and (b) transient test conditions to simulate various startup (i.e., low-, medium-, and high-temperature startups) and fault scenarios (i.e., loss of heat source, loss of NaK pump, convertor stall, etc.). This report documents the results of this testing

  12. Summary of Test Results From a 1 kW(sub e)-Class Free-Piston Stirling Power Convertor Integrated With a Pumped NaK Loop

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.; Geng, Steven M.; Pearson, J. Boise; Godfroy, Thomas J.

    2010-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors was modified to operate with a NaK liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The tests included performance mapping the convertors over various hot and cold-end temperatures, piston amplitudes and NaK flow rates; and transient test conditions to simulate various start-up and fault scenarios. Performance maps of the convertors generated using the pumped NaK loop for thermal input show increases in power output over those measured during baseline testing using electric heating. Transient testing showed that the Stirling convertors can be successfully started in a variety of different scenarios and that the convertors can recover from a variety of fault scenarios.

  13. Summary of Test Results From a 1 kWe-Class Free-Piston Stirling Power Convertor Integrated With a Pumped NaK Loop

    NASA Technical Reports Server (NTRS)

    Briggs, Maxwell H.; Geng, Steven M.; Pearson, J. Boise; Godfroy, Thomas J.

    2010-01-01

    As a step towards development of Stirling power conversion for potential use in Fission Surface Power (FSP) systems, a pair of commercially available 1 kW class free-piston Stirling convertors was modified to operate with a NaK liquid metal pumped loop for thermal energy input. This was the first-ever attempt at powering a free-piston Stirling engine with a pumped liquid metal heat source and is a major FSP project milestone towards demonstrating technical feasibility. The tests included performance mapping the convertors over various hot and cold-end temperatures, piston amplitudes and NaK flow rates; and transient test conditions to simulate various start-up and fault scenarios. Performance maps of the convertors generated using the pumped NaK loop for thermal input show increases in power output over those measured during baseline testing using electric heating. Transient testing showed that the Stirling convertors can be successfully started in a variety of different scenarios and that the convertors can recover from a variety of fault scenarios.

  14. Stepwise evolution of resistance to toxic cardenolides via genetic substitutions in the Na+/K+ -ATPase of milkweed butterflies (lepidoptera: Danaini).

    PubMed

    Petschenka, Georg; Fandrich, Steffi; Sander, Nils; Wagschal, Vera; Boppré, Michael; Dobler, Susanne

    2013-09-01

    Despite the monarch butterfly (Danaus plexippus) being famous for its adaptations to the defensive traits of its milkweed host plants, little is known about the macroevolution of these traits. Unlike most other animal species, monarchs are largely insensitive to cardenolides, because their target site, the sodium pump (Na(+)/K(+) -ATPase), has evolved amino acid substitutions that reduce cardenolide binding (so-called target site insensitivity, TSI). Because many, but not all, species of milkweed butterflies (Danaini) are associated with cardenolide-containing host plants, we analyzed 16 species, representing all phylogenetic lineages of milkweed butterflies, for the occurrence of TSI by sequence analyses of the Na(+)/K(+) -ATPase gene and by enzymatic assays with extracted Na(+)/K(+) -ATPase. Here we report that sensitivity to cardenolides was reduced in a stepwise manner during the macroevolution of milkweed butterflies. Strikingly, not all Danaini typically consuming cardenolides showed TSI, but rather TSI was more strongly associated with sequestration of toxic cardenolides. Thus, the interplay between bottom-up selection by plant compounds and top-down selection by natural enemies can explain the evolutionary sequence of adaptations to these toxins. PMID:24033181

  15. Contaminated water treatment

    NASA Technical Reports Server (NTRS)

    Gormly, Sherwin J. (Inventor); Flynn, Michael T. (Inventor)

    2010-01-01

    Method and system for processing of a liquid ("contaminant liquid") containing water and containing urine and/or other contaminants in a two step process. Urine, or a contaminated liquid similar to and/or containing urine and thus having a relatively high salt and urea content is passed through an activated carbon filter to provide a resulting liquid, to remove most of the organic molecules. The resulting liquid is passed through a semipermeable membrane from a membrane first side to a membrane second side, where a fortified drink having a lower water concentration (higher osmotic potential) than the resulting liquid is positioned. Osmotic pressure differential causes the water, but not most of the remaining inorganic (salts) contaminant(s) to pass through the membrane to the fortified drink. Optionally, the resulting liquid is allowed to precipitate additional organic molecules before passage through the membrane.

  16. Quantitative assessment of the Salmonella distribution on fresh-cut leafy vegetables due to cross-contamination occurred in an industrial process simulated at laboratory scale.

    PubMed

    Pérez-Rodríguez, Fernando; Saiz-Abajo, M José; Garcia-Gimeno, R M; Moreno, Ana; González, David; Vitas, Ana Isabel

    2014-08-01

    Fecal pathogen distributions in fresh-cut leafy vegetables are essential to develop suitable sampling plans so as to detect pathogen contaminations. In this study, a typical fresh-cut lettuce process was reproduced at pilot scale with different initial inoculum levels of Salmonella on lettuce (6-7, 4 and 1 log CFU/g). The pathogen was determined in all processed lettuce samples (n ≥ 50) and obtained count data were used to fit different probability distributions. The study showed that Salmonella is homogenously distributed on fresh-cut leafy vegetables as a result of processing (mainly washing) at all contamination levels. Negative binomial and Poisson-lognormal distributions were suitable to describe pathogen distribution at the high and medium levels. coefficient of variation modified (CV) indicated no overdispersion (i.e. clustering). Nevertheless, further research will be needed to assess the effect of using disinfectants in washing water on the final distribution pattern of pathogens in processed fresh-cut leafy vegetables. PMID:24943007

  17. Activation of the biochemical processes in an oil-contaminated soil using a light-correcting film and humic acids

    NASA Astrophysics Data System (ADS)

    Filatov, D. A.; Ivanov, A. A.; Svarovskaya, L. I.; Yudina, N. V.

    2011-02-01

    It was shown that the use of a light-correcting film as a covering material for an oil-contaminated soil in combination with humic acids increased the number of the main physiological groups of the soil microorganisms responsible for the development of the soil's fertility (heterotrophic bacteria, actinomycetes, and micromycetes) by 60-100 times. The activity of the soil enzymes (catalase, dehydrogenase, polyphenoloxidase, peroxidase, and urease) increased by 3-6 times. The biochemical oxidation of oil hydrocarbons in the soil became significantly more intense.

  18. Effect of the ultrasound-Fenton oxidation process with the addition of a chelating agent on the removal of petroleum-based contaminants from soil.

    PubMed

    Li, Ying; Li, Fangmin; Li, Fanxiu; Yuan, Fuqian; Wei, Pingfang

    2015-12-01

    The effects of ultrasonic irradiation, the chelating agent modified Fenton reaction, and a combination of ultrasound and the Fenton method in removing petroleum contaminants from a soil were studied. The results showed that the contaminant removal rate of the Fenton treatment combined with an oxalic acid chelating agent was 55.6% higher than that without a chelating agent. The average removal rate of the contaminants using the ultrasound-Fenton treatment was 59.0% higher than that without ultrasonic treatment. A combination of ultrasound and an Fe(2+)/Fe(3+)-oxalate complex-modified Fenton reagent resulted in significantly higher removal rates of n-alkanes (C(n)H(2n+2), n < 28), isoprenoid hydrocarbons, aromatic hydrocarbons, and saturated polycyclic terpenes compared with the ultrasound treatment alone or the Fenton method. The Fenton reaction and the ultrasound-Fenton treatment can unselectively remove multiple components of residual hydrocarbons and a number of benzene rings in polycyclic aromatic hydrocarbons. The chemistry of the heterocyclic compounds and the position and number of substituents can affect the degradation process. PMID:26268625

  19. Test and application of a general process-based dynamic coastal mass-balance model for contaminants using data for radionuclides in the Dnieper-Bug estuary.

    PubMed

    Håkanson, Lars; Lindgren, Dan

    2009-01-01

    In this work a general, process-based mass-balance model for water contaminants for coastal areas at the ecosystem scale (CoastMab) is presented and for the first time tested for radionuclides. The model is dynamic, based on ordinary differential equations and gives monthly predictions. Connected to the core model there is also a sub-model for contaminant concentrations in fish. CoastMab calculates sedimentation, resuspension, diffusion, mixing, burial and retention of the given contaminant. The model contains both general algorithms, which apply to all contaminants, and substance-specific parts (such as algorithms for the particulate fraction, diffusion, biouptake and biological half-life). CoastMab and the sub-model for fish are simple to apply in practice since all driving variables may be readily accessed from maps or regular monitoring programs. The separation between the surface-water layer and the deep-water layer is not done as in most traditional models from water temperature data but from sedimentological criteria. Previous versions of the models for phosphorus and suspended particulate matter (in the Baltic Sea) have been validated and shown to predict well. This work presents modifications of the model and tests using two tracers, radiocesium and radiostrontium (from the Chernobyl fallout) in the Dnieper-Bug estuary (the Black Sea). Good correlations are shown between modeled and empirical data, except for the month directly after the fallout. We have, e.g., shown that: 1. The conditions in the sea outside the bay are important for the concentrations of the substances in water, sediments and fish within the bay, 2. We have demonstrated "biological," "chemical" and "water" dilution, 3. That the water chemical conditions in the bay influence biouptake and concentrations in fish of the radionuclides and 4. That the feeding behaviour of the coastal fish is very important for the biouptake of the radionuclides. PMID:19004470

  20. Use of Bacillus thuringiensis supernatant from a fermentation process to improve bioremediation of chlorpyrifos in contaminated soils.

