WorldWideScience

Sample records for mercury control systems

  1. Enhancement of mercury control in flue-gas cleanup systems

    Energy Technology Data Exchange (ETDEWEB)

    Livengood, C.D.; Huang, Hann S.; Mendelsohn, M.H.; Wu, Jiann M.

    1996-07-01

    This paper summarizes research at Argonne National Laboratory which is focused on techniques to enhance the capture of elemental mercury and integrate its control into existing flue-gas cleanup (FGC) systems. Both laboratory and field tests have shown that very little elemental mercury is captured in a wet scrubber system due to the low solubility of that species. To enhance the ability of wet scrubbers to capture mercury, Argonne has studied improved mass transfer through both mechanical and chemical means, as well as the conversion of elemental mercury into a more soluble species that can be easily absorbed. Current research is investigating the roles of several halogen species either alone or in combination with typical flue-gas components such as sulfur dioxide and nitric oxide in the oxidation of mercury to form compounds that are easily scrubbed from the flue gas.

  2. Method and apparatus for controlling the flow rate of mercury in a flow system

    Science.gov (United States)

    Grossman, Mark W.; Speer, Richard

    1991-01-01

    A method for increasing the mercury flow rate to a photochemical mercury enrichment utilizing an entrainment system comprises the steps of passing a carrier gas over a pool of mercury maintained at a first temperature T1, wherein the carrier gas entrains mercury vapor; passing said mercury vapor entrained carrier gas to a second temperature zone T2 having temperature less than T1 to condense said entrained mercury vapor, thereby producing a saturated Hg condition in the carrier gas; and passing said saturated Hg carrier gas to said photochemical enrichment reactor.

  3. FIELD TEST PROGRAM TO DEVELOP COMPREHENSIVE DESIGN, OPERATING, AND COST DATA FOR MERCURY CONTROL SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Michael D. Durham

    2003-05-01

    With the Nation's coal-burning utilities facing the possibility of tighter controls on mercury pollutants, the U.S. Department of Energy is funding projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Mercury is known to have toxic effects on the nervous system of humans and wildlife. Although it exists only in trace amounts in coal, mercury is released when coal burns and can accumulate on land and in water. In water, bacteria transform the metal into methylmercury, the most hazardous form of the metal. Methylmercury can collect in fish and marine mammals in concentrations hundreds of thousands times higher than the levels in surrounding waters. One of the goals of DOE is to develop technologies by 2005 that will be capable of cutting mercury emissions 50 to 70 percent at well under one-half of today's costs. ADA Environmental Solutions (ADA-ES) is managing a project to test mercury control technologies at full scale at four different power plants from 2000--2003. The ADA-ES project is focused on those power plants that are not equipped with wet flue gas desulfurization systems. ADA-ES has developed a portable system that will be tested at four different utility power plants. Each of the plants is equipped with either electrostatic precipitators or fabric filters to remove solid particles from the plant's flue gas. ADA-ES's technology will inject a dry sorbent, such as activated carbon, which removes the mercury and makes it more susceptible to capture by the particulate control devices. A fine water mist may be sprayed into the flue gas to cool its temperature to the range where the dry sorbent is most effective. PG&E National Energy Group is providing two test sites that fire bituminous coals and both are equipped with electrostatic precipitators and carbon/ash separation systems. Wisconsin Electric Power Company is providing a third test site that burns Powder River Basin (PRB) coal and

  4. FIELD TEST PROGRAM TO DEVELOP COMPREHENSIVE DESIGN, OPERATING, AND COST DATA FOR MERCURY CONTROL SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Michael D. Durham

    2004-10-01

    PG&E NEG Salem Harbor Station Unit 1 was successfully tested for applicability of activated carbon injection as a mercury control technology. Test results from this site have enabled a thorough evaluation of mercury control at Salem Harbor Unit 1, including performance, estimated cost, and operation data. This unit has very high native mercury removal, thus it was important to understand the impacts of process variables on native mercury capture. The team responsible for executing this program included plant and PG&E headquarters personnel, EPRI and several of its member companies, DOE, ADA, Norit Americas, Inc., Hamon Research-Cottrell, Apogee Scientific, TRC Environmental Corporation, Reaction Engineering, as well as other laboratories. The technical support of all of these entities came together to make this program achieve its goals. Overall the objectives of this field test program were to determine the mercury control and balance-of-plant impacts resulting from activated carbon injection into a full-scale ESP on Salem Harbor Unit 1, a low sulfur bituminous-coal-fired 86 MW unit. It was also important to understand the impacts of process variables on native mercury removal (>85%). One half of the gas stream was used for these tests, or 43 MWe. Activated carbon, DARCO FGD supplied by NORIT Americas, was injected upstream of the cold side ESP, just downstream of the air preheater. This allowed for approximately 1.5 seconds residence time in the duct before entering the ESP. Conditions tested in this field evaluation included the impacts of the Selective Non-Catalytic Reduction (SNCR) system on mercury capture, of unburned carbon in the fly ash, of adjusting ESP inlet flue gas temperatures, and of boiler load on mercury control. The field evaluation conducted at Salem Harbor looked at several sorbent injection concentrations at several flue gas temperatures. It was noted that at the mid temperature range of 322-327 F, the LOI (unburned carbon) lost some of its

  5. Control, synchronization, and enhanced reliability of aperiodic oscillations in the Mercury Beating Heart system

    Science.gov (United States)

    Kumar, Pawan; Parmananda, P.

    2018-04-01

    Experiments involving the Mercury Beating Heart (MBH) oscillator, exhibiting irregular (aperiodic) dynamics, are performed. In the first set of experiments, control over irregular dynamics of the MBH oscillator was obtained via a superimposed periodic voltage signal. These irregular (aperiodic) dynamics were recovered once the control was switched off. Subsequently, two MBH oscillators were coupled to attain synchronization of their aperiodic oscillations. Finally, two uncoupled MBH oscillators were subjected, repeatedly, to a common stochastic forcing, resulting in an enhancement of their mutual phase correlation.

  6. FIELD TEST PROGRAM TO DEVELOP COMPREHENSIVE DESIGN, OPERATING, AND COST DATA FOR MERCURY CONTROL SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Michael D. Durham

    2005-03-17

    Brayton Point Unit 1 was successfully tested for applicability of activated carbon injection as a mercury control technology. Test results from this site have enabled a thorough evaluation of the impacts of future mercury regulations to Brayton Point Unit 1, including performance, estimated cost, and operation data. This unit has variable (29-75%) native mercury removal, thus it was important to understand the impacts of process variables and activated carbon on mercury capture. The team responsible for executing this program included: (1) Plant and PG&E National Energy Group corporate personnel; (2) Electric Power Research Institute (EPRI); (3) United States Department of Energy National Energy Technology Laboratory (DOE/NETL); (4) ADA-ES, Inc.; (5) NORIT Americas, Inc.; (6) Apogee Scientific, Inc.; (7) TRC Environmental Corporation; (8) URS Corporation; (9) Quinapoxet Solutions; (10) Energy and Environmental Strategies (EES); and (11) Reaction Engineering International (REI). The technical support of all of these entities came together to make this program achieve its goals. Overall, the objectives of this field test program were to determine the impact of activated carbon injection on mercury control and balance-of-plant processes on Brayton Point Unit 1. Brayton Point Unit 1 is a 250-MW unit that fires a low-sulfur eastern bituminous coal. Particulate control is achieved by two electrostatic precipitators (ESPs) in series. The full-scale tests were conducted on one-half of the flue gas stream (nominally 125 MW). Mercury control sorbents were injected in between the two ESPs. The residence time from the injection grid to the second ESP was approximately 0.5 seconds. In preparation for the full-scale tests, 12 different sorbents were evaluated in a slipstream of flue gas via a packed-bed field test apparatus for mercury adsorption. Results from these tests were used to determine the five carbon-based sorbents that were tested at full-scale. Conditions of interest

  7. MERCURY CONTROL WITH ADVANCED HYBRID PARTICULATE COLLECTOR

    Energy Technology Data Exchange (ETDEWEB)

    Ye Zhuang; Stanley J. Miller

    2005-05-01

    This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-00NT40769 and specifically addressed Technical Topical Area 4-Testing Novel and Less Mature Control Technologies on Actual Flue Gas at the Pilot Scale. The project team included the Energy & Environmental Research Center (EERC) as the main contractor; W.L. Gore & Associates, Inc., as a technical and financial partner; and the Big Stone Power Plant operated by Otter Tail Power Company, host for the field-testing portion of the research. Since 1995, DOE has supported development of a new concept in particulate control called the advanced hybrid particulate collector (AHPC). The AHPC has been licensed to W.L. Gore & Associates, Inc., and has been marketed as the Advanced Hybrid{trademark} filter by Gore. The Advanced Hybrid{trademark} filter combines the best features of electrostatic precipitators (ESPs) and baghouses in a unique configuration, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The Advanced Hybrid{trademark} filter provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and it solves the problem of reentrainment and re-collection of dust in conventional baghouses. The Advanced Hybrid{trademark} filter also appears to have unique advantages for mercury control over baghouses or ESPs as an excellent gas--solid contactor. The objective of the project was to demonstrate 90% total mercury control in the Advanced Hybrid{trademark} filter at a lower cost than current mercury control estimates. The approach included bench-scale batch tests, larger-scale pilot testing with real flue gas on a coal-fired combustion system, and field demonstration at the 2.5-MW (9000-acfm) scale at a utility power plant to prove scale-up and demonstrate longer-term mercury control

  8. Apparatus for control of mercury

    Science.gov (United States)

    Downs, William; Bailey, Ralph T.

    2001-01-01

    A method and apparatus for reducing mercury in industrial gases such as the flue gas produced by the combustion of fossil fuels such as coal adds hydrogen sulfide to the flue gas in or just before a scrubber of the industrial process which contains the wet scrubber. The method and apparatus of the present invention is applicable to installations employing either wet or dry scrubber flue gas desulfurization systems. The present invention uses kraft green liquor as a source for hydrogen sulfide and/or the injection of mineral acids into the green liquor to release vaporous hydrogen sulfide in order to form mercury sulfide solids.

  9. Amended Silicated for Mercury Control

    Energy Technology Data Exchange (ETDEWEB)

    James Butz; Thomas Broderick; Craig Turchi

    2006-12-31

    Amended Silicates{trademark}, a powdered, noncarbon mercury-control sorbent, was tested at Duke Energy's Miami Fort Station, Unit 6 during the first quarter of 2006. Unit 6 is a 175-MW boiler with a cold-side electrostatic precipitator (ESP). The plant burns run-of-the-river eastern bituminous coal with typical ash contents ranging from 8-15% and sulfur contents from 1.6-2.6% on an as-received basis. The performance of the Amended Silicates sorbent was compared with that for powdered activated carbon (PAC). The trial began with a period of baseline monitoring during which no sorbent was injected. Sampling during this and subsequent periods indicated mercury capture by the native fly ash was less than 10%. After the baseline period, Amended Silicates sorbent was injected at several different ratios, followed by a 30-day trial at a fixed injection ratio of 5-6 lb/MMACF. After this period, PAC was injected to provide a comparison. Approximately 40% mercury control was achieved for both the Amended Silicates sorbent and PAC at injection ratios of 5-6 lbs/MMACF. Higher injection ratios did not achieve significantly increased removal. Similar removal efficiencies have been reported for PAC injection trials at other plants with cold-side ESPs, most notably for plants using medium to high sulfur coal. Sorbent injection did not detrimentally impact plant operations and testing confirmed that the use of Amended Silicates sorbent does not degrade fly ash quality (unlike PAC). The cost for mercury control using either PAC or Amended Silicates sorbent was estimated to be equivalent if fly ash sales are not a consideration. However, if the plant did sell fly ash, the effective cost for mercury control could more than double if those sales were no longer possible, due to lost by-product sales and additional cost for waste disposal. Accordingly, the use of Amended Silicates sorbent could reduce the overall cost of mercury control by 50% or more versus PAC for locations where

  10. Coal fired flue gas mercury emission controls

    CERN Document Server

    Wu, Jiang; Pan, Weiguo; Pan, Weiping

    2015-01-01

    Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of

  11. Potassium permanganate for mercury vapor environmental control

    Science.gov (United States)

    Kuivinen, D. E.

    1972-01-01

    Potassium permanganate (KMnO4) was evaluated for application in removing mercury vapor from exhaust air systems. The KMnO4 may be used in water solution with a liquid spray scrubber system or as a solid adsorber bed material when impregnated onto a zeolite. Air samples contaminated with as much as 112 mg/cu m of mercury were scrubbed to 0.06mg/cum with the KMnO4-impregnated zeolite (molecular sieve material). The water spray solution of permanganate was also found to be as effective as the impregnated zeolite. The KMnO4-impregnated zeolite was applied as a solid adsorber material to (1) a hardware decontamination system, (2) a model incinerator, and (3) a high vacuum chamber for ion engine testing with mercury as the propellant. A liquid scrubber system was also applied in an incinerator system. Based on the results of these experiments, it is concluded that the use of KMnO4 can be an effective method for controlling noxious mercury vapor.

  12. Enhancing Carbon Reactivity in Mercury Control in Lignite-Fired Systems

    Energy Technology Data Exchange (ETDEWEB)

    Chad Wocken; Michael Holmes; John Pavlish; Jeffrey Thompson; Katie Brandt; Brandon Pavlish; Dennis Laudal; Kevin Galbreath; Michelle Olderbak

    2008-06-30

    This project was awarded through the U.S. Department of Energy (DOE) National Energy Technology Laboratory Program Solicitation DE-PS26-03NT41718-01. The Energy & Environmental Research Center (EERC) led a consortium-based effort to resolve mercury (Hg) control issues facing the lignite industry. The EERC team-the Electric Power Research Institute (EPRI); the URS Corporation; the Babcock & Wilcox Company; ADA-ES; Apogee; Basin Electric Power Cooperative; Otter Tail Power Company; Great River Energy; Texas Utilities; Montana-Dakota Utilities Co.; Minnkota Power Cooperative, Inc.; BNI Coal Ltd.; Dakota Westmoreland Corporation; the North American Coal Corporation; SaskPower; and the North Dakota Industrial Commission-demonstrated technologies that substantially enhanced the effectiveness of carbon sorbents to remove Hg from western fuel combustion gases and achieve a high level ({ge} 55% Hg removal) of cost-effective control. The results of this effort are applicable to virtually all utilities burning lignite and subbituminous coals in the United States and Canada. The enhancement processes were previously proven in pilot-scale and limited full-scale tests. Additional optimization testing continues on these enhancements. These four units included three lignite-fired units: Leland Olds Station Unit 1 (LOS1) and Stanton Station Unit 10 (SS10) near Stanton and Antelope Valley Station Unit 1 (AVS1) near Beulah and a subbituminous Powder River Basin (PRB)-fired unit: Stanton Station Unit 1 (SS1). This project was one of three conducted by the consortium under the DOE mercury program to systematically test Hg control technologies available for utilities burning lignite. The overall objective of the three projects was to field-test and verify options that may be applied cost-effectively by the lignite industry to reduce Hg emissions. The EERC, URS, and other team members tested sorbent injection technologies for plants equipped with electrostatic precipitators (ESPs) and

  13. Mercury Specie and Multi-Pollutant Control

    Energy Technology Data Exchange (ETDEWEB)

    Rob James; Virgil Joffrion; John McDermott; Steve Piche

    2010-05-31

    This project was awarded to demonstrate the ability to affect and optimize mercury speciation and multi-pollutant control using non-intrusive advanced sensor and optimization technologies. The intent was to demonstrate plant-wide optimization systems on a large coal fired steam electric power plant in order to minimize emissions, including mercury (Hg), while maximizing efficiency and maintaining saleable byproducts. Advanced solutions utilizing state-of-the-art sensors and neural network-based optimization and control technologies were proposed to maximize the removal of mercury vapor from the boiler flue gas thereby resulting in lower uncontrolled releases of mercury into the atmosphere. Budget Period 1 (Phase I) - Included the installation of sensors, software system design and establishment of the as-found baseline operating metrics for pre-project and post-project data comparison. Budget Period 2 (Phase II) - Software was installed, data communications links from the sensors were verified, and modifications required to integrate the software system to the DCS were performed. Budget Period 3 (Phase III) - Included the validation and demonstration of all control systems and software, and the comparison of the optimized test results with the targets established for the project site. This report represents the final technical report for the project, covering the entire award period and representing the final results compared to project goals. NeuCo shouldered 61% of the total project cost; while DOE shouldered the remaining 39%. The DOE requires repayment of its investment. This repayment will result from commercial sales of the products developed under the project. NRG's Limestone power plant (formerly owned by Texas Genco) contributed the host site, human resources, and engineering support to ensure the project's success.

  14. Coal fired flue gas mercury emission controls

    International Nuclear Information System (INIS)

    Wu, Jiang; Pan, Weiguo; Cao, Yan; Pan, Weiping

    2015-01-01

    Mercury (Hg) is one of the most toxic heavy metals, harmful to both the environment and human health. Hg is released into the atmosphere from natural and anthropogenic sources and its emission control has caused much concern. This book introduces readers to Hg pollution from natural and anthropogenic sources and systematically describes coal-fired flue gas mercury emission control in industry, especially from coal-fired power stations. Mercury emission control theory and experimental research are demonstrated, including how elemental mercury is oxidized into oxidized mercury and the effect of flue gas contents on the mercury speciation transformation process. Mercury emission control methods, such as existing APCDs (air pollution control devices) at power stations, sorbent injection, additives in coal combustion and photo-catalytic methods are introduced in detail. Lab-scale, pilot-scale and full-scale experimental studies of sorbent injection conducted by the authors are presented systematically, helping researchers and engineers to understand how this approach reduces the mercury emissions in flue gas and to apply the methods in mercury emission control at coal-fired power stations.

  15. Alkaline sorbent injection for mercury control

    Science.gov (United States)

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  16. Control of mercury emissions: policies, technologies, and future trends

    OpenAIRE

    Rhee, Seung-Whee

    2015-01-01

    Seung-Whee Rhee Department of Environmental Engineering, Kyonggi University, Suwon, Republic of Korea Abstract: Owing to the Minamata Convention on Mercury and the Global Mercury Partnership, policies and regulations on mercury management in advanced countries were intensified by a mercury phaseout program in the mercury control strategy. In developing countries, the legislative or regulatory frameworks on mercury emissions are not established specifically, but mercury management is designed...

  17. Localized surface plasmon resonance mercury detection system and methods

    Science.gov (United States)

    James, Jay; Lucas, Donald; Crosby, Jeffrey Scott; Koshland, Catherine P.

    2016-03-22

    A mercury detection system that includes a flow cell having a mercury sensor, a light source and a light detector is provided. The mercury sensor includes a transparent substrate and a submonolayer of mercury absorbing nanoparticles, e.g., gold nanoparticles, on a surface of the substrate. Methods of determining whether mercury is present in a sample using the mercury sensors are also provided. The subject mercury detection systems and methods find use in a variety of different applications, including mercury detecting applications.

  18. Mercury erosion experiments for spallation target system

    International Nuclear Information System (INIS)

    Kinoshita, Hidetaka; Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro

    2003-01-01

    The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a plan to construct the spallation neutron source at the Tokai Research Establishment, JAERI, under the High-Intensity Proton Accelerator Project (J-PARC). A mercury circulation system has been designed so as to supply mercury to the target stably under the rated flow rate of 41 m 3 /hr. Then, it was necessary to confirm a mercury pump performance from the viewpoint of making the mercury circulation system feasible, and more, to investigate erosion rate under the mercury flow as well as an amount of mercury remained on the surface after drain from the viewpoints of mechanical strength relating to the lifetime and remote handling of mercury components. The mercury pump performance was tested under the mercury flow conditions by using an experimental gear pump, which had almost the same structure as a practical mercury pump to be expected in the mercury circulation system, and the erosion rates in a mercury pipeline as well as the amount of mercury remained on the surface were also investigated. The discharged flow rates of the experimental gear pump increased linearly with the rotation speed, so that the gear pump would work as the flow meter. Erosion rates obtained under the mercury velocity less than 1.6 m/s was found to be so small that decrease of pipeline wall thickness would be 390 μm after 30-year operation under the rated mercury velocity of 0.7 m/s. For the amount of remaining mercury on the pipeline, remaining rates of weight and volume were estimated at 50.7 g/m 2 and 3.74 Hg-cm 3 /m 2 , respectively. Applying these remaining rates of weight and volume to the mercury target, the remaining mercury was estimated at about 106.5 g and 7.9 cm 3 . Radioactivity of this remaining mercury volume was found to be three-order lower than that of the target casing. (author)

  19. System dynamic analyses on the JKJ mercury target and cold moderator systems

    International Nuclear Information System (INIS)

    Takahashi, Toshio; Kaminaga, Masanori; Kinoshita, Hidetaka; Aso, Tomokazu; Haga, Katsuhiro; Hino, Ryutaro

    2001-01-01

    The temperature responses of major points in a mercury target cooling system and in a cold moderator system of JKJ (JAERI/KEK Joint Project) were simulated by the analytical code MATLAB (SIMULINK). As a result, it was made clear that non-control of mercury temperature is the best way to control the mercury target cooling system. If the mercury temperature of the system is controlled by the PID control system using an outlet temperature of heat exchanger, the PID control system shows the characteristics of an on-off control system, and the temperature cannot be controlled. Analytical results also showed that mercury temperature remained below the boiling point of 356degC under 0.1 MPa during a transient at one cooling pump trip. Analytical results for the cold moderator system showed that the outlet temperature of cold moderator vessels could be kept within a temperature range of 1 k during steady-state conditions. (author)

  20. Mercury

    Science.gov (United States)

    ... build up in fish, shellfish, and animals that eat fish. The nervous system is sensitive to all forms of mercury. Exposure to high levels can damage the brain and kidneys. Pregnant women can pass the mercury in their bodies to their babies. It is important to protect your family from ...

  1. FIELD TEST PROGRAM TO DEVELOP COMPREHENSIVE DESIGN, OPERATING AND COST DATA FOR MERCURY CONTROL SYSTEMS ON NON-SCRUBBED COAL-FIRED BOILERS

    International Nuclear Information System (INIS)

    C. Jean Bustard

    2001-01-01

    With the Nation's coal-burning utilities facing the possibility of tighter controls on mercury pollutants, the U.S. Department of Energy is funding projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Mercury is known to have toxic effects on the nervous system of humans and wildlife. Although it exists only in trace amounts in coal, mercury is released when coal burns and can accumulate on land and in water. In water, bacteria transform the metal into methylmercury, the most hazardous form of the metal. Methylmercury can collect in fish and marine mammals in concentrations hundreds of thousands times higher than the levels in surrounding waters. One of the goals of DOE is to develop technologies by 2005 that will be capable of cutting mercury emissions 50 to 70 percent at well under one-half of today's costs. ADA Environmental Solutions (ADA-ES) is managing a project to test mercury control technologies at full scale at four different power plants from 2000-2003. The ADA-ES project is focused on those power plants that are not equipped with wet flue gas desulfurization systems. ADA-ES will develop a portable system that will be moved to four different utility power plants for field testing. Each of the plants is equipped with either electrostatic precipitators or fabric filters to remove solid particles from the plant's flue gas. ADA-ES's technology will inject a dry sorbent, such as fly ash or activated carbon, that removes the mercury and makes it more susceptible to capture by the particulate control devices. A fine water mist may be sprayed into the flue gas to cool its temperature to the range where the dry sorbent is most effective. PG and E National Energy Group is providing two test sites that fire bituminous coals and are both equipped with electrostatic precipitators and carbon/ash separation systems. Wisconsin Electric Power Company is providing a third test site that burns Powder River Basin coal

  2. FIELD TEST PROGRAM TO DEVELOP COMPREHENSIVE DESIGN, OPERATING AND COST DATA FOR MERCURY CONTROL SYSTEMS ON NON-SCRUBBED COAL-FIRED BOILERS

    International Nuclear Information System (INIS)

    Richard Schlager

    2002-01-01

    With the Nation's coal-burning utilities facing the possibility of tighter controls on mercury pollutants, the U.S. Department of Energy is funding projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Mercury is known to have toxic effects on the nervous system of humans and wildlife. Although it exists only in trace amounts in coal, mercury is released when coal burns and can accumulate on land and in water. In water, bacteria transform the metal into methylmercury, the most hazardous form of the metal. Methylmercury can collect in fish and marine mammals in concentrations hundreds of thousands times higher than the levels in surrounding waters. One of the goals of DOE is to develop technologies by 2005 that will be capable of cutting mercury emissions 50 to 70 percent at well under one-half of today's costs. ADA Environmental Solutions (ADA-ES) is managing a project to test mercury control technologies at full scale at four different power plants from 2000-2003. The ADA-ES project is focused on those power plants that are not equipped with wet flue gas desulfurization systems. ADA-ES will develop a portable system that will be moved to four different utility power plants for field testing. Each of the plants is equipped with either electrostatic precipitators or fabric filters to remove solid particles from the plant's flue gas. ADA-ES's technology will inject a dry sorbent, such as fly ash or activated carbon, that removes the mercury and makes it more susceptible to capture by the particulate control devices. A fine water mist may be sprayed into the flue gas to cool its temperature to the range where the dry sorbent is most effective. PG and E National Energy Group is providing two test sites that fire bituminous coals and are both equipped with electrostatic precipitators and carbon/ash separation systems. Wisconsin Electric Power Company is providing a third test site that burns Powder River Basin (PRB

  3. FIELD TEST PROGRAM TO DEVELOP COMPREHENSIVE DESIGN, OPERATING AND COST DATA FOR MERCURY CONTROL SYSTEMS ON NON-SCRUBBED COAL-FIRED BOILERS

    International Nuclear Information System (INIS)

    C. Jean Bustard

    2001-01-01

    With the Nation's coal-burning utilities facing the possibility of tighter controls on mercury pollutants, the U.S. Department of Energy is funding projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Mercury is known to have toxic effects on the nervous system of humans and wildlife. Although it exists only in trace amounts in coal, mercury is released when coal burns and can accumulate on land and in water. In water, bacteria transform the metal into methylmercury, the most hazardous form of the metal. Methylmercury can collect in fish and marine mammals in concentrations hundreds of thousands times higher than the levels in surrounding waters. One of the goals of DOE is to develop technologies by 2005 that will be capable of cutting mercury emissions 50 to 70 percent at well under one-half of today's costs. ADA Environmental Solutions (ADA-ES) is managing a project to test mercury control technologies at full scale at four different power plants from 2000 to 2003. The ADA-ES project is focused on those power plants that are not equipped with wet flue gas desulfurization systems. ADA-ES will develop a portable system that will be moved to four different utility power plants for field testing. Each of the plants is equipped with either electrostatic precipitators or fabric filters to remove solid particles from the plant's flue gas. ADA-ES's technology will inject a dry sorbent, such as fly ash or activated carbon, that removes the mercury and makes it more susceptible to capture by the particulate control devices. A fine water mist may be sprayed into the flue gas to cool its temperature to the range where the dry sorbent is most effective. PG and E National Energy Group is providing two test sites that fire bituminous coals and are both equipped with electrostatic precipitators and carbon/ash separation systems. Wisconsin Electric Power Company is providing a third test site that burns Powder River Basin (PRB

  4. FIELD TEST PROGRAM TO DEVELOP COMPREHENSIVE DESIGN, OPERATING AND COST DATA FOR MERCURY CONTROL SYSTEMS ON NON-SCRUBBED COAL-FIRED BOILERS

    International Nuclear Information System (INIS)

    C. Jean Bustard

    2001-01-01

    With the Nation's coal-burning utilities facing the possibility of tighter controls on mercury pollutants, the U.S. Department of Energy is funding projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Mercury is known to have toxic effects on the nervous system of humans and wildlife. Although it exists only in trace amounts in coal, mercury is released when coal burns and can accumulate on land and in water. In water, bacteria transform the metal into methylmercury, the most hazardous form of the metal. Methylmercury can collect in fish and marine mammals in concentrations hundreds of thousands times higher than the levels in surrounding waters. One of the goals of DOE is to develop technologies by 2005 that will be capable of cutting mercury emissions 50 to 70 percent at well under one-half of today's costs. ADA Environmental Solutions (ADA-ES) is managing a project to test mercury control technologies at full scale at four different power plants from 2000-2003. The ADA-ES project is focused on those power plants that are not equipped with wet flue gas desulfurization systems. ADA-ES will develop a portable system that will be moved to four different utility power plants for field testing. Each of the plants is equipped with either electrostatic precipitators or fabric filters to remove solid particles from the plant's flue gas. ADA-ES's technology will inject a dry sorbent, such as fly ash or activated carbon, that removes the mercury and makes it more susceptible to capture by the particulate control devices. A fine water mist may be sprayed into the flue gas to cool its temperature to the range where the dry sorbent is most effective. PG and E National Energy Group is providing two test sites that fire bituminous coals and are both equipped with electrostatic precipitators and carbon/ash separation systems. Wisconsin Electric Power Company is providing a third test site that burns Powder River Basin (PRB

  5. Mercury- Distributed Metadata Management, Data Discovery and Access System

    Science.gov (United States)

    Palanisamy, Giri; Wilson, Bruce E.; Devarakonda, Ranjeet; Green, James M.

    2007-12-01

    Mercury is a federated metadata harvesting, search and retrieval tool based on both open source and ORNL- developed software. It was originally developed for NASA, and the Mercury development consortium now includes funding from NASA, USGS, and DOE. Mercury supports various metadata standards including XML, Z39.50, FGDC, Dublin-Core, Darwin-Core, EML, and ISO-19115 (under development). Mercury provides a single portal to information contained in disparate data management systems. It collects metadata and key data from contributing project servers distributed around the world and builds a centralized index. The Mercury search interfaces then allow the users to perform simple, fielded, spatial and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fast search results to the user, while allowing data providers to advertise the availability of their data and maintain complete control and ownership of that data. Mercury supports various projects including: ORNL DAAC, NBII, DADDI, LBA, NARSTO, CDIAC, OCEAN, I3N, IAI, ESIP and ARM. The new Mercury system is based on a Service Oriented Architecture and supports various services such as Thesaurus Service, Gazetteer Web Service and UDDI Directory Services. This system also provides various search services including: RSS, Geo-RSS, OpenSearch, Web Services and Portlets. Other features include: Filtering and dynamic sorting of search results, book-markable search results, save, retrieve, and modify search criteria.

  6. Mercury Emission Control Technologies for PPL Montana-Colstrip Testing

    Energy Technology Data Exchange (ETDEWEB)

    John P. Kay; Michael L. Jones; Steven A. Benson

    2007-04-01

    The Energy & Environmental Research Center (EERC) was asked by PPL Montana LLC (PPL) to provide assistance and develop an approach to identify cost-effective options for mercury control at its coal-fired power plants. The work conducted focused on baseline mercury level and speciation measurement, short-term parametric testing, and week long testing of mercury control technology at Colstrip Unit 3. Three techniques and various combinations of these techniques were identified as viable options for mercury control. The options included oxidizing agents or sorbent enhancement additives (SEAs) such as chlorine-based SEA1 and an EERC proprietary SEA2 with and without activated carbon injection. Baseline mercury emissions from Colstrip Unit 3 are comparatively low relative to other Powder River Basin (PRB) coal-fired systems and were found to range from 5 to 6.5 g/Nm3 (2.9 to 3.8 lb/TBtu), with a rough value of approximately 80% being elemental upstream of the scrubber and higher than 95% being elemental at the outlet. Levels in the stack were also greater than 95% elemental. Baseline mercury removal across the scrubber is fairly variable but generally tends to be about 5% to 10%. Parametric results of carbon injection alone yielded minimal reduction in Hg emissions. SEA1 injection resulted in 20% additional reduction over baseline with the maximum rate of 400 ppm (3 gal/min). Week long testing was conducted with the combination of SEA2 and carbon, with injection rates of 75 ppm (10.3 lb/hr) and 1.5 lb/MMacf (40 lb/hr), respectively. Reduction was found to be an additional 30% and, overall during the testing period, was measured to be 38% across the scrubber. The novel additive injection method, known as novel SEA2, is several orders of magnitude safer and less expensive than current SEA2 injection methods. However, used in conjunction with this plant configuration, the technology did not demonstrate a significant level of mercury reduction. Near-future use of this

  7. 21 CFR 862.3600 - Mercury test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mercury test system. 862.3600 Section 862.3600....3600 Mercury test system. (a) Identification. A mercury test system is a device intended to measure mercury, a heavy metal, in human specimens. Measurements obtained by this device are used in the diagnosis...

  8. Mercury

    International Nuclear Information System (INIS)

    Vilas, F.; Chapman, C.R.; Matthews, M.S.

    1988-01-01

    Papers are presented on future observations of and missions to Mercury, the photometry and polarimetry of Mercury, the surface composition of Mercury from reflectance spectrophotometry, the Goldstone radar observations of Mercury, the radar observations of Mercury, the stratigraphy and geologic history of Mercury, the geomorphology of impact craters on Mercury, and the cratering record on Mercury and the origin of impacting objects. Consideration is also given to the tectonics of Mercury, the tectonic history of Mercury, Mercury's thermal history and the generation of its magnetic field, the rotational dynamics of Mercury and the state of its core, Mercury's magnetic field and interior, the magnetosphere of Mercury, and the Mercury atmosphere. Other papers are on the present bounds on the bulk composition of Mercury and the implications for planetary formation processes, the building stones of the planets, the origin and composition of Mercury, the formation of Mercury from planetesimals, and theoretical considerations on the strange density of Mercury

  9. Mercury sorbent delivery system for flue gas

    Science.gov (United States)

    Klunder,; Edgar, B [Bethel Park, PA

    2009-02-24

    The invention presents a device for the removal of elemental mercury from flue gas streams utilizing a layer of activated carbon particles contained within the filter fabric of a filter bag for use in a flue gas scrubbing system.

  10. Large-Scale Mercury Control Technology Testing for Lignite-Fired Utilities - Oxidation Systems for Wet FGD

    Energy Technology Data Exchange (ETDEWEB)

    Steven A. Benson; Michael J. Holmes; Donald P. McCollor; Jill M. Mackenzie; Charlene R. Crocker; Lingbu Kong; Kevin C. Galbreath

    2007-03-31

    Mercury (Hg) control technologies were evaluated at Minnkota Power Cooperative's Milton R. Young (MRY) Station Unit 2, a 450-MW lignite-fired cyclone unit near Center, North Dakota, and TXU Energy's Monticello Steam Electric Station (MoSES) Unit 3, a 793-MW lignite--Powder River Basin (PRB) subbituminous coal-fired unit near Mt. Pleasant, Texas. A cold-side electrostatic precipitator (ESP) and wet flue gas desulfurization (FGD) scrubber are used at MRY and MoSES for controlling particulate and sulfur dioxide (SO{sub 2}) emissions, respectively. Several approaches for significantly and cost-effectively oxidizing elemental mercury (Hg{sup 0}) in lignite combustion flue gases, followed by capture in an ESP and/or FGD scrubber were evaluated. The project team involved in performing the technical aspects of the project included Babcock & Wilcox, the Energy & Environmental Research Center (EERC), the Electric Power Research Institute, and URS Corporation. Calcium bromide (CaBr{sub 2}), calcium chloride (CaCl{sub 2}), magnesium chloride (MgCl{sub 2}), and a proprietary sorbent enhancement additive (SEA), hereafter referred to as SEA2, were added to the lignite feeds to enhance Hg capture in the ESP and/or wet FGD. In addition, powdered activated carbon (PAC) was injected upstream of the ESP at MRY Unit 2. The work involved establishing Hg concentrations and removal rates across existing ESP and FGD units, determining costs associated with a given Hg removal efficiency, quantifying the balance-of-plant impacts of the control technologies, and facilitating technology commercialization. The primary project goal was to achieve ESP-FGD Hg removal efficiencies of {ge}55% at MRY and MoSES for about a month.

  11. Mercury emissions control technologies for mixed waste thermal treatment

    International Nuclear Information System (INIS)

    Chambers, A.; Knecht, M.; Soelberg, N.; Eaton, D.

    1997-01-01

    EPA has identified wet scrubbing at low mercury feedrates, as well as carbon adsorption via carbon injection into the offgas or via flow through fixed carbon beds, as control technologies that can be used to meet the proposed Maximum Achievable Control Technology (MACT) rule limit for mercury emissions from hazardous waste incinerators. DOE is currently funding demonstrations of gold amalgamation that may also control mercury to the desired levels. Performance data from a variety of sources was reviewed to determine ranges of achievable mercury control. Preliminary costs were estimated for using these technologies to control mercury emissions from mixed waste incineration. Mercury emissions control for mixed waste incineration may need to be more efficient than for incineration of other hazardous wastes because of higher mercury concentrations in some mixed waste streams. However, mercury control performance data for wet scrubbing and carbon adsorption is highly variable. More information is needed to demonstrate control efficiencies that are achievable under various design and operating conditions for wet scrubbing, carbon adsorption, and gold amalgamation technologies. Given certain assumptions made in this study, capital costs, operating costs, and lifecycle costs for carbon injection, carbon beds, and gold amalgamation generally vary for different assumed mercury feedrates and for different offgas flowrates. Assuming that these technologies can in fact provide the necessary mercury control performance, each of these technologies may be less costly than the others for certain mercury feedrates and the offgas flowrates

  12. Mercury Information Clearinghouse. Quarterly 3: advanced and developmental mercury control technologies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Advanced mercury control technologies for coal-fired electric utilities are reviewed. The technologies evaluated are at various stages of development and most have been tested under limited operational conditions. The following technologies are described: K-Fuel and K-Fuel Plus pre-combustion technology, combustion modification and in situ generation of sorbents, new sorbent developments, direct bromine injection, MerCAP{sup {trademark}} (Mercury Control via Adsorption Process, Gore felt filter bag inserts, EnviroScrub Pahlman{sup {trademark}} process, combined oxidation of NO{sub x} and mercury, and mercury control with the Advanced Hybrid{trademark} filter. 36 refs., 1 fig.

  13. Evaluation of Sorbent Injection for Mercury Control

    Energy Technology Data Exchange (ETDEWEB)

    Sharon Sjostrom

    2006-04-30

    The power industry in the U.S. is faced with meeting new regulations to reduce the emissions of mercury compounds from coal-fired plants. These regulations are directed at the existing fleet of nearly 1,100 boilers. These plants are relatively old with an average age of over 40 years. Although most of these units are capable of operating for many additional years, there is a desire to minimize large capital expenditures because of the reduced (and unknown) remaining life of the plant to amortize the project. Injecting a sorbent such as powdered activated carbon into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. This is the final site report for tests conducted at DTE Energy's Monroe Power Plant, one of five sites evaluated in this DOE/NETL program. The overall objective of the test program was to evaluate the capabilities of activated carbon injection at five plants: Sunflower Electric's Holcomb Station Unit 1, AmerenUE's Meramec Station Unit 2, Missouri Basin Power Project's Laramie River Station Unit 3, Detroit Edison's Monroe Power Plant Unit 4, and AEP's Conesville Station Unit 6. These plants have configurations that together represent 78% of the existing coal-fired generation plants. The goals for the program established by DOE/NETL were to reduce the uncontrolled mercury emissions by 50 to 70% at a cost 25 to 50% lower than the target established by DOE of $60,000/lb mercury removed. The results from Monroe indicate that using DARCO{reg_sign} Hg would result in higher mercury removal (80%) at a sorbent cost of $18,000/lb mercury, or 70% lower than the benchmark. These results demonstrate that the goals established by DOE/NETL were exceeded during this test program. The increase in mercury removal over baseline conditions is defined for this program as a comparison in the outlet emissions measured using the Ontario Hydro method during the baseline

  14. FIELD TEST PROGRAM TO DEVELOP COMPREHENSIVE DESIGN, OPERATING AND COST DATA FOR MERCURY CONTROL SYSTEMS ON NON-SCRUBBED COAL-FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    Richard Schlager

    2002-08-01

    With the Nation's coal-burning utilities facing the possibility of tighter controls on mercury pollutants, the U.S. Department of Energy is funding projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Mercury is known to have toxic effects on the nervous system of humans and wildlife. Although it exists only in trace amounts in coal, mercury is released when coal burns and can accumulate on land and in water. In water, bacteria transform the metal into methylmercury, the most hazardous form of the metal. Methylmercury can collect in fish and marine mammals in concentrations hundreds of thousands times higher than the levels in surrounding waters. One of the goals of DOE is to develop technologies by 2005 that will be capable of cutting mercury emissions 50 to 70 percent at well under one-half of today's costs. ADA Environmental Solutions (ADA-ES) is managing a project to test mercury control technologies at full scale at four different power plants from 2000-2003. The ADA-ES project is focused on those power plants that are not equipped with wet flue gas desulfurization systems. ADA-ES will develop a portable system that will be moved to four different utility power plants for field testing. Each of the plants is equipped with either electrostatic precipitators or fabric filters to remove solid particles from the plant's flue gas. ADA-ES's technology will inject a dry sorbent, such as fly ash or activated carbon, that removes the mercury and makes it more susceptible to capture by the particulate control devices. A fine water mist may be sprayed into the flue gas to cool its temperature to the range where the dry sorbent is most effective. PG&E National Energy Group is providing two test sites that fire bituminous coals and both are equipped with electrostatic precipitators and carbon/ash separation systems. Wisconsin Electric Power Company is providing a third test site that burns Powder

  15. Mercury Phase II Study - Mercury Behavior across the High-Level Waste Evaporator System

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, C. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jackson, D. G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shah, H. B. [Savannah River Remediation, LLC., Aiken, SC (United States); Jain, V. [Savannah River Remediation, LLC., Aiken, SC (United States); Occhipinti, J. E. [Savannah River Remediation, LLC., Aiken, SC (United States); Wilmarth, W. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-06-17

    The Mercury Program team’s effort continues to develop more fundamental information concerning mercury behavior across the liquid waste facilities and unit operations. Previously, the team examined the mercury chemistry across salt processing, including the Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU), and the Defense Waste Processing Facility (DWPF) flowsheets. This report documents the data and understanding of mercury across the high level waste 2H and 3H evaporator systems.

  16. Enhanced Control of Mercury and other HAPs by Innovative Modifications to Wet FGD Processes

    International Nuclear Information System (INIS)

    Hargrove, O.W.; Carey, T.R.; Richardson, C.F.; Skarupa, R.C.; Meserole, F.B.; Rhudy, R.G.; Brown, Thomas D.

    1997-01-01

    The overall objective of this project was to learn more about controlling emissions of hazardous air pollutants (HAPs) from coal-fired power plants that are equipped with wet flue gas desulfurization (FGD) systems. The project was included by FETC as a Phase I project in its Mega-PRDA program. Phase I of this project focused on three research areas. These areas in order of priority were: (1) Catalytic oxidation of vapor-phase elemental mercury; (2) Enhanced particulate-phase HAPs removal by electrostatic charging of liquid droplets; and (3) Enhanced mercury removal by addition of additives to FGD process liquor. Mercury can exist in two forms in utility flue gas--as elemental mercury and as oxidized mercury (predominant form believed to be HgCl 2 ). Previous test results have shown that wet scrubbers effectively remove the oxidized mercury from the gas but are ineffective in removing elemental mercury. Recent improvements in mercury speciation techniques confirm this finding. Catalytic oxidation of vapor-phase elemental mercury is of interest in cases where a wet scrubber exists or is planned for SO 2 control. If a loW--cost process could be developed to oxidize all of the elemental mercury in the flue gas, then the maximum achievable mercury removal across the existing or planned wet scrubber would increase. Other approaches for improving control of HAPs included a method for improving particulate removal across the FGD process and the use of additives to increase mercury solubility. This paper discusses results related only to catalytic oxidation of elemental mercury

  17. Mercury Information Clearinghouse. Quarterly 1: sorbent injection technologies for mercury control

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    Sorbent injection technologies for mercury control in coal-fired power plants and, in particular, the injection of activated carbon sorbents are examined. The retrofit technology that has been demonstrated to have the widest application for the control of mercury in plants without flue gas desulphurization scrubbers is discussed. The report covers mercury control requirements, laboratory studies on factors that affect sorbent capacity, pilot scale tests of the capture performance of different coals, research on sorbent properties, and full scale demonstration of sorbent control technologies. 34 refs., 3 figs., 4 tabs.

  18. Control of mercury emissions from coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.S.; Livengood, C.D.

    1992-09-01

    This project at Argonne is designed to investigate new concepts leading to advanced control technologies for fossil-energy systems. The objective of this new task on air toxics control is to develop new or improved, cost-effective control technology for the abatement of emissions of hazardous air pollutants (HAPs) from fossil-fuel combustion plants and to evaluate the possible effects of any captured species on waste disposal. The HAPs to be investigated initially in this task include mercury and arsenic compounds.

  19. Control of mercury emissions from coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.S.; Livengood, C.D.

    1992-01-01

    This project at Argonne is designed to investigate new concepts leading to advanced control technologies for fossil-energy systems. The objective of this new task on air toxics control is to develop new or improved, cost-effective control technology for the abatement of emissions of hazardous air pollutants (HAPs) from fossil-fuel combustion plants and to evaluate the possible effects of any captured species on waste disposal. The HAPs to be investigated initially in this task include mercury and arsenic compounds.

  20. Economic analysis of atmospheric mercury emission control for coal-fired power plants in China.

    Science.gov (United States)

    Ancora, Maria Pia; Zhang, Lei; Wang, Shuxiao; Schreifels, Jeremy; Hao, Jiming

    2015-07-01

    Coal combustion and mercury pollution are closely linked, and this relationship is particularly relevant in China, the world's largest coal consumer. This paper begins with a summary of recent China-specific studies on mercury removal by air pollution control technologies and then provides an economic analysis of mercury abatement from these emission control technologies at coal-fired power plants in China. This includes a cost-effectiveness analysis at the enterprise and sector level in China using 2010 as a baseline and projecting out to 2020 and 2030. Of the control technologies evaluated, the most cost-effective is a fabric filter installed upstream of the wet flue gas desulfurization system (FF+WFGD). Halogen injection (HI) is also a cost-effective mercury-specific control strategy, although it has not yet reached commercial maturity. The sector-level analysis shows that 193 tons of mercury was removed in 2010 in China's coal-fired power sector, with annualized mercury emission control costs of 2.7 billion Chinese Yuan. Under a projected 2030 Emission Control (EC) scenario with stringent mercury limits compared to Business As Usual (BAU) scenario, the increase of selective catalytic reduction systems (SCR) and the use of HI could contribute to 39 tons of mercury removal at a cost of 3.8 billion CNY. The economic analysis presented in this paper offers insights on air pollution control technologies and practices for enhancing atmospheric mercury control that can aid decision-making in policy design and private-sector investments. Copyright © 2015. Published by Elsevier B.V.

  1. Got Mercury?

    Science.gov (United States)

    Meyers, Valerie E.; McCoy, J. Torin; Garcia, Hector D.; James, John T.

    2009-01-01

    Many of the operational and payload lighting units used in various spacecraft contain elemental mercury. If these devices were damaged on-orbit, elemental mercury could be released into the cabin. Although there are plans to replace operational units with alternate light sources, such as LEDs, that do not contain mercury, mercury-containing lamps efficiently produce high quality illumination and may never be completely replaced on orbit. Therefore, exposure to elemental mercury during spaceflight will remain possible and represents a toxicological hazard. Elemental mercury is a liquid metal that vaporizes slowly at room temperature. However, it may be completely vaporized at the elevated operating temperatures of lamps. Although liquid mercury is not readily absorbed through the skin or digestive tract, mercury vapors are efficiently absorbed through the respiratory tract. Therefore, the amount of mercury in the vapor form must be estimated. For mercury releases from lamps that are not being operated, we utilized a study conducted by the New Jersey Department of Environmental Quality to calculate the amount of mercury vapor expected to form over a 2-week period. For longer missions and for mercury releases occurring when lamps are operating, we conservatively assumed complete volatilization of the available mercury. Because current spacecraft environmental control systems are unable to remove mercury vapors, both short-term and long-term exposures to mercury vapors are possible. Acute exposure to high concentrations of mercury vapors can cause irritation of the respiratory tract and behavioral symptoms, such as irritability and hyperactivity. Chronic exposure can result in damage to the nervous system (tremors, memory loss, insomnia, etc.) and kidneys (proteinurea). Therefore, the JSC Toxicology Group recommends that stringent safety controls and verifications (vibrational testing, etc.) be applied to any hardware that contains elemental mercury that could yield

  2. Mercury

    NARCIS (Netherlands)

    de Vries, Irma

    2017-01-01

    Mercury is a naturally occurring metal that exists in several physical and chemical forms. Inorganic mercury refers to compounds formed after the combining of mercury with elements such as chlorine, sulfur, or oxygen. After combining with carbon by covalent linkage, the compounds formed are called

  3. Interactions of mercury with different molecular weight fractions of humic substances in aquatic systems.

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Yao, K.M.; Chennuri, K.; Vudamala, K.; Babu, P.V.R.

    Interactions of mercury (Hg) with different molecular weight fractions of humic substances (HS) play an important role in controlling distribution, diffusion, speciation, and bioavailability of Hg in natural systems. This study suggests that Hg...

  4. Methods for measuring specific rates of mercury methylation and degradation and their use in determining factors controlling net rates of mercury methylation

    International Nuclear Information System (INIS)

    Ramlal, P.S.; Rudd, J.W.M.; Hecky, R.E.

    1986-01-01

    A method was developed to estimate specific rates of demethylation of methyl mercury in aquatic samples by measuring the volatile 14 C end products of 14 CH 3 HgI demethylation. This method was used in conjuction with a 203 Hg 2+ radiochemical method which determines specific rates of mercury methylation. Together, these methods enabled us to examine some factors controlling the net rate of mercury methylation. The methodologies were field tested, using lake sediment samples from a recently flooded reservoir in the Southern Indian Lake system which had developed a mercury contamination problem in fish. Ratios of the specific rates of methylation/demethylation were calculated. The highest ratios of methylation/demethylation were calculated. The highest ratios of methylation/demethylation occurred in the flooded shorelines of Southern Indian Lake. These results provide an explanation for the observed increases in the methyl mercury concentrations in fish after flooding

  5. Mercury: The Los Alamos ICF KrF laser system

    International Nuclear Information System (INIS)

    Czuchlewski, S.J.; York, G.W.; Bigio, I.J.; Brucker, J.; Hanson, D.; Honig, E.M.; Kurnit, N.; Leland, W.; McCown, A.W.; McLeod, J.; Rose, E.; Thomas, S.; Thompson, D.

    1993-01-01

    The Mercury KrF laser facility at Los Alamos is being built with the benefit of lessons learned from the Aurora system. An increased understanding of KrF laser engineering, and the designed implementation of system flexibility, will permit Mercury to serve as a tested for a variety of advanced KrF technology concepts

  6. Geochemical, Genetic, and Community Controls on Mercury

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Judy D.

    2014-11-10

    The sulfate-reducing bacteria (SRB) are soil bacteria that share two common characteristics, strict anaerobiosis and the ability to respire sulfate. The metabolic activities of these bacteria play significant roles in the global sulfur cycle, anaerobic degradation of biomass, biological metal corrosion in the environment and, recently, degradation of toxic compounds. The accumulation of evidence suggests these bacteria are also key to the production of the neurotoxin methylmercury in environmental settings. We propose to use our experience with the development of genetics in sulfate-reducing bacteria of the genus Desulfovibrio to create mutations that will eliminate the methylation of mercury, thereby identifying the genes essential for this process. This information may allow the environmental monitoring of the mercury methylation potential to learn the location and quantity of the production this toxin. From these data, more accurate predictive models of mercury cycling can be generated.

  7. Mercury

    Science.gov (United States)

    ... has set a limit of 2 parts of mercury per billion parts of drinking water (2 ppb). The Food and Drug Administration (FDA) has set a maximum permissible level of 1 part of methylmercury in a million ... of 0.1 milligram of organic mercury per cubic meter of workplace air (0.1 ...

  8. Optical System Design and Integration of the Mercury Laser Altimeter

    Science.gov (United States)

    Ramos-Izquierdo, Luis; Scott, V. Stanley, III; Schmidt, Stephen; Britt, Jamie; Mamakos, William; Trunzo, Raymond; Cavanaugh, John; Miller, Roger

    2005-01-01

    The Mercury Laser Altimeter (MLA). developed for the 2004 MESSENGER mission to Mercury, is designed to measure the planet's topography via laser ranging. A description of the MLA optical system and its measured optical performance during instrument-level and spacecraft-level integration and testing are presented.

  9. Low-Cost Options for Moderate Levels of Mercury Control

    Energy Technology Data Exchange (ETDEWEB)

    Sharon Sjostrom

    2006-03-31

    On March 15, 2005, EPA issued the Clean Air Mercury Rule, requiring phased-in reductions of mercury emissions from electric power generators. ADA-ES, Inc., with support from DOE/NETL and industry partners, is conducting evaluations of EPRI's TOXECON II{trademark} process and of high-temperature reagents and sorbents to determine the capabilities of sorbent/reagent injection, including activated carbon, for mercury control on different coals and air emissions control equipment configurations. DOE/NETL targets for total mercury removal are {ge}55% (lignite), {ge}65% (subbituminous), and {ge}80% (bituminous). Based on work done to date at various scales, meeting the removal targets appears feasible. However, work needs to progress to more thoroughly document and test these promising technologies at full scale. This is the final site report for tests conducted at MidAmerican's Louisa Station, one of three sites evaluated in this DOE/NETL program. The other two sites in the program are MidAmerican's Council Bluff Station and Entergy's Independence Station. MidAmerican's Louisa Station burns Powder River Basin (PRB) coal and employs hot-side electrostatic precipitators with flue gas conditioning for particulate control. This part of the testing program evaluated the effect of reagents used in the existing flue gas conditioning on mercury removal.

  10. Comparison of pollutant emission control strategies for cadmium and mercury in urban water systems using substance flow analysis

    DEFF Research Database (Denmark)

    Revitt, D. M.; Lundy, L.; Eriksson, Eva

    2013-01-01

    effective for one city (59% reduction of Hg; 39% reduction of Cd) and the other city being most influenced by the presence of efficient advanced wastewater treatment processes (63% reduction of Hg; 43% reduction of Cd). These reductions in receiving water loads are necessarily accompanied by either...... of urban emission control strategies (ECS) with an emphasis on the scientific and technological benefits which can be achieved. Data from the literature, in combination with expert judgement, have been used to develop two different semi-hypothetical case cities (SHCC), which represent virtual platforms...... to be particularly effective for Cd with the potential to further lower the overall emissions by between 16% and 27%. The most efficient protection of the receiving surface water environment is strongly influenced by the city characteristics with the introduction of stormwater treatment practices being particularly...

  11. Evaluation of MerCAP for Power Plant Mercury Control

    Energy Technology Data Exchange (ETDEWEB)

    Carl Richardson

    2008-09-30

    This report is submitted to the U.S. Department of Energy National Energy Technology Laboratory (DOE-NETL) as part of Cooperative Agreement DE-FC26-03NT41993, 'Evaluation of EPRI's MerCAP{trademark} Technology for Power Plant Mercury Control'. This project has investigated the mercury removal performance of EPRI's Mercury Capture by Amalgamation Process (MerCAP{trademark}) technology. Test programs were conducted to evaluate gold-based MerCAP{trademark} at Great River Energy's Stanton Station Unit 10 (Site 1), which fired both North Dakota lignite (NDL) and Power River Basin (PRB) coal during the testing period, and at Georgia Power's Plant Yates Unit 1 (Site 2) [Georgia Power is a subsidiary of The Southern Company] which fires a low sulfur Eastern bituminous coal. Additional tests were carried out at Alabama Power's Plant Miller, which fires Powder River Basin Coal, to evaluate a carbon-based MerCAP{trademark} process for removing mercury from flue gas downstream of an electrostatic precipitator [Alabama Power is a subsidiary of The Southern Company]. A full-scale gold-based sorbent array was installed in the clean-air plenum of a single baghouse compartment at GRE's Stanton Station Unit 10, thereby treating 1/10th of the unit's exhaust gas flow. The substrates that were installed were electroplated gold screens oriented parallel to the flue gas flow. The sorbent array was initially installed in late August of 2004, operating continuously until its removal in July 2006, after nearly 23 months. The initial 4 months of operation were conducted while the host unit was burning North Dakota lignite (NDL). In November 2004, the host unit switched fuel to burn Powder River Basin (PRB) subbituminous coal and continued to burn the PRB fuel for the final 19 months of this program. Tests were conducted at Site 1 to evaluate the impacts of flue gas flow rate, sorbent plate spacing, sorbent pre-cleaning and regeneration, and spray

  12. Biogeochemical controls on mercury methylation in the Allequash Creek wetland.

    Science.gov (United States)

    Creswell, Joel E; Shafer, Martin M; Babiarz, Christopher L; Tan, Sue-Zanne; Musinsky, Abbey L; Schott, Trevor H; Roden, Eric E; Armstrong, David E

    2017-06-01

    We measured mercury methylation potentials and a suite of related biogeochemical parameters in sediment cores and porewater from two geochemically distinct sites in the Allequash Creek wetland, northern Wisconsin, USA. We found a high degree of spatial variability in the methylation rate potentials but no significant differences between the two sites. We identified the primary geochemical factors controlling net methylmercury production at this site to be acid-volatile sulfide, dissolved organic carbon, total dissolved iron, and porewater iron(II). Season and demethylation rates also appear to regulate net methylmercury production. Our equilibrium speciation modeling demonstrated that sulfide likely regulated methylation rates by controlling the speciation of inorganic mercury and therefore its bioavailability to methylating bacteria. We found that no individual geochemical parameter could explain a significant amount of the observed variability in mercury methylation rates, but we found significant multivariate relationships, supporting the widely held understanding that net methylmercury production is balance of several simultaneously occurring processes.

  13. JV Task 98 - Controlling Mercury Emissions for Utilities Firing Lignites from North America

    Energy Technology Data Exchange (ETDEWEB)

    Steven Benson

    2007-06-15

    This project compiled and summarized the findings and conclusions of research, development, and demonstration projects on controlling mercury from lignite coals. A significant amount of work has been conducted since 1994 on mercury in lignite, mercury measurement in flue gases, sorbent, sorbent enhancement additives, oxidation agent development, and full-scale demonstration of mercury control technologies. This report is focused on providing the lignite industry with an understanding of mercury issues associated with the combustion of lignite, as well as providing vital information on the methods to control mercury emissions in coal-fired power plants.

  14. Global Mercury Observatory System Land-based Monitoring Data Portal

    Data.gov (United States)

    U.S. Environmental Protection Agency — Global Mercury Observation System On-line Data Portal. This dataset is associated with the following publication: Carbone, F., A. Bruno, A. Naccarato, F. De Simone,...

  15. Mercury

    CERN Document Server

    Balogh, André; Steiger, Rudolf

    2008-01-01

    Mercury, the planet closest to the Sun, is different in several respects from the other three terrestrial planets. In appearance, it resembles the heavily cratered surface of the Moon, but its density is high, it has a magnetic field and magnetosphere, but no atmosphere or ionosphere. This book reviews the progress made in Mercury studies since the flybys by Mariner 10 in 1974-75, based on the continued research using the Mariner 10 archive, on observations from Earth, and on increasingly realistic models of its interior evolution.

  16. Evaluation of activated carbon for control of mercury from coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Miller, S.; Laudal, D.; Dunham, G. [Univ. of North Dakota, Grand Forks, ND (United States)

    1995-11-01

    The ability to remove mercury from power plant flue gas may become important because of the Clean Air Act amendments` requirement that the U.S. Environmental Protection Agency (EPA) assess the health risks associated with these emissions. One approach for mercury removal, which may be relatively simple to retrofit, is the injection of sorbents, such as activated carbon, upstream of existing particulate control devices. Activated carbon has been reported to capture mercury when injected into flue gas upstream of a spray dryer baghouse system applied to waste incinerators or coal-fired boilers. However, the mercury capture ability of activated carbon injected upstream of an electrostatic precipitator (ESP) or baghouse operated at temperatures between 200{degrees} and 400{degrees}F is not well known. A study sponsored by the U.S. Department of Energy and the Electric power Research Institute is being conducted at the University of North Dakota Energy & Environmental Research Center (EERC) to evaluate whether mercury control with sorbents can be a cost-effective approach for large power plants. Initial results from the study were reported last year. This paper presents some of the recent project results. Variables of interest include coal type, sorbent type, sorbent addition rate, collection media, and temperature.

  17. Mercury in coal and the impact of coal quality on mercury emissions from combustion systems

    International Nuclear Information System (INIS)

    Kolker, Allan; Senior, Constance L.; Quick, Jeffrey C.

    2006-01-01

    The proportion of Hg in coal feedstock that is emitted by stack gases of utility power stations is a complex function of coal chemistry and properties, combustion conditions, and the positioning and type of air pollution control devices employed. Mercury in bituminous coal is found primarily within Fe-sulfides, whereas lower rank coal tends to have a greater proportion of organic-bound Hg. Preparation of bituminous coal to reduce S generally reduces input Hg relative to in-ground concentrations, but the amount of this reduction varies according to the fraction of Hg in sulfides and the efficiency of sulfide removal. The mode of occurrence of Hg in coal does not directly affect the speciation of Hg in the combustion flue gas. However, other constituents in the coal, notably Cl and S, and the combustion characteristics of the coal, influence the species of Hg that are formed in the flue gas and enter air pollution control devices. The formation of gaseous oxidized Hg or particulate-bound Hg occurs post-combustion; these forms of Hg can be in part captured in the air pollution control devices that exist on coal-fired boilers, without modification. For a given coal type, the capture efficiency of Hg by pollution control systems varies according to type of device and the conditions of its deployment. For bituminous coal, on average, more than 60% of Hg in flue gas is captured by fabric filter (FF) and flue-gas desulfurization (FGD) systems. Key variables affecting performance for Hg control include Cl and S content of the coal, the positioning (hot side vs. cold side) of the system, and the amount of unburned C in coal ash. Knowledge of coal quality parameters and their effect on the performance of air pollution control devices allows optimization of Hg capture co-benefit

  18. Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems

    Energy Technology Data Exchange (ETDEWEB)

    Gary Blythe; Conor Braman; Katherine Dombrowski; Tom Machalek

    2010-12-31

    This document is the final technical report for Cooperative Agreement DE-FC26-04NT41992, 'Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems,' which was conducted over the time-period January 1, 2004 through December 31, 2010. The objective of this project has been to demonstrate at pilot scale the use of solid catalysts and/or fixed-structure mercury sorbents to promote the removal of total mercury and oxidation of elemental mercury in flue gas from coal combustion, followed by wet flue gas desulfurization (FGD) to remove the oxidized mercury at high efficiency. The project was co-funded by the U.S. DOE National Energy Technology Laboratory (DOE-NETL), EPRI, Great River Energy (GRE), TXU Energy (now called Luminant), Southern Company, Salt River Project (SRP) and Duke Energy. URS Group was the prime contractor. The mercury control process under development uses fixed-structure sorbents and/or catalysts to promote the removal of total mercury and/or oxidation of elemental mercury in the flue gas from coal-fired power plants that have wet lime or limestone FGD systems. Oxidized mercury not adsorbed is removed in the wet FGD absorbers and leaves with the byproducts from the FGD system. The project has tested candidate materials at pilot scale and in a commercial form, to provide engineering data for future full-scale designs. Pilot-scale catalytic oxidation tests have been completed for periods of approximately 14 to19 months at three sites, with an additional round of pilot-scale fixed-structure sorbent tests being conducted at one of those sites. Additionally, pilot-scale wet FGD tests have been conducted downstream of mercury oxidation catalysts at a total of four sites. The sites include the two of three sites from this project and two sites where catalytic oxidation pilot testing was conducted as part of a previous DOE-NETL project. Pilot-scale wet FGD tests were also conducted at a fifth site, but with no catalyst or fixed

  19. Benefits of mercury controls for the United States.

    Science.gov (United States)

    Giang, Amanda; Selin, Noelle E

    2016-01-12

    Mercury pollution poses risks for both human and ecosystem health. As a consequence, controlling mercury pollution has become a policy goal on both global and national scales. We developed an assessment method linking global-scale atmospheric chemical transport modeling to regional-scale economic modeling to consistently evaluate the potential benefits to the United States of global (UN Minamata Convention on Mercury) and domestic [Mercury and Air Toxics Standards (MATS)] policies, framed as economic gains from avoiding mercury-related adverse health endpoints. This method attempts to trace the policies-to-impacts path while taking into account uncertainties and knowledge gaps with policy-appropriate bounding assumptions. We project that cumulative lifetime benefits from the Minamata Convention for individuals affected by 2050 are $339 billion (2005 USD), with a range from $1.4 billion to $575 billion in our sensitivity scenarios. Cumulative economy-wide benefits to the United States, realized by 2050, are $104 billion, with a range from $6 million to $171 billion. Projected Minamata benefits are more than twice those projected from the domestic policy. This relative benefit is robust to several uncertainties and variabilities, with the ratio of benefits (Minamata/MATS) ranging from ≈1.4 to 3. However, we find that for those consuming locally caught freshwater fish from the United States, rather than marine and estuarine fish from the global market, benefits are larger from US than global action, suggesting domestic policies are important for protecting these populations. Per megagram of prevented emissions, our domestic policy scenario results in US benefits about an order of magnitude higher than from our global scenario, further highlighting the importance of domestic action.

