Science.gov

Sample records for mercury target systems

  1. Mercury Handling for the Target System for a Muon Collider

    SciTech Connect

    Graves, Van B; Mcdonald, K; Kirk, H.; Weggel, Robert; Souchlas, Nicholas; Sayed, H; Ding, X

    2012-01-01

    The baseline target concept for a Muon Collider or Neutrino Factory is a free-stream mercury jet being impacted by an 8-GeV proton beam. The target is located within a 20-T magnetic field, which captures the generated pions that are conducted to a downstream decay channel. Both the mercury and the proton beam are introduced at slight downward angles to the magnetic axis. A pool of mercury serves as a receiving reservoir for the mercury and a dump for the unexpended proton beam. The impact energy of the remaining beam and jet are substantial, and it is required that splashes and waves be controlled in order to minimize the potential for interference of pion production at the target. Design issues discussed in this paper include the nozzle, splash mitigation in the mercury pool, the mercury containment vessel, and the mercury recirculation system.

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

    SciTech Connect

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

    2001-06-18

    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.

  3. Cavitation in a Mercury Target

    SciTech Connect

    West, C.D.

    2000-09-01

    Recent theoretical work on the formation of bubble nucleation centers by energetic particles leads to some reasonably credible calculations of the maximum negative pressure that might be sustained without bubble formation in the mercury target of the Spallation Neutron Source.

  4. "Cavitation in a Mercury Target"

    SciTech Connect

    West, C.D.

    2000-09-06

    Recent theoretical work on the formation of bubble nucleation centers by energetic particles leads to some reasonably credible calculations of the maximum negative pressure that might be sustained without bubble formation in the mercury target of the Spallation Neutron Source.

  5. Conceptual studies for a mercury target circuit

    SciTech Connect

    Sigg, B.

    1996-06-01

    For the now favored target design of the European Spallation Source project, i.e. the version using mercury as target material, a basic concept of the primary system has been worked out. It does not include a detailed design of the various components of the target circuit, but tries to outline a feasible solution for the system. Besides the removal of the thermal power of about 3MW produced in the target by the proton beam, the primary system has to satisfy a number of other requirements related to processing, safety, and operation. The basic proposal uses an electromagnetic pump and a mercury-water intermediate heat excanger, but other alternatives are also being discussed. Basic safety requirements, i.e. protection against radiation and toxic mercury vapours, are satisfied by a design using an air-tight primary system containment, double-walled tubes in the intermediate heat exchanger, a fail-safe system for decay heat removal, and a remote handling facility for the active part of the system. Much engineering work has still to be done, because many details of the design of the mercury and gas processing systems remain to be clarified, the thermal-hydraulic components need further optimisation, the system for control and instrumentation is only known in outline and a through safety analysis will be required.

  6. Optimized Parameters for a Mercury Jet Target

    SciTech Connect

    Ding, X.; Kirk, H.

    2010-12-01

    A study of target parameters for a high-power, liquid mercury jet target system for a neutrino factory or muon collider is presented. Using the MARS code, we simulate particle production initiated by incoming protons with kinetic energies between 2 and 100 GeV. For each proton beam energy, we maximize production by varying the geometric parameters of the target: the mercury jet radius, the incoming proton beam angle, and the crossing angle between the mercury jet and the proton beam. The number of muons surviving through an ionization cooling channel is determined as a function of the proton beam energy. We optimize the mercury jet target parameters: the mercury jet radius, the incoming proton beam angle and the crossing angle between the mercury jet and the proton beam for each proton beam energy. The optimized target radius varies from about 0.4 cm to 0.6 cm as the proton beam energy increases. The optimized beam angle varies from 75 mrad to 120 mrad. The optimized crossing angle is near 20 mrad for energies above 5 GeV. These values differ from earlier choices of 67 mrad for the beam angle and 33 mrad for the crossing angle. These new choices for the beam parameters increase the meson production by about 20% compared to the earlier parameters. Our study demonstrates that the maximum meson production efficiency per unit proton beam power occurs when the proton kinetic energy is in the range of 5-15 GeV. Finally, the dependence on energy of the number of muons at the end of the cooling channel is nearly identical to the dependence on energy of the meson production 50 m from the target. This demonstrates that the target parameters can be optimized without the additional step of running the distribution through a code such as ICOOL that simulates the bunching, phase rotation, and cooling.

  7. Mercury Calibration System

    SciTech Connect

    John Schabron; Eric Kalberer; Joseph Rovani; Mark Sanderson; Ryan Boysen; William Schuster

    2009-03-11

    U.S. Environmental Protection Agency (EPA) Performance Specification 12 in the Clean Air Mercury Rule (CAMR) states that a mercury CEM must be calibrated with National Institute for Standards and Technology (NIST)-traceable standards. In early 2009, a NIST traceable standard for elemental mercury CEM calibration still does not exist. Despite the vacature of CAMR by a Federal appeals court in early 2008, a NIST traceable standard is still needed for whatever regulation is implemented in the future. Thermo Fisher is a major vendor providing complete integrated mercury continuous emissions monitoring (CEM) systems to the industry. WRI is participating with EPA, EPRI, NIST, and Thermo Fisher towards the development of the criteria that will be used in the traceability protocols to be issued by EPA. An initial draft of an elemental mercury calibration traceability protocol was distributed for comment to the participating research groups and vendors on a limited basis in early May 2007. In August 2007, EPA issued an interim traceability protocol for elemental mercury calibrators. Various working drafts of the new interim traceability protocols were distributed in late 2008 and early 2009 to participants in the Mercury Standards Working Committee project. The protocols include sections on qualification and certification. The qualification section describes in general terms tests that must be conducted by the calibrator vendors to demonstrate that their calibration equipment meets the minimum requirements to be established by EPA for use in CAMR monitoring. Variables to be examined include linearity, ambient temperature, back pressure, ambient pressure, line voltage, and effects of shipping. None of the procedures were described in detail in the draft interim documents; however they describe what EPA would like to eventually develop. WRI is providing the data and results to EPA for use in developing revised experimental procedures and realistic acceptance criteria based on

  8. Two-phase flow model for energetic proton beam induced pressure waves in mercury target systems in the planned European Spallation Source

    NASA Astrophysics Data System (ADS)

    Barna, I. F.; Imre, A. R.; Rosta, L.; Mezei, F.

    2008-12-01

    Two-phase flow calculations are presented to investigate the thermo-hydraulical effects of the interaction between 2 ms long 1.3 GeV proton pulses with a closed mercury loop which can be considered as a model system of the target of the planned European Spallation Source (ESS) facility. The two-fluid model consists of six first-order partial differential equations that present one dimensional mass, momentum and energy balances for mercury vapor and liquid phases are capable to describe quick transients like cavitation effects or shock waves. The absorption of the proton beam is represented as instantaneous heat source in the energy balance equations. Densities and internal energies of the mercury liquid-vapor system is calculated from the van der Waals equation, but general method how to obtain such properties using arbitrary equation of state is also presented. A second order accurate high-resolution shock-capturing numerical scheme is applied with different kind of limiters in the numerical calculations. Our analysis show that even 75 degree temperature heat shocks cannot cause considerable cavitation effects in mercury.

  9. Optical diagnostics of mercury jet for an intense proton target.

    PubMed

    Park, H; Tsang, T; Kirk, H G; Ladeinde, F; Graves, V B; Spampinato, P T; Carroll, A J; Titus, P H; McDonald, K T

    2008-04-01

    An optical diagnostic system is designed and constructed for imaging a free mercury jet interacting with a high intensity proton beam in a pulsed high-field solenoid magnet. The optical imaging system employs a backilluminated, laser shadow photography technique. Object illumination and image capture are transmitted through radiation-hard multimode optical fibers and flexible coherent imaging fibers. A retroreflected illumination design allows the entire passive imaging system to fit inside the bore of the solenoid magnet. A sequence of synchronized short laser light pulses are used to freeze the transient events, and the images are recorded by several high speed charge coupled devices. Quantitative and qualitative data analysis using image processing based on probability approach is described. The characteristics of free mercury jet as a high power target for beam-jet interaction at various levels of the magnetic induction field is reported in this paper. PMID:18447556

  10. Cavitation damage prediction for the JSNS mercury target vessel

    NASA Astrophysics Data System (ADS)

    Naoe, Takashi; Kogawa, Hiroyuki; Wakui, Takashi; Haga, Katsuhiro; Teshigawara, Makoto; Kinoshita, Hidetaka; Takada, Hiroshi; Futakawa, Masatoshi

    2016-01-01

    The liquid mercury target system for the Japan Spallation Neutron Source (JSNS) at the Materials and Life science experimental Facility (MLF) in the Japan Proton Accelerator Research Complex (J-PARC) is designed to produce pulsed neutrons. The mercury target vessel in this system, which is made of type 316L stainless steel, is damaged by pressure wave-induced cavitation due to proton beam bombardment. Currently, cavitation damage is considered to be the dominant factor influencing the service life of the target vessel rather than radiation damage. In this study, cavitation damage to the interior surface of the target vessel was predicted on the basis of accumulated damage data from off-beam and on-beam experiments. The predicted damage was compared with the damage observed in a used target vessel. Furthermore, the effect of injecting gas microbubbles on cavitation damage was predicted through the measurement of the acoustic vibration of the target vessel. It was shown that the predicted depth of cavitation damage is reasonably coincident with the observed results. Moreover, it was confirmed that the injection of gas microbubbles had an effect on cavitation damage.

  11. Development of a gas layer to mitigate cavitation damage in liquid mercury spallation targets

    SciTech Connect

    Felde, David K; Wendel, Mark W; Riemer, Bernie

    2008-01-01

    Establish of a gas layer between the flowing liquid and container wall is proposed for mitigating the effects of cavitation in mercury spallation targets. Previous work has shown an order of magnitude decrease in damage for a gas layer developed in a stagnant mercury target for an in-beam experiment. This work is aimed at extending these results to the more complex conditions introduced by a flowing mercury target system. A water-loop has been fabricated to provide initial insights on potential gas injection methods into a flowing liquid. An existing full-scale flow loop designed to simulate the Spallation Neutron Source target system will be used to extend these studies to mercury. A parallel analytical effort is being conducted using computational fluid dynamics (CFD) modeling to provide direction to the experimental effort. Some preliminary simulations of gas injection through a single hole have been completed and show behavior of the models that is qualitatively meaningful.

  12. Spectral diagnostics of laser erosion plasma of mercury chalcogenide targets

    NASA Astrophysics Data System (ADS)

    Kotlyarchuk, B. K.; Popovych, D. I.; Savchuk, V. K.; Savitsky, V. G.

    1995-11-01

    The article sets out to investigate spatial-time and spectral characteristics of laser erosive vapor-plasma torch (EVT), formed at the vaporization of mercury chalcogenines targets. Its influence on the synthesis processes of HgTe and CdHgTe layers, condensed in mercury vapor, is described. It is shown that the laser radiation flux density and Hg vapor pressure in the reaction chamber are dominating factors which determine the character of gas-dynamic spread and EVT composition of mercury chalcogenides targets.

  13. Localized surface plasmon resonance mercury detection system and methods

    DOEpatents

    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.

  14. Mercury contamination study for flight system safety

    NASA Technical Reports Server (NTRS)

    Gorzynski, C. S., Jr.; Maycock, J. N.

    1972-01-01

    The effects and prevention of possible mercury pollution from the failure of solar electric propulsion spacecraft using mercury propellant were studied from tankage loading of post launch trajector injection. During preflight operations and initial flight mode there is little danger of mercury pollution if proper safety precautions are taken. Any spillage on the loading, mating, transportation, or launch pad areas is obvious and can be removed by vacuum cleaning soil and chemical fixing. Mercury spilled on Cape Kennedy ground soil will be chemically complexed and retained by the sandstone subsoil. A cover layer of sand or gravel on spilled mercury which has settled to the bottom of a water body adjacent to the system operation will control and eliminate the formation of toxic organic mercurials. Mercury released into the earth's atmosphere through leakage of a fireball will be diffused to low concentration levels. However, gas phase reactions of mercury with ozone could cause a local ozone depletion and result in serious ecological hazards.

  15. Design of an Intense Muon Source with a Carbon and Mercury Target

    SciTech Connect

    Stratakis, Diktys; Berg, J. Scott; Neuffer, David; Ding, Xiaoping

    2015-06-01

    In high-intensity sources, muons are produced by firing high energy protons onto a target to produce pions. The pions decay to muons which are captured and accelerated. In the present study, we examine the performance of the channel for two different target scenarios: one based on liquid mercury and another one based on a solid carbon target. We produce distributions with the two different target materials and discuss differences in particle spectrum near the sources. We then propagate the distributions through our capture system and compare the full system performance for the two target types.

  16. Design of an intense muon source with a carbon and mercury target

    SciTech Connect

    Stratakis, D.; Berg, J. S.; Neuffer, D.; Ding, X.

    2015-05-03

    In high-intensity sources, muons are produced by firing high energy protons onto a target to produce pions. The pions decay to muons which are captured and accelerated. In the present study, we examine the performance of the channel for two different target scenarios: one based on liquid mercury and another one based on a solid carbon target. We produce distributions with the two different target materials and discuss differences in particle spectrum near the sources. We then propagate the distributions through our capture system and compare the full system performance for the two target types.

  17. 21 CFR 862.3600 - Mercury test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 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...

  18. 21 CFR 862.3600 - Mercury test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 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...

  19. 21 CFR 862.3600 - Mercury test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 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...

  20. 21 CFR 862.3600 - Mercury test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 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...

  1. 21 CFR 862.3600 - Mercury test system.

    Code of Federal Regulations, 2010 CFR

    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...

  2. The MERIT (nTOF-11) High Intensity Liquid Mercury Target Experiment at the CERN PS

    SciTech Connect

    Efthymiopoulos, Ilias; Fabich, A.; Grudiev, A.; Haug, F.; Lettry, J.; Palm, M.; Pernegger, Heinz; Steerenberg, R.R.; Bennett, J.R.J.; Caretta, O.; Loveridge, P.; /Rutherford /Oak Ridge /Brookhaven /Princeton U. /Fermilab

    2008-06-01

    The MERIT(nTOF-11) experiment is a proof-of-principle test of a target system for a high power proton beam to be used as front-end for a neutrino factory or a muon collider. The experiment took data in autumn 2007 with the fast-extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of 30 x 10{sup 12} per pulse. The target system, based on a free mercury jet, is capable of intercepting a 4-MW proton beam inside a 15-T magnetic field required to capture the low energy secondary pions as the source for intense muon beams. Particle detectors installed around the target setup measure the secondary particle flux out of the target and can probe cavitation effects in the mercury jet when excited by an intense proton beam.Preliminary results of the data analysis will be presented here.

  3. The MERIT(nTOF-11) High Intensity Liquid Mercury Target Experiment at the CERN PS

    SciTech Connect

    Ethymiopoulos,I.; Fabich, A.; Palm, M.; Lettry, J.; Haug, F.; Pernegger, H.; Steerenberg, R.; Grudiev, A.; Kirk, H.G.; Tsang, T.; Mokhov, N.; Striganov, S.; Carroll, A.J.; Graves, V.B.; Spampinato, P.T.; McDonald, K.T.; Bennett, J.R.J.; Caretta, O.; Loveridge, P.; Park, H.

    2008-06-23

    The MERIT(nTOF-11) experiment is a proof-of-principle test of a target system for a high power proton beam to be used as front-end for a neutrino factory or a muon collider. The experiment took data in autumn 2007 with the fast-extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of 30 x 10{sup 12} per pulse. The target system, based on a free mercury jet, is capable of intercepting a 4-MW proton beam inside a 15-T magnetic field required to capture the low energy secondary pions as the source for intense muon beams. Particle detectors installed around the target setup measure the secondary particle flux out of the target and can probe cavitation effects in the mercury jet when excited by an intense proton beam.Preliminary results of the data analysis will be presented here.

  4. The MERIT(nTOF-11) High Intensity Liquid Mercury Target Experiment at the CERN PS

    SciTech Connect

    Efthymiopoulos, I.; Fabich, A.; Palm, M.; Lettry, J.; Haug, F.; Pernegger, H.; Steerenberg, R.; Grudiev, A.; Kirk, H.g.; Tsang, t.; Mokbov, N.; /Fermilab /Oak Ridge /Princeton U. /Rutherford /SUNY, Stony Brook

    2008-06-01

    The MERIT(nTOF-11) experiment is a proof-of-principle test of a target system for a high power proton beam to be used as front-end for a neutrino factory or a muon collider. The experiment took data in autumn 2007 with the fast-extracted beam from the CERN Proton Synchrotron (PS) to a maximum intensity of 30 x 10{sup 12} per pulse. The target system, based on a free mercury jet, is capable of intercepting a 4-MW proton beam inside a 15-T magnetic field required to capture the low energy secondary pions as the source for intense muon beams. Particle detectors installed around the target setup measure the secondary particle flux out of the target and can probe cavitation effects in the mercury jet when excited by an intense proton beam. Preliminary results of the data analysis will be presented here.

  5. Mercury sorbent delivery system for flue gas

    DOEpatents

    Klunder; ,Edgar B.

    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.

  6. Mercury

    NASA Astrophysics Data System (ADS)

    Taylor, G. J.; Scott, E. R. D.

    2003-12-01

    Mercury is an important part of the solar system puzzle, yet we know less about it than any other planet, except Pluto. Mercury is the smallest of the terrestrial planets (0.05 Earth masses) and the closest to the Sun. Its relatively high density (5.4 g cm -3) indicates that it has a large metallic core (˜3/4 of the planet's radius) compared to its silicate mantle and crust. The existence of a magnetic field implies that the metallic core is still partly molten. The surface is heavily cratered like the highlands of the Moon, but some areas are smooth and less cratered, possibly like the lunar maria (but not as dark). Its surface composition, as explained in the next section, appears to be low in FeO (only ˜3 wt.%), which implies that either its crust is anorthositic (Jeanloz et al., 1995) or its mantle is similarly low in FeO ( Robinson and Taylor, 2001).The proximity of Mercury to the Sun is particularly important. In one somewhat outmoded view of how the solar system formed, Mercury was assembled in the hottest region close to the Sun so that virtually all of the iron was in the metallic state, rather than oxidized to FeO (e.g., Lewis, 1972, 1974). If correct, Mercury ought to have relatively a low content of FeO. This hypothesis also predicts that Mercury should have high concentrations of refractory elements, such as calcium, aluminum, and thorium, and low concentrations of volatile elements, such as sodium and potassium, compared to the other terrestrial planets.Alternative hypotheses tell a much more nomadic and dramatic story of Mercury's birth. In one alternative view, wandering planetesimals that might have come from as far away as Mars or the inner asteroid belt accreted to form Mercury (Wetherill, 1994). This model predicts higher FeO and volatile elements than does the high-temperature model, and similar compositions among the terrestrial planets. The accretion process might have been accompanied by a monumental impact that stripped away much of the

  7. Mercury-metadata data management system

    Energy Science and Technology Software Center (ESTSC)

    2008-01-03

    Mercury is a federated metadata harvesting, search and retrieval tool based on both open source software and software developed at Oak Ridge National Laboratory. It was originally developed for NASA, USGS, and DOE. A major new version of Mercury (version 3.0) was developed during 2007 and released in early 2008. This Mercury 3.0 version provides orders of magnitude improvements in search speed, support for additional metadata formats, integration with Google Maps for spatial queries, facettedmore » type search, support for RSS delivery of search results, and ready customization to meet the needs of the multiple projects which use Mercury. For the end users, Mercury provides a single portal to very quickly search for data and 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.« less

  8. Mercury-metadata data management system

    SciTech Connect

    2008-01-03

    Mercury is a federated metadata harvesting, search and retrieval tool based on both open source software and software developed at Oak Ridge National Laboratory. It was originally developed for NASA, USGS, and DOE. A major new version of Mercury (version 3.0) was developed during 2007 and released in early 2008. This Mercury 3.0 version 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 delivery of search results, and ready customization to meet the needs of the multiple projects which use Mercury. For the end users, Mercury provides a single portal to very quickly search for data and 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.

  9. DEVELOPMENT OF A WATERSHED-BASED MERCURY POLLUTION CHARACTERIZATION SYSTEM

    EPA Science Inventory

    To investigate total mercury loadings to streams in a watershed, we have developed a watershed-based source quantification model ? Watershed Mercury Characterization System. The system uses the grid-based GIS modeling technology to calculate total soil mercury concentrations and ...

  10. Mercury

    MedlinePlus

    ... button batteries. Mercury salts may be used in skin creams and ointments. It's also used in many industries. Mercury in the air settles into water. It can pass through the food chain and build up in ...

  11. Mercury

    MedlinePlus

    Mercury is an element that is found in air, water and soil. It has several forms. Metallic mercury is a shiny, silver-white, ... colorless, odorless gas. It also combines with other elements to form powders or crystals. Mercury is in ...

  12. Three-dimensional computational fluid dynamics for the Spallation Neutron Source liquid mercury target

    SciTech Connect

    Wendel, M.W.; Siman-Tov, M.

    1998-11-01

    The Spallation Neutron Source (SNS) is a high-power accelerator-based pulsed spallation source being designed by a multilaboratory team led by Oak Ridge National Laboratory (ORNL) to achieve high fluxes of neutrons for scientific experiments. Computational fluid dynamics (CFD) is being used to analyze the SNS design. The liquid-mercury target is subjected to the neutronic (internal) heat generation that results from the proton collisions with the mercury nuclei. The liquid mercury simultaneously serves as the neutronic target medium, transports away the heat generated within itself, and cools the metallic target structure. Recirculation and stagnation zones within the target are of particular concern because of the likelihood that they will result in local hot spots. These zones exist because the most feasible target designs include a complete U-turn flow redirection. Although the primary concern is that the target is adequately cooled, the pressure drop from inlet to outlet must also be considered because pressure drop directly affects structural loading and required pumping power. Based on the current design, a three-dimensional CFD model has been developed that includes the stainless steel target structure, the liquid-mercury target flow, and the liquid-mercury cooling jacket that wraps around the nose of the target.