    PubMed

    Aceves-Diez, Angel E; Estrada-Castañeda, Kelly J; Castañeda-Sandoval, Laura M

    2015-07-01

    The aim of this research was to investigate the potential of a nutrient-rich organic waste, namely the cell-free supernatant of Bacillus thuringiensis (BtS) gathered from fermentation, as a biostimulating agent to improve and sustain microbial populations and their enzymatic activities, thereby assisting in the bioremediation of chlorpyrifos-contaminated soil at a high dose (70 mg kg(-1)). Experiments were performed for up to 80 d. Chlorpyrifos degradation and its major metabolic product, 3,5,6-trichloro-2-pyridinol (TCP), were quantified by high-performance liquid chromatography (HPLC); total microbial populations were enumerated by direct counts in specific medium; and fluorescein diacetate (FDA) hydrolysis was measured as an index of soil microbial activity. Throughout the experiment, there was higher chlorpyrifos degradation in soil supplemented with BtS (83.1%) as compared to non-supplemented soil. TCP formation and degradation occurred in all soils, but the greatest degradation (30.34%) was observed in soil supplemented with BtS. The total microbial populations were significantly improved by supplementation with BtS. The application of chlorpyrifos to soil inhibited the enzymatic activity; however, this negative effect was counteracted by BtS, inducing an increase of approximately 16% in FDA hydrolysis. These results demonstrate the potential of B. thuringiensis supernatant as a suitable biostimulation agent for enhancing chlorpyrifos and TCP biodegradation in chlorpyrifos-contaminated soils. PMID:25910975

  1. Microbial Community Dynamics during the Bioremediation Process of Chlorimuron-Ethyl-Contaminated Soil by Hansschlegelia sp. Strain CHL1

    PubMed Central

    Yang, Liqiang; Li, Xinyu; Li, Xu; Su, Zhencheng; Zhang, Chenggang; Zhang, Huiwen

    2015-01-01

    Long-term and excessive application of chlorimuron-ethyl has led to a series of environmental problems. Strain Hansschlegelia sp. CHL1, a highly efficient chlorimuron-ethyl degrading bacterium isolated in our previous study, was employed in the current soil bioremediation study. The residues of chlorimuron-ethyl in soils were detected, and the changes of soil microbial communities were investigated by phospholipid fatty acid (PLFA) analysis. The results showed that strain CHL1 exhibited significant chlorimuron-ethyl degradation ability at wide range of concentrations between 10μg kg-1 and 1000μg kg-1. High concentrations of chlorimuron-ethyl significantly decreased the total concentration of PLFAs and the Shannon-Wiener indices and increased the stress level of microbes in soils. The inoculation with strain CHL1, however, reduced the inhibition on soil microbes caused by chlorimuron-ethyl. The results demonstrated that strain CHL1 is effective in the remediation of chlorimuron-ethyl-contaminated soil, and has the potential to remediate chlorimuron-ethyl contaminated soils in situ. PMID:25689050

  2. Alternative biological-treatment processes for remediation of creosote- and PCP-contaminated materials: Bench-scale treatability studies

    SciTech Connect

    Mueller, J.G.; Lantz, S.E.; Blattman, B.O.; Middaugh, D.P.; Chapman, P.J.

    1991-03-01

    Bench-scale biotreatability studies were performed to determine the most effective of two bioremediation application strategies to ameliorate creosote- and pentachlorophenol (PCP)-contaminated soils present at the American Creosote Works Superfund site, Pensacola, Florida: solid-phase bioremediation or slurry-phase bioremediation. When indigenous microorganisms were employed as biocatalysts, solid-phase bioremediation was slow and ineffective (8-12 weeks required to biodegrade >50% of resident organics). Biodegradation was limited to lower-molecular-weight constituents rather than the more hazardous, higher-molecular-weight (HMW) compounds; PCP and HMW polycyclic aromatic hydrocarbons (PAHs) containing 4 or more fused rings resisted biological attach. Moreover, supplementation with aqueous solution of inorganic nutrients had little effect on the overall effectiveness of the treatment strategy. Alternatively, slurry-phase bioremediation was much more effective: >50% of targeted organics were biodegraded in 14 days. Again, however, more persistent contaminants, such as PCP and HMW PAHs, were not extensively degraded when subjected to the action of indigenous microorganisms.

  3. Removal of heavy metals and arsenic from a co-contaminated soil by sieving combined with washing process.

    PubMed

    Liao, Xiaoyong; Li, You; Yan, Xiulan

    2016-03-01

    Batch experiments were conducted with a heavy metals and arsenic co-contaminated soil from an abandoned mine to evaluate the feasibility of a remediation technology that combines sieving with soil washing. Leaching of the arsenic and heavy metals from the different particle size fractions was found to decrease in the order: <0.1, 2-0.1, and >2mm. With increased contact time, the concentration of heavy metals in the leachate was significantly decreased for small particles, probably because of adsorption by the clay soil component. For the different particle sizes, the removal efficiencies for Pb and Cd were 75%-87%, and 61%-77% for Zn and Cu, although the extent of removal was decreased for As and Cr at <45%. The highest efficiency by washing for Pb, Cd, Zn, and As was from the soil particles >2mm, although good metal removal efficiencies were also achieved in the small particle size fractions. Through SEM-EDS observations and correlation analysis, the leaching regularity of the heavy metals and arsenic was found to be closely related to Fe, Mn, and Ca contents of the soil fractions. The remediation of heavy metal-contaminated soil by sieving combined with soil washing was proven to be efficient, and practical remediation parameters were also recommended. PMID:26969066

  4. Polycyclic aromatic hydrocarbon-contaminated soils: bioaugmentation of autochthonous bacteria and toxicological assessment of the bioremediation process by means of Vicia faba L.

    PubMed

    Ruffini Castiglione, Monica; Giorgetti, Lucia; Becarelli, Simone; Siracusa, Giovanna; Lorenzi, Roberto; Di Gregorio, Simona

    2016-04-01

    Two bacterial strains, Achromobacter sp. (ACH01) and Sphingomonas sp. (SPH01), were isolated from a heavily polycyclic aromatic hydrocarbon (PAH)-contaminated soil (5431.3 ± 102.3 ppm) for their capacity to use a mixture of anthracene, pyrene, phenanthrene and fluorene as sole carbon sources for growth and for the capacity to produce biosurfactants. The two strains were exploited for bioaugmentation in a biopile pilot plant to increase the bioavailability and the degradation of the residual PAH contamination (99.5 ± 7.1 ppm) reached after 9 months of treatment. The denaturing gel gradient electrophoresis (DGGE) profile of the microbial ecology of the soil during the experimentation showed that the bioaugmentation approach was successful in terms of permanence of the two strains in the soil in treatment. The bioaugmentation of the two bacterial isolates positively correlated with the PAH depletion that reached 7.9 ± 2 ppm value in 2 months of treatment. The PAH depletion was assessed by the loss of the phyto-genotoxicity of soil elutriates on the model plant Vicia faba L., toxicological assessment adopted also to determine the minimum length of the decontamination process for obtaining both the depletion of the PAH contamination and the detoxification of the soil at the end of the process. The intermediate phases of the bioremediation process were the most significant in terms of toxicity, inducing genotoxic effects and selective DNA fragmentation in the stem cell niche of the root tip. The selective DNA fragmentation can be related to the selective induction of cell death of mutant stem cells that can compromise offsprings. PMID:26769476

  5. Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

    SciTech Connect

    Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

    2005-02-06

    Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.

  6. Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

    NASA Astrophysics Data System (ADS)

    Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

    2005-02-01

    Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.

  7. Guidelines for collecting and processing samples of stream bed sediment for analysis of trace elements and organic contaminants for the National Water-Quality Assessment Program

    USGS Publications Warehouse

    Shelton, Larry R.; Capel, Paul D.

    1994-01-01

    A major component of the U.S. Geological Survey's National Water-Quality Assessment program is to assess the occurrence and distribution of trace elements and organic contaminants in streams. The first phase of the strategy for the assessment is to analyze samples of bed sediments from depositional zones. Fine-grained particles deposited in these zones are natural accumulators of trace elements and hydrophobic organic compounds. For the information to be comparable among studies in many different parts of the Nation, strategies for selecting stream sites and depositional zones are critical. Fine-grained surficial sediments are obtained from several depositional zones within a stream reach and composited to yield a sample representing average conditions. Sample collection and processing must be done consistently and by procedures specifically designed to separate the fine material into fractions that yield uncontaminated samples for trace-level analytes in the laboratory. Special coring samplers and other instruments made of Teflon are used for collection. Samples are processed through a 2.0-millimeter stainless-steel mesh sieve for organic contaminate analysis and a 63-micrometer nylon-cloth sieve for trace-element analysis. Quality assurance is maintained by strict collection and processing procedures, duplicate samplings, and a rigid cleaning procedure.

  8. A process of applying polypyrrole-engineered pulp fibers prepared using hydrogen peroxide as oxidant to detoxification of Cr(VI)-contaminated water.

    PubMed

    Lei, Yu; Qian, Xueren; Shen, Jing; An, Xianhui

    2013-03-01

    In this study, different from previous reports, an alternative process for detoxification of Cr(VI)-contaminated water with polypyrrole-engineered pulp fibers prepared using low cost hydrogen peroxide as oxidant was proposed. The process conditions in preparation of the engineered fibers as well as the water treatment conditions were optimized, and the behavior of Cr desorption from the engineered fibers was evaluated. The results showed that the proposed process was highly efficient in Cr(VI)-detoxification via the integration of adsorption with reduction. Compared with the previously reported polyaniline-engineered fibers prepared with hydrogen peroxide as oxidant, the engineered fibers studied in this work was much more effective. PMID:23340110

  9. Effective use of risk assessments and the public comment process to achieve acceptable remediation goals for mercury-contaminated sites

    SciTech Connect

    Miller, J.Q.; Barnett, M.