  20. Estimating mercury emissions from a zinc smelter in relation to China's mercury control policies

    International Nuclear Information System (INIS)

    Wang, S.X.; Song, J.X.; Li, G.H.; Wu, Y.; Zhang, L.; Wan, Q.; Streets, D.G.; Chin, Conrad K.; Hao, J.M.

    2010-01-01

    Mercury concentrations of flue gas at inlet/outlet of the flue gas cleaning, electrostatic demister, reclaiming tower, acid plant, and mercury contents in zinc concentrate and by-products were measured in a hydrometallurgical zinc smelter. The removal efficiency of flue gas cleaning, electrostatic demister, mercury reclaiming and acid plant was about 17.4%, 30.3%, 87.9% and 97.4% respectively. Flue gas cleaning and electrostatic demister captured 11.7% and 25.3% of the mercury in the zinc concentrate, respectively. The mercury reclaiming tower captured 58.3% of the mercury in the zinc concentrate. About 4.2% of the mercury in the zinc concentrate was captured by the acid plant. Consequently, only 0.8% of the mercury in the zinc concentrate was emitted to the atmosphere. The atmospheric mercury emission factor was 0.5 g t -1 of zinc produced for the tested smelter, indicating that this process offers the potential to effectively reduce mercury emissions from zinc smelting. - Modern scale production equipped with acid plant and Hg reclaiming tower will significantly reduce Hg emissions from zinc smelters in China.

  1. Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems

    Energy Technology Data Exchange (ETDEWEB)

    Richard Rhudy

    2006-06-30

    This final report presents and discusses results from a mercury control process development project entitled ''Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems''. The objective of this project was to demonstrate at pilot scale a mercury control technology that uses solid honeycomb catalysts to promote the oxidation of elemental mercury in the flue gas from coal combustion. Oxidized mercury is removed in downstream wet flue gas desulfurization (FGD) absorbers and leaves with the FGD byproducts. The goal of the project was to achieve 90% oxidation of elemental mercury in the flue gas and 90% overall mercury capture with the downstream wet FGD system. The project was co-funded by EPRI and the U.S. Department of Energy's National Energy Technology Laboratory (DOE NETL) under Cooperative Agreement DE-FC26-01NT41185. Great River Energy (GRE) and City Public Service (now CPS Energy) of San Antonio were also project co-funders and provided host sites. URS Group, Inc. was the prime contractor. Longer-term pilot-scale tests were conducted at two sites to provide catalyst life data. GRE provided the first site, at their Coal Creek Station (CCS), which fires North Dakota lignite, and CPS Energy provided the second site, at their Spruce Plant, which fires Powder River Basin (PRB) coal. Mercury oxidation catalyst testing began at CCS in October 2002 and continued through the end of June 2004, representing nearly 21 months of catalyst operation. An important finding was that, even though the mercury oxidation catalyst pilot unit was installed downstream of a high-efficiency ESP, fly ash buildup began to plug flue gas flow through the horizontal catalyst cells. Sonic horns were installed in each catalyst compartment and appeared to limit fly ash buildup. A palladium-based catalyst showed initial elemental mercury oxidation percentages of 95% across the catalyst, declining to 67% after 21 months in service. A carbon

  2. TFTR ultrahigh-vacuum pumping system incorporating mercury diffusion pumps

    International Nuclear Information System (INIS)

    Sink, D.A.; Sniderman, M.

    1976-06-01

    The TFTR vacuum vessel will have a system of four 61 cm diameter mercury diffusion pumps to provide a base pressure in the 10 -8 to 10 -9 Torr range as well as a low impurity level within the vessel. The system, called the Torus Vacuum Pumping System (TVPS), will be employed with the aid of an occasional 250 0 C bakeout in situ as well as periodic applications of aggressive discharge cleaning. The TVPS is an ultrahigh-vacuum (UHV) system using no elastomers as well as being a closed system with respect to tritium or any tritiated gases. The backing system employing approximately 75 all-metal isolation valves is designed with the features of redundancy and flexibility employed in a variety of ways to meet the fundamental requirements and functions enumerated for the TVPS. Since the design, is one which is a modification of the conceptual design of the TVPS, those features which have changed are discussed. Calculations are presented for the major performance parameters anticipated for the TVPS and include conductances, effective pumping speeds, base pressures, operating parameters, getter pump parameters, and calculations of time constants associated with leak checking. Modifications in the vacuum pumping system for the guard regions on the twelve bellows sections are presented so that it is compatible with the main TVPS. The bellows pumping system consists of a mechanical pump unit, a zirconium aluminum getter pump unit and a residual gas analyzer. The control and management of the TVPS is described with particular attention given to providing both manual and automatic control at a local station and at the TFTR Central Control. Such operations as testing, maintenance, leak checking, startup, bakeout, and various other operations are considered in some detail. Various aspects related to normal pulsing, discharge cleaning, non-tritium operations and tritium operations are also taken into consideration. A cost estimate is presented

  3. In-Flight performance of MESSENGER's Mercury dual imaging system

    Science.gov (United States)

    Hawkins, S.E.; Murchie, S.L.; Becker, K.J.; Selby, C.M.; Turner, F.S.; Noble, M.W.; Chabot, N.L.; Choo, T.H.; Darlington, E.H.; Denevi, B.W.; Domingue, D.L.; Ernst, C.M.; Holsclaw, G.M.; Laslo, N.R.; Mcclintock, W.E.; Prockter, L.M.; Robinson, M.S.; Solomon, S.C.; Sterner, R.E.

    2009-01-01

    The Mercury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, launched in August 2004 and planned for insertion into orbit around Mercury in 2011, has already completed two flybys of the innermost planet. The Mercury Dual Imaging System (MDIS) acquired nearly 2500 images from the first two flybys and viewed portions of Mercury's surface not viewed by Mariner 10 in 1974-1975. Mercury's proximity to the Sun and its slow rotation present challenges to the thermal design for a camera on an orbital mission around Mercury. In addition, strict limitations on spacecraft pointing and the highly elliptical orbit create challenges in attaining coverage at desired geometries and relatively uniform spatial resolution. The instrument designed to meet these challenges consists of dual imagers, a monochrome narrow-angle camera (NAC) with a 1.5?? field of view (FOV) and a multispectral wide-angle camera (WAC) with a 10.5?? FOV, co-aligned on a pivoting platform. The focal-plane electronics of each camera are identical and use a 1024??1024 charge-coupled device detector. The cameras are passively cooled but use diode heat pipes and phase-change-material thermal reservoirs to maintain the thermal configuration during the hot portions of the orbit. Here we present an overview of the instrument design and how the design meets its technical challenges. We also review results from the first two flybys, discuss the quality of MDIS data from the initial periods of data acquisition and how that compares with requirements, and summarize how in-flight tests are being used to improve the quality of the instrument calibration. ?? 2009 SPIE.

  4. Studies of Mercury in High Level Waste Systems

    Energy Technology Data Exchange (ETDEWEB)

    WILMARTH, WILLIAMR.

    2004-03-31

    Historically, mercury was added to the nuclear weapons processing as a catalyst for the dissolution of aluminum metal. After neutralization the mercury was disposed to the High Level Waste tanks where its speciation led to mercuric oxides/hydroxides in the sludge and a small soluble mercuric ion concentration in the alkaline supernate. This report in its original revision described a three-pronged approach for studying possible sources of elevated mercury vapor in and around the Tank Farm evaporator systems. This approach examined the engineering differences between the evaporator designs, the chemistry of mercury and its concentrations, and the potential for organomercury species.During the course of this work, the presence of dimethylmercury in the High Level Waste system was established. Vapor and liquid samples were analyzed from the three evaporator systems (2H, 2F, and 3H) along with the transfer lines leading to the Effluent Treatment Facility and tanks within the ETF. The magnitude of the dimethylmercury concentrations led to ventilation modifications at the 3H Evaporator and design for modifications at the 2H evaporator. Continued sampling efforts are aimed at understanding the boundaries of where dimethylmercury vapors exist.

  5. Evidence for the Presence of Colloidal Metacinnabar in Mercury-DOM-Sulfide Systems as Determined by a Chromatographic-EXAFS Method

    Science.gov (United States)

    Gerbig, C. A.; Kim, C. S.; Moreau, J. W.; Aiken, G. R.; Krabbenhoft, D. P.; Nagy, K. L.; Ryan, J. N.

    2008-12-01

    Mercury speciation and bioavailability is frequently thought to be controlled by the presence of dissolved organic matter (DOM) and sulfide. However, the speciation of mercury in these systems is poorly understood due to the complex interactions of mercury, DOM, and sulfide. We have developed a combined chromatographic-extended x-ray absorption fine structure (EXAFS) spectroscopy approach to determine the speciation of the hydrophobic fraction of mercury species in both sulfide-free and sulfide-rich (100 μM) experimental systems that also contain dissolved organic matter isolated from several locations, including the Florida Everglades. Chromatographic experiments were carried out with and without sulfide at varied mercury concentrations ranging from 0.1 nM to 1 μM in the presence of 10 mg L-1 DOM. The method consists of equilibrating the mercury-DOM with or without sulfide for 20 h (pH 6.5, I 0.1M) followed by chromatographic fractionation and concentration on a small column of C18 resin. Greater than 80% of the mercury in all solutions was found to be hydrophobic with respect to the resin when the mercury was interacting with the strong-binding DOM sites. The chromatographic behavior of solutions with and without sulfide was distinctly different. Sulfide-free mercury-DOM systems exhibited typical chromatographic behavior exemplified by resin saturation and subsequent breakthrough of mercury species. The sulfide-rich system exhibited very high resin affinity for almost all mercury species in solution and no apparent breakthrough, regardless of the ratio of mercury to DOM. Similar chromatographic experiments were carried out with and without sulfide at mercury concentrations as low as 250 nM and a DOM concentration of 50 mg L-1. EXAFS spectroscopy at the mercury LIII edge clearly showed spectra consistent with metacinnabar (HgS) as the dominant form of mercury adsorbed to the resin under sulfidic conditions despite the fact that no bulk precipitation was observed

  6. FUNDAMENTAL SCIENCE AND ENGINEERING OF MERCURY CONTROL IN COAL-FIRED POWER PLANTS

    Science.gov (United States)

    The paper discusses the existing knowledge base applicable to mercury (Hg) control in coal-fired boilers and outlines the gaps in knowledge that can be filled by experimentation and data gathering. Mercury can be controlled by existing air pollution control devices or by retrofit...

  7. Investigation of Processes Controlling Mercury Cycling at Midlatitudinal Marine and Inland Sites: Improvements and Applications of A Mercury Box Model

    Science.gov (United States)

    ye, Z.

    2013-12-01

    Mercury (Hg) is a hazardous pollutant due to the bioaccumulation in food chain. It is emitted to the atmosphere primarily as elemental form, and the long lifetime of which allows global transport. Oxidation of gaseous elemental mercury (GEM) generates reactive gaseous mercury (RGM) which plays an important role in the atmospheric mercury cycle by enhancing the rate of mercury deposition to ecosystem. The present study aimed to investigate the midlatitudinal atmospheric Hg cycling. To achieve that, a mercury chemistry box model was improved by employing the most up-to-date kinetic data for gaseous and aqueous reactions, and was applied to summertime clear sky conditions at three specific sites: Appledore Island (marine site), Thompson Farm (coastal site), and Pack Monadnock (inland site). The model was evaluated using observational data of RGM and pHg (particulate mercury) concentrations from these sites. The simulation results for all three sites showed that HgO, which is produced from oxidation of GEM by O3 and OH, contributed the most (>82%) to the total RGM production. Even in the marine boundary layer, halogen species (mainly Br) only contributed less than 12% to total RGM. The importance of reactions in most updated halogen chemistry has been evaluated. Gas and particle partitioning played an important role in coastal and inland environments. Some abnormally high RGM peaks were found at Appledore Island which may be explained by transport and air-sea exchange. Specific reactions and other processes controlling the diurnal cycles of RGM and pHg at the three sites are still being investigated.

  8. A mechanical, thermal and electrical packaging design for a prototype power management and control system for the 30 cm mercury ion thruster

    Science.gov (United States)

    Sharp, G. R.; Gedeon, L.; Oglebay, J. C.; Shaker, F. S.; Siegert, C. E.

    1978-01-01

    A prototype Electric Power Management and Thruster Control System for a 30 cm ion thruster has been built and is ready to support a first mission application. The system meets all of the requirements necessary to operate a thruster in a fully automatic mode. Power input to the system can vary over a full two to one dynamic range (200 to 400 V) for the solar array or other power source. The Power Management and Control system is designed to protect the thruster, the flight system and itself from arcs and is fully compatible with standard spacecraft electronics. The system is designed to be easily integrated into flight systems which can operate over a thermal environment ranging from 0.3 to 5 AU. The complete Power Management and Control system measures 45.7 cm x 15.2 cm x 114.8 cm and weighs 36.2 kg. At full power the overall efficiency of the system is estimated to be 87.4 percent. Three systems are currently being built and a full schedule of environmental and electrical testing is planned.

  9. A mechanical, thermal and electrical packaging design for a prototype power management and control system for the 30 cm mercury ion thruster

    Science.gov (United States)

    Sharp, G. R.; Gedeon, L.; Oglebay, J. C.; Shaker, F. S.; Siegert, C. E.

    1978-01-01

    A prototype electric power management and thruster control system for a 30 cm ion thruster is described. The system meets all of the requirements necessary to operate a thruster in a fully automatic mode. Power input to the system can vary over a full two to one dynamic range (200 to 400 V) for the solar array or other power source. The power management and control system is designed to protect the thruster, the flight system and itself from arcs and is fully compatible with standard spacecraft electronics. The system is easily integrated into flight systems which can operate over a thermal environment ranging from 0.3 to 5 AU. The complete power management and control system measures 45.7 cm (18 in.) x 15.2 cm (6 in.) x 114.8 cm (45.2 in.) and weighs 36.2 kg (79.7 lb). At full power the overall efficiency of the system is estimated to be 87.4 percent. Three systems are currently being built and a full schedule of environmental and electrical testing is planned.

  10. Full-Scale Testing of a Mercury Oxidation Catalyst Upstream of a Wet FGD System

    Energy Technology Data Exchange (ETDEWEB)

    Gary Blythe; Jennifer Paradis

    2010-06-30

    This document presents and discusses results from Cooperative Agreement DE-FC26-06NT42778, 'Full-scale Testing of a Mercury Oxidation Catalyst Upstream of a Wet FGD System,' which was conducted over the time-period July 24, 2006 through June 30, 2010. The objective of the project was to demonstrate at full scale the use of solid honeycomb catalysts to promote the oxidation of elemental mercury in pulverized-coal-fired flue gas. Oxidized mercury is removed downstream in wet flue gas desulfurization (FGD) absorbers and collected with the byproducts from the FGD system. The project was co-funded by EPRI, the Lower Colorado River Authority (LCRA), who also provided the host site, Great River Energy, Johnson Matthey, Southern Company, Salt River Project (SRP), the Tennessee Valley Authority (TVA), NRG Energy, Ontario Power and Westar. URS Group was the prime contractor and also provided cofunding. The scope of this project included installing and testing a gold-based catalyst upstream of one full-scale wet FGD absorber module (about 200-MW scale) at LCRA's Fayette Power Project (FPP) Unit 3, which fires Powder River Basin coal. Installation of the catalyst involved modifying the ductwork upstream of one of three wet FGD absorbers on Unit 3, Absorber C. The FGD system uses limestone reagent, operates with forced sulfite oxidation, and normally runs with two FGD modules in service and one spare. The full-scale catalyst test was planned for 24 months to provide catalyst life data. Over the test period, data were collected on catalyst pressure drop, elemental mercury oxidation across the catalyst module, and mercury capture by the downstream wet FGD absorber. The demonstration period began on May 6, 2008 with plans for the catalyst to remain in service until May 5, 2010. However, because of continual increases in pressure drop across the catalyst and concerns that further increases would adversely affect Unit 3 operations, LCRA decided to end the

  11. Subtask 4.8 - Fate and Control of Mercury and Trace Elements

    Energy Technology Data Exchange (ETDEWEB)

    Pavlish, John; Lentz, Nicholas; Martin, Christopher; Ralston, Nicholas; Zhuang, Ye; Hamre, Lucinda

    2011-12-31

    The Center for Air Toxic Metals® (CATM®) Program at the Energy & Environmental Research Center (EERC) continues to focus on vital basic and applied research related to the fate, behavior, measurement, and control of trace metals, especially mercury, and the impact that these trace metals have on human health and the environment. For years, the CATM Program has maintained an international perspective, performing research and providing results that apply to both domestic and international audiences, with reports distributed in the United States and abroad. In addition to trace metals, CATM’s research focuses on other related emissions and issues that impact trace metal releases to the environment, such as SOx, NOx, CO2, ash, and wastewater streams. Of paramount interest and focus has been performing research that continues to enable the power and industrial sectors to operate in an environmentally responsible manner to meet regulatory standards. The research funded by the U.S. Department of Energy’s (DOE’s) National Energy Technology Laboratory (NETL) through CATM has allowed significant strides to be made to gain a better understanding of trace metals and other emissions, improve sampling and measurement techniques, fill data gaps, address emerging technical issues, and develop/test control technologies that allow industry to cost-effectively meet regulatory standards. The DOE NETL–CATM research specifically focused on the fate and control of mercury and trace elements in power systems that use CO2 control technologies, such as oxycombustion and gasification systems, which are expected to be among those technologies that will be used to address climate change issues. In addition, research addressed data gaps for systems that use conventional and multipollutant control technologies, such as electrostatic precipitators, selective catalytic reduction units, flue gas desulfurization systems, and flue gas

  12. Development of novel activated carbon-based adsorbents for the control of mercury emissions from coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Radisav D. Vidic

    1999-03-01

    In addition to naturally occurring mercury sources, anthropogenic activities increase the mercury loading to the environment. Although not all produced mercury is dissipated directly into the environment, only minor portions of the total production are stocked or recycled, and the rest of the mercury and its compounds is finally released in some way into atmosphere, surface waters and soil, or ends in landfills dumps, and refuse. Since mercury and its compounds are highly toxic, their presence in the environment constitutes potential impact on all living organisms, including man. The first serious consequence of industrial mercury discharges causing neurological disorder even death occurred in Minimata, Japan in 1953. Systematic studies showed that mercury poisoning is mainly found in fish-eating populations. However, various levels of mercury are also found in food other than fish. During the past several decades, research has been conducted on the evaluation of risks due to exposure to mercury and the development of control technologies for mercury emissions. In 1990, the Clean Air Act Amendments listed mercury, along with 10 other metallic species, as a hazardous air pollutant (HAP). This has further stimulated research for mercury control during the past several years. The impact of mercury on humans, sources of mercury in the environment, current mercury control strategies and the objective of this research are discussed in this section.

  13. Controlling mercury spills in laboratories with a thermometer exchange program

    Energy Technology Data Exchange (ETDEWEB)

    McLouth, Lawrence D.

    2002-03-25

    This paper presents a case for replacing mercury thermometers with their organic-liquid-filled counterparts. A review of liquid-in glass-thermometers is given. In addition, a brief summary of mercury's health effects and exposure limits is presented. Spill cleanup methods and some lessons learned from our experience are offered as well. Finally, an overview of the mercury thermometer exchange program developed at Lawrence Berkeley National Laboratory is presented.

  14. Mission,System Design and Payload Aspects of ESA's Mercury Cornerstone Mission

    Science.gov (United States)

    Ferri, A.; Anselmi, A.; Scoon, G. E. N.

    1999-09-01

    Aim of this paper is to summarise the 1-year study performed by Alenia Aerospazio in close co-operation with the European Space Agency, on the Mercury Cornerstone System and Technology Study, as a part of Horizon 2000+ Scientific Programme plan. ESA's definition study towards a mission to Mercury conceives the launch of a S/C in 2009, on a two to three years journey, plus a one-year scientific observations and data take. The mission's primary objectives are manyfolded, aiming at approaching basic scientific questions on the origin and evolution of Mercury: identify and map the chemical and mineral composition of the surface, measure the topography of surface landforms, define the gravitational field, investigate particles and magnetic fields. The mission is also intended to resolve the librational state of the planet, in a system experiment requiring high accuracy inertial attitude (arcsecond level) and orbit (m-level) reconstitution. This experiment will allow to infer whether Mercury has a molten core, which is crucial to theories of magnetic field generation, and theories of the thermal history of terrestrial type planets. A hard-lander is planned to perform in-situ surface geochemical analysis. The mission is expected to provide scientists with a global portrait of Mercury returning about 1200 Gbits of scientific data, during a 1-year observation phase. The crucial aspects of the spacecraft design have to do with the high-temperature and high-radiation environment. Thermal control is achieved by a combination of orbit selection, attitude law, and special design provisions for IR shielding and HT insulation. Ad-hoc design provisions are envisaged for power and antenna mechanisms. Though the conceptual objectives of this industrial study focused on system architectures and enabling technologies for a "Cornerstone" class mission, in this paper emphasis is given on the scientific payload aspects.

  15. Mercury in terrestrial forested systems with highly elevated mercury deposition in southwestern China: The risk to insects and potential release from wildfires

    International Nuclear Information System (INIS)

    Zhou, Jun; Wang, Zhangwei; Sun, Ting; Zhang, Huan; Zhang, Xiaoshan

    2016-01-01

    Forests are considered a pool of mercury in the global mercury cycle. However, few studies have investigated the distribution of mercury in the forested systems in China. Tieshanping forest catchment in southwest China was impacted by mercury emissions from industrial activities and coal combustions. Our work studied mercury content in atmosphere, soil, vegetation and insect with a view to estimating the potential for mercury release during forest fires. Results of the present study showed that total gaseous mercury (TGM) was highly elevated and the annual mean concentration was 3.51 ± 1.39 ng m −2 . Of the vegetation tissues, the mercury concentration follows the order of leaf/needle > root > bark > branch > bole wood for each species. Total ecosystem mercury pool was 103.5 mg m −2 and about 99.4% of the mercury resides in soil layers (0–40 cm). The remaining 0.6% (0.50 mg m −2 ) of mercury was stored in biomass. The large mercury stocks in the forest ecosystem pose a serious threat for large pluses to the atmospheric mercury during potential wildfires and additional ecological stress to forest insect: dung beetles, cicada and longicorn, with mercury concentration of 1983 ± 446, 49 ± 38 and 7 ± 5 ng g −1 , respectively. Hence, the results obtained in the present study has implications for global estimates of mercury storage in forests, risks to forest insect and potential release to the atmosphere during wildfires. - Highlights: • Mercury in air, soil, biomass and insect were studied at a subtropical forest. • 99.4% of the total ecosystem mercury pools was resided in soil layers. • High mercury pools were large pulses to the atmosphere during potential wildfires. • High mercury deposition in forest pose an ecological stress to insect. - Large mercury pools in forest pose a serious threat for large pluses to the atmospheric mercury during potential wildfires and ecological stress to insect.

  16. Mercury in terrestrial forested systems with highly elevated mercury deposition in southwestern China: The risk to insects and potential release from wildfires.

    Science.gov (United States)

    Zhou, Jun; Wang, Zhangwei; Sun, Ting; Zhang, Huan; Zhang, Xiaoshan

    2016-05-01

    Forests are considered a pool of mercury in the global mercury cycle. However, few studies have investigated the distribution of mercury in the forested systems in China. Tieshanping forest catchment in southwest China was impacted by mercury emissions from industrial activities and coal combustions. Our work studied mercury content in atmosphere, soil, vegetation and insect with a view to estimating the potential for mercury release during forest fires. Results of the present study showed that total gaseous mercury (TGM) was highly elevated and the annual mean concentration was 3.51 ± 1.39 ng m(-2). Of the vegetation tissues, the mercury concentration follows the order of leaf/needle > root > bark > branch > bole wood for each species. Total ecosystem mercury pool was 103.5 mg m(-2) and about 99.4% of the mercury resides in soil layers (0-40 cm). The remaining 0.6% (0.50 mg m(-2)) of mercury was stored in biomass. The large mercury stocks in the forest ecosystem pose a serious threat for large pluses to the atmospheric mercury during potential wildfires and additional ecological stress to forest insect: dung beetles, cicada and longicorn, with mercury concentration of 1983 ± 446, 49 ± 38 and 7 ± 5 ng g(-1), respectively. Hence, the results obtained in the present study has implications for global estimates of mercury storage in forests, risks to forest insect and potential release to the atmosphere during wildfires. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Unified Science Information Model for SoilSCAPE using the Mercury Metadata Search System

    Science.gov (United States)

    Devarakonda, Ranjeet; Lu, Kefa; Palanisamy, Giri; Cook, Robert; Santhana Vannan, Suresh; Moghaddam, Mahta Clewley, Dan; Silva, Agnelo; Akbar, Ruzbeh

    2013-12-01

    SoilSCAPE (Soil moisture Sensing Controller And oPtimal Estimator) introduces a new concept for a smart wireless sensor web technology for optimal measurements of surface-to-depth profiles of soil moisture using in-situ sensors. The objective is to enable a guided and adaptive sampling strategy for the in-situ sensor network to meet the measurement validation objectives of spaceborne soil moisture sensors such as the Soil Moisture Active Passive (SMAP) mission. This work is being carried out at the University of Michigan, the Massachusetts Institute of Technology, University of Southern California, and Oak Ridge National Laboratory. At Oak Ridge National Laboratory we are using Mercury metadata search system [1] for building a Unified Information System for the SoilSCAPE project. This unified portal primarily comprises three key pieces: Distributed Search/Discovery; Data Collections and Integration; and Data Dissemination. Mercury, a Federally funded software for metadata harvesting, indexing, and searching would be used for this module. Soil moisture data sources identified as part of this activity such as SoilSCAPE and FLUXNET (in-situ sensors), AirMOSS (airborne retrieval), SMAP (spaceborne retrieval), and are being indexed and maintained by Mercury. Mercury would be the central repository of data sources for cal/val for soil moisture studies and would provide a mechanism to identify additional data sources. Relevant metadata from existing inventories such as ORNL DAAC, USGS Clearinghouse, ARM, NASA ECHO, GCMD etc. would be brought in to this soil-moisture data search/discovery module. The SoilSCAPE [2] metadata records will also be published in broader metadata repositories such as GCMD, data.gov. Mercury can be configured to provide a single portal to soil moisture information contained in disparate data management systems located anywhere on the Internet. Mercury is able to extract, metadata systematically from HTML pages or XML files using a variety of

  18. JV Task 126 - Mercury Control Technologies for Electric Utilities Burning Bituminous Coal

    Energy Technology Data Exchange (ETDEWEB)

    Jason Laumb; John Kay; Michael Jones; Brandon Pavlish; Nicholas Lentz; Donald McCollor; Kevin Galbreath

    2009-03-29

    The EERC developed an applied research consortium project to test cost-effective mercury (Hg) control technologies for utilities burning bituminous coals. The project goal was to test innovative Hg control technologies that have the potential to reduce Hg emissions from bituminous coal-fired power plants by {ge}90% at costs of one-half to three-quarters of current estimates for activated carbon injection (ACI). Hg control technology evaluations were performed using the EERC's combustion test facility (CTF). The CTF was fired on pulverized bituminous coals at 550,000 Btu/hr (580 MJ/hr). The CTF was configured with the following air pollution control devices (APCDs): selective catalytic reduction (SCR) unit, electrostatic precipitator (ESP), and wet flue gas desulfurization system (WFDS). The Hg control technologies investigated as part of this project included ACI (three Norit Americas, Inc., and eleven Envergex sorbents), elemental mercury (Hg{sup 0}) oxidation catalysts (i.e., the noble metals in Hitachi Zosen, Cormetech, and Hitachi SCR catalysts), sorbent enhancement additives (SEAs) (a proprietary EERC additive, trona, and limestone), and blending with a Powder River Basin (PRB) subbituminous coal. These Hg control technologies were evaluated separately, and many were also tested in combination.

  19. Radiological control for 203Hg radiotracer determinations of mercury inventories at chlor-alkali plants.

    Science.gov (United States)

    Martin, J E; Lee, C

    2001-11-01

    20Hg has been used safely to determine mercury inventories in large electrochemical process cells in the chlorine industry by a process of isotopic dilution. Laboratory conversion and processing of irradiated HgO can be done in closed systems with non-detectable releases to work areas or the environment and with exposure to whole body <0.25 mSv (25 mrem) and <3 mSv (300 mrem) to extremities. Personnel exposures during plant operations are controlled to non-detectable levels for whole body exposure and <0.3 mSv (30 mrem) to extremities for the operator; exposures for other plant personnel are non-detectable.

  20. Organic matter - A key factor in controlling mercury distribution in estuarine sediment

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Sarkar, A.; Vudamala, K.; Naik, R.; Nath, B.N.

    Organic matter (OM) was found to play an important role in controlling mercury (Hg) distribution and speciation in estuarine sediment of the Vembanad Lake. The sedimentary organic carbon (OC) from the northern part of the lake was influenced mainly...

  1. A Comparison of Urinary Mercury between Children with Autism Spectrum Disorders and Control Children

    Science.gov (United States)

    Wright, Barry; Pearce, Helen; Allgar, Victoria; Miles, Jeremy; Whitton, Clare; Leon, Irene; Jardine, Jenny; McCaffrey, Nicola; Smith, Rob; Holbrook, Ian; Lewis, John; Goodall, David; Alderson-Day, Ben

    2012-01-01

    Background Urinary mercury concentrations are used in research exploring mercury exposure. Some theorists have proposed that autism is caused by mercury toxicity. We set out to test whether mercury concentrations in the urine of children with autism were significantly increased or decreased compared to controls or siblings. Methods Blinded cohort analyses were carried out on the urine of 56 children with autism spectrum disorders (ASD) compared to their siblings (n = 42) and a control sample of children without ASD in mainstream (n = 121) and special schools (n = 34). Results There were no statistically significant differences in creatinine levels, in uncorrected urinary mercury levels or in levels of mercury corrected for creatinine, whether or not the analysis is controlled for age, gender and amalgam fillings. Conclusions This study lends no support for the hypothesis of differences in urinary mercury excretion in children with autism compared to other groups. Some of the results, however, do suggest further research in the area may be warranted to replicate this in a larger group and with clear measurement of potential confounding factors. PMID:22355303

  2. A comparison of urinary mercury between children with autism spectrum disorders and control children.

    Directory of Open Access Journals (Sweden)

    Barry Wright

    Full Text Available BACKGROUND: Urinary mercury concentrations are used in research exploring mercury exposure. Some theorists have proposed that autism is caused by mercury toxicity. We set out to test whether mercury concentrations in the urine of children with autism were significantly increased or decreased compared to controls or siblings. METHODS: Blinded cohort analyses were carried out on the urine of 56 children with autism spectrum disorders (ASD compared to their siblings (n = 42 and a control sample of children without ASD in mainstream (n = 121 and special schools (n = 34. RESULTS: There were no statistically significant differences in creatinine levels, in uncorrected urinary mercury levels or in levels of mercury corrected for creatinine, whether or not the analysis is controlled for age, gender and amalgam fillings. CONCLUSIONS: This study lends no support for the hypothesis of differences in urinary mercury excretion in children with autism compared to other groups. Some of the results, however, do suggest further research in the area may be warranted to replicate this in a larger group and with clear measurement of potential confounding factors.

  3. Quantification of Gaseous Elemental Mercury Dry Deposition to Environmental Surfaces using Mercury Stable Isotopes in a Controlled Environment

    Science.gov (United States)

    Rutter, A. P.; Schauer, J. J.; Shafer, M. M.; Olson, M.; Robinson, M.; Vanderveer, P.; Creswell, J. E.; Parman, A.; Mallek, J.; Gorski, P.

    2009-12-01

    Andrew P. Rutter (1) * *, James J, Schauer (1,2) *, Martin M. Shafer(1,2), Michael R. Olson (1), Michael Robinson (1), Peter Vanderveer (3), Joel Creswell (1), Justin L. Mallek (1), Andrew M. Parman (1) (1) Environmental Chemistry and Technology Program, 660 N. Park St, Madison, WI 53705. (2) Wisconsin State Laboratory of Hygiene, 2601 Agriculture Drive, Madison, WI 53718. (3) Biotron, University of Wisconsin - Madison, 2115 Observatory Drive, Madison, WI 53706 * Correspond author(jjschauer@wisc.edu) * *Presenting author (aprutter@wisc.edu) Abstract Gaseous elemental mercury (GEM) is the predominant component of atmospheric mercury outside of arctic depletion events, and locations where anthropogenic point sources are not influencing atmospheric concentrations. GEM constitutes greater than 99% of the mercury mass in most rural and remote locations. While dry and wet deposition of atmospheric mercury is thought to be dominated by oxidized mercury (a.k.a. reactive mercury), only small GEM uptake to environmental surfaces could impact the input of mercury to terrestrial and aquatic ecosystems. Dry deposition and subsequent re-emission of gaseous elemental mercury is a pathway from the atmosphere that remains only partially understood from a mechanistic perspective. In order to properly model GEM dry deposition and re-emission an understanding of its dependence on irradiance, temperature, and relative humidity must be measured and parameterized for a broad spectrum of environmental surfaces colocated with surrogate deposition surfaces used to make field based dry deposition measurements. Measurements of isotopically enriched GEM dry deposition were made with a variety of environmental surfaces in a controlled environment room at the University of Wisconsin Biotron. The experimental set up allowed dry deposition components which are not easily separated in the field to be decoupled. We were able to isolate surface transfer processes from variabilities caused by

  4. Mercury Exposure and Heart Diseases.

    Science.gov (United States)

    Genchi, Giuseppe; Sinicropi, Maria Stefania; Carocci, Alessia; Lauria, Graziantonio; Catalano, Alessia

    2017-01-12

    Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

  5. Mercury Exposure and Heart Diseases

    Directory of Open Access Journals (Sweden)

    Giuseppe Genchi

    2017-01-01

    Full Text Available Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.

  6. Quantitative evaluation of environmental factors influencing the dynamics of mercury in the aquatic systems

    International Nuclear Information System (INIS)

    Akagi, H.; Sakamoto, M.

    2001-01-01

    A highly sensitive radiochemical technique for evaluating the transformation and distribution of mercury has been developed to facilitate studies on the kinetics of mercury in the aquatic systems. Sediment, water, or biota, previously spiked with 203-mercuric compounds and incubated for a few or several weeks, are extracted with 0.1% dithizone-benzene(Dz-Bz) after an appropriate pretreatment to dissolve the incorporated mercury compounds. The quantitative separation of inorganic mercury and methylmercury in the Dz-Bz extract is done by thin-layer chromatography, before the mercury species are analyzed radiometrically using a gamma counter. The technique is applicable to a wide range of environmental materials contaminated with mercury down to very low background concentrations. (author)

  7. Sorbent Injection for Small ESP Mercury Control in Low Sulfur Eastern Bituminous Coal Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Carl Richardson; Katherine Dombrowski; Douglas Orr

    2006-12-31

    This project Final Report is submitted to the U.S. Department of Energy (DOE) as part of Cooperative Agreement DE-FC26-03NT41987, 'Sorbent Injection for Small ESP Mercury Control in Low Sulfur Eastern Bituminous Coal Flue Gas.' Sorbent injection technology is targeted as the primary mercury control process on plants burning low/medium sulfur bituminous coals equipped with ESP and ESP/FGD systems. About 70% of the ESPs used in the utility industry have SCAs less than 300 ft2/1000 acfm. Prior to this test program, previous sorbent injection tests had focused on large-SCA ESPs. This DOE-NETL program was designed to generate data to evaluate the performance and economic feasibility of sorbent injection for mercury control at power plants that fire bituminous coal and are configured with small-sized electrostatic precipitators and/or an ESP-flue gas desulfurization (FGD) configuration. EPRI and Southern Company were co-funders for the test program. Southern Company and Reliant Energy provided host sites for testing and technical input to the project. URS Group was the prime contractor to NETL. ADA-ES and Apogee Scientific Inc. were sub-contractors to URS and was responsible for all aspects of the sorbent injection systems design, installation and operation at the different host sites. Full-scale sorbent injection for mercury control was evaluated at three sites: Georgia Power's Plant Yates Units 1 and 2 [Georgia Power is a subsidiary of the Southern Company] and Reliant Energy's Shawville Unit 3. Georgia Power's Plant Yates Unit 1 has an existing small-SCA cold-side ESP followed by a Chiyoda CT-121 wet scrubber. Yates Unit 2 is also equipped with a small-SCA ESP and a dual flue gas conditioning system. Unit 2 has no SO2 control system. Shawville Unit 3 is equipped with two small-SCA cold-side ESPs operated in series. All ESP systems tested in this program had SCAs less than 250 ft2/1000 acfm. Short-term parametric tests were conducted on Yates

  8. Subcellular controls of mercury trophic transfer to a marine fish

    International Nuclear Information System (INIS)

    Dang Fei; Wang Wenxiong

    2010-01-01

    Different behaviors of inorganic mercury [Hg(II)] and methylmercury (MeHg) during trophic transfer along the marine food chain have been widely reported, but the mechanisms are not fully understood. The bioavailability of ingested mercury, quantified by assimilation efficiency (AE), was investigated in a marine fish, the grunt Terapon jarbua, based on mercury subcellular partitioning in prey and purified subcellular fractions of prey tissues. The subcellular distribution of Hg(II) differed substantially among prey types, with cellular debris being a major (49-57% in bivalves) or secondary (14-19% in other prey) binding pool. However, MeHg distribution varied little among prey types, with most MeHg (43-79%) in heat-stable protein (HSP) fraction. The greater AEs measured for MeHg (90-94%) than for Hg(II) (23-43%) confirmed the findings of previous studies. Bioavailability of each purified subcellular fraction rather than the proposed trophically available metal (TAM) fraction could better elucidate mercury assimilation difference. Hg(II) associated with insoluble fraction (e.g. cellular debris) was less bioavailable than that in soluble fraction (e.g. HSP). However, subcellular distribution was shown to be less important for MeHg, with each fraction having comparable MeHg bioavailability. Subcellular distribution in prey should be an important consideration in mercury trophic transfer studies.

  9. MERCURY IN FISHERY PRODUCTS FROM CENTRAL ADRIATIC SEA (OFFICIAL CONTROLS FROM 1995 TO 2009

    Directory of Open Access Journals (Sweden)

    C. Ciccarelli

    2011-04-01

    Full Text Available Thanks to its properties, methylmercury is the most bioavailable form of mercury compounds. In fact, it causes the most toxic effects on the immune, cardiovascular, renal and central nervous systems, in particular the fetal brain. Seafood consumption is recognized as being the largest environmental mercury source to most human populations. So, fishery products are the most important source of methylmercury exposure in human. As the mercury burden of fish increases for transference to upper trophic levels (biomagnification, piscivors have the potential to accumulate extremely high mercury loads, in the methylated form, 70 to 100% in the muscular tissues. Reg. CE 1881/2006 sets, lastly, allowed maximum levels of mercury in seafood. Several authors found out an increase of mercury levels with size of carnivorous fishes. But this relationship strictly depends on fish species, and is a result of the interaction between environmental and physiological effects. This paper describes the results of a monitoring of mercury levels in fishery products, from 1995 to 2009, before they were sold by auction in the Wholesale Fish Market in the town of San Benedetto del Tronto. The authors’aim was to set a correlation between increasing fish size (weight and loads of the metal up to maximum levels by law.

  10. Anatomical Mercury: Changing Understandings of Quicksilver, Blood, and the Lymphatic System, 1650-1800.

    Science.gov (United States)

    Hendriksen, Marieke M A

    2015-10-01

    The use of mercury as an injection mass in anatomical experiments and preparations was common throughout Europe in the long eighteenth century, and refined mercury-injected preparations as well as plates of anatomical mercury remain today. The use and meaning of mercury in related disciplines such as medicine and chemistry in the same period have been studied, but our knowledge of anatomical mercury is sparse and tends to focus on technicalities. This article argues that mercury had a distinct meaning in anatomy, which was initially influenced by alchemical and classical understandings of mercury. Moreover, it demonstrates that the choice of mercury as an anatomical injection mass was deliberate and informed by an intricate cultural understanding of its materiality, and that its use in anatomical preparations and its perception as an anatomical material evolved with the understanding of the circulatory and lymphatic systems. By using the material culture of anatomical mercury as a starting point, I seek to provide a new, object-driven interpretation of complex and strongly interrelated historiographical categories such as mechanism, vitalism, chemistry, anatomy, and physiology, which are difficult to understand through a historiography that focuses exclusively on ideas. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Mockup experiments to investigate the leak rate correlation between mercury and helium for the mercury target system of J-PARC

    International Nuclear Information System (INIS)

    Haga, Katsuhiro; Naoe, Takashi; Kogawa, Hiroyuki; Wakui, Takashi; Futakawa, Masatoshi

    2009-01-01

    Checking the seal performance of the mercury piping network is very important for the mercury target system operation of J-PARC, and the test method for leaks using the pressure change measurement is preferable for this purpose because it can be carried out easily and precisely by measuring the pressure change, and it is free from the risk of mercury contamination. The piping network is pressurized by helium gas. Thus, the correlation between the helium leak rate and mercury leak flow rate was investigated experimentally by carrying out leak tests for helium and mercury with an identical mockup flange model. The results showed that the mercury leak flow rates of the experimental data were lower than those of the estimated value by 64% on average. It was also found that the threshold of the helium leak rate at which good seal performance for mercury can be obtained exists between 2.18 x 10 -4 and 1.01 x 10 -2 Pa.m 3 /s. This fact confirmed the sufficient safety margin of the mercury target system against the mercury leak, where 1 x 10 -6 Pa.m 3 /s was adopted as the seal performance criterion. (author)

  12. Phytoremediation of Ionic and Methyl Mercury Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2005-06-01

    Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems. Our current strategy is to engineer plants to

  13. Toxic Effects of Mercury on the Cardiovascular and Central Nervous Systems

    Directory of Open Access Journals (Sweden)

    Bruna Fernandes Azevedo

    2012-01-01

    Full Text Available Environmental contamination has exposed humans to various metal agents, including mercury. This exposure is more common than expected, and the health consequences of such exposure remain unclear. For many years, mercury was used in a wide variety of human activities, and now, exposure to this metal from both natural and artificial sources is significantly increasing. Many studies show that high exposure to mercury induces changes in the central nervous system, potentially resulting in irritability, fatigue, behavioral changes, tremors, headaches, hearing and cognitive loss, dysarthria, incoordination, hallucinations, and death. In the cardiovascular system, mercury induces hypertension in humans and animals that has wide-ranging consequences, including alterations in endothelial function. The results described in this paper indicate that mercury exposure, even at low doses, affects endothelial and cardiovascular function. As a result, the reference values defining the limits for the absence of danger should be reduced.

  14. Toxic Effects of Mercury on the Cardiovascular and Central Nervous Systems

    Science.gov (United States)

    Fernandes Azevedo, Bruna; Barros Furieri, Lorena; Peçanha, Franck Maciel; Wiggers, Giulia Alessandra; Frizera Vassallo, Paula; Ronacher Simões, Maylla; Fiorim, Jonaina; Rossi de Batista, Priscila; Fioresi, Mirian; Rossoni, Luciana; Stefanon, Ivanita; Alonso, María Jesus; Salaices, Mercedes; Valentim Vassallo, Dalton

    2012-01-01

    Environmental contamination has exposed humans to various metal agents, including mercury. This exposure is more common than expected, and the health consequences of such exposure remain unclear. For many years, mercury was used in a wide variety of human activities, and now, exposure to this metal from both natural and artificial sources is significantly increasing. Many studies show that high exposure to mercury induces changes in the central nervous system, potentially resulting in irritability, fatigue, behavioral changes, tremors, headaches, hearing and cognitive loss, dysarthria, incoordination, hallucinations, and death. In the cardiovascular system, mercury induces hypertension in humans and animals that has wide-ranging consequences, including alterations in endothelial function. The results described in this paper indicate that mercury exposure, even at low doses, affects endothelial and cardiovascular function. As a result, the reference values defining the limits for the absence of danger should be reduced. PMID:22811600

  15. Engineering report for the central mercury treatment system

    International Nuclear Information System (INIS)

    1995-03-01

    Mercury (Hg) was used at the Oak Ridge Y-12 Plant between 1950 and 1963. This contamination legacy has prompted a series of remedial measures. Since the mid-1980s, a series of engineered projects, maintenance activities, and general improvement in work practices has resulted in a decreasing trend of Hg concentration in East Fork Poplar Creek (EFPC). Some of the Hg in the soils surrounding past Hg- use buildings enters the building sumps which are discharged to EFPC. Overall goal is to reduce the Hg contamination of EFPC to no more than 5 g/day. This project will create the Central Mercy Treatment System to reduce the Hg contribution to EFPC by installing carbon adsorption units to treat the effluent from buildings 9201-4, 9201-5, and 9204-4. Use of carbon adsorption will be the long-term strategy for reduction of Hg in plant effluent

  16. JV Task 122 - Assessment of Mercury Control Options for the San Miguel Electric Cooperative Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas Lentz; Brandon Pavlish; John Kay; Michael Jones

    2009-02-01

    In the United States, testing has been under way at electric coal-fired power plants to find viable and economical mercury control strategies to meet pending regulations. San Miguel Electric Cooperative (SMEC) engaged the Energy & Environmental Research Center (EERC) through a request for proposal (RFP) to perform research tests to evaluate sorbent-based technologies at its coal-fired San Miguel Generating Station to identify possible technology options that could be used by SMEC to meet the mercury reduction requirements of future U.S. federal standards. The goal of the testing was to target a mercury removal of {ge}90%. The EERC has successfully field-tested several sorbent-based technologies in previous projects that offer promise and potential to achieve a target removal of {ge}90%. Based on these field test results, yet recognizing that fuel type and plant operating conditions affect mercury capture significantly, the EERC proposed research tests to evaluate potential sorbent-based technologies provided by Norit Americas and the EERC that could potentially meet SMEC's mercury control objectives. Over the period of May through mid-June 2008, the EERC tested injection of both treated and nontreated activated carbon (AC) provided by Norit Americas and sorbent enhancement additives (SEAs) provided by the EERC. Tests were performed at San Miguel Unit 1 (450 MW) and included injection at the inlet of the air heater (AH) (temperature of 720 F). The test coal was a Texas lignite fuel with an average moisture content of 31.19%, an ash content of 26.6%, a heating value of 5,094 Btu/lb, a sulfur content of 2.7%, and a mercury concentration of 0.182 ppm, all reported on an as-received basis. Pilot-scale testing results identified DARCO{reg_sign} Hg-LH, SEA2 + DARCO{reg_sign} Hg, and the ChemMod sorbents as technologies with the potential to achieve the target mercury removal of {ge}90% at the full-scale test. Mercury concentrations were tracked with continuous

  17. Psychological effects of low exposure to mercury vapor: Application of a computer-administered neurobehavioral evaluation system

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Youxin; Sun, Rongkun; Sun, Yu; Chen, Ziqiang; Li, Linhong (Shanghai Medical Univ. (China))

    1993-02-01

    A computer-administered neurobehavioral evaluation system in a Chinese language version (NES-C) and a mood inventory of the profile of mood states (POMS) were applied to assess the psychological effects of low-level exposure to mercury vapor in a group of 88 workers (19 males and 69 females, with mean age of 34.2 years) exposed to mercury vapor (average duration of exposure 10.4 years). The well-matched group of 97 nonexposed workers was treated as the control. The intensity of current mercury vapor was relatively mild as reflected by the average level of mercury in the air of the workplace (0.033 mg/m[sup 3]) and in urine (0.025 mg/liter). The results indicated that the profile of mood states posed was moving to the negative side in Hg-exposed group and most of the NES-C performances, in particular, the mental arithmetic, two-digit search, switching attention, visual choice reaction time, and finger tapping, were also significantly affected compared with those obtained from controls (P < 0.05-0.01). The present study and the previous study on the validation of the system suggest that the NES-C we developed is valid for the neurotoxicity screening among the working population exposed to neurotoxic agents. 16 refs., 6 tabs.

  18. Cavity ring-down spectroscopy (CRDS) system for measuring atmospheric mercury using differential absorption

    Science.gov (United States)

    Pierce, A.; Obrist, D.; Moosmuller, H.; Moore, C.

    2012-04-01

    different efficiencies of laser performance (e.g., frequency doubling) at the two wavelengths and temperature dependence. We will discuss improvements on the control of our system to eliminate drift due to conversion efficiency and temperature dependence. We will detail complications with operating this instrument from a mobile platform for in situ measurements in the field. Finally, we will present data acquisition and processing approaches along with results of calibration curves, and comparisons to conventional mercury analyzers (i.e., a Tekran 2537 mercury vapor analyzer) during ambient air measurements.

  19. PERFORMANCE AND COST OF MERCURY AND MULTIPOLLUTANT EMISSION CONTROL TECHNOLOGY APPLICATIONS ON ELECTRIC UTILITY BOILERS

    Science.gov (United States)

    The report presents estimates of the performance and cost of both powdered activated carbon (PAC) and multipollutant control technologies that may be useful in controlling mercury emissions. Based on currently available data, cost estimates for PAC injection range are 0.03-3.096 ...

  20. A Spatial Data Infrastructure for the Global Mercury Observation System

    Directory of Open Access Journals (Sweden)

    Cinnirella S.

    2013-04-01

    Full Text Available The Global Mercury Observation System (GMOS Project includes a specific Work Package aimed at developing tools (i.e. databases, catalogs, services to collect GMOS datasets, harvest mercury databases, and offer services like search, view, and download spatial datasets from the GMOS portal (www.gmos.eu. The system will be developed under the framework of the Infrastructure for Spatial Information in the European Community (INSPIRE Directive and the Directive 2003/4/EC on public access to environmental information, which both aim to make relevant, harmonized, high-quality geographic information available to support the formulation, implementation, monitoring, and evaluation of policies and activities that have a direct or indirect impact on the environment. Three databases have been proposed (on emissions, field data and model results, and each will be equipped with state-of-the-art, open-source software to allow for the highest performance possible. Web-based user-interfaces and prototype applications will be developed to demonstrate the potential of blending different datasets from different servers for environmental assessment studies. Several services (i.e. catalog browsers, WMS and WCS services, web GIS services will be developed to facilitate data integration, data re-use, and data exchange within and beyond the GMOS project. Different types of measurement and model datasets provided by project partners and other sources will be integrated into PostgreSQL-PostGIS, harmonized by creating INSPIRE-compliant metadata and made available to a larger community of stakeholders, policy makers, scientists, and NGOs (as well as to other public and private institutions, as dictated by the Directive 2003/4/EC. Since interoperability is a central concept for the Global Earth Observation System of Systems (GEOSS, the Global Monitoring for Environmental and Security (GMES and the INSPIRE Directive, guidelines developed in these three frameworks will be

  1. An integrated systems-based approach to mercury research and technology development

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Mark J [ORNL; Brooks, Scott C [ORNL; Mathews, Teresa J [ORNL; Mayes, Melanie [ORNL; Watson, David B [ORNL; Johs, Alexander [ORNL; Mehlhorn, Tonia L [ORNL; Dickson, Johnbull O [ORNL; Mansfield, Charles [East Tennessee Technology Park (ETTP); Phillips, Elizabeth [U.S. Department of Energy (DOE); Pierce, Eric M [ORNL

    2017-01-01

    A 3-year strategic planning process was undertaken in Oak Ridge, Tennessee, to develop a research and technology development approach that can help guide mercury remediation in East Fork Poplar Creek (EFPC). Mercury remediation is a high priority for the US Department of Energy s (DOE s) Oak Ridge Office of Environmental Management because of large historical losses of mercury to the environment at the Y-12 National Security Complex (Y-12). Because of the extent of mercury losses and the complexities of mercury transport and fate in the stream environment, the success of conventional options for mercury remediation in the downstream sections of EFPC is uncertain. The overall Oak Ridge mercury remediation strategy focuses on mercury treatment actions at Y-12 in the short-term and research and technology development to evaluate longer-term solutions in the downstream environment. The technology development strategy is consistent with a phased, adaptive management paradigm and DOE s Technology Readiness Level guidelines. That is, early evaluation includes literature review, site characterization, and small-scale studies of a broad number of potential technologies. As more information is gathered, technologies that may have the most promise and potential remediation benefit will be chosen for more extensive and larger-scale pilot testing before being considered for remedial implementation. Field and laboratory research in EFPC is providing an improved level of understanding of mercury transport and fate processes in EFPC that will inform the development of site-specific remedial technologies. Technology development has centered on developing strategies that can mitigate the primary factors affecting mercury risks in the stream: (1) the amount of inorganic mercury available to the stream system, (2) the conversion of inorganic mercury to methylmercury, and (3) the bioaccumulation of methylmercury through the food web. Given the downstream complexities and

  2. Global Mercury Observation System (GMOS) surface observation data.

    Data.gov (United States)

    U.S. Environmental Protection Agency — GMOS global surface elemental mercury (Hg0) observations from 2013 & 2014. This dataset is associated with the following publication: Sprovieri, F., N. Pirrone,...

  3. Calls to Florida Poison Control Centers about mercury: Trends over 2003-2013.

    Science.gov (United States)

    Gribble, Matthew O; Deshpande, Aniruddha; Stephan, Wendy B; Hunter, Candis M; Weisman, Richard S

    2017-11-01

    The aim of this analysis was to contrast trends in exposure-report calls and informational queries (a measure of public interest) about mercury to the Florida Poison Control Centers over 2003-2013. Poison-control specialists coded calls to Florida Poison Control Centers by substance of concern, caller demographics, and whether the call pertained to an exposure event or was an informational query. For the present study, call records regarding mercury were de-identified and provided along with daily total number of calls for statistical analysis. We fit Poisson models using generalized estimating equations to summarize changes across years in counts of daily calls to Florida Poison Control Centers, adjusting for month. In a second stage of analysis, we further adjusted for the total number of calls each day. We also conducted analyses stratified by age of the exposed. There was an overall decrease over 2003-2013 in the number of total calls about mercury [Ratio per year: 0.89, 95% CI: (0.88, 0.90)], and calls about mercury exposure [Ratio per year: 0.84, 95% CI: (0.83, 0.85)], but the number of informational queries about mercury increased over this time [Ratio per year: 1.15 (95% CI: 1.12, 1.18)]. After adjusting for the number of calls of that type each day (e.g., call volume), the associations remained similar: a ratio of 0.88 (95% CI: 0.87, 0.89) per year for total calls, 0.85 (0.83, 0.86) for exposure-related calls, and 1.17 (1.14, 1.21) for informational queries. Although, the number of exposure-related calls decreased, informational queries increased over 2003-2013. This might suggest an increased public interest in mercury health risks despite a decrease in reported exposures over this time period. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Impact of wildfire on levels of mercury in forested watershed systems - Voyageurs National Park, Minnesota

    Science.gov (United States)

    Woodruff, Laurel G.; Sandheinrich, Mark B.; Brigham, Mark E.; Cannon, William F.

    2009-01-01

    disturbance, especially the historic forest fire pattern (Woodruff and Cannon, 2002). Forest fire has an essential role in the forest ecosystems of VNP (Heinselman, 1996). Because resource and land managers need to integrate both natural wildfire and prescribed fire in management plans, the potential influence of fire on an element as sensitive to the environment as mercury becomes a critical part of their decisionmaking. A number of recent studies have shown that while fire does have a significant impact on mercury at the landscape level, the observed effects of fire on aquatic environments are highly variable and unpredictable (Caldwell and others, 2000; Garcia and Carrigan, 2000; Kelly and others, 2006; Nelson and others, 2007). Caldwell and others (2000) described an increase in methylmercury in reservoir sediments resulting from mobilization and transport of charred vegetative matter following a fire in New Mexico. Krabbenhoft and Fink (2000) attributed increases in total mercury concentrations in young-of-the-year fish in the Florida Everglades to release of mercury resulting from peat oxidation following fires. A fivefold increase in whole-body mercury accumulation by rainbow trout (Oncorhynchus mykiss) following a fire in Alberta, Canada, apparently resulted from increased nutrient concentrations that enhanced productivity and restructured the food web of a lake within the fire's burn footprint (Kelly and others, 2006). For this study, we determined the short-term effects of forest fire on mercury concentrations in terrestrial and aquatic environments in VNP by comparing and contrasting mercury concentrations in forest soils, lake waters, and age-1 yellow perch for a burned watershed and an adjacent lake, with similar samples from watersheds and lakes with no fire activity (control watersheds and lakes). The concentration of total mercury in whole, 1-year-old yellow perch serves as a good biological indicator for monitoring trends in methylmercury conce

  5. Hypersonic MHD Propulsion System Integration for the Mercury Lightcraft

    International Nuclear Information System (INIS)

    Myrabo, L.N.; Rosa, R.J.

    2004-01-01

    Introduced herein are the design, systems integration, and performance analysis of an exotic magnetohydrodynamic (MHD) slipstream accelerator engine for a single-occupant 'Mercury' lightcraft. This ultra-energetic, laser-boosted vehicle is designed to ride a 'tractor beam' into space, transmitted from a future orbital network of satellite solar power stations. The lightcraft's airbreathing combined-cycle engine employs a rotary pulsed detonation thruster mode for lift-off and landing, and an MHD slipstream accelerator mode at hypersonic speeds. The latter engine transforms the transatmospheric acceleration path into a virtual electromagnetic 'mass-driver' channel; the hypersonic momentum exchange process (with the atmosphere) enables engine specific impulses in the range of 6000 to 16,000 seconds, and propellant mass fractions as low as 10%. The single-stage-to-orbit, highly reusable lightcraft can accelerate at 3 Gs into low Earth orbit with its throttle just barely beyond 'idle' power, or virtually 'disappear' at 30 G's and beyond. The objective of this advanced lightcraft design is to lay the technological foundations for a safe, very low cost (e.g., 1000X below chemical rockets) air and space transportation for human life in the mid-21st Century - a system that will be completely 'green' and independent of Earth's limited fossil fuel reserves

  6. Hypersonic MHD Propulsion System Integration for the Mercury Lightcraft

    Science.gov (United States)

    Myrabo, L. N.; Rosa, R. J.

    2004-03-01

    Introduced herein are the design, systems integration, and performance analysis of an exotic magnetohydrodynamic (MHD) slipstream accelerator engine for a single-occupant ``Mercury'' lightcraft. This ultra-energetic, laser-boosted vehicle is designed to ride a `tractor beam' into space, transmitted from a future orbital network of satellite solar power stations. The lightcraft's airbreathing combined-cycle engine employs a rotary pulsed detonation thruster mode for lift-off & landing, and an MHD slipstream accelerator mode at hypersonic speeds. The latter engine transforms the transatmospheric acceleration path into a virtual electromagnetic `mass-driver' channel; the hypersonic momentum exchange process (with the atmosphere) enables engine specific impulses in the range of 6000 to 16,000 seconds, and propellant mass fractions as low as 10%. The single-stage-to-orbit, highly reusable lightcraft can accelerate at 3 Gs into low Earth orbit with its throttle just barely beyond `idle' power, or virtually `disappear' at 30 G's and beyond. The objective of this advanced lightcraft design is to lay the technological foundations for a safe, very low cost (e.g., 1000X below chemical rockets) air and space transportation for human life in the mid-21st Century - a system that will be completely `green' and independent of Earth's limited fossil fuel reserves.

  7. Electrical Investigation of Metal-Olivine Systems and Application to the Deep Interior of Mercury

    Science.gov (United States)

    Zhang, Zhou; Pommier, Anne

    2017-12-01

    We report electrical conductivity measurements on metal-olivine systems at about 5 and 6 GPa and up to 1,675°C in order to investigate the electrical properties of core-mantle boundary (CMB) systems. Electrical experiments were conducted in the multianvil apparatus using the impedance spectroscopy technique. The samples are composed of one metal layer (Fe, FeS, FeSi2, or Fe-Ni-S-Si) and one polycrystalline olivine layer, with the metal:olivine ratio ranging from 1:0.7 to 1:9.2. For all samples, we observe that the bulk electrical conductivity increases with temperature from 10-2.5 to 101.8 S/m, which is higher than the conductivity of polycrystalline olivine but lower than the conductivity of the pure metal phase at similar conditions. In some experiments, a conductivity jump is observed at the temperature corresponding to the melting temperature of the metallic phase. Both the metal:olivine ratio and the metal phase geometry control the electrical conductivity of the two-layer samples. By combining electrical results, textural analyses of the samples, and previous studies of the structure and composition of Mercury's interior, we propose an electrical profile of the deep interior of the planet that accounts for a layered CMB-outer core structure. The electrical model agrees with existing conductivity estimates of Mercury's lower mantle and CMB using magnetic observations and thermodynamic calculations, and thus, supports the hypothesis of a layered CMB-outermost core structure in the present-day interior of Mercury. We propose that the layered CMB-outer core structure is possibly electrically insulating, which may influence the planet's structure and cooling history.

  8. CONTROL SYSTEM

    Science.gov (United States)

    Shannon, R.H.; Williamson, H.E.

    1962-10-30

    A boiling water type nuclear reactor power system having improved means of control is described. These means include provisions for either heating the coolant-moderator prior to entry into the reactor or shunting the coolantmoderator around the heating means in response to the demand from the heat engine. These provisions are in addition to means for withdrawing the control rods from the reactor. (AEC)

  9. The dosage of mercury vapours in air. Application to an atmospheric control

    International Nuclear Information System (INIS)

    Francois, H.; Vettier, M.C.; Moser, Y.

    1961-01-01

    The authors have studied a technique making it possible to trap completely the mercury vapours in the atmosphere and to analyse them with precision; their object is an application to an atmospheric control. The analytical method used is particularly sensitive and makes possible the determination of 1 micro-gram of mercury in a 1000 litre sample of air with an accuracy of 2 per cent. The total time for the operation can be estimated to be about 2 1/2 hours, including the analysis. The operations are straightforward and can be carried out by specialised personnel after a short training. (author) [fr

  10. CONTROL OF MERCURY EMISSIONS FROM COAL-FIRED ELECTRIC UTILITY BOILERS: INTERIM REPORT

    Science.gov (United States)

    The report provides additional information on mercury (Hg) emissions control following the release of "Study of Hazardous Air Pollutant Emissions from Electric Utility Steam Generating Units--Final Report to Congress" in February 1998. Chapters 1-3 describe EPA's December 2000 de...

  11. EMISSION TEST REPORT, OMSS FIELD TEST ON CARBON INJECTION FOR MERCURY CONTROL

    Science.gov (United States)

    The report discusses results of a parametric evaluation of powdered activated carbon for control of mercury (Hg) emission from a municipal waste cornbustor (MWC) equipped with a lime spray dryer absorber/fabric filter (SD/FF). The primary test objectives were to evaluate the effe...

  12. Calibration, Projection, and Final Image Products of MESSENGER's Mercury Dual Imaging System

    Science.gov (United States)

    Denevi, Brett W.; Chabot, Nancy L.; Murchie, Scott L.; Becker, Kris J.; Blewett, David T.; Domingue, Deborah L.; Ernst, Carolyn M.; Hash, Christopher D.; Hawkins, S. Edward; Keller, Mary R.; Laslo, Nori R.; Nair, Hari; Robinson, Mark S.; Seelos, Frank P.; Stephens, Grant K.; Turner, F. Scott; Solomon, Sean C.

    2018-02-01

    We present an overview of the operations, calibration, geodetic control, photometric standardization, and processing of images from the Mercury Dual Imaging System (MDIS) acquired during the orbital phase of the MESSENGER spacecraft's mission at Mercury (18 March 2011-30 April 2015). We also provide a summary of all of the MDIS products that are available in NASA's Planetary Data System (PDS). Updates to the radiometric calibration included slight modification of the frame-transfer smear correction, updates to the flat fields of some wide-angle camera (WAC) filters, a new model for the temperature dependence of narrow-angle camera (NAC) and WAC sensitivity, and an empirical correction for temporal changes in WAC responsivity. Further, efforts to characterize scattered light in the WAC system are described, along with a mosaic-dependent correction for scattered light that was derived for two regional mosaics. Updates to the geometric calibration focused on the focal lengths and distortions of the NAC and all WAC filters, NAC-WAC alignment, and calibration of the MDIS pivot angle and base. Additionally, two control networks were derived so that the majority of MDIS images can be co-registered with sub-pixel accuracy; the larger of the two control networks was also used to create a global digital elevation model. Finally, we describe the image processing and photometric standardization parameters used in the creation of the MDIS advanced products in the PDS, which include seven large-scale mosaics, numerous targeted local mosaics, and a set of digital elevation models ranging in scale from local to global.

  13. Mercury in Aquatic Systems of the Gulf Islands National Seashore ...

    African Journals Online (AJOL)

    This study reports on levels and speciation of mercury (Hg) in different environmental compartments of selected park units in the Gulf Islands National Seashore (USA), and on potential rates of methyl-Hg (MMHg) formation and degradation in sediments. In the aqueous phase, total (THg) and MMHg concentrations ranged ...

  14. Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems.

    Science.gov (United States)

    Lithwick, Yoram; Wu, Yanqin

    2014-09-02

    In the inner solar system, the planets' orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations.

  15. Dental devices: classification of dental amalgam, reclassification of dental mercury, designation of special controls for dental amalgam, mercury, and amalgam alloy; technical amendment. Final rule; technical amendment.