  13. Mercury target R&D for the Oak Ridge spallation neutron source

    SciTech Connect

    Haines, J.R.; DiStefano, J.; Farrell, K.; Gabriel, T.A.

    1996-06-01

    The conceptual design for the Oak Ridge Spallation Neutron Source (ORSNS) incorporates liquid mercury as its reference target material. A flowing liquid target was selected mainly because of the increased power handling capability possible with the convective transport process. The major reasons for choosing mercury as the liquid target material are because it: (1) is a liquid at room temperature, (2) has good heat transport properties, and (3) has a high atomic number and mass density resulting in high neutron yield and source brightness. Since liquid targets are not widely utilized in presently operating accelerator targets and because of the challenges posed by the intense, pulsed thermal energy deposition ({approximately}20-100 kJ deposited during each 1-10 {mu}s pulse), considerable R&D is planned for the mercury target concept. The key feasibility issue that will be addressed in early R&D efforts are the effects of the thermal shock environment, which will include development and testing of approaches to mitigate these effects. Materials compatiblity and ES&H issues associated with the use of liquid mercury are also of major importance in early R&D efforts. A brief description of the mercury target design concept, results of initial evaluations of its performance characteristics, identification of its critical issues, and an outline of the R&D program aimed at addressing these issues will be presented.

  14. Cavitation Damage Experiments for Mercury Spallation Targets At the LANSCE WNR in 2008

    SciTech Connect

    Riemer, Bernie; Wendel, Mark W; Felde, David K

    2010-01-01

    Proton beam experiments investigating cavitation damage in short pulse mercury spallation targets were performed at LANSCE WNR in July of 2008. They included two main areas for investigation: damage dependence on mercury velocity using geometry more prototypic to the SNS target than previously employed and damage dependence on incident proton beam flux intensity. The flow dependence experiment employed six test targets with mercury velocity in the channel ranging from 0 to more than 4 m/s. Each was hit with 100 WNR beam pulses with peak proton flux equivalent to that of SNS operating at 2.7 MW. Damage dependence on incident proton beam flux intensity was also investigated with three intensity levels used on simple rectangular shaped targets without mercury flow. Intensity variation was imposed by focusing the beam differently while maintaining protons per pulse. This kept total energy deposited in each target constant. A fourth test target was hit with various beams: constant protons and varied spot size; constant spot size and varied protons. No damage will be assessed in this case. Instead, acoustic emissions associated with cavitation collapse were measured by laser Doppler vibrometer (LDV) from readings of exterior vessel motions as well as by mercury wetted acoustic transducers. This paper will provide a description of the experiment and present available results. Damage assessment will require several months before surface analysis can be completed and was not available in time for IWSMT-9.

  15. Optical system design and integration of the mercury laser altimeter.

    PubMed

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

    2005-03-20

    The Mercury Laser Altimeter (MLA), developed for the 2004 MESSENGER mission to Mercury, is designed to measure the planet's topography by 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. PMID:15813279

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

    NASA Technical Reports Server (NTRS)

    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.

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

    SciTech Connect

    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.

  18. Mercury

    MedlinePlus

    ... be found in: Batteries Chemistry labs Some disinfectants Folk remedies Red cinnabar mineral Organic mercury can be ... heart tracing Fluids through a vein (by IV) Medicine to treat symptoms The type of exposure will ...

  19. Subcellular Targeting of Methylmercury Lyase Enhances Its Specific Activity for Organic Mercury Detoxification in Plants1

    PubMed Central

    Bizily, Scott P.; Kim, Tehryung; Kandasamy, Muthugapatti K.; Meagher, Richard B.

    2003-01-01

    Methylmercury is an environmental pollutant that biomagnifies in the aquatic food chain with severe consequences for humans and other animals. In an effort to remove this toxin in situ, we have been engineering plants that express the bacterial mercury resistance enzymes organomercurial lyase MerB and mercuric ion reductase MerA. In vivo kinetics experiments suggest that the diffusion of hydrophobic organic mercury to MerB limits the rate of the coupled reaction with MerA (Bizily et al., 2000). To optimize reaction kinetics for organic mercury compounds, the merB gene was engineered to target MerB for accumulation in the endoplasmic reticulum and for secretion to the cell wall. Plants expressing the targeted MerB proteins and cytoplasmic MerA are highly resistant to organic mercury and degrade organic mercury at 10 to 70 times higher specific activity than plants with the cytoplasmically distributed wild-type MerB enzyme. MerB protein in endoplasmic reticulum-targeted plants appears to accumulate in large vesicular structures that can be visualized in immunolabeled plant cells. These results suggest that the toxic effects of organic mercury are focused in microenvironments of the secretory pathway, that these hydrophobic compartments provide more favorable reaction conditions for MerB activity, and that moderate increases in targeted MerB expression will lead to significant gains in detoxification. In summary, to maximize phytoremediation efficiency of hydrophobic pollutants in plants, it may be beneficial to target enzymes to specific subcellular environments. PMID:12586871

  20. Formation of nanocolloidal metacinnabar in mercury-DOM-sulfide systems

    USGS Publications Warehouse

    Gerbig, C.A.; Kim, C.S.; Stegemeier, J.P.; Ryan, J.N.; Aiken, G.R.

    2011-01-01

    Direct determination of mercury (Hg) speciation in sulfide-containing environments is confounded by low mercury concentrations and poor analytical sensitivity. Here we report the results of experiments designed to assess mercury speciation at environmentally relevant ratios of mercury to dissolved organic matter (DOM) (i.e., <4 nmol Hg (mg DOM)-1) by combining solid phase extraction using C18 resin with extended X-ray absorption fine structure (EXAFS) spectroscopy. Aqueous Hg(II) and a DOM isolate were equilibrated in the presence and absence of 100 ??M total sulfide. In the absence of sulfide, mercury adsorption to the resin increased as the Hg:DOM ratio decreased and as the strength of Hg-DOM binding increased. EXAFS analysis indicated that in the absence of sulfide, mercury bonds with an average of 2.4 ?? 0.2 sulfur atoms with a bond length typical of mercury-organic thiol ligands (2.35 ??). In the presence of sulfide, mercury showed greater affinity for the C18 resin, and its chromatographic behavior was independent of Hg:DOM ratio. EXAFS analysis showed mercury-sulfur bonds with a longer interatomic distance (2.51-2.53 ??) similar to the mercury-sulfur bond distance in metacinnabar (2.53 ??) regardless of the Hg:DOM ratio. For all samples containing sulfide, the sulfur coordination number was below the ideal four-coordinate structure of metacinnabar. At a low Hg:DOM ratio where strong binding DOM sites may control mercury speciation (1.9 nmol mg -1) mercury was coordinated by 2.3 ?? 0.2 sulfur atoms, and the coordination number rose with increasing Hg:DOM ratio. The less-than-ideal coordination numbers indicate metacinnabar-like species on the nanometer scale, and the positive correlation between Hg:DOM ratio and sulfur coordination number suggests progressively increasing particle size or crystalline order with increasing abundance of mercury with respect to DOM. In DOM-containing sulfidic systems nanocolloidal metacinnabar-like species may form, and these

  1. Evaluation of Background Mercury Concentrations in the SRS Groundwater System

    SciTech Connect

    Looney, B.B.

    1999-03-03

    Mercury analyses associated with the A-01 Outfall have highlighted the importance of developing an understanding of mercury in the Savannah River Site groundwater system and associated surface water streams. This activity is critical based upon the fact that the EPA Ambient Water Quality Criteria (AWQC) for this constituent is 0.012mg/L, a level that is well below conventional detection limits of 0.1 to 0.2 mg/L. A first step in this process is obtained by utilizing the existing investment in groundwater mercury concentrations (20,242 records) maintained in the SRS geographical information management system (GIMS) database. Careful use of these data provides a technically defensible initial estimate for total recoverable mercury in background and contaminated SRS wells.

  2. Formation of nanocolloidal metacinnabar in mercury-DOM-sulfide systems

    USGS Publications Warehouse

    Gerbig, Chase A.; Kim, Christopher S.; Stegemeier, John P.; Ryan, Joseph N.; Aiken, George R.

    2011-01-01

    Direct determination of mercury (Hg) speciation in sulfide-containing environments is confounded by low mercury concentrations and poor analytical sensitivity. Here we report the results of experiments designed to assess mercury speciation at environmentally relevant ratios of mercury to dissolved organic matter (DOM) (i.e., -1) by combining solid phase extraction using C18 resin with extended X-ray absorption fine structure (EXAFS) spectroscopy. Aqueous Hg(II) and a DOM isolate were equilibrated in the presence and absence of 100 μM total sulfide. In the absence of sulfide, mercury adsorption to the resin increased as the Hg:DOM ratio decreased and as the strength of Hg-DOM binding increased. EXAFS analysis indicated that in the absence of sulfide, mercury bonds with an average of 2.4 ± 0.2 sulfur atoms with a bond length typical of mercury-organic thiol ligands (2.35 Å). In the presence of sulfide, mercury showed greater affinity for the C18 resin, and its chromatographic behavior was independent of Hg:DOM ratio. EXAFS analysis showed mercury–sulfur bonds with a longer interatomic distance (2.51–2.53 Å) similar to the mercury–sulfur bond distance in metacinnabar (2.53 Å) regardless of the Hg:DOM ratio. For all samples containing sulfide, the sulfur coordination number was below the ideal four-coordinate structure of metacinnabar. At a low Hg:DOM ratio where strong binding DOM sites may control mercury speciation (1.9 nmol mg-1) mercury was coordinated by 2.3 ± 0.2 sulfur atoms, and the coordination number rose with increasing Hg:DOM ratio. The less-than-ideal coordination numbers indicate metacinnabar-like species on the nanometer scale, and the positive correlation between Hg:DOM ratio and sulfur coordination number suggests progressively increasing particle size or crystalline order with increasing abundance of mercury with respect to DOM. In DOM-containing sulfidic systems nanocolloidal metacinnabar-like species may form, and these species need to

  3. AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF FOUR MERCURY EMISSION SAMPLING SYSTEMS

    EPA Science Inventory

    CEMs - Tekran Instrument Corp. Series 3300 and Thermo Electron's Mercury Freedom System Continuous Emission Monitors (CEMs) for mercury are designed to determine total and/or chemically speciated vapor-phase mercury in combustion emissions. Performance for mercury CEMs are cont...

  4. Advanced Materials for Mercury 50 Gas Turbine Combustion System

    SciTech Connect

    Price, Jeffrey

    2008-09-30

    Solar Turbines Incorporated (Solar), under cooperative agreement number DE-FC26-0CH11049, has conducted development activities to improve the durability of the Mercury 50 combustion system to 30,000 hours life and reduced life cycle costs. This project is part of Advanced Materials in the Advanced Industrial Gas Turbines program in DOE's Office of Distributed Energy. The targeted development engine was the Mercury{trademark} 50 gas turbine, which was developed by Solar under the DOE Advanced Turbine Systems program (DOE contract number DE-FC21-95MC31173). As a generator set, the Mercury 50 is used for distributed power and combined heat and power generation and is designed to achieve 38.5% electrical efficiency, reduced cost of electricity, and single digit emissions. The original program goal was 20,000 hours life, however, this goal was increased to be consistent with Solar's standard 30,000 hour time before overhaul for production engines. Through changes to the combustor design to incorporate effusion cooling in the Generation 3 Mercury 50 engine, which resulted in a drop in the combustor wall temperature, the current standard thermal barrier coated liner was predicted to have 18,000 hours life. With the addition of the advanced materials technology being evaluated under this program, the combustor life is predicted to be over 30,000 hours. The ultimate goal of the program was to demonstrate a fully integrated Mercury 50 combustion system, modified with advanced materials technologies, at a host site for a minimum of 4,000 hours. Solar was the Prime Contractor on the program team, which includes participation of other gas turbine manufacturers, various advanced material and coating suppliers, nationally recognized test laboratories, and multiple industrial end-user field demonstration sites. The program focused on a dual path development route to define an optimum mix of technologies for the Mercury 50 and future gas turbine products. For liner and injector

  5. Short-pulse Laser Capability on the Mercury Laser System

    SciTech Connect

    Ebbers, C; Armstrong, P; Bayramian, A; Barty, C J; Bibeau, C; Britten, J; Caird, J; Campbell, R; Chai, B; Crane, J; Cross, R; Erlandson, A; Fei, Y; Freitas, B; Jovanovic, I; Liao, Z; Molander, B; Schaffers, K; Stuart, B; Sutton, S; Ladran, T; Telford, S; Thelin, P; Utterback, E

    2006-06-22

    Applications using high energy ''petawatt-class'' laser drivers operating at repetition rates beyond 0.01 Hz are only now being envisioned. The Mercury laser system is designed to operate at 100 J/pulse at 10 Hz. We investigate the potential of configuring the Mercury laser to produce a rep-rated, ''petawatt-class'' source. The Mercury laser is a prototype of a high energy, high repetition rate source (100 J, 10 Hz). The design of the Mercury laser is based on the ability to scale in energy through scaling in aperture. Mercury is one of several 100 J, high repetition rate (10 Hz) lasers sources currently under development (HALNA, LUCIA, POLARIS). We examine the possibility of using Mercury as a pump source for a high irradiance ''petawatt-class'' source: either as a pump laser for an average power Ti:Sapphire laser, or as a pump laser for OPCPA based on YCa{sub 4}O(BO{sub 3}){sub 3} (YCOB), ideally producing a source approaching 30 J /30 fs /10 Hz--a high repetition rate petawatt. A comparison of the two systems with nominal configurations and efficiencies is shown in Table 1.

  6. Mercury

    NASA Technical Reports Server (NTRS)

    Gault, D. E.; Burns, J. A.; Cassen, P.; Strom, R. G.

    1977-01-01

    Prior to the flight of the Mariner 10 spacecraft, Mercury was the least investigated and most poorly known terrestrial planet (Kuiper 1970, Devine 1972). Observational difficulties caused by its proximity to the Sun as viewed from Earth caused the planet to remain a small, vague disk exhibiting little surface contrast or details, an object for which only three major facts were known: 1. its bulk density is similar to that of Venus and Earth, much greater than that of Mars and the Moon; 2. its surface reflects electromagnetic radiation at all wavelengths in the same manner as the Moon (taking into account differences in their solar distances); and 3. its rotation period is in 2/3 resonance with its orbital period. Images obtained during the flyby by Mariner 10 on 29 March 1974 (and the two subsequent flybys on 21 September 1974 and 16 March 1975) revealed Mercury's surface in detail equivalent to that available for the Moon during the early 1960's from Earth-based telescopic views. Additionally, however, information was obtained on the planet's mass and size, atmospheric composition and density, charged-particle environment, and infrared thermal radiation from the surface, and most significantly of all, the existence of a planetary magnetic field that is probably intrinsic to Mercury was established. In the following, this new information is summarized together with results from theoretical studies and ground-based observations. In the quantum jumps of knowledge that have been characteristic of "space-age" exploration, the previously obscure body of Mercury has suddenly come into sharp focus. It is very likely a differentiated body, probably contains a large Earth-like iron-rich core, and displays a surface remarkably similar to that of the Moon, which suggests a similar evolutionary history.

  7. Mercury emissions control by wet FGD systems: EPRI pilot-scale results

    SciTech Connect

    Peterson, J.R.; Hargrove, O.W. Jr.; Seeger, D.M.

    1995-06-01

    This paper presents results from pilot-scale tests that investigated mercury removal across wet limestone flue gas desulfurization (FGD) systems. The program was conducted at EPRIs Environmental Control Technology Center, located in Barker, NY. The test results showed that mercuric chloride (HgCl{sub 2}) was efficiently removed across the FGD system, while elemental mercury was not collected. The practical implication of this study is that although FGD systems efficiently remove some forms of mercury from flue gas, the overall mercury removal efficiency, and therefore the total mercury emissions from a coal-fired power plant equipped with an FGD system, will depend on the chemical form of the mercury in the flue gas. Unfortunately, no validated gas sampling method is available for speciating the different forms of mercury in flue gas. It is, therefore, difficult to predict mercury removal across FGD systems and to interpret any mercury removal data that have been collected.

  8. Global Mercury Observatory System (GMOS): measurements of atmospheric mercury in Celestun, Yucatan, Mexico during 2012.

    PubMed

    Velasco, Antonio; Arcega-Cabrera, Flor; Oceguera-Vargas, Ismael; Ramírez, Martha; Ortinez, Abraham; Umlauf, Gunther; Sena, Fabrizio

    2016-09-01

    Within the Global Mercury Observation System (GMOS) project, long-term continuous measurements of total gaseous mercury (TGM) were carried out by a monitoring station located at Celestun, Yucatan, Mexico, a coastal site along the Gulf of Mexico. The measurements covered the period from January 28th to October 17th, 2012. TGM data, at the Celestun site, were obtained using a high-resolution mercury vapor analyzer. TGM data show values from 0.50 to 2.82 ng/m(3) with an annual average concentration of 1.047 ± 0.271 ng/m(3). Multivariate analyses of TGM and meteorological variables suggest that TGM is correlated with the vertical air mass distribution in the atmosphere, which is influenced by diurnal variations in temperature and relative humidity. Diurnal variation is characterized by higher nighttime mercury concentrations, which might be influenced by convection currents between sea and land. The back trajectory analysis confirmed that local sources do not significantly influence TGM variations. This study shows that TGM monitoring at the Celestun site fulfills GMOS goals for a background site. PMID:27230151

  9. THERMODYNAMIC INTERACTION OF THE PRIMARY PROTON BEAM WITH A MERCURY JET TARGET AT A NEUTRINO FACTORY SOURCE.

    SciTech Connect

    SIMOS,N.; LUDEWIG,H.; KIRK,H.; THIEBERGER,P.; MCDONALD,K.

    2001-06-18

    This paper addresses the thermodynamic interaction of an intense proton beam with the proposed mercury jet target at a neutrino factory or muon collider source, and the consequences of the generated pressure waves on the target integrity. Specifically, a 24 GeV proton beam with approximately 1.6e13 protons per pulse and a pulse length of 2 nanosec will interact with a 1 cm diameter mercury jet within a 20 Tesla magnetic field. In one option, a train of six such proton pulses is to be delivered on target within 2 microsec, in which case the state of the mercury jet following the interaction with each pulse is critical. Using the equation of state for mercury from the SESAME library, in combination with the energy deposition rates calculated the by the hadron interaction code MARS, the induced 3-D pressure field in the target is estimated. The consequent pressure wave propagation and attenuation in the mercury jet is calculated using an ANSYS code transient analysis, and the state of the mercury jet at the time of arrival of the subsequent pulse is assessed. The amplitude of the pressure wave reaching the nozzle that ejects the mercury jet into the magnetic field is estimated and the potential for mechanical damage is addressed.

  10. Thermal-hydraulic simulation of mercury target concepts for a pulsed spallation neutron source

    SciTech Connect

    Siman-Tov, M.; Wendel, M.; Haines, J.

    1996-06-01

    The Oak Ridge Spallation Neutron Source (ORSNS) is a high-power, accelerator-based pulsed spallation neutron source being designed by a multi-laboratory team led by Oak Ridge National Laboratory to achieve very high fluxes of neutrons for scientific experiments. The ORSNS is projected to have a 1 MW proton beam upgradable to 5 MW. About 60% of the beam power (1-5 MW, 17-83 kJ/pulse in 0.5 microsec at 60 cps) is deposited in the liquid metal (mercury) target having the dimensions of 65x30x10 cm (about 19.5 liter). Peak steady state power density is about 150 and 785 MW/m{sup 3} for 1 MW and 5 MW beam respectively, whereas peak pulsed power density is as high as 5.2 and 26.1 GW/m{sup 3}, respectively. The peak pulse temperature rise rate is 14 million C/s (for 5 MW beam) whereas the total pulse temperature rise is only 7 C. In addition to thermal shock and materials compatibility, key feasibility issues for the target are related to its thermal-hydraulic performance. This includes proper flow distribution, flow reversals, possible {open_quotes}hot spots{close_quotes} and the challenge of mitigating the effects of thermal shock through possible injection of helium bubbles throughout the mercury volume or other concepts. The general computational fluid dynamics (CFD) code CFDS-FLOW3D was used to simulate the thermal and flow distribution in three preliminary concepts of the mercury target. Very initial CFD simulation of He bubbles injection demonstrates some potential for simulating behavior of He bubbles in flowing mercury. Much study and development will be required to be able to `predict`, even in a crude way, such a complex phenomena. Future direction in both design and R&D is outlined.

  11. RESULTS FROM CAVITATION DAMAGE EXPERIMENTS WITH MERCURY SPALLATION TARGETS AT THE LANSCE WNR IN 2008

    SciTech Connect

    Riemer, Bernie; Abdou, Ashraf A; Felde, David K; Sangrey, Robert L; Wendel, Mark W

    2010-01-01

    Damage assessment from proton beam induced cavitation experiments on mercury spallation targets done at the LANSCE WNR facility has been completed. The experiments investigated two key questions for the Spallation Neutron Source target, namely, how damage is affected by flow velocity in the SNS coolant channel geometry, and how damage scales with proton beam intensity at a given constant charge per pulse. With regard to the former question, prior in-beam experiments indicated that the coolant channel geometry with stagnant mercury was especially vulnerable to damage which might warrant a design change. Yet other results indicated a reduction in damage with the introduction of flow. Using more prototypic to the SNS, the 2008 experiment damage results show the channel is less vulnerable than the bulk mercury side of the vessel wall. They also show no benefit from increasing channel flow velocity beyond nominal SNS speeds. The second question probed a consensus belief that damage scales with beam intensity (protons per unit area) by a power law dependence with exponent of around 4. Results from a 2005 experiment did not support this power law dependence but some observations were inconsistent and unexplained. These latest results show weaker damage dependence.