    1996-04-01

    As a result of recalculating risk levels using new information, the remediation goals and cleanup strategy for the Lower East Fork Poplar Creek floodplains have been significantly changed to reflect an important reduction in cleanup costs while ensuring protectionof human health and the environment. This project and its stakeholders have made the risk assessment more effective by better defining the contaminant and adjusting assessment parameters. As a result, the remediation goal initially set at 50 ppM Hg has been changed to 400 ppM, resulting in significant reductions in both the destruction of the floodplain landscape and project costs. Volume of soils to be excavated has been decreased from 1 million cubic yards to 25,000 cubic yards, and the cost has been reduced from about $1 billion to less than $20 million. The Record of Decision for Lower East Fork Poplar Creek was approved in August 1995.

  10. Assessment and control of water contamination associated with shale oil extraction and processing. Progress report, October 1, 1979-September 30, 1980

    SciTech Connect

    Peterson, E.J.; Henicksman, A.V.; Fox, J.P.; O'Rourke, J.A.; Wagner, P.

    1982-04-01

    The Los Alamos National Laboratory's research on assessment and control of water contamination associated with oil shale operations is directed toward the identification of potential water contamination problems and the evaluation of alternative control strategies for controlling contaminants released into the surface and underground water systems from oil-shale-related sources. Laboratory assessment activities have focused on the mineralogy, trace element concentrations in solids, and leaching characteristics of raw and spent shales from field operations and laboratory-generated spent shales. This report details the chemical, mineralogic, and solution behavior of major, minor, and trace elements in a variety of shale materials (spent shales from Occidental retort 3E at Logan Wash, raw shale from the Colony mine, and laboratory heat-treated shales generated from Colony mine raw shale). Control technology research activities have focused on the definition of control technology requirements based on assessment activities and the laboratory evaluation of alternative control strategies for mitigation of identified problems. Based on results obtained with Logan Wash materials, it appears that the overall impact of in situ processing on groundwater quality (leaching and aquifer bridging) may be less significant than previously believed. Most elements leached from MIS spent shales are already elevated in most groundwaters. Analysis indicates that solubility controls by major cations and anions will aid in mitigating water quality impacts. The exceptions include the trace elements vanadium, lead, and selenium. With respect to in situ retort leaching, process control and multistaged counterflow leaching are evaluated as alternative control strategies for mitigation of quality impacts. The results of these analyses are presented in this report.

  11. Remediation of PAH-contaminated soil at a gas manufacturing plant by a combined two-phase partition system washing and microbial degradation process.

    PubMed

    Gong, Xuan; Xu, Xinyang; Gong, Zongqiang; Li, Xiaojun; Jia, Chunyun; Guo, Meixia; Li, Haibo

    2015-08-01

    The aim of this study was to design a remediation technique using both soil washing and microbial degradation to remove polycyclic aromatic hydrocarbons (PAHs) from contaminated soil. PAH biodegradation by inoculation of Mycobacterium sp. was first tested. The effectiveness of washing agents (Tween 80 solution, biodiesel, and a two-phase partition system (TPPS)) was then evaluated with column experiments. Third, the combination of TPPS washing and microbial degradation was studied. PAH bioavailability before and after biodegradation and the joint remediation was also assessed using hydroxypropyl-β-cyclodextrin (HPCD) extraction. Only phenanthrene and anthracene were noticeably biodegradable when the soil was inoculated with Mycobacterium sp. TPPS containing 2% (v/v) biodiesel and 2.5% (w/v) Tween 80 was used as the washing agent for the joint remediation test because it gave higher PAH extractions than Tween 80 solution with lower doses, and there was less residue in the soil. Joint TPPS washing and microbial degradation gave a total PAH removal of 92.6%, which was much higher than the results from either the biodegradation or washing experiments alone. Removals of all high molecular weight (HMW) PAHs were improved. Bioavailable concentrations of all PAHs decreased significantly after the joint remediation process, indicating that there were reduced risks from all PAHs. The results demonstrate that the combination of TPPS washing and microbial degradation is a useful and innovative process for remediation of PAH-contaminated soils. PMID:25874432

  12. Mercury Contamination - Amalgamate (contract with NFS and ADA). Demonstration of DeHgSM Process. Mixed Waste Focus Area. OST Reference Number 1675

    SciTech Connect

    None, None

    1999-09-01

    Through efforts led by the Mixed Waste Focus Area (MWFA) and its Mercury Working Group (HgWG), the inventory of bulk elemental mercury contaminated with radionuclides stored at various U.S. Department of Energy (DOE) sites is thought to be approximately 16 m3 (Conley et al. 1998). At least 19 different DOE sites have this type of mixed low-level waste in their storage facilities. The U.S. Environmental Protection Agency (EPA) specifies amalgamation as the treatment method for radioactively contaminated elemental mercury. Although the chemistry of amalgamation is well known, the practical engineering of a sizable amalgamation process has not been tested (Tyson 1993). To eliminate the existing DOE inventory in a reasonable timeframe, scalable equipment is needed that can produce waste forms that meet the EPA definition of amalgamation, produce waste forms that pass the EPA Toxicity Characteristic Leaching Procedure (TCLP) limit of 0.20 mg/L, limit mercury vapor concentrations during processing to below the Occupational Safety and Health Administration’s (OSHA) 8-h worker exposure limit (50 mg/m3) for mercury, and perform the above economically.

  13. Complete reduction of highly concentrated contaminants in piggery waste by a novel process scheme with an algal-bacterial symbiotic photobioreactor.

    PubMed

    Lee, Young-Shin; Han, Gee-Bong

    2016-07-15

    The complete reduction of highly concentrated contaminants in piggery waste was achieved with an innovative process scheme consecutively combining autothermal thermophilic aerobic digestion (ATAD), an expanded granular sludge bed (EGSB) and a microalgal-bacterial symbiotic vertical photobioreactor (VPBR), followed by biomass recycling for effluent polishing. Contaminants in piggery waste, such as high organic and inorganic matter, total nitrogen (TN), and total phosphorus (TP) contents, were successfully reduced in the newly implemented system. The concentrations of volatile solids (VS) and the chemical oxygen demand (COD) for organic matter in the feed were reduced by approximately 99.3% and 99.7%, respectively, in the innovative system. The overall reduction efficiencies in TN, ammoniacal nitrogen, and TP were 98.8, 98.4, and 93.5%, respectively, through ammonia gas emission, coagulated sludge disposal, and the algal-bacterial symbiotic polishing process. Fecal coliform density was decreased to <1.7 × 10(4) CFU g(-1) total solids. Biogas and CH4 in the EGSB were generated in the range of 0.36-0.79 and 0.18-0.44 L g(-1) [VS removed], respectively, and contained 245 ± 19 ppm (v/v) [H2S]. PMID:27100332

  14. Effect of variable Na/K ratio on CO2 solubility in slab-derived rhyolitic melts - An experimental study

    NASA Astrophysics Data System (ADS)

    Muth, M.; Duncan, M. S.; Dasgupta, R.

    2014-12-01

    Subduction zones are an important part of global carbon cycling and understanding the agent through which carbon is transported from the slab to the mantle wedge is key. Previous work has constrained the role of P, T, and melt-H2O content on CO2 solubility in a model, slab-derived rhyolitic partial melt [1, 2]. However, the effect of composition, i.e., the variation in cation ratios on CO2 solubility remains unknown. In particular, variation in Na/K, which can be highly variable in rhyolitic melts, can have a large effect on CO2 solubility [3, 4]. Here we investigate the effect of variable alkali ratio on the CO2 solubility in rhyolitic melt at sub-arc depths. CO2-saturated experiments were conducted at 3 GPa, 1300 °C on 3 rhyolite compositions, similar to low-degree partial melt of pelitic sediments, with fixed total alkalis (Na2O + K2O ~11.5 wt.%, volatile-free), but molar Na# = Na/(Na+K) varying from 0.15 to 0.88. Experimental run products show glasses with void spaces, suggesting the presence of CO2-rich fluid during experiments. The glasses were analyzed using EPMA and FTIR spectroscopy. All glasses show peaks for H2O at ~3540 cm-1. CO2 is dissolved as molecular CO2 (CO2mol.) at ~2350 cm-1 and carbonate (CO32-). Peaks for CO32- shift in position and shape: high Na# glass peaks are asymmetrical and closely spaced at ~1504 cm-1 and 1439 cm-1, while low Na# glass peaks are symmetrical and separated at ~1425 cm-1 and ~1530 cm-1. Our data show a strong positive correlation between Na# and CO2tot. contents from 1.0 wt.% for Na# = 0.15 to 3.0 wt.% for Na# = 0.88, at a fixed melt NBO/T ≈ 0.07. CO2mol./CO2tot. decreases with increasing Na#, from 0.74 to 0.09. These data suggest that Na has a larger effect than K on carbonate dissolution in rhyolitic melts. This is in agreement with the low P experiments on phonotephrite compositions [3], but in contrast with the observation for synthetic nephelinitic compositions [4], possibly indicating the effect of Na/K on CO2

  15. Understanding Mechanisms of Radiological Contamination

    SciTech Connect

    Rick Demmer; John Drake; Ryan James, PhD

    2014-03-01

    Over the last 50 years, the study of radiological contamination and decontamination has expanded significantly. This paper addresses the mechanisms of radiological contamination that have been reported and then discusses which methods have recently been used during performance testing of several different decontamination technologies. About twenty years ago the Idaho Nuclear Technology Engineering Center (INTEC) at the INL began a search for decontamination processes which could minimize secondary waste. In order to test the effectiveness of these decontamination technologies, a new simulated contamination, termed SIMCON, was developed. SIMCON was designed to replicate the types of contamination found on stainless steel, spent fuel processing equipment. Ten years later, the INL began research into methods for simulating urban contamination resulting from a radiological dispersal device (RDD). This work was sponsored by the Defense Advanced Research Projects Agency (DARPA) and included the initial development an aqueous application of contaminant to substrate. Since 2007, research sponsored by the US Environmental Protection Agency (EPA) has advanced that effort and led to the development of a contamination method that simulates particulate fallout from an Improvised Nuclear Device (IND). The IND method diverges from previous efforts to create tenacious contamination by simulating a reproducible “loose” contamination. Examining these different types of contamination (and subsequent decontamination processes), which have included several different radionuclides and substrates, sheds light on contamination processes that occur throughout the nuclear industry and in the urban environment.