    Science.gov (United States)

    2010-06-11

    The Food and Drug Administration (FDA) published a final rule in the Federal Register of August 4, 2009 (74 FR 38686) which classified dental amalgam as a class II device, reclassified dental mercury from class I to class II, and designated special controls for dental amalgam, mercury, and amalgam alloy. The effective date of the rule was November 2, 2009. The final rule was published with an inadvertent error in the codified section. This document corrects that error. This action is being taken to ensure the accuracy of the agency's regulations.

  16. Full scale calcium bromide injection with subsequent mercury oxidation and removal within wet flue gas desulphurization system: Experience at a 700 MW coal-fired power facility

    Science.gov (United States)

    Berry, Mark Simpson

    The Environmental Protection Agency promulgated the Mercury and Air Toxics Standards rule, which requires that existing power plants reduce mercury emissions to meet an emission rate of 1.2 lb/TBtu on a 30-day rolling average and that new plants meet a 0.0002 lb/GWHr emission rate. This translates to mercury removals greater than 90% for existing units and greater than 99% for new units. Current state-of-the-art technology for the control of mercury emissions uses activated carbon injected upstream of a fabric filter, a costly proposition. For example, a fabric filter, if not already available, would require a 200M capital investment for a 700 MW size unit. A lower-cost option involves the injection of activated carbon into an existing cold-side electrostatic precipitator. Both options would incur the cost of activated carbon, upwards of 3M per year. The combination of selective catalytic reduction (SCR) reactors and wet flue gas desulphurization (wet FGD) systems have demonstrated the ability to substantially reduce mercury emissions, especially at units that burn coals containing sufficient halogens. Halogens are necessary for transforming elemental mercury to oxidized mercury, which is water-soluble. Plants burning halogen-deficient coals such as Power River Basin (PRB) coals currently have no alternative but to install activated carbon-based approaches to control mercury emissions. This research consisted of investigating calcium bromide addition onto PRB coal as a method of increasing flue gas halogen concentration. The treated coal was combusted in a 700 MW boiler and the subsequent treated flue gas was introduced into a wet FGD. Short-term parametric and an 83-day longer-term tests were completed to determine the ability of calcium bromine to oxidize mercury and to study the removal of the mercury in a wet FGD. The research goal was to show that calcium bromine addition to PRB coal was a viable approach for meeting the Mercury and Air Toxics Standards rule

  17. Neurotoxic impact of mercury on the central nervous system evaluated by neuropsychological tests and on the autonomic nervous system evaluated by dynamic pupillometry.

    Science.gov (United States)

    Milioni, Ana Luiza V; Nagy, Balázs V; Moura, Ana Laura A; Zachi, Elaine C; Barboni, Mirella T S; Ventura, Dora F

    2017-03-01

    Mercury vapor is highly toxic to the human body. The present study aimed to investigate the occurrence of neuropsychological dysfunction in former workers of fluorescent lamps factories that were exposed to mercury vapor (years after cessation of exposure), diagnosed with chronic mercurialism, and to investigate the effects of such exposure on the Autonomic Nervous System (ANS) using the non-invasive method of dynamic pupillometry. The exposed group and a control group matched by age and educational level were evaluated by the Beck Depression Inventory and with the computerized neuropsychological battery CANTABeclipse - subtests of working memory (Spatial Span), spatial memory (Spatial Recognition Memory), visual memory (Pattern Recognition Memory) and action planning (Stockings of Cambridge). The ANS was assessed by dynamic pupillometry, which provides information on the operation on both the sympathetic and parasympathetic functions. Depression scores were significantly higher among the former workers when compared with the control group. The exposed group also showed significantly worse performance in most of the cognitive functions assessed. In the dynamic pupillometry test, former workers showed significantly lower response than the control group in the sympathetic response parameter (time of 75% of pupillary recovery at 10cd/m 2 luminance). Our study found indications that are suggestive of cognitive deficits and losses in sympathetic autonomic activity among patients occupationally exposed to mercury vapor. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Economic evaluation of health benefits of mercury emission controls for China and the neighboring countries in East Asia

    International Nuclear Information System (INIS)

    Zhang, Wei; Zhen, Gengchong; Chen, Long; Wang, Huanhuan; Li, Ying; Ye, Xuejie; Tong, Yindong; Zhu, Yan; Wang, Xuejun

    2017-01-01

    Globally, coal-fired power plant (CFPP) is a major source of mercury. China is developing its first National Implementation Plan on Mercury Control, which priorities the control of emissions from CFPPs. While social benefits play an important role in designing environmental policies in China, the benefits associated with mercury control are not yet understood, mainly due to the scientific challenges to trace mercury's emissions-to-impacts path. This study evaluates the benefits of mercury reductions in China's CFPPs for China and its three neighboring countries in East Asia. Four policy scenarios are analyzed following the policies-to-impacts path, which links a global atmospheric model to health benefit analysis models to estimate the economic gains from avoided mercury-related adverse health outcomes under each scenario, and take into account key uncertainties in the path. Under the most stringent scenario, the benefits of mercury reduction by 2030 are projected to be $432 billion (95% CI: $166–941 billion), with the benefits for China and the neighboring countries accounting for 96% and 4% of the total benefits, respectively. Policy scenario analysis indicates that coal washing generates the greatest benefits in the near term, whereas upgrading air pollution control devices maximizes health benefits in the long term. - Highlights: • Benefits of mercury controls for China and neighboring countries are analyzed. • Policy analysis shows that coal washing generates the largest benefits in near term. • Upgrading air pollution control devices maximizes health benefits in long term. • For mercury controls, local policies contribute most to local benefits.

  19. Procedure 5 Quality Assurance Requirements For Vapor Phase Mercury Continuous Emissions Monitoring Systems And Sorbent Trap Monitoring Systems Used For Compliance Determination At Stationary Sources

    Science.gov (United States)

    Promulgated quality assurance Procedure 5 Quality Assurance Requirements For Vapor Phase Mercury Continuous Emissions Monitoring Systems And Sorbent Trap Monitoring Systems Used For Compliance Determination At Stationary Sources

  20. Method and apparatus for monitoring the flow of mercury in a system

    Science.gov (United States)

    Grossman, M.W.

    1987-12-15

    An apparatus and method for monitoring the flow of mercury in a system are disclosed. The equipment enables the entrainment of the mercury in a carrier gas e.g., an inert gas, which passes as mercury vapor between a pair of optically transparent windows. The attenuation of the emission is indicative of the quantity of mercury (and its isotopes) in the system. A 253.7 nm light is shone through one of the windows and the unabsorbed light is detected through the other window. The absorption of the 253.7 nm light is thereby measured whereby the quantity of mercury passing between the windows can be determined. The apparatus includes an in-line sensor for measuring the quantity of mercury. It includes a conduit together with a pair of apertures disposed in a face to face relationship and arranged on opposite sides of the conduit. A pair of optically transparent windows are disposed upon a pair of viewing tubes. A portion of each of the tubes is disposed inside of the conduit and within each of the apertures. The two windows are disposed in a face to face relationship on the ends of the viewing tubes and the entire assembly is hermetically sealed from the atmosphere whereby when 253.7 nm ultraviolet light is shone through one of the windows and detected through the other, the quantity of mercury which is passing by can be continuously monitored due to absorption which is indicated by attenuation of the amplitude of the observed emission. 4 figs.

  1. [Characteristics of mercury exchange flux between soil and atmosphere under the snow retention and snow melting control].

    Science.gov (United States)

    Zhang, Gang; Wang, Ning; Ai, Jian-Chao; Zhang, Lei; Yang, Jing; Liu, Zi-Qi

    2013-02-01

    Jiapigou gold mine, located in the upper Songhua River, was once the largest mine in China due to gold output, where gold extraction with algamation was widely applied to extract gold resulting in severe mercury pollution to ambient environmental medium. In order to study the characteristics of mercury exchange flux between soil (snow) and atmosphere under the snow retention and snow melting control, sampling sites were selected in equal distances along the slope which is situated in the typical hill-valley terrain unit. Mercury exchange flux between soil (snow) and atmosphere was determined with the method of dynamic flux chamber and in all sampling sites the atmosphere concentration from 0 to 150 cm near to the earth in the vertical direction was measured. Furthermore, the impact factors including synchronous meteorology, the surface characteristics under the snow retention and snow melting control and the mercury concentration in vertical direction were also investigated. The results are as follows: During the period of snow retention and melting the air mercury tends to gather towards valley bottom along the slope and an obvious deposit tendency process was found from air to the earth's surface under the control of thermal inversion due to the underlying surface of cold source (snow surface). However, during the period of snow melting, mercury exchange flux between the soil and atmosphere on the surface of the earth with the snow being melted demonstrates alternative deposit and release processes. As for the earth with snow covered, the deposit level of mercury exchange flux between soil and atmosphere is lower than that during the period of snow retention. The relationship between mercury exchange flux and impact factors shows that in snow retention there is a remarkable negative linear correlation between mercury exchange flux and air mercury concentration as well as between the former and the air temperature. In addition, in snow melting mercury exchange

  2. Effects from exposure to dental amalgam on systemic mercury levels in patients and dental school students.

    Science.gov (United States)

    de Oliveira, Marcelo Tomás; Pereira, Jefferson Ricardo; Ghizoni, Janaina Salomon; Bittencourt, Sandra Teixeira; Molina, Gustavo Otoboni

    2010-10-01

    The purpose of this study was to evaluate the systemic mercury levels in urine of patients and dental school students caused by exposure to silver amalgam. It is currently believed that occupational exposure shows the highest rate of potential for poisoning by mercury. Dental professionals are part of that quota, introducing concerns regarding the handling of dental amalgam. The study comprised 40 urine samples from 20 subjects, which were divided into four sampling groups: G1A (n = 10) composed of students before their first occupational contact; G1B (n = 10) composed of the same G1 students after their first contact; G2A (n = 10) composed of patients who needed to have dental restorations before amalgam removal; and G2B (n = 10) composed of patients who needed to have dental restoration after amalgam removal. Cold-vapor atomic absorption spectrophotometry (CVAAS) was used as the evaluation method. A statistically significant difference was found among dependent groups 1 and 2 (p = 0.0038), whereas mercury levels increased considerably after the first occupational contact of all subjects. Occupational exposure to dental amalgam poses a potential risk of increasing systemic mercury levels, although urine mercury levels in all the sample participants were below the limits of biologic tolerance.

  3. Mercury Control for Plants Firing Texas Lignite and Equipped with ESP-wet FGD

    Energy Technology Data Exchange (ETDEWEB)

    Katherine Dombrowski

    2009-12-31

    This report presents the results of a multi-year test program conducted as part of Cooperative Agreement DE-FC26-06NT42779, 'Mercury Control for Plants Firing Texas Lignite and Equipped with ESP-wet FGD.' The objective of this program was to determine the level of mercury removal achievable using sorbent injection for a plant firing Texas lignite fuel and equipped with an ESP and wet FGD. The project was primarily funded by the U.S. DOE National Energy Technology Laboratory. EPRI, NRG Texas, Luminant (formerly TXU), and AEP were project co-funders. URS Group was the prime contractor, and Apogee Scientific and ADA-ES were subcontractors. The host site for this program was NRG Texas Limestone Electric Generating Station (LMS) Units 1 and 2, located in Jewett, Texas. The plant fires a blend of Texas lignite and Powder River Basin (PRB) coal. Full-scale tests were conducted to evaluate the mercury removal performance of powdered sorbents injected into the flue gas upstream of the ESP (traditional configuration), upstream of the air preheater, and/or between electric fields within the ESP (Toxecon{trademark} II configuration). Phases I through III of the test program, conducted on Unit 1 in 2006-2007, consisted of three short-term parametric test phases followed by a 60-day continuous operation test. Selected mercury sorbents were injected to treat one quarter of the flue gas (e.g., approximately 225 MW equivalence) produced by Limestone Unit 1. Six sorbents and three injection configurations were evaluated and results were used to select the best combination of sorbent (Norit Americas DARCO Hg-LH at 2 lb/Macf) and injection location (upstream of the ESP) for a two-month performance evaluation. A mercury removal rate of 50-70% was targeted for the long-term test. During this continuous-injection test, mercury removal performance and variability were evaluated as the plant operated under normal conditions. Additional evaluations were made to determine any

  4. Toxecon Retrofit for Mercury and Mulit-Pollutant Control on Three 90-MW Coal-Fired Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Steven Derenne; Robin Stewart

    2009-09-30

    This U.S. Department of Energy (DOE) Clean Coal Power Initiative (CCPI) project was based on a cooperative agreement between We Energies and the DOE Office of Fossil Energy's National Energy Technology Laboratory (NETL) to design, install, evaluate, and demonstrate the EPRI-patented TOXECON{trademark} air pollution control process. Project partners included Cummins & Barnard, ADA-ES, and the Electric Power Research Institute (EPRI). The primary goal of this project was to reduce mercury emissions from three 90-MW units that burn Powder River Basin coal at the We Energies Presque Isle Power Plant in Marquette, Michigan. Additional goals were to reduce nitrogen oxide (NO{sub x}), sulfur dioxide (SO{sub 2}), and particulate matter emissions; allow reuse and sale of fly ash; advance commercialization of the technology; demonstrate a reliable mercury continuous emission monitor (CEM) suitable for use at power plants; and demonstrate recovery of mercury from the sorbent. Mercury was controlled by injection of activated carbon upstream of the TOXECON{trademark} baghouse, which achieved more than 90% removal on average over a 44-month period. During a two-week test involving trona injection, SO{sub 2} emissions were reduced by 70%, although no coincident removal of NOx was achieved. The TOXECON{trademark} baghouse also provided enhanced particulate control, particularly during startup of the boilers. On this project, mercury CEMs were developed and tested in collaboration with Thermo Fisher Scientific, resulting in a reliable CEM that could be used in the power plant environment and that could measure mercury as low as 0.1 {micro}g/m{sup 3}. Sorbents were injected downstream of the primary particulate collection device, allowing for continued sale and beneficial use of captured fly ash. Two methods for recovering mercury using thermal desorption on the TOXECON{trademark} PAC/ash mixture were successfully tested during this program. Two methods for using the TOXECON

  5. PILOT TESTING OF MERCURY OXIDATION CATALYSTS FOR UPSTREAM OF WET FGD SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Gary M. Blythe

    2003-01-21

    This document summarizes progress on Cooperative Agreement DE-FC26-01NT41185, Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems, during the time period October 1, 2002 through December 31, 2002. The objective of this project is to demonstrate at pilot scale the use of solid honeycomb catalysts to promote the oxidation of elemental mercury in the flue gas from coal combustion. The project is being funded by the U.S. DOE National Energy Technology Laboratory under Cooperative Agreement DE-FC26-01NT41185. EPRI, Great River Energy (GRE), and City Public Service (CPS) of San Antonio are project co-funders. URS Group is the prime contractor. The mercury catalytic oxidation process under development uses catalyst materials applied to honeycomb substrates to promote the oxidation of elemental mercury in the flue gas from coal-fired power plants that have wet lime or limestone flue gas desulfurization (FGD) systems. Oxidized mercury is removed in the wet FGD absorbers and co-precipitates with the byproducts from the FGD system. The co-precipitated mercury does not appear to adversely affect the disposal or reuse properties of the FGD byproduct. The current project testing previously identified, effective catalyst materials at a larger, pilot scale and in a commercial form, to provide engineering data for future fullscale designs. The pilot-scale tests will continue for up to 14 months at each of two sites to provide longer-term catalyst life data. This is the fifth full reporting period for the subject Cooperative Agreement. During this period, project efforts included starting up the pilot unit with three catalysts at the first site, conducting catalyst activity measurements, completing comprehensive flue gas sampling and analyses, and procuring additional catalysts for the pilot unit. This technical progress report provides an update on these efforts.

  6. Mercury emission from a temperate lake during autumn turnover

    International Nuclear Information System (INIS)

    Wollenberg, Jennifer L.; Peters, Stephen C.

    2009-01-01

    Lakes in temperate regions stratify during summer and winter months, creating distinct layers of water differentiated by their physical and chemical characteristics. When lakes mix in autumn and spring, mercury cycling may be affected by the chemical changes that occur during mixing. Sampling was conducted in Lake Lacawac, Eastern Pennsylvania, USA, throughout the autumn of 2007 to characterize changes in emission of gaseous elemental mercury (Hg 0 ) from the lake surface and dissolved mercury profiles in the water column during mixing. Water chemistry and weather parameters were also measured, including dissolved organic carbon (DOC), iron, and solar radiation which have been shown to interact with mercury species. Results indicate that emission of Hg 0 from the lake to the atmosphere during turnover was controlled both by solar radiation and by surface water mercury concentration. As autumn turnover progressed through the months of October and November, higher mercury concentration water from the hypolimnion mixed with epilimnetic water, increasing mercury concentration in epilimnetic waters. Dissolved absorbance was significantly correlated with mercury concentrations and with iron, but DOC concentrations were essentially constant throughout the study period and did not exhibit a relationship with either dissolved mercury concentrations or emission rates. Positive correlations between dissolved mercury and iron and manganese also suggest a role for these elements in mercury transport within the lake, but iron and manganese did not demonstrate a relationship with emission rates. This research indicates that consideration of seasonal processes in lakes is important when evaluating mercury cycling in aquatic systems

  7. Orbital multispectral mapping of Mercury with the MESSENGER Mercury Dual Imaging System: Evidence for the origins of plains units and low-reflectance material

    Science.gov (United States)

    Murchie, Scott L.; Klima, Rachel L.; Denevi, Brett W.; Ernst, Carolyn M.; Keller, Mary R.; Domingue, Deborah L.; Blewett, David T.; Chabot, Nancy L.; Hash, Christopher D.; Malaret, Erick; Izenberg, Noam R.; Vilas, Faith; Nittler, Larry R.; Gillis-Davis, Jeffrey J.; Head, James W.; Solomon, Sean C.

    2015-07-01

    A principal data product from MESSENGER's primary orbital mission at Mercury is a global multispectral map in eight visible to near-infrared colors, at an average pixel scale of 1 km, acquired by the Mercury Dual Imaging System. The constituent images have been calibrated, photometrically corrected to a standard geometry, and map projected. Global analysis reveals no spectral units not seen during MESSENGER's Mercury flybys and supports previous conclusions that most spectral variation is related to changes in spectral slope and reflectance between spectral end-member high-reflectance red plains (HRP) and low-reflectance material (LRM). Comparison of color properties of plains units mapped on the basis of morphology shows that the two largest unambiguously volcanic smooth plains deposits (the interior plains of Caloris and the northern plains) are close to HRP end members and have average color properties distinct from those of most other smooth plains and intercrater plains. In contrast, smaller deposits of smooth plains are nearly indistinguishable from intercrater plains on the basis of their range of color properties, consistent with the interpretation that intercrater plains are older equivalents of smooth plains. LRM having nearly the same reflectance is exposed in crater and basin ejecta of all ages, suggesting impact excavation from depth of material that is intrinsically dark or darkens very rapidly, rather than gradual darkening of exposed material purely by space weathering. A global search reveals no definitive absorptions attributable to Fe2+-containing silicates or to sulfides over regions 20 km or more in horizontal extent, consistent with results from MESSENGER's Mercury Atmospheric and Surface Composition Spectrometer. The only absorption-like feature identified is broad upward curvature of the spectrum centered near 600 nm wavelength. The feature is strongest in freshly exposed LRM and weak or absent in older exposures of LRM. We modeled spectra

  8. Method of controlling the mercury vapor pressure in a photo-chemical lamp or vapor filter used for Hg.sup.196 enrichment

    Science.gov (United States)

    Grossman, Mark W.

    1993-01-01

    The present invention is directed to a method of eliminating the cold spot zones presently used on Hg.sup.196 isotope separation lamps and filters by the use of a mercury amalgams, preferably mercury - indium amalgams. The use of an amalgam affords optimization of the mercury density in the lamp and filter of a mercury enrichment reactor, particularly multilamp enrichment reactors. Moreover, the use of an amalgam in such lamps and/or filters affords the ability to control the spectral line width of radiation emitted from lamps, a requirement for mercury enrichment.

  9. Method of controlling the mercury vapor pressure in a photo-chemical lamp or vapor filter used for Hg[sup 196] enrichment

    Science.gov (United States)

    Grossman, M.W.

    1993-02-16

    The present invention is directed to a method of eliminating the cold spot zones presently used on Hg[sup 196] isotope separation lamps and filters by the use of a mercury amalgams, preferably mercury - indium amalgams. The use of an amalgam affords optimization of the mercury density in the lamp and filter of a mercury enrichment reactor, particularly multilamp enrichment reactors. Moreover, the use of an amalgam in such lamps and/or filters affords the ability to control the spectral line width of radiation emitted from lamps, a requirement for mercury enrichment.

  10. Method of controlling the mercury vapor pressure in a photo-chemical lamp or vapor filter used for Hg196 enrichment

    International Nuclear Information System (INIS)

    Grossman, M.W.

    1993-01-01

    The present invention is directed to a method of eliminating the cold spot zones presently used on Hg 196 isotope separation lamps and filters by the use of a mercury amalgams, preferably mercury - indium amalgams. The use of an amalgam affords optimization of the mercury density in the lamp and filter of a mercury enrichment reactor, particularly multilamp enrichment reactors. Moreover, the use of an amalgam in such lamps and/or filters affords the ability to control the spectral line width of radiation emitted from lamps, a requirement for mercury enrichment

  11. Intentional intravenous mercury injection

    African Journals Online (AJOL)

    Three forms of mercury exist: elemental, inorganic and organic, all of which may be toxic with clinical consequences, depending on the type of exposure. Elemental mercury poisoning usually occurs via vapour inhalation, as mercury is well absorbed through the lungs. The central nervous system is then the major site of ...

  12. Measurement of volatilized mercury by a mini-system: a simple, reliable and reproducible technique

    Directory of Open Access Journals (Sweden)

    Luciana Cursino

    2003-12-01

    Full Text Available A simple and easy new technique for volatilized mercury determination in biological systems was developed. This technique is fast and sensitive and can overcome the problems that arise due to the extremely low readings during the measurements and reproducibility in biological material (bacteria. It measures directly the volatilized metallic mercury of bacteria by means of a chemical adsorbent in a coupled mini-system, as a modified technique for mercury in air analysis. It is potentially of interest to the bioremediation and bacterial mercury resistance communitiesUma metodologia simples foi desenvolvida para medir o mercúrio volatilizado em um sistema biológico. Esta técnica é rápida, sensível e pode superar as dificuldades freqüentemente observadas em material biológico tais como, leituras extremamente baixas e a sua reprodutibilidade. Este sistema mede diretamente por meio de um adsorvente químico acoplado a um mini-sistema o mercúrio metálico volatilizado pela bactéria. Para isto, a metodologia para a análise de mercúrio em amostras de ar foi modificada. Esta técnica é de interesse para a biorremediação e para o estudo de comunidades bacterianas resistentes ao mercúrio.

  13. JV TASK 45-MERCURY CONTROL TECHNOLOGIES FOR ELECTRIC UTILITIES BURNING LIGNITE COAL, PHASE I BENCH-AND PILOT-SCALE TESTING

    Energy Technology Data Exchange (ETDEWEB)

    John H. Pavlish; Michael J. Holmes; Steven A. Benson; Charlene R. Crocker; Edwin S. Olson; Kevin C. Galbreath; Ye Zhuang; Brandon M. Pavlish

    2003-10-01

    -based activated (800 C, 1472 F) carbons required a shorter (15-minute) conditioning period in the simulated lignite flue gas and captured gaseous mercury more effectively than those activated at 750 C (1382 F). Subsequent tests with higher acid gas concentrations including 50 ppm HCl showed no early mercury breakthrough for either the activated (750 C, 1382 F) Bienfait carbon or the DARCO FGD. Although these high acid gas tests yielded better mercury capture initially, significant breakthrough of mercury ultimately occurred sooner than during the simulated lignite flue gas tests. The steam-activated char, provided by Luscar Ltd., and DARCO FGD, provided by NORIT Americas, were evaluated for mercury removal potential in a 580 MJ/hr (550,000-Btu/hr) pilot-scale coal combustion system equipped with four particulate control devices: (1) an electrostatic precipitator (ESP), (2) a fabric filter (FF), (3) the Advanced Hybrid{trademark} filter, and (4) an ESP and FF in series, an EPRI-patented TOXECON{trademark} technology. The Ontario Hydro method and continuous mercury monitors were used to measure mercury species concentrations at the inlet and outlet of the control technology devices with and without sorbent injection. Primarily Hg{sup o} was measured when lignite coals from the Poplar River Plant and Freedom Mine were combusted. The effects of activated Luscar char, DARCO FGD, injection rates, particle size, and gas temperature on mercury removal were evaluated for each of the four particulate control device options. Increasing injection rates and decreasing gas temperatures generally promoted mercury capture in all four control devices. Relative to data reported for bituminous and subbituminous coal combustion flue gases, higher sorbent injection rates were generally required for the lignite coal to effectively remove mercury. Documented results in this report provide the impacts of these and other parameters and provide the inputs needed to direct Phase II of the project.

  14. Mercury cadmium telluride implanted junction profile measurement and depth control

    Science.gov (United States)

    Zhou, Songmin; Lin, Chun; Li, Haibin; Wei, Yanfeng; Ye, Zhenhua; Ding, Ruijun; He, Li

    2014-06-01

    In this work, a novel junction profile measurement method is proposed. A serial of junctions were fabricated by B+ implantation. Then a beveled bar which was about 10mm long and several micrometers deep was formed by carefully controlled wet-etching. The remaining depth of n region changes from the full depth that is about 5.3mm after ion implantation to zero depending on its lateral position and the slope of the etching bar. Voltage-current and Laser Beam Induced Current (LBIC) measurements were applied to determine the HgCdTe junction edge. The LBIC signal orrectification characteristic indicates the existence of a PN junction. The junction depth is extracted from the position where the PN junction disappears and the slope of the etching bar. The junction depth of intrinsic doped HgCdTe was measured, which is about 2.4μm. A significant 0.4mm thick N-region was observed. Moreover, junction depths of samples annealed for different time were also investigated. By this method, it's possible to measure the three dimensional profile of a planar PN junction.

  15. An update on DOE's Phase II and Phase III mercury control technology R and D program

    Energy Technology Data Exchange (ETDEWEB)

    Feeley, Thomas J. III.; Brickett, Lynn A.; Miller, Charles E. [National Energy Technology Laboratory, U.S. Department of Energy, 626 Cochrans Mill Road, Pittsburgh, PA 15236 (United States); Jones, Andrew P.; Murphy, James T. [Science Applications International Corporation, National Energy Technology Laboratory, Pittsburgh, PA 15236 (United States); O' Palko, B. Andrew [National Energy Technology Laboratory, U.S. Department of Energy, 3610 Collins Ferry Road, Morgantown, WV 26507 (United States)

    2009-11-15

    The U.S. Department of Energy's National Energy Technology Laboratory, under the Office of Fossil Energy's Innovations for Existing Plants Program, carried out a comprehensive Hg research and development program for coal-fired power generation facilities since the mid-1990s. Working collaboratively with the U.S. Environmental Protection Agency, the Electric Power Research Institute, power plant operators, state and local agencies, and a host of research organizations and academic institutions, the Program identified the major factors that affect mercury speciation and capture in coal combustion flue gas and funneled this knowledge into the development of a suite of mercury control technologies for the diverse fleet of U.S. coal-fired power plants. The high performance observed during full-scale field testing has given coal-fired power plant operators the confidence to begin deploying technology. As of March 2009, more than 130 full-scale activated carbon injection systems have been ordered by the U.S. coal-fired power generators. These contracts include both new and retrofit installations and represent over 55 GW of coal-based electric generating capacity. (author)

  16. Sensing Mercury for Biomedical and Environmental Monitoring

    Directory of Open Access Journals (Sweden)

    Julia Xiaojun Zhao

    2009-07-01

    Full Text Available Mercury is a very toxic element that is widely spread in the atmosphere, lithosphere, and surface water. Concentrated mercury poses serious problems to human health, as bioaccumulation of mercury within the brain and kidneys ultimately leads to neurological diseases. To control mercury pollution and reduce mercury damage to human health, sensitive determination of mercury is important. This article summarizes some current sensors for the determination of both abiotic and biotic mercury. A wide array of sensors for monitoring mercury is described, including biosensors and chemical sensors, while piezoelectric and microcantilever sensors are also described. Additionally, newly developed nanomaterials offer great potential for fabricating novel mercury sensors. Some of the functional fluorescent nanosensors for the determination of mercury are covered. Afterwards, the in vivo determination of mercury and the characterization of different forms of mercury are discussed. Finally, the future direction for mercury detection is outlined, suggesting that nanomaterials may provide revolutionary tools in biomedical and environmental monitoring of mercury.

  17. Mercury Wet Scavenging and Deposition Differences by Precipitation Type.

    Science.gov (United States)

    Kaulfus, Aaron S; Nair, Udaysankar; Holmes, Christopher D; Landing, William M

    2017-03-07

    We analyze the effect of precipitation type on mercury wet deposition using a new database of individual rain events spanning the contiguous United States. Measurements from the Mercury Deposition Network (MDN) containing single rainfall events were identified and classified into six precipitation types. Mercury concentrations in surface precipitation follow a power law of precipitation depth that is modulated by precipitation system morphology. After controlling for precipitation depth, the highest mercury deposition occurs in supercell thunderstorms, with decreasing deposition in disorganized thunderstorms, quasi-linear convective systems (QLCS), extratropical cyclones, light rain, and land-falling tropical cyclones. Convective morphologies (supercells, disorganized, and QLCS) enhance wet deposition by a factor of at least 1.6 relative to nonconvective morphologies. Mercury wet deposition also varies by geographic region and season. After controlling for other factors, we find that mercury wet deposition is greater over high-elevation sites, seasonally during summer, and in convective precipitation.

  18. Patterns and controls of mercury accumulation in sediments from three thermokarst lakes on the Arctic Coastal Plain of Alaska

    Science.gov (United States)

    Burke, Samantha M.; Zimmerman, Christian E.; Branfireun, Brian A.; Koch, Joshua C.; Swanson, Heidi K.

    2018-01-01

    The biogeochemical cycle of mercury will be influenced by climate change, particularly at higher latitudes. Investigations of historical mercury accumulation in lake sediments inform future predictions as to how climate change might affect mercury biogeochemistry; however, in regions with a paucity of data, such as the thermokarst-rich Arctic Coastal Plain of Alaska (ACP), the trajectory of mercury accumulation in lake sediments is particularly uncertain. Sediment cores from three thermokarst lakes on the ACP were analyzed to understand changes in, and drivers of, Hg accumulation over the past ~ 100 years. Mercury accumulation in two of the three lakes was variable and high over the past century (91.96 and 78.6 µg/m2/year), and largely controlled by sedimentation rate. Mercury accumulation in the third lake was lower (14.2 µg/m2/year), more temporally uniform, and was more strongly related to sediment Hg concentration than sedimentation rate. Sediment mercury concentrations were quantitatively related to measures of sediment composition and VRS-inferred chlorophyll a, and sedimentation rates were related to various catchment characteristics. These results were compared to data from 37 previously studied Arctic and Alaskan lakes. Results from the meta-analysis indicate that thermokarst lakes have significantly higher and more variable Hg accumulation rates than non-thermokarst lakes, suggesting that certain properties (e.g., thermal erosion, thaw slumping, low hydraulic conductivity) likely make lakes prone to high and variable Hg accumulation rates. Differences and high variability in Hg accumulation among high latitude lakes highlight the complexity of predicting future climate-related change impacts on mercury cycling in these environments.

  19. Controls on boreal peat combustion and resulting emissions of carbon and mercury

    Science.gov (United States)

    Kohlenberg, Andrew J.; Turetsky, Merritt R.; Thompson, Dan K.; Branfireun, Brian A.; Mitchell, Carl P. J.

    2018-03-01

    Warming in the boreal forest region has already led to changes in the fire regime. This may result in increasing fire frequency or severity in peatlands, which could cause these ecosystems to shift from a net sink of carbon (C) to a net source of C to the atmosphere. Similar to C cycling, peatlands serve as a net sink for mercury (Hg), which binds strongly to organic matter and accumulates in peat over time. This stored Hg is also susceptible to re-release to the atmosphere during peat fires. Here we investigate the physical properties that influence depth of burn in experimental peat columns and the resulting emissions of CO, CO2, CH4, and gaseous and particulate Hg. As expected, bulk density and soil moisture content were important controls on depth of burn, CO2 emissions, and CO emissions. However, our results show that CH4 and Hg emissions are insensitive to combustion temperature or fuel moisture content. Emissions during the burning of peat, across a wide range of moisture conditions, were associated with low particulate Hg and high gaseous Hg release. Due to strong correlations between total Hg and CO emissions and because high Hg emissions occurred despite incomplete combustion of total C, our results suggest that Hg release during peat burning is governed by the thermodynamics of Hg reduction more so than by the release of Hg associated with peat combustion. Our measured emissions ratios, particularly for CH4:CO2, are higher than values typically used in the upscaling of boreal forest or peatland fire emissions. These emission ratios have important implications not only for our understanding of smouldering chemistry, but also for potential influences of peat fires on the Earth’s climate system.

  20. Phytoremediation of Ionic and Methyl Mercury Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2005-06-01

    control the chemical speciation, electrochemical state, transport, and aboveground binding of mercury in order to manage this toxicant. To advance this mercury phytoremediation strategy, our planned research focuses on the following Specific Aims: (1) to increase the transport of mercury to aboveground tissue; (2) to identify small mercury binding peptides that enhance hyperaccumulation aboveground; (3) to test the ability of multiple genes acting together to enhance resistance and hyperaccumulation; (4) to construct a simple molecular system for creating male/female sterility, allowing engineered grass, shrub, and tree species to be released indefinitely at contaminated sites; (5) to test the ability of transgenic cottonwood and rice plants to detoxify ionic mercury and prevent methylmercury release from contaminated sediment; and (6) to initiate field testing with transgenic cottonwood and rice for the remediation of methylmercury and ionic mercury. The results of these experiments will enable the phytoremediation of methyl- and ionic mercury by a wide spectrum of deep-rooted, fast-growing plants adapted to diverse environments. We have made significant progress on all six of these specific aims as summarized below.

  1. Dating thrust systems on Mercury: new clues on the thermal evolution of the planet

    Science.gov (United States)

    Giacomini, Lorenza; Massironi, Matteo; Ferrari, Sabrina; Zagato, Nicola

    2016-04-01

    The global tectonic scenario of Mercury is dominated by contractional features mainly represented by lobate scarps. These structures are the expression of surface-breaking thrust faults and are linear or arcuate features widely distributed on Mercury. Since they display a broad distribution of orientations, lobate scarps are thought to be related to a global contractional strain, associated to planetary cooling (Watters et al., 1998, Geology, 26, 991-994). The age determination of these features will contribute to better constrain whether limits could be placed on when the contraction occurred. For these reasons we dated two thrust systems, located in different regions of Mercury. The first system is located at the edge between Kuiper and Beethoven quadrangle (latitude 9°20'N-23°42'S and longitude 72°73'-59°52'W). These 1500-long thrust system is constituted by several lobate scarps with a NNE-SSW orientation. The second thrust system considered in this work is the Enterprise Rupes, a 820 km-long scarp system that cuts the Rembrandt basin. We dated the activity of these systems through the buffered crater counting technique, which is used to derive absolute model ages of linear landforms (e.g. Fassett and Head, 2008, Icarus, 198, 37-56; Giacomini, et al, 2015, GSL, 401, 291-311). The results gave comparable ages for the two systems and suggest that the activity along major rupes all around planet Mercury have most probably begun before 3.5 Ga. This will give us new clues to better understanding the thermal evolution of the planet.

  2. Solar System Exploration Augmented by In-Situ Resource Utilization: Human Mercury and Saturn Exploration

    Science.gov (United States)

    Palaszewski, Bryan

    2015-01-01

    Human and robotic missions to Mercury and Saturn are presented and analyzed. Unique elements of the local planetary environments are discussed and included in the analyses and assessments. Using historical studies of space exploration, in-situ resource utilization (ISRU), and industrialization all point to the vastness of natural resources in the solar system. Advanced propulsion benefitted from these resources in many way. While advanced propulsion systems were proposed in these historical studies, further investigation of nuclear options using high power nuclear thermal and nuclear pulse propulsion as well as advanced chemical propulsion can significantly enhance these scenarios. Updated analyses based on these historical visions will be presented. Nuclear thermal propulsion and ISRU enhanced chemical propulsion landers are assessed for Mercury missions. At Saturn, nuclear pulse propulsion with alternate propellant feed systems and Titan exploration with chemical propulsion options are discussed.

  3. Field Evaluation of MERCEM Mercury Emission Analyzer System at the Oak Ridge TSCA Incinerator East Tennessee Technology Park Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    None

    2000-03-01

    The authors reached the following conclusions: (1) The two-month evaluation of the MERCEM total mercury monitor from Perkin Elmer provided a useful venue in determining the feasibility of using a CEM to measure total mercury in a saturated flue gas. (2) The MERCEM exhibited potential at a mixed waste incinerator to meet requirements proposed in PS12 under conditions of operation with liquid feeds only at stack mercury concentrations in the range of proposed MACT standards. (3) Performance of the MERCEM under conditions of incinerating solid and liquid wastes simultaneously was less reliable than while feeding liquid feeds only for the operating conditions and configuration of the host facility. (4) The permeation tube calibration method used in this test relied on the CEM internal volumetric and time constants to relate back to a concentration, whereas a compressed gas cylinder concentration is totally independent of the analyzer mass flowmeter and flowrates. (5) Mercury concentration in the compressed gas cylinders was fairly stable over a 5-month period. (6) The reliability of available reference materials was not fully demonstrated without further evaluation of their incorporation into routine operating procedures performed by facility personnel. (7) The degree of mercury control occurring in the TSCA Incinerator off-gas cleaning system could not be quantified from the data collected in this study. (8) It was possible to conduct the demonstration at a facility incinerating radioactively contaminated wastes and to release the equipment for later unrestricted use elsewhere. (9) Experience gained by this testing answered additional site-specific and general questions regarding the operation and maintenance of CEMs and their use in compliance monitoring of total mercury emissions from hazardous waste incinerators.

  4. PRELIMINARY ESTIMATES OF PERFORMANCE AND COST OF MERCURY EMISSION CONTROL TECHNOLOGY APPLICATIONS ON ELECTRIC UTILITY BOILERS: AN UPDATE

    Science.gov (United States)

    The paper presents estimates of performance levels and related costs associated with controlling mercury (Hg) emissions from coal-fired power plants using either powdered activated carbon (PAC) injection or multipollutant control in which Hg capture is enhanced in existing and ne...

  5. Applicability of the Mercury Controlled Volatilization Technique in the Cerco Minero de Almadenejos

    International Nuclear Information System (INIS)

    Sanchez, L.; Sierra, M. J.; Millan, R.

    2013-01-01

    This work study the case of the Cerco Minero de Almadenejos (Ciudad Real), that is an important archaeological mine site in the region. In this place, different contamination levels can be finding in the soil and installations. The recovery of this site it will be of interest for the socio-economic development of the area. A preliminary study of the site has been carried out, in order to evaluate the possibility of the application of an in situ controlled mercury volatilization process as an alternative remediation technique. In case of reaching the established legal mercury levels, it could be possible to change the land use of the site. The proposed methodology includes the possibility of control the time required for a complete treatment as a function of the initial contamination level, in this way, the soil and installations decontamination process is performed by a non-destructive way. Finally, the proposed technology respects the old metallurgical plant where cinnabar was treated and burned, having the furnaces an elevated historical value whose restoration and conservation is important for the future use of the site. (Author) 20 refs.

  6. Mercury Toolset for Spatiotemporal Metadata

    Science.gov (United States)

    Devarakonda, Ranjeet; Palanisamy, Giri; Green, James; Wilson, Bruce; Rhyne, B. Timothy; Lindsley, Chris

    2010-06-01

    Mercury (http://mercury.ornl.gov) is a set of tools for federated harvesting, searching, and retrieving metadata, particularly spatiotemporal metadata. Version 3.0 of the Mercury toolset provides orders of magnitude improvements in search speed, support for additional metadata formats, integration with Google Maps for spatial queries, facetted type search, support for RSS (Really Simple Syndication) delivery of search results, and enhanced customization to meet the needs of the multiple projects that use Mercury. It provides a single portal to very quickly search for data and information contained in disparate data management systems, each of which may use different metadata formats. Mercury harvests metadata and key data from contributing project servers distributed around the world and builds a centralized index. The search interfaces then allow the users to perform a variety of fielded, spatial, and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fast search results to the user, while allowing data providers to advertise the availability of their data and maintain complete control and ownership of that data. Mercury periodically (typically daily)harvests metadata sources through a collection of interfaces and re-indexes these metadata to provide extremely rapid search capabilities, even over collections with tens of millions of metadata records. A number of both graphical and application interfaces have been constructed within Mercury, to enable both human users and other computer programs to perform queries. Mercury was also designed to support multiple different projects, so that the particular fields that can be queried and used with search filters are easy to configure for each different project.

  7. Mercury Toolset for Spatiotemporal Metadata

    Science.gov (United States)

    Wilson, Bruce E.; Palanisamy, Giri; Devarakonda, Ranjeet; Rhyne, B. Timothy; Lindsley, Chris; Green, James

    2010-01-01

    Mercury (http://mercury.ornl.gov) is a set of tools for federated harvesting, searching, and retrieving metadata, particularly spatiotemporal metadata. Version 3.0 of the Mercury toolset provides orders of magnitude improvements in search speed, support for additional metadata formats, integration with Google Maps for spatial queries, facetted type search, support for RSS (Really Simple Syndication) delivery of search results, and enhanced customization to meet the needs of the multiple projects that use Mercury. It provides a single portal to very quickly search for data and information contained in disparate data management systems, each of which may use different metadata formats. Mercury harvests metadata and key data from contributing project servers distributed around the world and builds a centralized index. The search interfaces then allow the users to perform a variety of fielded, spatial, and temporal searches across these metadata sources. This centralized repository of metadata with distributed data sources provides extremely fast search results to the user, while allowing data providers to advertise the availability of their data and maintain complete control and ownership of that data. Mercury periodically (typically daily) harvests metadata sources through a collection of interfaces and re-indexes these metadata to provide extremely rapid search capabilities, even over collections with tens of millions of metadata records. A number of both graphical and application interfaces have been constructed within Mercury, to enable both human users and other computer programs to perform queries. Mercury was also designed to support multiple different projects, so that the particular fields that can be queried and used with search filters are easy to configure for each different project.

  8. MERCURY REMOVAL IN A NON-THERMAL, PLASMA-BASED MULTI-POLLUTANT CONTROL TECHNOLOGY FOR UTILITY BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    Matthew B. Loomis

    2004-05-01

    This technical report describes the results from Task 1 of the Cooperative Agreement. Powerspan has installed, tested, and validated Hg SCEMS systems for measuring oxidized and elemental mercury at the pilot facility at R.E. Burger Generating Station in Shadyside, Ohio. When operating properly, these systems are capable of providing near real-time monitoring of inlet and outlet gas flow streams and are capable of extracting samples from different locations to characterize mercury removal at these different ECO process stages. This report discusses the final configuration of the Hg CEM systems and the operating protocols that increase the reliability of the HG SCEM measurements. Documentation on the testing done to verify the operating protocols is also provided. In addition the report provides details on the protocols developed and used for measurement of mercury in process liquid streams and in captured ash.

  9. Air/surface exchange processes of mercury and their linkage to atmospheric pools

    International Nuclear Information System (INIS)

    Bahlmann, Enno; Ebinghaus, Ralf

    2001-01-01

    The atmospheric mercury cycle is strongly linked to the terrestrial, aquatic and biologic cycle of mercury via air/surface exchange processes. In order to quantify mercury fluxes from and to the atmosphere to predict local and regional source contributions the methods for flux measurements as well as the physicochemical factors controlling air/surface exchange processes must be assessed. We will describe methods for the determination of mercury and mercury species in ambient air which are basic for investigation of air/surface exchange processes. Further on we will describe approaches for studying the physicochemical factors controlling this processes by using a new laboratory flux measurement system. (author)

  10. Mercury pollution on district of Dimembe river system North Sulawesi, Indonesia, due to traditional gold mining activities

    Science.gov (United States)

    Ayhuan, D.; Atteng, O.; Dondokambey, A.; Randuk, M.

    2003-05-01

    Mercury contamination caused by the amalgamation of gold in small scale gold mining is a environmental problem. Small-scale gold mining (SSGM) is common in mineral endowed developing countries. It offers an important means of livehood and has served as a safety net in times of natural calamities or economic distress. In north Sulawesi Province alone, approximately 22,000 small-scale gold miners were active in 1998, and produced an estimated 10 tonnes of gold bullion. Activities of traditional / illegal gold mining (PETI) in Dimembe of district, which is located in Minahasa Regency, North Sulawesi Province. The major environmental concern associated with PETI in mercury pollution from processing of gold-bearing ore. In both the inorganic and organic forms, mercury is one of the most toxic substances to humans. One of the environmental pollution is water pollution on district of Dimembe river system that is probably caused by the use of mercury (Hg) in processing mine ore. This mercury is used in an iron rolling vessel, wllich is called tromol. Mercury concentration at employed in this operation reaches 1 kg out of 30 kg ore. Sampling stage was conducted at Warat river, downstream Taiawaan river, Merut river and Kadumut river on late April 2002 by BAPEDALDA team together with Health Laboratory staff. Material which were sampled was water. Sampling methods carried out were bottle sample immersed about 10 cm below the water surface. The analysis method used was mercury analyzer. The analysis result show that total concentration of mercury range from 1. 69 to 25. 54 ppb. This concentration is closed to Water Quality Standard IV Class that is 0.005 mg/L (Regulation Government No. 82/2001). The result of this research indicate that the district of Dimembe river system in the gold mining area have been contaminated by mercury.

  11. Solar System Exploration Augmented by In-Situ Resource Utilization: Mercury and Saturn Propulsion Investigations

    Science.gov (United States)

    Palaszewski, Bryan

    2016-01-01

    Human and robotic missions to Mercury and Saturn are presented and analyzed with a range of propulsion options. Historical studies of space exploration, in-situ resource utilization (ISRU), and industrialization all point to the vastness of natural resources in the solar system. Advanced propulsion benefitted from these resources in many ways. While advanced propulsion systems were proposed in these historical studies, further investigation of nuclear options using high power nuclear thermal and nuclear pulse propulsion as well as advanced chemical propulsion can significantly enhance these scenarios. Updated analyses based on these historical visions will be presented. Nuclear thermal propulsion and ISRU enhanced chemical propulsion landers are assessed for Mercury missions. At Saturn, nuclear pulse propulsion with alternate propellant feed systems and Titan exploration with chemical propulsion options are discussed. In-situ resource utilization was found to be critical in making Mercury missions more amenable for human visits. At Saturn, refueling using local atmospheric mining was found to be difficult to impractical, while refueling the Saturn missions from Uranus was more practical and less complex.

  12. Toxicological aspects on the release and systemic uptake of mercury from dental amalgam.

    Science.gov (United States)

    Ekstrand, J; Björkman, L; Edlund, C; Sandborgh-Englund, G

    1998-04-01

    This paper summarizes some recent reports on mercury release from amalgam fillings and resulting concentrations in biological fluids, development of antibiotic resistance, and kidney function. In a series of studies of subjects with amalgam fillings, mercury (Hg) levels were followed in saliva, feces, blood, plasma, and urine before and until 60 d after removal of all of the fillings. The Hg concentrations in saliva remained elevated for at least 1 wk, suggesting that dissolved Hg vapor is not the major source of mercury in mixed saliva. An absorption phase of Hg was seen in plasma during 24 h after amalgam removal. After 60 d the plasma Hg concentration was reduced to 40%, of the baseline level. The decrease per amalgam surface was 0.11 nmol/l (range 0.02 0.40). The Hg level in feces increased two orders of magnitude two days after amalgam removal. At day 60, the median Hg concentration was still slightly higher than the median value of the amalgam free control group. The resistance patterns of the oral and intestinal microflora in these subjects were also studied. In the intestinal microflora, the relative amount of intestinal microorganisms resistant to 50 microM HgCl2 peaked 7 d after removal of the amalgam fillings, with a median value per sample of 6.1%, compared to 1.3% in samples collected prior to the Hg exposure. However, no statistical differences in the resistance pattern of the oral microflora were detected between the control and the experimental groups. A number of sensitive kidney function parameters were measured 1 wk before and 1, 2, and 60 d after amalgam removal. No effects on the various kidney parameters studied were recorded. According to the conclusions of independent evaluations from different state health agencies, the release of mercury from dental amalgam does not present any non-acceptable risk to the general population.

  13. Nonflame atomic absorption determination of total mercury in natural waters using an HS-3 mercury-hydride system

    Energy Technology Data Exchange (ETDEWEB)

    Evdokimova, E.V.; Solov`eva, M.Kh.; Telegin, G.F. [Institute of Problems in the Technology of Microelectronics and High-Purity Materials, Moscow (Russian Federation)

    1995-02-01

    A method for nonflame atomic absorption determination of mercury with a detection limit of 1 x 10{sup -3} {mu}g/ml in natural waters without preconcentration is described. The method can be applied successfully in analysis of the environment.

  14. Biogeochemistry of mercury in a river-reservoir system: impact of an inactive chloralkali plant on the Holston River-Cherokee Reservoir, Virginia and Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, S. G.; Lindberg, S. E.; Turner, R. R.; Huckabee, J. W.; Strand, R. H.; Lund, J. R.; Andren, A. W.

    1980-08-01

    Elevated mercury concentrations in fish species from the North Fork of the Holston River were observed in the early 1970's. The source of the mercury was a chloralkali plant which had ceased operation in 1972. Mercury continues to be released to the river from two large (approx. 40-ha) waste disposal ponds at the plant site. This report presents results of a study of the emission of mercury to the environment from the abandoned waste ponds and of the distribution of mercury in water, sediment, and biota of the Holston River-Cherokee Reservoir System in Virginia and eastern Tennessee.

  15. Quantitative evaluation of environmental factors influencing the dynamics of mercury in the aquatic systems. Highlights and achievements

    International Nuclear Information System (INIS)

    Akagi, Hirokatsu

    2002-01-01

    The development of a combined mercury extraction - speciation technique for total mercury and methylinercury determination in various biological and environmental media have been established to study and evaluate environmental factors influencing the dynamics of mercury in aquatic systems. Comparability studies of the results from the conventional and radiochemical techniques were planned for the 1st year of the CRP. Validation of the radiochemical method will be undertaken during the current CRP because of constraints in obtaining the appropriate radiotracers. The use of radiotracer techniques will be undertaken to investigate the generation and distribution of methylmercury in the river water - sediment systems using 203 Hg. The improved conventional analytical procedure uses the cold vapor atomic absorption spectrometry for the determination of total mercury in biological and environmental samples. For methylmercury determination, samples are analyzed using combined techniques of dithizone extraction and gas chromatograpy with electron capture detection

  16. Geochemistry, geochronology, mineralogy, and geology suggest sources of and controls on mineral systems in the southern Toquima Range, Nye County, Nevada; with geochemistry maps of gold, silver, mercury, arsenic, antimony, zinc, copper, lead, molybdenum, bismuth, iron, titanium, vanadium, cobalt, beryllium, boron, fluorine, and sulfur; and with a section on lead associations, mineralogy and paragenesis, and isotopes

    Science.gov (United States)

    Shawe, Daniel R.; Hoffman, James D.; Doe, Bruce R.; Foord, Eugene E.; Stein, Holly J.; Ayuso, Robert A.

    2003-01-01

    Geochemistry maps showing the distribution and abundance of 18 elements in about 1,400 rock samples, both mineralized and unmineralized, from the southern Toquima Range, Nev., indicate major structural and lithologic controls on mineralization, and suggest sources of the elements. Radiometric age data, lead mineralogy and paragenesis data, and lead-isotope data supplement the geochemical and geologic data, providing further insight into timing, sources, and controls on mineralization. Major zones of mineralization are centered on structural margins of calderas and principal northwest-striking fault zones, as at Round Mountain, Manhattan, and Jefferson mining districts, and on intersections of low-angle and steep structures, as at Belmont mining district. Paleozoic sedimentary rocks, mostly limestones (at Manhattan, Jefferson, and Belmont districts), and porous Oligocene ash-flow tuffs (at Round Mountain district) host the major deposits, although all rock types have been mineralized as evidenced by numerous prospects throughout the area. Principal mineral systems are gold-silver at Round Mountain where about 7 million ounces of gold and more than 4 million ounces of silver has been produced; gold at Gold Hill in the west part of the Manhattan district where about a half million ounces of gold has been produced; gold-mercury-arsenic-antimony in the east (White Caps) part of the Manhattan district where a few hundred thousand ounces of gold has been produced; and silver-lead-antimony at Belmont where more than 150,000 ounces of silver has been produced. Lesser amounts of gold and silver have been produced from the Jefferson district and from scattered mines elsewhere in the southern Toquima Range. A small amount of tungsten was produced from mines in the granite of the Round Mountain pluton exposed east of Round Mountain, and small amounts of arsenic, antimony, and mercury have been produced elsewhere in the southern Toquima Range. All elements show unique

  17. Rethinking mercury: the role of selenium in the pathophysiology of mercury toxicity.

    Science.gov (United States)

    Spiller, Henry A

    2018-05-01

    There is increasing evidence that the pathophysiological target of mercury is in fact selenium, rather than the covalent binding of mercury to sulfur in the body's ubiquitous sulfhydryl groups. The role of selenium in mercury poisoning is multifaceted, bidirectional, and central to understanding the target organ toxicity of mercury. An initial search was performed using Medline/PubMed, Toxline, Google Scholar, and Google for published work on mercury and selenium. These searches yielded 2018 citations. Publications that did not evaluate selenium status or evaluated environmental status (e.g., lake or ocean sediment) were excluded, leaving approximately 500 citations. This initial selection was scrutinized carefully and 117 of the most relevant and representative references were selected for use in this review. Binding of mercury to thiol/sulfhydryl groups: Mercury has a lower affinity for thiol groups and higher affinity for selenium containing groups by several orders of magnitude, allowing for binding in a multifaceted way. The established binding of mercury to thiol moieties appears to primarily involve the transport across membranes, tissue distribution, and enhanced excretion, but does not explain the oxidative stress, calcium dyshomeostasis, or specific organ injury seen with mercury. Effects of mercury on selenium and the role this plays in the pathophysiology of mercury toxicity: Mercury impairs control of intracellular redox homeostasis with subsequent increased intracellular oxidative stress. Recent work has provided convincing evidence that the primary cellular targets are the selenoproteins of the thioredoxin system (thioredoxin reductase 1 and thioredoxin reductase 2) and the glutathione-glutaredoxin system (glutathione peroxidase). Mercury binds to the selenium site on these proteins and permanently inhibits their function, disrupting the intracellular redox environment. A number of other important possible target selenoproteins have been identified

  18. EURISOL-DS METEX: Cooling and Temperature Control of the Mercury Loop

    CERN Document Server

    Stefan Joray

    The cooling of the mercury loop is described on pages two, three and four. The gaps in the water jackets of the heat exchangers are too large and the cooling water capacity is too low. Convection from the wall into water is bad. The mercury temperature is too high. On page five is a proposal how the mercury temperature can be kept low and constant.

  19. Automatic control systems engineering

    International Nuclear Information System (INIS)

    Shin, Yun Gi

    2004-01-01

    This book gives descriptions of automatic control for electrical electronics, which indicates history of automatic control, Laplace transform, block diagram and signal flow diagram, electrometer, linearization of system, space of situation, state space analysis of electric system, sensor, hydro controlling system, stability, time response of linear dynamic system, conception of root locus, procedure to draw root locus, frequency response, and design of control system.

  20. Study on the role of catalase for uptake of metallic mercury Part 3 In vitro oxidation of metallic mercury by catalase and hydrogen peroxide generated by several oxidase system

    OpenAIRE

    劒持,堅志

    1984-01-01

    In vitro oxidation of metallic mercury by catalase and hydrogen peroxide generated by the glucose-glucose oxidase system, D-alanine-D-amino acid oxidase system and xanthine-xanthine oxidase-superoxide dismutase system was investigated. In vitro oxidation of metallic mercury by catalase and hydrogen peroxide generated by the reaction with glucose and glucose oxidase was observed in erythrocytes and crystalline beef liver catalase solution. The uptake depended on the concentration of glucose ox...

  1. Mercury accumulation by lower trophic-level organisms in lentic systems within the Guadalupe River watershed, California

    Science.gov (United States)

    Kuwabara, James S.; Topping, Brent R.; Moon, Gerald E.; Husby, Peter; Lincoff, Andrew; Carter, James L.; Croteau, Marie-Noële

    2005-01-01

    The water columns of four reservoirs (Almaden, Calero, Guadalupe and Lexington Reservoirs) and an abandoned quarry pit filled by Alamitos Creek drainage for recreational purposes (Lake Almaden) were sampled on September 14 and 15, 2004 to provide the first measurements of mercury accumulation by phytoplankton and zooplankton in lentic systems (bodies of standing water, as in lakes and reservoirs) within the Guadalupe River watershed, California. Because of widespread interest in ecosystem effects associated with historic mercury mining within and downgradient of the Guadalupe Riverwatershed, transfer of mercury to lower trophic-level organisms was examined. The propensity of mercury to bioaccumulate, particularly in phytoplankton and zooplankton at the base of the food web, motivated this attempt to provide information in support of developing trophic-transfer and solute-transport models for the watershed, and hence in support of subsequent evaluation of load-allocation strategies. Both total mercury and methylmercury were examined in these organisms. During a single sampling event, replicate samples from the reservoir water column were collected and processed for dissolved-total mercury, dissolved-methylmercury, phytoplankton mercury speciation, phytoplankton taxonomy and biomass, zooplankton mercury speciation, and zooplankton taxonomy and biomass. The timing of this sampling event was coordinated with sampling and analysis of fish from these five water bodies, during a period of the year when vertical stratification in the reservoirs generates a primary source of methylmercury to the watershed. Ancillary data, including dissolved organic carbon and trace-metal concentrations as well as vertical profiles of temperature, dissolved oxygen, specific conductance and pH, were gathered to provide a water-quality framework from which to compare the results for mercury. This work, in support of the Guadalupe River Mercury Total Maximum Daily Load (TMDL) Study, provides

  2. Uniaxial creep as a control on mercury intrusion capillary pressure in consolidating rock salt

    Energy Technology Data Exchange (ETDEWEB)

    Dewers, Thomas [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Heath, Jason E. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Leigh, Christi D. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    The nature of geologic disposal of nuclear waste in salt formations requires validated and verified two - phase flow models of transport of brine and gas through intact, damaged, and consolidating crushed salt. Such models exist in oth er realms of subsurface engineering for other lithologic classes (oil and gas, carbon sequestration etc. for clastics and carbonates) but have never been experimentally validated and parameterized for salt repository scenarios or performance assessment. Mo dels for waste release scenarios in salt back - fill require phenomenological expressions for capillary pressure and relative permeability that are expected to change with degree of consolidation, and require experimental measurement to parameterize and vali date. This report describes a preliminary assessment of the influence of consolidation (i.e. volume strain or porosity) on capillary entry pressure in two phase systems using mercury injection capillary pressure (MICP). This is to both determine the potent ial usefulness of the mercury intrusion porosimetry method, but also to enable a better experimental design for these tests. Salt consolidation experiments are performed using novel titanium oedometers, or uniaxial compression cells often used in soil mech anics, using sieved run - of - mine salt from the Waste Isolation Pilot Plant (WIPP) as starting material. Twelve tests are performed with various starting amounts of brine pore saturation, with axial stresses up to 6.2 MPa (%7E900 psi) and temperatures to 90 o C. This corresponds to UFD Work Package 15SN08180211 milestone "FY:15 Transport Properties of Run - of - Mine Salt Backfill - Unconsolidated to Consolidated". Samples exposed to uniaxial compression undergo time - dependent consolidation, or creep, to various deg rees. Creep volume strain - time relations obey simple log - time behavior through the range of porosities (%7E50 to 2% as measured); creep strain rate increases with temperature and applied stress as

  3. Control of mercury emissions from coal fired electric uitlity boilers: An update

    Science.gov (United States)

    Coal-fired power plants in the U.S. are known to be the major anthropogenic source of domestic mercury emissions. The Environmental Protection Agency (EPA) has recently proposed to reduce emissions of mercury from these plants. In March 2005, EPA plans to promulgate final regulat...

  4. FUNDAMENTALS OF MERCURY SPECIATION AND CONTROL IN COAL-FIRED BOILERS

    Science.gov (United States)

    The report describes the progress of an experimental investigation of the speciation of mercury in simulated coal combustion flue gasses. The effects of flue gas parameters and coal fly ash on the oxidation of elemental mercury (Hgo) in the presence of hydrogen chloride (HCl) in ...

  5. Mercury detection with thermal neutrons

    International Nuclear Information System (INIS)

    Bell, Z.W.

    1994-01-01

    This report describes the work performed to design a gauge to detect mercury concealed within walls, floors, pipes, and equipment inside a building. The project arose out of a desire to decontaminate and decommission (D ampersand D) a building in which mercury had been used as part of a chemical process. The building contains plumbing and equipment, some with residual mercury even after draining, sumps, and hollow walls. So that releases of mercury to the environment might be minimized during D ampersand D activities, it was considered advisable to locate pockets of mercury that may have collected in concealed spaces so that they might be drained in a controlled fashion prior to the application of the wrecking ball or sledge hammer. The detection of such pockets within a building presents some problems not ordinarily encountered in a laboratory environment. Often, only a single side of a wall or pipe is accessible. This condition disqualifies transmission gauges (such as conventional x radiography) in which a probe is sent through the volume under test (VUT) from one side and its passage or attenuation is detected on the opposite side. A robust, one-sided system was needed

  6. Control system design method

    Science.gov (United States)

    Wilson, David G [Tijeras, NM; Robinett, III, Rush D.

    2012-02-21

    A control system design method and concomitant control system comprising representing a physical apparatus to be controlled as a Hamiltonian system, determining elements of the Hamiltonian system representation which are power generators, power dissipators, and power storage devices, analyzing stability and performance of the Hamiltonian system based on the results of the determining step and determining necessary and sufficient conditions for stability of the Hamiltonian system, creating a stable control system based on the results of the analyzing step, and employing the resulting control system to control the physical apparatus.

  7. Pilot Testing of WRI'S Novel Mercury Control Technology by Pre-Combustion Thermal Treatment of Coal

    Energy Technology Data Exchange (ETDEWEB)

    Alan Bland; Jesse Newcomer; Kumar Sellakumar

    2008-08-17

    The challenges to the coal-fired power industry continue to focus on the emission control technologies, such as mercury, and plant efficiency improvements. An alternate approach to post-combustion control of mercury, while improving plant efficiency deals with Western Research Institute's (WRI)'s patented pre-combustion mercury removal and coal upgrading technology. WRI was awarded under the DOE's Phase III Mercury program, to evaluate the effectiveness of WRI's novel thermal pretreatment process to achieve >50% mercury removal, and at costs of <$30,000/lb of Hg removed. WRI has teamed with Etaa Energy, Energy and Environmental Research Center (EERC), Foster Wheeler North America Corp. (FWNA), and Washington Division of URS (WD-URS), and with project co-sponsors including Electric Power Research Institute (EPRI), Southern Company, Basin Electric Power Cooperative (BEPC), Montana-Dakota Utilities (MDU), North Dakota Industrial Commission (NDIC), Detroit Edison (DTE), and SaskPower to undertake this evaluation. The technical objectives of the project were structured in two phases: Phase I--coal selection and characterization, and bench-and PDU-scale WRI process testing and; and Phase II--pilot-scale pc combustion testing, design of an integrated boiler commercial configuration, its impacts on the boiler performance and the economics of the technology related to market applications. This report covers the results of the Phase I testing. The conclusion of the Phase I testing was that the WRI process is a technically viable technology for (1) removing essentially all of the moisture from low rank coals, thereby raising the heating value of the coal by about 30% for subbituminous coals and up to 40% for lignite coals, and (2) for removing volatile trace mercury species (up to 89%) from the coal prior to combustion. The results established that the process meets the goals of DOE of removing <50% of the mercury from the coals by pre-combustion methods

  8. Mercury in the environment : a primer

    Energy Technology Data Exchange (ETDEWEB)

    Lourie, B.; Glenn, W. (ed.); Ogilvie, K.; Everhardus, E.; Friesen, K.; Rae, S.