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

    DOEpatents

    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.

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

    USGS Publications Warehouse

    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.

  14. INTERACTION OF A 24 GEV PROTON BEAM IWHT A MUON COLLIDER MERCURY JET TARGET EXPERIMENTAL RESULTS AND THERMODYNAMIC ASSESSMENT.

    SciTech Connect

    SIMOS,N.; KIRK,H.; FINFROCK,C.; GREENE,G.; LUDEWIG,H.; MCDONALD,K.; MOKHOV,N.

    2001-11-11

    A muon collider or a neutrino factory based on a muon storage ring require intense beams of muons that can be generated by a 1-4 MW proton beam incident on a moving target inside a 20-T solenoid magnet, with a mercury jet as a preferred example. This paper addresses the thermodynamic interaction of the intense proton beam with the proposed mercury jet target, and the consequences of the generated pressure waves on the target integrity. Specifically, a 24 GeV proton beam with approximately 16 TP (1 TP = 10{sup 12} protons) per pulse and a pulse length of 2 ns will interact with a 1 cm diameter mercury jet within the 20-Tesla magnetic field. In one option, a train of six such proton pulses is to be delivered on target within 2 {micro}s, in which case the state of the mercury jet following the interaction with each pulse is critical. Using the equation of state for mercury from the SESAME library, in combination with the energy deposition rates calculated the by the hadron interaction code MARS, the induced 3-D pressure field in the target is estimated. The consequent pressure wave propagation and attenuation in the mercury jet is calculated using a transient analysis based on finite element modeling, and the state of the mercury jet at the time of arrival of the subsequent pulse is assessed. Issues associated with the use of a liquid metal jet as a target candidate are addressed. Lastly, some experimental results from the BNL E951 experiment are presented and discussed.

  15. MERCURY OXIDIZATION IN NON-THERMAL PLASMA BARRIER DISCHARGE SYSTEM

    SciTech Connect

    V.K. Mathur

    2003-02-01

    In the past decade, the emission of toxic elements from human activities has become a matter of great public concern. Hg, As, Se and Cd typically volatilize during a combustion process and are not easily caught with conventional air pollution control techniques. In addition, there is no pollution prevention technique available now or likely be available in the foreseeable future that can prevent the emission of these trace elements. These trace elements pose additional scientific challenge as they are present at only ppb levels in large gas streams. Mercury, in particular, has attracted significant attention due to its high volatility, toxicity and potential threat to human health. In the present research work, a non-thermal plasma dielectric barrier discharge technique has been used to oxidize Hg{sup 0}(g) to HgO. The basic premise of this approach is that Hg{sup 0} in vapor form cannot be easily removed in an absorption tower whereas HgO as a particulate is amiable to water scrubbing. The work presented in this report consists of three steps: (1) setting-up of an experimental apparatus to generate mercury vapors at a constant rate and modifying the existing non-thermal plasma reactor system, (2) solving the analytical challenge for measuring mercury vapor concentration at ppb level, and (3) conducting experiments on mercury oxidation under plasma conditions to establish proof of concept.

  16. Dynamic Strain on Thin Diaphragms of a Mercury Target During 800-MeV Proton Thermal Shock Tests

    SciTech Connect

    Allison, S.W.; Andriulli, J.B.; Cates, M.R.; Earl, D.D.; Haines, J.R.; Morrissey, F.X.; Tsai, C.C.; Wender, S.

    1999-11-13

    Extrinsic Fabry-Perot Interferometric fiber optic sensors were used to measure dynamic strains on thin diaphragms of a liquid mercury target, which was subjected to intense 800-MeV proton thermal shock tests. The mercury target is engineered with very thin end plates or diaphragms (either 0.6 mm or 1.9 mm) for studying large strain effects. During thermal shock tests, the mercury in the target interacted with an intense pulsed beam of 2.4x10{sup 13 protons}. The resulting pressure waves lead to large strains exceeding 250 microstrains on a 0.6-mm diaphragm. Significant factors relative to the accuracy of strain measurements are emphasized, such as the sensor air gap, alignment of sensors, and frequency response of the strain instrument. In this paper, dynamic strains measured on thin diaphragms are described and discussed.

  17. Martensitic/ferritic steels as container materials for liquid mercury target of ESS

    SciTech Connect

    Dai, Y.

    1996-06-01

    In the previous report, the suitability of steels as the ESS liquid mercury target container material was discussed on the basis of the existing database on conventional austenitic and martensitic/ferritic steels, especially on their representatives, solution annealed 316 stainless steel (SA 316) and Sandvik HT-9 martensitic steel (HT-9). Compared to solution annealed austenitic stainless steels, martensitic/ferritic steels have superior properties in terms of strength, thermal conductivity, thermal expansion, mercury corrosion resistance, void swelling and irradiation creep resistance. The main limitation for conventional martensitic/ferritic steels (CMFS) is embrittlement after low temperature ({le}380{degrees}C) irradiation. The ductile-brittle transition temperature (DBTT) can increase as much as 250 to 300{degrees}C and the upper-shelf energy (USE), at the same time, reduce more than 50%. This makes the application temperature range of CMFS is likely between 300{degrees}C to 500{degrees}C. For the present target design concept, the temperature at the container will be likely controlled in a temperature range between 180{degrees}C to 330{degrees}C. Hence, CMFS seem to be difficult to apply. However, solution annealed austenitic stainless steels are also difficult to apply as the maximum stress level at the container will be higher than the design stress. The solution to the problem is very likely to use advanced low-activation martensitic/ferritic steels (LAMS) developed by the fusion materials community though the present database on the materials is still very limited.

  18. Elemental mercury removals observed in a laboratory-scale wet FGD scrubber system

    SciTech Connect

    Mendelsohn, M.H.; Wu, J.; Huang, H.; Livengood, C.D.

    1994-08-01

    Published data are limited regarding gaseous mercury removal in wet scrubber flue-gas desulfurization (FGD) systems. The data that do exist show a wide variation in reported mercury removals, from about 5 to 95%. We have performed tests for the removal of gaseous elemental mercury in a well-controlled laboratory environment by using both conventional and modified configurations of an aqueous scrubber system. Results from these tests strongly suggest that the removal of elemental mercury in a wet scrubber system is controlled by liquid-film resistance. Our results have also led us to hypothesize that the mercury-containing species in a flue-gas stream consist of only two types: elemental mercury and oxidized mercury compounds. We further assert that the differences observed in mercury removal reflect different proportions of each of these two types of mercury-containing species. We suggest that the total mercury removal will be high when the actual, but unmeasured, proportion of oxidized mercury compounds is high.

  19. Mercury toxicity. Agency for Toxic Substance and Disease Registry

    SciTech Connect

    Not Available

    1992-12-01

    Because mercury has several forms and because it produces subtle effects at chronic low-level exposures, mercury toxicity can be a difficult diagnosis to establish. Elemental mercury vapor accounts for most occupational and many accidental exposures. The main source of organic methyl mercury exposure in the general population is fish consumption. Children are at increased risk of exposure to elemental mercury vapor in the home because it tends to settle to the floor. The chemical and physical forms of mercury determine its absorption, metabolism, distribution and excretion pathways. The central nervous system and kidneys are key targets of mercury toxicity. Chelation therapy has been used successfully in treating patients who have ingested mercury salts or inhaled elemental mercury. There is no antidote for patients poisoned with organic mercury.7 references.

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

    SciTech Connect

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

    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.

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

    PubMed

    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. PMID:26845366

  2. 8-cm mercury ion thruster system technology

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The technology status of 8-cm diameter electron bombardment ion thrusters is presented. Much of the technology resulting from the 5-cm diameter thruster has been adapted and improved upon to increase the reliability, durability, and efficiency of the 8-cm thruster. Technology discussed includes: dependence of neutralizer tip erosion upon neutralizer flow rate; impregnated and rolled-foil insert cathode performance and life testing; neutralizer position studies; thruster ion beam profile measurements; high voltage pulse ignition; high utilization ion machined accelerator grids; deposition internal and external to the thruster; thruster vectoring systems; thruster cycling life testing and thruster system weights for typical mission applications.

  3. Using Wet-FGD systems for mercury removal.

    PubMed

    Díaz-Somoano, Mercedes; Unterberger, Sven; Hein, Klaus R G

    2005-09-01

    A plan to control mercury emissions to the atmosphere and to establish mercury emission limits has recently been elaborated by the European Commission, making it necessary to devise an efficient and cost effective mercury removal technology. Towards this end wet flue gas desulfurization units appear as a promising option for multi-pollutant control. However, more investigation on mercury removal and a greater mercury removal efficiency are required to achieve this objective. In the present work scrubber chemistry and the application of various solid additives to enhance mercury removal in wet scrubbers is evaluated. The results obtained show a significant correlation between mercury removal efficiency and the pH of the scrubber slurry and SO2 concentration. A weaker correlation was observed between oxygen or slurry concentration and removal efficiency. Finally several solid oxides were found to be effective additives for enhancing mercury capture in wet scrubbers. PMID:16121271

  4. ENHANCED CONTROL OF MERCURY BY WET FLUE GAS DESULFURIZATION SYSTEMS

    SciTech Connect

    G. Blythe; B. Marsh; S. Miller; C. Richardson; M. Richardson

    2001-06-01

    The U.S. Department of Energy and EPRI have co-funded this project to improve the control of mercury emissions from coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems. The project investigated catalytic oxidation of vapor-phase elemental mercury to a form that is more effectively captured in wet FGD systems. If successfully developed, the process could be applicable to over 90,000 MW of utility generating capacity with existing FGD systems and to future FGD installations. Field tests have been conducted to determine whether candidate catalyst materials remain active towards mercury oxidation after extended flue gas exposure. Catalyst life will have a large impact on the cost effectiveness of this potential process. A mobile catalyst test unit has been used to test the activity of four different catalyst materials for a period of up to six months at each of three utility sites. Catalyst testing was completed at the first site, which fires Texas lignite, in December 1998 and at the second test site, which fires a Powder River Basin subbituminous coal in the fall of 1999. Testing at the third site, which fires a medium- to high-sulfur bituminous coal, began in June 2000 and was completed at the end of January 2001. This Topical Reports includes results from Site 3; results from Sites 1 and 2 were reported previously. At Site 3, catalysts were tested in two forms, including powders dispersed in sand bed reactors and in a commercially available form as a coated honeycomb structure. Field testing has been supported by laboratory tests to screen catalysts for activity at specific flue gas compositions, to investigate catalyst deactivation mechanisms and methods for regenerating spent catalysts. Laboratory results related to the Site 3 field effort are also included and discussed in this Topical Report.

  5. ENHANCED CONTROL OF MERCURY BY WET FLUE GAS DESULFURIZATION SYSTEMS

    SciTech Connect

    Unknown

    2001-06-01

    The U.S. Department of Energy and EPRI co-funded this project to improve the control of mercury emissions from coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems. The project has investigated catalytic oxidation of vapor-phase elemental mercury to a form that is more effectively captured in wet FGD systems. If successfully developed, the process could be applicable to over 90,000 MW of utility generating capacity with existing FGD systems, and to future FGD installations. Field tests were conducted to determine whether candidate catalyst materials remain active towards mercury oxidation after extended flue gas exposure. Catalyst life will have a large impact on the cost effectiveness of this potential process. A mobile catalyst test unit was used to test the activity of four different catalyst materials for a period of up to six months each at three utility sites. Catalyst testing was completed at the first site, which fires Texas lignite, in December 1998; at the second test site, which fires a Powder River Basin subbituminous coal, in November 1999; and at the third site, which fires a medium- to high-sulfur bituminous coal, in January 2001. Results of testing at each of the three sites were reported in previous technical notes. At Site 1, catalysts were tested only as powders dispersed in sand bed reactors. At Sites 2 and 3, catalysts were tested in two forms, including powders dispersed in sand and in commercially available forms such as extruded pellets and coated honeycomb structures. This final report summarizes and presents results from all three sites, for the various catalyst forms tested. Field testing was supported by laboratory tests to screen catalysts for activity at specific flue gas compositions, to investigate catalyst deactivation mechanisms and methods for regenerating spent catalysts. Laboratory results are also summarized and discussed in this report.

  6. Assessment of mercury presence and exposure in a lighthouse with a mercury drive system

    SciTech Connect

    van Netten, C.; Teschke, K.E.

    1988-02-01

    It is common practice for lighthouses with large Fresnel lenses to use mercury baths as a low-friction rotation mechanism. Some recent acute mercury poisonings and incidents of abnormal behavior in lighthouse keepers have drawn attention to the potential for chronic mercury poisoning in these workplaces. This study evaluated the distribution of mercury in a lighthouse on the Canadian west coast, and the exposure of its keepers and their spouses under two weather conditions. The urine mercury levels found in the lighthouse personnel were all less than would be expected in an occupationally exposed group (<4 ..mu..g/24 hr urine). Air concentrations in the lighthouse ranged from 4.4 to 26.3 ..mu..g/m/sup 3/. Swabbing showed considerable accumulation of mercury on surfaces in the area of the light rotation mechanism, as well as transport throughout the lighthouse. The mercury levels in this lighthouse appeared to be under control through effective convective ventilation and employee awareness. The study signals potential problems where precautions have not been taken, especially in situations where the keepers an their families live in the lighthouse.

  7. Measurement of Dynamic Strain on a Mercury Target Vessel During 800-MeV Proton Thermal Shock Tests

    SciTech Connect

    Cates, M.R.

    2001-01-11

    A mercury target vessel, designed to simulate some aspects of the eventual target design for the proposed Spallation Neutron Source (SNS) to be built in Oak Ridge by the Department of Energy, was used in a test at the Los Alamos Neutron Science Center (LANSCE) to study the strain induced from thermal shock of bombarding protons. In the SNS, intense thermal shock loads are expected to cause an enormous rate of temperature rise ({approximately}10{sup 7} K/s), with resulting pressure waves in the mercury that may lead to large stresses on the thin walls of the mercury target. To guide the mercury target design and to benchmark the computer design codes, transient strain was measured using fiber optic Fabry-Perot sensors. Twenty strain sensors were attached in various axial and transverse orientations to a cylindrical stainless steel target vessel containing mercury. The vessel was 10 cm in diameter, about 15 cm long, and with a 5-cm radius hemispherical shell welded to the forward end. The test was done at the LANSCE Weapons Neutron Research (WNR) beam facility on 30-31 January 1999. The sensors were attached with gauge lengths of about two centimeters, and were located in pairs in most areas, for redundancy and facilitation of data analysis. The 800-MeV proton deposition of 0.5--2.3 x 10{sup 13} over a full-width at half maximum beam size of {approximately}25 mm, produced axial strains peaking at a few microstrains, with transverse (hoop) strains more than an order of magnitude higher. We describe the experiments, including the sensors and measurement configuration, and discuss the strain data analysis.

  8. The MESSENGER Earth Flyby: Results from the Mercury Dual Imaging System

    NASA Astrophysics Data System (ADS)

    Prockter, L. M.; Murchie, S. L.; Hawkins, S. E.; Robinson, M. S.; Shelton, R. G.; Vaughan, R. M.; Solomon, S. C.

    2005-12-01

    The MESSENGER (MErcury Surface, Space ENvironment, Geochemistry, and Ranging) spacecraft was launched from Cape Canaveral Air Force Station, Fla., on 3 August 2004. It returned to Earth for a gravity assist on 2 August 2005, providing an exceptional opportunity for the Science Team to perform instrument calibrations and to test some of the data acquisition sequences that will be used to meet Mercury science goals. The Mercury Dual Imaging System (MDIS), one of seven science instruments on MESSENGER, consists of a wide-angle and a narrow-angle imager that together can map landforms, track variations in surface color, and carry out stereogrammetry. The two imagers are mounted on a pivot platform that enables the instrument to point in a different direction from the spacecraft boresight, allowing great flexibility and increased imaging coverage. During the week prior to the closest approach to Earth, MDIS acquired a number of images of the Moon for radiometric calibration and to test optical navigation sequences that will be used to target planetary flybys. Twenty-four hours before closest approach, images of the Earth were acquired with 11 filters of the wide-angle camera. After MDIS flew over the nightside of the Earth, additional color images centered on South America were obtained at sufficiently high resolution to discriminate small-scale features such as the Amazon River and Lake Titicaca. During its departure from Earth, MDIS acquired a sequence of images taken in three filters every 4 minutes over a period of 24 hours. These images have been assembled into a movie of a crescent Earth that begins as South America slides across the terminator into darkness and continues for one full Earth rotation. This movie and the other images have provided a successful test of the sequences that will be used during the MESSENGER Mercury flybys in 2008 and 2009 and have demonstrated the high quality of the MDIS wide-angle camera.

  9. AUTOMATIC INTERFACING SYSTEM FOR SAMPLING TOTAL MERCURY IN STATIONARY SOURCE EMISSIONS

    EPA Science Inventory

    An interfacing system to sample total mercury emissions in source streams and suitably condition, dilute, and transport the sample to a mercury measuring instrument was designed, fabricated, and tested. The system consists of three components: a conditioner, a diluter, and a pump...

  10. Aided targeting system simulation evaluation

    NASA Technical Reports Server (NTRS)

    Demaio, Joe; Becker, Curtis

    1994-01-01

    Simulation research was conducted at the Crew Station Research and Development Facility on the effectiveness and ease of use of three targeting systems. A manual system required the aviator to scan a target array area with a simulated second generation forward looking infrared (FLIR) sensor, locate and categorize targets, and construct a target hand-off list. The interface between the aviator and the system was like that of an advanced scout helicopter (manual mode). Two aided systems detected and categorized targets automatically. One system used only the FLIR sensor and the second used FLIR fused with Longbow radar. The interface for both was like that of an advanced scout helicopter aided mode. Exposure time while performing the task was reduced substantially with the aided systems, with no loss of target hand-off list accuracy. The fused sensor system showed lower time to construct the target hand-off list and a slightly lower false alarm rate than the other systems. A number of issues regarding system sensitivity and criterion, and operator interface design are discussed.

  11. EVALUATION OF MERCURY EMISSIONS FROM COAL-FIRED FACILITIES WITH SCR AND FGD SYSTEMS

    SciTech Connect

    J.A. Withum; S.C. Tseng; J.E. Locke

    2005-11-01

    CONSOL Energy Inc., Research & Development (CONSOL), with support from the U.S. Department of Energy, National Energy Technology Laboratory (DOE) and the Electric Power Research Institute (EPRI), is evaluating the effects of selective catalytic reduction (SCR) on mercury (Hg) capture in coal-fired plants equipped with an electrostatic precipitator (ESP)--wet flue gas desulfurization (FGD) combination or a spray dryer absorber--fabric filter (SDA-FF) combination. In this program CONSOL is determining mercury speciation and removal at 10 coal-fired facilities. The objectives are (1) to evaluate the effect of SCR on mercury capture in the ESP-FGD and SDA-FF combinations at coal-fired power plants, (2) evaluate the effect of catalyst degradation on mercury capture; (3) evaluate the effect of low load operation on mercury capture in an SCR-FGD system, and (4) collect data that could provide the basis for fundamental scientific insights into the nature of mercury chemistry in flue gas, the catalytic effect of SCR systems on mercury speciation and the efficacy of different FGD technologies for mercury capture. This document, the seventh in a series of topical reports, describes the results and analysis of mercury sampling performed on a 1,300 MW unit burning a bituminous coal containing three percent sulfur. The unit was equipped with an ESP and a limestone-based wet FGD to control particulate and SO2 emissions, respectively. At the time of sampling an SCR was not installed on this unit. Four sampling tests were performed in September 2003. Flue gas mercury speciation and concentrations were determined at the ESP outlet (FGD inlet), and at the stack (FGD outlet) using the Ontario Hydro method. Process stream samples for a mercury balance were collected to coincide with the flue gas measurements. The results show that the FGD inlet flue gas oxidized:elemental mercury ratio was roughly 2:1, with 66% oxidized mercury and 34% elemental mercury. Mercury removal, on a coal

  12. Complex history of the Rembrandt basin and scarp system, Mercury

    NASA Astrophysics Data System (ADS)

    Ferrari, S.; Massironi, M.; Klimczak, C.; Byrne, P. K.; Cremonese, G.; Solomon, S. C.

    2012-09-01

    During its second and third flybys, the MESSENGER spacecraft [1] imaged the wellpreserved Rembrandt basin in Mercury's southern hemisphere. With a diameter of 715 km, Rembrandt is the second largest impact structure recognized on Mercury after the 1550-km-diameter Caloris basin. Rembrandt is also one of the youngest major basins [2] and formed near the end of the Late Heavy Bombardment (~3.8 Ga). Much of the basin interior has been resurfaced by smooth, high-reflectance units interpreted to be of volcanic origin [3]. These units host sets of contractional and extensional landforms generally oriented in directions radial or concentric to the basin, similar to those observed within the Caloris basin [4-6]; these structures are probably products of multiple episodes of deformation [2,7,8]. Of particular note in the Rembrandt area is a 1,000-km-long reverse fault system [9] that cuts the basin at its western rim and bends eastward toward the north, tapering into the impact material. On the basis of its shape, the structure has previously been characterized as a lobate scarp. Its formation and localization have been attributed to the global contraction of Mercury [2]. From MESSENGER flyby and orbital images, we have identified previously unrecognized kinematic indicators of strike-slip motion along the Rembrandt scarp, together with evidence of interaction between the scarp orientation and the concentric basin-related structural pattern described above. Here we show through cross-cutting relationships and scarp morphology that the development of the Rembrandt scarp was strongly influenced by tectonics related to basin formation and evolution.