  16. Species-dependent adaptation of the cardiac Na+/K+ pump kinetics to the intracellular Na+ concentration

    PubMed Central

    Lewalle, Alexandre; Niederer, Steven A; Smith, Nicolas P

    2014-01-01

    The Na+/K+ ATPase (NKA) plays a critical role in maintaining ionic homeostasis and dynamic function in cardiac myocytes, within both the in vivo cell and in silico models. Physiological conditions differ significantly between mammalian species. However, most existing formulations of NKA used to simulate cardiac function in computational models are derived from a broad range of experimental sources spanning many animal species. The resultant inability of these models to discern species-specific features is a significant obstacle to achieving a detailed quantitative and comparative understanding of physiological behaviour in different biological contexts. Here we present a framework for characterising the steady-state NKA current using a biophysical mechanistic model specifically designed to provide a mechanistic explanation of the NKA flux supported by self-consistent species-specific data. We thus compared NKA kinetics specific to guinea- pig and rat ventricular myocytes. We observe that the apparent binding affinity for sodium in the rat is significantly lower, whereas the overall pump cycle rate is doubled, in comparison to the guinea pig. This sensitivity of NKA to its regulatory substrates compensates for the differences in Na+ concentrations between the cell types. NKA is thereby maintained within its dynamic range over a wide range of pacing frequencies in these two species, despite significant disparities in sodium concentration. Hence, by replacing a conventional generic NKA model with our rat-specific NKA formula into a whole-cell simulation, we have, for the first time, been able to accurately reproduce the action potential duration and the steady-state sodium concentration as functions of pacing frequency. PMID:25362154

  17. NaK pool-boiler bench-scale receiver durability test: Test design and initial results

    SciTech Connect

    Andraka, C.E.; Jones, S.A.; Moreno, J.B.; Moss, T.A.

    1993-06-01

    Pool-boiler reflux receivers have been considered as an alternative to heat pipes for the input of concentrated solar energy to Stirling-cycle engines in dish-Stirling electric generation systems. Fool boilers offer simplicity in desip and fabrication. Pool-boiler solar receiver operation has been demonstrated for short periods of time. However, in order to generate cost-effective electricity, the receiver must operate without significant maintenance for the entire system life. At least one theory explaining incipient-boiling behavior of alkali metals indicates that favorable start-up behavior should deteriorate over time. Many factors affect the stability and startup behavior of the boiling system. Therefore, it is necessary to simulate the full-scale design in every detail as much as possible, including flux levels materials, and operating cycles. On-sun testing is impractical due to the limited test time available. No boiling system has been demonstrated with the current porous boiling enhancement surface and materials for a significant period of time. A test vessel was constructed with a Friction Coatings Inc. porous boiling enhancement surface. The vessel is heated with a quartz lamp array providing about 92 W/Cm{sup 2} peak incident thermal flux. The vessel is charged with NaK-78, which is liquid at room temperature. This allows the elimination of costly electric preheating, both on this test and on full-scale receivers. The vessel is fabricated from Haynes 230 alloy, selected for its high temperature strength and oxidation resistance. The vessel operates at 750{degrees}C around the clock, with a 1/2-hour shutdown cycle to ambient every 8 hours. Temperature data is continually collected. The test design and initial (first 2500 hours and 300 start-ups) test data are presented here. The test is designed to operate for 10,000 hours, and will be complete in the spring of 1994.

  18. NaK pool-boiler bench-scale receiver durability test: Test design and initial results

    SciTech Connect

    Andraka, C.E.; Jones, S.A.; Moreno, J.B.; Moss, T.A.

    1993-01-01

    Pool-boiler reflux receivers have been considered as an alternative to heat pipes for the input of concentrated solar energy to Stirling-cycle engines in dish-Stirling electric generation systems. Fool boilers offer simplicity in desip and fabrication. Pool-boiler solar receiver operation has been demonstrated for short periods of time. However, in order to generate cost-effective electricity, the receiver must operate without significant maintenance for the entire system life. At least one theory explaining incipient-boiling behavior of alkali metals indicates that favorable start-up behavior should deteriorate over time. Many factors affect the stability and startup behavior of the boiling system. Therefore, it is necessary to simulate the full-scale design in every detail as much as possible, including flux levels materials, and operating cycles. On-sun testing is impractical due to the limited test time available. No boiling system has been demonstrated with the current porous boiling enhancement surface and materials for a significant period of time. A test vessel was constructed with a Friction Coatings Inc. porous boiling enhancement surface. The vessel is heated with a quartz lamp array providing about 92 W/Cm[sup 2] peak incident thermal flux. The vessel is charged with NaK-78, which is liquid at room temperature. This allows the elimination of costly electric preheating, both on this test and on full-scale receivers. The vessel is fabricated from Haynes 230 alloy, selected for its high temperature strength and oxidation resistance. The vessel operates at 750[degrees]C around the clock, with a 1/2-hour shutdown cycle to ambient every 8 hours. Temperature data is continually collected. The test design and initial (first 2500 hours and 300 start-ups) test data are presented here. The test is designed to operate for 10,000 hours, and will be complete in the spring of 1994.

  19. Molecular beam study of the a 3Σ+ state of NaK up to the dissociation limit

    NASA Astrophysics Data System (ADS)

    Temelkov, I.; Knöckel, H.; Pashov, A.; Tiemann, E.

    2015-03-01

    We provide spectroscopic data for the a 3Σ+ state of the 23Na39K molecule. The experiment is done in an ultrasonic beam apparatus, starting from the ground state X 1Σ+and driving the population to the a 3Σ+ state, using a Λ scheme with fixed pump and scanning dump laser. The signals are observed as dips of the total fluorescence. The intermediate level is chosen to be strongly perturbed by the B 1Π/c 3Σ+ states mixing to overcome the singlet-triplet transfer prohibition. We observed highly resolved hyperfine spectra of various rovibrational levels of the a 3Σ+state from va=2 up to the highest vibrational levels for rotational quantum numbers Na=4 ,6 ,8 . By the typical experimental linewidth of 17 MHz, the vibrational dependence of the hyperfine splitting is clearly revealed for NaK. The absolute frequency measurements of the vibrational levels are used for improvement of the a 3Σ+ potential curve and of the derived scattering length of all natural isotope combinations. Applying the Λ scheme in the reverse direction can provide a pathway for efficient transfer of ultracold 23Na39K molecules from the Na(3 s )+K(4 s ) asymptote to the lowest levels of the ground state. We show spectra that couple the absolute ground state vX=0 ,J =0 with an appropriate intermediate state for direct realization of the reverse path. The refined theoretical model of the coupled excited states of the Na(3 s )+K(4 p ) asymptote allows predictions of efficient paths for 23Na40K ; one example is calculated.

  20. Cotransport of water by the Na+-K+-2Cl(-) cotransporter NKCC1 in mammalian epithelial cells.

    PubMed

    Hamann, Steffen; Herrera-Perez, José J; Zeuthen, Thomas; Alvarez-Leefmans, Francisco J

    2010-11-01

    Water transport by the Na+-K+-2Cl(-) cotransporter (NKCC1) was studied in confluent cultures of pigmented epithelial (PE) cells from the ciliary body of the fetal human eye. Interdependence among water, Na+ and Cl(-) fluxes mediated by NKCC1 was inferred from changes in cell water volume, monitored by intracellular self-quenching of the fluorescent dye calcein. Isosmotic removal of external Cl(-) or Na+ caused a rapid efflux of water from the cells, which was inhibited by bumetanide (10 μm). When returned to the control solution there was a rapid water influx that required the simultaneous presence of external Na+ and Cl(-). The water influx could proceed uphill, against a transmembrane osmotic gradient, suggesting that energy contained in the ion fluxes can be transferred to the water flux. The influx of water induced by changes in external [Cl(-)] saturated in a sigmoidal fashion with a Km of 60 mm, while that induced by changes in external [Na+] followed first order kinetics with a Km of about 40 mm. These parameters are consistent with ion transport mediated by NKCC1. Our findings support a previous investigation, in which we showed water transport by NKCC1 to be a result of a balance between ionic and osmotic gradients. The coupling between salt and water transport in NKCC1 represents a novel aspect of cellular water homeostasis where cells can change their volume independently of the direction of an osmotic gradient across the membrane. This has relevance for both epithelial and symmetrical cells. PMID:20819947

  1. Rapid disinfection of E-Coliform contaminated water using WO3 semiconductor catalyst by laser-induced photo-catalytic process.