    2003-06-01

    This report provides an overview of the occurrence and effects of mercury in the environment and its impacts on human health. Low levels of mercury occur naturally everywhere in the environment in plants, animals, rocks and air. Incidental emissions occur when natural mercury is released to the environment through human activity. In Canada, coal burning and metal processing are the two largest point sources of atmospheric mercury emissions. Energy facilities have the option to invest in expensive control technologies for coal plants, or they can generate electricity from alternative energy sources. Energy conservation, however, offers the greatest overall benefits for the environment and the public. Mercury can also be released when products containing mercury (such as electrical switches, thermostats, dental amalgam, and thermometers) are broken while in use, or when they are crushed in garbage trucks and dumped in landfills. Source separation is the best way to reduce waste-related emissions. Once mercury is released to the natural environment, it can be transported long distances through air or watercourses. It is volatile, therefore evaporates readily to the atmosphere where it may do one of three things: it may fall out near the point where it was emitted; it may be transported long distances to some point downwind; or, it may enter the global atmospheric mercury pool where it will circle the globe for a year or more within the Earth's major weather systems before being deposited. Data from Canada's National Pollutant Release Inventory indicates that mercury releases and transfers total 28,674 kg per year. The most critical component of the mercury cycle is the conversion of inorganic forms of mercury to the organic compound methylmercury which is more toxic to humans. Most concern about mercury focuses on lakes and other aquatic ecosystems. Fish in hydroelectric reservoirs have been found to contain elevated methylmercury levels because natural

  9. Global Mercury Assessment 2013

    International Development Research Centre (IDRC) Digital Library (Canada)

    mercury pollution. This summary report and the accompanying. Technical Background Report for the Global. Mercury Assessment 2013 are developed in response to Decision 25/5, paragraph ... The use of different pollution control technologies in different ...... vegetation, snow, freshwater, and seawater. One of the largest ...

  10. Optimization of an in vivo X-ray fluorescence mercury measurement system

    International Nuclear Information System (INIS)

    O'Meara, J.M.; Boerjesson, J.; Chettle, D.R.; McNeill, F.E.

    2004-01-01

    A non-invasive in vivo X-ray fluorescence (XRF) method of measuring renal mercury concentrations has previously been reported, as a potential occupational monitoring tool for those who work with this toxic element [Phys. Med. Biol. 40 (1995) 413]. However, the detection limits remain high compared to the typical values anticipated in these populations. Our approach for further enhancing the XRF renal mercury detection limit has been threefold: investigations of the ideal filtration and tube voltage with a conventional tungsten anode X-ray tube, and the replacement of the existing tungsten X-ray tube with a Fluorex tube [Phys. Med. Biol. 36 (1991) 1573]. In all cases the systems were compared by Monte Carlo simulation to that reported by Boerjesson et al. [Phys. Med. Biol. 40 (1995) 413]. The optimal filtration was found to be a 0.035 cm uranium filter, positioned after the polarizer. Modest improvement was achieved by increasing the tungsten tube voltage from 160 [Phys. Med. Biol. 40 (1995) 413] to 200 kV, decreasing the system detection limit by 27% for the same subject dose. It was found that the Fluorex tube did not improve the system sensitivity for a given dose rate, either when the tube was used for direct excitation or in a polarized configuration. Despite the improved performance reported here at 200 kV, detection limits remain high compared to typical levels in occupationally exposed individuals

  11. Signs and symptoms of mercury-exposed gold miners.

    Science.gov (United States)

    Bose-O'Reilly, Stephan; Bernaudat, Ludovic; Siebert, Uwe; Roider, Gabriele; Nowak, Dennis; Drasch, Gustav

    2017-03-30

    Gold miners use mercury to extract gold from ore adding liquid mercury to the milled gold-containing ore. This results in a mercury-gold compound, called amalgam. Miners smelt this amalgam to obtain gold, vaporizing it and finally inhaling the toxic mercury fumes. The objective was to merge and analyze data from different projects, to identify typical signs and symptoms of chronic inorganic mercury exposure. Miners and community members from various artisanal small-scale gold mining areas had been examined (Philippines, Mongolia, Tanzania, Zimbabwe, Indonesia). Data of several health assessments were pooled. Urine, blood and hair samples were analyzed for mercury (N = 1252). Questionnaires, standardized medical examinations and neuropsychological tests were used. Participants were grouped into: Controls (N = 209), living in an exposed area (N = 408), working with mercury as panners (N = 181), working with mercury as amalgam burners (N = 454). Chi2 test, linear trend test, Mann-Whitney test, Kruskal-Wallis test, correlation coefficient, Spearman's rho, and analysis of variance tests were used. An algorithm was used to define participants with chronic mercury intoxication. Mean mercury concentrations in all exposed subgroups were elevated and above threshold limits, with amalgam burners showing highest levels. Typical symptoms of chronic metallic mercury intoxication were tremor, ataxia, coordination problems, excessive salivation and metallic taste. Participants from the exposed groups showed poorer results in different neuropsychological tests in comparison to the control group. Fifty-four percent of the high-exposed group (amalgam burners) were diagnosed as being mercury-intoxicated, compared to 0% within the control group (Chi2 p mercury intoxication, with tremor, ataxia and other neurological symptoms together with a raised body burden of mercury was clinically diagnosed in exposed people in artisanal small-scale mining areas. The mercury exposure needs to be

  12. Wisdom Appliance Control System

    Science.gov (United States)

    Hendrick; Jheng, Jyun-Teng; Tsai, Chen-Chai; Liou, Jia-Wei; Wang, Zhi-Hao; Jong, Gwo-Jia

    2017-07-01

    Intelligent appliances wisdom involves security, home care, convenient and energy saving, but the home automation system is still one of the core unit, and also using micro-processing electronics technology to centralized and control the home electrical products and systems, such as: lighting, television, fan, air conditioning, stereo, it composed of front-controller systems and back-controller panels, user using front-controller to control command, and then through the back-controller to powered the device.

  13. Emissions of airborne toxics from coal-fired boilers: Mercury

    Energy Technology Data Exchange (ETDEWEB)

    Huang, H.S.; Livengood, C.D.; Zaromb, S.

    1991-09-01

    Concerns over emissions of hazardous air Pollutants (air toxics) have emerged as a major environmental issue, and the authority of the US Environmental Protection Agency to regulate such pollutants was greatly expanded through the Clean Air Act Amendments of 1990. Mercury has been singled out for particular attention because of concerns over possible effects of emissions on human health. This report evaluates available published information on the mercury content of coals mined in the United States, on mercury emitted in coal combustion, and on the efficacy of various environmental control technologies for controlling airborne emissions. Anthracite and bituminous coals have the highest mean-mercury concentrations, with subbituminous coals having the lowest. However, all coal types show very significant variations in mercury concentrations. Mercury emissions from coal combustion are not well-characterized, particularly with regard to determination of specific mercury compounds. Variations in emission rates of more than an order of magnitude have been reported for some boiler types. Data on the capture of mercury by environmental control technologies are available primarily for systems with electrostatic precipitators, where removals of approximately 20% to over 50% have been reported. Reported removals for wet flue-gas-desulfurization systems range between 35 and 95%, while spray-dryer/fabric-filter systems have given removals of 75 to 99% on municipal incinerators. In all cases, better data are needed before any definitive judgments can be made. This report briefly reviews several areas of research that may lead to improvements in mercury control for existing flue-gas-clean-up technologies and summarizes the status of techniques for measuring mercury emissions from combustion sources.

  14. Field Testing of a Wet FGD Additive for Enhanced Mercury Control

    Energy Technology Data Exchange (ETDEWEB)

    Gary Blythe; MariJon Owens

    2007-12-31

    This document is the final report for DOE-NETL Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project has been to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project was intended to demonstrate whether such additives can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project involved pilot- and full-scale tests of the additives in wet FGD absorbers. The tests were intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power provided the Texas lignite/PRB co-fired test site for pilot FGD tests and project cost sharing. Southern Company provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested, and project cost sharing. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation provided the TMT-15 additive, and the Nalco Company provided the Nalco 8034 additive. Both companies also supplied technical support to the test program as in-kind cost sharing. The project was conducted in six tasks. Of the six tasks, Task 1 involved project planning and Task

  15. Transits in our Solar System for educational activities: Mercury Transit 2016 and Total Solar Eclipse 2017

    Science.gov (United States)

    Pérez-Ayúcar, M.; Breitfelner, M.

    2017-09-01

    Solar transits are rare astronomical event of profound historical importance and with an enormous potential to engage nowadays students and general public into Planetary Sciences and Space. Mercury transits occur only about every 13-14 times per century. Total solar eclipses occur around 18 months apart somewhere on Earth, but they recur only every 3-4 centuries on the same location. Although its historic scientific importance (examples, to measure the distances in the solar system, to observe the solar corona) has diminished since humanity roams our solar system with robotic spacecrafts, transits remain a spectacular astronomical event that is used very effectively to engage general public and students to Science and Space in general. The educational project CESAR (Cooperation through Education in Science and Astronomy Research) has been covering since 2012 such events (Venus transit 2012, live Sun transmissions, solar eclipses, ISS transits ...). We report the outstanding outcome of the two public educational and outreach events since last year: the May 2016 Mercury Transit, and the recent August 2017 Total Eclipse. And the follow up activities expected for future transits.

  16. Mercury in Hair Is Inversely Related to Disease Associated Damage in Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    William Crowe

    2015-12-01

    Full Text Available Systemic lupus erythematosus (SLE is an autoimmune inflammatory disease, and environmental factors are proposed to exacerbate existing symptoms. One such environmental factor is mercury. The aim of this study was to investigate the relationship between exposure to mercury (Hg and disease activity and disease associated damage in Total Hg concentrations in hair and urine were measured in 52 SLE patients. Dental amalgams were quantified. Disease activity was assessed using three indexes including the British Isles Lupus Assessment Group Index (BILAG. Disease associated damage was measured using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology SLICC/ACR Damage Index. Pearson’s correlation identified a significant negative correlation between hair Hg and BILAG (r = −0.323, p = 0.029 and SLICC/ACR (r = −0.377, p = 0.038. Multiple regression analysis identified hair Hg as a significant predictor of disease associated damage as determined by SLICC/ACR (β = −0.366, 95% confidence interval (CI: −1.769, −0.155 p = 0.019. Urinary Hg was not related to disease activity or damage. Fish consumption is the primary route of MeHg exposure in humans and the inverse association of hair Hg with disease activity observed here might be explained by the anti-inflammatory effects of n-3 long chain polyunsaturated fatty acids also found in fish.

  17. Development of a Ground-Based Atmospheric Monitoring Network for the Global Mercury Observation System (GMOS

    Directory of Open Access Journals (Sweden)

    Sprovieri F.

    2013-04-01

    Full Text Available Consistent, high-quality measurements of atmospheric mercury (Hg are necessary in order to better understand Hg emissions, transport, and deposition on a global scale. Although the number of atmospheric Hg monitoring stations has increased in recent years, the available measurement database is limited and there are many regions of the world where measurements have not been extensively performed. Long-term atmospheric Hg monitoring and additional ground-based monitoring sites are needed in order to generate datasets that will offer new insight and information about the global scale trends of atmospheric Hg emissions and deposition. In the framework of the Global Mercury Observation System (GMOS project, a coordinated global observational network for atmospheric Hg is being established. The overall research strategy of GMOS is to develop a state-of-the-art observation system able to provide information on the concentration of Hg species in ambient air and precipitation on the global scale. This network is being developed by integrating previously established ground-based atmospheric Hg monitoring stations with newly established GMOS sites that are located both at high altitude and sea level locations, as well as in climatically diverse regions. Through the collection of consistent, high-quality atmospheric Hg measurement data, we seek to create a comprehensive assessment of atmospheric Hg concentrations and their dependence on meteorology, long-range atmospheric transport and atmospheric emissions.

  18. Alteration of the spontaneous systemic autoimmune disease in (NZB x NZW)F1 mice by treatment with thimerosal (ethyl mercury)

    International Nuclear Information System (INIS)

    Havarinasab, S.; Hultman, P.

    2006-01-01

    Inorganic mercury may aggravate murine systemic autoimmune diseases which are either spontaneous (genetically determined) or induced by non-genetic mechanisms. Organic mercury species, the dominating form of mercury exposure in the human population, have not been examined in this respect. Therefore, ethyl mercury in the form of thimerosal, a preservative recently debated as a possible health hazard when present in vaccines, was administered in a dose of 0.156-5 mg/L drinking water to female (NZB x NZW)F1 (ZBWF1) mice. These mice develop an age-dependent spontaneous systemic autoimmune disease with high mortality primarily due to immune-complex (IC) glomerulonephritis. Five mg thimerosal/L drinking water (295 μg Hg/kg body weight (bw)/day) for 7 weeks induced glomerular, mesangial and systemic vessel wall IC deposits and antinuclear antibodies (ANA) which were not present in the untreated controls. After 22-25 weeks, the higher doses of thimerosal had shifted the localization of the spontaneously developing renal glomerular IC deposits from the capillary wall position seen in controls to the mesangium. The altered localization was associated with less severe histological kidney damage, less proteinuria, and reduced mortality. The effect was dose-dependent, lower doses having no effect compared with the untreated controls. A different effect of thimerosal treatment was induction of renal and splenic vessel walls IC deposits. Renal vessel wall deposits occurred at a dose of 0.313-5 mg thimerosal/L (18-295 μg Hg/kg bw/day), while splenic vessel wall deposits developed also in mice given the lowest dose of thimerosal, 0.156 mg/L (9 μg Hg/kg bw/day). The latter dose is 3- and 15-fold lower than the dose of Hg required to induce vessel wall IC deposits in genetically susceptible H-2 s mice by HgCl 2 and thimerosal, respectively. Further studies on the exact conditions needed for induction of systemic IC deposits by low-dose organic mercurials in autoimmune

  19. Meeting Minamata: Cost-effective compliance options for atmospheric mercury control in Chinese coal-fired power plants

    International Nuclear Information System (INIS)

    Ancora, Maria Pia; Zhang, Lei; Wang, Shuxiao; Schreifels, Jeremy J.; Hao, Jiming

    2016-01-01

    A new international treaty, Minamata Convention, identifies mercury (Hg) as a global threat to human health and seeks to control its releases and emissions. Coal-fired power plants are a major source of mercury pollution worldwide and are expected to be the first key sector to be addressed in China under Minamata Convention. A best available technique (BAT) adoption model was developed in the form of a decision tree and cost-effectiveness for each technological option. Co-benefit control technologies and their enhancement with coal blending/switching and halogen injection (HI) can provide early measures to help China meet the Minamata Convention obligations. We project future energy and policy scenarios to simulate potential national mercury reduction goals for China and estimate costs of the control measures for each scenario. The “Minamata Medium” scenario, equivalent to the goal of the US Mercury and Air Toxics Standards (MATS) rule, requires the application of activated carbon injection (ACI) and HI on 30% and 20% of power plants, respectively. The corresponding total costs would be $2.5 billion, approximately one-fourth the costs in the US. An emission limit of 3 µg/m 3 in 2030 was identified as a feasible policy option for China to comply with Minamata Convention. - Highlights: • First Minamata Convention compliance toolset for coal-fired power plants in China. • BAT decision tree regarding the most comprehensive set of Hg control technologies. • Co-benefit Hg control technology and its enhancement could be early measures. • ACI and HI application needed for China to reproduce the goal of MATS in the US. • Policy options on Hg emission reduction targets achievable at reasonable costs.

  20. Personal exposure control system

    International Nuclear Information System (INIS)

    Tanabe, Ken-ichi; Akashi, Michio

    1994-01-01

    Nuclear power stations are under strict radiation control. Exposure control for nuclear workers is the most important operation, and so carefully thought out measures are taken. This paper introduces Fuji Electric's personal exposure control system that meets strict exposure control and rationalizes control operations. The system has a merit that it can provide required information in an optimum form using the interconnection of a super minicomputer and exposure control facilities and realizes sophisticated exposure control operations. (author)

  1. Mercury isotope signatures of seawater discharged from a coal-fired power plant equipped with a seawater flue gas desulfurization system.

    Science.gov (United States)

    Lin, Haiying; Peng, Jingji; Yuan, Dongxing; Lu, Bingyan; Lin, Kunning; Huang, Shuyuan

    2016-07-01

    Seawater flue gas desulfurization (SFGD) systems are commonly used to remove acidic SO2 from the flue gas with alkaline seawater in many coastal coal-fired power plants in China. However, large amount of mercury (Hg) originated from coal is also transferred into seawater during the desulfurization (De-SO2) process. This research investigated Hg isotopes in seawater discharged from a coastal plant equipped with a SFGD system for the first time. Suspended particles of inorganic minerals, carbon residuals and sulfides are enriched in heavy Hg isotopes during the De-SO2 process. δ(202)Hg of particulate mercury (PHg) gradually decreased from -0.30‰ to -1.53‰ in study sea area as the distance from the point of discharge increased. The results revealed that physical mixing of contaminated De-SO2 seawater and uncontaminated fresh seawater caused a change in isotopic composition of PHg isotopes in the discharging area; and suggested that both De-SO2 seawater and local background contributed to PHg. The impacted sea area predicted with isotopic tracing technique was much larger than that resulted from a simple comparison of pollutant concentration. It was the first attempt to apply mercury isotopic composition signatures with two-component mixing model to trace the mercury pollution and its influence in seawater. The results could be beneficial to the coal-fired plants with SFGD systems to assess and control Hg pollution in sea area. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Interpretation of the source-specific substantive control measures of the Minamata Convention on Mercury.

    Science.gov (United States)

    You, Mingqing

    2015-02-01

    Being persistent, toxic, and bio-accumulative, Mercury (Hg) seriously affects the environment and human health. Due to Hg's attribute of long-range environmental transport across national borders, especially through atmospheric transport, no country can fully protect its environment and human health with its own efforts, without global cooperation. The Minamata Convention on Mercury, which was formally adopted and opened for signature in October 2013, is the only global environmental regime on the control of Hg pollution. Its main substantive control measures are source-specific: its phasing-out, phasing-down, and other main substantive requirements all direct to specific categories of pollution sources through the regulation of specific sectors of the economy and social life. This Convention does not take a national quota approach to quantify the Parties' nationwide total allowable consumption or discharge of Hg or Hg compounds, nor does it quantify their nationwide total reduction requirements. This paper attempts to find the underlying reasons for this source-specific approach and offers two interpretations. One possible interpretation is that Hg might be a non-threshold pollutant, i.e., a pollutant without a risk-free value of concentration. The existence of a reference dose (RfD), reference concentration (RfC), provisional tolerable weekly intake (PTWI), minimal risk level (MRL) or other similar reference values of Hg does not necessarily mean that Hg cannot be regarded as non-threshold because such reference values have scientific uncertainties and may also involve policy considerations. Another interpretation is that Hg lacks a feasibly determinable total allowable quantity. There is evidence that negotiators might have treated Hg as non-threshold, or at least accepted that Hg lacks a feasibly determinable total allowable quantity: (1) The negotiators were informed about the serious situations of the current emissions, releases, and legacy deposition; (2

  3. Emissions, Monitoring, and Control of Mercury from Subbituminous Coal-Fired Power Plants - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Alan Bland; Jesse Newcomer; Allen Kephart; Volker Schmidt; Gerald Butcher

    2008-10-31

    Western Research Institute (WRI), in conjunction with Western Farmers Electric Cooperative (WFEC), has teamed with Clean Air Engineering of Pittsburgh PA to conduct a mercury monitoring program at the WEFC Hugo plant in Oklahoma. Sponsored by US Department of Energy Cooperative Agreement DE-FC-26-98FT40323, the program included the following members of the Subbituminous Energy Coalition (SEC) as co-sponsors: Missouri Basin Power Project; DTE Energy; Entergy; Grand River Dam Authority; and Nebraska Public Power District. This research effort had five objectives: (1) determine the mass balance of mercury for subbituminous coal-fired power plant; (2) assess the distribution of mercury species in the flue gas (3) perform a comparison of three different Hg test methods; (4) investigate the long-term (six months) mercury variability at a subbituminous coal-fired power plant; and (5) assess operation and maintenance of the Method 324 and Horiba CEMS utilizing plant personnel.

  4. Method for the removal and recovery of mercury

    Science.gov (United States)

    Easterly, Clay E.; Vass, Arpad A.; Tyndall, Richard L.

    1997-01-01

    The present invention is an enhanced method for the removal and recovery of mercury from mercury-contaminated matrices. The method involves contacting a mercury-contaminated matrix with an aqueous dispersant solution derived from specific intra-amoebic isolates to release the mercury from the mercury-contaminated matrix and emulsify the mercury; then, contacting the matrix with an amalgamating metal from a metal source to amalgamate the mercury to the amalgamating metal; removing the metallic source from the mercury-contaminated matrix; and heating the metallic source to vaporize the mercury in a closed system to capture the mercury vapors.

  5. The remote control system

    International Nuclear Information System (INIS)

    Jansweijer, P.P.M.

    1988-01-01

    The remote-control system is applied in order to control various signals in the car of the spectrometer at distance. The construction (hardware and software) as well as the operation of the system is described. (author). 20 figs

  6. Control and automation systems

    International Nuclear Information System (INIS)

    Schmidt, R.; Zillich, H.

    1986-01-01

    A survey is given of the development of control and automation systems for energy uses. General remarks about control and automation schemes are followed by a description of modern process control systems along with process control processes as such. After discussing the particular process control requirements of nuclear power plants the paper deals with the reliability and availability of process control systems and refers to computerized simulation processes. The subsequent paragraphs are dedicated to descriptions of the operating floor, ergonomic conditions, existing systems, flue gas desulfurization systems, the electromagnetic influences on digital circuits as well as of light wave uses. (HAG) [de

  7. Soil geochemistry and digestive solubilization control mercury bioaccumulation in the earthworm Pheretima guillemi.

    Science.gov (United States)

    Dang, Fei; Zhao, Jie; Greenfield, Ben K; Zhong, Huan; Wang, Yujun; Yang, Zhousheng; Zhou, Dongmei

    2015-07-15

    Mercury presents a potential risk to soil organisms, yet our understanding of mercury bioaccumulation in soil dwelling organisms is limited. The influence of soil geochemistry and digestive processes on both methylmercury (MeHg) and total mercury (THg) bioavailability to earthworms (Pheretima guillemi) was evaluated in this study. Earthworms were exposed to six mercury-contaminated soils with geochemically contrasting properties for 36 days, and digestive fluid was concurrently collected to solubilize soil-associated mercury. Bioaccumulation factors were 7.5-31.0 and 0.2-0.6 for MeHg and THg, respectively, and MeHg accounted for 17-58% of THg in earthworm. THg and MeHg measured in soils and earthworms were negatively associated with soil total organic carbon (TOC). Earthworm THg and MeHg also increased with increasing soil pH. The proportion of MeHg and THg released into the digestive fluid (digestive solubilizable mercury, DSM) was 8.3-18.1% and 0.4-1.3%, respectively. The greater solubilization of MeHg by digestive fluid than CaCl2, together with a biokinetic model-based estimate of dietary MeHg uptake, indicated the importance of soil ingestion for MeHg bioaccumulation in earthworms. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Distributed System Control

    National Research Council Canada - National Science Library

    Berea, James

    1997-01-01

    Global control in distributed systems had not been well researched. Control had only been addressed in a limited manner, such as for data-update consistency in distributed, redundant databases or for confidentiality controls...

  9. FINANCIAL CONTROL SYSTEM IMPROVEMENT

    OpenAIRE

    L. V. Kurmaeva

    2012-01-01

    Forms and methods of external and internal financial control are discussed. The system of the state and municipal financial control in Russia is described. Changes to organization of internal financial control and audit are proposed.

  10. Sorption Mechanisms for Mercury Capture in Warm Post-Gasification Gas Clean-Up Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jost Wendt; Sung Jun Lee; Paul Blowers

    2008-09-30

    The research was directed towards a sorbent injection/particle removal process where a sorbent may be injected upstream of the warm gas cleanup system to scavenge Hg and other trace metals, and removed (with the metals) within the warm gas cleanup process. The specific objectives of this project were to understand and quantify, through fundamentally based models, mechanisms of interaction between mercury vapor compounds and novel paper waste derived (kaolinite + calcium based) sorbents (currently marketed under the trade name MinPlus). The portion of the research described first is the experimental portion, in which sorbent effectiveness to scavenge metallic mercury (Hg{sup 0}) at high temperatures (>600 C) is determined as a function of temperature, sorbent loading, gas composition, and other important parameters. Levels of Hg{sup 0} investigated were in an industrially relevant range ({approx} 25 {micro}g/m{sup 3}) although contaminants were contained in synthetic gases and not in actual flue gases. A later section of this report contains the results of the complementary computational results.

  11. Dynamics of control systems

    Science.gov (United States)

    Zubov, V. I.

    Papers are presented on mathematical methods for the analysis of control systems for technical plants and manufacturing processes. Particular attention is given to the mechanics of controlled space flight, the design of automatic control systems, flexible automated complexes, control applications in biomedical research, and chemical technology for the production of new types of materials.

  12. Environmental Assessment for Toxecon Retrofit for Mercury and Multi-Pollutant Control, Presque Isle Power Plant, Marquette, Michigan

    Energy Technology Data Exchange (ETDEWEB)

    N/A

    2003-09-25

    This Environmental Assessment (EA) evaluates environmental issues associated with constructing and operating an integrated emissions control system proposed by We Energies and its project partners with cost-shared funding support by DOE. The proposed project would be demonstrated at the existing 90-MW Units 7, 8, and 9 of We Energies' coal-fired Presque Isle Power Plant in Marquette, Michigan. The commercial-scale demonstrate would allow utilities to make decisions regarding the integrated emissions control system as a viable commercial option. DOE's share of the funding for the 5-year demonstration project would be about $25 million, while $25 million would also be provided by We Energies and its project partners. This project was selected by DOE under the Clean Coal Power Initiative (CCPI) for negotiation of a cooperative agreement to demonstrate the integration of technologies to reduce emissions of mercury (Hg) and particulate matter, as well as potentially control sulfur dioxide (SO{sub 2}), oxides of nitrogen (NO{sub x}) and hydrochloric acid (HCl) emissions. DOE's decision is whether or not to fund the project. The EA evaluates the principal environmental issues, including air quality, waste management, and traffic, that could result from construction and operation of the proposed project. The EA also considers two reasonably foreseeable scenarios that could result from the no-action alternative in which DOE would not provide cost-shared funding for the proposed project. Key findings include that potential air quality impacts resulting from the proposed project would generally be beneficial because plantwide air emissions would decrease or continue at the same level. The decrease in stack exit temperature would decrease the plume rise, which could result in increased downwind ground-level concentrations of those air pollutants experience little or no decrease in stack emissions. However, results of air dispersion modeling indicated that no

  13. Radiative forcing associated with particulate carbon emissions resulting from the use of mercury control technology.

    Science.gov (United States)

    Lin, Guangxing; Penner, Joyce E; Clack, Herek L

    2014-09-02

    Injection of powdered activated carbon (PAC) adsorbents into the flue gas of coal fired power plants with electrostatic precipitators (ESPs) is the most mature technology to control mercury emissions for coal combustion. However, the PAC itself can penetrate ESPs to emit into the atmosphere. These emitted PACs have similar size and optical properties to submicron black carbon (BC) and thus could increase BC radiative forcing unintentionally. The present paper estimates, for the first time, the potential emission of PAC together with their climate forcing. The global average maximum potential emissions of PAC is 98.4 Gg/yr for the year 2030, arising from the assumed adoption of the maximum potential PAC injection technology, the minimum collection efficiency, and the maximum PAC injection rate. These emissions cause a global warming of 2.10 mW m(-2) at the top of atmosphere and a cooling of -2.96 mW m(-2) at the surface. This warming represents about 2% of the warming that is caused by BC from direct fossil fuel burning and 0.86% of the warming associated with CO2 emissions from coal burning in power plants. Its warming is 8 times more efficient than the emitted CO2 as measured by the 20-year-integrated radiative forcing per unit of carbon input (the 20-year Global Warming Potential).

  14. Reactor control system. PWR

    International Nuclear Information System (INIS)

    2009-01-01

    At present, 23 units of PWR type reactors have been operated in Japan since the start of Mihama Unit 1 operation in 1970 and various improvements have been made to upgrade operability of power stations as well as reliability and safety of power plants. As the share of nuclear power increases, further improvements of operating performance such as load following capability will be requested for power stations with more reliable and safer operation. This article outlined the reactor control system of PWR type reactors and described the control performance of power plants realized with those systems. The PWR control system is characterized that the turbine power is automatic or manually controlled with request of the electric power system and then the nuclear power is followingly controlled with the change of core reactivity. The system mainly consists of reactor automatic control system (control rod control system), pressurizer pressure control system, pressurizer water level control system, steam generator water level control system and turbine bypass control system. (T. Tanaka)

  15. Removal of Elemental Mercury from a Gas Stream Facilitated by a Non-Thermal Plasma Device

    Energy Technology Data Exchange (ETDEWEB)

    Charles Mones

    2006-12-01

    Mercury generated from anthropogenic sources presents a difficult environmental problem. In comparison to other toxic metals, mercury has a low vaporization temperature. Mercury and mercury compounds are highly toxic, and organic forms such as methyl mercury can be bio-accumulated. Exposure pathways include inhalation and transport to surface waters. Mercury poisoning can result in both acute and chronic effects. Most commonly, chronic exposure to mercury vapor affects the central nervous system and brain, resulting in neurological damage. The CRE technology employs a series of non-thermal, plasma-jet devices to provide a method for elemental mercury removal from a gas phase by targeting relevant chemical reactions. The technology couples the known chemistry of converting elemental mercury to ionic compounds by mercury-chlorine-oxygen reactions with the generation of highly reactive species in a non-thermal, atmospheric, plasma device. The generation of highly reactive metastable species in a non-thermal plasma device is well known. The introduction of plasma using a jet-injection device provides a means to contact highly reactive species with elemental mercury in a manner to overcome the kinetic and mass-transfer limitations encountered by previous researchers. To demonstrate this technology, WRI has constructed a plasma test facility that includes plasma reactors capable of using up to four plasma jets, flow control instrumentation, an integrated control panel to operate the facility, a mercury generation system that employs a temperature controlled oven and permeation tube, combustible and mercury gas analyzers, and a ductless fume hood designed to capture fugitive mercury emissions. Continental Research and Engineering (CR&E) and Western Research Institute (WRI) successfully demonstrated that non-thermal plasma containing oxygen and chlorine-oxygen reagents could completely convert elemental mercury to an ionic form. These results demonstrate potential the

  16. Mercury and Your Health

    Science.gov (United States)

    ... the Risk of Exposure to Mercury Learn About Mercury What is Mercury What is Metallic mercury? Toxicological Profile ToxFAQs Mercury Resources CDC’s National Biomonitoring Program Factsheet on Mercury ...

  17. Modeling Mercury in Proteins

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jeremy C [ORNL; Parks, Jerry M [ORNL

    2016-01-01

    Mercury (Hg) is a naturally occurring element that is released into the biosphere both by natural processes and anthropogenic activities. Although its reduced, elemental form Hg(0) is relatively non-toxic, other forms such as Hg2+ and, in particular, its methylated form, methylmercury, are toxic, with deleterious effects on both ecosystems and humans. Microorganisms play important roles in the transformation of mercury in the environment. Inorganic Hg2+ can be methylated by certain bacteria and archaea to form methylmercury. Conversely, bacteria also demethylate methylmercury and reduce Hg2+ to relatively inert Hg(0). Transformations and toxicity occur as a result of mercury interacting with various proteins. Clearly, then, understanding the toxic effects of mercury and its cycling in the environment requires characterization of these interactions. Computational approaches are ideally suited to studies of mercury in proteins because they can provide a detailed picture and circumvent issues associated with toxicity. Here we describe computational methods for investigating and characterizing how mercury binds to proteins, how inter- and intra-protein transfer of mercury is orchestrated in biological systems, and how chemical reactions in proteins transform the metal. We describe quantum chemical analyses of aqueous Hg(II), which reveal critical factors that determine ligand binding propensities. We then provide a perspective on how we used chemical reasoning to discover how microorganisms methylate mercury. We also highlight our combined computational and experimental studies of the proteins and enzymes of the mer operon, a suite of genes that confers mercury resistance in many bacteria. Lastly, we place work on mercury in proteins in the context of what is needed for a comprehensive multi-scale model of environmental mercury cycling.

  18. Controlling Mercury Release from Source Zones to Surface Water: Initial Results of Pilot Tests at the Y-12 National Security Complex

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, George R [ORNL; Brooks, Scott C [ORNL; Peterson, Mark J [ORNL; Bogle, Mary Anna [ORNL; Miller, Carrie L [ORNL; Liang, Liyuan [ORNL; Elliott, Mike [Y-12 National Security Complex

    2009-01-01

    This report presents initial results obtained during year 2008 and satisfies a deliverable listed in the work breakdown structure (WBS) element OR081301. Broad objectives of the multi-year project are: (1) evaluation of remediation technologies for waterborne mercury, (2) development of treatment methods for soil mercury, and (3) source identification, characterization and analyses to improve mass balance on mercury estimates. This report presents the results of pilot tests, conducted in summer and fall 2008, which focused on remediation of waterborne mercury. The goal of this task is to develop strategies and treatment technologies that reduce the concentration and loading of waterborne mercury discharges to the UEFPC, thus minimizing mercury uptake by fish. The two specific studies are: (1) reducing flow augmentation in UEFPC to lessen mercury mobilization from contaminated stream sediments, and (2) treatment of contaminated source waters with a chemical reductant to convert dissolved mercury to a volatile form that can be removed by air stripping or natural evasion. Diversion of 50% of the flow currently added to UEFPC by the flow management system appeared to reduce mercury inputs from a localized, highly contaminated streambed by 0.6-1.5 grams per day (g/d). A reduction of 0.6 g/d represents {approx} 7-10% decrease in mercury input to UEFPC. Mercury concentrations within UEFPC did not rise proportionately with the loss of dilution, in part because of the reduction in input from the streambed source and in part because of reduced flow from the Y-12 NSC storm drain system. A longer-term test that includes seasonal variability will be the next step to validate these initial field observations of the flow diversion experiment. Preliminary laboratory experiments show that a large fraction ({approx} 90%) of the mercury can be chemically reduced to Hg(0) by addition of low concentrations of tin, Sn(II). Conversion of mercury to volatile Hg(0) in UEFPC was also

  19. Field Testing of Activated Carbon Injection Options for Mercury Control at TXU's Big Brown Station

    Energy Technology Data Exchange (ETDEWEB)

    John Pavlish; Jeffrey Thompson; Christopher Martin; Mark Musich; Lucinda Hamre

    2009-01-07

    The primary objective of the project was to evaluate the long-term feasibility of using activated carbon injection (ACI) options to effectively reduce mercury emissions from Texas electric generation plants in which a blend of lignite and subbituminous coal is fired. Field testing of ACI options was performed on one-quarter of Unit 2 at TXU's Big Brown Steam Electric Station. Unit 2 has a design output of 600 MW and burns a blend of 70% Texas Gulf Coast lignite and 30% subbituminous Powder River Basin coal. Big Brown employs a COHPAC configuration, i.e., high air-to-cloth baghouses following cold-side electrostatic precipitators (ESPs), for particulate control. When sorbent injection is added between the ESP and the baghouse, the combined technology is referred to as TOXECON{trademark} and is patented by the Electric Power Research Institute in the United States. Key benefits of the TOXECON configuration include better mass transfer characteristics of a fabric filter compared to an ESP for mercury capture and contamination of only a small percentage of the fly ash with AC. The field testing consisted of a baseline sampling period, a parametric screening of three sorbent injection options, and a month long test with a single mercury control technology. During the baseline sampling, native mercury removal was observed to be less than 10%. Parametric testing was conducted for three sorbent injection options: injection of standard AC alone; injection of an EERC sorbent enhancement additive, SEA4, with ACI; and injection of an EERC enhanced AC. Injection rates were determined for all of the options to achieve the minimum target of 55% mercury removal as well as for higher removals approaching 90%. Some of the higher injection rates were not sustainable because of increased differential pressure across the test baghouse module. After completion of the parametric testing, a month long test was conducted using the enhanced AC at a nominal rate of 1.5 lb/Macf. During

  20. Key Contributors to Variations in Fish Mercury Within and Among Freshwater Reservoirs in Oklahoma, USA

    OpenAIRE

    Dong, Zhao; Lynch, Robert A.; Schaider, Laurel A.

    2016-01-01

    Elevated fish mercury (Hg) concentrations in freshwater ecosystems worldwide are a significant human and ecological health concern. Mercury bioaccumulation and biomagnification in lakes and reservoirs are controlled by numerous biogeochemical and ecological factors, contributing to variability in fish Hg concentrations both within and among systems. We measured total mercury concentrations ([THg]) and stable isotopes (δ15N, δ13C) in over 30 fish species in two connected subtropical freshwater...

  1. Mercury and Air Toxic Element Impacts of Coal Combustion By-Product Disposal and Utilizaton

    Energy Technology Data Exchange (ETDEWEB)

    David Hassett; Loreal Heebink; Debra Pflughoeft-Hassett; Tera Buckley; Erick Zacher; Mei Xin; Mae Sexauer Gustin; Rob Jung

    2007-03-31

    The University of North Dakota Energy & Environmental Research Center (EERC) conducted a multiyear study to evaluate the impact of mercury and other air toxic elements (ATEs) on the management of coal combustion by-products (CCBs). The ATEs evaluated in this project were arsenic, cadmium, chromium, lead, nickel, and selenium. The study included laboratory tasks to develop measurement techniques for mercury and ATE releases, sample characterization, and release experiments. A field task was also performed to measure mercury releases at a field site. Samples of fly ash and flue gas desulfurization (FGD) materials were collected preferentially from full-scale coal-fired power plants operating both without and with mercury control technologies in place. In some cases, samples from pilot- and bench-scale emission control tests were included in the laboratory studies. Several sets of 'paired' baseline and test fly ash and FGD materials collected during full-scale mercury emission control tests were also included in laboratory evaluations. Samples from mercury emission control tests all contained activated carbon (AC) and some also incorporated a sorbent-enhancing agent (EA). Laboratory release experiments focused on measuring releases of mercury under conditions designed to simulate CCB exposure to water, ambient-temperature air, elevated temperatures, and microbes in both wet and dry conditions. Results of laboratory evaluations indicated that: (1) Mercury and sometimes selenium are collected with AC used for mercury emission control and, therefore, present at higher concentrations than samples collected without mercury emission controls present. (2) Mercury is stable on CCBs collected from systems both without and with mercury emission controls present under most conditions tested, with the exception of vapor-phase releases of mercury exposed to elevated temperatures. (3) The presence of carbon either from added AC or from unburned coal can result in mercury

  2. Mercury, lead, and zinc in baby teeth of children with autism versus controls.

    Science.gov (United States)

    Adams, James B; Romdalvik, Jane; Ramanujam, V M Sadagopa; Legator, Marvin S

    2007-06-01

    This study determined the level of mercury, lead, and zinc in baby teeth of children with autism spectrum disorder (n = 15, age 6.1 +/- 2.2 yr) and typically developing children (n = 11, age = 7 +/- 1.7 yr). Children with autism had significantly (2.1-fold) higher levels of mercury but similar levels of lead and similar levels of zinc. Children with autism also had significantly higher usage of oral antibiotics during their first 12 mo of life, and possibly higher usage of oral antibiotics during their first 36 mo of life. Baby teeth are a good measure of cumulative exposure to toxic metals during fetal development and early infancy, so this study suggests that children with autism had a higher body burden of mercury during fetal/infant development. Antibiotic use is known to almost completely inhibit excretion of mercury in rats due to alteration of gut flora. Thus, higher use of oral antibiotics in the children with autism may have reduced their ability to excrete mercury, and hence may partially explain the higher level in baby teeth. Higher usage of oral antibiotics in infancy may also partially explain the high incidence of chronic gastrointestinal problems in individuals with autism.

  3. Controls on stream water dissolved mercury in three mid-Appalachian forested headwater catchments

    Science.gov (United States)

    Riscassi, Ami L.; Scanlon, Todd M.

    2011-12-01

    Determining the controls on dissolved mercury (HgD) transport is necessary to improve estimations of export from unmonitored watersheds and to forecast responses to changes in deposition and other environmental forcings. Stream water HgD and dissolved organic carbon (DOC) were evaluated over a range of discharge conditions in three streams within Shenandoah National Park, VA. Watersheds are distinguished by stream water pH (ranging from neutral to acidic) and soil size fractioning (ranging from clays to sands). At all sites, discharge was a significant but poor predictor of HgD concentrations (r2 from 0.13-0.52). HgD was strongly coupled with DOC at all sites (r2 from 0.74-0.89). UV absorbance at 254 nm (UV254), a proxy for DOC quantity and quality, slightly improved the predictions of HgD. Mean DOC quality differed between streams, with less aromatic DOC mobilized from the more acidic watershed. The site with less aromatic DOC and sandy soils mobilized more Hg to the stream for the same quantity and quality of DOC, likely due to the reduced capacity of the larger-grained soils to retain Hg, leaving a greater fraction associated with the organic matter. A similar amount of 0.54 ng HgD/mg DOC is transported at all sites, suggesting the less aromatic DOC transports less Hg per unit DOC, offsetting the effects of soil type. This research demonstrates that soil composition and DOC quality influence HgDexport. We also provide evidence that soil organic carbon is a primary control on Hg-DOC ratios (0.12-1.4 ng mg-1) observed across the U.S. and Sweden.

  4. Intelligent control systems 1990

    International Nuclear Information System (INIS)

    Shoureshi, R.

    1991-01-01

    The field of artificial intelligence (Al) has generated many useful ideas and techniques that can be integrated into the design of control systems. It is believed and, for special cases, has been demonstrated, that integration of Al into control systems would provide the necessary tools for solving many of the complex problems that present control techniques and Al algorithms are unable to do, individually. However, this integration requires the development of basic understanding and new fundamentals to provide scientific bases for achievement of its potential. This book presents an overview of some of the latest research studies in the area of intelligent control systems. These papers present techniques for formulation of intelligent control, and development of the rule-based control systems. Papers present applications of control systems in nuclear power plants and HVAC systems

  5. Study on the mercury evolution in a laboratory multi specific aquatic system by using instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Bubach, Debora; Guevara, Sergio Ribeiro; Arribere, Maria A.; Pechen de d'Angelo, Ana; Ferrari, Ana; Venturino, Andres

    1999-01-01

    A preliminary study on the evolution of mercury in the organisms of a laboratory multi specific aquatic system was performed using Instrumental Neutron Activation Analysis (INAA). Some of the possible effects of mercury toxicity were monitored by analyzing early biochemical indicators. The system consisted of an aquarium with bed sediments, aquatic macrophytes (Myriophyllum sp.), bivalves (Diplodom sp.) and exotic fish, simulating a long term contamination situation of unknown causes, where the sediments are the contaminant reservoir. Samples of the abiotic components of the system were analyzed at the beginning of the experiment, and again when the organisms were sampled. Fish carcass, kidney and liver samples, bivalve hepatopancreas, and whole macrophytes were extracted ana analyzed for mercury and other elements by INAA at the beginning of the experiment, and after 48 and 96 hours. Since some crustal elements such as Sc and La were detected in the hepatopancreas and macrophyte samples, enrichment factors for mercury, with respect to the <63 μm sediment fraction, were computed to discriminate the metabolized Hg content from that associated to the particulate. The hepatopancreas index, some indicators of oxidative stress (γ-Glutamyl-cysteinyl-glycine content and lipid peroxidation) and brain acetilcolinesterasa were measured as early indicators of toxicity. (author)

  6. MESSENGER: Exploring Mercury's Magnetosphere

    Science.gov (United States)

    Slavin, James A.

    2008-01-01

    The MESSENGER mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since Mariner 10's brief fly-bys in 1974-5. Mercury's magnetosphere is unique in many respects. The magnetosphere of Mercury is the smallest in the solar system with its magnetic field typically standing off the solar wind only - 1000 to 2000 km above the surface. For this reason there are no closed dri-fi paths for energetic particles and, hence, no radiation belts; the characteristic time scales for wave propagation and convective transport are short possibly coupling kinetic and fluid modes; magnetic reconnection at the dayside magnetopause may erode the subsolar magnetosphere allowing solar wind ions to directly impact the dayside regolith; inductive currents in Mercury's interior should act to modify the solar In addition, Mercury's magnetosphere is the only one with its defining magnetic flux tubes rooted in a planetary regolith as opposed to an atmosphere with a conductive ionosphere. This lack of an ionosphere is thought to be the underlying reason for the brevity of the very intense, but short lived, approx. 1-2 min, substorm-like energetic particle events observed by Mariner 10 in Mercury's magnetic tail. In this seminar, we review what we think we know about Mercury's magnetosphere and describe the MESSENGER science team's strategy for obtaining answers to the outstanding science questions surrounding the interaction of the solar wind with Mercury and its small, but dynamic magnetosphere.

  7. Histochemical demonstration of mercury in the olfactory system of salmon (Salmo salar L.) following treatments with dietary methylmercuric chloride and dissolved mercuric chloride

    DEFF Research Database (Denmark)

    Baatrup, E; Døving, K B

    1991-01-01

    The deposition of organic and inorganic mercury compounds was studied histochemically in the salmon (Salmo salar L.) olfactory system. One group of salmon was given fodder pellets containing methylmercuric chloride (CH3HgCl, 99 micrograms Hg/g) for 4 weeks. Other groups of fish were exposed...... to dissolved mercuric chloride (HgCl2, 270 micrograms Hg/liter) for 2, 6, and 12 hr, respectively. In both series of experiments, the radioisotope 203Hg was included in order to determine the accumulation of mercury in the olfactory system. Gamma-spectrometry showed that both mercury compounds accumulated...... in the axons and Schwann cells of both methylmercury- and inorganic mercury-exposed fish. On the other hand, the two mercury compounds showed different staining patterns in the sensory epithelium. The silver grains evoked by methylmercury were localized predominantly in lysosome-like inclusions within...

  8. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS (A Toroidal LHC Apparatus). The ALFA system is composed by four stations installed in the LHC tunnel 240 m away from the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronics for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  9. ALFA Detector Control System

    CERN Document Server

    Oleiro Seabra, Luis Filipe; The ATLAS collaboration

    2015-01-01

    ALFA (Absolute Luminosity For ATLAS) is one of the sub-detectors of ATLAS/LHC. The ALFA system is composed by two stations installed in the LHC tunnel 240 m away from each side of the ATLAS interaction point. Each station has a vacuum and ventilation system, movement control and all the required electronic for signal processing. The Detector Control System (DCS) provides control and monitoring of several components and ensures the safe operation of the detector contributing to good Data Quality. This paper describes the ALFA DCS system including a detector overview, operation aspects and hardware control through a SCADA system, WinCC OA.

  10. The MESSENGER mission to Mercury: scientific objectives and implementation

    Science.gov (United States)

    Solomon, Sean C.; McNutt, Ralph L.; Gold, Robert E.; Acuña, Mario H.; Baker, Daniel N.; Boynton, William V.; Chapman, Clark R.; Cheng, Andrew F.; Gloeckler, George; Head, James W., III; Krimigis, Stamatios M.; McClintock, William E.; Murchie, Scott L.; Peale, Stanton J.; Phillips, Roger J.; Robinson, Mark S.; Slavin, James A.; Smith, David E.; Strom, Robert G.; Trombka, Jacob I.; Zuber, Maria T.

    2001-12-01

    Mercury holds answers to several critical questions regarding the formation and evolution of the terrestrial planets. These questions include the origin of Mercury's anomalously high ratio of metal to silicate and its implications for planetary accretion processes, the nature of Mercury's geological evolution and interior cooling history, the mechanism of global magnetic field generation, the state of Mercury's core, and the processes controlling volatile species in Mercury's polar deposits, exosphere, and magnetosphere. The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission has been designed to fly by and orbit Mercury to address all of these key questions. After launch by a Delta 2925H-9.5, two flybys of Venus, and two flybys of Mercury, orbit insertion is accomplished at the third Mercury encounter. The instrument payload includes a dual imaging system for wide and narrow fields-of-view, monochrome and color imaging, and stereo; X-ray and combined gamma-ray and neutron spectrometers for surface chemical mapping; a magnetometer; a laser altimeter; a combined ultraviolet-visible and visible-near-infrared spectrometer to survey both exospheric species and surface mineralogy; and an energetic particle and plasma spectrometer to sample charged species in the magnetosphere. During the flybys of Mercury, regions unexplored by Mariner 10 will be seen for the first time, and new data will be gathered on Mercury's exosphere, magnetosphere, and surface composition. During the orbital phase of the mission, one Earth year in duration, MESSENGER will complete global mapping and the detailed characterization of the exosphere, magnetosphere, surface, and interior.

  11. Motion control systems

    CERN Document Server

    Sabanovic, Asif

    2011-01-01

    "Presents a unified approach to the fundamental issues in motion control, starting from the basics and moving through single degree of freedom and multi-degree of freedom systems In Motion Control Systems, Šabanovic and Ohnishi present a unified approach to very diverse issues covered in motion control systems, offering know-how accumulated through work on very diverse problems into a comprehensive, integrated approach suitable for application in high demanding high-tech products. It covers material from single degree of freedom systems to complex multi-body non-redundant and redundant systems. The discussion of the main subject is based on original research results and will give treatment of the issues in motion control in the framework of the acceleration control method with disturbance rejection technique. This allows consistent unification of different issues in motion control ranging from simple trajectory tracking to topics related to haptics and bilateral control without and with delay in the measure...

  12. A modular control system

    International Nuclear Information System (INIS)

    Cruz, B.; Drexler, J.; Olcese, G.; Santome, D.

    1990-01-01

    The main objective of the modular control system is to provide the requirements to most of the processes supervision and control applications within the industrial automatization area. The design is based on distribution, modulation and expansion concepts. (Author) [es

  13. Review of technologies for mercury removal from flue gas from cement production processes

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Anker Degn; Windelin, Christian

    2012-01-01

    Mercury is a pollutant of concern and mercury emissions from cement plants are under environmental regulation. After coal-fired power plants, mercury emissions from cement and mineral production are the second largest anthropogenic sources. Compared to fuels, cement raw materials are the major...... sources of mercury in the cement kiln flue gas. Cement plants are quite different from power plants and waste incinerators regarding the flue gas composition, temperature, residence time, and material circulation. Cement kiln systems have some inherent ability to retain mercury in the solid materials due...... kilns.Among the mercury control technologies, sorbent injection upstream of a particulate control device has shown the most promise. Due to material recirculation, and high moisture level in the cement kiln flue gas the application of sorbent injection to cement plants will be more challenging...

  14. Intelligent Control Systems Research

    Science.gov (United States)

    Loparo, Kenneth A.

    1994-01-01

    Results of a three phase research program into intelligent control systems are presented. The first phase looked at implementing the lowest or direct level of a hierarchical control scheme using a reinforcement learning approach assuming no a priori information about the system under control. The second phase involved the design of an adaptive/optimizing level of the hierarchy and its interaction with the direct control level. The third and final phase of the research was aimed at combining the results of the previous phases with some a priori information about the controlled system.

  15. Control and optimization system

    Science.gov (United States)

    Xinsheng, Lou

    2013-02-12

    A system for optimizing a power plant includes a chemical loop having an input for receiving an input parameter (270) and an output for outputting an output parameter (280), a control system operably connected to the chemical loop and having a multiple controller part (230) comprising a model-free controller. The control system receives the output parameter (280), optimizes the input parameter (270) based on the received output parameter (280), and outputs an optimized input parameter (270) to the input of the chemical loop to control a process of the chemical loop in an optimized manner.

  16. Control systems engineering

    CERN Document Server

    Nise, Norman S

    1995-01-01

    This completely updated new edition shows how to use MATLAB to perform control-system calculations. Designed for the professional or engineering student who needs a quick and readable update on designing control systems, the text features a series of tightly focused examples that clearly illustrate each concept of designing control systems. Most chapters conclude with a detailed application from the two case studies that run throughout the book: an antenna asimuth control system and a submarine. The author also refers to many examples of design methods.

  17. Fault Tolerant Control Systems

    DEFF Research Database (Denmark)

    Bøgh, S. A.

    This thesis considered the development of fault tolerant control systems. The focus was on the category of automated processes that do not necessarily comprise a high number of identical sensors and actuators to maintain safe operation, but still have a potential for improving immunity to component...... failures. It is often feasible to increase availability for these control loops by designing the control system to perform on-line detection and reconfiguration in case of faults before the safety system makes a close-down of the process. A general development methodology is given in the thesis...... that carried the control system designer through the steps necessary to consider fault handling in an early design phase. It was shown how an existing control loop with interface to the plant wide control system could be extended with three additional modules to obtain fault tolerance: Fault detection...

  18. Discrete control systems

    CERN Document Server

    Okuyama, Yoshifumi

    2014-01-01

    Discrete Control Systems establishes a basis for the analysis and design of discretized/quantized control systemsfor continuous physical systems. Beginning with the necessary mathematical foundations and system-model descriptions, the text moves on to derive a robust stability condition. To keep a practical perspective on the uncertain physical systems considered, most of the methods treated are carried out in the frequency domain. As part of the design procedure, modified Nyquist–Hall and Nichols diagrams are presented and discretized proportional–integral–derivative control schemes are reconsidered. Schemes for model-reference feedback and discrete-type observers are proposed. Although single-loop feedback systems form the core of the text, some consideration is given to multiple loops and nonlinearities. The robust control performance and stability of interval systems (with multiple uncertainties) are outlined. Finally, the monograph describes the relationship between feedback-control and discrete ev...

  19. Relation of Mercury to Other Chemical Constituents in Ground Water in the Kirkwood-Cohansey Aquifer System, New Jersey Coastal Plain, and Mechanisms for Mobilization of Mercury from Sediments to Ground Water

    Science.gov (United States)

    Barringer, Julia L.; MacLeod, Cecilia L.

    2001-01-01

    Water from 265 domestic wells that tap the unconfined Kirkwood-Cohansey aquifer system in the Coastal Plain of New Jersey contained concentrations of mercury that are equal to or exceed the U.S. Environmental Protection Agency maximum contaminant level (MCL) of 2 ug/L (micrograms per liter). The wells range in depth from 50 to 200 feet, and are located in 32 discrete, mostly residential, areas that were developed primarily on former agricultural land during the 1950?s through the 1970?s. Concentrations in two other areas exceeded 1 ug/L. Naturally occurring mercury concentrations in ground water from the Kirkwood-Cohansey aquifer system typically are less than 0.01 ug/L, but concentrations in water from some wells were as much as 42 ug/L. No evidence currently exists that conclusively links known point sources such as landfills, industrial operations, or commercial enterprises to most of the elevated concentrations of mercury in ground water in the residential areas. Possible sources of the mercury include pesticides and atmospheric deposition. Analysis of water from wells in 6 of the 34 areas for other constituents indicates that nitrate concentrations also commonly are elevated above background levels (which typically are undetectable at 0.01 milligrams per liter), and exceed the MCL of 10 milligrams per liter in some samples. Several volatile organic compounds (VOCs), including chloroform, also have been measured in water from wells at many of the 34 sites. Analytical results for water samples collected at several depths from boreholes at 2 of the 34 sites indicate elevated concentrations of calcium, magnesium, barium, strontium, nitrate, and chloride, which may be related to both agricultural chemical applications and septic-system effluent. Determinations of tritium and helium concentrations indicate that water containing elevated concentrations of mercury recharged the aquifer between 9.4 and 79 years ago, which includes the period during which many of the 34

  20. Mercury, phthalates, and ionizing radiations in neonatal intensive care controls. Adverse effects and preventive measures

    International Nuclear Information System (INIS)

    Zarlenga, Mercedes; Somaruga, Luis

    2006-01-01

    Studies realized by important institutions in the world have demonstrated that the load of illnesses associated with environmental and occupational conditions are affected by the current generation, especially to the most vulnerable populations as are the newborn babies. In the present work, the effects of the mercury, the phthalates and the ionizing radiations on the neonates health are described [es

  1. NOVEL ECONOMICAL HG(0) OXIDATION REAGENT FOR MERCURY EMISSIONS CONTROL FROM COAL-FIRED BOILERS

    Science.gov (United States)

    The authors have developed a novel economical additive for elemental mercury (Hg0) removal from coal-fired boilers. The oxidation reagent was rigorously tested in a lab-scale fixed-bed column with the Norit America's FGD activated carbon (DOE's benchmark sorbent) in a typical PRB...

  2. Mercury and plants in contaminated soils. 1: Uptake, partitioning, and emission to the atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, T.L.; Gustin, M.S.; Fernandez, G.C.J. [Univ. of Nevada, Reno, NV (United States); Taylor, G.E. Jr. [George Mason Univ., Fairfax, VA (United States). Dept. of Biology

    1998-10-01

    The uptake, distribution, and subsequent emission of mercury to the atmosphere were investigated in five plant species (Lepidium latifolium [L.], Artemisia douglasiana [Bess in Hook], Caulanthus sp. [S. Watson], Fragaria vesca [L.], and Eucalyptus globulus [Labill]) with different ecological and physiological attributes. Transfer coefficients for mercury in the soil-plant system were calculated. Plant-to-atmosphere emissions of mercury were determined using a controlled environment gas-exchange system and ranged from 10 to 93 mg/m{sup 2}/h in the light; emissions in the dark were an order of magnitude less. Transfer coefficients for mercury within the soil-plant system increased acropetally (root-to-leaf axis) by orders of magnitude. Estimated mercury emissions from plants in the Carson River Drainage Basin of Nevada over the growing season (0.5 mg/m{sup 2}) add to the previously reported soil mercury emissions (8.5 mg/m{sup 2}), resulting in total landscape emissions of 9 mg/m{sup 2}. For L. latifolium, 70% of the mercury taken up by the roots during the growing season was emitted to the atmosphere. For every one molecule of mercury retained in foliage of L. latifolium, 12 molecules of mercury were emitted. Within this arid ecosystem, mercury emissions are a dominant pathway of the mercury cycle. Plants function as conduits for the interfacial transport of mercury from the geosphere to the atmosphere, and this role is undervalued in models of the behavior of mercury in terrestrial exosystems and in the atmosphere on a global scale.

  3. Control system design guide

    Energy Technology Data Exchange (ETDEWEB)

    Sellers, David; Friedman, Hannah; Haasl, Tudi; Bourassa, Norman; Piette, Mary Ann

    2003-05-01

    The ''Control System Design Guide'' (Design Guide) provides methods and recommendations for the control system design process and control point selection and installation. Control systems are often the most problematic system in a building. A good design process that takes into account maintenance, operation, and commissioning can lead to a smoothly operating and efficient building. To this end, the Design Guide provides a toolbox of templates for improving control system design and specification. HVAC designers are the primary audience for the Design Guide. The control design process it presents will help produce well-designed control systems that achieve efficient and robust operation. The spreadsheet examples for control valve schedules, damper schedules, and points lists can streamline the use of the control system design concepts set forth in the Design Guide by providing convenient starting points from which designers can build. Although each reader brings their own unique questions to the text, the Design Guide contains information that designers, commissioning providers, operators, and owners will find useful.

  4. Control rod shutdown system

    International Nuclear Information System (INIS)

    Miyamoto, Yoshiyuki; Higashigawa, Yuichi.

    1996-01-01

    The present invention provides a control rod terminating system in a BWR type nuclear power plant, which stops an induction electric motor as rapidly as possible to terminate the control rods. Namely, the control rod stopping system controls reactor power by inserting/withdrawing control rods into a reactor by driving them by the induction electric motor. The system is provided with a control device for controlling the control rods and a control device for controlling the braking device. The control device outputs a braking operation signal for actuating the braking device during operation of the control rods to stop the operation of the control rods. Further, the braking device has at least two kinds of breaks, namely, a first and a second brakes. The two kinds of brakes are actuated by receiving the brake operation signals at different timings. The brake device is used also for keeping the control rods after the stopping. Even if a stopping torque of each of the breaks is small, different two kinds of brakes are operated at different timings thereby capable of obtaining a large stopping torque as a total. (I.S.)

  5. Systems and Control Engineering

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 5. Systems and Control Engineering - Control Systems-Analysis and Design. A Rama Kalyan J R Vengateswaran. General Article Volume 4 Issue 5 May 1999 pp 88-94 ...

  6. FGD Additives to Segregate and Sequester Mercury in Solid Byproducts - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Searcy, K; Bltyhe, G M; Steen, W A

    2012-02-28

    Many mercury control strategies for U.S. coal-fired power generating plants involve co-benefit capture of oxidized mercury from flue gases treated by wet flue gas desulfurization (FGD) systems. For these processes to be effective at overall mercury control, the captured mercury must not be re-emitted to the atmosphere or into surface or ground water. The project sought to identify scrubber additives and FGD operating conditions under which mercury re-emissions would decrease and mercury would remain in the liquor and be blown down from the system in the chloride purge stream. After exiting the FGD system, mercury would react with precipitating agents to form stable solid byproducts and would be removed in a dewatering step. The FGD gypsum solids, free of most of the mercury, could then be disposed or processed for reuse as wallboard or in other beneficial reuse. The project comprised extensive bench-scale FGD scrubber tests in Phases I and II. During Phase II, the approaches developed at the bench scale were tested at the pilot scale. Laboratory wastewater treatment tests measured the performance of precipitating agents in removing mercury from the chloride purge stream. Finally, the economic viability of the approaches tested was evaluated.

  7. Spacecraft momentum control systems

    CERN Document Server

    Leve, Frederick A; Peck, Mason A

    2015-01-01

    The goal of this book is to serve both as a practical technical reference and a resource for gaining a fuller understanding of the state of the art of spacecraft momentum control systems, specifically looking at control moment gyroscopes (CMGs). As a result, the subject matter includes theory, technology, and systems engineering. The authors combine material on system-level architecture of spacecraft that feature momentum-control systems with material about the momentum-control hardware and software. This also encompasses material on the theoretical and algorithmic approaches to the control of space vehicles with CMGs. In essence, CMGs are the attitude-control actuators that make contemporary highly agile spacecraft possible. The rise of commercial Earth imaging, the advances in privately built spacecraft (including small satellites), and the growing popularity of the subject matter in academic circles over the past decade argues that now is the time for an in-depth treatment of the topic. CMGs are augmented ...

  8. Systems and Control Engineering

    Indian Academy of Sciences (India)

    Systems and Control Engineering. 1. Notions of Control. A Rama Kalyan and J R Vengateswaran. To control an object means to influence its behaviour so as to achieve a desired goal. To implement this influence, engineers build various devices that incorporate several mathematical techniques. The study of these devices ...

  9. Neutron generator control system

    International Nuclear Information System (INIS)

    Peelman, H.E.; Bridges, J.R.

    1981-01-01

    A method is described of controlling the neutron output of a neutron generator tube used in neutron well logging. The system operates by monitoring the target beam current and comparing a function of this current with a reference voltage level to develop a control signal used in a series regulator to control the replenisher current of the neutron generator tube. (U.K.)

  10. Dynamic Systems and Control Engineering

    International Nuclear Information System (INIS)

    Kim, Jong Seok

    1994-02-01

    This book deals with introduction of dynamic system and control engineering, frequency domain modeling of dynamic system, temporal modeling of dynamic system, typical dynamic system and automatic control device, performance and stability of control system, root locus analysis, analysis of frequency domain dynamic system, design of frequency domain dynamic system, design and analysis of space, space of control system and digital control system such as control system design of direct digital and digitalization of consecutive control system.

  11. Analysis of Soil Parameters in Almadenejos. Behavior of Mercury in Soil-Plant System

    International Nuclear Information System (INIS)

    Fernandez, R.; Sierra, M. J.; Villadoniga, M.; Millan, R.

    2010-01-01

    This scientific-technical report is the result of the stay of Rocio Fernandez Flores practices in the Research Unit soil degradation of the Department of Environment CIEMAT. The aim of this study is to determine the behaviour of mercury in soil of Almadenejos (Almaden, Ciudad Real, Espana) by using a six-step sequential extraction procedure and evaluate the transfer of this pollutant to Marrubium vulgare L., predominant in the area and studied for years due to its ability to accumulate large amounts of mercury without visual symptoms of toxicity. Furthermore, the results will be useful in order to determine if this plant specie could be used as phyto extractor in the recovery mercury contaminated soils. The results show that total mercury concentrations in soil ranged from 709 mg kg-1 to 22,616 mg kg-1. Regarding mercury distribution among different soil fractions, this heavy metal is mainly found in the fraction assigned in the fi nal insoluble residues, the oxidizable fraction and in the crystalline Fe-Mn oxydroxides, on the other hand, barely 1% or lower is readily available to plants However, Marrubium vulgare is able to accumulate high amount of mercury (3.5 - 373.5 mg kg-1). Regarding the mercury distribution inside the plant, mercury concentration in the root was higher than in the aerial part. Within the aerial part the maximum mercury concentration was generally found in leaves. According to the obtained results, Marrubium vulgare L. could be considered as a (hyper)accumulator plant. (Author) 57 refs.

  12. The control system

    International Nuclear Information System (INIS)

    1988-01-01

    The present control system has matured both in terms of age and capacity. Thus a new system based on a local area network (LAN) is being developed. A pilot project has been started but, owing to difficulties encountered with the present operating system used with the microprocessors, it has become necessary to reconsider the choice of operating system. A recently-released multi-tasking operating system that runs on the existing hardware has been chosen. 1 fig

  13. Magnetic spectrometer control system

    International Nuclear Information System (INIS)

    Lecca, L.A.; Di Paolo, Hugo; Fernandez Niello, Jorge O.; Marti, Guillermo V; Pacheco, Alberto J.; Ramirez, Marcelo

    2003-01-01

    The design and implementation of a new computerized control system for the several devices of the magnetic spectrometer at TANDAR Laboratory is described. This system, as a main difference from the preexisting one, is compatible with almost any operating systems of wide spread use available in PC. This allows on-line measurement and control of all signals from any terminal of a computer network. (author)

  14. Drone Control System

    Science.gov (United States)

    1983-01-01

    Drones, subscale vehicles like the Firebees, and full scale retired military aircraft are used to test air defense missile systems. The DFCS (Drone Formation Control System) computer, developed by IBM (International Business Machines) Federal Systems Division, can track ten drones at once. A program called ORACLS is used to generate software to track and control Drones. It was originally developed by Langley and supplied by COSMIC (Computer Software Management and Information Center). The program saved the company both time and money.