  13. Got Mercury?

    NASA Technical Reports Server (NTRS)

    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

  14. Thermal-hydraulic analysis of the liquid mercury target for the national spallation neutron source

    SciTech Connect

    Siman-Tov, M.; Wendel, M.W.; Haines, J.R.; Rogers, M.

    1997-04-01

    The National Spallation Neutron Source (NSNS) is a high-energy, accelerator-based spallation neutron source being designed by a multi-laboratory team led by Oak Ridge National Laboratory (ORNL) to achieve very high fluxes of neutrons for scientific experiments. The NSNS is proposed to have a 1 MW beam of high-energy ({approximately}1 GeV) protons upgradable to 5 MW and operating at 60 Hz with a pulse duration of 0.5 {mu}s. Peak steady-state power density in the target is about 640 MW/m{sup 3} for 1 MW, whereas the pulse instantaneous peak power density is as high as 22,000 GW/m{sup 3}. The local peak temperature rise for a single pulse over it`s time-averaged value is only 6{degrees}C, but the rate of this temperature rise during the pulse is extremely fast ({approximately}12 million {degrees}C/s). In addition to the resulting thermal shock and materials compatibility concerns, key feasibility issues for the target are related to its thermal-hydraulic performance. These include proper flow distribution, flow reversals and stagnation zones, possible {open_quotes}hot spots{close_quotes}, cooling of the beam {open_quotes}window{close_quotes}, and the challenge of mitigating the effects of thermal shock through possible injection of helium bubbles. An analytic approach was used on the PC spreadsheet EXCEL to evaluate target design options and to determine the global T/H parameters in the current concept. The general computational fluid dynamics (CFD) code CFX was used to simulate the detailed time-averaged two-dimensional thermal and flow distributions in the liquid mercury. In this paper, an overview of the project and the results of this preliminary work are presented. Heat transfer characteristics of liquid mercury under wetting and non-wetting conditions are discussed, and future directions of the program in T/H analysis and R&D are outlined.

  15. Mercury's South Polar Region

    NASA Video Gallery

    This animation shows 89 wide-angle camera (WAC) images of Mercury’s south polar region acquired by the Mercury Dual Imaging System (MDIS) over one complete Mercury solar day (176 Earth days). Thi...

  16. Gigacycle fatigue behaviour of austenitic stainless steels used for mercury target vessels

    NASA Astrophysics Data System (ADS)

    Naoe, Takashi; Xiong, Zhihong; Futakawa, Masatoshi

    2016-01-01

    A mercury enclosure vessel for the pulsed spallation neutron source manufactured from a type 316L austenitic stainless steel, a so-called target vessel, suffers the cyclic loading caused by the proton beam induced pressure waves. A design criteria of the JSNS target vessel which is defined based on the irradiation damage is 2500 h at 1 MW with a repetition rate of 25 Hz, that is, the target vessel suffers approximately 109 cyclic loading while in operation. Furthermore, strain rate of the beam window of the target vessel reaches 50 s-1 at the maximum, which is much higher than that of the conventional fatigue. Gigacycle fatigue strength up to 109 cycles for solution annealed 316L (SA) and cold-worked 316L (CW) were investigated through the ultrasonic fatigue tests. Fatigue tests were performed under room temperature and 250 °C which is the maximum temperature evaluated at the beam window in order to investigate the effect of temperature on fatigue strength of SA and CW 316L. The results showed that the fatigue strength at 250 °C is clearly reduced in comparison with room temperature, regardless of cold work level. In addition, residual strength and microhardness of the fatigue tested specimen were measured to investigate the change in mechanical properties by cyclic loading. Cyclic hardening was observed in both the SA and CW 316L, and cyclic softening was observed in the initial stage of cyclic loading in CW 316L. Furthermore, abrupt temperature rising just before fatigue failure was observed regardless of testing conditions.

  17. Kuramoto transition in an ensemble of mercury beating heart systems.

    PubMed

    Verma, Dinesh Kumar; Singh, Harpartap; Parmananda, P; Contractor, A Q; Rivera, M

    2015-06-01

    We have studied, experimentally, the collective behavior of the electrically coupled autonomous Mercury Beating Heart (MBH) systems exhibiting the breathing mode, by varying both the coupling strength and the population size (from N = 3 to N = 16). For a fixed N, the electrical and the mechanical activities of the MBH systems achieve complete synchronization at different coupling strengths. The electrical activity of each MBH system is measured by the corresponding electrode potential (Ei = Vi). Additionally, the mechanical activity of each MBH oscillator is visually observed (snapshots and video clips). Subsequently, this activity is quantified by calculating the temporal variation in the area (Ai) of the Hg drop. As a result, the synchronization of the electrical (Ei = Vi) and the mechanical (Ai) activities can be measured. The extent of synchronization was quantified by employing the order parameter (r). Our experimental results are found to be in agreement with the Kuramoto theory. PMID:26117134

  18. Public health consequences of mercury spills: Hazardous Substances Emergency Events Surveillance system, 1993-1998.

    PubMed Central

    Zeitz, Perri; Orr, Maureen F; Kaye, Wendy E

    2002-01-01

    We analyzed data from states that participated in the Hazardous Substances Emergency Events Surveillance (HSEES) system maintained by the Agency for Toxic Substances and Disease Registry to describe the public health consequences of mercury releases. From 1993 through 1998, HSEES captured 406 events in which mercury was the only substance released. Schools and universities, private residences, and health care facilities were the most frequent locations involved in mercury events, and human error was the contributing factor for most of the releases. Fourteen persons experienced adverse health effects as a result of the releases. An additional 31 persons had documented elevated levels of mercury in the blood. No fatalities resulted. Evacuations were ordered in 90 (22%) of the events, and the length of evacuation ranged from 1 hr to 46 days. Mercury spills have a significant public health impact and economic burden. Some actions that could potentially lessen the consequences of mercury spills are to switch to mercury-free alternatives, train people in the safe handling and disposal of mercury, and keep mercury securely stored when it is necessary to have it on hand. PMID:11836139

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

    PubMed

    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. PMID:25324429

  20. Guidance system for laser targets

    DOEpatents

    Porter, Gary D.; Bogdanoff, Anatoly

    1978-01-01

    A system for guiding charged laser targets to a predetermined focal spot of a laser along generally arbitrary, and especially horizontal, directions which comprises a series of electrostatic sensors which provide inputs to a computer for real time calculation of position, velocity, and direction of the target along an initial injection trajectory, and a set of electrostatic deflection means, energized according to a calculated output of said computer, to change the target trajectory to intercept the focal spot of the laser which is triggered so as to illuminate the target of the focal spot.

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

    USGS Publications Warehouse

    Kolker, A.; Senior, C.L.; Quick, J.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. ?? 2006 Elsevier Ltd. All rights reserved.

  2. COLLECTION EFFICIENCY EVALUATION OF MERCURY-TRAPPING MEDIA FOR THE SASS TRAIN IMPINGER SYSTEM

    EPA Science Inventory

    The report gives results of an investigation of the collection efficiencies of the popularly used media in the SASS train impinger assembly. A simple mercury-vapor generator system, based on saturation of air with mercury vapor at a fixed temperature, was assembled. Performance e...

  3. A tool for assessing mercury loadings from restored tidal systems

    USGS Publications Warehouse

    Fleck, J.A.; Bergamaschi, B.A.; Downing, B.D.; Lionberger, M.A.; Schoellhamer, D.H.; Boss, E.; Stephenson, M.

    2006-01-01

    Accurately quantifying net loads in tidal systems is difficult owing to the high variability in constituent concentrations over the vastly different time scales present in these systems. Perhaps most difficult is the measurement of fluxed over the tidal time scale. On this scale, the net export of the constituent is orders of magnitude less than the bulk exchange in either direction because of the vast quantities of water that are exchanged. Therefore, numerous measurements are required in a brief amount of time to accurately quantify constituent fluxes between a tidal wetland and its surrounding waters. These complications with sampling are exacerbated for mercury species because of the difficulties is to develop surrogates that may be measured in situ and which may be used for interpolating and extrapolating from discrete measurements over a number of tidal cycles and a range of conditions.  

  4. Status of R&D on mitigating the effects of pressure waves for the Spallation Neutron Source mercury target

    NASA Astrophysics Data System (ADS)

    Riemer, Bernard W.; Wendel, Mark W.; Felde, David K.; Abdou, Ashraf A.; McClintock, David A.

    2012-12-01

    The Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory has been conducting R&D on mitigating the effects of pressure waves in mercury spallation targets since 2001. More precisely, cavitation damage of the target vessel caused by the short beam pulse threatens to limit its lifetime more severely than radiation damage as well as limit its ultimate power capacity - and hence its neutron intensity performance. The R&D program has moved from verification of the beam-induced damage phenomena to study of material and surface treatments for damage resistance to the current emphasis on gas injection techniques for damage mitigation. Two techniques are being worked on: injection of small dispersed gas bubbles that mitigate the pressure waves volumetrically; and protective gas walls that isolate the vessel from the damaging effects of collapsing cavitation bubbles. The latter has demonstrated good damage mitigation during in-beam testing with limited pulses, and adequate gas wall coverage at the beam entrance window has been demonstrated with the SNS mercury target flow configuration using a full scale mercury test loop. A question on the required area coverage remains which depends on results from SNS target post irradiation examination. The small gas bubble technique has been less effective during past in-beam tests but those results were with un-optimized and un-verified bubble populations. Another round of in-beam tests with small gas bubbles is planned for 2011. The first SNS target was removed from service in mid 2009 and samples were cut from two locations at the target's beam entrance window. Through-wall damage was observed at the innermost mercury vessel wall (not a containment wall). The damage pattern suggested correlation with the local mercury flow condition which is nearly stagnant at the peak damage location. Detailed post irradiation examination of the samples is under way that will assess the erosion and measure irradiation-induced changes

  5. Status of R&D on Mitigating the Effects of Pressure Waves for the Spallation Neutron Source Mercury Target

    SciTech Connect

    Riemer, Bernie; Wendel, Mark W; Felde, David K; Abdou, Ashraf A; McClintock, David A

    2012-01-01

    The Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory has been conducting R&D on mitigating the effects of pressure waves in mercury spallation targets since 2001. More precisely, cavitation damage of the target vessel caused by the short beam pulse threatens to limit its lifetime more severely than radiation damage as well as limit its ultimate power capacity and hence its neutron intensity performance. The R&D program has moved from verification of the beam-induced damage phenomena to study of material and surface treatments for damage resistance to the current emphasis on gas injection techniques for damage mitigation. Two techniques are being worked on: injection of small dispersed gas bubbles that mitigate the pressure waves volumetrically; and protective gas walls that isolate the vessel from the damaging effects of collapsing cavitation bubbles. The latter has demonstrated good damage mitigation during in-beam testing with limited pulses, and adequate gas wall coverage at the beam entrance window has been demonstrated with the SNS mercury target flow configuration using a full scale mercury test loop. A question on the required area coverage remains which depends on results from SNS target post irradiation examination. The small gas bubble technique has been less effective during past in-beam tests but those results were with un-optimized and un-verified bubble populations. Another round of in-beam tests with small gas bubbles is planned for 2011. The first SNS target was removed from service in mid 2009 and samples were cut from two locations at the target s beam entrance window. Through-wall damage was observed at the innermost mercury vessel wall (not a containment wall). The damage pattern suggested correlation with the local mercury flow condition which is nearly stagnant at the peak damage location. Detailed post irradiation examination of the samples is under way that will assess the erosion and measure irradiation-induced changes

  6. Laser fusion target illumination system.

    PubMed

    Thomas, C E

    1975-06-01

    Laser fusion experiments require the focusing of very intense pulsed laser beams onto very small fuel pellets. All reported experiments to date have used lenses to focus one or more laser beams onto the target. This paper describes a combined refractive/reflective illumination system that provides nearly uniform irradiance with nearly orthogonal incidence over the complete spherical target, with only two laser beams. This illumination system was used in the experiments that produced the first known symmetric target implosions. Furthermore, these experiments produced what we believe were the first thermonuclear neutrons generated by a laser-driven implosion. PMID:20154815

  7. A Proof-of-Principal Experiment for a High-Power Target System

    SciTech Connect

    Kirk,H.G.; Samulyak, R.; Simos, N.; Tsang, T.; Efthymiopoulos, I.; Fabich, A.; Haseroth, H.; Haug, F.; Lettry, J.; Graves, V. B.; Spampinato, P. T.; McDonald, K. T.; Bennett, J. R. J.; Edgecock, T. R.

    2006-06-26

    The MERIT experiment, to be run at CERN in 2007, is a proof-of-principle test for a target system that converts a 4-MW proton beam into a high-intensity muon beam for either a neutrino factory complex or a muon collider. The target system is based on a free mercury jet that intercepts an intense proton beam inside a 15-T solenoidal magnetic field. A muon collider or neutrino factory requires intense beams of muons, which are obtained from the decay of pions. Pion production by a proton beam is maximized by use of a high-Z target such as mercury. A liquid jet target has the advantages over a solid target that a flowing jet can readily remove heat and that it is immune to radiation damage. However the proton beam energy disrupts the jet and the system could be operationally unstable. Efficient capture of low-energy secondary pions (for transfer into the subsequent muon accelerator complex) requires that the target system be immersed in a strong magnetic field of solenoidal geometry. This magnetic field should stabilize the mercury flow in regions of nearly uniform field, but it perturbs the liquid metal jet as it enters the field. Hence, the behavior of the mercury jet plus an intense proton beam inside a strong magnetic field needs to be understood better before resources are committed to a larger facility. The MERIT experiment is to be conducted at CERN in 2007 for this purpose.

  8. Evaluation of Mercury Emissions from Coal-Fired Facilities with SCR and FGD Systems

    SciTech Connect

    J. A. Withum; S. C. Tseng; J. E. Locke

    2006-01-31

    CONSOL Energy Inc., Research & Development (CONSOL), with support from the U.S. Department of Energy, National Energy Technology Laboratory (DOE) and the Electric Power Research Institute (EPRI), is evaluating the effects of selective catalytic reduction (SCR) on mercury (Hg) capture in coal-fired plants equipped with an electrostatic precipitator (ESP)--wet flue gas desulfurization (FGD) combination or a spray dyer absorber--fabric filter (SDA-FF) combination. In this program CONSOL is determining mercury speciation and removal at 10 coal-fired facilities. The principal purpose of this work is to develop a better understanding of the potential mercury removal ''co-benefits'' achieved by NO{sub x}, and SO{sub 2} control technologies. It is expected that these data will provide the basis for fundamental scientific insights into the nature of mercury chemistry in flue gas, the catalytic effect of SCR systems on mercury speciation and the efficacy of different FGD technologies for mercury capture. Ultimately, this insight could help to design and operate SCR and FGD systems to maximize mercury removal. The objectives are (1) to evaluate the effect of SCR on mercury capture in the ESP-FGD and SDA-FF combinations at coal-fired power plants, (2) evaluate the effect of SCR catalyst degradation on mercury capture; (3) evaluate the effect of low load operation on mercury capture in an SCR-FGD system, and (4) collect data that could provide the basis for fundamental scientific insights into the nature of mercury chemistry in flue gas, the catalytic effect of SCR systems on mercury speciation and the efficacy of different FGD technologies for mercury capture. This document, the ninth in a series of topical reports, describes the results and analysis of mercury sampling performed on Unit 1 at Plant 7, a 566 MW unit burning a bituminous coal containing 3.6% sulfur. The unit is equipped with a SCR, ESP, and wet FGD to control NO{sub x}, particulate, and SO{sub 2} emissions

  9. Dynamic Pressure of Liquid Mercury Target During 800-MeV Proton Thermal Shock Tests

    SciTech Connect

    Allison, S.W.; Andriulli, J.B.; Cates, M.R.; Earl. D.D.; Haines, J.R.; Morrissey, F.X.; Tsai, C.C.; Wender, S.

    2000-02-01

    Described here are efforts to diagnose transient pressures generated by a short-pulse (about 0.5 microseconds) high intensity proton ({approximately} 2 * 10 14 per pulse) beam. Proton energy is 800-MeV. The tests were performed at the Los Alamos Neutron Science Center - Weapons Neutron Research (LANSCE-WNR). Such capability is required for understanding target interaction for the Spallation Neutron Source project as described previously at this conference.1-4 The main approach to effect the pressure measurements utilized the deflection of a diaphragm in intimate contact with the mercury. There are a wide variety of diaphragm-deflection methods used in scientific and industrial applications. Many deflection-sensing approaches are typically used, including, for instance, capacitive and optical fiber techniques. It was found, however, that conventional pressure measurement using commercial pressure gages with electrical leads was not possible due to the intense nuclear radiation enviro nment. Earlier work with a fiber optic strain gauge demonstrated the viability of using fiber optics for this environment.

  10. Mercury re-emission in flue gas multipollutants simultaneous absorption system.

    PubMed

    Liu, Yue; Wang, Qingfeng; Mei, Rongjun; Wang, Haiqiang; Weng, Xiaole; Wu, Zhongbiao

    2014-12-01

    Recently, simultaneous removal of SO2, NOx and oxidized mercury in wet flue gas desulfurization (WFGD) scrubber has become a research focus. Mercury re-emission in traditional WFGD system has been widely reported due to the reduction of oxidized mercury by sulfite ions. However, in multipollutants simultaneous absorption system, the formation of a large quantity of nitrate and nitrite ions as NOx absorption might also affect the reduction of oxidized mercury in the aqueous absorbent. As such, this paper studied the effects of nitrate and nitrite ions on mercury re-emission and its related mechanism. Experimental results revealed that the nitrate ions had neglected effect on mercury re-emission while the nitrite ions could greatly change the mercury re-emission behaviors. The nitrite ions could initially improve the Hg(0)-emission through the decomposition of HgSO3NO2(-), but with a further increase in the concentration, they would then inhibit the reduction of bivalent mercury owing to the formation of Hg-nitrite complex [Hg(NO2)x(2-x)]. In addition, the subsequent addition of Cl(-) could further suppress the Hg(0) emission, where the formation of a stable Hg-SO3-NO2-Cl complex was assumed to be the main reason for such strong inhibition effect. PMID:25360573

  11. COMPARISON OF MERCURY BLOOD PRESSURE READINGS TO OSCILLOMETRIC AND CENTRAL BLOOD PRESSURE IN PREDICTING TARGET ORGAN DAMAGE IN YOUTH

    PubMed Central

    Urbina, Elaine M; Khoury, Philip R; McCoy, Connie E; Daniels, Stephen R; Dolan, Lawrence M; Kimball, Thomas R

    2015-01-01

    Objective Hypertension (HT) is an important risk factor for target organ damage (TOD). New methods for measuring BP are replacing mercury sphygmomanometry in many clinics. We examined the utility of different BP measurement techniques in predicting subclinical TOD in adolescents and young adults. Methods Subjects in a study of the CV effects of obesity and type 2 diabetes (T2DM) were evaluated (N=677, 18 ± 3.3 years, 35% male, 60% non-Caucasian, 30% T2DM). We measured adiposity, lab, left ventricular mass, carotid intima-media thickness & pulse wave. BP was measured 3 times with mercury sphygmomanometery (BPm) an oscillometric device (BPo) and central aortic BP (BPc) was derived with arterial tonometry. Subjects were stratified as normotensive (N), pre-hypertensive (P) or hypertensive (H). Results The prevalence of HT this cohort with mean BMI of 31 was highest with BPo (16%), followed by BPm (11%) and BPc (9%), p≤0.001. BPm was most consistent in differentiating left ventricular mass and pulse wave velocity among subjects in the P group as compared to the N & H groups. Mercury BP was also more sensitive and specific in predicting greater left ventricular mass, pulse wave velocity and carotid thickness than the other BP measurement techniques in logistic regression. Conclusions We conclude that mercury sphygmomanometry should remain the gold standard for evaluation of HT and the risk for TOD in adolescents and young adults. PMID:25647284

  12. Mass-Independent Fractionation of Mercury in Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Sherman, L. S.; Blum, J. D.; Nordstrom, D. K.; McCleskey, R. B.; Barkay, T.; Vetriani, C.