    PubMed

    Gondal, Mohammed A; Khalil, Amjad

    2008-04-01

    Laser-induced photo-catalysis process using WO(3) semiconductor catalyst was applied for the study of disinfection effectiveness of E-coliform-contaminated water. For this purpose, wastewater polluted with E-coliform bacteria was exposed to 355 nm UV radiations generated by third harmonic of Nd: YAG laser in special glass cell with and without WO(3) catalyst. E-Coliform quantification was performed by direct plating method to obtain the efficiency of each disinfection treatment. The dependence of disinfection process on laser irradiation energy, amount of catalyst and duration of laser irradiation was also investigated. The disinfection with WO(3) was quite efficient inactivating E-coliforms. For inactivation of E-coliforms, less than 8 minutes' laser irradiation was required, so that, the treated water complies with the microbial standards for drinking water. This study opens the possibility of application of this simple method in rural areas of developing countries using solar radiation. PMID:18324535

  2. Electrochemical processes for in-situ treatment of contaminated soils. Annual progress report, September 1996--May 1997

    SciTech Connect

    Huang, C.P.; Cha, D.; Chang, J.H.; Qiang, Z.; Sung, M.; Cheng, L.

    1997-01-01

    'Soil samples from three industrial sites at two depths ranges (2--4 feet and 8--14 feet) were received and pertinent physico-chemical properties, such as pH, specific surface area, moisture content, organic matter content, hydraulic conductivity, cation exchange capacity (CEC), pH at zero point of charge (pH{sub zpc}), particle size distribution, organic contaminants and heavy metals fractionation were analyzed. Results show that clay and silt are the major components in the soil samples, which exhibits a relatively low hydraulic conductivity of about 10{sup -7} {approximately} 10{sup -8} cm/sec. The pH value of soil samples is in the neutral range (from pH 6.1 to 7.6) and its variation with depth is insignificant. Organic matter content is another important factor which affects soil properties such as specific surface area, chemical adsorption capacity and cation exchange capacity. Results indicate that the organic matter content ranges between 0.79% and 1.81%. The effective cation exchange capacity is from 13.8 to 21.2 meq/100 g. The values of moisture content, specific surface area and pH{sub zpc} range from 10.2--16.9%, 0.4--0.9 (m{sup 2}/g) and 2.18--2.60, respectively.'

  3. [Effect of different soil types on the remediation of copper-pyrene compound contaminated soils by EK-oxidation process].

    PubMed

    Fan, Guang-Ping; Cang, Long; Zhou, Dong-Mei; Zhou, Li-Xiang

    2011-11-01

    The effect of different soil types (red soil,yellow-brown soil and black soil) on the electrokinetic (EK)-oxidation remediation of heavy metals-organic pollutant contaminated soil was studied in laboratory-scale experiments. Copper and pyrene were chosen as model pollutant, and 12% H2O2, 10% hydroxypropyl-beta-cyclodextrin and 0.01 mol x L(-1) NaNO3 solution were added into the anode and cathode cell. The applied voltage was 1 V x cm(-1). After 15 days of EK remediation, the removal rate of pyrene and copper in red soil, yellow-brown soil and black soil were 38.5%, 46.8%, 51.3% for pyrene and 85.0%, 22.6%, 24.1% for Cu, respectively. The high pH of black soil produced high electroosmotic flow and increased the exposure of oxidants and pollutants, meanwhile the low clay content was also conducive to the desorption of pyrene. The low pH and organic matter of red soil affected the chemical species distribution of Cu and increased its removal rate. It is concluded that soil pH, clay content and heavy metal speciation in soil are the dominant factors affecting the migration and removal efficiency of pollutants. PMID:22295647

  4. Manmade and natural radionuclides in north east Atlantic shelf and slope sediments: Implications for rates of sedimentary processes and for contaminant dispersion.

    PubMed

    MacKenzie, A B; Stewart, A; Cook, G T; Mitchell, L; Ellet, D J; Griffiths, C R

    2006-10-01

    Results are presented for a study of manmade and natural radionuclides in north east Atlantic continental shelf and slope sediments to the west of Scotland. The data are interpreted in the context of sediment mixing and accumulation processes and are used to establish the westward extent of contamination of the sediment system. Offshore shelf and slope sediments were found to have post-glacial sedimentation rates of the order of 1 cm ky(-1) but nearshore sediments had much higher accumulation rates of the order of 0.1 cm y(-1). Surface mixed layer depths of up to 6 cm were observed and non-local mixing affected most of the slope sediments, resulting in advective transport of surface sediment to depths of up to 10 cm. Biodiffusion coefficients for offshore shelf and slope sediments were dominantly in the range 10(-8) to 10(-9) cm2 s(-1). The study confirmed that seawater contaminated with Sellafield waste radionuclides is dominantly entrained to the east of 7 degrees W and, consistent with this, higher levels of Sellafield derived radionuclides were confined to nearshore sediments, with lower levels to the west of 7 degrees W. 238Pu/(239,240)Pu data indicated that Sellafield contributed 75-91% of the total plutonium in coastal sediment but only about 4-8% of the total in slope sediments. By analogy, it can be concluded that a similar situation will apply to other contaminants in seawater entering the north east Atlantic via the North Channel. PMID:16757016

  5. Contributions of dry and wet depositions of polychlorinated dibenzo-p-dioxins and dibenzofurans to a contaminated site resulting from a penetachlorophenol manufacturing process.

    PubMed

    Chang, Hwang J; Wang, Shizoom; Wang, Ya F; Li, Hsing W; Wang, Lin C

    2011-04-01

    The soils at a factory for manufacturing pentachlorophenol were heavily contaminated by polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In order to verify the contributions of dry and wet deposition of PCDD/Fs from the ambient air, the concentration of PCDD/Fs in ambient air and soil were measured, the partition of particle- and gas-phases of atmospheric PCDD/Fs was calculated, and the annual fluxes of total dry and wet PCDD/F depositions were modeled. Average atmospheric PCDD/F concentration was 1.24 ng Nm(-3) (or 0.0397 ng I-TEQ Nm(-3)). Moreover, over 92.8% of total PCDD/Fs were in the particle phase, and the dominant species were high chlorinated congeners. The total PCDD/F fluxes of dry and wet deposition were 119.5 ng m(-2) year(-1) (1.34 ng I-TEQ m(-2) year(-1)) and 82.0 ng m(-2) year(-1) (1.07 ng I-TEQ m(-2) year(-1)), respectively. By scenario simulation, the total fluxes of dry and wet PCDD/F depositions were 87.1 and 68.6 ng I-TEQ, respectively. However, the estimated PCDD/F contents in the contaminated soil were 839.9 μ g I-TEQ. Hence, the contributions of total depositions of atmospheric PCDD/F were only 0.02%. The results indicated that the major sources of PCDD/F for the contaminated soil could be attributed to the pentachlorophenol manufacturing process. PMID:20559715

  6. Effect of extracellular pH on presteady-state and steady-state current mediated by the Na+/K+ pump.

    PubMed

    Vasilyev, A; Khater, K; Rakowski, R F

    2004-03-15

    A ouabain sensitive inward current occurs in Xenopus oocytes in Na+ and K(+)-free solutions. Several laboratories have investigated the properties of this current and suggested that acidic extracellular pH (pHo) produces a conducting pathway through the Na+/K+ pump that is permeable to H+ and blocked by [Na+]o. An alternative suggestion is that the current is mediated by an electrogenic H(+)-ATPase. Here we investigate the effect of pHo and [Na+]o on both transient and steady-state ouabain-sensitive current. At alkaline or neutral pHo the relaxation rate of pre-steady-state current is an exponential function of voltage. Its U-shaped voltage dependence becomes apparent at acidic pHo, as predicted by a model in which protonation of the Na+/K+ pump reduces the energy barrier between the internal solution and the Na+ occluded state. The model also predicts that acidic pHo increases steady-state current leak through the pump. The apparent pK of the titratable group(s) is approximately 6, suggesting that histidine is involved in induction of the conductance pathway. 22Na efflux experiments in squid giant axon and current measurements in oocytes at acidic pHo suggest that both Na+ and H+ are permeant. The acid-induced inward current is reduced by high [Na+]o, consistent with block by Na+. A least squares analysis predicts that H+ is four orders of magnitude more permeant than Na+, and that block occurs when 3 Na+ ions occupy a low affinity binding site (K(0.5) = 130 +/- 30 m M) with a dielectric coefficient of 0.23 +/- 0.03. These data support the conclusion that the ouabain-sensitive conducting pathway is a result of passive leak of both Na+ and H+ through the Na+/K+ pump. PMID:15138746

  7. Using complex resistivity imaging to infer biogeochemical processes associated with bioremediation of a uranium-contaminated aquifer

    SciTech Connect

    Flores-Orozco, Adrian; Williams, Kenneth H.; Long, Philip E.; Hubbard, Susan S.; Kemna, Andreas

    2011-07-07

    Experiments at the Department of Energy’s Rifle Integrated Field Research Challenge (IFRC) site near Rifle, Colorado (USA) have demonstrated the ability to remove uranium from groundwater by stimulating the growth and activity of Geobacter species through acetate amendment. Prolonging the activity of these strains in order to optimize uranium bioremediation has prompted the development of minimally-invasive and spatially-extensive monitoring methods diagnostic of their in situ activity and the end products of their metabolism. Here we demonstrate the use of complex resistivity imaging for monitoring biogeochemical changes accompanying stimulation of indigenous aquifer microorganisms during and after a prolonged period (100+ days) of acetate injection. A thorough raw-data statistical analysis of discrepancies between normal and reciprocal measurements and incorporation of a new power-law phase-error model in the inversion were used to significantly improve the quality of the resistivity phase images over those obtained during previous monitoring experiments at the Rifle IRFC site. The imaging results reveal spatiotemporal changes in the phase response of aquifer sediments, which correlate with increases in Fe(II) and precipitation of metal sulfides (e.g., FeS) following the iterative stimulation of iron and sulfate reducing microorganism. Only modest changes in resistivity magnitude were observed over the monitoring period. The largest phase anomalies (>40 mrad) were observed hundreds of days after halting acetate injection, in conjunction with accumulation of Fe(II) in the presence of residual FeS minerals, reflecting preservation of geochemically reduced conditions in the aquifer – a prerequisite for ensuring the long-term stability of immobilized, redox-sensitive contaminants, such as uranium.