  15. PRESSURE SYSTEM CONTROL

    Science.gov (United States)

    Esselman, W.H.; Kaplan, G.M.

    1961-06-20

    The control of pressure in pressurized liquid systems, especially a pressurized liquid reactor system, may be achieved by providing a bias circuit or loop across a closed loop having a flow restriction means in the form of an orifice, a storage tank, and a pump connected in series. The subject invention is advantageously utilized where control of a reactor can be achieved by response to the temperature and pressure of the primary cooling system.

  16. Mercury reduction and removal during high-level radioactive waste processing and vitrification

    International Nuclear Information System (INIS)

    Eibling, R.E.; Fowler, J.R.

    1981-01-01

    A reference process for immobilizing the high-level radioactive waste in borosilicate glass has been developed at the Savannah River Plant. This waste contains a substantial amount of mercury from separations processing. Because mercury will not remain in borosilicate glass at the processing temperature, mercury must be removed before vitrification or must be handled in the off-gas system. A process has been developed to remove mercury by reduction with formic acid prior to vitrification. Additional benefits of formic acid treatment include improved sludge handling and glass melter redox control

  17. A regional high resolution model of the marine mercury cycle.

    Science.gov (United States)

    Bieser, J.; Daewel, U.; Schrum, C.

    2017-12-01

    One of the main sources for mercury intoxication is the uptake of methylmercury from sea food. However, only little is known about the dynamics of methylmercury in the marine environment and its accumulation along the food chain. To further our understanding of the pathways from anthropogenic emissions of elemental mercury to the bio-accumulation of methylmercury in fish we developed the first regional Eulerian three dimensional multi-media chemistry transport model (MECOSMO) that includes atmosphere, ocean, and ecosystem. The marine part of the model includes a complete representation of the marine ecosystem ranging from phytoplankton up to higher trophic levels, including fish. We used the MECOSMO model to reconstruct mercury concentrations in water and biota in the North- and Baltic Sea for the past 60 years. Based on our model we examined the natural short and longterm variability of the system as well as long term trends in the distribution and amount of methylmercury in water and fish. Based on our findings we show how models can be utilized to develop future measurement strategies for marine mercury. Finally, the presented modelling system can be used to project the impact of future perturbations in the system (i.e.: emission reductions, climate change, nutrient control) on the mercury accumulation in sea food. Thereby, supporting the implementation of the Minamata Convention on Mercury on a regional scale by enabling us to estimate the impact of emission reductions on the marine mercury cycle.

  18. System control and communication

    International Nuclear Information System (INIS)

    Bindner, H.; Oestergaard, J.

    2005-01-01

    Rapid and ongoing development in the energy sector has consequences for system control at all levels. In relation to system control and communication the control system is challenged in five important ways: 1) Expectations for security of supply, robustness and vulnerability are becoming more stringent, and the control system plays a big part in meeting these expectations. 2) Services are becoming increasingly based on markets that involve the transmission system operators (TSOs), generators and distribution companies. Timely, accurate and secure communication is essential to the smooth running of the markets. 3) Adding large amounts of renewable energy (RE) to the mix is a challenge for control systems because of the intermittent availability of many RE sources. 4) Increasing the number of active components in the system, such as small CHP plants, micro-CHP and intelligent loads, means that the system control will be much more complex. 5) In the future it is likely that power, heat, gas, transport and communication systems will be tighter coupled and interact much more. (au)

  19. Mercury's Dynamic Magnetic Tail

    Science.gov (United States)

    Slavin, James A.

    2010-01-01

    The Mariner 10 and MESSENGER flybys of Mercury have revealed a magnetosphere that is likely the most responsive to upstream interplanetary conditions of any in the solar system. The source of the great dynamic variability observed during these brief passages is due to Mercury's proximity to the Sun and the inverse proportionality between reconnection rate and solar wind Alfven Mach number. However, this planet's lack of an ionosphere and its small physical dimensions also contribute to Mercury's very brief Dungey cycle, approx. 2 min, which governs the time scale for internal plasma circulation. Current observations and understanding of the structure and dynamics of Mercury's magnetotail are summarized and discussed. Special emphasis will be placed upon such questions as: 1) How much access does the solar wind have to this small magnetosphere as a function of upstream conditions? 2) What roles do heavy planetary ions play? 3) Do Earth-like substorms take place at Mercury? 4) How does Mercury's tail respond to extreme solar wind events such coronal mass ejections? Prospects for progress due to advances in the global magnetohydrodynamic and hybrid simulation modeling and the measurements to be taken by MESSENGER after it enters Mercury orbit on March 18, 2011 will be discussed.

  20. The CEBAF control system

    International Nuclear Information System (INIS)

    Watson, W.A. III.

    1995-01-01

    CEBAF has recently upgraded its accelerator control system to use EPICS, a control system toolkit being developed by a collaboration among laboratories in the US and Europe. The migration to EPICS has taken place during a year of intense commissioning activity, with new and old control systems operating concurrently. Existing CAMAC hardware was preserved by adding a CAMAC serial highway link to VME; newer hardware developments are now primarily in VME. Software is distributed among three tiers of computers: first, workstations and X terminals for operator interfaces and high level applications; second, VME single board computers for distributed access to hardware and for local control processing; third, embedded processors where needed for faster closed loop operation. This system has demonstrated the ability to scale EPICS to controlling thousands of devices, including hundreds of embedded processors, with control distributed among dozens of VME processors executing more than 125,000 EPICS database records. To deal with the large size of the control system, CEBAF has integrated an object oriented database, providing data management capabilities for both low level I/O and high level machine modeling. A new callable interface which is control system independent permits access to live EPICS data, data in other Unix processes, and data contained in the object oriented database

  1. Real-time analysis of total, elemental, and total speciated mercury

    International Nuclear Information System (INIS)

    Schlager, R.J.; Wilson, K.G.; Sappey, A.D.

    1995-01-01

    ADA Technologies, Inc., is developing a continuous emissions monitoring system that measures the concentrations of mercury in flue gas. Mercury is emitted as an air pollutant from a number of industrial processes. The largest contributors of these emissions are coal and oil combustion, municipal waste combustion, medical waste combustion, and the thermal treatment of hazardous materials. It is difficult, time consuming, and expensive to measure mercury emissions using current testing methods. Part of the difficulty lies in the fact that mercury is emitted from sources in several different forms, such as elemental mercury and mercuric chloride. The ADA analyzer measures these emissions in real time, thus providing a number of advantages over existing test methods: (1) it will provide a real-time measure of emission rates, (2) it will assure facility operators, regulators, and the public that emissions control systems are working at peak efficiency, and (3) it will provide information as to the nature of the emitted mercury (elemental mercury or speciated compounds). This update presents an overview of the CEM and describes features of key components of the monitoring system--the mercury detector, a mercury species converter, and the analyzer calibration system

  2. Real-time analysis of total, elemental, and total speciated mercury

    Energy Technology Data Exchange (ETDEWEB)

    Schlager, R.J.; Wilson, K.G.; Sappey, A.D. [ADA Technologies, Inc., Englewood, CO (United States)

    1995-11-01

    ADA Technologies, Inc., is developing a continuous emissions monitoring system that measures the concentrations of mercury in flue gas. Mercury is emitted as an air pollutant from a number of industrial processes. The largest contributors of these emissions are coal and oil combustion, municipal waste combustion, medical waste combustion, and the thermal treatment of hazardous materials. It is difficult, time consuming, and expensive to measure mercury emissions using current testing methods. Part of the difficulty lies in the fact that mercury is emitted from sources in several different forms, such as elemental mercury and mercuric chloride. The ADA analyzer measures these emissions in real time, thus providing a number of advantages over existing test methods: (1) it will provide a real-time measure of emission rates, (2) it will assure facility operators, regulators, and the public that emissions control systems are working at peak efficiency, and (3) it will provide information as to the nature of the emitted mercury (elemental mercury or speciated compounds). This update presents an overview of the CEM and describes features of key components of the monitoring system--the mercury detector, a mercury species converter, and the analyzer calibration system.

  3. Load Control System Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Trudnowski, Daniel [Montana Tech of the Univ. of Montana, Butte, MT (United States)

    2015-04-03

    This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”

  4. Basic Information about Mercury

    Science.gov (United States)

    ... Your Environment Contact Us Share Basic Information about Mercury On this page: What is mercury? Emissions of ... Consumer products that traditionally contain mercury What is Mercury? Mercury is a naturally-occurring chemical element found ...

  5. ISTTOK control system upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ivo S., E-mail: ivoc@ipfn.ist.utl.pt; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Carvalho, Bernardo B.

    2013-10-15

    Highlights: •ISTTOK fast controller. •All real-time diagnostic and actuators were integrated in the control platform. •100 μs control cycle under the MARTe framework. •The ISTTOK control system upgrade provides reliable operation with an improved operational space. -- Abstract: The ISTTOK tokamak (Ip = 4 kA, BT = 0.5 T, R = 0.46 m, a = 0.085 m) is one of the few tokamaks with regular alternate plasma current (AC) discharges scientific programme. In order to improve the discharge stability and to increase the number of AC discharge cycles a novel control system was developed. The controller acquires data from 50 analog-to-digital converter (ADC) channels of real-time diagnostics and measurements: tomography, Mirnov coils, interferometer, electric probes, sine and cosine probes, bolometer, current delivered by the power supplies, loop voltage and plasma current. The system has a control cycle of 100 μs during which it reads all the diagnostics connected to the advanced telecommunications computing architecture (ATCA) digitizers and sends the control reference to ISTTOK actuators. The controller algorithms are executed on an Intel{sup ®} Q8200 chip with 4 cores running at 2.33 GHz and connected to the I/O interfaces through an ATCA based environment. The real-time control system was programmed in C++ on top of the Multi-threaded Application Real-Time executor (MARTe). To extend the duration of the AC discharges and the plasma stability a new magnetising field power supply was commissioned and the horizontal and vertical field power supplies were also upgraded. The new system also features a user-friendly interface based on HyperText Markup Language (HTML) and Javascript to configure the controller parameters. This paper presents the ISTTOK control system and the consequent update of real-time diagnostics and actuators.

  6. Method development for the control determination of mercury in seafood by solid-sampling thermal decomposition amalgamation atomic absorption spectrometry (TDA AAS).

    Science.gov (United States)

    Torres, D P; Martins-Teixeira, M B; Silva, E F; Queiroz, H M

    2012-01-01

    A very simple and rapid method for the determination of total mercury in fish samples using the Direct Mercury Analyser DMA-80 was developed. In this system, a previously weighted portion of fresh fish is combusted and the released mercury is selectively trapped in a gold amalgamator. Upon heating, mercury is desorbed from the amalgamator, an atomic absorption measurement is performed and the mercury concentration is calculated. Some experimental parameters have been studied and optimised. In this study the sample mass was about 100.0 mg. The relative standard deviation was lower than 8.0% for all measurements of solid samples. Two calibration curves against aqueous standard solutions were prepared through the low linear range from 2.5 to 20.0 ng of Hg, and the high linear range from 25.0 to 200.0 ng of Hg, for which a correlation coefficient better than 0.997 was achieved, as well as a normal distribution of the residuals. Mercury reference solutions were prepared in 5.0% v/v nitric acid medium. Lyophilised fish tissues were also analysed; however, the additional procedure had no advantage over the direct analysis of the fresh fish, and additionally increased the total analytical process time. A fish tissue reference material, IAEA-407, was analysed and the mercury concentration was in agreement with the certified value, according to the t-test at a 95% confidence level. The limit of quantification (LOQ), based on a mercury-free sample, was 3.0 µg kg(-1). This LOQ is in accordance with performance criteria required by the Commission Regulation No. 333/2007. Simplicity and high efficiency, without the need for any sample preparation procedure, are some of the qualities of the proposed method.

  7. Control system integration

    CERN Document Server

    Shea, T J

    2008-01-01

    This lecture begins with a definition of an accelerator control system, and then reviews the control system architectures that have been deployed at the larger accelerator facilities. This discussion naturally leads to identification of the major subsystems and their interfaces. We shall explore general strategies for integrating intelligent devices and signal processing subsystems based on gate arrays and programmable DSPs. The following topics will also be covered: physical packaging; timing and synchronization; local and global communication technologies; interfacing to machine protection systems; remote debugging; configuration management and source code control; and integration of commercial software tools. Several practical realizations will be presented.

  8. Recent Approaches to Modeling Transport of Mercury in Surface Water and Groundwater - Case Study in Upper East Fork Poplar Creek, Oak Ridge, TN - 13349

    International Nuclear Information System (INIS)

    Bostick, Kent; Daniel, Anamary; Tachiev, Georgio; Malek-Mohammadi, Siamak

    2013-01-01

    In this case study, groundwater/surface water modeling was used to determine efficacy of stabilization in place with hydrologic isolation for remediation of mercury contaminated areas in the Upper East Fork Poplar Creek (UEFPC) Watershed in Oak Ridge, TN. The modeling simulates the potential for mercury in soil to contaminate groundwater above industrial use risk standards and to contribute to surface water contamination. The modeling approach is unique in that it couples watershed hydrology with the total mercury transport and provides a tool for analysis of changes in mercury load related to daily precipitation, evaporation, and runoff from storms. The model also allows for simulation of colloidal transport of total mercury in surface water. Previous models for the watershed only simulated average yearly conditions and dissolved concentrations that are not sufficient for predicting mercury flux under variable flow conditions that control colloidal transport of mercury in the watershed. The transport of mercury from groundwater to surface water from mercury sources identified from information in the Oak Ridge Environmental Information System was simulated using a watershed scale model calibrated to match observed daily creek flow, total suspended solids and mercury fluxes. Mercury sources at the former Building 81-10 area, where mercury was previously retorted, were modeled using a telescopic refined mesh with boundary conditions extracted from the watershed model. Modeling on a watershed scale indicated that only source excavation for soils/sediment in the vicinity of UEFPC had any effect on mercury flux in surface water. The simulations showed that colloidal transport contributed 85 percent of the total mercury flux leaving the UEFPC watershed under high flow conditions. Simulation of dissolved mercury transport from liquid elemental mercury and adsorbed sources in soil at former Building 81-10 indicated that dissolved concentrations are orders of magnitude

  9. Mercury transformation and speciation in flue gases from anthropogenic emission sources: a critical review

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2016-02-01

    Full Text Available Mercury transformation mechanisms and speciation profiles are reviewed for mercury formed in and released from flue gases of coal-fired boilers, non-ferrous metal smelters, cement plants, iron and steel plants, waste incinerators, biomass burning and so on. Mercury in coal, ores, and other raw materials is released to flue gases in the form of Hg0 during combustion or smelting in boilers, kilns or furnaces. Decreasing temperature from over 800 °C to below 300 °C in flue gases leaving boilers, kilns or furnaces promotes homogeneous and heterogeneous oxidation of Hg0 to gaseous divalent mercury (Hg2+, with a portion of Hg2+ adsorbed onto fly ash to form particulate-bound mercury (Hgp. Halogen is the primary oxidizer for Hg0 in flue gases, and active components (e.g., TiO2, Fe2O3, etc. on fly ash promote heterogeneous oxidation and adsorption processes. In addition to mercury removal, mercury transformation also occurs when passing through air pollution control devices (APCDs, affecting the mercury speciation in flue gases. In coal-fired power plants, selective catalytic reduction (SCR system promotes mercury oxidation by 34–85 %, electrostatic precipitator (ESP and fabric filter (FF remove over 99 % of Hgp, and wet flue gas desulfurization system (WFGD captures 60–95 % of Hg2+. In non-ferrous metal smelters, most Hg0 is converted to Hg2+ and removed in acid plants (APs. For cement clinker production, mercury cycling and operational conditions promote heterogeneous mercury oxidation and adsorption. The mercury speciation profiles in flue gases emitted to the atmosphere are determined by transformation mechanisms and mercury removal efficiencies by various APCDs. For all the sectors reviewed in this study, Hgp accounts for less than 5 % in flue gases. In China, mercury emission has a higher Hg0 fraction (66–82 % of total mercury in flue gases from coal combustion, in contrast to a greater Hg2+ fraction (29–90 % from non-ferrous metal

  10. Contribution to understanding and controlling a-Si:H thin films growth by mercury-sensitised photo-CVD

    International Nuclear Information System (INIS)

    Barhdadi, A.

    2003-09-01

    Mercury-sensitized photo-CVD technique is widely used for growing amorphous silicon thin films. This attractive method allows damage-free thin film depositions at very low substrate temperatures without the deleterious effects of the other processes. This review reports on the principle and potential of this technique. It also recalls and summarizes some fundamental issues such as experimental systems or apparatus particularities, the analysis of gas-phase reactions in the reactor, the surface-reaction model of SiH 3 and H during the film growth and all the kinetic model for lamp-induced Photo-CVD. (author)

  11. Five Hundred Years of Mercury Exposure and Adaptation

    Energy Technology Data Exchange (ETDEWEB)

    Lombardi, Guido [Laboratorio de Paleopatología, Cátedra Pedro Weiss, Universidad Peruana Cayetano Heredia, Lima, Peru; Lanzirotti, Antonio [CARS, The University of Chicago, Bulding 434A, 9700 South Cass Avenue, Argonne, IL 60439, USA; Qualls, Clifford [Departments of Mathematics and Statistics, The University of New Mexico, Albuquerque, NM 87131, USA; Socola, Francisco [Department of Medicine, Jackson Memorial Hospital, University of Miami, Miami, FL 33124, USA; Ali, Abdul-Mehdi [Department of Earth and Planetary Sciences, Analytical Chemistry Laboratory, University of New Mexico, Albuquerque, NM 87131, USA; Appenzeller, Otto [Department of Neurology, New Mexico Health Enhancement and Marathon Clinics Research Foundation, Albuquerque, NM 87122, USA

    2012-01-01

    Mercury is added to the biosphere by anthropogenic activities raising the question of whether changes in the human chromatin, induced by mercury, in a parental generation could allow adaptation of their descendants to mercury. We review the history of Andean mining since pre-Hispanic times in Huancavelica, Peru. Despite the persistent degradation of the biosphere today, no overt signs of mercury toxicity could be discerned in present day inhabitants. However, mercury is especially toxic to the autonomic nervous system (ANS). We, therefore, tested ANS function and biologic rhythms, under the control of the ANS, in 5 Huancavelicans and examined the metal content in their hair. Mercury levels varied from none to 1.014 ppm, significantly less than accepted standards. This was confirmed by microfocused synchrotron X-ray fluorescence analysis. Biologic rhythms were abnormal and hair growth rate per year, also under ANS control, was reduced (P<0.001). Thus, evidence of mercury’s toxicity in ANS function was found without other signs of intoxication. Our findings are consistent with the hypothesis of partial transgenerational inheritance of tolerance to mercury in Huancavelica, Peru. This would generally benefit survival in the Anthropocene, the man-made world, we now live in.

  12. Five Hundred Years of Mercury Exposure and Adaptation

    Directory of Open Access Journals (Sweden)

    Guido Lombardi

    2012-01-01

    Full Text Available Mercury is added to the biosphere by anthropogenic activities raising the question of whether changes in the human chromatin, induced by mercury, in a parental generation could allow adaptation of their descendants to mercury. We review the history of Andean mining since pre-Hispanic times in Huancavelica, Peru. Despite the persistent degradation of the biosphere today, no overt signs of mercury toxicity could be discerned in present day inhabitants. However, mercury is especially toxic to the autonomic nervous system (ANS. We, therefore, tested ANS function and biologic rhythms, under the control of the ANS, in 5 Huancavelicans and examined the metal content in their hair. Mercury levels varied from none to 1.014 ppm, significantly less than accepted standards. This was confirmed by microfocused synchrotron X-ray fluorescence analysis. Biologic rhythms were abnormal and hair growth rate per year, also under ANS control, was reduced (P<0.001. Thus, evidence of mercury’s toxicity in ANS function was found without other signs of intoxication. Our findings are consistent with the hypothesis of partial transgenerational inheritance of tolerance to mercury in Huancavelica, Peru. This would generally benefit survival in the Anthropocene, the man-made world, we now live in.

  13. A Review of Mercury Exposure and Health of Dental Personnel

    Directory of Open Access Journals (Sweden)

    Natasha Nagpal

    2017-03-01

    Full Text Available Considerable effort has been made to address the issue of occupational health and environmental exposure to mercury. This review reports on the current literature of mercury exposure and health impacts on dental personnel. Citations were searched using four comprehensive electronic databases for articles published between 2002 and 2015. All original articles that evaluated an association between the use of dental amalgam and occupational mercury exposure in dental personnel were included. Fifteen publications from nine different countries met the selection criteria. The design and quality of the studies showed significant variation, particularly in the choice of biomarkers as an indicator of mercury exposure. In several countries, dental personnel had higher mercury levels in biological fluids and tissues than in control groups; some work practices increased mercury exposure but the exposure levels remained below recommended guidelines. Dental personnel reported more health conditions, often involving the central nervous system, than the control groups. Clinical symptoms reported by dental professionals may be associated with low-level, long-term exposure to occupational mercury, but may also be due to the effects of aging, occupational overuse, and stress. It is important that dental personnel, researchers, and educators continue to encourage and monitor good work practices by dental professionals.

  14. CALCULATIONS FOR A MERCURY JET TARGET IN A SOLENOID MAGNET CAPTURE SYSTEM

    International Nuclear Information System (INIS)

    GALLARDO, J.; KAHN, S.; PALMER, R.B.; THIEBERGER, P.; WEGGEL, R.J.; MCDONALD, K.

    2001-01-01

    A mercury jet is being considered as the production target for a muon storage ring facility to produce an intense neutrino beam. A 20 T solenoid magnet that captures pions for muon production surrounds the mercury target. As the liquid metal jet enters or exits the field eddy currents are induced. We calculate the effects that a liquid metal jet experiences in entering and exiting the magnetic field for the magnetic configuration considered in the Neutrino Factory Feasibility Study II

  15. The Epicure Control System

    International Nuclear Information System (INIS)

    Dambik, E.; Kline, D.; West, R.

    1993-09-01

    The Epicure Control System supports the Fermilab fixed target physics program. The system is distributed across a network of many different types of components. The use of multiple layers on interfaces for communication between logical tasks fits the client-server model. Physical devices are read and controlled using symbolic references entered into a database with an editor utility. The database system consists of a central portion containing all device information and optimized portions distributed among many nodes. Updates to the database are available throughout the system within minutes after being requested

  16. Mercury exposure and risk of cardiovascular disease: a nested case-control study in the PREDIMED (PREvention with MEDiterranean Diet) study.

    Science.gov (United States)

    Downer, Mary K; Martínez-González, Miguel A; Gea, Alfredo; Stampfer, Meir; Warnberg, Julia; Ruiz-Canela, Miguel; Salas-Salvadó, Jordi; Corella, Dolores; Ros, Emilio; Fitó, Montse; Estruch, Ramon; Arós, Fernando; Fiol, Miquel; Lapetra, José; Serra-Majem, Lluís; Bullo, Monica; Sorli, Jose V; Muñoz, Miguel A; García-Rodriguez, Antonio; Gutierrez-Bedmar, Mario; Gómez-Gracia, Enrique

    2017-01-05

    Substantial evidence suggests that consuming 1-2 servings of fish per week, particularly oily fish (e.g., salmon, herring, sardines) is beneficial for cardiovascular health due to its high n-3 polyunsaturated fatty acid content. However, there is some concern that the mercury content in fish may increase cardiovascular disease risk, but this relationship remains unclear. The PREDIMED trial included 7477 participants who were at high risk for cardiovascular disease at baseline. In this study, we evaluated associations between mercury exposure, fish consumption and cardiovascular disease. We randomly selected 147 of the 288 cases diagnosed with cardiovascular disease during follow-up and matched them on age and sex to 267 controls. Instrumental neutron activation analysis was used to assess toenail mercury concentration. In-person interviews, medical record reviews and validated questionnaires were used to assess fish consumption and other covariates. Information was collected at baseline and updated yearly during follow-up. We used conditional logistic regression to evaluate associations in the total nested case-control study, and unconditional logistic regression for population subsets. Mean (±SD) toenail mercury concentrations (μg per gram) did not significantly differ between cases (0.63 (±0.53)) and controls (0.67 (±0.49)). Mercury concentration was not associated with cardiovascular disease in any analysis, and neither was fish consumption or n-3 fatty acids. The fully-adjusted relative risks for the highest versus lowest quartile of mercury concentration were 0.71 (95% Confidence Interval [CI], 0.34, 1.14; p trend  = 0.37) for the nested case-control study, 0.74 (95% CI, 0.32, 1.76; p trend  = 0.43) within the Mediterranean diet intervention group, and 0.50 (95% CI, 0.13, 1.96; p trend  = 0.41) within the control arm of the trial. Associations remained null when mercury was jointly assessed with fish consumption at baseline and during follow

  17. Control systems under attack?

    CERN Document Server

    Lüders, Stefan

    2005-01-01

    The enormous growth of the Internet during the last decade offers new means to share and distribute both information and data. In Industry, this results in a rapprochement of the production facilities, i.e. their Process Control and Automation Systems, and the data warehouses. At CERN, the Internet opens the possibility to monitor and even control (parts of) the LHC and its four experiments remotely from anywhere in the world. However, the adoption of standard IT technologies to Distributed Process Control and Automation Systems exposes inherent vulnerabilities to the world. The Teststand On Control System Security at CERN (TOCSSiC) is dedicated to explore the vulnerabilities of arbitrary Commercial-Of-The-Shelf hardware devices connected to standard Ethernet. As such, TOCSSiC should discover their vulnerabilities, point out areas of lack of security, and address areas of improvement which can then be confidentially communicated to manufacturers. This paper points out risks of accessing the Control and Automa...

  18. Control and Information Systems

    OpenAIRE

    Jiri Zahradnik; Karol Rastocny; Juraj Spalek

    2003-01-01

    The article deals with main tends of scientific research activities of Department of Control and Information Systems at the Faculty of Electrical Engineering of University of Zilina and its perspectives in this area.

  19. Control and Information Systems

    Directory of Open Access Journals (Sweden)

    Jiri Zahradnik

    2003-01-01

    Full Text Available The article deals with main tends of scientific research activities of Department of Control and Information Systems at the Faculty of Electrical Engineering of University of Zilina and its perspectives in this area.

  20. Locomotor behavioral response of mosquitofish (Gambusia affinis) to subacute mercury stress monitored by video tracking system.

    Science.gov (United States)

    Jakka, N M; Rao, T Gnaneshwar; Rao, J Venkateswara

    2007-01-01

    Locomotor behavior is commonly affected by contaminants, and the pattern of fish swimming is a highly organized species-specific response. In the current study, we examined the locomotor behavioral response of the mosquitofish, Gambusia affinis, which was exposed to a sublethal concentration (LC(5), 20 microg/L) of mercuric chloride (HgCl2) for 28 days and monitored using a computer vision system. The EthoVision video tracking system for automation of behavioral studies at regular intervals revealed abnormal locomotor behavior such as reduction in swimming speed (cm/s) and distance traveled per unit time. The effects of this metal on the gill morphology and bioaccumulation in different body parts were also investigated. High-resolution microscopy studies revealed abnormal gill morphology, with fusion of primary lamellae along with deep lesions and erosions in the secondary lamellae. The bioaccumulation concentrations in head, body, and viscera were determined by cold vapor atomic absorption spectrometric technique at regular intervals. The results indicated that the accumulation of mercury was the highest in viscera followed by head and body, with bioconcentration factors (BCFs) of 3.99, 2.18, and 1.57 and uptake rate constants (k1) of 17.91, 11.02, and 8.13, respectively. These observations indicate that alterations in fish behavior under subacute stress can provide important information useful in predicting the stress.

  1. Tautological control systems

    CERN Document Server

    Lewis, Andrew D

    2014-01-01

    This brief presents a description of a new modelling framework for nonlinear/geometric control theory. The framework is intended to be—and shown to be—feedback-invariant. As such, Tautological Control Systems provides a platform for understanding fundamental structural problems in geometric control theory. Part of the novelty of the text stems from the variety of regularity classes, e.g., Lipschitz, finitely differentiable, smooth, real analytic, with which it deals in a comprehensive and unified manner. The treatment of the important real analytic class especially reflects recent work on real analytic topologies by the author. Applied mathematicians interested in nonlinear and geometric control theory will find this brief of interest as a starting point for work in which feedback invariance is important. Graduate students working in control theory may also find Tautological Control Systems to be a stimulating starting point for their research.

  2. Reset Control Systems

    CERN Document Server

    Baños, Alfonso

    2012-01-01

    Reset Control Systems addresses the analysis for reset control treating both its basic form which requires only that the state of the controller be reinitialized to zero (the reset action) each time the tracking error crosses zero (the reset condition), and some useful variations of the reset action (partial reset with fixed or variable reset percentage) and of the reset condition (fixed or variable reset band and anticipative reset). The issues regarding reset control – concepts and motivation; analysis tools; and the application of design methodologies to real-world examples – are given comprehensive coverage. The text opens with an historical perspective which moves from the seminal work of the Clegg integrator and Horowitz FORE to more recent approaches based on impulsive/hybrid control systems and explains the motivation for reset compensation. Preliminary material dealing with notation, basic definitions and results, and with the definition of the control problem under study is also included. The fo...

  3. A new vapor generation system for mercury species based on the UV irradiation of mercaptoethanol used in the determination of total and methyl mercury in environmental and biological samples by atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Yanmin; Qiu, Jianhua; Yang, Limin [College of Chemistry and Chemical Engineering, Xiamen University, Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, Xiamen (China); Wang, Qiuquan [College of Chemistry and Chemical Engineering, Xiamen University, Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, Xiamen (China); Xiamen University, State Key Laboratory of Marine Environmental Science, Xiamen (China)

    2007-06-15

    A new vapor generation system for mercury (Hg) species based on the irradiation of mercaptoethanol (ME) with UV was developed to provide an effective sample introduction unit for atomic fluorescence spectrometry (AFS). Preliminary investigations of the mechanism of this novel vapor generation system were based on GC-MS and FT-IR studies. Under optimum conditions, the limits of determination for inorganic divalence mercury and methyl mercury were 60 and 50 pg mL{sup -1}, respectively. Certified reference materials (BCR 463 tuna fish and BCR 580 estuarine sediment) were used to validate this new method, and the results agreed well with certified values. This new system provides an attractive alternative method of chemical vapor generation (CVG) of mercury species compared to other developed CVG systems (for example, the traditional KBH{sub 4}/NaOH-acid system). To our knowledge, this is the first systematic report on UV/ME-based Hg species vapor generation and the determination of total and methyl Hg in environmental and biological samples using UV/ME-AFS. (orig.)

  4. Lighting Control System (ILCS)

    African Journals Online (AJOL)

    2017-08-08

    Aug 8, 2017 ... ABSTRACT. An Intelligent Lighting Control System (I ergonomic setting and energy efficiency. T and National Instrument Laboratory V. LabVIEW) 2012 as a platform to design an as integrating components within the sy controller programmed in NI LabVIEW pr of the light-emitting diode (LED conducted ...

  5. Controlling Uncertain Dynamical Systems

    Indian Academy of Sciences (India)

    ... Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 9. Controlling Uncertain Dynamical Systems - Basic Ideas of Adaptive Control. N Ananthkrishnan Rashi Bansal.

  6. Systems and Control Engineering

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 1. Systems and Control Engineering - Notions of Control. A Rama Kalyan J R Vengateswaran. General Article Volume 4 Issue 1 January 1999 pp 45-52. Fulltext. Click here to view fulltext PDF. Permanent link:

  7. Mercury Phase II Study - Mercury Behavior in Salt Processing Flowsheet

    Energy Technology Data Exchange (ETDEWEB)

    Jain, V. [Savannah River Remediation, LLC., Aiken, SC (United States); Shah, H. [Savannah River Remediation, LLC., Aiken, SC (United States). Sludge and Salt Planning; Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Wilmarth, W. R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-25

    Mercury (Hg) in the Savannah River Site Liquid Waste System (LWS) originated from decades of canyon processing where it was used as a catalyst for dissolving the aluminum cladding of reactor fuel. Approximately 60 metric tons of mercury is currently present throughout the LWS. Mercury has long been a consideration in the LWS, from both hazard and processing perspectives. In February 2015, a Mercury Program Team was established at the request of the Department of Energy to develop a comprehensive action plan for long-term management and removal of mercury. Evaluation was focused in two Phases. Phase I activities assessed the Liquid Waste inventory and chemical processing behavior using a system-by-system review methodology, and determined the speciation of the different mercury forms (Hg+, Hg++, elemental Hg, organomercury, and soluble versus insoluble mercury) within the LWS. Phase II activities are building on the Phase I activities, and results of the LWS flowsheet evaluations will be summarized in three reports: Mercury Behavior in the Salt Processing Flowsheet (i.e. this report); Mercury Behavior in the Defense Waste Processing Facility (DWPF) Flowsheet; and Mercury behavior in the Tank Farm Flowsheet (Evaporator Operations). The evaluation of the mercury behavior in the salt processing flowsheet indicates, inter alia, the following: (1) In the assembled Salt Batches 7, 8 and 9 in Tank 21, the total mercury is mostly soluble with methylmercury (MHg) contributing over 50% of the total mercury. Based on the analyses of samples from 2H Evaporator feed and drop tanks (Tanks 38/43), the source of MHg in Salt Batches 7, 8 and 9 can be attributed to the 2H evaporator concentrate used in assembling the salt batches. The 2H Evaporator is used to evaporate DWPF recycle water. (2) Comparison of data between Tank 21/49, Salt Solution Feed Tank (SSFT), Decontaminated Salt Solution Hold Tank (DSSHT), and Tank 50 samples suggests that the total mercury as well as speciated

  8. Mercury Phase II Study - Mercury Behavior in Salt Processing Flowsheet

    International Nuclear Information System (INIS)

    Jain, V.; Shah, H.; Wilmarth, W. R.

    2016-01-01

    Mercury (Hg) in the Savannah River Site Liquid Waste System (LWS) originated from decades of canyon processing where it was used as a catalyst for dissolving the aluminum cladding of reactor fuel. Approximately 60 metric tons of mercury is currently present throughout the LWS. Mercury has long been a consideration in the LWS, from both hazard and processing perspectives. In February 2015, a Mercury Program Team was established at the request of the Department of Energy to develop a comprehensive action plan for long-term management and removal of mercury. Evaluation was focused in two Phases. Phase I activities assessed the Liquid Waste inventory and chemical processing behavior using a system-by-system review methodology, and determined the speciation of the different mercury forms (Hg+, Hg++, elemental Hg, organomercury, and soluble versus insoluble mercury) within the LWS. Phase II activities are building on the Phase I activities, and results of the LWS flowsheet evaluations will be summarized in three reports: Mercury Behavior in the Salt Processing Flowsheet (i.e. this report); Mercury Behavior in the Defense Waste Processing Facility (DWPF) Flowsheet; and Mercury behavior in the Tank Farm Flowsheet (Evaporator Operations). The evaluation of the mercury behavior in the salt processing flowsheet indicates, inter alia, the following: (1) In the assembled Salt Batches 7, 8 and 9 in Tank 21, the total mercury is mostly soluble with methylmercury (MHg) contributing over 50% of the total mercury. Based on the analyses of samples from 2H Evaporator feed and drop tanks (Tanks 38/43), the source of MHg in Salt Batches 7, 8 and 9 can be attributed to the 2H evaporator concentrate used in assembling the salt batches. The 2H Evaporator is used to evaporate DWPF recycle water. (2) Comparison of data between Tank 21/49, Salt Solution Feed Tank (SSFT), Decontaminated Salt Solution Hold Tank (DSSHT), and Tank 50 samples suggests that the total mercury as well as speciated

  9. Reducing surface water total and methyl mercury concentrations and bioavailability using a coagulation-wetland system

    Science.gov (United States)

    Kraus, T. E.; Fleck, J.; Henneberry, Y. K.; Stumpner, E. B.; Krabbenhoft, D. P.; Bachand, P.; Randall, P.

    2013-12-01

    With the recent passage of laws regulating concentrations and loads of mercury (Hg) in surface waters, there is a need to develop management practices that will reduce the export of Hg from both point and non-point sources. Coagulation with metal based salts to remove particles and dissolved organic matter (DOM) from solution is a practice commonly employed by drinking water utilities. Because dissolved Hg is associated with particles and DOM, it follows that Hg should also be removed during the coagulation process and end up associated with the organo-metal precipitate, termed flocculate (floc). The effectiveness of iron- and aluminum-based coagulants for removing both inorganic and methyl mercury (IHg and MeHg, respectively) from solution was demonstrated in laboratory studies conducted on agricultural drainage waters of the Sacramento-San Joaquin Delta: dissolved concentrations of MeHg decreased by 80% while IHg decreased by 97% following coagulation. To test the field application of this technology, samples were collected from the inflows and outflows of wetland treatment cells constructed in the central Delta of California. This replicated field experiment includes three replicates each of three inflow waters treatments: (1) iron sulfate addition, (2) polyaluminum chloride addition, and (3) untreated controls. Water entering and exiting the nine treatment cells was sampled approximately monthly over a 1-year period for total Hg and MeHg in both the dissolved and particulate aqueous phases. Initial results confirm that coagulant addition is removing Hg (total and methyl, particulate and dissolved) from solution and sequestering it in the floc. Seasonal effects on DOM concentration and other factors appear to effect whether passage through the wetland cells alters surface water dissolved organic carbon (DOC) and Hg concentrations. Related studies will examine whether the presence of the floc affects the production and fate of MeHg within the wetland cells. If

  10. Solar System Exploration Augmented by In-Situ Resource Utilization: Human Planetary Base Issues for Mercury and Saturn

    Science.gov (United States)

    Palaszewski, Bryan A.

    2017-01-01

    Human and robotic missions to Mercury and Saturn are presented and analyzed with a range of propulsion options. Historical studies of space exploration, planetary spacecraft, and astronomy, in-situ resource utilization (ISRU), and industrialization all point to the vastness of natural resources in the solar system. Advanced propulsion benefitted from these resources in many ways. While advanced propulsion systems were proposed in these historical studies, further investigation of nuclear options using high power nuclear thermal and nuclear pulse propulsion as well as advanced chemical propulsion can significantly enhance these scenarios. Updated analyses based on these historical visions are presented. Nuclear thermal propulsion and ISRU enhanced chemical propulsion landers are assessed for Mercury missions. At Saturn, nuclear pulse propulsion with alternate propellant feed systems and Saturn moon exploration with chemical propulsion and nuclear electric propulsion options are discussed. Issues with using in-situ resource utilization on Mercury missions are discussed. At Saturn, the best locations for exploration and the use of the moons Titan and Enceladus as central locations for Saturn moon exploration is assessed.

  11. FABRIC QUALITY CONTROL SYSTEMS

    Directory of Open Access Journals (Sweden)

    Özlem KISAOĞLU

    2006-02-01

    Full Text Available Woven fabric quality depends on yarn properties at first, then weaving preparation and weaving processes. Defect control of grey and finished fabric is done manually on the lighted tables or automatically. Fabrics can be controlled by the help of the image analysis method. In image system the image of fabrics can be digitized by video camera and after storing controlled by the various processing. Recently neural networks, fuzzy logic, best wavelet packet model on automatic fabric inspection are developed. In this study the advantages and disadvantages of manual and automatic, on-line fabric inspection systems are given comparatively.

  12. Lighting Control System (ILCS)

    African Journals Online (AJOL)

    2017-08-08

    Aug 8, 2017 ... advanced control system for reducing the energy consumption of public street lighting systems, research by [20] analyzed ... This is accomplished by generating a square wave. The duty cycle of the .... luminosity sensor is an advanced digital light sensor, which ideal for use in a wide range of light situations.

  13. FMIT facility control system

    International Nuclear Information System (INIS)

    Suyama, R.M.; Machen, D.R.; Johnson, J.A.

    1981-01-01

    The control system for the Fusion Materials Irradiation Test (FMIT) Facility, under construction at Richland, Washington, uses current techniques in distributed processing to achieve responsiveness, maintainability and reliability. Developmental experience with the system on the FMIT Prototype Accelerator (FPA) being designed at the Los Alamos National Laboratory is described as a function of the system's design goals and details. The functional requirements of the FMIT control system dictated the use of a highly operator-responsive, display-oriented structure, using state-of-the-art console devices for man-machine communications. Further, current technology has allowed the movement of device-dependent tasks into the area traditionally occupied by remote input-output equipment; the system's dual central process computers communicate with remote communications nodes containing microcomputers that are architecturally similar to the top-level machines. The system has been designed to take advantage of commercially available hardware and software

  14. TMX magnet control system

    International Nuclear Information System (INIS)

    Goerz, D.A.

    1978-01-01

    A control system utilizing a microcomputer has been developed that controls the power supplies driving the Tandem Mirror Experiment (TMX) magnet set and monitors magnet coil operation. The magnet set consists of 18 magnet coils that are driven by 26 dc power supplies. There are two possible modes of operation with this system: a pulse mode where the coils are pulsed on for several seconds with a dc power consumption of 16 MW; and a continuous mode where the coils can run steady state at 10 percent of maximum current ratings. The processor has been given an active control role and serves as an interface between the operator and electronic circuitry that controls the magnet power supplies. This microcomputer also collects and processes data from many analog singal monitors in the coil circuits and numerous status signals from the supplies. Placing the microcomputer in an active control role has yielded a compact, cost effective system that simplifies the magnet system operation and has proven to be very reliable. This paper will describe the TMX magnet control sytem and discuss its development

  15. Mercury analysis and speciation: The potential role of the IAEA

    International Nuclear Information System (INIS)

    Horvat, Milena

    2001-01-01

    Owing to the toxicity of its methylated form, its accumulation in biota and biomagnification in the aquatic food chain, mercury has been at the centre of considerable attention. Inorganic mercury can be methylated by bacterial action and is stored in the muscle tissue of fish. When ingested by man, it can attack the central nervous system. The US Environmental Protection Agency has already set stringent guidelines for the maximum dietary intake of methyl mercury (0.1 μg/kg/day). Up to 10 million people are involved in the use of mercury in gold exploitation which constitutes a significant pollution source in some countries. The biogeochemistry of mercury and the mercury cycle were reviewed. Long range atmospheric transfer mechanisms have led to significant contamination of fish in lakes remote from any pollution source. The value of stable or radioactive isotopic tracers in understanding the mercury cycle was pointed out and the need for relevant natural matrix reference materials for quality control and method development purposes was stressed

  16. Neural Flight Control System

    Science.gov (United States)

    Gundy-Burlet, Karen

    2003-01-01

    The Neural Flight Control System (NFCS) was developed to address the need for control systems that can be produced and tested at lower cost, easily adapted to prototype vehicles and for flight systems that can accommodate damaged control surfaces or changes to aircraft stability and control characteristics resulting from failures or accidents. NFCS utilizes on a neural network-based flight control algorithm which automatically compensates for a broad spectrum of unanticipated damage or failures of an aircraft in flight. Pilot stick and rudder pedal inputs are fed into a reference model which produces pitch, roll and yaw rate commands. The reference model frequencies and gains can be set to provide handling quality characteristics suitable for the aircraft of interest. The rate commands are used in conjunction with estimates of the aircraft s stability and control (S&C) derivatives by a simplified Dynamic Inverse controller to produce virtual elevator, aileron and rudder commands. These virtual surface deflection commands are optimally distributed across the aircraft s available control surfaces using linear programming theory. Sensor data is compared with the reference model rate commands to produce an error signal. A Proportional/Integral (PI) error controller "winds up" on the error signal and adds an augmented command to the reference model output with the effect of zeroing the error signal. In order to provide more consistent handling qualities for the pilot, neural networks learn the behavior of the error controller and add in the augmented command before the integrator winds up. In the case of damage sufficient to affect the handling qualities of the aircraft, an Adaptive Critic is utilized to reduce the reference model frequencies and gains to stay within a flyable envelope of the aircraft.

  17. Estimates of increased black carbon emissions from electrostatic precipitators during powdered activated carbon injection for mercury emissions control.

    Science.gov (United States)

    Clack, Herek L

    2012-07-03

    The behavior of mercury sorbents within electrostatic precipitators (ESPs) is not well-understood, despite a decade or more of full-scale testing. Recent laboratory results suggest that powdered activated carbon exhibits somewhat different collection behavior than fly ash in an ESP and particulate filters located at the outlet of ESPs have shown evidence of powdered activated carbon penetration during full-scale tests of sorbent injection for mercury emissions control. The present analysis considers a range of assumed differential ESP collection efficiencies for powdered activated carbon as compared to fly ash. Estimated emission rates of submicrometer powdered activated carbon are compared to estimated emission rates of particulate carbon on submicrometer fly ash, each corresponding to its respective collection efficiency. To the extent that any emitted powdered activated carbon exhibits size and optical characteristics similar to black carbon, such emissions could effectively constitute an increase in black carbon emissions from coal-based stationary power generation. The results reveal that even for the low injection rates associated with chemically impregnated carbons, submicrometer particulate carbon emissions can easily double if the submicrometer fraction of the native fly ash has a low carbon content. Increasing sorbent injection rates, larger collection efficiency differentials as compared to fly ash, and decreasing sorbent particle size all lead to increases in the estimated submicrometer particulate carbon emissions.

  18. System control and display

    International Nuclear Information System (INIS)

    Jacobs, J.

    1977-01-01

    The system described was designed, developed, and installed on short time scales and primarily utilized of-the-shelf military and commercial hardware. The system was designed to provide security-in-depth and multiple security options with several stages of redundancy. Under normal operating conditions, the system is computer controlled with manual backup during abnormal conditions. Sensor alarm data are processed in conjunction with weather data to reduce nuisance alarms. A structured approach is used to order alarmed sectors for assessment. Alarm and video information is presented to security personnel in an interactive mode. Historical operational data are recorded for system evaluation

  19. LONG-TERM DEMONSTRATION OF SORBENT ENHANCEMENT ADDITIVE TECHNOLOGY FOR MERCURY CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Jason D. Laumb; Dennis L. Laudal; Grant E. Dunham; John P. Kay; Christopher L. Martin; Jeffrey S. Thompson; Nicholas B. Lentz; Alexander Azenkeng; Kevin C. Galbreath; Lucinda L. Hamre

    2011-05-27

    Long-term demonstration tests of advanced sorbent enhancement additive (SEA) technologies have been completed at five coal-fired power plants. The targeted removal rate was 90% from baseline conditions at all five stations. The plants included Hawthorn Unit 5, Mill Creek Unit 4, San Miguel Unit 1, Centralia Unit 2, and Hoot Lake Unit 2. The materials tested included powdered activated carbon, treated carbon, scrubber additives, and SEAs. In only one case (San Miguel) was >90% removal not attainable. The reemission of mercury from the scrubber at this facility prevented >90% capture.

  20. Study on emission of hazardous trace elements in a 350 MW coal-fired power plant. Part 1. Mercury.

    Science.gov (United States)

    Zhao, Shilin; Duan, Yufeng; Chen, Lei; Li, Yaning; Yao, Ting; Liu, Shuai; Liu, Meng; Lu, Jianhong

    2017-10-01

    Hazardous trace elements (HTEs), especially mercury, emitted from coal-fired power plants had caused widespread concern worldwide. Field test on mercury emissions at three different loads (100%, 85%, 68% output) using different types of coal was conducted in a 350 MW pulverized coal combustion power plant equipped with selective catalytic reduction (SCR), electrostatic precipitator and fabric filter (ESP + FF), and wet flue gas desulfurization (WFGD). The Ontario Hydro Method was used for simultaneous flue gas mercury sampling for mercury at the inlet and outlet of each of the air pollutant control device (APCD). Results showed that mercury mass balance rates of the system or each APCD were in the range of 70%-130%. Mercury was mainly distributed in the flue gas, followed by ESP + FF ash, WFGD wastewater, and slag. Oxidized mercury (Hg 2+ ) was the main form of mercury form in the flue gas emitted to the atmosphere, which accounted for 57.64%-61.87% of total mercury. SCR was favorable for elemental mercury (Hg 0 ) removal, with oxidation efficiency of 50.13%-67.68%. ESP + FF had high particle-bound mercury (Hg p ) capture efficiency, at 99.95%-99.97%. Overall removal efficiency of mercury by the existing APCDs was 58.78%-73.32%. Addition of halogens or oxidants for Hg 0 conversion, and inhibitors for Hg 0 re-emission, plus the installation of a wet electrostatic precipitator (WESP) was a good way to improve the overall removal efficiency of mercury in the power plants. Mercury emission factor determined in this study was from 0.92 to 1.17 g/10 12 J. Mercury concentration in the emitted flue gas was much less than the regulatory limit of 30 μg/m 3 . Contamination of mercury in desulfurization wastewater should be given enough focus. Copyright © 2017. Published by Elsevier Ltd.

  1. Mercury transformations in resuspended contaminated sediment controlled by redox conditions, chemical speciation and sources of organic matter

    Science.gov (United States)

    Zhu, Wei; Song, Yu; Adediran, Gbotemi A.; Jiang, Tao; Reis, Ana T.; Pereira, Eduarda; Skyllberg, Ulf; Björn, Erik

    2018-01-01

    Mercury (Hg) contaminated sediments can be significant sources of Hg in aquatic ecosystems and, through re-emission processes, to the atmosphere. Transformation and release of Hg may be enhanced by various sediment perturbation processes, and controlling biogeochemical factors largely remain unclear. We investigated how rates of Hg transformations in pulp-fiber enriched sediment contaminated by Hg from chlor-alkali industry were controlled by (i) transient redox-changes in sulfur and iron chemistry, (ii) the chemical speciation and solubility of Hg, and (iii) the sources and characteristics of organic matter (OM). Sediment-bottom water microcosm systems were exposed to four combinations of air and nitrogen gas for a total time of 24 h. The treatments were: 24 h N2, 0.5 h air + 23.5 h N2, 4 h air + 20 h N2 and 24 h of air exposure. As a result of these treatments, microcosms spanned a wide range of redox potential, as reflected by the dissolved sulfide concentration range of ≤0.3-97 μM. Four different chemical species of inorganic divalent Hg (HgII) and methyl mercury (MeHg), enriched in different Hg isotope tracers, were added to the microcosms: 201Hg(NO3)2(aq), 202HgII adsorbed to OM (202HgII-OM(ads)), 198HgII as microcrystalline metacinnabar (β-198HgS(s)) and Me204HgCl(aq). Microcosm systems were composed of bottom water mixed with sediment taken at 0-2, 0-5 and 0-10 cm depth intervals. The composition of OM varied with sediment depth such that compared to deeper sediment, the 0-2 cm depth-interval had a 2-fold higher contribution of labile OM originating from algal and terrestrial inputs, serving as metabolic electron-donors for microorganisms. The potential methylation rate constant (kmeth) of Hg tracers and net formation of ambient MeHg (MeHg/THg molar ratio) increased up to 50% and 400%, respectively at intermediate oxidative conditions, likely because of an observed 2-fold increase in sulfate concentration stimulating the activity of sulfate reducing

  2. The TRISTAN control system

    International Nuclear Information System (INIS)

    Kurokawa, Shinichi; Akiyama, Atsuyoshi; Ishii, Kazuhiro; Kadokura, Eiichi; Katoh, Tadahiko; Kawamoto, Takashi; Kikutani, Eiji; Kimura, Yoshitaka; Koiso, Haruyo; Komada, Ichitaka; Kudo, Kikuo; Naito, Takashi; Oide, Katsunobu; Takeda, Shigeru; Uchino, Kenji; Urakawa, Junji; Shinomoto, Manabu; Kurihara, Michio; Abe, Kenichi

    1986-01-01

    The 8 GeV accumulation ring and the 30 GeV main ring of TRISTAN, an accelerator-storage ring complex at KEK, are controlled by a highly computerized control system. Twenty-four minicomputers are linked by optical fiber cables to form an N-to-N token ring network. The transmission speed on the cables is 10 Mbps. From each minicomputer, a CAMAC serial highway extends to the controlled equipment. At present, twenty minicomputers are connected to the network and are used to control the accumulation ring. The software system is based on the NODAL language devised at the CERN SPS. The KEK NODAL system retains main features of the original NODAL: the interpretive scheme, the multi-computer programming facility, and the data-module concept. In addition, it has the following features: (1) fast execution due to the compiler-interpreter method, (2) a multi-computer file system (3), a full-screen editing facility, and (4) a dynamic linkage scheme for data modules and NODAL functions. The accelerators are operated through five operator consoles, each of which is mangaged by one minicomputer in the network. An operator console contains two 20-inch high-resolution color graphic displays, a pair of touch-panels, and ten small TV monitors. One touch-panel is used to select a program and a piece of equipment to be controlled; the other is used mainly to perform the console actions. (orig.)

  3. neural control system

    International Nuclear Information System (INIS)

    Elshazly, A.A.E.

    2002-01-01

    Automatic power stabilization control is the desired objective for any reactor operation , especially, nuclear power plants. A major problem in this area is inevitable gap between a real plant ant the theory of conventional analysis and the synthesis of linear time invariant systems. in particular, the trajectory tracking control of a nonlinear plant is a class of problems in which the classical linear transfer function methods break down because no transfer function can represent the system over the entire operating region . there is a considerable amount of research on the model-inverse approach using feedback linearization technique. however, this method requires a prices plant model to implement the exact linearizing feedback, for nuclear reactor systems, this approach is not an easy task because of the uncertainty in the plant parameters and un-measurable state variables . therefore, artificial neural network (ANN) is used either in self-tuning control or in improving the conventional rule-based exper system.the main objective of this thesis is to suggest an ANN, based self-learning controller structure . this method is capable of on-line reinforcement learning and control for a nuclear reactor with a totally unknown dynamics model. previously, researches are based on back- propagation algorithm . back -propagation (BP), fast back -propagation (FBP), and levenberg-marquardt (LM), algorithms are discussed and compared for reinforcement learning. it is found that, LM algorithm is quite superior

  4. Bench-scale Kinetics Study of Mercury Reactions in FGD Liquors

    Energy Technology Data Exchange (ETDEWEB)

    Gary Blythe; John Currie; David DeBerry

    2008-03-31

    This document is the final report for Cooperative Agreement DE-FC26-04NT42314, 'Kinetics Study of Mercury Reactions in FGD Liquors'. The project was co-funded by the U.S. DOE National Energy Technology Laboratory and EPRI. The objective of the project has been to determine the mechanisms and kinetics of the aqueous reactions of mercury absorbed by wet flue gas desulfurization (FGD) systems, and develop a kinetics model to predict mercury reactions in wet FGD systems. The model may be used to determine optimum wet FGD design and operating conditions to maximize mercury capture in wet FGD systems. Initially, a series of bench-top, liquid-phase reactor tests were conducted and mercury species concentrations were measured by UV/visible light spectroscopy to determine reactant and byproduct concentrations over time. Other measurement methods, such as atomic absorption, were used to measure concentrations of vapor-phase elemental mercury, that cannot be measured by UV/visible light spectroscopy. Next, a series of bench-scale wet FGD simulation tests were conducted. Because of the significant effects of sulfite concentration on mercury re-emission rates, new methods were developed for operating and controlling the bench-scale FGD experiments. Approximately 140 bench-scale wet FGD tests were conducted and several unusual and pertinent effects of process chemistry on mercury re-emissions were identified and characterized. These data have been used to develop an empirically adjusted, theoretically based kinetics model to predict mercury species reactions in wet FGD systems. The model has been verified in tests conducted with the bench-scale wet FGD system, where both gas-phase and liquid-phase mercury concentrations were measured to determine if the model accurately predicts the tendency for mercury re-emissions. This report presents and discusses results from the initial laboratory kinetics measurements, the bench-scale wet FGD tests, and the kinetics modeling

  5. News from Front (of the Solar System): the problem with Mercury, the Vulcan hypothesis, and General Relativity's first astronomical triumph

    Science.gov (United States)

    Sheehan, William

    2016-01-01

    The discovery of the outer planet Neptune in 1846, based on the calculated position published by Urbain Jean Joseph Le Verrier, has been hailed as the "zenith of Newtonian mechanics." An attempt by Le Verrier to further extend the dominion of Newton's gravitational theory to the innermost known planet of the Solar System, Mercury, seemingly came to grief with the discovery of a small unexplained discrepancy in the precession of the perihelion of Mercury, whose value was later calculated as 43".0 per century. Le Verrier proposed that it could be explained on the basis of Newtonian theory by assuming the existence of an intra-mercurial planet ("Vulcan") or ring of debris. Efforts to confirm this hypothesis, culminating in high drama on the plains of the western United States at the great North American solar eclipse of July 1878, proved futile; by 1908, W. W. Campbell and C.D. Perrine of Lick Observatory, who had carried out exhaustive photographic searches at three eclipses (1901, 1905, and 1908) could declare that Vulcan did not exist. The theoretical problem it was invoked to explain remained until November 1915, when Albert Einstein used the recently discovered generally covariant gravitational equations to put the problem to rest. "Perihelion motions explained quantitatively … you will be astonished," he wrote to his friend Michael Besso.

  6. Measurement of atmospheric mercury species with manual sampling and analysis methods in a case study in Indiana

    Science.gov (United States)

    Risch, M.R.; Prestbo, E.M.; Hawkins, L.

    2007-01-01

    Ground-level concentrations of three atmospheric mercury species were measured using manual sampling and analysis to provide data for estimates of mercury dry deposition. Three monitoring stations were operated simultaneously during winter, spring, and summer 2004, adjacent to three mercury wet-deposition monitoring stations in northern, central, and southern Indiana. The monitoring locations differed in land-use setting and annual mercury-emissions level from nearby sources. A timer-controlled air-sampling system that contained a three-part sampling train was used to isolate reactive gaseous mercury, particulate-bound mercury, and elemental mercury. The sampling trains were exchanged every 6 days, and the mercury species were quantified in a laboratory. A quality-assurance study indicated the sampling trains could be held at least 120 h without a significant change in reactive gaseous or particulate-bound mercury concentrations. The manual sampling method was able to provide valid mercury concentrations in 90 to 95% of samples. Statistical differences in mercury concentrations were observed during the project. Concentrations of reactive gaseous and elemental mercury were higher in the daytime samples than in the nighttime samples. Concentrations of reactive gaseous mercury were higher in winter than in summer and were highest at the urban monitoring location. The results of this case study indicated manual sampling and analysis could be a reliable method for measurement of atmospheric mercury species and has the capability for supplying representative concentrations in an effective manner from a long-term deposition-monitoring network. ?? 2007 Springer Science+Business Media B.V.

  7. Control of complex systems

    CERN Document Server

    Albertos, Pedro; Blanke, Mogens; Isidori, Alberto; Schaufelberger, Walter; Sanz, Ricardo

    2001-01-01

    The world of artificial systems is reaching complexity levels that es­ cape human understanding. Surface traffic, electricity distribution, air­ planes, mobile communications, etc. , are examples that demonstrate that we are running into problems that are beyond classical scientific or engi­ neering knowledge. There is an ongoing world-wide effort to understand these systems and develop models that can capture its behavior. The reason for this work is clear, if our lack of understanding deepens, we will lose our capability to control these systems and make they behave as we want. Researchers from many different fields are trying to understand and develop theories for complex man-made systems. This book presents re­ search from the perspective of control and systems theory. The book has grown out of activities in the research program Control of Complex Systems (COSY). The program has been sponsored by the Eu­ ropean Science Foundation (ESF) which for 25 years has been one of the leading players in stimula...

  8. Field controlled experiments of mercury accumulation in crops from air and soil

    Energy Technology Data Exchange (ETDEWEB)

    Niu Zhenchuan [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Zhang Xiaoshan, E-mail: zhangxsh@rcees.ac.cn [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Wang Zhangwei, E-mail: wangzhw@rcees.ac.cn [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Ci Zhijia [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China)

    2011-10-15

    Field open top chambers (OTCs) and soil mercury (Hg) enriched experiments were employed to study the influence of Hg concentrations in air and soil on the Hg accumulation in the organs of maize (Zea mays L.) and wheat (Triticum aestivum L.). Results showed that Hg concentrations in foliages were correlated significantly (p < 0.05) with air Hg concentrations but insignificantly correlated with soil Hg concentrations, indicating that Hg in crop foliages was mainly from air. Hg concentrations in roots were generally correlated with soil Hg concentrations (p < 0.05) but insignificantly correlated with air Hg concentrations, indicating that Hg in crop roots was mainly from soil. No significant correlations were found between Hg concentrations in stems and those in air and soil. However, Hg concentrations in upper stems were usually higher than those in bottom stems, implying air Hg might have stronger influence than soil Hg on stem Hg accumulation. - Highlights: > Hg accumulation in crop organs was studied by OTCs and soil Hg enriched experiments. > Hg accumulation in foliages and roots was mainly from air and soil, respectively. > Air Hg had stronger influence than soil Hg on stem Hg accumulation. > Foliar Hg concentrations showed the trend of increase over growth stages. - Capsule Mercury accumulated in the aboveground organs of crop was mainly from the air.

  9. Field controlled experiments of mercury accumulation in crops from air and soil

    International Nuclear Information System (INIS)

    Niu Zhenchuan; Zhang Xiaoshan; Wang Zhangwei; Ci Zhijia

    2011-01-01

    Field open top chambers (OTCs) and soil mercury (Hg) enriched experiments were employed to study the influence of Hg concentrations in air and soil on the Hg accumulation in the organs of maize (Zea mays L.) and wheat (Triticum aestivum L.). Results showed that Hg concentrations in foliages were correlated significantly (p < 0.05) with air Hg concentrations but insignificantly correlated with soil Hg concentrations, indicating that Hg in crop foliages was mainly from air. Hg concentrations in roots were generally correlated with soil Hg concentrations (p < 0.05) but insignificantly correlated with air Hg concentrations, indicating that Hg in crop roots was mainly from soil. No significant correlations were found between Hg concentrations in stems and those in air and soil. However, Hg concentrations in upper stems were usually higher than those in bottom stems, implying air Hg might have stronger influence than soil Hg on stem Hg accumulation. - Highlights: → Hg accumulation in crop organs was studied by OTCs and soil Hg enriched experiments. → Hg accumulation in foliages and roots was mainly from air and soil, respectively. → Air Hg had stronger influence than soil Hg on stem Hg accumulation. → Foliar Hg concentrations showed the trend of increase over growth stages. - Capsule Mercury accumulated in the aboveground organs of crop was mainly from the air.

  10. A vegetation control on seasonal variations in global atmospheric mercury concentrations

    Science.gov (United States)

    Jiskra, Martin; Sonke, Jeroen E.; Obrist, Daniel; Bieser, Johannes; Ebinghaus, Ralf; Myhre, Cathrine Lund; Pfaffhuber, Katrine Aspmo; Wängberg, Ingvar; Kyllönen, Katriina; Worthy, Doug; Martin, Lynwill G.; Labuschagne, Casper; Mkololo, Thumeka; Ramonet, Michel; Magand, Olivier; Dommergue, Aurélien

    2018-04-01

    Anthropogenic mercury emissions are transported through the atmosphere as gaseous elemental mercury (Hg(0)) before they are deposited to Earth's surface. Strong seasonality in atmospheric Hg(0) concentrations in the Northern Hemisphere has been explained by two factors: anthropogenic Hg(0) emissions are thought to peak in winter due to higher energy consumption, and atmospheric oxidation rates of Hg(0) are faster in summer. Oxidation-driven Hg(0) seasonality should be equally pronounced in the Southern Hemisphere, which is inconsistent with observations of constant year-round Hg(0) levels. Here, we assess the role of Hg(0) uptake by vegetation as an alternative mechanism for driving Hg(0) seasonality. We find that at terrestrial sites in the Northern Hemisphere, Hg(0) co-varies with CO2, which is known to exhibit a minimum in summer when CO2 is assimilated by vegetation. The amplitude of seasonal oscillations in the atmospheric Hg(0) concentration increases with latitude and is larger at inland terrestrial sites than coastal sites. Using satellite data, we find that the photosynthetic activity of vegetation correlates with Hg(0) levels at individual sites and across continents. We suggest that terrestrial vegetation acts as a global Hg(0) pump, which can contribute to seasonal variations of atmospheric Hg(0), and that decreasing Hg(0) levels in the Northern Hemisphere over the past 20 years can be partly attributed to increased terrestrial net primary production.