    2008-12-01

    Experimental results indicate that mass-independent fractionation (MIF) of mercury occurs during both photochemical reduction of Hg2+ and photochemical demethylation of methyl-mercury. In aqueous systems, the photochemical reduction of Hg2+aq to Hg0aq and subsequent evasion of Hg0g preferentially retains the odd mass isotopes of Hg in the aqueous phase and releases the even mass isotopes of Hg in Hg0g. MIF of Hg has been observed recently in marine and freshwater fish, soils, peat, mosses and sediments. We investigated Hg in modern volcanic-hydrothermal systems to evaluate whether major earth reservoirs carry a MIF signature. Hydrothermal systems driven by mantle-derived volcanism are a major natural source of Hg to the atmosphere and may represent the isotopic composition of deep geological reservoirs. We analyzed fluid and siliceous sinter samples from hot springs in the Yellowstone Plateau volcanic field and vent chimney precipitates from the Guaymas Basin sea-floor rift. In all of the analyzed fluid and sinter samples from Ojo Caliente hot spring in Yellowstone, we observed a small but significant positive MIF (Δ199Hg = 0.13‰ ± 0.06‰, 2SD). No significant MIF was measured in any of the sea-floor rift samples from Guaymas Basin. In Ojo Caliente, Hg is both lost from the fluids and fractionated mass-dependently along a flow path from the hot spring vent to the outflow channel. We suggest that Hg loss and mass-dependent fractionation occur in this system due to volatilization of Hg0aq to Hg0g. In contrast, because all of the samples measured from Ojo Caliente exhibited approximately the same degree of MIF, it is not likely that measurable photochemical reduction of Hg is occurring in this system on the short timescale (i.e., minutes) of fluid discharge. Instead, we suggest that either (1) some portion of the Hg in the system was photochemically reduced at the earth's surface in the past and transported back to the subsurface (perhaps by groundwater

  13. Evaluation of Mercury Emissions from Coal-Fired Facilities with SCR and FGD Systems

    SciTech Connect

    J. A. Withum; J. E. Locke

    2006-02-01

    CONSOL Energy Inc., Research & Development (CONSOL), with support from the U.S. Department of Energy, National Energy Technology Laboratory (DOE) and the Electric Power Research Institute (EPRI), is evaluating the effects of selective catalytic reduction (SCR) on mercury (Hg) capture in coal-fired plants equipped with an electrostatic precipitator (ESP)--wet flue gas desulfurization (FGD) combination or a spray dyer absorber--fabric filter (SDA-FF) combination. In this program CONSOL is determining mercury speciation and removal at 10 coal-fired facilities. The principal purpose of this work is to develop a better understanding of the potential mercury removal ''co-benefits'' achieved by NO{sub x}, and SO{sub 2} control technologies. It is expected that this data will provide the basis for fundamental scientific insights into the nature of mercury chemistry in flue gas, the catalytic effect of SCR systems on mercury speciation and the efficacy of different FGD technologies for mercury capture. Ultimately, this insight could help to design and operate SCR and FGD systems to maximize mercury removal. The objectives are (1) to evaluate the effect of SCR on mercury capture in the ESP-FGD and SDA-FF combinations at coal-fired power plants, (2) evaluate the effect of SCR catalyst degradation on mercury capture; (3) evaluate the effect of low load operation on mercury capture in an SCR-FGD system, and (4) collect data that could provide the basis for fundamental scientific insights into the nature of mercury chemistry in flue gas, the catalytic effect of SCR systems on mercury speciation and the efficacy of different FGD technologies for mercury capture. This document, the tenth in a series of topical reports, describes the results and analysis of mercury sampling performed on two 468 MW units burning bituminous coal containing 1.3-1.7% sulfur. Unit 2 is equipped with an SCR, ESP, and wet FGD to control NO{sub x}, particulate, and SO{sub 2} emissions, respectively. Unit 1

  14. Development of mercury control technology for coal-fired systems

    SciTech Connect

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

    1995-08-01

    The emission of hazardous air pollutants (air toxics) from various industrial processes has emerged as a major environmental issue that was singled out for particular attention in the Clean Air Act Amendments of 1990. In particular, mercury emissions are the subject of several current EPA studies because of concerns over possible serious effects on human health. Some of those emissions originate in the combustion of coal, which contains trace amounts of mercury, and are likely to be the subject of control requirements in the relatively near future. Data collected by the Department of Energy (DOE) and the Electric Power Research Institute (EPRI) at operating electric-power plants have shown that conventional flue-gas cleanup (FGC) technologies are not very effective in controlling emissions of mercury in general, and are particularly poor at controlling emissions of elemental mercury. This paper gives an overview of research being conducted at Argonne National Laboratory on improving the capture of mercury in flue gas through the use of dry sorbents and/or wet scrubbers. The results and conclusions to date from the Argonne research on dry sorbents can be summarized as follows: lime hydrates, either regular or high-surface-area, are not effective in removing elemental mercury; mercury removals are enhanced by the addition of activated carbon; mercury removals with activated carbon decrease with increasing temperature, larger particle size, and decreasing mercury concentration in the gas; chemical pretreatment (e.g., with sulfur or CaCl{sub 2}) can greatly increase the removal capacity of activated carbon; chemically treated mineral substrates have the potential to be developed into effective and economical mercury sorbents; sorbents treated with different chemicals respond in significantly different ways to changes in flue-gas temperature.

  15. Mercury, cadmium and lead contamination in seafood: a comparative study to evaluate the usefulness of Target Hazard Quotients.

    PubMed

    Petroczi, A; Naughton, D P

    2009-02-01

    The aim of this paper is to explore the applicability of Target Hazard Quotient (THQ) estimations to inform on seafood hazards through metal contamination. The food recall data set was collated by the Laboratory of the Government Chemist (LGC, UK) over the period from January to November 2007. Pearson chi-square goodness of fit test, nonparametric correlation (Kendall tau) and Kruskal-Wallis test were used. Descriptive statistics and statistical analyses were computed by using Excel and SPSS 15.0. The vast majority of food alerts/recalls owing to metal contamination occur in seafood and during the summer months. Only swordfish and shark containing produce received over 10 recalls which were mainly for mercury contamination. Seafood produce originating from only 3 countries had over 10 recalls owing to metal contamination (Spain 50; France 11 and Indonesia 11). Based upon the food alert/recall system, the application of THQ estimations of risk in cases of metal contamination of seafood is questionable as THQ implies frequent if not daily exposure over a lifetime. Infrequent recalls owing to metal contamination and the absence of patterns make it highly unlikely that an individual would be subject to multiple exposures to significant levels of metal ions in seafood. PMID:19041361

  16. Overview of the SNS Target System Testing and Initial Beam Operation Experience

    SciTech Connect

    McManamy, Thomas J; Crabtree, J Allen; DeVore, Joe R; Jacobs, Lorelei L; Lousteau, David C; Rennich, Mark J

    2008-01-01

    The Spallation Neutron Source (SNS) construction project has been completed including initial beam operation with the mercury target, moderators and associated systems. The project was initiated in 1999, with groundbreaking in December of 1999. Final integrated system testing for the mercury target, cryogenic moderators, shutter systems, water and other utility systems and all control and safety systems were completed in April 2006 and first beam on target delivered April 28, 2006. This paper will give an overview of the system testing conducted in preparation for beam operation and initial operating experience with low power beams. One area of testing was extensive remote handling testing in the Target Service Bay to demonstrate all key operations associated with the target and mercury loop. Many improvements were implemented as a result of this experience. Another set of tests involved bringing the supercritical cryogenic moderator systems on line. Again, lesions learned here resulted in system changes. Testing of the four water loops was very time consuming because of the complexity of the systems and many instrumentation issues had to be resolved. A temporary phosphor view screen was installed on the front of the target which has been extremely useful in evaluating the beam profile on the target. Initial profile results will be presented. Target System performance for initial beam operation will be discussed. In general, all systems performed well with excellent availability. There were some unexpected findings. For example, xenon spallation gas products are believed to have deposited on a downstream gold amalgamation bed designed to remove mercury vapor and increased the local dose rate. A summary of findings and plans for ramping up in power will be given.

  17. Mercury Deposition Network Site Operator Training for the System Blank and Blind Audit Programs

    USGS Publications Warehouse

    Wetherbee, Gregory A.; Lehmann, Christopher M.B.

    2008-01-01

    The U.S. Geological Survey operates the external quality assurance project for the National Atmospheric Deposition Program/Mercury Deposition Network. The project includes the system blank and blind audit programs for assessment of total mercury concentration data quality for wet-deposition samples. This presentation was prepared to train new site operators and to refresh experienced site operators to successfully process and submit system blank and blind audit samples for chemical analysis. Analytical results are used to estimate chemical stability and contamination levels of National Atmospheric Deposition Program/Mercury Deposition Network samples and to evaluate laboratory variability and bias.

  18. Assessment of Measurement Uncertainties in a Commercial Atmospheric Mercury Speciation System

    NASA Astrophysics Data System (ADS)

    Luke, W. T.

    2015-12-01

    The Tekran® 2537/1130/1135 mercury speciation unit is a robust analytical system which is routinely deployed in regional, national, and global monitoring networks to measure concentrations of gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particulate-bound mercury (PBM). Standard operating protocols have been developed to ensure the collection of uniform and high-quality monitoring data. However, recent published laboratory and field research has pointed to the underestimation of GOM using KCl-coated denuders in humid and/or ozone-rich environments. Under very dry conditions, contamination of the Tekran® regenerable particle filter used to collect PBM can lead to the conversion of GEM to PBM, and a subsequent overestimation of reactive mercury (RM) concentrations. In March 2015 we deployed a total mercury (TM)/GEM detector at NOAA's Mauna Loa Observatory (MLO: Elevation 3397 m) on the island of Hawaii, to calculate reactive mercury (RM = GOM + PBM) as the difference of TM - GEM. We also installed a second Tekran® speciation system to accompany an identical system operating at MLO since 2011. We will present side-by-side comparisons of ambient data collected by the three instruments under a variety of conditions, as well as measured performance parameters assessed using a GOM calibration device. Initial results confirm the degradation of GOM measurement under even moderate levels of humidity, but also suggest that current AMNet sampling and data reduction protocols can exacerbate the problem.

  19. Development of mercury control enhancements for flue-gas cleanup systems

    SciTech Connect

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

    1995-08-01

    Combustion sources, including those using coal for fuel, contribute a significant fraction of total anthropogenic mercury emissions. Unfortunately, recent field studies have shown that current flue-gas cleanup (FGC) systems are relatively ineffective in controlling elemental mercury, which is a major component of the mercury emissions for many systems. Research at Argonne National Laboratory has been focused on techniques to enhance the capture of elemental mercury in existing FGC systems. For dry processes, these studies have included evaluation of the factors that control mercury capture by commercial activated carbons (both with and without chemical pretreatment), testing of novel proprietary sorbents under development by several firms, and investigation of sorbents based upon chemical pretreatment of low-cost mineral substrates. To enhance the ability of wet scrubbers to capture mercury, the studies have looked at the effects of improved mass transfer through both mechanical and chemical means, as well as the conversion of elemental mercury into more soluble species that can be easily absorbed.

  20. Data quality through a web-based QA/QC system: implementation for atmospheric mercury data from the global mercury observation system.

    PubMed

    D'Amore, Francesco; Bencardino, Mariantonia; Cinnirella, Sergio; Sprovieri, Francesca; Pirrone, Nicola

    2015-08-01

    The overall goal of the on-going Global Mercury Observation System (GMOS) project is to develop a coordinated global monitoring network for mercury, including ground-based, high altitude and sea level stations. In order to ensure data reliability and comparability, a significant effort has been made to implement a centralized system, which is designed to quality assure and quality control atmospheric mercury datasets. This system, GMOS-Data Quality Management (G-DQM), uses a web-based approach with real-time adaptive monitoring procedures aimed at preventing the production of poor-quality data. G-DQM is plugged on a cyberinfrastructure and deployed as a service. Atmospheric mercury datasets, produced during the first-three years of the GMOS project, are used as the input to demonstrate the application of the G-DQM and how it identifies a number of key issues concerning data quality. The major issues influencing data quality are presented and discussed for the GMOS stations under study. Atmospheric mercury data collected at the Longobucco (Italy) station is used as a detailed case study. PMID:26174740

  1. Infrared Targeting System (IRTS) demonstration

    NASA Astrophysics Data System (ADS)

    Ohair, Mark A.; Eucker, Shelly S.; Eucker, Brad A.; Lewis, Tim

    1992-02-01

    The objective of the Infrared Targeting System (IRTS) is to successfully demonstrate the mission performance that can be achieved in manned air-to-ground targeting applications utilizing a synergistic combination of state of the art active/passive infrared sensor and automatic target recognizer (ATR) technologies. The IRTS program is centered around a demonstration FLIR/Laser Radar/ATR (FLASHER). The FLASHER consists of a dual field of view (2 x 2 degree and 6 x 6 degree) second generation FLIR pixel mapped to a CO2 laser radar, with a FLIR ATR processor, a laser radar ATR processor, and a sensor fusion ATR processor. Following construction and laboratory testing of the IRTS, the system will be installed on a test aircraft and demonstrated in flight against realistic tactical, strategic, and special operations scenarios.

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

    DOEpatents

    Grossman, Mark W.

    1987-01-01

    An apparatus and method for monitoring the flow of mercury in a system. 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.

  3. INTERACTION BETWEEN METHYL MERCURY AND RADIATION EFFECTS ON NERVOUS SYSTEMS

    EPA Science Inventory

    The interaction between methyl mercury and ionizing radiation was investigated in a series of experiments using rats, hamsters, and squirrel monkeys to study the effects produced and possible mechanisms of action. Parameters evaluated included several measurements of behavior, br...

  4. Hypersonic MHD Propulsion System Integration for the Mercury Lightcraft

    SciTech Connect

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

    2004-03-30

    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.

  5. Hypersonic MHD Propulsion System Integration for the Mercury Lightcraft

    NASA Astrophysics Data System (ADS)

    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.

  6. Functional and molecular effects of mercury compounds on the human OCTN1 cation transporter: C50 and C136 are the targets for potent inhibition.

    PubMed

    Galluccio, Michele; Pochini, Lorena; Peta, Valentina; Iannì, Maria; Scalise, Mariafrancesca; Indiveri, Cesare

    2015-03-01

    The effect of mercury compounds has been tested on the organic cation transporter, hOCTN1. MeHg(+), Hg(2+), or Cd(2+) caused strong inhibition of transport. 1,4-Dithioerythritol (DTE), cysteine (Cys), and N-acetyl-l-cysteine reversed (NAC) the inhibition at different extents. 2-Aminoethyl methanethiosulfonate hydrobromide (MTSEA), a prototype SH reagent, exerted inhibition of transport similar to that observed for the mercurial agents. To investigate the mechanism of action of mercurials, mutants of hOCTN1 in which each of the Cys residues was substituted by Ala have been constructed, over-expressed in Escherichia coli, and purified. Tetraethylammonium chloride (TEA) uptake mediated by each mutant in proteoliposomes was comparable to that of wild type (WT). IC50 values of the WT and mutants for the mercury compounds were derived from dose-response analyses. The mutants C50A and C136A showed significant increase of IC50 indicating that the 2 Cys residues were involved in the interaction with the mercury compounds and inhibition of the transporter. The double mutant C50A/C136A was constructed; the lack of inhibition confirmed that the 2 Cys residues are the targets of mercury compounds. MTSEA showed similar behavior with respect to the mercurial reagents with the difference that increased IC50 was observed also in the C81A mutant. Similar results were obtained when transport was measured as acetylcholine uptake. Ethyl mercury (Thimerosal) inhibited hOCTN1 as well. C50A, C50A/C136A and, at very lower extent, C136A showed increased IC50 indicating that C50 was the major target of this mercury compound. The homology model of hOCTN1 was built using as template PiPT and validated by the experimental data on mutant proteins. PMID:25490951

  7. Design, Operations, and Safety Report for the MERIT Target System

    SciTech Connect

    Graves, Van B; Spampinato, Philip Thomas

    2007-09-01

    The Mercury Intense Target Project (MERIT) is a proof-of-principal experiment to determine the feasibility of using a free-jet of Hg as a spallation target in a Neutrino Factory or a Muon Collider facility. The 1-cm-diameter, 20-m/sec jet will be generated inside a 15-Tesla magnetic field, and high-speed optical diagnostics will be used to photograph the interaction between the Hg jet and a 24-GeV proton beam.The experiment is scheduled to be conducted at CERN in 2007. ORNL is responsible for the design, fabrication, and testing of a system to deliver the Hg jet within the confines of the 15-cm magnet bore. This report documents the functional and safety requirements of the Hg system along with descriptions of its interfaces to the other experimental equipment.

  8. Split-target neutronics and the MLNSC spallation target system

    SciTech Connect

    Russell, G.J.; Ferguson, P.D.; Pitcher, E.J.; Court, J.D.

    1996-12-31

    The Manuel Lujan, Jr., Neutron Scattering Center (MLNSC) at the Los Alamos National Laboratory is one of four operating Short-Pulse Spallation Sources worldwide. The MLNSC target system (composed of targets, moderators, and reflectors) was first installed in 1985. The target system employs a split tungsten spallation target with a void space in between (the flux-trap gap); this target system will be upgraded in 1998. The ability to efficiently split a spallation target allowed us to introduce the concept of flux-trap moderators and ultimately the notion of backscattering and upstream moderators. The upgraded MLNSC target system will employ both flux-trap and upstream/backscattering moderators to simultaneously service 16 neutron flight paths with high-intensity neutron beams for materials science research.

  9. Spatially Oscillating Activity and Microbial Succession of Mercury-Reducing Biofilms in a Technical-Scale Bioremediation System

    PubMed Central

    von Canstein, Harald; Li, Ying; Leonhäuser, Johannes; Haase, Elke; Felske, Andreas; Deckwer, Wolf-Dieter; Wagner-Döbler, Irene

    2002-01-01

    Mercury-contaminated chemical wastewater of a mercury cell chloralkali plant was cleaned on site by a technical-scale bioremediation system. Microbial mercury reduction of soluble Hg(II) to precipitating Hg(0) decreased the mercury load of the wastewater during its flow through the bioremediation system by up to 99%. The system consisted of a packed-bed bioreactor, where most of the wastewater's mercury load was retained, and an activated carbon filter, where residual mercury was removed from the bioreactor effluent by both physical adsorption and biological reduction. In response to the oscillation of the mercury concentration in the bioreactor inflow, the zone of maximum mercury reduction oscillated regularly between the lower and the upper bioreactor horizons or the carbon filter. At low mercury concentrations, maximum mercury reduction occurred near the inflow at the bottom of the bioreactor. At high concentrations, the zone of maximum activity moved to the upper horizons. The composition of the bioreactor and carbon filter biofilms was investigated by 16S-23S ribosomal DNA intergenic spacer polymorphism analysis. Analysis of spatial biofilm variation showed an increasing microbial diversity along a gradient of decreasing mercury concentrations. Temporal analysis of the bioreactor community revealed a stable abundance of two prevalent strains and a succession of several invading mercury-resistant strains which was driven by the selection pressure of high mercury concentrations. In the activated carbon filter, a lower selection pressure permitted a steady increase in diversity during 240 days of operation and the establishment of one mercury-sensitive invader. PMID:11916716

  10. FULL-SCALE TESTING OF ENHANCED MERCURY CONTROL TECHNOLOGIES FOR WET FGD SYSTEMS

    SciTech Connect

    D.K. McDonald; G.T. Amrhein; G.A. Kudlac; D. Madden Yurchison

    2003-05-07

    Wet flue gas desulfurization (wet FGD) systems are currently installed on about 25% of the coal-fired utility generating capacity in the U.S., representing about 15% of the number of coal-fired units. Depending on the effect of operating parameters such as mercury content of the coal, form of mercury (elemental or oxidized) in the flue gas, scrubber spray tower configuration, liquid-to-gas ratio, and slurry chemistry, FGD systems can provide cost-effective, near-term mercury emissions control options with a proven history of commercial operation. For boilers already equipped with FGD systems, the incremental cost of any vapor phase mercury removal achieved is minimal. To be widely accepted and implemented, technical approaches that improve mercury removal performance for wet FGD systems should also have low incremental costs and have little or no impact on operation and SO{sub 2} removal performance. The ultimate goal of the Full-scale Testing of Enhanced Mercury Control for Wet FGD Systems Program was to commercialize methods for the control of mercury in coal-fired electric utility systems equipped with wet flue gas desulfurization (wet FGD). The program was funded by the U.S. Department of Energy's National Energy Technology Laboratory, the Ohio Coal Development Office within the Ohio Department of Development, and Babcock & Wilcox. Host sites and associated support were provided by Michigan South Central Power Agency (MSCPA) and Cinergy. Field-testing was completed at two commercial coal-fired utilities with wet FGD systems: (1) MSCPA's 55 MW{sub e} Endicott Station and (2) Cinergy's 1300 MW{sub e} Zimmer Station. Testing was conducted at these two locations because of the large differences in size and wet scrubber chemistry. Endicott employs a limestone, forced oxidation (LSFO) wet FGD system, whereas Zimmer uses Thiosorbic{reg_sign} Lime (magnesium enhanced lime) and ex situ oxidation. Both locations burn Ohio bituminous coal.

  11. Assessing the Fidelity of Atmospheric Mercury Measurements Using a Commercial Speciation System

    NASA Astrophysics Data System (ADS)

    Luke, W. T.; Ren, X.; Kelley, P.; Olson, M.

    2014-12-01

    The Tekran mercury speciation system is the only commercially viable instrumentation for the routine measurement of mercury compounds in the atmosphere, and is widely deployed in mercury monitoring networks worldwide. To date, however, many key performance measures of the instrumentation have yet to be adequately addressed or documented. While a number of controlled experiments have been conducted in laboratory settings, issues of potential measurement artifacts, non-quantitative collection efficiencies of GOM species, humidity effects, etc. remain to be explored under field conditions. This presentation will address some issues surrounding the accuracy, reproducibility, and robustness of speciated mercury measurements made with the Tekran analytical instrumentation deployed at three AMNet sites operated by NOAA's Air Resources Laboratory: a coastal location (Grand Bay NERR, MS); an inland site in the Mid-Atlantic region (Beltsville, MD); and a high elevation site in the remote free troposphere (Mauna Loa Observatory, HI).