  8. Using complex resistivity imaging to infer biogeochemical processes associated with bioremediation of a uranium-contaminated aquifer

    SciTech Connect

    Orozco, A. Flores; Williams, K.H.; Long, P.E.; Hubbard, S.S.; Kemna, A.

    2011-04-01

    Experiments at the Department of Energy's Rifle Integrated Field Research Challenge (IFRC) site near Rifle, Colorado (USA) have demonstrated the ability to remove uranium from groundwater by stimulating the growth and activity of Geobacter species through acetate amendment. Prolonging the activity of these strains in order to optimize uranium bioremediation has prompted the development of minimally-invasive and spatially-extensive monitoring methods diagnostic of their in situ activity and the end products of their metabolism. Here we demonstrate the use of complex resistivity imaging for monitoring biogeochemical changes accompanying stimulation of indigenous aquifer microorganisms during and after a prolonged period (100+ days) of acetate injection. A thorough raw-data statistical analysis of discrepancies between normal and reciprocal measurements and incorporation of a new power-law phase-error model in the inversion were used to significantly improve the quality of the resistivity phase images over those obtained during previous monitoring experiments at the Rifle IRFC site. The imaging results reveal spatiotemporal changes in the phase response of aquifer sediments, which correlate with increases in Fe(II) and precipitation of metal sulfides (e.g., FeS) following the iterative stimulation of iron and sulfate reducing microorganism. Only modest changes in resistivity magnitude were observed over the monitoring period. The largest phase anomalies (>40 mrad) were observed hundreds of days after halting acetate injection, in conjunction with accumulation of Fe(II) in the presence of residual FeS minerals, reflecting preservation of geochemically reduced conditions in the aquifer - a prerequisite for ensuring the long-term stability of immobilized, redox-sensitive contaminants, such as uranium.

  9. Gaseous deposition contributes to the contamination of surface waters by pesticides close to treated fields. A process-based model study.

    PubMed

    Bedos, Carole; Loubet, Benjamin; Barriuso, Enrique

    2013-12-17

    The contribution of atmospheric pathways to surface waters contamination by pesticides has been demonstrated. At the local scale, modeling approaches as well as measurements show situations where the contribution of gaseous dry deposition is of the same order or even higher than the drift contribution. The approach presented here consists in estimating the gaseous emissions of pesticides applied in the field, their atmospheric dispersion, and finally their gaseous deposition into aquatic ecosystems at the local scale by running process-based models, that is, the one-dimensional model for pesticide volatilization following application on bare soil (Volt'Air) and the local-scale dispersion and deposition model (FIDES-2D), adapted for pesticides. A significant number of scenarios describes contrasted situations in terms of pedoclimatic conditions (covering 9 years of meteorological data), periods of pesticide application per year, physicochemical properties of the pesticides, and spatial configurations. The identification of the main factors governing gaseous deposition led to the definition of an effective emission factor which explains a large part of the deposition variability. Based on the model outputs, deposition curves are proposed, as a base for a new tool to assess the contribution of gaseous deposition to nontarget ecosystem contamination. PMID:24206530

  10. Monitoring of Emerging and Legacy Contaminants in Groundwater and Tap Water of the Karst Region in Northern Puerto Rico for Assessment of Sources and Fate and Transport Processes

    NASA Astrophysics Data System (ADS)

    Padilla, I. Y.; Cotto, I.; Torres, P. M.

    2014-12-01

    tap water (30%). Results indicated that most CVOCs on tap water come from groundwater sources. Spatial-temporal analysis of CVOC data shows that transport through karst system is highly heterogeneous variable, and reflect high capacity of the system to store and slowly release contaminants through rate-limited mass transport process.

  11. Method to reduce particles and defects on unprocessed wafers caused by clusterization and cross contamination from processed wafers

    NASA Astrophysics Data System (ADS)

    Sant, Sanket

    2012-10-01

    One of the leading problems in the semiconductor industry with device scaling is defects and particles. Of this the most important ones are particles that can clusterize (condensate) with exposure to atmosphere. These clusters can be formed by residual halides or halide structures on the wafer surface reacting with surface moisture which is unavoidable. Such clusters can prove detrimental to the processed wafer, but more interestingly can migrate inside the FOUP onto unetched wafers. This migration of clusters can cause micro masking and other defects when these wafers are processed. This reduces the wafer yield and is challenging to resolve as we move towards smaller nodes. In this work, different methods of eliminating cross condensation defects and avoiding cluster formation on processed wafers are discussed. UV, Ozone and heat are the primary candidates explored and the mechanism behind each method is explored and optimized. Impact of each mechanism on wafer yield, part corrosion in a reactor platform and wafer throughput has been studied.

  12. 9 CFR 381.91 - Contamination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Contamination. 381.91 Section 381.91... § 381.91 Contamination. (a) Carcasses of poultry contaminated by volatile oils, paints, poisons, gases... station away from the main processing line, by any method that will remove the contamination, such...

  13. 9 CFR 381.91 - Contamination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Contamination. 381.91 Section 381.91... § 381.91 Contamination. (a) Carcasses of poultry contaminated by volatile oils, paints, poisons, gases... station away from the main processing line, by any method that will remove the contamination, such...

  14. 9 CFR 381.91 - Contamination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Contamination. 381.91 Section 381.91... § 381.91 Contamination. (a) Carcasses of poultry contaminated by volatile oils, paints, poisons, gases... station away from the main processing line, by any method that will remove the contamination, such...

  15. 9 CFR 381.91 - Contamination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Contamination. 381.91 Section 381.91... § 381.91 Contamination. (a) Carcasses of poultry contaminated by volatile oils, paints, poisons, gases... station away from the main processing line, by any method that will remove the contamination, such...

  16. 9 CFR 381.91 - Contamination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Contamination. 381.91 Section 381.91... § 381.91 Contamination. (a) Carcasses of poultry contaminated by volatile oils, paints, poisons, gases... station away from the main processing line, by any method that will remove the contamination, such...

  17. Process for recovering uranium from waste hydrocarbon oils containing the same. [Uranium contaminated lubricating oils from gaseous diffusion compressors

    DOEpatents

    Conrad, M.C.; Getz, P.A.; Hickman, J.E.; Payne, L.D.

    1982-06-29

    The invention is a process for the recovery of uranium from uranium-bearing hydrocarbon oils containing carboxylic acid as a degradation product. In one aspect, the invention comprises providing an emulsion of water and the oil, heating the same to a temperature effecting conversion of the emulsion to an organic phase and to an acidic aqueous phase containing uranium carboxylate, and recovering the uranium from the aqueous phase. The process is effective, simple and comparatively inexpensive. It avoids the use of toxic reagents and the formation of undesirable intermediates.

  18. ADVANCED OXIDATION PROCESSES (AOPS) FOR DESTRUCTION OF METHYL TERTIARY BUTYL ETHER (MTBE -AN UNREGULATED CONTAMINANT) IN DRINKING WATER

    EPA Science Inventory

    Advanced oxidation processes (AOPs) provide a promising treatment option for the destruction of MTBE directly in surface and ground waters. An ongoing study is evaluating the ability of three AOPs; hydrogen peroxide/ozone (H2O2/ O3), ultraviolet irradiation/ozone (UV/O3) and ultr...

  19. ORGANIC CONTAMINANTS

    EPA Science Inventory

    Organic pollutants may constitute the most widespread waste loadings into the waters of Lake Superior. There are essentially three categories of organic contaminants. The first grouping consists of those organic compounds that readily degrade biologically or chemically. The secon...

  20. Pilot-test of the calcium sodium phosphate (CNP) process for the stabilization/solidification of various mercury-contaminated wastes.

    PubMed

    Cho, Jae Han; Eom, Yujin; Lee, Tai Gyu

    2014-12-01

    A pilot-scale calcium sodium phosphate (CNP) plant was designed and manufactured to examine the performance of recently developed stabilization/solidification (S/S) technology. Hg-contaminated wastes samples generated via various industrial processes in Korea, including municipal, industrial, and medical waste incineration, wastewater treatment, and lime production, were collected and treated using the pilot-scale CNP plant. S/S samples were fabricated according to various operating conditions, including waste type, the dose of the stabilization reagent (Na2S), and the waste loading ratio. Although the performances (Hg leaching value and compressive strength) were reduced as the waste loading ratio increased, most of the S/S samples exhibited Hg leaching values that were below the universal treatment standard limit of 25 μg L(-1) and compressive strengths that exceeded the criterion of 3.45 MPa. PMID:25169648

  1. Potassium transport across rat alveolar epithelium: evidence for an apical Na+-K+ pump.

    PubMed

    Basset, G; Bouchonnet, F; Crone, C; Saumon, G

    1988-06-01

    5000 cm2). This value agrees with the passive permeabilities for mannitol, Na+ and Cl- suggesting that the paracellular pathway acts as a water-filled neutral channel. 5. We conclude that K+ is 'secreted' into the alveoli and is also removed from the alveoli, both processes being energized by Na+-K+-ATPases placed on the basolateral and apical sides, respectively. It is likely that two functionally different cell types exist in the alveolar membrane. One type ('B cell') has a Na+-K+-ATPase located at the basolateral membrane and K+ channels situated luminally.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3418536

  2. [Chemical food contaminants].