  11. Controlling mercury and selenium emissions from coal-fired combustors using a novel regenerable natural product

    Energy Technology Data Exchange (ETDEWEB)

    Schlager, R.J.; Marmaro, R.W.; Roberts, D.L. [ADA Technologies, Inc., Englewood, CO (United States)

    1995-11-01

    This program successfully demonstrated the key components that are needed for a practical, regenerable sorption process for removing and recovering mercury from flue gas streams: (1) a proprietary natural product removed mercuric chloride from synthetic flue gas, (2) several new noble metal sorbents were shown to capture elemental gas-phase mercury from synthetic coal combustion flue gas, and (3) both the natural product and the noble metal sorbents could be regenerated in the laboratory (chemical method for the natural product, thermal method for noble metal sorbents). Several sorbents were tested for their ability to collect selenium oxide during the program. These tests, however, were not definitive due to inconclusive analytical results. If follow-on testing is funded, the ability of the proposed sorbents to collect selenium and other metals will be evaluated during the field testing phase of the program. A preliminary economic analysis indicates that the cost of the process appears to be substantially less than the cost of the state-of-the-art method, namely injection of activated carbon, and it also appears to cost less than using noble metal sorbents alone.

  12. Investigation and demonstration of dry carbon-based sorbent injection for mercury control. Quarterly technical report, July 1, 1996--September 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, T.; Sjostrom, S.; Smith, J. [and others

    1996-11-06

    The overall objective of this two phase program is to investigate the use of dry carbon-based sorbents for mercury control. This information is important to the utility industry in anticipation of pending regulations. During Phase I, a bench-scale field test device that can be configured as an electrostatic precipitator, a pulse-jet baghouse, or a reverse-gas baghouse has been designed, built and integrated with an existing pilot-scale facility at PSCo`s Comanche Station. Up to three candidate sorbents will be injected into the flue gas stream upstream of the test device to and mercury concentration measurements will be made to determine the mercury removal efficiency for each sorbent. During the Phase II effort, component integration for the most promising dry sorbent technology shall be tested at the 5000 acfm pilot-scale.

  13. Nonlinear Control System

    Directory of Open Access Journals (Sweden)

    Jaydeep Jesur

    2000-01-01

    and features are added such a way that it can be also used for design of nonlinear control systems to achieve desired performance. It is very simple to learn this tool. One can easily use it with preliminary knowledge of DF and PPT methods.

  14. HESYRL control system status

    International Nuclear Information System (INIS)

    Yao Chihyuan

    1992-01-01

    HESYRL synchrotron radiation storage ring was completed in 1989 and has been in commissioning since then. Now it has met its design specification and is ready for synchrotron light experiments. Control system of the project was completed in 1989 and some modifications were made during commissioning. This paper describes its present configuration, status and upgrading plan. (author)

  15. Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 3 Full-scale Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Gary Blythe

    2007-05-01

    This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of a flue gas desulfurization (FGD) additive, Degussa Corporation's TMT-15, to prevent the reemission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine TMT salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project is conducting pilot- and full-scale tests of the TMT-15 additive in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} reemissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Power River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, TXU Generation Company LP, Southern Company, and Degussa Corporation. TXU Generation has provided the Texas lignite/PRB cofired test site for pilot FGD tests, Monticello Steam Electric Station Unit 3. Southern Company is providing the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems to be tested. IPL, an AES company, provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Degussa Corporation is providing the TMT-15 additive and technical support to the test program as cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6 involves management and reporting. The other four tasks involve field testing on FGD systems, either at pilot or full scale. The four tasks include: Task 2 - Pilot

  16. Autometallographic tracing of mercury in frog liver

    International Nuclear Information System (INIS)

    Loumbourdis, N.S.; Danscher, G.

    2004-01-01

    The distribution of mercury in the liver of the frog Rana ridibunda with the autometallographic method was investigated. The mercury specific autometallographic (HgS/Se AMG ) technique is a sensitive histochemical approach for tracing mercury in tissues from mercury-exposed organisms. Mercury accumulates in vivo as mercury sulphur/mercury selenium nanocrystals that can be silver-enhanced. Thus, only a fraction of the Hg can be visualized. Six animals were exposed for one day and another group of six animals for 6 days in 1 ppm mercury (as HgCI 2 ) dissolved in fresh water. A third group of six animals, served as controls, were sacrificed the day of arrival at the laboratory. First, mercury appears in the blood plasma and erythrocytes. Next, mercury moves to hepatocytes and in the apical part of the cells, that facing bile canaliculi. In a next step, mercury appears in the endothelial and Kupffer cells. It seems likely that, the mercury of hepatocytes moves through bile canaliculi to the gut, most probably bound to glutathione and/or other similar ligands. Most probably, the endothelial and Kupffer cells comprise the first line of defense against metal toxicity. - Frogs can be good bioindicators of mercury

  17. PEP computer control system

    International Nuclear Information System (INIS)

    1979-03-01

    This paper describes the design and performance of the computer system that will be used to control and monitor the PEP storage ring. Since the design is essentially complete and much of the system is operational, the system is described as it is expected to 1979. Section 1 of the paper describes the system hardware which includes the computer network, the CAMAC data I/O system, and the operator control consoles. Section 2 describes a collection of routines that provide general services to applications programs. These services include a graphics package, data base and data I/O programs, and a director programm for use in operator communication. Section 3 describes a collection of automatic and semi-automatic control programs, known as SCORE, that contain mathematical models of the ring lattice and are used to determine in real-time stable paths for changing beam configuration and energy and for orbit correction. Section 4 describes a collection of programs, known as CALI, that are used for calibration of ring elements

  18. Modified Dietary Fiber from Cassava Pulp and Assessment of Mercury Bioaccessibility and Intestinal Uptake Using an In Vitro Digestion/Caco-2 Model System.

    Science.gov (United States)

    Kachenpukdee, Natta; Santerre, Charles R; Ferruzzi, Mario G; Oonsivilai, Ratchadaporn

    2016-07-01

    The ability of modified dietary fiber (MDF) generated from cassava pulp to modulate the bioaccessibility and intestinal absorption of heavy metals may be helpful to mitigate health risk associated with select foods including select fish high in methyl mercury. Using a coupled in vitro digestion/Caco-2 human intestinal cell model, the reduction of fish mercury bioaccessibility and intestinal uptake by MDF was investiaged. MDF was prepared from cassava pulp, a byproduct of tapioca production. The highest yield (79.68%) of MDF was obtained by enzymatic digestion with 0.1% α-amylase (w/v), 0.1% amyloglucosidase (v/v) and 1% neutrase (v/v). MDF and fish tissue were subjected to in vitro digestion and results suggest that MDF may reduce mercury bioaccessibility from fish to 34% to 85% compared to control in a dose-dependent manner. Additionally, accumulation of mercury from digesta containing fish and MDF was only modestly impacted by the presence of MDF. In conclusion, MDF prepared from cassava pulp may be useful as an ingredient to reduce mercury bioavailability from food such as fish specifically by inhibiting mercury transfer to the bioaccessibile fraction during digestion. © 2016 Institute of Food Technologists®

  19. Mercury Methylation, Demethylation, and Bioavailability in the Hyporheic Sediments of a Northern Wisconsin Wetland

    Science.gov (United States)

    Creswell, J. E.; Babiarz, C. L.; Shafer, M. M.; Roden, E. E.; Armstrong, D. E.

    2007-12-01

    It is generally accepted that wetland sediments have a high potential to produce methylmercury, yet the factors controlling the relevant chemical transformations are poorly understood. Previous studies suggest that sulfate- reducing bacteria play an important role in methylation, but iron-reducing bacteria may also participate in this process. Methylation rates are influenced by both the concentration of Hg(II) and its speciation, which affects its bioavailability. Net accumulation depends also on demethylation rates, rates which may be significant in these systems. The objective of this study is to gain a better understanding of the main factors controlling the bioavailability of inorganic mercury for the production of methylmercury in wetland hyporheic zones. Stable isotopes of mercury are being used to investigate potential methylation and demethylation rates in the hyporheic sediments of Allequash Creek, near Boulder Junction, WI. Other techniques that are being applied to examine the chemical and biological drivers of mercury methylation and bioavailability include tin-reducible mercury "titrations" to measure the concentration of strong mercury-binding ligands in porewater, 14C-acetate uptake assays to determine the activity of the native microbial consortia , ion exchange resin experiments to explore the role of dissolved organic carbon in mercury binding, and inhibition studies (e.g. molybdenum amendments) of sulfate-reducing bacteria to assess their role in producing methylmercury. Manipulations of environmental conditions in laboratory microcosms are used to determine the relative importance of physical factors, such as temperature, and biogeochemical factors, such as sulfate, sulfide, dissolved organic carbon (DOC), and iron levels, on the fate of mercury in hyporheic systems. Preliminary results show that while significant levels of inorganic mercury are present in the hyporheic groundwater, strong mercury-binding ligands in the wetland porewaters at a

  20. 21 CFR 880.2920 - Clinical mercury thermometer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Clinical mercury thermometer. 880.2920 Section 880... Devices § 880.2920 Clinical mercury thermometer. (a) Identification. A clinical mercury thermometer is a... mercury. (b) Classification. Class II (special controls). The device is exempt from the premarket...

  1. Mercury: Exploration of a Planet

    Science.gov (United States)

    1976-01-01

    The flight of the Mariner 10 spacecraft to Venus and Mercury is detailed in animation and photography. Views of Mercury are featured. Also included is animation on the origin of the solar system. Dr. Bruce C. Murray, director of the Jet Propulsion Laboratory, comments on the mission.

  2. Wireless Remote Control System

    Directory of Open Access Journals (Sweden)

    Adrian Tigauan

    2012-06-01

    Full Text Available This paper presents the design of a wireless remote control system based on the ZigBee communication protocol. Gathering data from sensors or performing control tasks through wireless communication is advantageous in situations in which the use of cables is impractical. An Atmega328 microcontroller (from slave device is used for gathering data from the sensors and transmitting it to a coordinator device with the help of the XBee modules. The ZigBee standard is suitable for low-cost, low-data-rate and low-power wireless networks implementations. The XBee-PRO module, designed to meet ZigBee standards, requires minimal power for reliable data exchange between devices over a distance of up to 1600m outdoors. A key component of the ZigBee protocol is the ability to support networking and this can be used in a wireless remote control system. This system may be employed e.g. to control temperature and humidity (SHT11 sensor and light intensity (TSL230 sensor levels inside a commercial greenhouse.

  3. Access control system operation

    International Nuclear Information System (INIS)

    Barnes, L.D.

    1981-06-01

    An automated method for the control and monitoring of personnel movement throughout the site was developed under contract to the Department of Energy by Allied-General Nuclear Services (AGNS) at the Barnwell Nuclear Fuel Plant (BNFP). These automated features provide strict enforcement of personnel access policy without routine patrol officer involvement. Identification methods include identification by employee ID number, identification by voice verification and identification by physical security officer verification. The ability to grant each level of access authority is distributed over the organization to prevent any single individual at any level in the organization from being capable of issuing an authorization for entry into sensitive areas. Each access event is recorded. As access events occur, the inventory of both the entered and the exited control area is updated so that a current inventory is always available for display. The system has been operated since 1979 in a development mode and many revisions have been implemented in hardware and software as areas were added to the system. Recent changes have involved the installation of backup systems and other features required to achieve a high reliability. The access control system and recent operating experience are described

  4. MEGARA Control System

    Science.gov (United States)

    Castillo-Morales, A.; Eliche-Moral, M. C.; Pascual, S.; Villar, V.; Marino, R. A.; Cardiel, N.; Morales, I.; González, E.; Cedazo, R.; Serena, F.; Gallego, J.; Carrasco, E.; Vílchez, J. M.; Sánchez, F. M.; Gil de Paz, A.; García-Vargas, M. L.; The Megara Team

    2013-05-01

    MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is an optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) designed for the GTC 10.4 m telescope in La Palma. The MEGARA Control System will provide the capabilities to move the different mechanisms of the instrument, to readout the data from the detector controller and the necessary routines for the Inspector Panels, the MEGARA Observing Preparation Software Suite, the Data Factory and the Sequencer strategies.

  5. Evaluation of Control Strategies to Effectively Meet 70-90% Mercury Reduction on an Eastern Bituminous Coal Cyclone Boiler with SCR

    Energy Technology Data Exchange (ETDEWEB)

    Tom Campbell

    2008-12-31

    This is the final site report for testing conducted at Public Service of New Hampshire's (PSNH) Merrimack Unit 2 (MK2). This project was funded through the DOE/NETL Innovations for Existing Plants program. It was a Phase III project with the goal to develop mercury control technologies that can achieve 50-70% mercury capture at costs 25-50% less than baseline estimates of $50,000-$70,000/lb of mercury removed. While results from testing at Merrimack indicate that the DOE goal was partially achieved, further improvements in the process are recommended. Merrimack burned a test blend of eastern bituminous and Venezuelan coals, for a target coal sulfur content of 1.2%, in its 335-MW Unit 2. The blend ratio is approximately a 50/50 split between the two coals. Various sorbent injection tests were conducted on the flue gas stream either in front of the air preheater (APH) or in between the two in-series ESPs. Initial mercury control evaluations indicated that, without SO3 control, the sorbent concentration required to achieve 50% control would not be feasible, either economically or within constraints specific to the maximum reasonable particle loading to the ESP. Subsequently, with SO{sub 3} control via trona injection upstream of the APH, economically feasible mercury removal rates could be achieved with PAC injection, excepting balance-of-plant concerns. The results are summarized along with the impacts of the dual injection process on the air heater, ESP operation, and particulate emissions.

  6. The extent of the influence and flux estimation of volatile mercury from the aeration pool in a typical coal-fired power plant equipped with a seawater flue gas desulfurization system

    International Nuclear Information System (INIS)

    Sun, Lumin; Feng, Lifeng; Yuan, Dongxing; Lin, Shanshan; Huang, Shuyuan; Gao, Liangming; Zhu, Yong

    2013-01-01

    Before being discharged, the waste seawater from the flue gas desulfurization system of coal-fired power plants contains a large amount of mercury, and is treated in aeration pools. During this aeration process, part of the mercury enters the atmosphere, but only very limited impact studies concerning this have been carried out. Taking a typical Xiamen power plant as an example, the present study targeted the elemental mercury emitted from the aeration pool. Concentrations of dissolved gaseous mercury as high as 1.14 ± 0.17 ng·L −1 were observed in the surface waste seawater in the aeration pool, and gaseous elemental mercury (GEM) as high as 10.94 ± 1.89 ng·m −3 was found in the air above the pool. To investigate the area affected by this GEM through air transfer, the total mercury in the dust and topsoil samples around the aeration pool were analyzed. Much higher values were found compared to those at a reference site. Environmental factors other than solar radiation had limited influence on the concentrations of the mercury species in the pool. A simulation device was built in our laboratory to study the flux of mercury from the aeration pool into the air. The results showed that more than 0.59 kg of mercury was released from the aeration pool every year, occupying 0.3% of the total mercury in the waste seawater. The transfer of mercury from water to air during the aeration pool and its environmental influence should not be ignored. - Highlights: ► High concentration of volatile mercury was observed in the aeration pool. ► More than 0.3% of total discharged Hg emitted from the pool into the air. ► Higher aeration rate resulted in more mercury emitted into the air. ► The dust and topsoil around the pool were polluted with the mercury

  7. Mercury and Pregnancy

    Science.gov (United States)

    ... Home > Pregnancy > Is it safe? > Mercury and pregnancy Mercury and pregnancy E-mail to a friend Please ... vision problems. How can you be exposed to mercury? Mercury has several forms: It can be a ...

  8. The UNK control system

    International Nuclear Information System (INIS)

    Alferov, V.N.; Brook, V.L.; Dunaitsev, A.F.

    1992-01-01

    The IHEP proton Accelerating and Storage Complex (UNK) includes in its first stage a 400 GeV conventional and a 3000 GeV superconducting ring placed in the same underground tunnel of 20.7 km circumference. The beam will be injected into UNK from the existing 70 GeV accelerator U-70. The experimental programme which is planned to start in 1995, will include 3000 GeV fixed target and 400 + 3000 GeV colliding beams physics. The size and complexity of the UNK dictate a distributed multiprocessor architecture of the control system. About 4000 of 8/16 bit controllers, directly attached to the UNK equipment will perform low level control and data acquisition tasks. The equipment controllers will be connected via the MIL-1553 field bus to VME based 32-bit front end computers. The TCP/IP network will interconnect front end computers in the UNK equipment buildings with UNIX workstations and servers in the Main Control Room. The report presents the general architecture and current status of the UNK control. (author)

  9. Intelligent Lighting Control System

    OpenAIRE

    García, Elena; Rodríguez González, Sara; de Paz Santana, Juan F.; Bajo Pérez, Javier

    2014-01-01

    This paper presents an adaptive architecture that allows centralized control of public lighting and intelligent management, in order to economise on lighting and maintain maximum comfort status of the illuminated areas. To carry out this management, architecture merges various techniques of artificial intelligence (AI) and statistics such as artificial neural networks (ANN), multi-agent systems (MAS), EM algorithm, methods based on ANOVA and a Service Oriented Aproach (SOA). It performs optim...

  10. OAJ control system

    Science.gov (United States)

    Antón, J. L.; Yanes-Díaz, A.; Rueda-Teruel, S.; Luis-Simoes, R.; Chueca, S.; Lasso-Cabrera, N. M.; Bello, R.; Jiménez, D.; Suárez, O.; Guillén, L.; López-Alegre, G.; Rodríguez, M. A.; de Castro, S.; Nevot, C.; Sánchez-Artigot, J.; Moles, M.; Cenarro, A. J.; Marín-Franch, A.; Ederoclite, A.; Varela, J.; Valdivielso, L.; Cristóbal-Hornillos, D.; López-Sainz, A.; Hernández-Fuertes, J.; Díaz-Martín, M. C.; Iglesias-Marzoa, R.; Abril, J.; Lamadrid, J. L.; Maicas, N.; Rodríguez, S.; Tilve, V.; Civera, T.; Muniesa, D. J.

    2015-05-01

    The Observatorio Astrofísico de Javalambre (OAJ) is a new astronomical facility located at the Sierra de Javalambre (Teruel, Spain) whose primary role will be to conduct all-sky astronomical surveys leveraging two unprecedented telescopes with unusually large fields of view: the JST/T250, a 2.55 m telescope with a 3 deg field of view, and the JAST/T80, an 83 cm telescope with a 2 deg field of view. The immediate objective of these telescopes for the next years is carrying out two unique photometric surveys covering several thousands square degrees: J-PAS and J-PLUS, each of them with a wide range of scientific applications, like e.g. large structure cosmology and Dark Energy, galaxy evolution, supernovae, Milky Way structure and exoplanets. JST and JAST will be equipped with panoramic cameras being developed within the J-PAS collaboration, JPCam and T80Cam respectively, which make use of large format (˜10{k}×10{k}) CCDs covering the entire focal plane. CEFCA engineering team has been designing the OAJ control system as a global concept to manage, monitor, control and service the observatory systems, not only astronomical but also infrastructure and other facilities. We will give an overview of OAJ's control system from an engineering point of view.

  11. Evaluation of mercury contamination in sediments from Santos - Sao Vicente Estuarine system, in period of 1996 -2000

    International Nuclear Information System (INIS)

    Hortellani, Marcos Antonio

    2003-01-01

    The distribution of mercury contamination in the Santos - Sao Vicente Estuarine System was observed through the analysis of seventy seven surface sediments samples collected in two series. In different periods and points, since the Channel of Piacaguera, the head of the system, , through the estuarine arms of Santos and Sao Vicente as far as the Bay of Santos, about 30 Km downstream, and in different mangrove areas, including industrial and harbor influence zones. The obtained values ranged from 0.03 to 1.19 μg g -1 About 90% of the samples of the first series collected among 1997-1998 and 50% of the second series collected among 1999-2000 presented levels of Hg > 0,13 μg g -1 ,limit considered by the Canadian legislation and adopted by CETESB, below which doesn't happen adverse effect in the biological community. And about 35% of samples of the first series and 11 % of the second series presented concentrations of Hg > 0.698 μg g -1 probable level of occurrence of adverse effect in the biological community. These results indicate an increase of the mercury levels caused by the industrial, port and urban activities. The mercury concentration in sediments was determined by using an Atomic Absorption Spectrophotometer, coupling with a flow injection system by a cold vapor generation, using a manual injection valve (FIA-CVAAS). The estimate of the uncertainties associated to this procedure was calculated. The following elements were also determined: Fe, Al, Zn, Ni, Pb, Cd, Cr and Co in 46 samples of the second series, by atomic absorption spectrometry. In order to verify possible relationship among all the investigated elements in the samples sediments, was carried out a statistical study, using the SPSS-8.0 software. Pearson correlation and Principal Component's analysis were used for with the objective to identify of major relationship for additional exploration of the general behavior of the data. (author)

  12. Health and environmental impact of mercury: Past and present experience

    Science.gov (United States)

    Rivera, A. T. F.; Cortes-Maramba, N. P.; Akagi, H.

    2003-05-01

    Mercury exists in various forms including metallic mercury, inorganie and organic mercury compounds. Research studies show that contamination brought about by natural and man-made activities is clearly a growing problem today. In 1956, the first recognized poisoning outbreaks occurred. Minamata Disease is a disorder of the central nervous system caused by the consumption of fish and shellfish contaminated with methylmercury. Clinical manifestation differs from inorganic mercury poisoning in which the kidneys and the renal system are damaged. The toxidrome consists of sensory disorders in the distal portion of the four extremities, cerebral ataxia, bilateral concentric constriction of the visual field. central disorder of ocular movement, central hearing impairment and disequilibrium. Fetal type Minamata Disease bom of mothers being exposed to methylmercury during pregnancy resulted in conditions similar to those associated with “infantile cerebral palsy" were also documented. Measures to control environmental pollution were implemented such as the environmental restoration project, compensation and relief of victims as part of the health and environmental management undertaken by the government. At present, global research studies are focusing on long-term and low-dose inorganic and methyl mercury exposure; and developmental neurobehavioral toxicity including relevant environmental factors influencing mercury transformations, mass balances and partitioning in ecosystems.

  13. NSLS control system upgrade

    International Nuclear Information System (INIS)

    Smith, J.D.; Ramamoorthy, S.; Tang, Yong N.

    1995-01-01

    The NSLS consists of two storage rings, a booster and a linac. A major upgrade of the control system (installed in 1978) was undertaken and has been completed. The computer architecture is being changed from a three level star-network to a two level distributed system. The microprocessor subsystem, host computer and workstations, communication link and the main software components are being upgraded or replaced. Since the NSLS rings operate twenty four hours a day a year with minimum maintenance time, the key requirement during the upgrade phase is a non-disruptive transition with minimum downtime. Concurrent with the upgrade, some immediate improvements were required. This paper describes the various components of the upgraded system and outlines the future plans

  14. NSLS control system upgrade

    International Nuclear Information System (INIS)

    Smith, J.D.; Ramamoorthy, Susila; Tang, Y.N.

    1994-01-01

    The NSLS consists of two storage rings, a booster and a linac. A major upgrade of the control system (installed in 1978) was undertaken and has been completed. The computer architecture is being changed from a three level star-network to a two level distributed system. The microprocessor subsystem, host computer and workstations, communication link and the main software components are being upgraded or replaced. Since the NSLS rings operate twenty four hours a day a year with minimum maintenance time, the key requirement during the upgrade phase is a non-disruptive transition with minimum downtime. Concurrent with the upgrade, some immediate improvements were required. This paper describes the various components of the upgraded system and outlines the future plans. ((orig.))

  15. NSLS control system upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J.D.; Ramamoorthy, S.; Tang, Yong N.

    1995-12-31

    The NSLS consists of two storage rings, a booster and a linac. A major upgrade of the control system (installed in 1978) was undertaken and has been completed. The computer architecture is being changed from a three level star-network to a two level distributed system. The microprocessor subsystem, host computer and workstations, communication link and the main software components are being upgraded or replaced. Since the NSLS rings operate twenty four hours a day a year with minimum maintenance time, the key requirement during the upgrade phase is a non-disruptive transition with minimum downtime. Concurrent with the upgrade, some immediate improvements were required. This paper describes the various components of the upgraded system and outlines the future plans.

  16. Mass-Dependent and -Independent Fractionation of Mercury Isotopes in Aquatic Systems

    Science.gov (United States)

    Bergquist, B. A.; Joel, B. D.; Jude, D. J.

    2008-12-01

    Mercury is a globally distributed and highly toxic pollutant. Although Hg is a proven health risk, much of the natural cycle of Hg is not well understood and new approaches are needed to track Hg and the chemical transformations it undergoes in the environment. Recently, we demonstrated that Hg isotopes exhibit two types of isotope fractionation: (1) mass dependent fractionation (MDF) and (2) mass independent fractionation (MIF) of only the odd isotopes (Bergquist and Blum, 2007). The observation of large MIF of Hg isotopes (up to 5 permil) is exciting because only a few other isotopic systems have been documented to display large MIF, the most notable of which are oxygen and sulfur. In both cases, the application of MIF has proven very useful in a variety of fields including cosmochemistry, paleoclimatology, physical chemistry, atmospheric chemistry, and biogeochemistry. Both MDF and MIF isotopic signatures are observed in natural samples, and together they open the door to a new method for tracing Hg pollution and for investigating Hg behavior in the environment. For example, fish record MDF that appears to be related to size and age. Additionally, fish display MIF signatures that are consistent with the photo-reduction of methylmercury (Bergquist and Blum, 2007). If the MDF and MIF in ecosystems can be understood, the signatures in fish could inform us about the sources and processes transforming Hg and why there are differences in the bioaccumulation of Hg in differing ecosystems and populations of fish. This requires sampling of a variety of ecosystems, the sampling of many components of the ecosystems, and the use of other tracers such as carbon and nitrogen isotopes. We have expanded our studies of aquatic ecosystems to include several lakes in North America. Similar to other isotopic systems used to study food web dynamics and structure (i.e., C and N), the MDF of Hg in fish appears to be related to size and age. The MDF recorded in fish likely reflects

  17. Radiation control system

    International Nuclear Information System (INIS)

    Murao, Mitsuo.

    1985-01-01

    Purpose: To rapidly and suitably performing planning and designation by radiation-working control systems in the radiation controlled area of nuclear power plant. Method: Various informations regarding radiation exposure are arranged and actual exposure data are statistically stored, to thereby perform forecasting calculation for the radiation exposure upon workings in the plurality of working regions in the radiation controlled area. Based on the forecast values and the registered workers' exposure dose in the past workings are alocated successively such that the total exposure does upon conducting the workings is less than the limited value, to prepare working plans in the areas. Further, procedures for preparing a series of documents regarding the workings in the radiation area are automated to rapidly and properly provide the informations serving to the planning and designation for the radiation workings. As a result, the radiation managers' burnden can be mitigated and an efficient working management system can be provided, in view of the exposure management and personal management. (Kamimura, M.)

  18. Crawling the Control System

    International Nuclear Information System (INIS)

    Larrieu, Theodore

    2009-01-01

    Information about accelerator operations and the control system resides in various formats in a variety of places on the lab network. There are operating procedures, technical notes, engineering drawings, and other formal controlled documents. There are programmer references and API documentation generated by tools such as doxygen and javadoc. There are the thousands of electronic records generated by and stored in databases and applications such as electronic logbooks, training materials, wikis, and bulletin boards and the contents of text-based configuration files and log files that can also be valuable sources of information. The obvious way to aggregate all these sources is to index them with a search engine that users can then query from a web browser. Toward this end, the Google 'mini' search appliance was selected and implemented because of its low cost and its simple web-based configuration and management. In addition to crawling and indexing electronic documents, the appliance provides an API that has been used to supplement search results with live control system data such as current values of EPICS process variables and graphs of recent data from the archiver.

  19. Role of bacteria in bioaccumulation of mercury in the oyster Crassostrea virginica

    International Nuclear Information System (INIS)

    Sayler, G.S.; Nelson, J.D. Jr.; Colwell, R.R.

    1975-01-01

    An investigation of mercury-resistant bacteria was undertaken to determine their role in the accumulation of mercury in a simplified food chain. Oysters (Crassostrea virginica) were maintained in a closed system, sealed aquarium with stirred, aerated water containing 10 μg of 203 HgCl 2 per liter. Uptake of 203 Hg by oysters held under control conditions was compared with that of 203 Hg uptake by oysters under similar conditions except that mercury-accumulating and mercury-metabolizing species of Pseudomonsa, isolated from Chesapeake Bay, were added to the experimental oysters. After incubation for 4 days, the major portion of the 203 Hg in the water column was found to be associated with the microparticulate fraction, corresponding to a rise in total viable count. Mercury accumulation in the oysters was significantly higher in the gill and fisceral tissue than other tissues. Mercury concentrations were 200 times greater in tissue fractions of oysters dosed with mercury-metabolizing bacteria compared with the oysters held under control conditions without mercury-metabolizing bacteria. (U.S.)

  20. Mercury content in the parasite-host system of Ligula intestinalis and Abramis brama and the effect of the parasite on fish muscle composition

    Directory of Open Access Journals (Sweden)

    Miroslava Palíková

    2014-01-01

    Full Text Available The bioaccumulation potential of parasites resulting from the competition for chemical elements including heavy metals represents a valuable instrument of evaluating the functions of the parasite-host system. In the present study, the effect of the parasite-host system of Ligula intestinalis and Abramis brama on the mercury concentrations and fish muscle composition of infected and non-infected fish was evaluated. Nine parasitized and seven non-parasitized fish were studied. The total mercury content in the samples was determined by the atomic-absorption spectrophotometry method. Standard indicators of the chemical composition of muscles (dry matter, crude protein, fats, and ash and a spectrum of fatty acids were evaluated. The mean mercury concentration in the biomass of plerocercoids was 0.045 ± 0.025 mg·kg-1; about × 7 lower compared to fish muscles. The mean mercury concentration in the muscles of infected and non-infected fish was 0.36 ± 0.11 and 0.24 ± 0.1, respectively. There was no difference in the composition of fish muscles and the spectrum of fatty acids. Ligula intestinalis takes nutrients from the fish body but according to the results of our study, the withdrawal of the monitored nutrients was uniform without any selection. Mercury is not efficiently accumulated by plerocercoids of Ligula intestinalis. This study brings novel data for this heavy metal and for this parasite host system.

  1. Incoherent control of locally controllable quantum systems

    International Nuclear Information System (INIS)

    Dong Daoyi; Zhang Chenbin; Rabitz, Herschel; Pechen, Alexander; Tarn, T.-J.

    2008-01-01

    An incoherent control scheme for state control of locally controllable quantum systems is proposed. This scheme includes three steps: (1) amplitude amplification of the initial state by a suitable unitary transformation, (2) projective measurement of the amplified state, and (3) final optimization by a unitary controlled transformation. The first step increases the amplitudes of some desired eigenstates and the corresponding probability of observing these eigenstates, the second step projects, with high probability, the amplified state into a desired eigenstate, and the last step steers this eigenstate into the target state. Within this scheme, two control algorithms are presented for two classes of quantum systems. As an example, the incoherent control scheme is applied to the control of a hydrogen atom by an external field. The results support the suggestion that projective measurements can serve as an effective control and local controllability information can be used to design control laws for quantum systems. Thus, this scheme establishes a subtle connection between control design and controllability analysis of quantum systems and provides an effective engineering approach in controlling quantum systems with partial controllability information.

  2. Control of optical systems

    Science.gov (United States)

    Founds, D.

    1988-01-01

    Some of the current and planned activities at the Air Force Systems Command in structures and controls for optical-type systems are summarized. Many of the activities are contracted to industry; one task is an in-house program which includes a hardware test program. The objective of the in-house program, referred to as the Aluminum Beam Expander Structure (ABES), is to address issues involved in on-orbit system identification. The structure, which appears similar to the LDR backup structure, is about 35 feet tall. The activity to date has been limited to acquisition of about 250 hours of test data. About 30 hours of data per excitation force is gathered in order to obtain sufficient data for a good statistical estimate of the structural parameters. The development of an Integrated Structural Modeling (ISM) computer program is being done by Boeing Aerospace Company. The objective of the contracted effort is to develop a combined optics, structures, thermal, controls, and multibody dynamics simulation code.

  3. Feedwater control system

    International Nuclear Information System (INIS)

    Cook, B.M.

    1982-01-01

    Excessive swing of the feedwater in nuclear reactor power supply apparatus on the occurrence of a transient is suppressed by injecting an anticipatory compensating signal (δWsub(fw)) into the control for the feedwater. Typical overshoot occurs on removal of a large part of the load, the steam flow is reduced so that the conventional control system reduces the flow of feedwater. At the same time there is a reduction of feedwater level in the steam generator because of the collapse of the bubbles under increased steam pressure. By the time the control responds to the drop in level, the apparatus has begun to stabilize so that there is overshoot. The anticipatory signal is derived from the boiling power (BP) which is a function of the nuclear power (Qsub(N)) developed, the enthalpy of saturated water (hsub(s)) and the enthalpy of the feedwater injected into the steam generator (hsub(fw)). From the boiling power (BP) and the increment in steam pressure resulting from the transient an anticipatory increment of feedwater flow is derived. This increment is added to the other parameters controlling the feedwater. (author)

  4. Phytoremediation of Ionic and Methyl Mercury Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Meagher, Richard B.

    2004-12-01

    Phytoremediation is defined as the use of plants to extract, resist, detoxify, and/or sequester toxic environmental pollutants. The long-term goal of the proposed research is to develop and test highly productive, field-adapted plant species that have been engineered for the phytoremediation of mercury. A variety of different genes, which should enable plants to clean mercury polluted sites are being tested as tools for mercury phytoremediation, first in model laboratory plants and then in potential field species. Several of these genes have already been shown to enhance mercury phytoremediation. Mercury pollution is a serious, world-wide problem affecting the health of human and wildlife populations. Environmentally, the most serious mercury threat is the production of methylmercury (CH3Hg+) by native bacteria at mercury contaminated wetland sites. Methylmercury is inherently more toxic than metallic (Hg(0)) or ionic (Hg(II)) mercury, and because methylmercury is prolifically biomagnified up the food chain, it poses the most immediate danger to animal populations. We have successfully engineered two model plants, Arabidopsis and tobacco, to use the bacterial merB gene to convert methylmercury to less toxic ionic mercury and to use the bacterial merA gene to further detoxify ionic mercury to the least toxic form of mercury, metallic mercury. Plants expressing both MerA and MerB proteins detoxify methylmercury in two steps to the metallic form. These plants germinate, grow, and set seed at normal growth rates on levels of methylmercury or ionic mercury that are lethal to normal plants. Our newest efforts involve engineering plants with several additional bacterial and plant genes that allow for higher levels of mercury resistance and mercury hyperaccumulation. The potential for these plants to hyperaccumulate mercury was further advanced by developing constitutive, aboveground, and root-specific gene expression systems.

  5. Adaptive control for chaotic systems

    Energy Technology Data Exchange (ETDEWEB)

    Hua Changchun E-mail: cch@ysu.edu.cn; Guan Xinping

    2004-10-01

    Control problem of chaotic system is investigated via adaptive method. A fairly simple adaptive controller is constructed, which can control chaotic systems to unstable fixed points. The precise mathematical models of chaotic systems need not be known and only the fixed points and the dimensions of chaotic systems are required to be known. Simulations on controlling different chaotic systems are investigated and the results show the validity and feasibility of the proposed controller.

  6. Unveiling Mercury's Mysteries with BepiColombo - an ESA/JAXA Mission to Explore the Innermost Planet of our Solar System

    Science.gov (United States)

    Benkhoff, J.

    2017-12-01

    NASA's MESSENGER mission has fundamentally changed our view of the innermost planet. Mercury is in many ways a very different planet from what we were expecting. Now BepiColombo has to follow up on answering the fundamental questions that MESSENGER raised and go beyond. BepiColombo is a joint project between the European Space Agency (ESA) and the Japanese Aerospace Exploration Agency (JAXA). The Mission consists of two orbiters, the Mercury Planetary Orbiter (MPO) and the Mercury Magnetospheric Orbiter (MMO). The mission scenario foresees a launch of both spacecraft with an ARIANE V in October 2018 and an arrival at Mercury in 2025. From their dedicated orbits the two spacecraft will be studying the planet and its environment. BepiColombo will study and understand the composition, geophysics, atmosphere, magnetosphere and history of Mercury, the least explored planet in the inner Solar System. In addition, the BepiColombo mission will provide a rare opportunity to collect multi-point measurements in a planetary environment. This will be particularly important at Mercury because of short temporal and spatial scales in the Mercury's environment. The foreseen orbits of the MPO and MMO will allow close encounters of the two spacecrafts throughout the mission. The MPO scientific payload comprises eleven instruments/instrument packages; The MMO comprises 5 instruments/instrument packages to the the study of the environment. The MPO will focus on a global characterization of Mercury through the investigation of its interior, surface, exosphere and magnetosphere. In addition, it will be testing Einstein's theory of general relativity. Together, the scientific payload of both spacecraft will provide the detailed information necessary to understand Mercury and its magnetospheric environment and to find clues to the origin and evolution of a planet close to its parent star. The BepiColombo mission will complement and follow up the work of NASA's MESSENGER mission by

  7. BLTC control system software

    Energy Technology Data Exchange (ETDEWEB)

    Logan, J.B., Fluor Daniel Hanford

    1997-02-10

    This is a direct revision to Rev. 0 of the BLTC Control System Software. The entire document is being revised and released as HNF-SD-FF-CSWD-025, Rev 1. The changes incorporated by this revision include addition of a feature to automate the sodium drain when removing assemblies from sodium wetted facilities. Other changes eliminate locked in alarms during cold operation and improve the function of the Oxygen Analyzer. See FCN-620498 for further details regarding these changes. Note the change in the document number prefix, in accordance with HNF-MD-003.

  8. PEP instrumentation and control system

    Energy Technology Data Exchange (ETDEWEB)

    Melen, R.

    1980-06-01

    This paper describes the operating characteristics of the primary components that form the PEP Instrumentation and Control System. Descriptions are provided for the computer control system, beam monitors, and other support systems.

  9. PEP instrumentation and control system

    International Nuclear Information System (INIS)

    Melen, R.

    1980-06-01

    This paper describes the operating characteristics of the primary components that form the PEP Instrumentation and Control System. Descriptions are provided for the computer control system, beam monitors, and other support systems

  10. Automatically controlled training systems

    International Nuclear Information System (INIS)

    Milashenko, A.; Afanasiev, A.

    1990-01-01

    This paper reports that the computer system for NPP personnel training was developed for training centers in the Soviet Union. The system should be considered as the first step in training, taking into account that further steps are to be devoted to part-task and full scope simulator training. The training room consists of 8-12 IBM PC/AT personal computers combined into a network. A trainee accesses the system in a dialor manner. Software enables the instructor to determine the trainee's progress in different subjects of the program. The quality of any trainee preparedness may be evaluated by Knowledge Control operation. Simplified dynamic models are adopted for separate areas of the program. For example, the system of neutron flux monitoring has a dedicated model. Currently, training, requalification and support of professional qualifications of nuclear power plant operators is being emphasized. A significant number of emergency situations during work are occurring due to operator errors. Based on data from September-October 1989, more than half of all unplanned drops in power and stoppages of power plants were due to operator error. As a comparison, problems due to equipment malfunction accounted for no more than a third of the total. The role of personnel, especially of the operators, is significant during normal operations, since energy production costs as well as losses are influenced by the capability of the staff. These facts all point to the importance of quality training of personnel

  11. A systems toxicology approach identifies Lyn as a key signaling phosphoprotein modulated by mercury in a B lymphocyte cell model

    Energy Technology Data Exchange (ETDEWEB)

    Caruso, Joseph A.; Stemmer, Paul M. [Institute of Environmental Health Sciences, Wayne State University, Detroit, MI (United States); Dombkowski, Alan [Department of Pediatrics, Wayne State University, Detroit, MI (United States); Caruthers, Nicholas J. [Institute of Environmental Health Sciences, Wayne State University, Detroit, MI (United States); Gill, Randall [Department of Immunology and Microbiology, Wayne State University, Detroit, MI (United States); Rosenspire, Allen J., E-mail: arosenspire@wayne.edu [Department of Immunology and Microbiology, Wayne State University, Detroit, MI (United States)

    2014-04-01

    Network and protein–protein interaction analyses of proteins undergoing Hg{sup 2+}-induced phosphorylation and dephosphorylation in Hg{sup 2+}-intoxicated mouse WEHI-231 B cells identified Lyn as the most interconnected node. Lyn is a Src family protein tyrosine kinase known to be intimately involved in the B cell receptor (BCR) signaling pathway. Under normal signaling conditions the tyrosine kinase activity of Lyn is controlled by phosphorylation, primarily of two well known canonical regulatory tyrosine sites, Y-397 and Y-508. However, Lyn has several tyrosine residues that have not yet been determined to play a major role under normal signaling conditions, but are potentially important sites for phosphorylation following mercury exposure. In order to determine how Hg{sup 2+} exposure modulates the phosphorylation of additional residues in Lyn, a targeted MS assay was developed. Initial mass spectrometric surveys of purified Lyn identified 7 phosphorylated tyrosine residues. A quantitative assay was developed from these results using the multiple reaction monitoring (MRM) strategy. WEHI-231 cells were treated with Hg{sup 2+}, pervanadate (a phosphatase inhibitor), or anti-Ig antibody (to stimulate the BCR). Results from these studies showed that the phosphoproteomic profile of Lyn after exposure of the WEHI-231 cells to a low concentration of Hg{sup 2+} closely resembled that of anti-Ig antibody stimulation, whereas exposure to higher concentrations of Hg{sup 2+} led to increases in the phosphorylation of Y-193/Y-194, Y-501 and Y-508 residues. These data indicate that mercury can disrupt a key regulatory signal transduction pathway in B cells and point to phospho-Lyn as a potential biomarker for mercury exposure. - Highlights: • Inorganic mercury (Hg{sup 2+}) induces changes in the WEHI-231 B cell phosphoproteome. • The B cell receptor (BCR) signaling pathway was the pathway most affected by Hg{sup 2+}. • The Src family phosphoprotein kinase Lyn was the

  12. MODELING THE IMPACT OF ELEVATED MERCURY IN DEFENSE WASTE PROCESSING FACILITY MELTER FEED ON THE MELTER OFF-GAS SYSTEM-PRELIMINARY REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Zamecnik, J.; Choi, A.

    2010-08-18

    The Defense Waste Processing Facility (DWPF) is currently evaluating an alternative Chemical Process Cell (CPC) flowsheet to increase throughput. It includes removal of the steam-stripping step, which would significantly reduce the CPC processing time and lessen the sampling needs. However, its downside would be to send 100% of the mercury that comes in with the sludge straight to the melter. For example, the new mercury content in the Sludge Batch 5 (SB5) melter feed is projected to be 25 times higher than that in the SB4 with nominal steam stripping of mercury. This task was initiated to study the impact of the worst-case scenario of zero-mercury-removal in the CPC on the DWPF melter offgas system. It is stressed that this study is intended to be scoping in nature, so the results presented in this report are preliminary. In order to study the impact of elevated mercury levels in the feed, it is necessary to be able to predict how mercury would speciate in the melter exhaust under varying melter operating conditions. A homogeneous gas-phase oxidation model of mercury by chloride was developed to do just that. The model contains two critical parameters pertaining to the partitioning of chloride among HCl, Cl, Cl{sub 2}, and chloride salts in the melter vapor space. The values for these parameters were determined at two different melter vapor space temperatures by matching the calculated molar ratio of HgCl (or Hg{sub 2}Cl{sub 2}) to HgCl{sub 2} with those measured during the Experimental-Scale Ceramic Melter (ESCM) tests run at the Pacific Northwest National Laboratory (PNNL). The calibrated model was then applied to the SB5 simulant used in the earlier flowsheet study with an assumed mercury stripping efficiency of zero; the molar ratio of Cl-to-Hg in the resulting melter feed was only 0.4, compared to 12 for the ESCM feeds. The results of the model run at the indicated melter vapor space temperature of 650 C (TI4085D) showed that due to excessive shortage of

  13. Modeling The Impact Of Elevated Mercury In Defense Waste Processing Facility Melter Feed On The Melter Off-Gas System - Preliminary Report

    International Nuclear Information System (INIS)

    Zamecnik, J.; Choi, A.

    2009-01-01

    The Defense Waste Processing Facility (DWPF) is currently evaluating an alternative Chemical Process Cell (CPC) flowsheet to increase throughput. It includes removal of the steam-stripping step, which would significantly reduce the CPC processing time and lessen the sampling needs. However, its downside would be to send 100% of the mercury that come in with the sludge straight to the melter. For example, the new mercury content in the Sludge Batch 5 (SB5) melter feed is projected to be 25 times higher than that in the SB4 with nominal steam stripping of mercury. This task was initiated to study the impact of the worst-case scenario of zero-mercury-removal in the CPC on the DWPF melter off-gas system. It is stressed that this study is intended to be scoping in nature, so the results presented in this report are preliminary. In order to study the impact of elevated mercury levels in the feed, it is necessary to be able to predict how mercury would speciate in the melter exhaust under varying melter operating conditions. A homogeneous gas-phase oxidation model of mercury by chloride was developed to do just that. The model contains two critical parameters pertaining to the partitioning of chloride among HCl, Cl, Cl 2 , and chloride salts in the melter vapor space. The values for these parameters were determined at two different melter vapor space temperatures by matching the calculated molar ratio of HgCl (or Hg 2 Cl 2 ) to HgCl 2 with those measured during the Experimental-Scale Ceramic Melter (ESCM) tests run at the Pacific Northwest National Laboratory (PNNL). The calibrated model was then applied to the SB5 simulant used in the earlier flowsheet study with an assumed mercury stripping efficiency of zero; the molar ratio of Cl-to-Hg in the resulting melter feed was only 0.4, compared to 12 for the ESCM feeds. The results of the model run at the indicated melter vapor space temperature of 650 C (TI4085D) showed that due to excessive shortage of chloride, only 6% of

  14. Mercury heavy-metal-induced physiochemical changes and genotoxic alterations in water hyacinths [Eichhornia crassipes (Mart.)].

    Science.gov (United States)

    Malar, Srinivasan; Sahi, Shivendra Vikram; Favas, Paulo J C; Venkatachalam, Perumal

    2015-03-01

    Mercury heavy metal pollution has become an important environmental problem worldwide. Accumulation of mercury ions by plants may disrupt many cellular functions and block normal growth and development. To assess mercury heavy metal toxicity, we performed an experiment focusing on the responses of Eichhornia crassipes to mercury-induced oxidative stress. E. crassipes seedlings were exposed to varying concentrations of mercury to investigate the level of mercury ions accumulation, changes in growth patterns, antioxidant defense mechanisms, and DNA damage under hydroponics system. Results showed that plant growth rate was significantly inhibited (52 %) at 50 mg/L treatment. Accumulation of mercury ion level were 1.99 mg/g dry weight, 1.74 mg/g dry weight, and 1.39 mg/g dry weight in root, leaf, and petiole tissues, respectively. There was a decreasing trend for chlorophyll a, b, and carotenoids with increasing the concentration of mercury ions. Both the ascorbate peroxidase and malondialdehyde contents showed increased trend in leaves and roots up to 30 mg/L mercury treatment and slightly decreased at the higher concentrations. There was a positive correlation between heavy metal dose and superoxide dismutase, catalase, and peroxidase antioxidative enzyme activities which could be used as biomarkers to monitor pollution in E. crassipes. Due to heavy metal stress, some of the normal DNA bands were disappeared and additional bands were amplified compared to the control in the random amplified polymorphic DNA (RAPD) profile. Random amplified polymorphic DNA results indicated that genomic template stability was significantly affected by mercury heavy metal treatment. We concluded that DNA changes determined by random amplified polymorphic DNA assay evolved a useful molecular marker for detection of genotoxic effects of mercury heavy metal contamination in plant species.

  15. Mercury emissions from municipal solid waste combustors

    Energy Technology Data Exchange (ETDEWEB)

    1993-05-01

    This report examines emissions of mercury (Hg) from municipal solid waste (MSW) combustion in the United States (US). It is projected that total annual nationwide MSW combustor emissions of mercury could decrease from about 97 tonnes (1989 baseline uncontrolled emissions) to less than about 4 tonnes in the year 2000. This represents approximately a 95 percent reduction in the amount of mercury emitted from combusted MSW compared to the 1989 mercury emissions baseline. The likelihood that routinely achievable mercury emissions removal efficiencies of about 80 percent or more can be assured; it is estimated that MSW combustors in the US could prove to be a comparatively minor source of mercury emissions after about 1995. This forecast assumes that diligent measures to control mercury emissions, such as via use of supplemental control technologies (e.g., carbon adsorption), are generally employed at that time. However, no present consensus was found that such emissions control measures can be implemented industry-wide in the US within this time frame. Although the availability of technology is apparently not a limiting factor, practical implementation of necessary control technology may be limited by administrative constraints and other considerations (e.g., planning, budgeting, regulatory compliance requirements, etc.). These projections assume that: (a) about 80 percent mercury emissions reduction control efficiency is achieved with air pollution control equipment likely to be employed by that time; (b) most cylinder-shaped mercury-zinc (CSMZ) batteries used in hospital applications can be prevented from being disposed into the MSW stream or are replaced with alternative batteries that do not contain mercury; and (c) either the amount of mercury used in fluorescent lamps is decreased to an industry-wide average of about 27 milligrams of mercury per lamp or extensive diversion from the MSW stream of fluorescent lamps that contain mercury is accomplished.

  16. Mercury concentrations at a historically mercury-contaminated site in KwaZulu-Natal, South Africa

    CSIR Research Space (South Africa)

    Williams, CR

    2011-02-01

    Full Text Available . Biogeochem., 43:237?257 Barrat GJ, Combrink J (2002) An Assessment of the degree of mercury (Hg) bio-transformation in two river systems following discharges from a mercury recovery plant. Water SA Special Edition: WISA Proceedings 2002 Benoit JM... in mercury and methylmercury biogeochemical cycling and bioaccumulation within shallow estuaries. PhD thesis, University of Maryland, College Park Kim E-H, Mason RP, Porter ET, Soulen HL (2006) The impact of resuspension on sediment mercury dynamics...

  17. Fate and transport of mercury in soil systems : a numerical model in HP1 and sensitivity analysis

    Science.gov (United States)

    Leterme, Bertrand; Jacques, Diederik

    2013-04-01

    Mercury (Hg) poses threats for human health and the environment, notably due to its persistence and its ability to bioaccumulate in ecosystems. Anthropogenic activities are major contributors of mercury release to soils. Main sources of contamination include manufacturing (chlor-alkali plants, manometer spill), mine tailings from mercury, gold and silver mining industries, wood preservation. The objective of this study was to develop a reactive transport model for simulating mercury fate and transport in the unsaturated zone, and to gain insight in the fate and transport of Hg following anthropogenic soil contamination. The present work is done in the framework of the IMaHg project, which aims at providing recommendations to improve management of sites contaminated by mercury within the SNOWMAN funding framework. A model of mercury fate and transport in soil systems was developed using the reactive transport code HP1 (Jacques and Šimůnek, 2010). The geochemical database THERMODDEM (Blanc et al., 2012) is used, augmented with some speciation data from (Skyllberg, 2012). The main processes accounted for in the model are : Hg aqueous speciation (including complexation with dissolved organic matter (DOM) - humic and fulvic acids, and thiol groups), Hg sorption to solid organic matter (SOM), dissolution of solid phase Hg (e.g. cinnabar HgS(s)), dissolution of Hg non-aqueous liquid phase (NAPL), sunlight-driven Hg(II) reduction to Hg(0), Hg(0) diffusion in the gas phase and volatilization, DOM sorption to soil minerals. Colloid facilitated transport is implicitly accounted for by solute transport of Hg-DOM complexes. Because we focused on soil systems having a high Hg contamination, some processes showing relatively smaller Hg fluxes could be neglected such as vegetation uptake and atmospheric wet and dry deposition. NAPL migration and entrapment is not modelled, as pollution is assumed to be historical and only residual NAPL to be present. Mercury methylation and

  18. A synthesis of rates and controls on elemental mercury evasion in the Great Lakes Basin

    International Nuclear Information System (INIS)

    Denkenberger, Joseph S.; Driscoll, Charles T.; Branfireun, Brian A.; Eckley, Chris S.; Cohen, Mark; Selvendiran, Pranesh

    2012-01-01

    Rates of surface-air elemental mercury (Hg 0 ) fluxes in the literature were synthesized for the Great Lakes Basin (GLB). For the majority of surfaces, fluxes were net positive (evasion). Digital land-cover data were combined with representative evasion rates and used to estimate annual Hg 0 evasion for the GLB (7.7 Mg/yr). This value is less than our estimate of total Hg deposition to the area (15.9 Mg/yr), suggesting the GLB is a net sink for atmospheric Hg. The greatest contributors to annual evasion for the basin are agricultural (∼55%) and forest (∼25%) land cover types, and the open water of the Great Lakes (∼15%). Areal evasion rates were similar across most land cover types (range: 7.0–21.0 μg/m 2 -yr), with higher rates associated with urban (12.6 μg/m 2 -yr) and agricultural (21.0 μg/m 2 -yr) lands. Uncertainty in these estimates could be partially remedied through a unified methodological approach to estimating Hg 0 fluxes. - Highlights: ► Considerable variability exists across spatial/temporal scales in Hg 0 evasion rates. ► Methodological approaches vary for estimating and reporting gaseous Hg 0 fluxes. ► Hg 0 evasion from the Great Lakes Basin is estimated at 7.7 Mg/yr (10.2 μg/m 2 -yr). ► Hg flux estimates suggest region is a net sink for atmospheric Hg. ► 95% of Hg 0 evasion in the region is from agriculture, forest, and the Great Lakes. - A synthesis of Hg evasion was conducted and this information was used to develop an estimate of Hg evasion for the Great Lakes Basin.

  19. Controlling Factors of Mercury Wet Deposition and Precipitation Concentrations in Upstate New York

    Science.gov (United States)

    Ye, Z.; Mao, H.; Driscoll, C. T.

    2017-12-01

    Observations from the Mercury Deposition Network (MDN) at Huntington Wildlife Forest (HWF) suggested that a significant decline in Hg concentrations in precipitation was linked to Hg emission decreases in the United States, especially in the Northeast and Midwest, and yet Hg wet deposition has remained fairly constant over the past two decades. The present study was aimed to investigate how climatic, terrestrial, and anthropogenic factors had influenced the Hg wet deposition flux in upstate New York (NY). To achieve this, an improved Community Multiscale Air Quality (CMAQ) model was employed, which included state-of-the-art Hg and halogen chemistry mechanisms. A base simulation and five sensitivity simulations were conducted. The base simulation used 2010 meteorology, U.S. EPA NEI 2011, and GEOS-Chem output as initial and boundary conditions (ICs and BCs). The five sensitivity runs each changed one condition at the time as follows: 1-3) 2004, 2005, and 2007 meteorology instead of 2010, 4) NEI 2005 Hg anthropogenic emission out of NYS instead of NEI 2011, and 5) no in-state Hg anthropogenic emission. The study period of all the simulations was March - November 2010, and the domain covered the northeastern United States at 12 km resolution. As a result, compared with rural areas in NYS, Hg wet deposition and ambient Hg concentrations in urban areas were affected more significantly by in-state anthropogenic Hg emission. The in-state anthropogenic Hg emissions contributed up to 20% of Hg wet deposition at urban sites and conditions, causing changes varying from a 91% decrease to a factor of 5 increase in monthly accumulated wet deposition amounts. Possible affecting meteorological factors included, not limited to, solar radiation, cloud height, precipitation, wind speed and direction, and relative humidity, among which precipitation had the largest effects in most areas. Diluting effects were found in non-convective precipitation, which contributed 31-48% to changes in

  20. Chemical form matters: differential accumulation of mercury following inorganic and organic mercury exposures in zebrafish larvae.

    Science.gov (United States)

    Korbas, Malgorzata; Macdonald, Tracy C; Pickering, Ingrid J; George, Graham N; Krone, Patrick H

    2012-02-17

    Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versusl-cysteine). For inorganic mercury species, in absence of l-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with l-cysteine present in the treatment solution, mercuric bis-l-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

  1. Chemical Form Matters: Differential Accumulation of Mercury Following Inorganic and Organic Mercury Exposures in Zebrafish Larvae

    Energy Technology Data Exchange (ETDEWEB)

    Korbas, Malgorzata; MacDonald, Tracy C.; Pickering, Ingrid J.; George, Graham N.; Krone, Patrick H. (Saskatchewan)

    2013-04-08

    Mercury, one of the most toxic elements, exists in various chemical forms each with different toxicities and health implications. Some methylated mercury forms, one of which exists in fish and other seafood products, pose a potential threat, especially during embryonic and early postnatal development. Despite global concerns, little is known about the mechanisms underlying transport and toxicity of different mercury species. To investigate the impact of different mercury chemical forms on vertebrate development, we have successfully combined the zebrafish, a well-established developmental biology model system, with synchrotron-based X-ray fluorescence imaging. Our work revealed substantial differences in tissue-specific accumulation patterns of mercury in zebrafish larvae exposed to four different mercury formulations in water. Methylmercury species not only resulted in overall higher mercury burdens but also targeted different cells and tissues than their inorganic counterparts, thus revealing a significant role of speciation in cellular and molecular targeting and mercury sequestration. For methylmercury species, the highest mercury concentrations were in the eye lens epithelial cells, independent of the formulation ligand (chloride versus L-cysteine). For inorganic mercury species, in absence of L-cysteine, the olfactory epithelium and kidney accumulated the greatest amounts of mercury. However, with L-cysteine present in the treatment solution, mercuric bis-L-cysteineate species dominated the treatment, significantly decreasing uptake. Our results clearly demonstrate that the common differentiation between organic and inorganic mercury is not sufficient to determine the toxicity of various mercury species.

  2. Field Testing of a Wet FGD Additive for Enhanced Mercury Control - Task 5 Full-Scale Test Results

    Energy Technology Data Exchange (ETDEWEB)

    Gary Blythe; MariJon Owens

    2007-12-01

    This Topical Report summarizes progress on Cooperative Agreement DE-FC26-04NT42309, 'Field Testing of a Wet FGD Additive'. The objective of the project is to demonstrate the use of two flue gas desulfurization (FGD) additives, Evonik Degussa Corporation's TMT-15 and Nalco Company's Nalco 8034, to prevent the re-emission of elemental mercury (Hg{sup 0}) in flue gas exiting wet FGD systems on coal-fired boilers. Furthermore, the project intends to demonstrate whether the additive can be used to precipitate most of the mercury (Hg) removed in the wet FGD system as a fine salt that can be separated from the FGD liquor and bulk solid byproducts for separate disposal. The project is conducting pilot- and full-scale tests of the additives in wet FGD absorbers. The tests are intended to determine required additive dosages to prevent Hg{sup 0} re-emissions and to separate mercury from the normal FGD byproducts for three coal types: Texas lignite/Powder River Basin (PRB) coal blend, high-sulfur Eastern bituminous coal, and low-sulfur Eastern bituminous coal. The project team consists of URS Group, Inc., EPRI, Luminant Power (was TXU Generation Company LP), Southern Company, IPL (an AES company), Evonik Degussa Corporation and the Nalco Company. Luminant Power has provided the Texas lignite/PRB co-fired test site for pilot FGD tests and cost sharing. Southern Company has provided the low-sulfur Eastern bituminous coal host site for wet scrubbing tests, as well as the pilot- and full-scale jet bubbling reactor (JBR) FGD systems tested. IPL provided the high-sulfur Eastern bituminous coal full-scale FGD test site and cost sharing. Evonik Degussa Corporation is providing the TMT-15 additive, and the Nalco Company is providing the Nalco 8034 additive. Both companies are also supplying technical support to the test program as in-kind cost sharing. The project is being conducted in six tasks. Of the six project tasks, Task 1 involves project planning and Task 6

  3. The influence of some thiols on biliary excretion of methyl mercury

    International Nuclear Information System (INIS)

    Refsvik, T.

    1983-01-01

    N-Acetylpenicillamine and thiola increased biliary excretion of methyl mercury and sulfhydryl right after administration. Cysteine increased excretion of methyl mercury in bile after a temporary decrease following administration. During the interval of decreased mercury excretion biliary excretion of cysteine passed through a maximum. This indicates the existence of a common factor of the excretory systems for cysteine and methyl mercury and illustrates that cysteine cannot carry methyl mercury from liver to bile. Relatively large proportions of unchanged thiola and N-acetylpenicillamine were excreted in bile. Bile collected after administration of one of these compounds, in addition to thiola or N-acetylpenicillamine, contained other methyl mercury carrying components not present in control bile. From the experiments undertaken it cannot be stated whether these components play any role in the increased excretion of methyl mercury in bile caused by thiola and N-acetylpenicillamine. The mechanisms of increased biliary excretion of methyl mercury following administration of N-acetylpenicillamine, thiola and cysteine are discussed. (author)

  4. A novel high efficiency fine particulate and mercury control device. Final report for the Department of Energy Contract Number DE-FG02-95ER81968

    Energy Technology Data Exchange (ETDEWEB)

    None

    1999-05-05

    This Phase II SBIR program was conducted to demonstrate the ability of a circulating fluidized bed (CFB) of flyash to cause particle agglomeration and consequent reduction in the quantity of fine particulate emissions from the system. Another objective was to show that carbon addition to the bed would result in the removal of mercury compounds from the flue gas at carbon utilization levels significantly better than duct injection of activated carbon. The pilot-scale testing was carried out in 1997. The pilot-scale fluid bed reactor was a 1000 CFM system, drawing gas from a slipstream of the exhaust of a 325 MW coal-fired boiler. Flue gas for the pilot unit was drawn downstream of the air preheater and returned to the same unit. Particle agglomeration testing was carried out for which the parameters of gas flow rate and water evaporation rate were varied, and the particle size distribution leaving the fluid bed system was monitored. The bed was able to cause a reduction in total particulate concentration by a factor of 10 and in fine particulate concentration by a factor of 5, and it was found that the best agglomeration of particles was obtained with simultaneous water spray evaporation. Tests were then carried out in which activated carbon was added to the fluid bed for mercury adsorption. Carbon addition in the bed was shown to yield both higher Hg removal and higher carbon utilization than normal carbon addition with the bed. The fluid bed fly ash alone, without the injection of activated carbon, will capture 50% of the inlet Hg vapor. A total of 80% removal of Hg vapor is achieved with the addition to the bed of 1000 g iodine impregnated activated carbon per gram of inlet Hg. The ability of the fluid bed to capture SO{sub 2} and HCl was also evaluated, using hydrated lime added to the bed. It was found that the fluid bed alone, without lime injection, removed 16% of the SO{sub 2}. Complete utilization of hydrated lime is achieved for SO{sub 2} removal at mole

  5. The transport behaviour of elemental mercury DNAPL in saturated porous media: analysis of field observations and two-phase flow modelling.

    Science.gov (United States)

    Sweijen, Thomas; Hartog, Niels; Marsman, Annemieke; Keijzer, Thomas J S

    2014-06-01

    Mercury is a contaminant of global concern. The use of elemental mercury in various (former) industrial processes, such as chlorine production at chlor-alkali plants, is known to have resulted in soil and groundwater contaminations worldwide. However, the subsurface transport behaviour of elemental mercury as an immiscible dense non-aqueous phase liquid (DNAPL) in porous media has received minimal attention to date. Even though, such insight would aid in the remediation effort of mercury contaminated sites. Therefore, in this study a detailed field characterization of elemental mercury DNAPL distribution with depth was performed together with two-phase flow modelling, using STOMP. This is to evaluate the dynamics of mercury DNAPL migration and the controls on its distribution in saturated porous media. Using a CPT-probe mounted with a digital camera, in-situ mercury DNAPL depth distribution was obtained at a former chlor-alkali-plant, down to 9 m below ground surface. Images revealing the presence of silvery mercury DNAPL droplets were used to quantify its distribution, characteristics and saturation, using an image analysis method. These field-observations with depth were compared with results from a one-dimensional two-phase flow model simulation for the same transect. Considering the limitations of this approach, simulations reasonably reflected the variability and range of the mercury DNAPL distribution. To further explore the impact of mercury's physical properties in comparison with more common DNAPLs, the migration of mercury and PCE DNAPL in several typical hydrological scenarios was simulated. Comparison of the simulations suggest that mercury's higher density is the overall controlling factor in controlling its penetration in saturated porous media, despite its higher resistance to flow due to its higher viscosity. Based on these results the hazard of spilled mercury DNAPL to cause deep contamination of groundwater systems seems larger than for any other

  6. Environmental controls on the speciation and distribution of mercury in surface sediments of a tropical estuary, India

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Babu, P.V.R.

    Distribution and speciation of mercury (Hg) in the sediments from a tropical estuary (Godavari estuary) was influenced by the changing physico-chemical parameters of the overlying water column. The sediments from the upstream and downstream...