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

    SciTech Connect

    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

  13. EVALUATION OF MERCURY EMISSIONS FROM COAL-FIRED FACILITIES WITH SCR AND FGD SYSTEMS

    SciTech Connect

    J.A. Withum

    2006-03-07

    CONSOL Energy Inc., Research & Development (CONSOL), with support from the U.S. Department of Energy, National Energy Technology Laboratory (DOE) and the Electric Power Research Institute (EPRI), evaluated the effects of selective catalytic reduction (SCR) on mercury (Hg) capture in coal-fired plants equipped with an electrostatic precipitator (ESP)-wet flue gas desulfurization (FGD) combination or a spray dyer absorber-fabric filter (SDA-FF) combination. In this program CONSOL determined mercury speciation and removal at 10 bituminous coal-fired facilities; at four of these facilities, additional tests were performed on units without SCR, or with the existing SCR bypassed. This project final report summarizes the results and discusses the findings of the body of work as a whole. Eleven Topical Reports were issued (prior to this report) that describe in great detail the sampling results at each of the ten power plants individually. The results showed that the SCR-FGD combination removed a substantial fraction of mercury from flue gas. The coal-to-stack mercury removals ranged from 65% to 97% for the units with SCR and from 53% to 87% for the units without SCR. There was no indication that any type of FGD system was more effective at mercury removal than others. The coal-to-stack mercury removal and the removal in the wet scrubber were both negatively correlated with the elemental mercury content of the flue gas and positively correlated with the scrubber liquid chloride concentration. The coal chlorine content was not a statistically significant factor in either case. Mercury removal in the ESP was positively correlated with the fly ash carbon content and negatively correlated with the flue gas temperature. At most of the units, a substantial fraction (>35%) of the flue gas mercury was in the elemental form at the boiler economizer outlet. After passing through the SCR-air heater combination very little of the total mercury (<10%) remained in the elemental form in

  14. EVALUATION OF MERCURY EMISSIONS FROM COAL-FIRED FACILITIES WITH SCR AND FGD SYSTEMS

    SciTech Connect

    J. A. Withum; S.C. Tseng; J. E. Locke

    2004-10-31

    CONSOL Energy Inc., Research & Development (CONSOL), with support from the U.S. Department of Energy, National Energy Technology Laboratory (DOE) is evaluating the effects of selective catalytic reduction (SCR) on mercury (Hg) capture in coal-fired plants equipped with an electrostatic precipitator (ESP) - wet flue gas desulfurization (FGD) combination or a spray dyer absorber--fabric filter (SDA-FF) combination. In this program CONSOL is determining mercury speciation and removal at 10 coal-fired facilities. The objectives are (1) to evaluate the effect of SCR on mercury capture in the ESP-FGD and SDA-FF combinations at coal-fired power plants, (2) evaluate the effect of catalyst degradation on mercury capture; (3) evaluate the effect of low load operation on mercury capture in an SCR-FGD system, and (4) collect data that could provide the basis for fundamental scientific insights into the nature of mercury chemistry in flue gas, the catalytic effect of SCR systems on Hg speciation and the efficacy of different FGD technologies for Hg capture. This document, the second in a series of topical reports, describes the results and analysis of mercury sampling performed on a 330 MW unit burning a bituminous coal containing 1.0% sulfur. The unit is equipped with a SCR system for NOx control and a spray dryer absorber for SO{sub 2} control followed by a baghouse unit for particulate emissions control. Four sampling tests were performed in March 2003. Flue gas mercury speciation and concentrations were determined at the SCR inlet, air heater outlet (ESP inlet), and at the stack (FGD outlet) using the Ontario Hydro method. Process stream samples for a mercury balance were collected to coincide with the flue gas measurements. Due to mechanical problems with the boiler feed water pumps, the actual gross output was between 195 and 221 MW during the tests. The results showed that the SCR/air heater combination oxidized nearly 95% of the elemental mercury. Mercury removal, on a

  15. FY09 assessment of mercury reduction at SNL/NM.

    SciTech Connect

    McCord, Samuel Adam

    2010-02-01

    This assessment takes the result of the FY08 performance target baseline of mercury at Sandia National Laboratories/New Mexico, and records the steps taken in FY09 to collect additional data, encourage the voluntary reduction of mercury, and measure success. Elemental (metallic) mercury and all of its compounds are toxic, and exposure to excessive levels can permanently damage or fatally injure the brain and kidneys. Elemental mercury can also be absorbed through the skin and cause allergic reactions. Ingestion of inorganic mercury compounds can cause severe renal and gastrointestinal damage. Organic compounds of mercury such as methyl mercury, created when elemental mercury enters the environment, are considered the most toxic forms of the element. Exposures to very small amounts of these compounds can result in devastating neurological damage and death.1 SNL/NM is required to report annually on the site wide inventory of mercury for the Environmental Protection Agency's (EPA) Toxics Release Inventory (TRI) Program, as the site's inventory is excess of the ten pound reportable threshold quantity. In the fiscal year 2008 (FY08) Pollution Prevention Program Plan, Section 5.3 Reduction of Environmental Releases, a performance target stated was to establish a baseline of mercury, its principle uses, and annual quantity or inventory. This was accomplished on July 29, 2008 by recording the current status of mercury in the Chemical Information System (CIS).

  16. 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.

    PubMed

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

    2013-02-01

    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. PMID:23305917

  17. Federal Data Repository Research: Recent Developments in Mercury Search System Architecture

    NASA Astrophysics Data System (ADS)

    Devarakonda, R.

    2015-12-01

    New data intensive project initiatives needs new generation data system architecture. This presentation will discuss the recent developments in Mercury System [1] including adoption, challenges, and future efforts to handle such data intensive projects. Mercury is a combination of three main tools (i) Data/Metadata registration Tool (Online Metadata Editor): The new Online Metadata Editor (OME) is a web-based tool to help document the scientific data in a well-structured, popular scientific metadata formats. (ii) Search and Visualization Tool: Provides a single portal to information contained in disparate data management systems. It facilitates distributed metadata management, data discovery, and various visuzalization capabilities. (iii) Data Citation Tool: In collaboration with Department of Energy's Oak Ridge National Laboratory (ORNL) Mercury Consortium (funded by NASA, USGS and DOE), established a Digital Object Identifier (DOI) service. Mercury is a open source system, developed and managed at Oak Ridge National Laboratory and is currently being funded by three federal agencies, including NASA, USGS and DOE. It provides access to millions of bio-geo-chemical and ecological data; 30,000 scientists use it each month. Some recent data intensive projects that are using Mercury tool: USGS Science Data Catalog (http://data.usgs.gov/), Next-Generation Ecosystem Experiments (http://ngee-arctic.ornl.gov/), Carbon Dioxide Information Analysis Center (http://cdiac.ornl.gov/), Oak Ridge National Laboratory - Distributed Active Archive Center (http://daac.ornl.gov), SoilSCAPE (http://mercury.ornl.gov/soilscape). References: [1] Devarakonda, Ranjeet, et al. "Mercury: reusable metadata management, data discovery and access system." Earth Science Informatics 3.1-2 (2010): 87-94.

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

    PubMed

    Lithwick, Yoram; Wu, Yanqin

    2014-09-01

    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. PMID:24367108

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

    PubMed Central

    Lithwick, Yoram; Wu, Yanqin

    2014-01-01

    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. PMID:24367108

  20. System Safety in Early Manned Space Program: A Case Study of NASA and Project Mercury

    NASA Technical Reports Server (NTRS)

    Hansen, Frederick D.; Pitts, Donald

    2005-01-01

    This case study provides a review of National Aeronautics and Space Administration s (NASA's) involvement in system safety during research and evolution from air breathing to exo-atmospheric capable flight systems culminating in the successful Project Mercury. Although NASA has been philosophically committed to the principals of system safety, this case study points out that budget and manpower constraints-as well as a variety of internal and external pressures can jeopardize even a well-designed system safety program. This study begins with a review of the evolution and early years of NASA's rise as a project lead agency and ends with the lessons learned from Project Mercury.

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

    DOEpatents

    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.

  2. A rotating target wheel system for Gammasphere

    SciTech Connect

    Greene, John P.; Falout, Joseph W.; Lister, Christopher J.; Nardi, Bruce G.; Fox, John D.

    1999-06-10

    A description is given for a low-mass, rotating target wheel to be used within the Gammasphere target chamber. This system was developed for experiments employing high beam currents in order to extend lifetimes of targets using low-melting point target material. The design is based on a previously successful implementation of rotating target wheels for the Argonne Positron Experiment (APEX) as well as the Fragment Mass Analyser (FMA) at ATLAS (Argonne Tandem Linac Accelerator System). A brief history of these rotating target wheel systems is given as well as a discussion on target preparation and performance.

  3. Extensive study of shape and surface structure formation in the mercury beating heart system.

    PubMed

    Ramírez-Álvarez, E; Ocampo-Espindola, J L; Montoya, Fernando; Yousif, F; Vázquez, F; Rivera, M

    2014-11-13

    A phenomenological study of the mercury beating heart system in a three electrode electrochemical cell configuration forced with a harmonic perturbation is presented. The system is controlled via a potentiostat, where the mercury drop is electrically connected to a platinum wire and acts as the working electrode. This configuration exhibits geometrical shapes and complex surface structures when a harmonic signal is superimposed to the working electrode potential. This study involves a wide range of frequencies and amplitudes of the forcing signal. Differents levels of structure complexity are observed as a function of the parameters of the applied perturbation. At certain amplitudes and frequencies, rotational behavior is also observed. PMID:25343208

  4. DEVELOPMENT OF ANALYTICAL METHODS FOR THE QUANTIFICATION OF THE CHEMICAL FORMS OF MERCURY AND OTHER TARGET POLLUTANTS IN COAL-FIRED BOILER FLUE GAS

    SciTech Connect

    Terence J. McManus, Ph.D.

    1999-06-30

    Since approximately 55% of the electrical power produced in the U. S. is generated by coal-based power utility plants, there is serious concern about the massive amounts of coal combustion products emitted into the atmosphere annually. Furthermore, Title III of the 1990 Clean Air Act Amendments (CAAA) requires the measurement and inventory of a possible 189 hazardous air pollutants (HAPs) from any stationary source producing more than 10 tons per year of any one pollutant or more than 25 tons per year of total pollutants. Although power utilities are not presently included on the list of source categories, the CAAA requires the U. S. Environmental Protection Agency to carry out a study of emissions from electricity generation using fossil fuels. Since many of these HAPs are known to be present in coal derived flue gas, coal-fired electric power utilities may be subject to regulation following these studies if Congress considers it necessary. In a cooperative effort with the U. S. Environmental Protection Agency (EPA), the U. S. Department of Energy (DOE) through its Federal Energy Technology Center (FETC) initiated such a study in 1991. DOE-FETC commissioned five primary contractors to conduct emission studies at eight different coal-fired electric utilities. The eight sites represented a cross section of feed coal type, boiler designs, and particulate and gaseous pollutant control technologies. The major goal of these studies was to determine the sampling and analytical methodologies that could be used efficiently to perform these emission tests while producing representative and reliable emission data. The successful methodology could then be recommended to the EPA for use in compliance testing in the event the regulation of air toxic emissions from coal-fired power plants is implemented. A secondary purpose of the testing was to determine the effectiveness of the control technologies in reducing target hazardous air pollutants. Advanced Technology Systems, Inc

  5. Cooling System for the Merit High-Power Target Experiment

    NASA Astrophysics Data System (ADS)

    Haug, F.; Pereira, H.; Silva, P.; Pezzetti, M.; Pavlov, O.; Pirotte, O.; Metselaar, J.; Efthymiopoulos, I.; Fabich, A.; Lettry, J.; Kirk, H. G.; McDonald, K. T.; Titus, P.; Bennett, J. R. J.

    2010-04-01

    MERIT is a proof-of-principle experiment of a target station suitable as source for future muon colliders or neutrino factories. When installed at the CERN (European Organization for Nuclear Research) PS (Proton Synchrotron) complex fast-extracted high-intensity proton beams intercepted a free mercury jet inside a normal-conducting, pulsed 15-T capture solenoid magnet cooled with liquid nitrogen. Up to 25 MJ of Joule heat was dissipated in the magnet during a pulse. The fully automated, remotely controlled cryogenic system of novel design permitted the transfer of nitrogen by the sole means of differential pressures inside the vessels. This fast cycling system permitted several hundred tests in less than three weeks during the 2007 data taking campaign.

  6. Mercury's Messenger

    ERIC Educational Resources Information Center

    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.…

  7. RECOVERY OF MERCURY FROM CONTAMINATED LIQUID WASTES

    SciTech Connect

    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

  8. Advances in understanding the renal transport and toxicity of mercury

    SciTech Connect

    Zalups, R.K. ); Lash, L.H. )

    1994-01-01

    As a result of industrialization and changes in the environment during the twentieth century, humans and animals are exposed to numerous chemical forms of mercury, including elemental mercury vapor (Hg[sup 0]), inorganic mercurous (Hg[sup +]) and mercuric (Hg[sup 2+]) compounds, and organic mercuric (R-Hg[sup +] or R-Hg-R; where R represents any organic ligand) compounds. The risk of exposure and subsequent intoxication is of increasing concern because of the steadily increasing deposition of mercury in the environment (Fitzgerald Clarkson, 1991). All forms of mercury have nephrotoxic effects, although disposition and toxicity of mercury in tissues can vary depending on the chemical form of mercury. For example, the initial toxic effects of both elemental mercury and organic forms of mercury are observed in the nervous system. This is due to their lipophilicity, which allows them to cross the blood-brain barrier. At later times, hepatotoxicity and nephrotoxicity can develop. With inorganic mercurous or mercuric salts, the most prominent effect is nephrotoxicity. Until recently, little was known about the mechanisms involved in the nephropathy induced by mercury. The purpose of this article is to review recent data on the intrarenal accumulation and disposition, nephrotoxicity, and target site specificity of mercury, and factors that modify or alter renal injury induced by mercury. 170 refs., 7 figs.

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

    SciTech Connect

    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.

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

    SciTech Connect

    Gary M. Blythe

    2002-07-17

    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 April 1, 2002 through June 30, 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 in a stable form 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 will test previously identified, effective catalyst materials at a larger, pilot scale and in a commercial form, so as to provide engineering data for future full-scale 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 third full reporting period for the subject Cooperative Agreement. During this period, most of the project efforts were related to constructing the pilot unit and conducting laboratory runs to help size catalysts for the pilot unit. This technical progress report provides an update on these two efforts.

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

    SciTech Connect

    Gary M. Blythe

    2003-07-01

    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 April 1, 2003 through June 30, 2003. 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 cofunders. URS Group is the prime contractor. The mercury control 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 current project is testing previously identified, effective catalyst materials at a larger, pilot scale and in a commercial form, to provide engineering data for future full-scale designs. The pilot-scale tests will continue for approximately 14 months at each of two sites to provide longer-term catalyst life data. This is the seventh full reporting period for the subject Cooperative Agreement. During this period, project efforts included continued operation of the first pilot unit, conducting catalyst activity measurements, installing sonic horns for on-line catalyst cleaning, and installing the fourth catalyst, all for the GRE Coal Creek site. CPS began installation of the second mercury oxidation catalyst pilot unit at their Spruce Plant during the quarter. Laboratory efforts were conducted to support catalyst selection for that second pilot unit. This technical progress report provides an update on these efforts.

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

    SciTech Connect

    Gary M. Blythe

    2002-10-04

    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 July 1, 2002 through September 30, 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 in a stable form with the byproducts from the FGD system. The coprecipitated mercury does not appear to adversely affect the disposal or reuse properties of the FGD byproduct. The current project will test previously identified, effective catalyst materials at a larger, pilot scale and in a commercial form, so as to provide engineering data for future full-scale 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 fourth full reporting period for the subject Cooperative Agreement. During this period, most of the project efforts were related to completing, installing and starting up the pilot unit, completing laboratory runs to size catalysts, and procuring catalysts for the pilot unit. This technical progress report provides an update on these efforts.

  13. Multiple target laser ablation system

    DOEpatents

    Mashburn, Douglas N.

    1996-01-01

    A laser ablation apparatus and method are provided in which multiple targets consisting of material to be ablated are mounted on a movable support. The material transfer rate is determined for each target material, and these rates are stored in a controller. A position detector determines which target material is in a position to be ablated, and then the controller controls the beam trigger timing and energy level to achieve a desired proportion of each constituent material in the resulting film.

  14. Multiple target laser ablation system

    DOEpatents

    Mashburn, D.N.

    1996-01-09

    A laser ablation apparatus and method are provided in which multiple targets consisting of material to be ablated are mounted on a movable support. The material transfer rate is determined for each target material, and these rates are stored in a controller. A position detector determines which target material is in a position to be ablated, and then the controller controls the beam trigger timing and energy level to achieve a desired proportion of each constituent material in the resulting film. 3 figs.

  15. Evaluation of microwave digestion systems for mercury recovery in an oil matrix

    SciTech Connect

    Whitaker, M.J.; Clymire, J.W.

    1997-09-01

    The scope of this document is to characterize three microwave systems developed by CEM Corporation. The purpose of this investigative work was to evaluate the performance of each system for dissolution qualities and the recovery of mercury in an oil based matrix. The microwave systems evaluated were the heavy duty vessel system (HDV), the advanced composite system (ACV), and the open vessel system (OVS). All three systems have automated features, but all systems are limited by one factor or another. EPA method 3051 was the procedure used for sample preparation for this project. This particular microwave digestion method can also be used for other metal analytes of interest. Of the three different systems, only the HDV (now UDV) demonstrated complete digestion of the oil based matrix in a one step process and acceptable mercury recoveries.

  16. Materials technology programs in support of a mercury Rankine space power system

    NASA Technical Reports Server (NTRS)

    Stone, P. L.

    1973-01-01

    A large portion of the materials technology is summarized that was generated in support of the development of a mercury-rankine space power system (SNAP-8). The primary areas of investigation are: (1) the compatibility of various construction materials with the liquid metals mercury and NaK, (2) the mechanical properties of unalloyed tantalum, and (3) the development of refractory metal/austenitic stainless steel tubing and transition joints. The primary results, conclusions, and state of technology at the completion of this effort for each of these areas are summarized. Results of possible significance to other applications are highlighted.

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

    SciTech Connect

    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 demonstration early, during

  18. Got Mercury?

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    Many lamps used in various spacecraft contain elemental mercury, which is efficiently absorbed through the lungs as a vapor. The liquid metal vaporizes slowly at room temperature, but may be completely vaporized when lamps are operating. Because current spacecraft environmental control systems are unable to remove mercury vapors, we considered short-term and long-term exposures. Using an existing study, we estimated mercury vapor releases from lamps that are not in operation during missions lasting less than or equal to 30 days; whereas we conservatively assumed complete vaporization from lamps that are operating or being used during missions lasing more than 30 days. Based on mercury toxicity, the Johnson Space Center's Toxicology Group recommends stringent safety controls and verifications for any hardware containing elemental mercury that could yield airborne mercury vapor concentrations greater than 0.1 mg/m3 in the total spacecraft atmosphere for exposures lasting less than or equal to 30 days, or concentrations greater than 0.01 mg/m3 for exposures lasting more than 30 days.

  19. Targeting geothermal exploration sites in the Mount St. Helens area using soil mercury surveys

    SciTech Connect

    Holmes, J.; Waugh, K.

    1983-11-01

    The background mercury level was determined for the areas studied, providing preliminary information for future work. Identification of areas which might merit more intensive sampling was also accomplished. The clusters of samples with high Hg concentrations in both areas may indicate high heat flow and should be investigated further. Problems involving the use of this method in the Cascades were also identified. Both areas north and south of the mountain had approximately the same standard deviation (expressed as a percentage of the mean), even though the sampling horizons seemed much more consistent and less disturbed in the Marble Mountain area than in the Green River Soda Springs area. This may indicate that for these areas, secondary controls are more important, or that Hg anomalies are much smaller than indicated in studies of other areas.

  20. Mercury and mercury compounds toxicology. (Latest citations from the Life Sciences Collection data base). Published Search

    SciTech Connect

    Not Available

    1992-10-01

    The bibliography contains citations concerning the toxic effects of mercury and mercury compounds on biological systems. Mercury metal, mercury vapors, organic mercury compounds, mercury halides, and other inorganic mercury compounds are discussed. Citations include acute, chronic, environmental, metabolic, and pathological effects; and clinical biochemistry of mercury exposure. Heavy metal pollution and bioaccumulation are referenced in related bibliographies. (Contains 250 citations and includes a subject term index and title list.)

  1. Mercury and mercury compounds toxicology. (Latest citations from the Life Sciences Collection database). Published Search

    SciTech Connect

    Not Available

    1994-04-01

    The bibliography contains citations concerning the toxic effects of mercury and mercury compounds on biological systems. Mercury metal, mercury vapors, organic mercury compounds, mercury halides, and other inorganic mercury compounds are discussed. Citations include acute, chronic, environmental, metabolic, and pathological effects; and clinical biochemistry of mercury exposure. Heavy metal pollution and bioaccumulation are referenced in related bibliographies. (Contains 250 citations and includes a subject term index and title list.)