    PubMed

    Schrenk, D

    2004-09-01

    Chemical food contaminants are substances which are neither present naturally in the usual raw material used for food production nor are added during the regular production process. Examples are environmental pollutants or contaminants derived from agricultural production of crops or livestock or from inadequate manufacturing of the food product itself. More difficult is the classification of those compounds formed during regular manufacturing such as products of thermal processes including flavoring substances. In these cases, it is common practice to call those compounds contaminants which are known for their adverse effects such as acrylamide, whereas constituents which add to the food-specific flavor such as Maillard products formed during roasting, baking etc. are not termed contaminants. From a toxicological viewpoint this distinction is not always clear-cut. Important groups of chemical contaminants are metals such as mercury or lead, persistent organic pollutants such as polychlorinated biphenyls and related pollutants, which are regularly found in certain types of food originating from background levels of these compounds in our environment. Furthermore, natural toxins form microorganisms or plants, and compounds formed during thermal treatment of food are of major interest. In general, a scientific risk assessment has to be carried out for any known contaminant. This comprises an exposure analysis and a toxicological and epidemiological assessment. On these grounds, regulatory and/or technological measures can often improve the situation. Major conditions for a scientific risk assessment and a successful implementation of regulations are highly developed food quality control, food toxicology and nutritional epidemiology. PMID:15378171

  3. Contamination Control

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Upjohn Company sought a solution to their problem of potential particulate contamination of sterile injectable drugs. Contamination was caused by dust particles attracted by static electrical charge, which clung to plastic curtains in clean rooms. Upjohn found guidance in NASA Tech Briefs which provided detailed information for reducing static electricity. Guidelines for setting up static free work stations, materials and equipment needed to maintain antistatic protection.

  4. The Na+/K+/2Cl- cotransporter in the sea bass Dicentrarchus labrax during ontogeny: involvement in osmoregulation.

    PubMed

    Lorin-Nebel, Catherine; Boulo, Viviane; Bodinier, Charlotte; Charmantier, Guy

    2006-12-01

    This study combines a cellular and molecular analysis of the Na(+)/K(+)/2Cl(-) cotransporter (NKCC) to determine the osmoregulatory role of this protein in different tissues during the ontogeny of the sea bass. We have characterized the complete sequence of the NKCC1 isoform isolated from the sea bass gills and have identified, by immunofluorescence, NKCC1, and other isoforms, within the epithelium of the major osmoregulatory organs. Different (absorptive and secretory) functions have been attributed to this protein according to the tissue and salinity. The effects of short- (1-4 days), medium- (7-21 days) and long (6 months)-term freshwater (FW) adaptations were investigated, in comparison with seawater (SW)-maintained sea bass. In adult sea bass after long-term adaptation to FW and SW, the gills had the highest expression of NKCC mRNA compared with the median/posterior kidney and to the posterior intestine. Expression of NKCC mRNA in the kidney was 95% (SW) and 63% (FW) lower, and in the intestine 98% (SW) and 77% (FW) lower. Compared to SW-maintained sea bass, long-term FW adaptation induced a significant 5.6-fold decrease in the branchial NKCC gene expression whereas the intestinal and renal expressions did not vary significantly. The cells of the intestine and collecting ducts as well as a part of the epithelium lining the urinary bladder expressed NKCC apically. Within the gill chloride cells, NKCC was found basolaterally in SW-acclimated fish; some apically stained cells were detected after 7 days of FW exposure and their relative number increased progressively following FW acclimation. The appearance of FW-type chloride cells induces a functional shift of the gills from a secretory to an absorptive epithelium, which was only completed after long-term exposure to FW. Short- and medium-term exposure to FW induced a progressive decrease in total NKCC content and an increase in functionally different branchial chloride cells. During development, the

  5. Gene Expression Correlates with Process Rates Quantified for Sulfate- and Fe(III)-Reducing Bacteria in U(VI)-Contaminated Sediments

    PubMed Central

    Akob, Denise M.; Lee, Sang Hyon; Sheth, Mili; Küsel, Kirsten; Watson, David B.; Palumbo, Anthony V.; Kostka, Joel E.; Chin, Kuk-Jeong

    2012-01-01

    Though iron- and sulfate-reducing bacteria are well known for mediating uranium(VI) reduction in contaminated subsurface environments, quantifying the in situ activity of the microbial groups responsible remains a challenge. The objective of this study was to demonstrate the use of quantitative molecular tools that target mRNA transcripts of key genes related to Fe(III) and sulfate reduction pathways in order to monitor these processes during in situ U(VI) remediation in the subsurface. Expression of the Geobacteraceae-specific citrate synthase gene (gltA) and the dissimilatory (bi)sulfite reductase gene (dsrA), were correlated with the activity of iron- or sulfate-reducing microorganisms, respectively, under stimulated bioremediation conditions in microcosms of sediments sampled from the U.S. Department of Energy’s Oak Ridge Integrated Field Research Challenge (OR-IFRC) site at Oak Ridge, TN, USA. In addition, Geobacteraceae-specific gltA and dsrA transcript levels were determined in parallel with the predominant electron acceptors present in moderately and highly contaminated subsurface sediments from the OR-IFRC. Phylogenetic analysis of the cDNA generated from dsrA mRNA, sulfate-reducing bacteria-specific 16S rRNA, and gltA mRNA identified activity of specific microbial groups. Active sulfate reducers were members of the Desulfovibrio, Desulfobacterium, and Desulfotomaculum genera. Members of the subsurface Geobacter clade, closely related to uranium-reducing Geobacter uraniireducens and Geobacter daltonii, were the metabolically active iron-reducers in biostimulated microcosms and in situ core samples. Direct correlation of transcripts and process rates demonstrated evidence of competition between the functional guilds in subsurface sediments. We further showed that active populations of Fe(III)-reducing bacteria and sulfate-reducing bacteria are present in OR-IFRC sediments and are good potential targets for in situ bioremediation. PMID:22908009

  6. Biological Remediation of Petroleum Contaminants

    NASA Astrophysics Data System (ADS)

    Kuhad, Ramesh Chander; Gupta, Rishi

    Large volumes of hazardous wastes are generated in the form of oily sludges and contaminated soils during crude oil transportation and processing. Although many physical, chemical and biological treatment technologies are available for petroleum contaminants petroleum contaminants in soil, biological methods have been considered the most cost-effective. Practical biological remediation methods typically involve direct use of the microbes naturally occurring in the contaminated environment and/or cultured indigenous or modified microorganisms. Environmental and nutritional factors, including the properties of the soil, the chemical structure of the hydrocarbon(s), oxygen, water, nutrient availability, pH, temperature, and contaminant bioavailability, can significantly affect the rate and the extent of hydrocarbon biodegradation hydrocarbon biodegradation by microorganisms in contaminated soils. This chapter concisely discusses the major aspects of bioremediation of petroleum contaminants.

  7. Investigation of process performance and fouling mechanisms in micellar-enhanced ultrafiltration of nickel-contaminated waters.

    PubMed

    Danis, Ummuhan; Aydiner, Coskun

    2009-03-15

    Nickel removal from aqueous solution by micellar-enhanced ultrafiltration (MEUF) with relatively low transmembrane pressures was investigated at varying conditions of sodium lauryl ether sulfate (SLES) and nickel concentrations, transmembrane pressure and sodium chloride content. Process employed in continuous filtration mode, could be operated within a short time of 30 min presenting high rejection of nickel and SLES at high transient fluxes. Under the effect of increasing transmembrane pressure, the rejection of nickel and SLES increased, but the transient flux decreased. The existence of salt caused to decrease both rejections and flux. Nickel rejection, SLES rejection and flux were established as 98.6%, 75.7% and 0.304 m(3)/m(2)h, respectively, for the conditions of surfactant to metal (S/M) ratio of 10 (SLES = 2 mM), transmembrane pressure of 250 kPa without NaCl content at the end of 90-min operation time. The analyses related to the membrane fouling were carried out using adsorptive fouling models. It has been determined that, the fouling occurs as a dynamic function of various process conditions studied, and depends strongly on mechanisms controlled by the formation of gel layer and its bridging over the pore entrances simultaneously together with partial constriction of membrane pores by surfactant adsorption. PMID:18602749

  8. Reducing waste contamination from animal-processing plants by anaerobic thermophilic fermentation and by flesh fly digestion.

    PubMed

    Marchaim, U; Gelman, A; Braverman, Y

    2003-01-01

    There is currently no market in Israel for the large amounts of waste from fish- and poultry-processing plants. Therefore, this waste is incinerated, as part of the measures to prevent the spread of pathogens. Anaerobic methanogenic thermophilic fermentation (AMTF) of wastes from the cattle-slaughtering industry was examined previously, as an effective system to treat pathogenic bacteria, and in this article, we discuss a combined method of digestion by thermophilic anaerobic bacteria and by flesh flies, as a means of waste treatment. The AMTF process was applied to the wastes on a laboratory scale, and digestion by rearing of flesh fly (Phaenicia sericata) and housefly (Musca domestica) larvae on the untreated raw material was done on a small scale and showed remarkable weight conversion to larvae. The yield from degradation of poultry waste by flesh fly was 22.47% (SD = 3.89) and that from fish waste degradation was 35.34% (SD = 12.42), which is significantly higher than that from rearing houseflies on a regular rearing medium. Bacterial contents before and after thermophilic anaerobic digestion, as well as the changes in the chemical composition of the components during the rearing of larvae, were also examined. PMID:12794287

  9. Task 21 - Evaluation of Artificial Freeze Crystallization and Natural Freeze-Thaw Processes for the Treatment of Contaminated Groundwater at the Strachan Gas Plant in Alberta, Canada - Sour Gas Remediation Technology R{ampersand}D

    SciTech Connect

    1997-03-01

    During the period from 1993 to 1996, a long-term program was initiated to conduct remediation research at the Strachan Gas Plant in Alberta, Canada. As part of this research program, optimization of the existing pump-and-treat (P{ampersand}T) facility was of interest. The cost-effective treatment of contaminated groundwater produced from the P{ampersand}T system was complicated by several factors, including: (1) increased cost and reduced effectiveness of most water treatment processes because of the cold temperatures and severe winter conditions prevalent in Alberta, (2) interference caused by the mixture of inorganic and organic contaminants found in the groundwater that can reduce the effectiveness of many water treatment processes, and (3) pretreatment to prevent scaling in existing treatment process unit operations caused by the iron, manganese, and hardness of the contaminated groundwater.