  7. Fly Ash and Mercury Oxidation/Chlorination Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Sukh Sidhu; Patanjali Varanasi

    2008-12-31

    Mercury is a known pollutant that has detrimental effect on human health and environment. The anthropogenic emissions of mercury account for 10 to 30% of worldwide mercury emissions. There is a need to control/reduce anthropogenic mercury emissions. Many mercury control technologies are available but their effectiveness is dependent on the chemical form of mercury, because different chemical forms of mercury have different physical and chemical properties. Mercury leaves the boiler in its elemental form but goes through various transformations in the post-combustion zone. There is a need to understand how fly ash and flue gas composition affect speciation, partitioning, and reactions of mercury under the full range of post-combustion zone conditions. This knowledge can then be used to predict the chemical transformation of mercury (elemental, oxidized or particulate) in the post combustion zone and thus help with the control of mercury emissions from coal-burning power plants. To accomplish this goal present study was conducted using five coal fly ashes. These ashes were characterized and their catalytic activity was compared under selected reaction conditions in a fixed bed reactor. Based on the results from these fly ash experiments, three key components (carbon, iron oxide and calcium oxide) were chosen. These three components were then used to prepare model fly ashes. Silica/alumina was used as a base for these model fly ashes. One, two or three component model fly ashes were then prepared to investigate mercury transformation reactions. The third set of experiments was performed with CuO and CuCl2 catalysts to further understand the mercury oxidation process. Based on the results of these three studies the key components were predicted for different fly ash compositions under variety of flue gas conditions. A fixed bed reactor system was used to conduct this study. In all the experiments, the inlet concentration of Hg0(g) was maintained at 35 {micro}g/m3 using

  8. Coordination control of distributed systems

    CERN Document Server

    Villa, Tiziano

    2015-01-01

    This book describes how control of distributed systems can be advanced by an integration of control, communication, and computation. The global control objectives are met by judicious combinations of local and nonlocal observations taking advantage of various forms of communication exchanges between distributed controllers. Control architectures are considered according to  increasing degrees of cooperation of local controllers:  fully distributed or decentralized controlcontrol with communication between controllers,  coordination control, and multilevel control.  The book covers also topics bridging computer science, communication, and control, like communication for control of networks, average consensus for distributed systems, and modeling and verification of discrete and of hybrid systems. Examples and case studies are introduced in the first part of the text and developed throughout the book. They include: control of underwater vehicles, automated-guided vehicles on a container terminal, contro...

  9. PATHOLOIGCAL EFFECTS OF DIETARY METHYL MERCURY IN AMERICAN KESTRELS ( FALCO SPARVERIUS)

    Science.gov (United States)

    Methyl mercury in aquatic food webs poses significant health risks to both wildlife and humans. One primary source of mercury contamination for both aquatic and terrestrial systems is atmospheric deposition of inorganic mercury from industrial emissions. Once in the environment, ...

  10. Generic device controller for accelerator control systems

    International Nuclear Information System (INIS)

    Mariotti, R.; Buxton, W.; Frankel, R.; Hoff, L.

    1987-01-01

    A new distributed intelligence control system has become operational at the AGS for transport, injection, and acceleration of heavy ions. A brief description of the functionality of the physical devices making up the system is given. An attempt has been made to integrate the devices for accelerator specific interfacing into a standard microprocessor system, namely, the Universal Device Controller (UDC). The main goals for such a generic device controller are to provide: local computing power; flexibility to configure; and real time event handling. The UDC assemblies and software are described

  11. Shaded Spacecraft Radiators to Be Used on the Daytime Surface of the Mercury Planet, the Moon, and Asteroids of the Solar System Inner Part

    Directory of Open Access Journals (Sweden)

    V. A. Igrickii

    2016-01-01

    Full Text Available During the daytime a surface of the Moon, Mercury planet, and asteroids of the Solar system inner part, significantly heats up, and infrared radiation of the local soil becomes essential. At the same time direct solar radiation and reflected from the surface solar radiation reach the maximum too. These radiation fluxes can significantly decrease the efficiency of spacecraft radiators in the daytime. This effect is especially strong on the Mercury surface where direct solar radiation is 10 times stronger than solar radiation near the Earth. As a result, on the daytime surface of the Mercury the conventional low-temperature radiators become completely disabled.The article describes the development of the special shaded spacecraft radiators to be used in daytime on the Mercury and other atmosphereless bodies of the Solar system inner part. To solve this task are used mirror shades. The shape of these shades is developed to improve operation conditions of the spacecraft radiator through the appropriate scheme of radiation reflection. The task is discussed in 2D and 3D cases. A new design of shaded spacecraft radiators is proposed, and reasonable proportions of radiators are determined. The performance capability of proposed radiators for environments of the Mercury and the Moon is estimated using the zonal method in view of partial mirror reflection. The calculations showed that the developed shaded spacecraft radiators are capable to work on the Mercury surface as the low-temperature radiators even during the daytime. New radiators provide minimum accepted operating temperature of 241К (-32°С, meanwhile radiators of common design have minimum operating temperature of 479К (206°С. Using such radiators on the Moon enables us to increase effectiveness of spacecraft radiators and to decrease their minimum operating temperature from 270К (-3°С to 137К (-136°С.

  12. Networked control of microgrid system of systems

    Science.gov (United States)

    Mahmoud, Magdi S.; Rahman, Mohamed Saif Ur; AL-Sunni, Fouad M.

    2016-08-01

    The microgrid has made its mark in distributed generation and has attracted widespread research. However, microgrid is a complex system which needs to be viewed from an intelligent system of systems perspective. In this paper, a network control system of systems is designed for the islanded microgrid system consisting of three distributed generation units as three subsystems supplying a load. The controller stabilises the microgrid system in the presence of communication infractions such as packet dropouts and delays. Simulation results are included to elucidate the effectiveness of the proposed control strategy.

  13. Characterization of gradient control systems

    NARCIS (Netherlands)

    Cortés, Jorge; van der Schaft, Arjan; Crouch, Peter E.

    2005-01-01

    Given a general nonlinear affine control system with outputs and a torsion-free affine connection defined on its state space, we investigate the gradient realization problem: we give necessary and sufficient conditions under which the control system can be written as a gradient control system

  14. Mercury's Messenger

    Science.gov (United States)

    Chapman, Clark R.

    2004-01-01

    Forty years after Mariner 2, planetary exploration has still only just begun, and many more missions are on drawing boards, nearing the launch pad, or even en route across interplanetary space to their targets. One of the most challenging missions that will be conducted this decade is sending the MESSENGER spacecraft to orbit the planet Mercury.…

  15. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Joseph Rovani; Mark Sanderson

    2008-02-29

    Mercury continuous emissions monitoring systems (CEMS) are being implemented in over 800 coal-fired power plant stacks. The power industry desires to conduct at least a full year of monitoring before the formal monitoring and reporting requirement begins on January 1, 2009. It is important for the industry to have available reliable, turnkey equipment from CEM vendors. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The generators are used to calibrate mercury CEMs at power plant sites. The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005 requires that calibration be performed with NIST-traceable standards (Federal Register 2007). Traceability procedures will be defined by EPA. An initial draft traceability protocol was issued by EPA in May 2007 for comment. In August 2007, EPA issued an interim traceability protocol for elemental mercury generators (EPA 2007). The protocol is based on the actual analysis of the output of each calibration unit at several concentration levels ranging initially from about 2-40 {micro}g/m{sup 3} elemental mercury, and in the future down to 0.2 {micro}g/m{sup 3}, and this analysis will be directly traceable to analyses by NIST. The document is divided into two separate sections. The first deals with the qualification of generators by the vendors for use in mercury CEM calibration. The second describes the procedure that the vendors must use to certify the generator models that meet the qualification specifications. The NIST traceable certification is performance based, traceable to analysis using isotope dilution inductively coupled plasma/mass spectrometry performed by NIST in Gaithersburg, MD. The

  16. MERCURY REMOVAL IN A NON-THERMAL, PLASMA-BASED MULTI-POLLUTANT CONTROL TECHNOLOGY FOR UTILITY BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    Christopher R. McLaron

    2004-12-01

    Powerspan has conducted pilot scale testing of a multi-pollutant control technology at FirstEnergy's Burger Power Plant under a cooperative agreement with the U.S. Department of Energy. The technology, Electro-Catalytic Oxidation (ECO), simultaneously removes sulfur dioxide (SO{sub 2}), nitrogen oxides (NO{sub x}), fine particulate matter (PM{sub 2.5}) and mercury (Hg) from the flue gas of coal-fired power plants. Powerspan's ECO{reg_sign} pilot test program focused on optimization of Hg removal in a 1-MWe slipstream pilot while maintaining greater than 90% removal of NO{sub x} and 98% removal of SO{sub 2}. This Final Technical Report discusses pilot operations, installation and maintenance of the Hg SCEMS instrumentation, and performance results including component and overall removal efficiencies of SO{sub 2}, NO{sub x}, PM and Hg from the flue gas and removal of captured Hg from the co-product fertilizer stream.

  17. Enhancing mercury removal across air pollution control devices for coal-fired power plants by desulfurization wastewater evaporation.

    Science.gov (United States)

    Bin, Hu; Yang, Yi; Cai, Liang; Yang, Linjun; Roszak, Szczepan

    2017-10-09

    Desulfurization wastewater evaporation technology is used to enhance the removal of gaseous mercury (Hg) in conventional air pollution control devices (APCDs) for coal-fired power plants. Studies have affirmed that gaseous Hg is oxidized and removed by selective catalytic reduction (SCR), an electrostatic precipitator (ESP) and wet flue gas desulfurization (WFGD) in a coal-fired thermal experiment platform with WFGD wastewater evaporation. Effects of desulfurization wastewater evaporation position, evaporation temperature and chlorine ion concentration on Hg oxidation were studied as well. The Hg 0 oxidation efficiency was increased ranging from 30% to 60%, and the gaseous Hg removal efficiency was 62.16% in APCDs when wastewater evaporated before SCR. However, the Hg 0 oxidation efficiency was 18.99% and the gaseous Hg removal efficiency was 40.19% in APCDs when wastewater evaporated before ESP. The results show that WFGD wastewater evaporation before SCR is beneficial to improve the efficiency of Hg oxidized and removed in APCDs. Because Hg 2+ can be easily removed in ACPDs and WFGD wastewater in power plants is enriched with chlorine ions, this method realizes WFGD wastewater zero discharge and simultaneously enhances Hg removal in APCDs.

  18. Atmospheric mercury footprints of nations.

    Science.gov (United States)

    Liang, Sai; Wang, Yafei; Cinnirella, Sergio; Pirrone, Nicola

    2015-03-17

    The Minamata Convention was established to protect humans and the natural environment from the adverse effects of mercury emissions. A cogent assessment of mercury emissions is required to help implement the Minamata Convention. Here, we use an environmentally extended multi-regional input-output model to calculate atmospheric mercury footprints of nations based on upstream production (meaning direct emissions from the production activities of a nation), downstream production (meaning both direct and indirect emissions caused by the production activities of a nation), and consumption (meaning both direct and indirect emissions caused by final consumption of goods and services in a nation). Results show that nations function differently within global supply chains. Developed nations usually have larger consumption-based emissions than up- and downstream production-based emissions. India, South Korea, and Taiwan have larger downstream production-based emissions than their upstream production- and consumption-based emissions. Developed nations (e.g., United States, Japan, and Germany) are in part responsible for mercury emissions of developing nations (e.g., China, India, and Indonesia). Our findings indicate that global mercury abatement should focus on multiple stages of global supply chains. We propose three initiatives for global mercury abatement, comprising the establishment of mercury control technologies of upstream producers, productivity improvement of downstream producers, and behavior optimization of final consumers.

  19. MESSENGER'S First Flyby of Mercury

    Science.gov (United States)

    Slavin, James A.

    2008-01-01

    The MESSENGER mission to Mercury offers our first opportunity to explore this planet's miniature magnetosphere since Mariner 10's brief fly-bys in 1974-5. The magnetosphere of Mercury is the smallest in the solar system with its magnetic field typically standing off the solar wind only - 1000 to 2000 km above the surface. An overview of the MESSENGER mission and its January 14th close flyby of Mercury will be provided. Primary science objectives and the science instrumentation will be described. Initial results from MESSENGER'S first flyby on January 14th, 2008 will be discussed with an emphasis on the magnetic field and charged particle measurements.

  20. Mercury Report-Children's exposure to elemental mercury

    Science.gov (United States)

    ... gov . Mercury Background Mercury Report Additional Resources Mercury Report - Children's Exposure to Elemental Mercury Recommend on Facebook ... I limit exposure to mercury? Why was the report written? Children attending a daycare in New Jersey ...

  1. Expert systems in process control systems

    International Nuclear Information System (INIS)

    Wittig, T.

    1987-01-01

    To illustrate where the fundamental difference between expert systems in classical diagnosis and in industrial control lie, the work of process control instrumentation is used as an example for the job of expert systems. Starting from the general process of problem-solving, two classes of expert systems can be defined accordingly. (orig.) [de

  2. Environmental Mercury and Its Toxic Effects

    Directory of Open Access Journals (Sweden)

    Kevin M. Rice

    2014-03-01

    Full Text Available Mercury exists naturally and as a man-made contaminant. The release of processed mercury can lead to a progressive increase in the amount of atmospheric mercury, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years. Mercury poisoning is the result of exposure to mercury or mercury compounds resulting in various toxic effects depend on its chemical form and route of exposure. The major route of human exposure to methylmercury (MeHg is largely through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms. MeHg toxicity is associated with nervous system damage in adults and impaired neurological development in infants and children. Ingested mercury may undergo bioaccumulation leading to progressive increases in body burdens. This review addresses the systemic pathophysiology of individual organ systems associated with mercury poisoning. Mercury has profound cellular, cardiovascular, hematological, pulmonary, renal, immunological, neurological, endocrine, reproductive, and embryonic toxicological effects.

  3. System for controlling apnea

    Energy Technology Data Exchange (ETDEWEB)

    Holzrichter, John F

    2015-05-05

    An implanted stimulation device or air control device are activated by an external radar-like sensor for controlling apnea. The radar-like sensor senses the closure of the air flow cavity, and associated control circuitry signals (1) a stimulator to cause muscles to open the air passage way that is closing or closed or (2) an air control device to open the air passage way that is closing or closed.

  4. Distributed systems status and control

    Science.gov (United States)

    Kreidler, David; Vickers, David

    1990-01-01

    Concepts are investigated for an automated status and control system for a distributed processing environment. System characteristics, data requirements for health assessment, data acquisition methods, system diagnosis methods and control methods were investigated in an attempt to determine the high-level requirements for a system which can be used to assess the health of a distributed processing system and implement control procedures to maintain an accepted level of health for the system. A potential concept for automated status and control includes the use of expert system techniques to assess the health of the system, detect and diagnose faults, and initiate or recommend actions to correct the faults. Therefore, this research included the investigation of methods by which expert systems were developed for real-time environments and distributed systems. The focus is on the features required by real-time expert systems and the tools available to develop real-time expert systems.

  5. Hybrid spacecraft attitude control system

    Directory of Open Access Journals (Sweden)

    Renuganth Varatharajoo

    2016-02-01

    Full Text Available The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.The hybrid subsystem design could be an attractive approach for futurespacecraft to cope with their demands. The idea of combining theconventional Attitude Control System and the Electrical Power System ispresented in this article. The Combined Energy and Attitude ControlSystem (CEACS consisting of a double counter rotating flywheel assemblyis investigated for small satellites in this article. Another hybrid systemincorporating the conventional Attitude Control System into the ThermalControl System forming the Combined Attitude and Thermal ControlSystem (CATCS consisting of a "fluid wheel" and permanent magnets isalso investigated for small satellites herein. The governing equationsdescribing both these novel hybrid subsystems are presented and theironboard architectures are numerically tested. Both the investigated novelhybrid spacecraft subsystems comply with the reference missionrequirements.

  6. Mercury in the environment : a review

    International Nuclear Information System (INIS)

    Goodarzi, F.

    2000-01-01

    Both geogenic and anthropogenic sources are responsible for the input of mercury into the environment. However, mercury comes mostly from geogenic sources and is found naturally in air, water and soil. Crustal degassing results in emission of mercury into the atmosphere. Mercury in water and soil is due mostly to input from sedimentary rocks. Mercury in lake sediments is related mainly to input by country rock and anthropogenic activities such as agriculture. The mercury content of coal is similar to or less than the amount found in the earths crust. Natural charcoal is also able to capture mercury at low temperature combustion. The amount of mercury emitted from the stack of coal-fired power plants is related to the nature of the milled coal and its mineralogical and elemental content. Mercury emissions originating from the combustion of coal from electric utility power plants are considered to be among the greatest contributors to global mercury air emissions. In order to quantify the impact the electric power industry has on the environment, information regarding mercury concentrations in coal and their speciation is needed. For this reason the author examined the behaviour of mercury in three coal samples ashed at increasing temperatures. Mercury removal from coal-fired power plants ranges from 10 to 50 per cent by fabric filters and 20 to 95 per cent by FGD systems. This data will help in regulating emissions of hazardous air pollutants from electric utility steam generating units and will potentially provide insight into the industry's contribution to the global mercury burden. 50 refs

  7. Diagnostic, reliablility and control systems

    CERN Document Server

    Leondes

    2014-01-01

    1. Explicit-Model-Based Fault Detection Method in Industrial Plants 2. Soft Sensor: An Effective Approach to Improve Control 3. Techniques in Soft Computing and Their Utilization in Mechatronic Products 4. Techniques in the Control of Interconnected Plants 5. A Mechatronic Systems Approach to Controlling Robotic Systems with Actuator Dynamics 6. Process and Control Design for Fast Coordinate Measuring Machines 7. Techniques in the Stability of Mechatronic Systems with Sensor or Actuator Failure.

  8. Final report for the Central Mercury Treatment System in Building 9623 at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1997-02-01

    This document discusses the construction of the Central Mercury Treatment System (CMTS) in Building 9623 at the Y-12 Plant, the remediation activities involved, waste generated from the project, and the monitoring schedule of the CMTS. As part of the Reduction of Mercury in Plant Effluent Program, the project treats groundwater contaminated with mercury from Buildings 9201-4, 9201-5, and 9204-4 at the Y-12 Plant to meet National Pollutant Discharge Elimination System (NPDES) Permit limits for discharge to East Fork Poplar Creek. The CMTS, located in Building 9623, will treat water from the sumps of buildings in which mercury was used in operations and which have been shown to be significant contributors to the overall levels of mercury in plant effluents. This project was anticipated when the NPDES Permit was issued, and the contamination limits and frequency of monitoring for the system discharge are detailed in the permit as Outfall 551. This project was performed as an Incentive Task Order and included the advance procurement of the carbon columns, removal of existing equipment in Building 9623, and system installation and checkout. Construction activities for installing the system started in January 1996 after the area in Building 9623 had been cleared of existing, obsolete equipment. The CMTS became operational on November 26, 1996, well ahead of the permit start date of January 1, 1998. The early completion date allows Hg concentrations in EFPC to be evaluated to determine whether further actions are required to meet NPDES permit limits for reduced Hg loading to the creek

  9. Method validation for control determination of mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry.

    Science.gov (United States)

    Torres, Daiane Placido; Martins-Teixeira, Maristela Braga; Cadore, Solange; Queiroz, Helena Müller

    2015-01-01

    A method for the determination of total mercury in fresh fish and shrimp samples by solid sampling thermal decomposition/amalgamation atomic absorption spectrometry (TDA AAS) has been validated following international foodstuff protocols in order to fulfill the Brazilian National Residue Control Plan. The experimental parameters have been previously studied and optimized according to specific legislation on validation and inorganic contaminants in foodstuff. Linearity, sensitivity, specificity, detection and quantification limits, precision (repeatability and within-laboratory reproducibility), robustness as well as accuracy of the method have been evaluated. Linearity of response was satisfactory for the two range concentrations available on the TDA AAS equipment, between approximately 25.0 and 200.0 μg kg(-1) (square regression) and 250.0 and 2000.0 μg kg(-1) (linear regression) of mercury. The residues for both ranges were homoscedastic and independent, with normal distribution. Correlation coefficients obtained for these ranges were higher than 0.995. Limits of quantification (LOQ) and of detection of the method (LDM), based on signal standard deviation (SD) for a low-in-mercury sample, were 3.0 and 1.0 μg kg(-1), respectively. Repeatability of the method was better than 4%. Within-laboratory reproducibility achieved a relative SD better than 6%. Robustness of the current method was evaluated and pointed sample mass as a significant factor. Accuracy (assessed as the analyte recovery) was calculated on basis of the repeatability, and ranged from 89% to 99%. The obtained results showed the suitability of the present method for direct mercury measurement in fresh fish and shrimp samples and the importance of monitoring the analysis conditions for food control purposes. Additionally, the competence of this method was recognized by accreditation under the standard ISO/IEC 17025.

  10. Mercury Exposure among Garbage Workers in Southern Thailand

    Directory of Open Access Journals (Sweden)

    Somsiri Decharat

    2012-12-01

    Conclusion: Changing garbage workers’ hygiene habits can reduce urinary mercury levels. Personal hygiene is important, and should be stressed in education programs. Employers should institute engineering controls to reduce urinary mercury levels among garbage workers.

  11. Application of 137Cs and 210Pb in tracing the fate of mercury in a river-reservoir system

    International Nuclear Information System (INIS)

    Turner, R.R.; Olsen, C.R.

    1985-01-01

    The vertical distribution of 137 Cs and 210 Pb in sediment cores from the Tennessee River-Reservoir System (USA) was used to trace the fate of Hg discharged from two upstream facilities and to resolve the relative contribution from each facility. Discharges since 1943 at the Oak Ridge nuclear facilities left a clear record of releases for Hg and 137 Cs in undisturbed downstream sediments. High releases in the 1950s are reflected in well-defined peaks, located 30 cm or more below the sediment-water interface, which can now be used to accurately date sediment layers. Chronologies based on 210 Pb gave sediment ages concordant with those based on the release histories and helped to resolve mercury contributions from a chloralkali plant located 150 km downstream of the Oak Ridge facilities

  12. Small Mercury Relativity Orbiter

    Science.gov (United States)

    Bender, Peter L.; Vincent, Mark A.

    1989-01-01

    The accuracy of solar system tests of gravitational theory could be very much improved by range and Doppler measurements to a Small Mercury Relativity Orbiter. A nearly circular orbit at roughly 2400 km altitude is assumed in order to minimize problems with orbit determination and thermal radiation from the surface. The spacecraft is spin-stabilized and has a 30 cm diameter de-spun antenna. With K-band and X-band ranging systems using a 50 MHz offset sidetone at K-band, a range accuracy of 3 cm appears to be realistically achievable. The estimated spacecraft mass is 50 kg. A consider-covariance analysis was performed to determine how well the Earth-Mercury distance as a function of time could be determined with such a Relativity Orbiter. The minimum data set is assumed to be 40 independent 8-hour arcs of tracking data at selected times during a two year period. The gravity field of Mercury up through degree and order 10 is solved for, along with the initial conditions for each arc and the Earth-Mercury distance at the center of each arc. The considered parameters include the gravity field parameters of degree 11 and 12 plus the tracking station coordinates, the tropospheric delay, and two parameters in a crude radiation pressure model. The conclusion is that the Earth-Mercury distance can be determined to 6 cm accuracy or better. From a modified worst-case analysis, this would lead to roughly 2 orders of magnitude improvement in the knowledge of the precession of perihelion, the relativistic time delay, and the possible change in the gravitational constant with time.

  13. Mercury in Arctic snow: Quantifying the kinetics of photochemical oxidation and reduction

    International Nuclear Information System (INIS)

    Mann, E.A.; Mallory, M.L.; Ziegler, S.E.; Tordon, R.; O'Driscoll, N.J.

    2015-01-01

    Controlled experiments were performed with frozen and melted Arctic snow to quantify relationships between mercury photoreaction kinetics, ultra violet (UV) radiation intensity, and snow ion concentrations. Frozen (− 10 °C) and melted (4 °C) snow samples from three Arctic sites were exposed to UV (280–400 nm) radiation (1.26–5.78 W · m −2 ), and a parabolic relationship was found between reduction rate constants in frozen and melted snow with increasing UV intensity. Total photoreduced mercury in frozen and melted snow increased linearly with greater UV intensity. Snow with the highest concentrations of chloride and iron had larger photoreduction and photooxidation rate constants, while also having the lowest Hg(0) production. Our results indicate that the amount of mercury photoreduction (loss from snow) is the highest at high UV radiation intensities, while the fastest rates of mercury photoreduction occurred at both low and high intensities. This suggests that, assuming all else is equal, earlier Arctic snow melt periods (when UV intensities are less intense) may result in less mercury loss to the atmosphere by photoreduction and flux, since less Hg(0) is photoproduced at lower UV intensities, thereby resulting in potentially greater mercury transport to aquatic systems with snowmelt. - Highlights: • Mercury photochemical kinetics were studied in frozen and melted Arctic snow. • UV-induced photoreduction and photooxidation rate constants were quantified. • Chloride ion, iron, and DOC influence mercury photoreactions in snow. • Frozen and melted snow have different mercury photoreduction characteristics. • Kinetic information provided can be used to model mercury fate in the Arctic

  14. Fate of Mercury in Synthetic Gypsum Used for Wallboard Production

    Energy Technology Data Exchange (ETDEWEB)

    Jessica Sanderson

    2007-12-31

    This report presents and discusses results from the project 'Fate of Mercury in Synthetic Gypsum Used for Wallboard Production', performed at five different full-scale commercial wallboard plants. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasing the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies involve the capture of mercury in FGD systems. The objective of this study has been to determine whether any mercury is released into the atmosphere at wallboard manufacturing plants when the synthetic gypsum material is used as a feedstock for wallboard production. The project has been co-funded by the U.S. DOE National Energy Technology Laboratory (Cooperative Agreement DE-FC26-04NT42080), USG Corporation, and EPRI. USG Corporation is the prime contractor, and URS Group is a subcontractor. The project scope included seven discrete tasks, each including a test conducted at various USG wallboard plants using synthetic gypsum from different wet FGD systems. The project was originally composed of five tasks, which were to include (1) a base-case test, then variations representing differing power plant: (2) emissions control configurations, (3) treatment of fine gypsum particles, (4) coal types, and (5) FGD reagent types. However, Task 5,could not be conducted as planned and instead was conducted at conditions similar to Task 3. Subsequently an opportunity arose to test gypsum produced from the Task 5 FGD system, but with an additive expected to impact the stability of mercury, so Task 6 was added to the project. Finally, Task 7 was added to evaluate synthetic gypsum produced at a power plant from an

  15. Controlling dynamics in diatomic systems

    Indian Academy of Sciences (India)

    Keywords. Iterative method; optimal control theory; diatomic systems; quantum control. Abstract. Controlling molecular energetics using laser pulses is exemplified for nuclear motion in two different diatomic systems. The problem of finding the optimized field for maximizing a desired quantum dynamical target is formulated ...

  16. The ATLAS Detector Control System

    International Nuclear Information System (INIS)

    Lantzsch, K; Braun, H; Hirschbuehl, D; Kersten, S; Arfaoui, S; Franz, S; Gutzwiller, O; Schlenker, S; Tsarouchas, C A; Mindur, B; Hartert, J; Zimmermann, S; Talyshev, A; Oliveira Damazio, D; Poblaguev, A; Martin, T; Thompson, P D; Caforio, D; Sbarra, C; Hoffmann, D

    2012-01-01

    The ATLAS experiment is one of the multi-purpose experiments at the Large Hadron Collider (LHC) at CERN, constructed to study elementary particle interactions in collisions of high-energy proton beams. Twelve different sub detectors as well as the common experimental infrastructure are controlled and monitored by the Detector Control System (DCS) using a highly distributed system of 140 server machines running the industrial SCADA product PVSS. Higher level control system layers allow for automatic control procedures, efficient error recognition and handling, manage the communication with external systems such as the LHC controls, and provide a synchronization mechanism with the ATLAS data acquisition system. Different databases are used to store the online parameters of the experiment, replicate a subset used for physics reconstruction, and store the configuration parameters of the systems. This contribution describes the computing architecture and software tools to handle this complex and highly interconnected control system.

  17. The ATLAS Detector Control System

    Science.gov (United States)

    Lantzsch, K.; Arfaoui, S.; Franz, S.; Gutzwiller, O.; Schlenker, S.; Tsarouchas, C. A.; Mindur, B.; Hartert, J.; Zimmermann, S.; Talyshev, A.; Oliveira Damazio, D.; Poblaguev, A.; Braun, H.; Hirschbuehl, D.; Kersten, S.; Martin, T.; Thompson, P. D.; Caforio, D.; Sbarra, C.; Hoffmann, D.; Nemecek, S.; Robichaud-Veronneau, A.; Wynne, B.; Banas, E.; Hajduk, Z.; Olszowska, J.; Stanecka, E.; Bindi, M.; Polini, A.; Deliyergiyev, M.; Mandic, I.; Ertel, E.; Marques Vinagre, F.; Ribeiro, G.; Santos, H. F.; Barillari, T.; Habring, J.; Huber, J.; Arabidze, G.; Boterenbrood, H.; Hart, R.; Iakovidis, G.; Karakostas, K.; Leontsinis, S.; Mountricha, E.; Ntekas, K.; Filimonov, V.; Khomutnikov, V.; Kovalenko, S.; Grassi, V.; Mitrevski, J.; Phillips, P.; Chekulaev, S.; D'Auria, S.; Nagai, K.; Tartarelli, G. F.; Aielli, G.; Marchese, F.; Lafarguette, P.; Brenner, R.

    2012-12-01

    The ATLAS experiment is one of the multi-purpose experiments at the Large Hadron Collider (LHC) at CERN, constructed to study elementary particle interactions in collisions of high-energy proton beams. Twelve different sub detectors as well as the common experimental infrastructure are controlled and monitored by the Detector Control System (DCS) using a highly distributed system of 140 server machines running the industrial SCADA product PVSS. Higher level control system layers allow for automatic control procedures, efficient error recognition and handling, manage the communication with external systems such as the LHC controls, and provide a synchronization mechanism with the ATLAS data acquisition system. Different databases are used to store the online parameters of the experiment, replicate a subset used for physics reconstruction, and store the configuration parameters of the systems. This contribution describes the computing architecture and software tools to handle this complex and highly interconnected control system.

  18. Mercury Information Clearinghouse

    Energy Technology Data Exchange (ETDEWEB)

    Chad A. Wocken; Michael J. Holmes; Dennis L. Laudal; Debra F. Pflughoeft-Hassett; Greg F. Weber; Nicholas V. C. Ralston; Stanley J. Miller; Grant E. Dunham; Edwin S. Olson; Laura J. Raymond; John H. Pavlish; Everett A. Sondreal; Steven A. Benson

    2006-03-31

    The Canadian Electricity Association (CEA) identified a need and contracted the Energy & Environmental Research Center (EERC) to create and maintain an information clearinghouse on global research and development activities related to mercury emissions from coal-fired electric utilities. With the support of CEA, the Center for Air Toxic Metals{reg_sign} (CATM{reg_sign}) Affiliates, and the U.S. Department of Energy (DOE), the EERC developed comprehensive quarterly information updates that provide a detailed assessment of developments in the various areas of mercury monitoring, control, policy, and research. A total of eight topical reports were completed and are summarized and updated in this final CEA quarterly report. The original quarterly reports can be viewed at the CEA Web site (www.ceamercuryprogram.ca). In addition to a comprehensive update of previous mercury-related topics, a review of results from the CEA Mercury Program is provided. Members of Canada's coal-fired electricity generation sector (ATCO Power, EPCOR, Manitoba Hydro, New Brunswick Power, Nova Scotia Power Inc., Ontario Power Generation, SaskPower, and TransAlta) and CEA, have compiled an extensive database of information from stack-, coal-, and ash-sampling activities. Data from this effort are also available at the CEA Web site and have provided critical information for establishing and reviewing a mercury standard for Canada that is protective of environment and public health and is cost-effective. Specific goals outlined for the CEA mercury program included the following: (1) Improve emission inventories and develop management options through an intensive 2-year coal-, ash-, and stack-sampling program; (2) Promote effective stack testing through the development of guidance material and the support of on-site training on the Ontario Hydro method for employees, government representatives, and contractors on an as-needed basis; (3) Strengthen laboratory analytical capabilities through

  19. Framework for control system development

    International Nuclear Information System (INIS)

    Cork, C.; Nishimura, Hiroshi

    1992-01-01

    Control systems being developed for the present generation of accelerators will need to adapt to changing machine and operating state conditions. Such systems must also be capable of evolving over the life of the accelerator operation. In this paper we present a framework for the development of adaptive control systems

  20. Minicomputer controlled test system for process control and monitoring systems

    International Nuclear Information System (INIS)

    Worster, L.D.

    A minicomputer controlled test system for testing process control and monitoring systems is described. This system, in service for over one year, has demonstrated that computerized control of such testing has a real potential for expanding the scope of the testing, improving accuracy of testing, and significantly reducing the time required to do the testing. The test system is built around a 16-bit minicomputer with 12K of memory. The system programming language is BASIC with the addition of assembly level routines for communication with the peripheral devices. The peripheral devices include a 100 channel scanner, analog-to-digital converter, visual display, and strip printer. (auth)

  1. The GSI control system

    International Nuclear Information System (INIS)

    Krause, U.; Schaa, V.; Steiner, R.

    1992-01-01

    The GSI accelerator facility consists of an old linac and two modern machines, a synchrotron and a storage ring. It is operated from one control room. Only three operators at a time have to keep it running with only little assistance from machine specialists in daytime. So the control tools must provide a high degree of abstraction and modeling to relieve the operators from details on the device level. The program structures to achieve this are described in this paper. A coarse overview of the control architecture is given. (author)

  2. Controlling Uncertain Dynamical Systems

    Indian Academy of Sciences (India)

    Author Affiliations. N Ananthkrishnan1 Rashi Bansal2. Head, CAE Analysis & Design Zeus Numerix Pvt Ltd. M-03, SINE, IIT Bombay Powai Mumbai 400076, India. MTech (Aerospace Engineering) with specialization in Dynamics & Control from IIT Bombay.

  3. Can homeopathically prepared mercury cause symptoms in healthy volunteers? A randomized, double-blind placebo-controlled trial.

    Science.gov (United States)

    Vickers, A J; van Haselen, R; Heger, M

    2001-04-01

    To pilot a method for determining whether homeopathically prepared mercury causes more symptoms (a "drug proving") in healthy volunteers than placebo. One hundred and eighteen (118) healthy volunteers ages 18 to 65 were recruited by local advertising. Subjects unfamiliar with homeopathy undertook a 1-week single-blind placebo run-in, a 1-week of double-blind, randomized treatment on either homeopathically prepared mercury 12C or placebo, and a third week of placebo run-out. Each day, symptoms were recorded on a checklist that included both true mercury symptoms and symptoms not expected to be caused by mercury (false symptoms). Additional symptoms were assessed by open reporting. Outcome was assessed by calculating a score for each day as the number of true symptoms minus the number of false symptoms. The mean score during placebo was then subtracted from the mean score for weeks two and three of the trial. Fourteen (14) subjects dropped out during placebo run-in. The remaining 104 completed the trial. Baseline comparability was good. Mean difference score was -0.125 (SD 3.47) for mercury and -0.221 (SD 3.01) for placebo (p > 0.2). No significant differences between groups were found for the number of subjects meeting predefined criteria for a drug-proving reaction. This pilot study failed to find evidence that mercury 12C causes significantly more symptoms in healthy volunteers than placebo. Questionnaires with a limited number of gross symptoms do not seem to be an appropriate methodological technique in drug proving research. If drug-proving phenomena exist, they appear to be rare.

  4. Delays and networked control systems

    CERN Document Server

    Hetel, Laurentiu; Daafouz, Jamal; Johansson, Karl

    2016-01-01

    This edited monograph includes state-of-the-art contributions on continuous time dynamical networks with delays. The book is divided into four parts. The first part presents tools and methods for the analysis of time-delay systems with a particular attention on control problems of large scale or infinite-dimensional systems with delays. The second part of the book is dedicated to the use of time-delay models for the analysis and design of Networked Control Systems. The third part of the book focuses on the analysis and design of systems with asynchronous sampling intervals which occur in Networked Control Systems. The last part of the book exposes several contributions dealing with the design of cooperative control and observation laws for networked control systems. The target audience primarily comprises researchers and experts in the field of control theory, but the book may also be beneficial for graduate students. .

  5. Control systems with network delay

    OpenAIRE

    Şabanoviç, Asif; Sabanovic, Asif; Ohnishi, Kouhei; Yashiro, Daisuke; Acer, Merve; Ş.-Behliloviç, Nadira; S.-Behlilovic, Nadira

    2009-01-01

    In this paper motion control systems with delay in measurement and control channels are discussed and a new structure of the observer-predictor is proposed. The feature of the proposed system is enforcement of the convergence in both the estimation and the prediction of the plant output in the presence of the variable, unknown delay in both measurement and in the control channels. The estimation is based on the available data – undelayed control input, the delayed measurement of position o...

  6. Asynchronous control for networked systems

    CERN Document Server

    Rubio, Francisco; Bencomo, Sebastián

    2015-01-01

    This book sheds light on networked control systems; it describes different techniques for asynchronous control, moving away from the periodic actions of classical control, replacing them with state-based decisions and reducing the frequency with which communication between subsystems is required. The text focuses specially on event-based control. Split into two parts, Asynchronous Control for Networked Systems begins by addressing the problems of single-loop networked control systems, laying out various solutions which include two alternative model-based control schemes (anticipatory and predictive) and the use of H2/H∞ robust control to deal with network delays and packet losses. Results on self-triggering and send-on-delta sampling are presented to reduce the need for feedback in the loop. In Part II, the authors present solutions for distributed estimation and control. They deal first with reliable networks and then extend their results to scenarios in which delays and packet losses may occur. The novel ...

  7. Standardization of detector control systems

    International Nuclear Information System (INIS)

    Fukunaga, Chikara

    2000-01-01

    Current and future detectors for high-energy and/or nuclear physics experiments require highly intelligent detector control systems. In order to reduce resources, the construction of a standardized template for the control systems based on the commercially available superviser control and data acquisition (SCADA) system has been proposed. The possibility of constructing this template is discussed and several key issues for evaluation of SCADA as the basis for such a template are presented. (author)

  8. Mercury Detection with Gold Nanoparticles: Investigating Fundamental Phenomena and Expanding Applications

    Science.gov (United States)

    Crosby, Jeffrey Scott

    Mercury is a pollutant of grave concern with well documented neurological and developmental health impacts. Better sensing methodology would improve detection and control of mercury and thus reduce its health burden. Gold nanoparticles provide a sensing medium with potential advantages in sensitivity, selectivity, robustness, and cost over established techniques. Mercury readily adsorbs onto the surface of the gold changing the localized surface plasmon resonance which is measured as a shift in the peak optical absorbance wavelength. This shift is dependent on the mercury concentration and predictable with classical electromagnetism. This work investigates some of the fundamental relationships driving sensor response. The effects of mass transfer and surface kinetics on mercury/gold nanoparticle adsorption are determined with analytical models and experimental results based on impinging flow geometry. To decouple mass transfer and surface kinetics adsorption, electrical analogy models are constructed and fit to the experimental data. The models can account for variations in flow conditions and surface coatings on the nanoparticles. These models are generalizable to other systems. Results from these fundamental investigations are used to improve and extend sensor performance. The time response or collection efficiency is optimized depending on system requirements. Using the knowledge gained, the applicability of gold nanoparticle mercury sensors is extended to a fiber optic based system and aqueous detection. Nanorods deposited on the surface of a fiber optic cable have a linear response with concentration and are able to detect mercury down to 1.0 mug/m3. The modification of an established oxidation/reduction scheme for use with the sensor allows for the detection of ionic and organic mercury from water samples which ordinarily would not be reactive with gold nanoparticles. The aqueous sensor was able to detect mercury below the EPA's drinking water limit.

  9. REDUCTION OF INHERENT MERCURY EMISSIONS IN PC COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    John C. Kramlich; Rebecca N. Sliger

    2000-08-26

    Oxidized mercury has been shown to be more easily removed from power plant flue gas by existing air pollution control equipment (e.g., wet scrubbers) than elemental mercury. The factors that determine how mercury is converted to the oxidized form in practical systems are, however, unknown. The present research focuses on developing an elementary, homogeneous mechanism that describes the oxidation of mercury by chlorine species as it occurs in practical furnaces. The goal is to use this mechanism (1) as a component in an overall homogeneous/heterogeneous mechanism that describes mercury behavior, and (2) to suggest low cost/low impact means of promoting mercury oxidation in furnaces. The results suggest an important role for Hg+Cl {r_arrow} HgCl and HgCl + Cl {r_arrow} HgCl{sub 2}. Here, the Cl is derived by radical attack on HCl in the high-temperature environment. The results suggest that the oxidation occurs during the time that the gases cool to room temperature. The high Cl concentrations from the flame persist into the quench region and provide for the oxidation of Hg to HgCl{sub 2} under lower temperatures where the products are stable. Under this mechanism, no significant HgCl{sub 2} is actually present at the higher temperatures where oxidized mercury is often reported in the literature (e.g., 900 C). Instead, all oxidation occurs as these gases are quenched. The results suggest that means of promoting Cl concentrations in the furnace will increase oxidation.

  10. Control integral systems; Sistemas integrales de control

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, Estrella [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-12-31

    Almost two third of the electric power generation in Mexico are obtained from hydrocarbons, for that reasons Comision Federal de Electricidad (CFE) dedicated special commitment in modernizing the operation of fossil fuel central stations. In attaining this objective the control systems play a fundamental roll, from them depend a good share of the reliability and the efficiency of the electric power generation process, as well as the extension of the equipment useful life. Since 1984 the Instituto de Investigaciones Electricas (IIE) has been working, upon the request of CFE, on the development of digital control systems. To date it has designed and implemented a logic control system for gas burners, which controls 32 burners of the Unit 4 boiler of the Generation Central of Valle de Mexico and two systems for distributed control for two combined cycle central stations, which are: Dos Bocas, Veracruz Combined cycle central, and Gomez Palacio, Durango combined cycle central. With these two developments the IIE enters the World tendency of implementing distributed control systems for the fossil fuel power central update [Espanol] Casi las dos terceras partes de la generacion electrica en Mexico se obtienen a partir de hidrocarburos, es por eso que la Comision Federal de Electricidad (CFE) puso especial empeno en modernizar la operacion de las centrales termoelectricas de combustibles fosiles. En el logro de este objetivo los sistemas de control desempenan un papel fundamental, de ellos depende una buena parte la confiabilidad y la eficiencia en el proceso de generacion de energia electrica, asi como la prolongacion de la vida util de los equipos. Desde 1984 el Instituto de Investigaciones Electricas (IIE) ha trabajado, a solicitud de la CFE, en el desarrollo de sistemas digitales de control. A la fecha se han disenado e implantado un sistema de control logico de quemadores de gas, el cual controla 32 quemadores de la caldera de la unidad 4 de la central de generacion

  11. EMISSION TEST REPORT- FIELD TEST OF CARBON INJECTION FOR MERCURY CONTROL, CAMDEN COUNTY MUNICIPAL WASTE COMBUSTOR

    Science.gov (United States)

    The report gives results of parametric test to evaluate the injection powdered activated carbon to control volatile pollutants in municipal waste combustor (MWC) flue gas. he tests were conducted at a spray dryer absorber/electrostatic precipitator (SD/ESP)-equipped MWC in Camden...

  12. Surface-air mercury fluxes across Western North America: A synthesis of spatial trends and controlling variables

    Science.gov (United States)

    Eckley, Chris S.; Tate, Michael T.; Lin, Che-Jen; Gustin, Mae S.; Dent, Stephen; Eagles-Smith, Collin A.; Lutz, Michelle A; Wickland, Kimberly; Wang, Bronwen; Gray, John E.; Edwards, Grant; Krabbenhoft, David P.; Smith, David

    2016-01-01

    Mercury (Hg) emission and deposition can occur to and from soils, and are an important component of the global atmospheric Hg budget. This paper focuses on synthesizing existing surface-air Hg flux data collected throughout the Western North American region and is part of a series of geographically focused Hg synthesis projects. A database of existing Hg flux data collected using the dynamic flux chamber (DFC) approach from almost a thousand locations was created for the Western North America region. Statistical analysis was performed on the data to identify the important variables controlling Hg fluxes and to allow spatiotemporal scaling. The results indicated that most of the variability in soil-air Hg fluxes could be explained by variations in soil-Hg concentrations, solar radiation, and soil moisture. This analysis also identified that variations in DFC methodological approaches were detectable among the field studies, with the chamber material and sampling flushing flow rate influencing the magnitude of calculated emissions. The spatiotemporal scaling of soil-air Hg fluxes identified that the largest emissions occurred from irrigated agricultural landscapes in California. Vegetation was shown to have a large impact on surface-air Hg fluxes due to both a reduction in solar radiation reaching the soil as well as from direct uptake of Hg in foliage. Despite high soil Hg emissions from some forested and other heavily vegetated regions, the net ecosystem flux (soil flux + vegetation uptake) was low. Conversely, sparsely vegetated regions showed larger net ecosystem emissions, which were similar in magnitude to atmospheric Hg deposition (except for the Mediterranean California region where soil emissions were higher). The net ecosystem flux results highlight the important role of landscape characteristics in effecting the balance between Hg sequestration and (re-)emission to the atmosphere.

  13. Environmental mercury problem

    Energy Technology Data Exchange (ETDEWEB)

    D' Itri, F.M.

    1972-01-01

    The urgent need to eliminate or greatly reduce the discharge of mercury into the environment is paramount to the health and well being of man. That all forms of mercury are hazardous is widely recognized, but what is more devastating to our society is that all forms of mercury appear to have the potential to be converted in to highly toxic monomethylmercury, or dimethylmercury. This paper examined the historical uses of mercury, the background concentrations of mercury, the analytical methods for the determination of mercury, the contamination of the food chain by mercury, the biological methylation of mercury, the decontamination and restoration of mercury polluted areas, the epidemiology and toxicology of mercury, and the chronology of the world's mercury poisoning problem.

  14. Reactor power control system

    International Nuclear Information System (INIS)

    Tomisawa, Teruaki.

    1981-01-01

    Purpose: To restore reactor-power condition in a minimum time after a termination of turbine bypass by reducing the throttling of the reactor power at the time of load-failure as low as possible. Constitution: The transient change of the internal pressure of condenser is continuously monitored. When a turbine is bypassed, a speed-control-command signal for a coolant recirculating pump is generated according as the internal pressure of the condenser. When the signal relating to the internal pressure of the condenser indicates insufficient power, a reactor-control-rod-drive signal is generated. (J.P.N.)

  15. Ground Control System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    Eric Loros

    2001-07-31

    The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently maintainable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System

  16. Ground Control System Description Document

    International Nuclear Information System (INIS)

    Eric Loros

    2001-01-01

    The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently maintainable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System

  17. Mercury Methylation and Detoxification by Novel Microorganisms in Mercury Enriched Mesothermal Springs

    Science.gov (United States)

    Gionfriddo, C. M.; Krabbenhoft, D. P.; Stott, M.; Wick, R. R.; Schultz, M. B.; Holt, K. E.; Moreau, J. W.

    2015-12-01

    Hot springs and fumaroles release significant quantities of aqueous and gaseous mercury into the environment. Yet few studies have looked at the microbial underpinnings of mercury transformations in geothermal settings. Recent advancements in culture-independent molecular techniques, such as ultra-high-throughput sequencing, allow us to delve deeply into the functional and phylogenetic make-up of these extreme environments. Here we present results from deep metagenomic sequencing of geothermal microbial communities cycling mercury, focussing on the connections between putative metabolisms and mercury methylation, and the evolution of the mer-operon. Presented are data from two adjacent, acidic (pHNew Zealand), extremely enriched in total mercury (>1000 ng L-1), and varying methylmercury concentrations (1-10 ng L-1). Microbial communities of both springs are dominated by mercury resistant acidophilic, sulfur- and iron-cycling microbes: Acidithiobacillus, Thiomonas, and Thermoplasma. Mercury methylation genes (hgcAB) were only detected in the cooler spring (ΔT~10 °C), with an order of magnitude greater methylmercury (10 ng L-1). The hgcAB genes have no known closest relatives (40°C), and methylmercury concentration. We conclude that the relative amount of mercury methylation in each hot spring is controlled by the presence of methylating bacteria and archaea, the release of bioavailable mercury species from sulfide minerals, counterbalanced by microbial mercury demethylation and reduction and mercury sulfide mineralization.

  18. An Epidemiological Study of Mercury Sensitization

    Directory of Open Access Journals (Sweden)

    Kazuhiro Sato

    1997-01-01

    Full Text Available Mercury sensitization has been historically in question and may be related to recent increases of type I allergic diseases. To clarify the epidemiological factors of mercury sensitization, we investigated factors relating to mercury sensitization in 215 medical students. Their allergic symptoms, family histories and lifestyles were studied by questionnaire. Patch tests were performed with HgCI2 (0.05% aq. and NiS04 (5% aq.. Anti- Dermatophagoides and anti-Crypfomeria pollen IgE antibodies in sera were also measured. Urinary mercury concentrations were measured in 25 mercury sensitized and 44 non-sensitized subjects (controls. Hair mercury concentrations were also measured in 19 sensitized and 22 non-sensitized subjects. While the positive rate of nickel was 6.0% (13/215, that of mercury was high (13.0%; 28/215. The subjects' individual histories of allergic rhinitis, eczema, urticaria and allergic conjunctivitis were significantly associated with family histories of these conditions (P<0.01, P<0.005 and P<0.005, respectively, as reported in the literature. However, no allergen- specific antibody positivity or past history of allergic disease was associated with mercury sensitization. Mercury sensitized subjects had experienced eczema caused by cosmetics, shampoos, soaps and haircreams significantly more frequently (P<0.05. The history of mercurochrome usage was not associated with mercury sensitization. The number of teeth treated with metals in mercury sensitized subjects was significantly higher than that in the control group (6.8±4.3 vs 4.8±1; P<0.05. There were significant differences in urinary mercury concentrations (specific gravity adjusted levels between mercury sensitized subjects and non-sensitized subjects (2.0±0.9 and 1.3±0.6 (xg/L, respectively; P<0.001. There were also significant differences in hair mercury concentrations between mercury sensitized and non-sensitized subjects (2.0±0.9 and 1.2±0.5 μg/g, respectively; P<0

  19. INSTRUCTIONAL QUALITY CONTROL SYSTEMS.

    Science.gov (United States)

    MONROE, BRUCE

    A REVIEW OF THE LITERATURE, A MAIL SURVEY, AND A TEXTUAL ANALYSIS OF JUNIOR COLLEGE DOCUMENTS INDICATE THAT, WHILE CALIFORNIA JUNIOR COLLEGES ARE CONCERNED ABOUT THE QUALITY AND EFFECTIVENESS OF INSTRUCTION, CONTROL OF THAT QUALITY IS RARELY A SYSTEMATIC ROUTINE ENTERPRISE BASED ON EXAMINATION OF BEHAVIOR CHANGES IN STUDENTS FOLLOWING INSTRUCTION.…

  20. Systems and Control Engineering

    Indian Academy of Sciences (India)

    discipline has played critical roles in technological advances over the last few decades. If not for modern control theory, aircraft would not be flying as far or as fast; manufactured goods, from paper to steel to gasoline to Mars Bars, would not be as readily available; Rover would still be just a dog's name; ... the list is endless.

  1. Effects of liming and ash recycling on the outflow of mercury from forest soils - a theoretical study

    International Nuclear Information System (INIS)

    Andersson, Arne; Nilsson, Ingvar

    1994-01-01

    In this report, a theoretical review is made of the probable effects that spreading of lime and woodash in forests will have on the turnover of mercury in soil and on the outflow of mercury into water systems. As a result of historic emissions of mercury into the atmosphere, a large proportion of Swedish forest land has significantly increased concentrations of mercury, which is gradually leaching into lakes and watercourses. If an increased application of lime or woodash to forest soils were to result in a major change in the outflow of mercury, it could in time have a considerable effect on the mercury concentrations in lake fish. The fish in a large number of lakes in the southern part of Sweden already have mercury concentrations which are so high as to make them unsuitable for use as food. In conclusion, the theoretical assessment indicates in general that any effects on the mercury situation in lakes as a result of liming or woodash treatment of forest land are marginal or towards the positive side. It is not likely that these treatments increases the outflow of organic matter from soil. Any worsening of the mercury situation in lakes and watercourses will therefore hardly be the result of soil changes, but rather of processes in lakes and streams. Most of the evidence, however suggests that liming/ash treatment has predominantly positive effects with regard to the lake processes that control mercury levels in fish. At this juncture, available experience indicates that the mercury situation in the environment is in no way a decisive factor in determining where and how lime or ash should be applied to forest land. 64 refs, 2 figs

  2. Automatic flow-batch system for cold vapor atomic absorption spectroscopy determination of mercury in honey from Argentina using online sample treatment.

    Science.gov (United States)

    Domínguez, Marina A; Grünhut, Marcos; Pistonesi, Marcelo F; Di Nezio, María S; Centurión, María E

    2012-05-16

    An automatic flow-batch system that includes two borosilicate glass chambers to perform sample digestion and cold vapor atomic absorption spectroscopy determination of mercury in honey samples was designed. The sample digestion was performed by using a low-cost halogen lamp to obtain the optimum temperature. Optimization of the digestion procedure was done using a Box-Behnken experimental design. A linear response was observed from 2.30 to 11.20 μg Hg L(-1). The relative standard deviation was 3.20% (n = 11, 6.81 μg Hg L(-1)), the sample throughput was 4 sample h(-1), and the detection limit was 0.68 μg Hg L(-1). The obtained results with the flow-batch method are in good agreement with those obtained with the reference method. The flow-batch system is simple, allows the use of both chambers simultaneously, is seen as a promising methodology for achieving green chemistry goals, and is a good proposal to improving the quality control of honey.

  3. Effect of probenecid on the transport of methyl mercury in erythrocytes by the organic anion transport system

    Energy Technology Data Exchange (ETDEWEB)

    Wu Guang [Biochemistry Section, National Institute for Minamata Disease, Minamata, Kumamoto (Japan)

    1997-02-01

    The uptake of methyl mercury (MeHg) by isolated erythrocytes from rats was studied at 5 and 20 C. The Na{sup +} ion was used to examine exerted effects of probenecid on the uptake of MeHg through the organic anion transport system. Different extracellular pH levels were used to examine effects on the uptake of MeHg and on probenecid induced effects on the uptake of MeHg through the organic anion transport system; the effects of three anisotonic conditions were also determined. The results showed: (1) probenecid might partially change the role of Na{sup +} ion from inhibition to stimulation for the uptake of MeHg; (2) the organic anion transport system for the uptake of MeHg was pH-dependent within the physiological range of extracellular pH; (3) the organic transport system for the uptake of MeHg was independent of deformation of the erythrocyte membrane. (orig.). With 4 figs.

  4. Mercury flow experiments. 4th report Measurements of erosion rate caused by mercury flow

    CERN Document Server

    Kinoshita, H; Hino, R; Kaminaga, M

    2002-01-01

    The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a construction plan of the Material-Life Science Facility, which is consisted of a Muon Science Facility and a Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutron generated by the spallation reaction of a 1 MW pulsed proton beam and mercury target. Design of the spallation mercury target system aims to obtain high neutron performance with high reliability and safety. Since the target system is using mercury as the target material and contains large amount of radioactive spallation products, it is necessary to estimate reliability for strength of instruments in a mercury flow system during lifetime of the facility. Piping and components in the mercury flow system would be damaged by erosion with mercury flow, since these components will be we...

  5. Virtualization in control system environment

    International Nuclear Information System (INIS)

    Shen, L.R.; Liu, D.K.; Wan, T.M.

    2012-01-01

    In large scale distributed control system, there are lots of common service composed an environment for the entire control system, such as the server system for the common software base library, application server, archive server and so on. This paper gives a description of a virtualization realization for control system environment including the virtualization for server, storage, network system and application for the control system. With a virtualization instance of the EPICS based control system environment that was built by the VMware vSphere v4, we tested the whole functionality of this virtualization environment in the SSRF control system, including the common server of the NFS, NIS, NTP, Boot and EPICS base and extension library tools, we also have applied virtualization to application servers such as the Archive, Alarm, EPICS gateway and all of the network based IOC. Specially, we test the high availability and VMotion for EPICS asynchronous IOC successful under the different VLAN configuration of the current SSRF control system network. (authors)

  6. Ocular disorders among workers exposed to mercury.

    Science.gov (United States)

    Gabal, M S; Raslan, O A

    1995-01-01

    Mercury vapor exposed workers may show ocular changes, as well as other systems affection. A sample of 84 workers in preparing mercury fulminate were examined for conjunctival corneal and lenticular manifestation of long duration exposure, together with mercury urinary output. Lens changes were found in 50% of the involved workers while keratopathy as recorded in 34.5% of them. No statistically significant association was found between the occurrence of eye lesions and levels of urinary elimination of mercury. These results suggest local absorption of this element is most probably the underlying cause of ocular affection.

  7. Metal-solid interactions controlling the bioavailability of mercury from sediments to clams and sipunculans.

    Science.gov (United States)

    Zhong, Huan; Wang, Wen-Xiong

    2006-06-15

    The bioavailability of sedimentary Hg(II) and methylmercury (MeHg) was quantified by measuring the assimilation efficiency (AE) in the clam Ruditapes philippinarum and the extraction of the gut juices from the sipunculan Sipunculus nudus. Three factors (Hg concentration in sediment, Hg sediment contact time, and organic content of sediments) were modified to examine metal-solid interactions in controlling Hg bioavailability. The Hg AEs in the clams were strongly correlated with the extraction from the sipunculan gut juices for both Hg species. The bioavailability of both Hg(II) and MeHg generally increased with increased sediment Hg concentration but decreased with sedimentmetal contact time and increasing organic content (except that MeHg was not influenced by organic content). Hg(II) speciation in sediments, quantified by sequential chemical extraction (SCE), was dependent on geochemical conditions and greatly controlled the mobility and bioavailability of Hg(II) in sediments. Most bioavailable Hg(II) originated from the strongly complexed phase (e.g., Hg bound up in Fe/Mn oxide, amorphous organosulfur, or mineral lattice), whereas Hg bound with the organocomplexed phase (Hg humic and Hg2Cl2) was not bioavailable. Hg bound with the other geochemical phases (water soluble, HgO, HgSO4, and HgS) contributed very little to the bioavailable Hg due to their low partitionings. Further, the amount of bioavailable Hg was inversely related to the particle reactivity of Hg with the sediments. Detailed analyses of metal-solid interactions provide a better understanding of how Hg in sediments can predict Hg concentration and therefore bioavailability in benthic invertebrates.

  8. Instrumentation and control system design

    International Nuclear Information System (INIS)

    Saito, Kenji; Sawahata, Hiroaki; Homma, Fumitaka; Kondo, Makoto; Mizushima, Toshihiko

    2004-01-01

    The instrumentation and control system of the high temperature engineering test reactor consists of the instrumentation, control equipments and safety protection systems. There are not many differences in the instrumentation and control equipments design between the HTTR and light water reactors except for some features. Various kinds of R and D of reactor instrumentation were performed taking into account the HTTR operational conditions, and a plant dynamic analysis was carried out considering the operational conditions of the HTTR in order to design the control system. These systems are required to have a high reliability in respect to safety. In the rise-to-power test it was confirmed that the instrumentation has a high reliability and the control system has a high stability and reasonable damped characteristics for various disturbances

  9. Optimal Control of Mechanical Systems

    Directory of Open Access Journals (Sweden)

    Vadim Azhmyakov

    2007-01-01

    Full Text Available In the present work, we consider a class of nonlinear optimal control problems, which can be called “optimal control problems in mechanics.” We deal with control systems whose dynamics can be described by a system of Euler-Lagrange or Hamilton equations. Using the variational structure of the solution of the corresponding boundary-value problems, we reduce the initial optimal control problem to an auxiliary problem of multiobjective programming. This technique makes it possible to apply some consistent numerical approximations of a multiobjective optimization problem to the initial optimal control problem. For solving the auxiliary problem, we propose an implementable numerical algorithm.

  10. Mercury contamination extraction

    Science.gov (United States)

    Fuhrmann, Mark [Silver Spring, MD; Heiser, John [Bayport, NY; Kalb, Paul [Wading River, NY

    2009-09-15

    Mercury is removed from contaminated waste by firstly applying a sulfur reagent to the waste. Mercury in the waste is then permitted to migrate to the reagent and is stabilized in a mercury sulfide compound. The stable compound may then be removed from the waste which itself remains in situ following mercury removal therefrom.

  11. Argonne's atlas control system upgrade

    International Nuclear Information System (INIS)

    Munson, F.; Quock, D.; Chapin, B.; Figueroa, J.

    1999-01-01

    The ATLAS facility (Argonne Tandem-Linac Accelerator System) is located at the Argonne National Laboratory. The facility is a tool used in nuclear and atomic physics research, which focuses primarily on heavy-ion physics. The accelerator as well as its control system are evolutionary in nature, and consequently, continue to advance. In 1998 the most recent project to upgrade the ATLAS control system was completed. This paper briefly reviews the upgrade, and summarizes the configuration and features of the resulting control system

  12. Decentralized control of complex systems

    CERN Document Server

    Siljak, Dragoslav D

    2011-01-01

    Complex systems require fast control action in response to local input, and perturbations dictate the use of decentralized information and control structures. This much-cited reference book explores the approaches to synthesizing control laws under decentralized information structure constraints.Starting with a graph-theoretic framework for structural modeling of complex systems, the text presents results related to robust stabilization via decentralized state feedback. Subsequent chapters explore optimization, output feedback, the manipulative power of graphs, overlapping decompositions and t

  13. RECOVERY OF MERCURY FROM CONTAMINATED LIQUID WASTES

    Energy Technology Data Exchange (ETDEWEB)

    Robin M. Stewart

    1999-09-29

    Mercury was widely used in U.S. Department of Energy (DOE) weapons facilities, resulting in a broad range of mercury-contaminated wastes and wastewaters. Some of the mercury contamination has escaped to the local environment, particularly at the Y-12 Plant in Oak Ridge, Tennessee, where approximately 330 metric tons of mercury were discharged to the environment between 1953 and 1963 (TN & Associates, 1998). Effective removal of mercury contamination from water is a complex and difficult problem. In particular, mercury treatment of natural waters is difficult because of the low regulatory standards. For example, the Environmental Protection Agency has established a national ambient water quality standard of 12 parts-per-trillion (ppt), whereas the standard is 1.8 ppt in the Great Lakes Region. In addition, mercury in the environment is typically present in several different forms, but sorption processes are rarely effective with more than one or two of these forms. To meet the low regulatory discharge limits, an effective sorption process must be able to address all forms of mercury present in the water. One approach is to apply different sorbents in series depending on the mercury speciation and the regulatory discharge limits. ADA Technologies, Inc. has developed four new sorbents to address the variety of mercury species present in industrial discharges and natural waters. Three of these sorbents have been field tested on contaminated creek water at the Y-12 Plant. Two of these sorbents have been successfully demonstrated very high removal efficiencies for soluble mercury species, reducing mercury concentrations at the outlet of a pilot-scale system to less than 12 ppt for as long as six months. The other sorbent tested at the Y-12 Plant targeted colloidal mercury not removed by standard sorption or filtration processes. At the Y-12 Plant, colloidal mercury appears to be associated with iron, so a sorbent that removes mercury-iron complexes in the presence of a

  14. Vacuum control system of VEC

    International Nuclear Information System (INIS)

    Roy, Anindya; Bhole, R.B.; Bandopadhyay, D.L.; Mukhopadhyay, B.; Pal, Sarbajit; Sarkar, D.

    2009-01-01

    As a part of modernization of VEC (Variable Energy Cyclotron), the Vacuum Control System is being upgraded to PLC based automated system from initial Relay based Manual system. EPICS (Experimental Physics and Industrial Control System), a standard open source software tool for designing distributed control system, is chosen for developing the supervisory control software layer, leading towards a unified distributed control architecture of VEC Control System. A Modbus - TCP based IOC (I/O Controller) has been developed to communicate control data to PLC using Ethernet-TCP LAN. Keeping in mind, the operators' familiarity with MS-Windows, a MS-Windows based operator interface is developed using VB6. It is also used to test and evaluate EPICS compatibility to MS Windows. Several MS Windows ActiveX components e.g. text display, image display, alarm window, set-point input etc. have been developed incorporating Channel Access library of EPICS. Use of such components ease the programming complexity and reduce developmental time of the operator interface. The system is in the final phase of commissioning. (author)

  15. [Oxidation of mercury by CuBr2 decomposition under controlled-release membrane catalysis condition].

    Science.gov (United States)

    Hu, Lin-Gang; Qu, Zan; Yan, Nai-Qiang; Guo, Yong-Fu; Xie, Jiang-Kun; Jia, Jin-Ping

    2014-02-01

    CuBr2 in the multi-porous ceramic membrane can release Br2 at high temperature, which was employed as the oxidant for Hg0 oxidation. Hg0 oxidation efficiency was studied by a membrane catalysis device. Meanwhile, a reaction and in situ monitoring device was designed to avoid the impact of Br2 on the downstream pipe. The result showed that the MnO(x)/alpha-Al2O3 catalysis membrane had a considerable "controlled-release" effect on Br2 produced by CuBr2 decomposition. The adsorption and reaction of Hg0 and Br2 on the surface of catalysis membrane obeyed the Langmuir-Hinshelwood mechanism. The removal efficiency of Hg0 increased with the rising of Br2 concentration. However, when Br2 reached a certain concentration, the removal efficiency was limited by adsorption rate and reaction rate of Hg0 and Br2 on the catalysis membrane. From 473 K to 573 K, the variation of Hg0 oxidation efficiency was relatively stable. SO2 in flue gas inhibited the oxidation of Hg0 while NO displayed no obvious effect.