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

    SciTech Connect

    Gary M. Blythe

    2006-03-31

    This document summarizes progress on Cooperative Agreement DE-FC26-04NT41992, ''Pilot Testing of Mercury Oxidation Catalysts for Upstream of Wet FGD Systems'', during the time-period January 1 through March 31, 2006. 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 flue gas from coal combustion, and the use of a wet flue gas desulfurization (FGD) system downstream to remove the oxidized mercury at high efficiency. The project is being co-funded by the U.S. DOE National Energy Technology Laboratory, EPRI, Great River Energy (GRE), TXU Generation Company LP, the Southern Company, and Duke Energy. URS Group is the prime contractor. The mercury control process under development uses honeycomb catalysts to promote the oxidation of elemental mercury in the flue gas from coal-fired power plants that have wet lime or limestone FGD systems. Oxidized mercury is removed in the wet FGD absorbers and leaves with the byproducts from the FGD system. The current project is testing previously identified catalyst materials at pilot scale and in a commercial form to provide engineering data for future full-scale designs. The pilot-scale tests will continue for approximately 14 months or longer at each of two sites to provide longer-term catalyst life data. Pilot-scale wet FGD tests are being conducted periodically at each site to confirm the ability to scrub the catalytically oxidized mercury at high efficiency. This is the ninth reporting period for the subject Cooperative Agreement. During this period, project efforts primarily consisted of operating the catalyst pilot units at the TXU Generation Company LP's Monticello Steam Electric Station and at Georgia Power's Plant Yates. Two catalyst activity measurement trips were made to Plant Yates during the quarter. This Technical Progress Report presents catalyst activity results from the oxidation catalyst pilot unit at Plant Yates and

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

    SciTech Connect

    Gary M. Blythe

    2003-05-01

    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 January 1, 2003 through March 31, 2003. 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 cofunders. URS Group is the prime contractor. The mercury control 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 current project is testing previously identified, effective catalyst materials at a larger, pilot scale and in a commercial form, to provide engineering data for future full-scale 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 sixth full reporting period for the subject Cooperative Agreement. During this period, project efforts included continued operation of the pilot unit with three catalysts, conducting catalyst activity measurements, and procuring the fourth catalyst, all for the GRE Coal Creek pilot unit site. Laboratory efforts were also conducted to support catalyst selection for the second pilot unit site, at CPS' Spruce Plant. This technical progress report provides an update on these efforts.

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

    SciTech Connect

    Gary M. Blythe

    2003-10-01

    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 July 1, 2003 through September 30, 2003. 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 cofunders. URS Group is the prime contractor. The mercury control 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 current project is testing previously identified, effective catalyst materials at a larger, pilot scale and in a commercial form, to provide engineering data for future full-scale designs. The pilot-scale tests will continue for approximately 14 months at each of two sites to provide longer-term catalyst life data. This is the eighth full reporting period for the subject Cooperative Agreement. During this period, project efforts included continued operation of the first pilot unit at the GRE Coal Creek site with all four catalysts in service and sonic horns installed for on-line catalyst cleaning. During the quarter, a catalyst activity measurement trip and mercury SCEM relative accuracy tests were completed, and catalyst pressure drop was closely monitored with the sonic horns in operation. CPS completed the installation of the second mercury oxidation catalyst pilot unit at their Spruce Plant during the quarter, and the four

  5. Impact of Oxy-Fuel Conditions on Elemental Mercury Re-Emission in Wet Flue Gas Desulfurization Systems.

    PubMed

    Fernández-Miranda, Nuria; Lopez-Anton, M Antonia; Torre-Santos, Teresa; Díaz-Somoano, Mercedes; Martínez-Tarazona, M Rosa

    2016-07-01

    This study evaluates some of the variables that may influence mercury retention in wet flue gas desulfurization (WFGD) plants, focusing on oxy-coal combustion processes and differences when compared with atmospheres enriched in N2. The main drawback of using WFGD for mercury capture is the possibility of unwanted reduction of dissolved Hg(2+), leading to the re-emission of insoluble elemental mercury (Hg(0)), which decreases efficiency. To acquire a better understanding of the mercury re-emission reactions in WFGD systems, this work analyses different variables that influence the behavior of mercury in slurries obtained from two limestones, under an oxy-combustion atmosphere. The O2 supplied to the reactor, the influence of the pH, the concentration of mercury in the gas phase, and the enhancement of mercury in the slurry were the variables considered. The study was performed at laboratory scale, where possible reactions between the components in the scrubber can be individually evaluated. It was found that in an oxy-combustion atmosphere (mostly CO2), the re-emission of Hg(0) is lower than under a N2-enriched atmosphere, and the mercury is mainly retained as Hg(2+) in the liquid phase. PMID:27329988

  6. NOBLE GAS PRODUCTION FROM MERCURY SPALLATION AT SNS

    SciTech Connect

    DeVore, Joe R; Lu, Wei; Schwahn, Scott O

    2013-01-01

    Calculations for predicting the distribution of the products of spallation reactions between high energy protons and target materials are well developed and are used for design and operational applications in many projects both within DOE and in other arenas. These calculations are based on theory and limited experimental data that verifies rates of production of some spallation products exist. At the Spallation Neutron Source, a helium stream from the mercury target flows through a system to remove radioactivity from this mercury target offgas. The operation of this system offers a window through which the production of noble gases from mercury spallation by protons may be observed. This paper describes studies designed to measure the production rates of twelve noble gas isotopes within the Spallation Neutron Source mercury target.

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

    NASA Astrophysics Data System (ADS)

    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

  8. Target-induced formation of gold amalgamation on DNA-based sensing platform for electrochemical monitoring of mercury ion coupling with cycling signal amplification strategy.

    PubMed

    Chen, Jinfeng; Tang, Juan; Zhou, Jun; Zhang, Lan; Chen, Guonan; Tang, Dianping

    2014-01-31

    Heavy metal ion pollution poses severe risks in human health and environmental pollutant, because of the likelihood of bioaccumulation and toxicity. Driven by the requirement to monitor trace-level mercury ion (Hg(2+)), herein we construct a new DNA-based sensor for sensitive electrochemical monitoring of Hg(2+) by coupling target-induced formation of gold amalgamation on DNA-based sensing platform with gold amalgamation-catalyzed cycling signal amplification strategy. The sensor was simply prepared by covalent conjugation of aminated poly-T(25) oligonucleotide onto the glassy carbon electrode by typical carbodiimide coupling. Upon introduction of target analyte, Hg(2+) ion was intercalated into the DNA polyion complex membrane based on T-Hg(2+)-T coordination chemistry. The chelated Hg(2+) ion could induce the formation of gold amalgamation, which could catalyze the p-nitrophenol with the aid of NaBH4 and Ru(NH3)6(3+) for cycling signal amplification. Experimental results indicated that the electronic signal of our system increased with the increasing Hg(2+) level in the sample, and has a detection limit of 0.02nM with a dynamic range of up to 1000nM Hg(2+). The strategy afforded exquisite selectivity for Hg(2+) against other environmentally related metal ions. In addition, the methodology was evaluated for the analysis of Hg(2+) in spiked tap-water samples, and the recovery was 87.9-113.8%. PMID:24439499

  9. Effect of reticuloendothelial system blockade on the biotransformation of methyl mercury in the rat

    SciTech Connect

    Suda, Ikuo; Takahashi, Hitoshi )

    1990-04-01

    It has been reported that methyl mercury (MeHg) administered to animals is biotransformed to inorganic mercury. Several studies have presented that there are two degradation process, by intestinal microflora and by animal tissues themselves. In a previous paper, the authors reported the biotransformation of MeHg in the rat was enhanced by phenylhydrazine administration, and inhibited by splenectomy or treatment with carrageenan (CAR). They suggested that spleen and liver might be the important sites for formation of inorganic mercury, and that reticuloendothelial system (RES) cells in these organs might play a major role in this biotransformation. The clearance activity of RES cells, mainly located in the liver and spleen, can be depressed by saturating those cells with CAR, colloidal carbon (CC), trypan blue (TB), colloidal iron (CFe), dextran sulfate, silica. The purpose of this study is to confirm the relationship between RES function and biotransformation of MeHg by using four representative blockers, CC, TB, CFe and CAR. The inhibited biotransformation of MeHg in RES-blocker-treated rats was evaluated by measuring the amount of total and inorganic mercury in tissues. On the other hand, RES cell activity was measured by carbon clearance tests.

  10. Aviation spectral camera infinity target simulation system

    NASA Astrophysics Data System (ADS)

    Liu, Xinyue; Ming, Xing; Liu, Jiu; Guo, Wenji; Lv, Gunbo

    2014-11-01

    With the development of science and technology, the applications of aviation spectral camera becoming more widely. Developing a test system of dynamic target is more important. Aviation spectral camera infinity target simulation system can be used to test the resolution and the modulation transfer function of camera. The construction and work principle of infinity target simulation system were introduced in detail. Dynamic target generator based digital micromirror device (DMD) and required performance of collimation System were analyzed and reported. The dynamic target generator based on DMD had the advantages of replacing image convenient, size small and flexible. According to the requirement of tested camera, by rotating and moving mirror, has completed a full field infinity dynamic target test plan.

  11. Experiences in long-term evaluation of mercury emission monitoring systems

    SciTech Connect

    Chin-Min Cheng; Hung-Ta Lin; Qiang Wang; Chien-Wei Chen; Chia-Wei Wang; Ming-Chung Liu; Chi-Kuan Chen; Wei-Ping Pan

    2008-09-15

    Six mercury continuous emission monitoring (CEM) systems provided by two leading mercury (Hg) CEM system manufacturers were tested at five coal combustion utilities. The linearity, response time, day-to-day stability, efficiency of the Hg speciation modules, and ease of use were evaluated by following procedures specified in the Code of Federal Regulation Title 40 Part 75 (40 CFR Part 75). Mercury monitoring results from Hg CEM systems were compared to an EPA-recognized reference method. A sorbent trap sampling system was also evaluated in this study to compare the relative accuracy to the reference method as well as to Hg CEM systems. A conceptual protocol proposed by U.S. EPA (Method 30A) for using an Hg CEM system as the reference method for the Hg relative accuracy (RA) test was also followed to evaluate the workability of the protocol. This paper discusses the operational experience obtained from these field studies and the remaining challenges to overcome while using Hg CEM systems and the sorbent trap method for continuous Hg emission monitoring. 3 refs., 5 figs., 11 tabs.

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

    SciTech Connect

    Gary M. Blythe

    2002-02-22

    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 in a stable form 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 will test previously identified, effective catalyst materials at a larger, pilot scale and in a commercial form, so as to provide engineering data for future full-scale 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 first full reporting period for the subject Cooperative Agreement. During this period, most of the project efforts were related to project initiation and planning. There is no significant technical progress to report for the current period.

  13. Nanodelivery System for Mitochondrial Targeting

    NASA Astrophysics Data System (ADS)

    Yoong, Sia Lee; Pastorin, Giorgia

    2014-02-01

    Mitochondria are indispensable in cellular functions such as energy production and death execution. They are emerging as intriguing therapeutic target as their dysregulation was found to be monumental in diseases such as neurodegenerative disease, obesity, and cancer etc. Despite tremendous interest being focused on therapeutically intervening mitochondrial function, few mito-active drugs were successfully developed, particularly due to challenges in delivering active compound to this organelle. In this review, effort in utilizing nanotechnology for targeted mitochondrial delivery of compound is expounded based on the nature of the nanomaterial used. The advantage and potential offered are discussed alongside the limitation. Finally the review is concluded with perspectives of the application of nanocarrier in mitochondrial medicine, given the unresolved concern on potential complications.

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

    SciTech Connect

    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

  15. Degradation of methyl and ethyl mercury into inorganic mercury by oxygen free radical-producing systems: involvement of hydroxyl radical.

    PubMed

    Suda, I; Totoki, S; Takahashi, H

    1991-01-01

    Degradation of methyl mercury (MeHg) and ethyl Hg (EtHg) with oxygen free radicals was studied in vitro by using three well-known hydroxyl radical (.OH)-producing systems, namely Cu2(+)-ascorbate, xanthine oxidase (XOD)-hypoxanthine (HPX)-Fe(III)EDTA and hydrogen peroxide (H2O2)-ultraviolet light B. For this purpose, the direct determination method for inorganic Hg was employed. MeHg and EtHg were readily degraded by these three systems, though the amounts of inorganic Hg generated from MeHg were one half to one third those from EtHg. Degradation activity of XOD-HPX-Fe(III)EDTA system was inhibited by superoxide dismutase, catalase and the .OH scavengers and stimulated by H2O2. Deletion of the .OH formation promoter Fe(III)EDTA from XOD-HPX-Fe(III)EDTA system resulted in the decreased degradation of MeHg and EtHg, which was enhanced by further addition of the iron chelator diethylenetriamine pentaacetic acid. In all these cases, a good correlation was observed between alkyl Hg degradation and deoxyribose oxidation determining .OH. By contrast, their degradation appeared to be unrelated to either superoxide anion (O2-) production or H2O2 production alone. We further confirmed that H2O2 (below 2 mM) itself did not cause significant degradation of MeHg and EtHg. These results suggested that .OH, but not O2- and H2O2, might be the oxygen free radical mainly responsible for the degradation of MeHg and EtHg. PMID:1647758

  16. Cryogenic target system for hydrogen layering

    SciTech Connect

    Parham, T.; Kozioziemski, B.; Atkinson, D.; Baisden, P.; Bertolini, L.; Boehm, K; Chernov, A.; Coffee, K.; Coffield, F.; Dylla-Spears, R.; Edwards, O.; Fair, J.; Fedorov, M.; Fry, J.; Gibson, C.; Haid, B.; Holunga, D.; Kohut, T.; Lewis, T.; Malsbury, T.; Mapoles, E.; Sater, J.; Skulina, K.; Trummer, D.; Walters, C.

    2015-11-24

    Here, a cryogenic target positioning system was designed and installed on the National Ignition Facility (NIF) target chamber. This instrument incorporates the ability to fill, form, and characterize the NIF targets with hydrogen isotopes needed for ignition experiments inside the NIF target bay then transport and position them in the target chamber. This effort brought to fruition years of research in growing and metrologizing high-quality hydrogen fuel layers and landed it in an especially demanding operations environment in the NIF facility. D-T (deuterium-tritium) layers for NIF ignition experiments have extremely tight specifications and must be grown in a very highly constrained environment: a NIF ignition target inside a cryogenic target positioner inside the NIF target bay. Exquisite control of temperature, pressure, contaminant level, and thermal uniformity are necessary throughout seed formation and layer growth to create an essentially-groove-free single crystal layer.

  17. Cryogenic target system for hydrogen layering

    DOE PAGESBeta

    Parham, T.; Kozioziemski, B.; Atkinson, D.; Baisden, P.; Bertolini, L.; Boehm, K; Chernov, A.; Coffee, K.; Coffield, F.; Dylla-Spears, R.; et al

    2015-11-24

    Here, a cryogenic target positioning system was designed and installed on the National Ignition Facility (NIF) target chamber. This instrument incorporates the ability to fill, form, and characterize the NIF targets with hydrogen isotopes needed for ignition experiments inside the NIF target bay then transport and position them in the target chamber. This effort brought to fruition years of research in growing and metrologizing high-quality hydrogen fuel layers and landed it in an especially demanding operations environment in the NIF facility. D-T (deuterium-tritium) layers for NIF ignition experiments have extremely tight specifications and must be grown in a very highlymore » constrained environment: a NIF ignition target inside a cryogenic target positioner inside the NIF target bay. Exquisite control of temperature, pressure, contaminant level, and thermal uniformity are necessary throughout seed formation and layer growth to create an essentially-groove-free single crystal layer.« less

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

    NASA Astrophysics Data System (ADS)

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

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

    SciTech Connect

    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-based catalyst began with almost 98

  1. [Accumulation of Mercury in Soil-maize System of Non-ferrous Metals Smelting Area and Its Related Risk Assessment].

    PubMed

    Ji, Xiao-feng; Zheng, Na; Wang, Yang; Liu, Qiang; Zhang, Jing-jing

    2015-10-01

    Soil heavy metal pollution, especially the mercury pollution, has been widespread concern in non-ferrous metallurgical area. This study focused on the content, distribution and pollution status of Hg in maize soil of Huludao city. Meanwhile, Hg contents in the various organs of maize were analyzed. Hg concentration in soil ranged from 0.25 to 3.49 mg x kg(-1) with the average content of 1.78 mg x kg(-1), which was 48 times as high as the background value of Liaoning soil. Around 2-3m range of zinc plant, the pattern of spatial distribution showed that the content of Hg was gradually increased with the increase of the distance to Huludao zinc plant. The result of geoaccumulation index reflected that Hg pollution is up to moderate pollution level on the whole. 54. 6% of the total sample were belonged to the serious pollution level. The potential ecological risk index of Hakanson was applied to assess the ecological risk of Hg. The target hazard quotient method (THQ) was used to assess the health risk for human, the results revealed that there was no significant health risk by consumption corn. Mercury is very difficult to transport in soil-maize system, and there is no obvious health risks to adults. But the risk coefficient of children, which is up to 0.056. is much higher than adults. PMID:26841621

  2. An intelligent multi-target tracking system

    NASA Astrophysics Data System (ADS)

    Heyerdahl, E.

    1987-07-01

    An implementation of a general tracking system, integrating the target acquisition and tracking subsystems, was developed. It is based on image analysis and extensive use of models. The system permits improvements compared to in-service trackers in the sense that it enables multi-target tracking, automatic acquisition also during tracking and tracking through obscurations. The system is an implementation of a general tracking system. This system produces alternative estimates of a target and projects the corresponding objects into the image plane. To do this estimates of the projecting function are used. The different projections are synthesized through a thresholding process. The implemented system uses parallel Kalman filters to produce the object estimates and estimates the sensor position through a model of sensor dynamics and measurements of sensor angle velocity. Results, produced by the implemented system from IR imagery of a moving target in field are presented.

  3. Toxicity of mercury and mercury compounds. (Latest citations from Pollution Abstracts). Published Search

    SciTech Connect

    Not Available

    1993-02-01

    The bibliography contains citations concerning the toxic effects of mercury and mercury compounds on biological systems. The citations examine mercury halides, organic mercury compounds, mercury metal, and mercury vapor. Metabolism, toxicology, occupational exposure, symptoms of exposure, mechanisms of interaction with biological systems, demographics of mercury accumulation and poisoning, and case reports are considered. Heavy metal pollution and bioaccumulation are referenced in related bibliographies. (Contains 250 citations and includes a subject term index and title list.)

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

    SciTech Connect

    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 has an electrostatic

  5. A Rhizosphere-Associated Symbiont, Photobacterium spp. Strain MELD1, and Its Targeted Synergistic Activity for Phytoprotection against Mercury

    PubMed Central

    Mathew, Dony Chacko; Ho, Ying-Ning; Gicana, Ronnie Gicaraya; Mathew, Gincy Marina; Chien, Mei-Chieh; Huang, Chieh-Chen

    2015-01-01

    Though heavy metal such as mercury is toxic to plants and microorganisms, the synergistic activity between them may offer benefit for surviving. In this study, a mercury-reducing bacterium, Photobacterium spp. strain MELD1, with an MIC of 33 mg . kg-1 mercury was isolated from a severely mercury and dioxin contaminated rhizosphere soil of reed (Phragmites australis). While the whole genome sequencing of MELD1 confirmed the presence of a mer operon, the mercury reductase MerA gene showed 99% sequence identity to Vibrio shilloni AK1 and implicates its route resulted from the event of horizontal gene transfer. The efficiency of MELD1 to vaporize mercury (25 mg . kg-1, 24 h) and its tolerance to toxic metals and xenobiotics such as lead, cadmium, pentachlorophenol, pentachloroethylene, 3-chlorobenzoic acid, 2,3,7,8-tetrachlorodibenzo-p-dioxin and 1,2,3,7,8,9-hexachlorodibenzo-p-dioxin is promising. Combination of a long yard bean (Vigna unguiculata ssp. Sesquipedalis) and strain MELD1 proved beneficial in the phytoprotection of mercury in vivo. The effect of mercury (Hg) on growth, distribution and tolerance was examined in root, shoot, leaves and pod of yard long bean with and without the inoculation of strain MELD1. The model plant inoculated with MELD1 had significant increases in biomass, root length, seed number, and increased mercury uptake limited to roots. Biolog plate assay were used to assess the sole-carbon source utilization pattern of the isolate and Indole-3-acetic acid (IAA) productivity was analyzed to examine if the strain could contribute to plant growth. The results of this study suggest that, as a rhizosphere-associated symbiont, the synergistic activity between the plant and MELD1 can improve the efficiency for phytoprotection, phytostabilization and phytoremediation of mercury. PMID:25816328

  6. A rhizosphere-associated symbiont, Photobacterium spp. strain MELD1, and its targeted synergistic activity for phytoprotection against mercury.

    PubMed

    Mathew, Dony Chacko; Ho, Ying-Ning; Gicana, Ronnie Gicaraya; Mathew, Gincy Marina; Chien, Mei-Chieh; Huang, Chieh-Chen

    2015-01-01

    Though heavy metal such as mercury is toxic to plants and microorganisms, the synergistic activity between them may offer benefit for surviving. In this study, a mercury-reducing bacterium, Photobacterium spp. strain MELD1, with an MIC of 33 mg x kg(-1) mercury was isolated from a severely mercury and dioxin contaminated rhizosphere soil of reed (Phragmites australis). While the whole genome sequencing of MELD1 confirmed the presence of a mer operon, the mercury reductase MerA gene showed 99% sequence identity to Vibrio shilloni AK1 and implicates its route resulted from the event of horizontal gene transfer. The efficiency of MELD1 to vaporize mercury (25 mg x kg(-1), 24 h) and its tolerance to toxic metals and xenobiotics such as lead, cadmium, pentachlorophenol, pentachloroethylene, 3-chlorobenzoic acid, 2,3,7,8-tetrachlorodibenzo-p-dioxin and 1,2,3,7,8,9-hexachlorodibenzo-p-dioxin is promising. Combination of a long yard bean (Vigna unguiculata ssp. Sesquipedalis) and strain MELD1 proved beneficial in the phytoprotection of mercury in vivo. The effect of mercury (Hg) on growth, distribution and tolerance was examined in root, shoot, leaves and pod of yard long bean with and without the inoculation of strain MELD1. The model plant inoculated with MELD1 had significant increases in biomass, root length, seed number, and increased mercury uptake limited to roots. Biolog plate assay were used to assess the sole-carbon source utilization pattern of the isolate and Indole-3-acetic acid (IAA) productivity was analyzed to examine if the strain could contribute to plant growth. The results of this study suggest that, as a rhizosphere-associated symbiont, the synergistic activity between the plant and MELD1 can improve the efficiency for phytoprotection, phytostabilization and phytoremediation of mercury. PMID:25816328

  7. Mercury Lightcraft Project Update: 3-D Modeling, Systems Analysis and Integration

    NASA Astrophysics Data System (ADS)

    Buckton, Thomas W.; Myrabo, Leik N.