  10. Adsorption/Membrane Filtration as a Contaminant Concentration and Separation Process for Mixed Wastes and Tank Wastes - Final Report

    SciTech Connect

    Benjamin, M.M.

    1999-10-01

    This project was conducted to evaluate novel approaches for removing radioactive strontium (Sr) and cesium (Cs) from the tank wastes. The bulk of the Sr removal research conducted as part of this project investigated adsorption of Sr onto a novel adsorbent known as iron-oxide-coated sand. The second major focus of the work was on the removal of cesium. Since the chemistries of strontium and cesium have little commonality, different materials (namely, cesium scavengers known as hexacyanoferrates, HCFs) were employed in these tests. This study bridged several scientific areas and yielded valuable knowledge for implementing new technological processes. The applicability of the results extends beyond the highly specialized application niches investigated experimentally to other issues of potential interest for EMSP programs (e.g., separation of chromium from a variety of wastes using IOCS, separation of Cs from neutral and acidic wastes with EC-controlled HCFs).

  11. On-line sensor monitoring for chemical contaminant attenuation during UV/H2O2 advanced oxidation process.

    PubMed

    Yu, Hye-Weon; Anumol, Tarun; Park, Minkyu; Pepper, Ian; Scheideler, Jens; Snyder, Shane A

    2015-09-15

    A combination of surrogate parameters and indicator compounds were measured to predict the removal efficiency of trace organic compounds (TOrCs) using low pressure (LP)-UV/H2O2 advanced oxidation process (AOP), engaged with online sensor-based monitoring system. Thirty-nine TOrCs were evaluated in two distinct secondary wastewater effluents in terms of estimated photochemical reactivity, as a function of the rate constants of UV direct photolysis (kUV) and hydroxyl radical (OH) oxidation (kOH). The selected eighteen TOrCs were classified into three groups that served as indicator compounds: Group 1 for photo-susceptible TOrCs but with minor degradation by OH oxidation (diclofenac, fluoxetine, iohexol, iopamidol, iopromide, simazine and sulfamethoxazole); Group 2 for TOrCs susceptible to both direct photolysis and OH oxidation (benzotriazole, diphenhydramine, ibuprofen, naproxen and sucralose); and Group 3 for photo-resistant TOrCs showing dominant degradation by OH oxidation (atenolol, carbamazepine, DEET, gemfibrozil, primidone and trimethoprim). The results indicate that TOC (optical-based measurement), UVA254 or UVT254 (UV absorbance or transmittance at 254 nm), and total fluorescence can all be used as suitable on-line organic surrogate parameters to predict the attenuation of TOrCs. Furthermore, the automated real-time monitoring via on-line surrogate sensors and equipped with the developed degradation profiles between sensor response and a group of TOrCs removal can provide a diagnostic tool for process control during advanced treatment of reclaimed waters. PMID:26074188

  12. Meat Processing Plant Microbiome and Contamination Patterns of Cold-Tolerant Bacteria Causing Food Safety and Spoilage Risks in the Manufacture of Vacuum-Packaged Cooked Sausages

    PubMed Central

    Rahkila, Riitta; Ali, Javeria; Rousu, Juho; Björkroth, K. Johanna

    2015-01-01

    Refrigerated food processing facilities are specific man-made niches likely to harbor cold-tolerant bacteria. To characterize this type of microbiota and study the link between processing plant and product microbiomes, we followed and compared microbiota associated with the raw materials and processing stages of a vacuum-packaged, cooked sausage product affected by a prolonged quality fluctuation with occasional spoilage manifestations during shelf life. A total of 195 samples were subjected to culturing and amplicon sequence analyses. Abundant mesophilic psychrotrophs were detected within the microbiomes throughout the different compartments of the production plant environment. However, each of the main genera of food safety and quality interest, e.g., Leuconostoc, Brochothrix, and Yersinia, had their own characteristic patterns of contamination. Bacteria from the genus Leuconostoc, commonly causing spoilage of cold-stored, modified-atmosphere-packaged foods, were detected in high abundance (up to >98%) in the sausages studied. The same operational taxonomic units (OTUs) were, however, detected in lower abundances in raw meat and emulsion (average relative abundance of 2% ± 5%), as well as on the processing plant surfaces (<4%). A completely different abundance profile was found for OTUs phylogenetically close to the species Yersinia pseudotuberculosis. These OTUs were detected in high abundance (up to 28%) on the processing plant surfaces but to a lesser extent (<1%) in raw meat, sausage emulsion, and sausages. The fact that Yersinia-like OTUs were found on the surfaces of a high-hygiene packaging compartment raises food safety concerns related to their resilient existence on surfaces. PMID:26231646

  13. Meat Processing Plant Microbiome and Contamination Patterns of Cold-Tolerant Bacteria Causing Food Safety and Spoilage Risks in the Manufacture of Vacuum-Packaged Cooked Sausages.

    PubMed

    Hultman, Jenni; Rahkila, Riitta; Ali, Javeria; Rousu, Juho; Björkroth, K Johanna

    2015-10-01

    Refrigerated food processing facilities are specific man-made niches likely to harbor cold-tolerant bacteria. To characterize this type of microbiota and study the link between processing plant and product microbiomes, we followed and compared microbiota associated with the raw materials and processing stages of a vacuum-packaged, cooked sausage product affected by a prolonged quality fluctuation with occasional spoilage manifestations during shelf life. A total of 195 samples were subjected to culturing and amplicon sequence analyses. Abundant mesophilic psychrotrophs were detected within the microbiomes throughout the different compartments of the production plant environment. However, each of the main genera of food safety and quality interest, e.g., Leuconostoc, Brochothrix, and Yersinia, had their own characteristic patterns of contamination. Bacteria from the genus Leuconostoc, commonly causing spoilage of cold-stored, modified-atmosphere-packaged foods, were detected in high abundance (up to >98%) in the sausages studied. The same operational taxonomic units (OTUs) were, however, detected in lower abundances in raw meat and emulsion (average relative abundance of 2%±5%), as well as on the processing plant surfaces (<4%). A completely different abundance profile was found for OTUs phylogenetically close to the species Yersinia pseudotuberculosis. These OTUs were detected in high abundance (up to 28%) on the processing plant surfaces but to a lesser extent (<1%) in raw meat, sausage emulsion, and sausages. The fact that Yersinia-like OTUs were found on the surfaces of a high-hygiene packaging compartment raises food safety concerns related to their resilient existence on surfaces. PMID:26231646

  14. Workplace and environmental air contaminant concentrations measured by open path Fourier transform infrared spectroscopy: a statistical process control technique to detect changes from normal operating conditions.

    PubMed

    Malachowski, M S; Levine, S P; Herrin, G; Spear, R C; Yost, M; Yi, Z

    1994-05-01

    Open path Fourier transform infrared (OP-FTIR) spectroscopy is a new air monitoring technique that can be used to measure concentrations of air contaminants in real or near-real time. OP-FTIR spectroscopy has been used to monitor workplace gas and vapor exposures, emissions from hazardous waste sites, and to track emissions along fence lines. This paper discusses a statistical process control technique that can be used with air monitoring data collected with an OP-FTIR spectrometer to detect departures from normal operating conditions in the workplace or along a fence line. Time series data, produced by plotting consecutive air sample concentrations in time, were analyzed. Autocorrelation in the time series data was removed by fitting dynamic models. Control charts were used with the residuals of the model fit data to determine if departures from defined normal operating conditions could be rapidly detected. Shewhart and exponentially weighted moving average (EWMA) control charts were evaluated for use with data collected under different room air flow and mixing conditions. Under rapidly changing conditions the Shewhart control chart was able to detect a leak in a simulated process area. The EWMA control chart was found to be more sensitive to drifts and slowly changing concentrations in air monitoring data. The time series and statistical process control techniques were also applied to data obtained during a field study at a chemical plant. A production area of an acrylonitrile, 1,3-butadiene, and styrene (ABS) polymer process was monitored in near-real time. Decision logics based on the time series and statistical process control technique introduced suggest several applications in workplace and environmental monitoring. These applications might include signaling of an alarm or warning, increasing levels of worker respiratory protection, or evacuation of a community, when gas and vapor concentrations are determined to be out-of-control. PMID:8012765

  15. In situ removal of contamination from soil

    DOEpatents

    Lindgren, E.R.; Brady, P.V.

    1997-10-14

    A process of remediation of cationic heavy metal contamination from soil utilizes gas phase manipulation to inhibit biodegradation of a chelating agent that is used in an electrokinesis process to remove the contamination. The process also uses further gas phase manipulation to stimulate biodegradation of the chelating agent after the contamination has been removed. The process ensures that the chelating agent is not attacked by bioorganisms in the soil prior to removal of the