  16. Mercury flow experiments. 4th report: Measurements of erosion rate caused by mercury flow

    International Nuclear Information System (INIS)

    Kinoshita, Hidetaka; Kaminaga, Masanori; Haga, Katsuhiro; Hino, Ryutaro

    2002-06-01

    The Japan Atomic Energy Research Institute (JAERI) and the High Energy Accelerator Research Organization (KEK) are promoting a construction plan of the Material-Life Science Facility, which is consisted of a Muon Science Facility and a Neutron Scattering Facility, in order to open up the new science fields. The Neutron Scattering Facility will be utilized for advanced fields of Material and Life science using high intensity neutron generated by the spallation reaction of a 1 MW pulsed proton beam and mercury target. Design of the spallation mercury target system aims to obtain high neutron performance with high reliability and safety. Since the target system is using mercury as the target material and contains large amount of radioactive spallation products, it is necessary to estimate reliability for strength of instruments in a mercury flow system during lifetime of the facility. Piping and components in the mercury flow system would be damaged by erosion with mercury flow, since these components will be weak by thickness decreasing. This report presents experimental results of wall thickness change by erosion using a mercury experimental loop. In the experiments, an erosion test section and coupons were installed in the mercury experimental loop, and their wall thickness was measured with an ultra sonic thickness gage after every 1000 hours. As a result, under 0.7 m/s of mercury velocity condition which is slightly higher than the practical velocity in mercury pipelines, the erosion is about 3 μm in 1000 hours. The wall thickness decrease during facility lifetime of 30 years is estimated to be less than 0.5 mm. According to the experimental result, it is confirmed that the effect of erosion on component strength is extremely small. Moreover, a measurement of residual mercury on the piping surface was carried out. As a result, 19 g/m 2 was obtained as the residual mercury for the piping surface. According to this result, estimated amount of residual mercury for

  17. Mercury, Vaccines, and Autism

    Science.gov (United States)

    Baker, Jeffrey P.

    2008-01-01

    The controversy regarding the once widely used mercury-containing preservative thimerosal in childhood vaccines has raised many historical questions that have not been adequately explored. Why was this preservative incorporated in the first place? Was there any real evidence that it caused harm? And how did thimerosal become linked in the public mind to the “autism epidemic”? I examine the origins of the thimerosal controversy and their legacy for the debate that has followed. More specifically, I explore the parallel histories of three factors that converged to create the crisis: vaccine preservatives, mercury poisoning, and autism. An understanding of this history provides important lessons for physicians and policymakers seeking to preserve the public’s trust in the nation’s vaccine system. PMID:18172138

  18. Spallation Neutron Source Accelerator Facility Target Safety and Non-safety Control Systems

    International Nuclear Information System (INIS)

    Battle, Ronald E.; DeVan, B.; Munro, John K. Jr.

    2006-01-01

    The Spallation Neutron Source (SNS) is a proton accelerator facility that generates neutrons for scientific researchers by spallation of neutrons from a mercury target. The SNS became operational on April 28, 2006, with first beam on target at approximately 200 W. The SNS accelerator, target, and conventional facilities controls are integrated by standardized hardware and software throughout the facility and were designed and fabricated to SNS conventions to ensure compatibility of systems with Experimental Physics Integrated Control System (EPICS). ControlLogix Programmable Logic Controllers (PLCs) interface to instruments and actuators, and EPICS performs the high-level integration of the PLCs such that all operator control can be accomplished from the Central Control room using EPICS graphical screens that pass process variables to and from the PLCs. Three active safety systems were designed to industry standards ISA S84.01 and IEEE 603 to meet the desired reliability for these safety systems. The safety systems protect facility workers and the environment from mercury vapor, mercury radiation, and proton beam radiation. The facility operators operated many of the systems prior to beam on target and developed the operating procedures. The safety and non-safety control systems were tested extensively prior to beam on target. This testing was crucial to identify wiring and software errors and failed components, the result of which was few problems during operation with beam on target. The SNS has continued beam on target since April to increase beam power, check out the scientific instruments, and continue testing the operation of facility subsystems

  19. JT-60 plasma control system

    International Nuclear Information System (INIS)

    Kurihara, K.

    1988-01-01

    JT-60 plasma control can be performed by the supervisory controller, the measurement system and actuators such as the poloidal field coil power supplies, gas injectors, neutral beam injection (NBI) heating system and radio frequency (RF) heating system. One of the most important characteristics of this system is a perfect digital control one composed of mini-computers, fast array processors and CAMAC modules, and it has large flexibility and few troubles to adjust the system. This system started to be operated in April 1985, after the six-year-long design, construction and testing, and have been operated and improved many times for two years. In this paper, the final system specification and its performance are presented aiming at the technological aspect of hardware and software. In addition, and experienced troubles are also presented. (author)

  20. Integrated Aeropropulsion Control System Design

    Science.gov (United States)

    Lin, C. -F.; Hurley, Francis X.; Huang, Jie; Hadaegh, F. Y.

    1996-01-01

    %T Integrated Aeropropulsion Control System Design%A C-F. Lin%A Francis X. Hurley%A Jie Huang%A F. Y. Hadaegh%J International Conference on Control and Information(psi)995%C Hong Kong%D June 1995%K aeropropulsion, control, system%U http://jpltrs.jpl.nasa.gov/1995/95-0658.pdfAn integrated intelligent control approach is proposed to design a high performance control system for aeropropulsion systems based on advanced sensor processing, nonlinear control and neural fuzzy control integration. Our approach features the following innovations:??e complexity and uncertainty issues are addressed via the distributed parallel processing, learning, and online reoptimization properties of neural networks.??e nonlinear dynamics and the severe coupling can be naturally incorporated into the design framework.??e knowledge base and decision making logic furnished by fuzzy systems leads to a human intelligence enhanced control scheme.In addition, fault tolerance, health monitoring and reconfigurable control strategies will be accommodated by this approach to ensure stability, graceful degradation and reoptimization in the case of failures, malfunctions and damage.!.

  1. Control of Solar Energy Systems

    CERN Document Server

    Camacho, Eduardo F; Rubio, Francisco R; Martínez, Diego

    2012-01-01

    Control of Solar Energy Systems details the main solar energy systems, problems involved with their control, and how control systems can help in increasing their efficiency.  After a brief introduction to the fundamental concepts associated with the use of solar energy in both photovoltaic and thermal plants, specific issues related to control of solar systems are embarked upon. Thermal energy systems are then explored in depth, as well as  other solar energy applications such as solar furnaces and solar refrigeration systems. Problems of variable generation profile and of the contribution of many solar plants to the same grid system are considered with the necessary integrated and supervisory control solutions being discussed. The text includes material on: ·         A comparison of basic and advanced control methods for parabolic troughs from PID to nonlinear model-based control; ·         solar towers and solar tracking; ·         heliostat calibration, characterization and off...

  2. Upgrading the ATLAS control system

    International Nuclear Information System (INIS)

    Munson, F.H.; Ferraretto, M.

    1993-01-01

    Heavy-ion accelerators are tools used in the research of nuclear and atomic physics. The ATLAS facility at the Argonne National Laboratory is one such tool. The ATLAS control system serves as the primary operator interface to the accelerator. A project to upgrade the control system is presently in progress. Since this is an upgrade project and not a new installation, it was imperative that the development work proceed without interference to normal operations. An additional criteria for the development work was that the writing of additional ''in-house'' software should be kept to a minimum. This paper briefly describes the control system being upgraded, and explains some of the reasons for the decision to upgrade the control system. Design considerations and goals for the new system are described, and the present status of the upgrade is discussed

  3. Control Evaluation Information System Savings

    Directory of Open Access Journals (Sweden)

    Eddy Sutedjo

    2011-05-01

    Full Text Available The purpose of this research is to evaluate the control of information system savings in the banking and to identify the weaknesses and problem happened in those saving systems. Research method used are book studies by collecting data and information needed and field studies by interview, observation, questioner, and checklist using COBIT method as a standard to assess the information system control of the company. The expected result about the evaluation result that show in the problem happened and recommendation given as the evaluation report and to give a view about the control done by the company. Conclusion took from this research that this banking company has met standards although some weaknesses still exists in the system.Index Terms - Control Information System, Savings

  4. UNEP Demonstrations of Mercury Emission Reduction at Two Coal-fired Power Plants in Russia

    Directory of Open Access Journals (Sweden)

    Jozewicz W.

    2013-04-01

    Full Text Available The United Nations Environment Programme (UNEP partnership area “Mercury releases from coal combustion” (The UNEP Coal Partnership has initiated demonstrations of mercury air emission reduction at two coal-fired power plants in Russia. The first project has modified the wet particulate matter (PM scrubber installed in Toliatti thermal plant to allow for addition of chemical reagents (oxidants into the closedloop liquid spray system. The addition of oxidant resulted in significant improvement of mercury capture from 20% total mercury removal (without the additive up to 60% removal (with the additive. It demonstrates the effectiveness of sorbent injection technologies in conjunction with an electrostatic precipitator (ESP. ESPs are installed at 60%, while wet PM scrubbers are installed at 30% of total coal-fired capacity in Russia. Thus, the two UNEP Coal Partnership projects address the majority of PM emission control configurations occurring in Russia.

  5. Cigarette weight control systems

    International Nuclear Information System (INIS)

    Powell, G.F.W.; Bolt, R.C.; Simmons, A.

    1980-01-01

    A system is described for monitoring the weight of a continuous wrapped rod of tobacco formed by a cigarette-making machine. A scanner unit can be used which passes beta-rays from a primary radiation source through the rod. The absorption is measured by comparison of the intensity at a detector on the opposite side of the rod with that at a detector facing another smaller source, the balance unit. This is pre-set so that when the rod weight is correct the detected intensities from the two sources will be equal. It is essential that the scanning station is kept clean otherwise the dust is included in the weight reading and the cigarettes manufactured would be underweight. This can be checked using an artificial cigarette of known weight as a calibration check. In this device a test circuit can be connected to the scanner head and this opens the shutter over the radioactive source when the test is initiated. A warning device is initiated if the reading is beyond predetermined limits and can be made to prevent operation of the cigarette machine if a satisfactory test is not obtained. (U.K.)

  6. Vehicle electrical system state controller

    Science.gov (United States)

    Bissontz, Jay E.

    2017-10-17

    A motor vehicle electrical power distribution system includes a plurality of distribution sub-systems, an electrical power storage sub-system and a plurality of switching devices for selective connection of elements of and loads on the power distribution system to the electrical power storage sub-system. A state transition initiator provides inputs to control system operation of switching devices to change the states of the power distribution system. The state transition initiator has a plurality of positions selection of which can initiate a state transition. The state transition initiator can emulate a four position rotary ignition switch. Fail safe power cutoff switches provide high voltage switching device protection.

  7. Estimated quantity of mercury in amalgam waste water residue released by dentists into the sewerage system in Ontario, Canada.

    Science.gov (United States)

    Adegbembo, Albert O; Watson, Philip A

    2004-12-01

    To estimate the quantity of dental amalgam that Ontario dentists release into waste water. Information from a self-administered postal survey of Ontario dentists was combined with the results of other experiments on the weight of amalgam restorations and the quantity of amalgam waste that bypasses solids separators in dental offices. Algorithms were developed to compute the quantity of amalgam waste leaving dental offices when dentists used or did not use ISO 11143 amalgam particle separators. A total of 878 (44.0%) of 1,994 sampled dentists responded to the survey. It was estimated that Ontario dentists removed 1,880.32 kg of amalgam (940.16 kg of mercury) during 2002, of which 1,128.19 kg of amalgam (564.10 kg of mercury) would have been released into waste water in Ontario if no dentists had been using a separator. Approximately 22% of the dentists reported using amalgam particle separators. On the basis of current use of amalgam separators, it was estimated that 861.78 kg of amalgam (430.89 kg of mercury or 170.72 mg per dentist daily) was released in 2002. The use of amalgam separators by all dentists could reduce the quantity of amalgam (and mercury) entering waste water to an estimated 12.41 kg (6.21 kg of mercury, or 2.46 mg per dentist per day). Amalgam particles separators can dramatically reduce amalgam and mercury loading in waste water released from dental offices.

  8. Manual control of unstable systems

    Science.gov (United States)

    Allen, R. W.; Hogue, J. R.; Parseghian, Z.

    1986-01-01

    Under certain operational regimes and failure modes, air and ground vehicles can present the human operator with a dynamically unstable or divergent control task. Research conducted over the last two decades has explored the ability of the human operator to control unstable systems under a variety of circumstances. Past research is reviewed and human operator control capabilities are summarized. A current example of automobile directional control under rear brake lockup conditions is also reviewed. A control system model analysis of the driver's steering control task is summarized, based on a generic driver/vehicle model presented at last year's Annual Manual. Results from closed course braking tests are presented that confirm the difficulty the average driver has in controlling the unstable directional dynamics arising from rear wheel lockup.

  9. Traction Control System for Motorcycles

    Directory of Open Access Journals (Sweden)

    Cardinale Pascal

    2009-01-01

    Full Text Available Traction control is a widely used control system to increase stability and safety of four wheel vehicles. Automatic stability control is used in the BMW K1200R motorcycle and in motoGP competition, but not in other motorcycles. This paper presents an algorithm and a low-cost real-time hardware implementation for motorcycles. A prototype has been developed, applied on a commercial motorcycle, and tested in a real track. The control system that can be tuned by the driver during the race has been appreciated by the test driver.

  10. ISABELLE control system: design concepts

    International Nuclear Information System (INIS)

    Humphrey, J.W.

    1979-01-01

    ISABELLE is a Department of Energy funded proton accelerator/storage ring being built at Brookhaven National Laboratory (Upton, Long Island, New York). It is large (3.8 km circumference) and complicated (approx. 30,000 monitor and control variables). It is based on superconducting technology. Following the example of previous accelerators, ISABELLE will be operated from a single control center. The control system will be distributed and will incorporate a local computer network. An overview of the conceptual design of the ISABELLE control system will be presented

  11. A Novel Combination of Methods Developed for Decision Support on Abatement of Mercury in Europe

    Directory of Open Access Journals (Sweden)

    Sundseth K.

    2013-04-01

    Full Text Available There is clear evidence from the global mercury cycle that there is an urgent need for actions to reduce global anthropogenic mercury emissions. A legally- binding global agreement to reduce emissions of mercury is soon in place, meaning that many countries need to take steps to lower their emissions. Identification and assessment of policy options that already are in place as well as setting pollution control objectives and developing effective strategies to meet these objectives, are depending on a decision support tool that allows for identifying current and future environmental problems and to reduce these problems by providing a holistic management approach. Recent scientific advancement allows a more complete picture of the mercury problems and solutions to the problems, which is of outmost interest when it comes to justifying spending resources on the relevant measures. To make sure that resource allocation is favoring human welfare, the economic costs of introducing these measures need to be compared to their economic benefits. The major goal of this study was to provide a novel combination of assessment tools that form a framework for a decision support system towards environmental policy on mercury in Europe. The decision support tool was intended to act as a guideline for policy makers for the purpose of introducing cost- effective abatement of mercury. It was for the EU 27 countries demonstrated that large economic benefits can be achieved globally with reduced mercury emissions in the EU region. The investigated Baseline scenario thus highlighted the importance of full implementation of existing measures and the importance of making further progress in reducing mercury emissions from European sources. Reducing emissions in developing countries may however, be more cost effective, which basically reconfirms the need for a global convention on mercury.

  12. Test results of HTTR control system

    International Nuclear Information System (INIS)

    Motegi, Toshihiro; Iigaki, Kazuhiko; Saito, Kenji; Sawahata, Hiroaki; Hirato, Yoji; Kondo, Makoto; Shibutani, Hideki; Ogawa, Satoru; Shinozaki, Masayuki; Mizushima, Toshihiko; Kawasaki, Kozo

    2006-06-01

    The plant control performance of the IHX helium flow rate control system, the PPWC helium flow rate control system, the secondary helium flow rate control system, the inlet temperature control system, the reactor power control system and the outlet temperature control system of the HTTR are obtained through function tests and power-up tests. As the test results, the control systems show stable control response under transient condition. Both of inlet temperature control system and reactor power control system shows stable operation from 30% to 100%, respectively. This report describes the outline of control systems and test results. (author)

  13. Mercury removal sorbents

    Science.gov (United States)

    Alptekin, Gokhan

    2016-03-29

    Sorbents and methods of using them for removing mercury from flue gases over a wide range of temperatures are disclosed. Sorbent materials of this invention comprise oxy- or hydroxyl-halogen (chlorides and bromides) of manganese, copper and calcium as the active phase for Hg.sup.0 oxidation, and are dispersed on a high surface porous supports. In addition to the powder activated carbons (PACs), this support material can be comprised of commercial ceramic supports such as silica (SiO.sub.2), alumina (Al.sub.2O.sub.3), zeolites and clays. The support material may also comprise of oxides of various metals such as iron, manganese, and calcium. The non-carbon sorbents of the invention can be easily injected into the flue gas and recovered in the Particulate Control Device (PCD) along with the fly ash without altering the properties of the by-product fly ash enabling its use as a cement additive. Sorbent materials of this invention effectively remove both elemental and oxidized forms of mercury from flue gases and can be used at elevated temperatures. The sorbent combines an oxidation catalyst and a sorbent in the same particle to both oxidize the mercury and then immobilize it.

  14. Mercury Quick Facts: Health Effects of Mercury Exposure

    Science.gov (United States)

    Mercury Quick Facts Health Effects of Mercury Exposure What is Elemental Mercury? Elemental (metallic) mercury is the shiny, silver-gray metal found in thermometers, barometers, and thermostats and other ...

  15. Surface-air mercury fluxes across Western North America: A synthesis of spatial trends and controlling variables

    International Nuclear Information System (INIS)

    Eckley, Chris S.; Tate, Mike T.; Lin, Che-Jen; Gustin, Mae; Dent, Stephen; Eagles-Smith, Collin; Lutz, Michelle A.; Wickland, Kimberly P.; Wang, Bronwen; Gray, John E.; Edwards, Grant C.; Krabbenhoft, Dave P.; Smith, David B.

    2016-01-01

    Mercury (Hg) emission and deposition can occur to and from soils, and are an important component of the global atmospheric Hg budget. This paper focuses on synthesizing existing surface-air Hg flux data collected throughout the Western North American region and is part of a series of geographically focused Hg synthesis projects. A database of existing Hg flux data collected using the dynamic flux chamber (DFC) approach from almost a thousand locations was created for the Western North America region. Statistical analysis was performed on the data to identify the important variables controlling Hg fluxes and to allow spatiotemporal scaling. The results indicated that most of the variability in soil-air Hg fluxes could be explained by variations in soil-Hg concentrations, solar radiation, and soil moisture. This analysis also identified that variations in DFC methodological approaches were detectable among the field studies, with the chamber material and sampling flushing flow rate influencing the magnitude of calculated emissions. The spatiotemporal scaling of soil-air Hg fluxes identified that the largest emissions occurred from irrigated agricultural landscapes in California. Vegetation was shown to have a large impact on surface-air Hg fluxes due to both a reduction in solar radiation reaching the soil as well as from direct uptake of Hg in foliage. Despite high soil Hg emissions from some forested and other heavily vegetated regions, the net ecosystem flux (soil flux + vegetation uptake) was low. Conversely, sparsely vegetated regions showed larger net ecosystem emissions, which were similar in magnitude to atmospheric Hg deposition (except for the Mediterranean California region where soil emissions were higher). The net ecosystem flux results highlight the important role of landscape characteristics in effecting the balance between Hg sequestration and (re-)emission to the atmosphere. - Highlights: • Soil-air Hg fluxes are an important component of the

  16. Mussel tissue (T-31) - A new analytical quality control material for the determination of mercury and arsenic in mussels

    Energy Technology Data Exchange (ETDEWEB)

    Gawlik, B. [Joint Research Centre Ispra, Ispra, Varese (Italy). Environment Institute]|[Muenchen, Technische Universitaet (Germany). Lehrstuhl fuer Oekologische Chemie und Umweltanalytik; Druges, M. [Thomson Microelectronics, Crolles (France); Bianchi, M.; Muntau, H. [Joint Research Centre Ispra, Ispra, Varese (Italy). Environment Institute; Bortoli, A. [ULSS 12, Venice (Italy). Presidio Multizonale di Prevenzione; Kettrup, A. [Muenchen, Technische Universitaet (Germany). Lehrstuhl fur Oekologische Chemie und Umweltanalytik]|[GSF Forschungszentrum fuer Umwelt und Gesundheit, Oberschleissheim (Germany). Inst. fuer Oekologische Chemie

    1998-05-01

    The use of filter-feeding molluscs for the monitoring of selected contaminant levels in the marine environment is well-known in the scientific community. In the order to assure the quality of those analysis and to prepare laboratories for accreditation procedures certified reference materials and proficiency testing campaigns were introduced. However, there is still a need for the introduction of suitable analytical quality materials of high quality which can be used on a daily basis. This paper therefore describes the preparation of a mussel tissue material for the internal quality control of Hg and As analysis in bivalves, as well as the principle of preparation and the analytical characterisation of such a material. The total concentration for arsenic (8.98 {+-} 0.67 {mu}g/g) and mercury (0.169 {+-} 0.005 {mu}g/g) was determined by the use of different techniques. Additionally, indicative values for major constituents (C, H, N, Na, Cl, P, S, K, Mg, Ca, Si, Fe, Al, Br, Zn, Sr) and some trace elements (Cu, Cd, Pb, Ni) were measured. [Italiano] L`uso di molluschi filtratori nel monitoraggio dei livelli di contaminazione in ambiente marino e` ben noto in ambito scientifico. Per assicurare la qualita` di queste analisi e preparare i laboratori alle procedure di accreditamento e stato introdotto l`uso di materiali di riferimento certificati accoppiato alla partecipazione a campagne di controllo interlaboratoriale. Attualmente non sono ancora disponibili materiali di riferimento appropriati e di alta qualita`, che possano essere usati su base quotidiana. Questo lavoro descrive la preparazione di un materiale di riferimanto di cozze da usare come mezzo di controllo di qualita` interna e i principi di preparazione e di caratterizzazione analitica di un materiale di questo tipo. La concentrazione totale dell`arsenico (8.98 {+-} 0.67 {mu}g/g) e del mercurio (0.169 {+-} 0.005 {mu}g/g) sono state determinati mediante l`uso di differenti tecniche. Sono stati in oltre misurati

  17. Surface-air mercury fluxes across Western North America: A synthesis of spatial trends and controlling variables

    Energy Technology Data Exchange (ETDEWEB)

    Eckley, Chris S., E-mail: eckley.chris@epa.gov [US Environmental Protection Agency, Region-10, Seattle, WA 98101 (United States); Tate, Mike T. [US Geological Survey, Middleton, WI 53562 (United States); Lin, Che-Jen [Center for Advances on Water and Air quality, Lamar University, Beaumont, TX 77710 (United States); Gustin, Mae [Department of Natural Resources & Environmental Science, University of Nevada, Reno, NV 89557 (United States); Dent, Stephen [CDM Smith, Portland, OR 97205 (United States); Eagles-Smith, Collin [US Geological Survey, Corvallis, OR 97331 (United States); Lutz, Michelle A. [US Geological Survey, Middleton, WI 53562 (United States); Wickland, Kimberly P. [US Geological Survey Boulder, CO 80303 (United States); Wang, Bronwen [US Geological Survey, Anchorage, AK 99508 (United States); Gray, John E. [US Geological Survey, Denver, CO 80225 (United States); Edwards, Grant C. [Department of Environment and Geography, Macquarie University, North Ryde, NSW 2109 (Australia); Krabbenhoft, Dave P. [US Geological Survey, Middleton, WI 53562 (United States); Smith, David B. [US Geological Survey, Denver, CO 80225 (United States)

    2016-10-15

    Mercury (Hg) emission and deposition can occur to and from soils, and are an important component of the global atmospheric Hg budget. This paper focuses on synthesizing existing surface-air Hg flux data collected throughout the Western North American region and is part of a series of geographically focused Hg synthesis projects. A database of existing Hg flux data collected using the dynamic flux chamber (DFC) approach from almost a thousand locations was created for the Western North America region. Statistical analysis was performed on the data to identify the important variables controlling Hg fluxes and to allow spatiotemporal scaling. The results indicated that most of the variability in soil-air Hg fluxes could be explained by variations in soil-Hg concentrations, solar radiation, and soil moisture. This analysis also identified that variations in DFC methodological approaches were detectable among the field studies, with the chamber material and sampling flushing flow rate influencing the magnitude of calculated emissions. The spatiotemporal scaling of soil-air Hg fluxes identified that the largest emissions occurred from irrigated agricultural landscapes in California. Vegetation was shown to have a large impact on surface-air Hg fluxes due to both a reduction in solar radiation reaching the soil as well as from direct uptake of Hg in foliage. Despite high soil Hg emissions from some forested and other heavily vegetated regions, the net ecosystem flux (soil flux + vegetation uptake) was low. Conversely, sparsely vegetated regions showed larger net ecosystem emissions, which were similar in magnitude to atmospheric Hg deposition (except for the Mediterranean California region where soil emissions were higher). The net ecosystem flux results highlight the important role of landscape characteristics in effecting the balance between Hg sequestration and (re-)emission to the atmosphere. - Highlights: • Soil-air Hg fluxes are an important component of the

  18. Landscape controls on total and methyl mercury in the upper Hudson River basin of New York State

    Science.gov (United States)

    Burns, D. A.; Murray, K. R.; Bradley, P. M.; Brigham, M. E.; Aiken, G.; Smith, M.

    2010-12-01

    High levels of mercury (Hg) in aquatic biota have been identified in surface waters of the Adirondack region of New York, and factors such as the prevalence of wetlands, extensive forest cover, and oligotrophic waters promote Hg bioaccumulation in this region. Past research in this region has focused on improved understanding of the Hg cycle in lake ecosystems. In the study described herein, the landscape controls on total Hg and methylmercury (MeHg) concentrations in riverine ecosystems were explored through synoptic surveys of 27 sites in the upper Hudson River basin of the Adirondack region. Stream samples were collected and analyzed for total Hg, MeHg, dissolved organic carbon (DOC), and ultraviolet absorbance at 254 nm (UV254) during spring and summer of 2006-08. Landscape indices including many common land cover, hydrographic, and topographic-based measures were explored as predictors of Hg through multivariate linear regression. Multivariate models that included a wetland or riparian area-based metric, an index for open water area, and in some cases a topographic metric such as the wetness index explained 55 to 65 percent of the variation in MeHg concentrations, and 55 to 80 percent of the variation in total Hg concentrations. An open water index (OWI) was developed that incorporated both the basin area drained by ponded water and the surface area of these ponds. This index was inversely related to concentrations of total Hg and MeHg. This OWI was also inversely related to specific ultra-violet absorbance, consistent with previous studies showing that open water increases the influence of algal-derived carbon on DOC, decreasing aromaticity, which should decrease the ability of the dissolved carbon pool to bind Hg. The OWI was not significant in models for total Hg that also included UV254 as a predictive variable, but the index did remain significant in similar models for MeHg suggesting that biogeochemical factors in addition to decreasing carbon

  19. Novel methodology for the study of mercury methylation and reduction in sediments and water using 197Hg radiotracer

    International Nuclear Information System (INIS)

    Ribeiro Guevara, Sergio; Perez Catan, Soledad; Zizek, Suzana; Repinc, Urska; Jacimovic, Radojko; Horvat, Milena

    2007-01-01

    Mercury tracers are powerful tools that can be used to study mercury transformations in environmental systems, particularly mercury methylation, demethylation and reduction in sediments and water. However, mercury transformation studies using tracers can be subject to error, especially when used to assess methylation potential. The organic mercury extracted can be as low as 0.01% of the endogenous labeled mercury, and artefacts and contamination present during methylmercury (MeHg) extraction processes can cause interference. Solvent extraction methods based on the use of either KBr/H 2 SO 4 or HCl were evaluated in freshwater sediments using 197 Hg radiotracer. Values obtained for the 197 Hg tracer in the organic phase were up to 25-fold higher when HCl was used, which is due to the coextraction of 197 Hg 2+ into the organic phase during MeHg extraction. Evaluations of the production of MeHg gave similar results with both MeHg extraction procedures, but due to the higher Hg 2+ contamination of the controls, the uncertainty in the determination was higher when HCl was used. The Hg 2+ contamination of controls in the HCl extraction method showed a nonlinear correlation with the humic acid content of sediment pore water. Therefore, use of the KBr/H 2 SO 4 method is recommended, since it is free from these interferences. 197 Hg radiotracer (T 1/2 = 2.673 d) has a production rate that is about 50 times higher than that of 203 Hg (T 1/2 46.595 d), the most frequently used mercury radiotracer. Hence it is possible to obtain a similar level of performance to 203 Hg when it is used it in short-term experiments and produced by the irradiation of 196 Hg with thermal neutrons, using mercury targets with the natural isotopic composition. However, if the 0.15% natural abundance of the 196 Hg isotope is increased, the specific activity of the 197 Hg tracer can be significantly improved. In the present work, 197 Hg tracer was produced from mercury 51.58% enriched in the 196 Hg

  20. Methymercury Formation in Marine and Freshwater Systems: Sediment Characteristics, Microbial Activity and SRB Phylogeny Control Formation Rates and Food-Chain Exposure

    Science.gov (United States)

    King, J. K.; Saunders, F. M.

    2004-05-01

    Mercury research in freshwater and marine systems suggests that sediment characteristics such as organic substrate, mercury speciation, and sulfate/sulfide concentrations influence availability of inorganic mercury for methylation. Similarly, sediment characteristics also influence sulfate-reducing bacterial (SRB) respiration as well as the presence/distribution of phylogenetic groups responsible for mercury methylation. Our work illustrates that the process of methylmercury formation in freshwater and marine systems are not dissimilar. Rather, the same geochemical parameters and SRB phylogenetic groups determine the propensity for methylmercury formation and are applicable in both fresh- and marine-water systems. The presentation will include our integration of sediment geochemical and microbial parameters affecting mercury methylation in specific freshwater and marine systems. Constructed wetlands planted with Schoenoplectus californicus and amended with gypsum (CaSO4) have demonstrated a capacity to remove inorganic mercury from industrial outfalls. However, bioaccumulation studies of periphyton, eastern mosquitofish (Gambusia holbrooki) and lake chubsucker (Erimyzon sucetta) were conducted in order to ascertain the availability of wetland-generated methylmercury to biota. Total mercury concentrations in mosquitofish from non-sulfate treated controls and the reference location were significantly lower than those from the low and high sulfate treatments while mean total mercury concentrations in lake chubsuckers were also significantly elevated in the high sulfate treatment compared to the low sulfate, control and reference populations. Methylmercury concentrations in periphyton also corresponded with mercury levels found in the tissue of the lake chubsuckers, and these findings fit well given the trophic levels identified for both species of fish. Overall, data from this study suggest that the initial use of gypsum to accelerate the maturity of a constructed

  1. Increased Mercury Bioaccumulation Follows Water Quality Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Bogle, M.A.; Peterson, M.J.; Smith, J.G.; Southworth, G.R.

    1999-09-15

    Changes in physical and chemical characteristics of aquatic habitats made to reduce or eliminate ecological risks can sometimes have unforeseen consequences. Environmental management activities on the U.S. Dept. of Energy reservation in Oak Ridge, Tennessee,have succeeded in improving water quality in streams impacted by discharges fi-om industrial facilities and waste disposal sites. The diversity and abundance of pollution-sensitive components of the benthic macroinvertebrate communities of three streams improved after new waste treatment systems or remedial actions reduced inputs of various toxic chemicals. Two of the streams were known to be mercury-contaminated from historical spills and waste disposal practices. Waterborne mercury concentrations in the third were typical of uncontaminated systems. In each case, concentrations of mercury in fish, or the apparent biological availability of mercury increased over the period during which ecological metrics indicated improved water quality. In the system where waterborne mercury concentrations were at background levels, increased mercury bioaccumulation was probably a result of reduced aqueous selenium concentrations; however, the mechanisms for increased mercury accumulation in the other two streams remain under investigation. In each of the three systems, reduced inputs of metals and inorganic anions was followed by improvements in the health of aquatic invertebrate communities. However, this reduction in risk to aquatic invertebrates was accompanied by increased risk to humans and piscivorous wildlife related to increased mercury concentrations in fish.

  2. Increased Mercury Bioaccumulation Follows Water Quality Improvement

    International Nuclear Information System (INIS)

    Bogle, M.A.; Peterson, M.J.; Smith, J.G.; Southworth, G.R.

    1999-01-01

    Changes in physical and chemical characteristics of aquatic habitats made to reduce or eliminate ecological risks can sometimes have unforeseen consequences. Environmental management activities on the U.S. Dept. of Energy reservation in Oak Ridge, Tennessee,have succeeded in improving water quality in streams impacted by discharges fi-om industrial facilities and waste disposal sites. The diversity and abundance of pollution-sensitive components of the benthic macroinvertebrate communities of three streams improved after new waste treatment systems or remedial actions reduced inputs of various toxic chemicals. Two of the streams were known to be mercury-contaminated from historical spills and waste disposal practices. Waterborne mercury concentrations in the third were typical of uncontaminated systems. In each case, concentrations of mercury in fish, or the apparent biological availability of mercury increased over the period during which ecological metrics indicated improved water quality. In the system where waterborne mercury concentrations were at background levels, increased mercury bioaccumulation was probably a result of reduced aqueous selenium concentrations; however, the mechanisms for increased mercury accumulation in the other two streams remain under investigation. In each of the three systems, reduced inputs of metals and inorganic anions was followed by improvements in the health of aquatic invertebrate communities. However, this reduction in risk to aquatic invertebrates was accompanied by increased risk to humans and piscivorous wildlife related to increased mercury concentrations in fish

  3. Pneumonitis after Inhalation of Mercury Vapours

    Directory of Open Access Journals (Sweden)

    JD Glezos

    2006-01-01

    Full Text Available A 43-year-old man presented to hospital with pneumonia but only after discharge from hospital did he admit to deliberate prior inhalation of mercury. His pulmonary involvement appeared to resolve almost completely with antibiotics and supportive care. Nevertheless, persisting elevated urinary excretion of mercury required two courses of chelation therapy. No serious systemic sequelae were observed.

  4. The BATES linac control system

    International Nuclear Information System (INIS)

    Russ, T.; Radouch, Z.

    1989-01-01

    The Bates linac control system (LCS), a distributed processing architecture, is described. Due to the historic evolution of the system, a mix of different hardware, operating systems and programming languages are used throughout. However, a standardized interface at the network level enables a smooth system integration. In particular, a multicasting scheme for data transmission over the network permits simultaneous database updates on more than one workstation. This allows for true distribution of data processing power. 3 figs

  5. Interior Temperature Measurement Using Curved Mercury Capillary Sensor Based on X-ray Radiography

    Science.gov (United States)

    Chen, Shuyue; Jiang, Xing; Lu, Guirong

    2017-07-01

    A method was presented for measuring the interior temperature of objects using a curved mercury capillary sensor based on X-ray radiography. The sensor is composed of a mercury bubble, a capillary and a fixed support. X-ray digital radiography was employed to capture image of the mercury column in the capillary, and a temperature control system was designed for the sensor calibration. We adopted livewire algorithms and mathematical morphology to calculate the mercury length. A measurement model relating mercury length to temperature was established, and the measurement uncertainty associated with the mercury column length and the linear model fitted by least-square method were analyzed. To verify the system, the interior temperature measurement of an autoclave, which is totally closed, was taken from 29.53°C to 67.34°C. The experiment results show that the response of the system is approximately linear with an uncertainty of maximum 0.79°C. This technique provides a new approach to measure interior temperature of objects.

  6. Packaging of control system software

    International Nuclear Information System (INIS)

    Zagar, K.; Kobal, M.; Saje, N.; Zagar, A.; Sabjan, R.; Di Maio, F.; Stepanov, D.

    2012-01-01

    Control system software consists of several parts - the core of the control system, drivers for integration of devices, configuration for user interfaces, alarm system, etc. Once the software is developed and configured, it must be installed to computers where it runs. Usually, it is installed on an operating system whose services it needs, and also in some cases dynamically links with the libraries it provides. Operating system can be quite complex itself - for example, a typical Linux distribution consists of several thousand packages. To manage this complexity, we have decided to rely on Red Hat Package Management system (RPM) to package control system software, and also ensure it is properly installed (i.e., that dependencies are also installed, and that scripts are run after installation if any additional actions need to be performed). As dozens of RPM packages need to be prepared, we are reducing the amount of effort and improving consistency between packages through a Maven-based infrastructure that assists in packaging (e.g., automated generation of RPM SPEC files, including automated identification of dependencies). So far, we have used it to package EPICS, Control System Studio (CSS) and several device drivers. We perform extensive testing on Red Hat Enterprise Linux 5.5, but we have also verified that packaging works on CentOS and Scientific Linux. In this article, we describe in greater detail the systematic system of packaging we are using, and its particular application for the ITER CODAC Core System. (authors)

  7. Next Generation Target Control System

    National Research Council Canada - National Science Library

    1995-01-01

    Our objective was to evaluate the allegations concerning the Next Generation Target Control System Program and to determine whether the Program is the most cost effective solution to meet the target...

  8. VA National Bed Control System

    Data.gov (United States)

    Department of Veterans Affairs — The VA National Bed Control System records the levels of operating, unavailable and authorized beds at each VAMC, and it tracks requests for changes in these levels....

  9. Mercury recycling in the United States in 2000

    Science.gov (United States)

    Brooks, William E.; Matos, Grecia R.

    2005-01-01

    mercury is estimated because it is a low-volume commodity and its production, use, and disposal is difficult to track. The prices and volumes of each category of mercury-containing material may change dramatically from year to year. For example, the average price of mercury was approximately $150 per flask from 2000 until 2003 and then rose sharply to $650 per flask in fall 2004 and approximately $850 per flask in spring 2005. Since 1927, the common unit for measuring and pricing mercury has been the flask in order to conform to the system used at Almaden, Spain (Meyers, 1951). One flask weighs 34.5 kilograms, and 29 flasks of mercury are contained in a metric ton. In the United States, the chlorine-caustic soda industry, which is the leading end-user of elemental mercury, recycles most of its mercury in-plant as home scrap. Annual purchases of replacement mercury by the chlorine-caustic soda industry indicate that some mercury may be lost through evaporation to the environment, put into a landfill as industrial waste, or trapped within pipes in the plant. Impending closure of domestic and foreign mercury-cell chlorine-caustic soda plants and the shift to nonmercury technology for chlorine-caustic soda production could ultimately result in a significant volume of elemental mercury for recycling, sale, or storage. Globally, mercury is widely used in artisanal, or small-scale, gold mining. Most of that mercury is lost to the environment and is not recycled. The recycling rate for mercury was not available owing to insufficient data in 2000, and the efficiency of mercury recycling was estimated to be 62 percent.

  10. Integrated control system and method

    Science.gov (United States)

    Wang, Paul Sai Keat; Baldwin, Darryl; Kim, Myoungjin

    2013-10-29

    An integrated control system for use with an engine connected to a generator providing electrical power to a switchgear is disclosed. The engine receives gas produced by a gasifier. The control system includes an electronic controller associated with the gasifier, engine, generator, and switchgear. A gas flow sensor monitors a gas flow from the gasifier to the engine through an engine gas control valve and provides a gas flow signal to the electronic controller. A gas oversupply sensor monitors a gas oversupply from the gasifier and provides an oversupply signal indicative of gas not provided to the engine. A power output sensor monitors a power output of the switchgear and provide a power output signal. The electronic controller changes gas production of the gasifier and the power output rating of the switchgear based on the gas flow signal, the oversupply signal, and the power output signal.

  11. The ILC global control system

    International Nuclear Information System (INIS)

    Carwardine, J.; Arnold, N.; Lenkszus, F.; Saunders, C.; Rehlich, K.; Simrock, S.; Banerjee, B.; Chase, B.; Gottschalk, E.; Joireman, P.; Kasley, P.; Lackey, S.; McBride, P.; Pavlicek, V.; Patrick, J.; Votava, M.; Wolbers, S.; Furukawa, K.; Michizono, S.; Larsen, R.S.; Downing, R.

    2008-01-01

    The scale and performance parameters of the ILC require new thinking in regards to control system design. This design work has begun quite early in comparison to most accelerator projects, with the goal of uniquely high overall accelerator availability. Among the design challenges are high control system availability, precision timing and rf phase reference distribution, standardizing of interfaces, operability, and maintainability. We present the current state of the design and take a prospective look at ongoing research and development projects.

  12. Nova target diagnostics control system

    International Nuclear Information System (INIS)

    Severyn, J.R.

    1985-01-01

    During the past year the Nova target diagnostics control system was finished and put in service. The diagnostics loft constructed to the north of the target room provides the environmental conditions required to collect reliable target diagnostic data. These improvements include equipment cooling and isolation of the power source with strict control of instrumentation grounds to eliminate data corruption due to electromagnetic pulses from the laser power-conditioning system or from target implosion effects

  13. Control system oriented human interface

    International Nuclear Information System (INIS)

    Barale, P.; Jacobson, V.; Kilgore, R.; Rondeau, D.

    1976-11-01

    The on-line control system interface for magnet beam steering and focusing in the Bevalac is described. An Aydin model 5205B display generator was chosen. This display generator will allow the computer to completely rewrite a monitor screen in less than 50 ms and is also capable of controlling a color monitor

  14. NPL superconducting Linac control system

    International Nuclear Information System (INIS)

    Swanson, H.E.; Howe, M.A.; Jackson, L.W.; LaCroix, J.M.; Readdy, H.P.; Storm, D.W.; Van Houten, L.P.

    1985-01-01

    The control system for the NPL Linac is based on a Microvax II host computer connected in a star network with 9 satellite computers. These satellites use single board varsions of DEC's PDP 11 processor. The operator's console uses high performance graphics and touch screen technology to display the current linac status and as the means for interactively controlling the operation of the accelerator

  15. Contamination Control: a systems approach

    NARCIS (Netherlands)

    Donck, J.C.J. van der

    2010-01-01

    Contamination influences a wide variety of industrial processes. For complex systems, contamination control, the collective effort to control contamination to such a level that it guarantees or even improves process or product functionality, offers a way for finding workable solutions. Central in

  16. A novel microsatellite control system

    Energy Technology Data Exchange (ETDEWEB)

    Moore, K.R.; Frigo, J.R.; Tilden, M.W.

    1998-02-01

    The authors are researching extremely simple yet quite capable analog pulse-coded neural networks for ``smaller-faster-cheaper`` spacecraft attitude and control systems. The will demonstrate a prototype microsatellite that uses their novel control method to autonomously stabilize itself in the ambient magnetic field and point itself at the brightest available light source. Though still in design infancy, the ``Nervous Net`` controllers described could allow for space missions not currently possible given conventional satellite hardware. Result, prospects and details are presented.

  17. Robust power system frequency control

    CERN Document Server

    Bevrani, Hassan

    2014-01-01

    This updated edition of the industry standard reference on power system frequency control provides practical, systematic and flexible algorithms for regulating load frequency, offering new solutions to the technical challenges introduced by the escalating role of distributed generation and renewable energy sources in smart electric grids. The author emphasizes the physical constraints and practical engineering issues related to frequency in a deregulated environment, while fostering a conceptual understanding of frequency regulation and robust control techniques. The resulting control strategi

  18. Transport and accumulation of cesium-137 and mercury in the Clinch River and Watts Bar Reservoir system

    International Nuclear Information System (INIS)

    Olsen, C.R.; Larsen, I.L.; Lowry, P.D.; Moriones, C.R.; Ford, C.J.; Dearstone, K.C.; Turner, R.R.; Kimmel, B.L.; Brandt, C.C.

    1992-06-01

    Operations and waste disposal activities at the Oak Ridge Y-12 Plant, the Oak Ridge National Laboratory (ORNL), and the Oak Ridge K-25 Site (formerly the Oak Ridge Gaseous Diffusion Plant) on the US Department of Energy (DOE) Oak Ridge Reservation (ORR) have introduced a variety of airborne, liquid, and solid wastes into the surrounding environment. Some of these wastes may affect off-site areas by entering local streams, which ultimately drain into the Clinch and Tennessee river system. Previously reported concentrations of radionuclides, metals and organic compounds in water, sediment, and biota of the Clinch River and Watts Bar Reservoir suggest the presence of a variety of contaminants of possible concern to the protection of human health and the environment. The work reported here represents part of the initial scoping phase for the Clinch River RCRA Facility Investigation. In this work, the distribution of 137 Cs is used to identify contaminant accumulation patterns and potential problem, or ''hot-spot,'' areas with regard to environmental hazard or human health. Radiocesium was chosen for this scoping effort because (1) its history of release into the Clinch River is reasonably well documented, (2) it is easy and inexpensive to measure by gamma spectrometry, and (3) it is rapidly sorbed to particulate matter and thus serves as a cost-effective tracer for identifying the transport and accumulation patterns of many other particle-reactive contaminants, such as mercury (Hg), lead (Pb), and plutonium (Pu), and polychlorinated biphenyls (PCBs)

  19. Mercury Exposure among Garbage Workers in Southern Thailand.

    Science.gov (United States)

    Decharat, Somsiri

    2012-12-01

    1) To determine mercury levels in urine samples from garbage workers in Southern Thailand, and 2) to describe the association between work characteristics, work positions, behavioral factors, and acute symptoms; and levels of mercury in urine samples. A case-control study was conducted by interviewing 60 workers in 5 hazardous-waste-management factories, and 60 matched non-exposed persons living in the same area of Southern Thailand. Urine samples were collected to determine mercury levels by cold-vapor atomic absorption spectrometer mercury analyzer. The hazardous-waste workers' urinary mercury levels (10.07 µg/g creatinine) were significantly higher than the control group (1.33 µg/g creatinine) (p garbage workers' hygiene habits can reduce urinary mercury levels. Personal hygiene is important, and should be stressed in education programs. Employers should institute engineering controls to reduce urinary mercury levels among garbage workers.

  20. Applicability of the Mercury Controlled Volatilization Technique in the Cerco Minero de Almadenejos; Aplicabilidad de Tecnicas de Volatilizacion Controlada de Mercurio en el Cerco Minero de Almadenejos

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, L.; Sierra, M. J.; Millan, R.

    2013-02-01

    This work study the case of the Cerco Minero de Almadenejos (Ciudad Real), that is an important archaeological mine site in the region. In this place, different contamination levels can be finding in the soil and installations. The recovery of this site it will be of interest for the socio-economic development of the area. A preliminary study of the site has been carried out, in order to evaluate the possibility of the application of an in situ controlled mercury volatilization process as an alternative remediation technique. In case of reaching the established legal mercury levels, it could be possible to change the land use of the site. The proposed methodology includes the possibility of control the time required for a complete treatment as a function of the initial contamination level, in this way, the soil and installations decontamination process is performed by a non-destructive way. Finally, the proposed technology respects the old metallurgical plant where cinnabar was treated and burned, having the furnaces an elevated historical value whose restoration and conservation is important for the future use of the site. (Author) 20 refs.

  1. EDITORIAL: Mercury-free discharges for lighting

    Science.gov (United States)

    Haverlag, M.

    2007-07-01

    This special Cluster of articles in Journal of Physics D: Applied Physics covers the subject of mercury-free discharges that are being investigated by different light source researchers, as an alternative to existing mercury-containing lamps. The main driving force to move away from mercury-containing discharge light sources is connected to the environmentally unfriendly nature of mercury. After inhalation or direct contact, severe mercury exposure can lead to damage to human brain cells, the kidneys, the liver and the nervous system. For this reason, the use of mercury in products is becoming more and more restricted by different governmental bodies. In the lighting industry, however, many products still make use of mercury, for different reasons. The main reason is that mercury-containing products are, in most cases, more efficient than mercury-free products. For a realistic comparison of the environmental impact, the mercury-contamination due to electricity production must be taken into account, which depends on the type of fuel being used. For an average European fuel-mix, the amount of mercury that is released into the environment is around 29 μg kWh-1. This means that a typical 30 W TL lamp during a lifetime of 20,000 hours will release a total of about 20 mg mercury due to electricity production, which exceeds the total mercury dose in the lamp (more and more of which is being recycled) by a factor of 5-10 for a modern TL lamp. This illustrates that, quite apart from other environmental arguments like increased CO2 production, mercury-free alternatives that use more energy can in fact be detrimental for the total mercury pollution over the lifetime of the lamp. For this reason, the lighting industry has concentrated on lowering the mercury content in lamps as long as no efficient alternatives exist. Nevertheless, new initiatives for HID lamps and fluorescent lamps with more or less equal efficiency are underway, and a number of them are described in this

  2. Methods to reduce mercury pollution is small gold mining operations

    International Nuclear Information System (INIS)

    Pantoja-Timaran, F.; Alvarez-Rodriguez, R.; Rodriguez-Avello, A. S.

    2005-01-01

    The use of mercury for gold beneficiation is still a current practice in small mining operations, mainly in underdeveloped countries, due to the low investment required and necessity of easy to operate systems. But the lack of basic protections makes unavoidable the high pollution of water streams, soils, and in fact, human bodies. some improvements have been done at site like that related to the removal of the mercury from the amalgam, that usually was done in the open air, and now have been changed to the utilization of artisan iron retorts which considerable reduce the emissions of mercury vapors to the atmosphere, but there are still high losses of mercury into the waste solids or tailings coming from the amalgamation process (nearly most of the total weight of the ore treated). In order to reduce the mercury losses into the tailings from the process, this research work has been based in the use of cheap systems, available to the isolated miners, to proof that it is feasible to get an important reduction of the losses and the pollution. the procedure has been accomplished by means of washing the ores with alkaline or detergent agents, together with the use of activated mercury purified by electrowinning in a simple device, easily manufactured in site by the own workers. It is also proven herewith that controlling the time of amalgamation and the total amount of mercury used could reduce the total pollution, and in addition, the gold recovery would be improved. This investigation reports the possibility of a reduction of mercury losses down to 2.4 g per 100 of gold produced (case of rich ores like LaBruja), with gold recovery up to 94%; and 8,6 g per 100 g of gold produced (from ores with average grades like La Gruesa), and gold recoveries in the range of 92%. All that is about 20 to 100 times lower than data reported in current bibliography. The introduction of a previous step of the ore concentration in shaking tables, decreases the total amount of solids for

  3. Controlling dynamics in diatomic systems

    Indian Academy of Sciences (India)

    WINTEC

    2Center for Computational Natural Sciences and Bioinformatics,. International Institute of Information Technology, Hyderabad 500 032 ..... journal.34. 3. The control system. We have chosen two diatomic systems for studying the vibrational excitations from an initial state to a target state in a Morse potential of the HF and OH.

  4. Nova laser alignment control system

    International Nuclear Information System (INIS)

    Van Arsdall, P.J.; Holloway, F.W.; McGuigan, D.L.; Shelton, R.T.

    1984-01-01

    Alignment of the Nova laser requires control of hundreds of optical components in the ten beam paths. Extensive application of computer technology makes daily alignment practical. The control system is designed in a manner which provides both centralized and local manual operator controls integrated with automatic closed loop alignment. Menudriven operator consoles using high resolution color graphics displays overlaid with transport touch panels allow laser personnel to interact efficiently with the computer system. Automatic alignment is accomplished by using image analysis techniques to determine beam references points from video images acquired along the laser chain. A major goal of the design is to contribute substantially to rapid experimental turnaround and consistent alignment results. This paper describes the computer-based control structure and the software methods developed for aligning this large laser system

  5. Worldwide trend of atmospheric mercury since 1995

    Directory of Open Access Journals (Sweden)

    F. Slemr

    2011-05-01

    Full Text Available Concern about the adverse effects of mercury on human health and ecosystems has led to tightening emission controls since the mid 1980s. But the resulting mercury emissions reductions in many parts of the world are believed to be offset or even surpassed by the increasing emissions in rapidly industrializing countries. Consequently, concentrations of atmospheric mercury are expected to remain roughly constant. Here we show that the worldwide atmospheric mercury concentrations have decreased by about 20 to 38 % since 1996 as indicated by long-term monitoring at stations in the Southern and Northern Hemispheres combined with intermittent measurements of latitudinal distribution over the Atlantic Ocean. The total reduction of the atmospheric mercury burden of this magnitude within 14 years is unusually large among most atmospheric trace gases and is at odds with the current mercury emission inventories with nearly constant anthropogenic emissions over this period. This suggests a major shift in the biogeochemical cycle of mercury including oceans and soil reservoirs. Decreasing reemissions from the legacy of historical mercury emissions are the most likely explanation for this decline since the hypothesis of an accelerated oxidation rate of elemental mercury in the atmosphere is not supported by the observed trends of other trace gases. Acidification of oceans, climate change, excess nutrient input and pollution may also contribute by their impact on the biogeochemistry of ocean and soils. Consequently, models of the atmospheric mercury cycle have to include soil and ocean mercury pools and their dynamics to be able to make projections of future trends.

  6. Optimizing the mercury mass measurement in industrial electrolytic cells by the radio-tracer method at ININ

    International Nuclear Information System (INIS)

    Valle R, J.; Angeles C, A.

    2014-10-01

    One method used in the production of chlorine and sodium is the use of electrolytic cells for the separation of chlorine and sodium from the brine; the industries apply very intense electromagnetic fields in this process. The electrolytic cells use mercury as electrode. In a chlorine production plant inventories are determined by total amount of mercury in the plant annually, since mercury losses are large and a very important parameter is to control the mass of mercury for it is necessary to measure with great precision the losses made. There are several methods to determine the mass of mercury ranging from take samples and weigh, but this involves continuous interruption of the process creating downtimes which in turn represent economic losses giving a result delimiting productivity for the industrial sector. An alternative and attractive method is to use a radioactive tracer whose principle has a similar behavior to study objective. The inert mercury has to be neutron activated in a nuclear reactor to having the characteristics of a tracer; the result makes one of the isotopes of mercury. The tracer is transported taking into account the recommendations of the Comision Nacional de Seguridad Nuclear y Salvaguardias (Mexico), then it is injected into the electrolytic cells mixing with the mercury in the system. By a relative radioactivity measurement and one sample by gamma spectrometry per interest cell, the mass of mercury without stopping the process is obtained. For optimal use of radio-tracer method must be taken into account as important features: irradiation time of mercury, counting conditions, vial geometry, sample volume, sample cells, mixing time and half-life of the tracer. (Author)

  7. The AFP detector control system

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00514541; The ATLAS collaboration; Caforio, Davide; Czekierda, Sabina; Hajduk, Zbigniew; Olszowska, Jolanta; Sicho, Petr; Zabinski, Bartlomiej

    The ATLAS Forward Proton (AFP) detector is one of the forward detectors of the ATLAS experiment at CERN aiming at measuring momenta and angles of diffractively scattered protons. Silicon Tracking and Time-of-Flight detectors are located inside Roman Pot stations inserted into beam pipe aperture. The AFP detector is composed of two stations on each side of the ATLAS interaction point and is under commissioning. The detector is provided with high and low voltage distribution systems. Each station has vacuum and cooling systems, movement control and all the required electronics for signal processing. Monitoring of environmental parameters, like temperature and radiation, is also available. The Detector Control System (DCS) provides control and monitoring of the detector hardware and ensures the safe and reliable operation of the detector, assuring good data quality. Comparing with DCS systems of other detectors, the AFP DCS main challenge is to cope with the large variety of AFP equipment. This paper describes t...

  8. The AFP Detector Control System

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00514541; The ATLAS collaboration

    2017-01-01

    The ATLAS Forward Proton (AFP) detector is one of the forward detectors of the ATLAS experiment at CERN aiming at measuring momenta and angles of diffractively scattered protons. Silicon Tracking and Time-of-Flight detectors are located inside Roman Pot stations inserted into beam pipe aperture. The AFP detector is composed of two stations on each side of the ATLAS interaction point and is under commissioning. The detector is provided with high and low voltage distribution systems. Each station has vacuum and cooling systems, movement control and all the required electronics for signal processing. Monitoring of environmental parameters, like temperature and radiation, is also available. The Detector Control System (DCS) provides control and monitoring of the detector hardware and ensures the safe and reliable operation of the detector, assuring good data quality. Comparing with DCS systems of other detectors, the AFP DCS main challenge is to cope with the large variety of AFP equipment. This paper describes t...

  9. Safety implications of control systems

    International Nuclear Information System (INIS)

    Smith, O.L.

    1983-01-01

    The Safety Implications of Control Systems Program has three major activities in support of USI-A47. The first task is a failure mode and effects analysis of all plant systems which may potentially induce control system disturbance that have safety implications. This task has made a preliminary study of overfill events and recommended cases for further analysis on the hybrid simulator. Work continues on overcooling and undercooling. A detailed investigation of electric power network is in progress. LERs are providing guidance on important failure modes that will provide initial conditions for further simulator studies. The simulator taks is generating a detailed model of the control system supported by appropriate neutronics, hydraulics, and thermodynamics submodels of all other principal plant components. The simulator is in the last stages of development. Checkout calculations are in progress to establish model stability, robustness, and qualitative credibility. Verification against benchmark codes and plant data will follow

  10. Using species-specific enriched stable isotopes to study the effect of fresh mercury inputs in soil-earthworm systems.

    Science.gov (United States)

    Álvarez, C Rodríguez; Jiménez-Moreno, M; Bernardo, F J Guzmán; Martín-Doimeadios, R C Rodríguez; Nevado, J J Berzas

    2018-01-01

    The fate of mercury (Hg) in the soil-earthworm system is still far from being fully understood, especially regarding recurrent and challenging questions about the importance of the reactivity of exogenous Hg species. Thus, to predict the potential effect of Hg inputs in terrestrial ecosystems, it is necessary to evaluate separately the reactivity of the endogenous and exogenous Hg species and, for this purpose, the use of enriched stable isotope tracers is a promising tool. In the present work, earthworms (Lumbricus terrestris) were exposed to historically Hg contaminated soils from the Almadén mining district, Spain. The soils were either non-spiked, which contain only endogenous or native Hg naturally occurring in the soil, or spiked with isotopically enriched inorganic Hg ( 199 IHg), representing exogenous or spiked Hg apart from the native one. The differential reactivity of endogenous and exogenous Hg in the soil conditioned the processes of methylation, mobilization, and assimilation of inorganic Hg by earthworms. Both endogenous and exogenous Hg species also behave distinctly regarding their bioaccumulation in earthworms, as suggested by the bioaccumulation factors, being the endogenous methylmercury (MeHg) the species more readily bioaccumulated by earthworms and in a higher extent. To the best of our knowledge, this work demonstrates for the first time the potential of enriched stable isotopes to study the effects of fresh Hg inputs in soil-earthworm systems. The findings of this work can be taken as a case study on the dynamics of Hg species in complex terrestrial systems and open a new door for future experiments. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Mercury in products - a source of transboundary pollutant transport

    Energy Technology Data Exchange (ETDEWEB)

    Munthe, J.; Kindbom, K. [Swedish Environmental Research Inst., Stockholm (Sweden)

    1997-12-01

    The purpose of this report is to summarize current knowledge on product-related emissions of mercury to air on a European scale, and to estimate the contribution from mercury contained in products, to the total anthropogenic emissions of mercury to air and transboundary transport of mercury in Europe. Products included in this study are batteries, measuring and control instruments, light sources and electrical equipment, all intentionally containing mercury. The main result of this study is that product-related emission of mercury can contribute significantly to total emissions and transboundary transport of mercury in the European region and that measures to limit the use of mercury in products can contribute to an overall decrease of the environmental input of mercury in Europe. It is concluded that: -Mercury contained in products may be emitted to air during consumption, after disposal when incinerated or when volatilized from landfill. Mercury may also be emitted to air during recycling of scrap metal or when accumulated (stored) in society. -The amount of mercury consumed in batteries and in measuring and control instruments had decreased since the late 1980`s. The total use of mercury in light sources and electrical equipment has not changed significantly during the same time period. The contribution to total anthropogenic emissions of mercury to air in Europe in the mid 1990`s is estimated to be: for batteries 4%; for measuring and control instruments 3%; for lighting and electrical equipment 11%. -Mercury in products leads to significant wet deposition input in Scandinavia. The relative amount of the total deposition flux attributable to products is estimated to be 10-14% 26 refs, 4 figs, 10 tabs

  12. The new Aladdin control system

    International Nuclear Information System (INIS)

    Stott, J.P.; Eisert, D.E.

    1990-01-01

    The preliminary design of the new control system for the Aladdin electron-storage-ring light source was described at the Los Alamos workshop and an updated report was given at the Villars conference. The new system is now almost completely installed and this paper is a final report on the project. The major features of the system are the following: commercial hardware is used throughout the computer, network and microcomputer systems; the operator consoles and the device-control microcomputers are linked by Ethernet; VAXstations with keyboard and track-ball input devices are used in the operator consoles; the microcomputers use 68000-based single-board computers and VMEbus backplanes; the main magnet power supplies contain intelligent controllers which are linked to a microcomputer by a multidrop serial link; the microcomputer software is developed on the VAXstations; it is downloaded into RAM and debugged over the Ethernet before being burned into EPROMs for operational use. This paper describes the design of the system, highlighting changes from the previous proposals, and discusses the aspects which allowed the control system of an operating facility to be rebuilt without requiring or causing any significant downtime. The performance of the new system and possible future improvements are also discussed. (orig.)

  13. Urban artisanal gold shops and mercury emissions

    International Nuclear Information System (INIS)

    Cordy, P.; Veiga, M.; Carrasco, V.H.G.

    2008-01-01

    Artisanal miners in developing countries use mercury amalgamation processes to extract gold. The amalgams are then refined before being sold on to urban gold shops. The amalgams can often contain between 2 to 40 per cent mercury. Unburned amalgams are also often sold directly to gold shops. There are serious health risks for shop employees and nearby populations when the gold is melted and further purified. Studies have shown that mercury concentrations in the ambient air of gold shops often exceeds World Health Organization (WHO) limits by an order of magnitude or more. This study examined the practices and technologies used to refine gold in Latin America and Indonesia. The study compared and contrasted various refining methods and their resulting mercury emissions. Methods of reducing mercury emissions were also investigated, including a filtration system designed to capture 80 per cent of mercury emissions. Barriers to implementing mercury emissions reduction plans were also investigated. It was concluded that the design of urban gold shops must include condensers, fume hoods, and efficient mercury capture systems. 15 refs

  14. Urban artisanal gold shops and mercury emissions

    Energy Technology Data Exchange (ETDEWEB)

    Cordy, P.; Veiga, M.; Carrasco, V.H.G. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Mining and Mineral Process Engineering

    2008-07-01

    Artisanal miners in developing countries use mercury amalgamation processes to extract gold. The amalgams are then refined before being sold on to urban gold shops. The amalgams can often contain between 2 to 40 per cent mercury. Unburned amalgams are also often sold directly to gold shops. There are serious health risks for shop employees and nearby populations when the gold is melted and further purified. Studies have shown that mercury concentrations in the ambient air of gold shops often exceeds World Health Organization (WHO) limits by an order of magnitude or more. This study examined the practices and technologies used to refine gold in Latin America and Indonesia. The study compared and contrasted various refining methods and their resulting mercury emissions. Methods of reducing mercury emissions were also investigated, including a filtration system designed to capture 80 per cent of mercury emissions. Barriers to implementing mercury emissions reduction plans were also investigated. It was concluded that the design of urban gold shops must include condensers, fume hoods, and efficient mercury capture systems. 15 refs.

  15. Learning fuzzy logic control system

    Science.gov (United States)

    Lung, Leung Kam

    1994-01-01

    The performance of the Learning Fuzzy Logic Control System (LFLCS), developed in this thesis, has been evaluated. The Learning Fuzzy Logic Controller (LFLC) learns to control the motor by learning the set of teaching values that are generated by a classical PI controller. It is assumed that the classical PI controller is tuned to minimize the error of a position control system of the D.C. motor. The Learning Fuzzy Logic Controller developed in this thesis is a multi-input single-output network. Training of the Learning Fuzzy Logic Controller is implemented off-line. Upon completion of the training process (using Supervised Learning, and Unsupervised Learning), the LFLC replaces the classical PI controller. In this thesis, a closed loop position control system of a D.C. motor using the LFLC is implemented. The primary focus is on the learning capabilities of the Learning Fuzzy Logic Controller. The learning includes symbolic representation of the Input Linguistic Nodes set and Output Linguistic Notes set. In addition, we investigate the knowledge-based representation for the network. As part of the design process, we implement a digital computer simulation of the LFLCS. The computer simulation program is written in 'C' computer language, and it is implemented in DOS platform. The LFLCS, designed in this thesis, has been developed on a IBM compatible 486-DX2 66 computer. First, the performance of the Learning Fuzzy Logic Controller is evaluated by comparing the angular shaft position of the D.C. motor controlled by a conventional PI controller and that controlled by the LFLC. Second, the symbolic representation of the LFLC and the knowledge-based representation for the network are investigated by observing the parameters of the Fuzzy Logic membership functions and the links at each layer of the LFLC. While there are some limitations of application with this approach, the result of the simulation shows that the LFLC is able to control the angular shaft position of the

  16. Effe