    2005-04-01

    This paper is a progress report on the laser-propelled Mercury Lightcraft Project at Rensselaer Polytechnic Institute. The laser-propelled, 1-person craft has a diameter of 252-cm, height of 217-cm, internal volume of 3 m3, `dry' mass of 700 kg, and gross liftoff mass of 1 metric ton. Expendable liquids including 70 kg of liquid hydrogen, and an equivalent mass (at least) of de-ionized water serves as open-cycle coolants for the 520 MWe laser/electric power conversion system. Its hyper-energetic airbreathing engine can easily accelerate the vehicle at 10 Gs or more. The tractor-beam lightcraft is intended as a prototype for use in a future global aerospace transportation system based on a constellation of satellite solar power stations in geostationary orbit, with laser relay stations in low Earth orbit. Using SolidWorks® 3-D modeling software, several important features were successfully integrated into the Mercury lightcraft model - principally: a rotating shroud (for spin stabilization) simple actuation system for a new variable-geometry air inlet; refined optical train for the laser-heated H2 plasma generators; pneumatically deployed, robotic quadra-pod landing gear; ejection seat/pod/hatch system; and a more detailed airframe structural concept. The CAD effort has brought the Mercury Lightcraft concept one significant step closer to reality.

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

    SciTech Connect

    Gary M. Blythe

    2002-04-26

    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 January 1, 2002 through March 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 in a stable form 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 will test previously identified, effective catalyst materials at a larger, pilot scale and in a commercial form, so as to provide engineering data for future full-scale 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 second full reporting period for the subject Cooperative Agreement. During this period, most of the project efforts were related to pilot unit design and conducting laboratory runs to help select candidate catalysts. This technical progress report provides an update on these two efforts. A Test Plan for the upcoming pilot-scale evaluations was also prepared and submitted to NETL for review and comment. Since this document was already submitted under separate cover, this

  9. Accident analysis of the windowless target system

    SciTech Connect

    Bianchi, F.; Ferri, R.

    2006-07-01

    Transmutation systems are able to reduce the radio-toxicity and amount of High-Level Wastes (HLW), which are the main concerns related to the peaceful use of nuclear energy, and therefore they should make nuclear energy more easily acceptable by population. A transmutation system consists of a sub-critical fast reactor, an accelerator and a Target System, where the spallation reactions needed to sustain the chain reaction take place. Three options were proposed for the Target System within the European project PDS-XADS (Preliminary Design Studies on an Experimental Accelerator Driven System): window, windowless and solid. This paper describes the constraints taken into account in the design of the windowless Target System for the large Lead-Bismuth-Eutectic cooled XADS and deals with the results of the calculations performed to assess the behaviour of the target during some accident sequences related to pump trips. (authors)

  10. Systemic targeted radionuclide therapy: Potential new areas

    SciTech Connect

    Wong, Jeffrey Y.C. . E-mail: jwong@coh.org

    2006-10-01

    Radiation oncology is entering an exciting new era with therapies being delivered in a targeted fashion through an increasing number of novel approaches. External beam radiotherapy now integrates functional and anatomic tumor imaging to guide delivery of conformal radiation to the tumor target. Systemic targeted radionuclide therapy (STaRT) adds an important new dimension by making available to Radiation oncologist biologically targeted radiation therapy. Impressive clinical results with antibody-targeted radiotherapy, leading to the Food and Drug Administration's approval of two anti-CD20 radiolabeled antibodies, highlight the potential of STaRT. Optimization strategies will further improve the efficacy of STaRT by improving delivery systems, modifying the tumor microenvironment to increase targeted dose, and maximizing dose effect. Ultimately, the greatest potential for STaRT will not be as monotherapy, but as therapy integrated into established multimodality regimens and used as adjuvant or consolidative therapy in patients with minimal or micrometastatic disease.

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Temperature Controller System for Gas Gun Targets

    NASA Astrophysics Data System (ADS)

    Bucholtz, S. M.; Gehr, R. J.; Rupp, T. D.; Sheffield, S. A.; Robbins, D. L.

    2006-07-01

    A temperature controller system capable of heating and cooling gas gun targets over the range -75°C to +120°C was designed and tested. The system uses cold nitrogen gas from a liquid nitrogen Dewar for cooling and compressed air for heating. Two gas flow heaters control the gas temperature for both heating and cooling. One heater controls the temperature of the target mounting plate and the other the temperature of a copper tubing coil surrounding the target. Each heater is separately adjustable, so the target material will achieve a uniform temperature throughout its volume. A magnetic gauge membrane with integrated thermocouples was developed to measure the internal temperature of the target. Using this system, multiple magnetic gauge shock experiments, including equation-of-state measurements and shock initiation of high explosives, can be performed over a range of initial temperatures. Successful heating and cooling tests were completed on Teflon samples.

  13. Summary of Mercury Compatibility Issues for the Spallation Neutron Source Target Containment and Ancillary Equipment

    SciTech Connect

    Pawel, SJ

    2003-04-08

    The purpose of this document is to summarize the primary results of the Hg compatibility research in support of the SNS target. In the absence of possible synergisms resulting from beam/irradiation effects, wetting of 316L/316LN stainless steel under SNS conditions by the Hg target is expected to be very limited. As a result, significant interactions such as dissolution, mass transfer, and embrittlement affecting general compatibility are not anticipated. A wide range of experiments on 316L/316LN stainless steel, including thermal convection and pumped loops, confirmed low corrosion/penetration rates in Hg up to 305 C and little or no wetting or mass transfer below about 250 C. A variety of standard mechanical tests comparing behavior of 316L in air and Hg revealed limited wetting and no degradation of mechanical properties such as reduced elongation or development of brittle fracture features. Preliminary fatigue tests indicated a negative effect (reduced cycles to failure and intergranular cracking) at very high loads for 316LN, but little or no effect at more modest loading. Annealed 316LN was found to be somewhat susceptible to cavitation-erosion damage, but significant improvement was realized with a kolsterizing surface treatment or coldworking the material. Within the scope of these test conditions, no compatibility-limited operations were identified for type 316L/316LN stainless steel (and variations thereof) as the Hg target containment material. More limited compatibility data on other materials are also reported.

  14. LED Systems Target Plant Growth

    NASA Technical Reports Server (NTRS)

    2010-01-01

    To help develop technologies for growing edible biomass (food crops) in space, Kennedy Space Center partnered with Orbital Technologies Corporation (ORBITEC), of Madison, Wisconsin, through the Small Business Innovation Research (SBIR) program. One result of this research was the High Efficiency Lighting with Integrated Adaptive Control (HELIAC) system, components of which have been incorporated into a variety of agricultural greenhouse and consumer aquarium lighting features. The new lighting systems can be adapted to a specific plant species during a specific growth stage, allowing maximum efficiency in light absorption by all available photosynthetic tissues.

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

    SciTech Connect

    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.

  16. Long-term changes in fish mercury levels in the historically impacted English-Wabigoon River system (Canada).

    PubMed

    Neff, Margaret R; Bhavsar, Satyendra P; Arhonditsis, George B; Fletcher, Rachael; Jackson, Donald A

    2012-09-01

    The English-Wabigoon River system in Northwestern Ontario, Canada, was one of the most heavily mercury-contaminated waterways in the world due to historical discharges in the 1960s from a chlor-alkali plant. This study examines long-term (1970-2010) monitoring data to assess temporal trends in mercury contamination in Walleye, Northern Pike and Lake Whitefish, three species important for sport and subsistence fishing in this region, using dynamic linear modeling and piecewise regression. For all lakes and species, there is a significant decline (36-94%) in mercury concentrations through time; however, there is evidence that this decline is either slowing down or levelling off. Concentrations in the English-Wabigoon fish are elevated, and may still present a potential health risk to humans consuming fish from this system. Various biotic and abiotic factors are examined as possible explanations to slowing rates of decline in mercury concentrations observed in the mid-1980s. PMID:22785387

  17. Magnetic confinement system using charged ammonia targets

    DOEpatents

    Porter, Gary D.; Bogdanoff, Anatoly

    1979-01-01

    A system for guiding charged laser targets to a predetermined focal spot of a laser along generally arbitrary, and especially horizontal, directions which comprises a series of electrostatic sensors which provide inputs to a computer for real time calculation of position, velocity, and direction of the target along an initial injection trajectory, and a set of electrostatic deflection means, energized according to a calculated output of said computer, to change the target trajectory to intercept the focal spot of the laser which is triggered so as to illuminate the target of the focal spot.

  18. Engineering aspects of the application of structural materials in the 5 MW-ESS-mercury-target

    SciTech Connect

    Guttek, B.

    1996-06-01

    A main problem of the ESS-Hg-target development and the design of the components of its primary Hg-circuit is the choice of structural materials. As designing, calculations and experiments with elected materials take time and are very costy, a preview on their successful application has to be done before as detailed as possible. One aspect on this is to have the knowledge of characteristics values of the structural material candidates under the occuring mechanical and thermal loads, irradiation, corrosion and erosion. Another point is the technology of engineering concerning the manufacturing, welding, surface treatment, and quality control of such parts and components under the demand to reach maximum lifetime.

  19. Targeting engineering synchronization in chaotic systems

    NASA Astrophysics Data System (ADS)

    Bhowmick, Sourav K.; Ghosh, Dibakar

    2016-07-01

    A method of targeting engineering synchronization states in two identical and mismatch chaotic systems is explained in detail. The method is proposed using linear feedback controller coupling for engineering synchronization such as mixed synchronization, linear and nonlinear generalized synchronization and targeting fixed point. The general form of coupling design to target any desire synchronization state under unidirectional coupling with the help of Lyapunov function stability theory is derived analytically. A scaling factor is introduced in the coupling definition to smooth control without any loss of synchrony. Numerical results are done on two mismatch Lorenz systems and two identical Sprott oscillators.

  20. Compositional variations in the inner solar system: Insights from interior modeling and spectroscopy of Mercury, the Moon and asteroids

    NASA Astrophysics Data System (ADS)

    Riner, Miriam A.

    Compositional variations between the planets of the inner solar system hold clues to the origin and evolution of terrestrial planets, but clues to their compositions are masked by processes such as magmatic activity, early magma oceans, and space weathering. The ferrous iron content of Mercury may be a particularly important clue to the degree to which material was radially mixed in the early solar system. This dissertation explores methods for determining the compositions of inner solar system rocky bodies, especially Mercury. Geophysical models for Mercury's interior, assuming a solid inner core and a molten outer core surrounded by a silicate mantle, show a wide range of plausible interior structures and compositions. These models provide context for interpreting future spacecraft data, especially from the MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) and Bepi-Colombo missions. Turning to planetary surfaces, laboratory spectra of opaque minerals present on the lunar surface and proposed candidate minerals on Mercury's surface are used to study magma oceans on the Moon and Mercury. Analysis of laboratory spectra of opaque oxides and lunar soils shows that ultraviolet-visible (UVVIS) color alone does not provide a useful diagnostic of titanium content in the lunar maria. The opaque oxide spectra are also used to consider the nature of the opaque components on Mercury. The global darkening agent responsible for Mercury's low albedo is unlikely to be any of the iron, titanium-bearing opaque minerals that are common on the Moon. However, these same minerals are consistent with the low-reflectance material exposed by some impact craters on Mercury's surface, consistent with a preserved cumulate pile from a low-iron magma ocean. Finally, a global survey of color variations on the asteroid 433 Eros, as measured by the Near Earth Asteroid Rendezvous (NEAR) mission is used to investigate surface processes on Eros and to assess the effects of

  1. The construction and testing of the portable Hg(2+) ultrasonic calibrator for the control of mercury speciation systems.

    PubMed

    Gorecki, Jerzy; Okonska, Anna

    2016-01-15

    During fuel combustion mercury, as Hg(0) and Hg(2+) forms, is emitted to the atmosphere. Effective reduction of mercury emission requires applying speciation systems for emission control and research. An important part of all mercury determination and speciation systems are the calibrators. Calibrators are responsible for the accuracy of mercury determination and, in consequence, the effective reduction of mercury emission. The aim of the work was to construct a portable HgCl2 calibrator. The purpose of the device was the control of mercury speciation systems for continuous measurements and study of HgCl2 sorption. As a result of previously conducted research, the portable Hg(2+) ultrasonic calibrator was designed, constructed and tested. The ultrasonic calibrator generates a stable stream of HgCl2 (RSD=2.8% for CHg=28µg/m(3)). The correlation between theoretical and reading concentration of HgCl2 was R(2)=0.9983. The average recovery of HgCl2 was 95%. The advantages of the ultrasonic Hg(2+) calibrator are: high accuracy and selectivity, low pressure of HgCl2 stream and very low cost of production. The calibrator was successfully tested, both in the laboratory and in the power plant, during a preliminary study on HgCl2 sorption on a fly ash filter. PMID:26592572

  2. Planned flight test of a mercury ion auxiliary propulsion system. II - Integration with host spacecraft

    NASA Technical Reports Server (NTRS)

    Knight, R. M.

    1978-01-01

    This is part II of a three-part paper describing the approved flight test of a mercury ion auxiliary propulsion system. The objectives of the flight test are summarized with reference to user application. The approach to accomplishment is presented as it applies to integrating the propulsion system with the host spacecraft, USAF's STP P80-1. A number of known interface design considerations which affect the propulsion system and the spacecraft are discussed. Finally, analogies are drawn comparing the relationship of the organizations involved with this flight test with those anticipated for future operational missions. Attention is given to the viewpoint of the project office

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

    NASA Astrophysics Data System (ADS)

    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

  4. Allegany Ballistics Lab: sensor test target system

    NASA Astrophysics Data System (ADS)

    Eaton, Deran S.

    2011-06-01

    Leveraging the Naval Surface Warfare Center, Indian Head Division's historical experience in weapon simulation, Naval Sea Systems Command commissioned development of a remote-controlled, digitally programmable Sensor Test Target as part of a modern, outdoor hardware-in-the-loop test system for ordnance-related guidance, navigation and control systems. The overall Target system design invokes a sciences-based, "design of automated experiments" approach meant to close the logistical distance between sensor engineering and developmental T&E in outdoor conditions over useful real world distances. This enables operating modes that employ broad spectrum electromagnetic energy in many a desired combination, variably generated using a Jet Engine Simulator, a multispectral infrared emitter array, optically enhanced incandescent Flare Simulators, Emitter/Detector mounts, and an RF corner reflector kit. As assembled, the recently tested Sensor Test Target prototype being presented can capably provide a full array of useful RF and infrared target source simulations for RDT&E use with developmental and existing sensors. Certain Target technologies are patent pending, with potential spinoffs in aviation, metallurgy and biofuels processing, while others are variations on well-established technology. The Sensor Test Target System is planned for extended installation at Allegany Ballistics Laboratory (Rocket Center, WV).

  5. Conversion of elemental mercury with a novel membrane delivery catalytic oxidation system (MDCOs).

    PubMed

    Guo, Yongfu; Yan, Naiqiang; Yang, Shijian; Qu, Zan; Wu, Zhongbiao; Liu, Yue; Liu, Ping; Jia, Jinping

    2011-01-15

    In order to overcome the shortcomings of the traditional catalytic oxidation (TCO) mode for the conversion of the trace level of elemental mercury (Hg(0)) in flue gas, we put forward a novel and unique assembly that integrated membrane delivery with catalytic oxidation systems (MDCOs), which combined the controlled delivery of oxidants with the catalytic oxidation of Hg(0). The results show that the demanded HCl for Hg(0) conversion in the MDCOs was less than 5% of that in the TCO mode, and over 90% of Hg(0) removal efficiency can be obtained in the MDCOs with less than 0.5 mg m(-3) of HCl escaped. Meanwhile, the inhibition of SO(2) to Hg(0) catalytic conversion in the MDCOs was also less significant than in the TCO. The MDCOs have high retainability for HCl, which is quite favorable to Hg(0) conversion and HCl utilization. The reaction mechanism on mercury conversion in the MDCOs is discussed. The MDCOs appear to be a promising method for emission control of elemental mercury. PMID:21158439

  6. RECOVERY OF MERCURY FROM CONTAMINATED PRIMARY AND SECONDARY WASTES

    SciTech Connect

    A. Faucette; J. Bognar; T. Broderick; T. Battaglia

    2000-01-13

    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 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, a 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. Four new sorbents have been developed 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 demonstrated very high removal efficiencies for soluble mercury species, with mercury concentrations at the outlet of a pilot-scale system less than 12 ppt for as long as six months. The other sorbent tested at the Y-12 Plant is targeted at colloidal mercury that is 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 magnetic field was evaluated. Field results indicate good removal of this mercury fraction from the Y-12 waters. In addition, this sorbent is easily regenerated by simply removing the magnetic field and flushing the columns with water. The fourth sorbent is still undergoing laboratory development, but results to date indicate exceptionally high mercury sorption capacity. The sorbent is capable of removing all forms of mercury typically present in natural and

  7. Revealing Mercury

    NASA Astrophysics Data System (ADS)

    Prockter, L. M.; Solomon, S. C.; Head, J. W.; Watters, T. R.; Murchie, S. L.; Robinson, M. S.; Chapman, C. R.; McNutt, R. L.

    2009-04-01

    -frequency distribution suggest that smooth plains on Mercury's surface range in age from the end of the period of heavy impact bombardment to as young as perhaps 1 billion years; these ongoing measurements are helping to elucidate the volcanic history of the planet. Mercury's global tectonic history is also revealed by the MESSENGER image and laser altimeter data. Significant evidence for global contraction was seen in Mariner 10 images in the form of widespread lobate scarps. The MESSENGER images show that contractional features are the dominant tectonic landform globally, and the inferred average contractional strain is at least one third greater than previously inferred from Mariner 10 observations. Only three exceptions to the dominance of contractional deformation have been found to date: extensional troughs that include prominent basin-radial systems documented in two basins, the Pantheon Fossae within the 1500-km-diameter Caloris basin and a similar set of features within a newly-imaged 700-km-diameter basin, and a circumferential trough system within the smaller, younger Raditladi basin. That these extensional tectonic features are rare on Mercury, and that they are not seen within basins elsewhere in the Solar System, pose important constraints on the thermal and mechanical evolution of Mercury's interior.

  8. Design of the NIF Cryogenic Target System

    SciTech Connect

    Gibson, C; Baltz, J; Malsbury, T; Atkinson, D; Brugmann, V; Coffield, F; Edwards, O; Haid, B; Locke, S; Shiromizu, S; Skulina, K

    2008-06-10

    The United States Department of Energy has embarked on a campaign to conduct credible fusion ignition experiments on the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in 2010. The target assembly specified for this campaign requires the formation of a deuterium/tritium (DT) fuel ice layer in a 2 mm diameter capsule at the center of a 9 mm long by 5 mm diameter cylinder, called a hohlraum. The ice layer must be formed and maintained at temperatures below 20 K. At laser shot time, the target is positioned at the center of the NIF target chamber, aligned to the laser beams and held stable to less than 7 {micro}m rms. We have completed the final design of the Cryogenic Target System and are integrating the devices necessary to create, characterize and position the cryogenic target for ignition experiments. These designs, with supporting analysis and prototype test results, will be presented.

  9. Evaporation of mercury impurity from liquid lead-bismuth eutectic

    NASA Astrophysics Data System (ADS)

    Aerts, A.; Danaci, S.; Gonzalez Prieto, B.; Van den Bosch, J.; Neuhausen, J.

    2014-05-01

    The equilibrium evaporation of mercury from dilute solutions in liquid lead-bismuth eutectic (LBE) was studied in argon atmosphere. Mercury present as impurity in LBE was evaporated and detected by atomic fluorescence spectroscopy. A method which could accurately simulate the experimental data was developed. Coefficients of the Henry constant temperature correlation for mercury dissolved in LBE were determined. Experiments with samples from several different batches of LBE revealed that mercury at mole fractions between 10-6 and 10-12 and temperatures between 150 and 350 °C evaporated from liquid LBE close to ideal behavior. Evaporation of mercury from solid LBE on the other hand was unexpectedly high. These results are important for safety evaluations of LBE based spallation targets and accelerator driven systems.

  10. The effects of a stannous chloride-based water treatment system in a mercury contaminated stream

    SciTech Connect

    Mathews, Teresa J.; Looney, Brian B.; Smith, John G.; Miller, Carrie L.; Peterson, Mark J.; Bryan, A. Lawrence; Southworth, George R.

    2015-06-09

    Remediation of mercury (Hg)-contaminated watersheds is often challenging because of the complex nature of Hg biogeochemistry. Stream ecosystems have been shown to be particularly susceptible to Hg contamination and bioaccumulation in fish. Decreasing total Hg loading to stream systems, however, has shown variable performance in decreasing Hg concentrations in fish tissues. In this study, we assess the impacts of an innovative treatment system in reducing releases of Hg to a small stream system in the southeastern United States. The treatment system, installed in 2007, removes Hg from water using tin (Sn) (II) chloride followed by air stripping. Mercury concentrations in the receiving stream, Tims Branch, decreased from > 100 to ~10 ng/L in the four years following treatment, and Hg body burdens in redfin pickerel (Esox americanus) decreased by 70 % at the most contaminated site. Tin concentrations in water and fish increased significantly in the tributary leading to Tims Branch, but concentrations remain below levels of concern for human health or ecological risks. While other studies have shown that Sn may be environmentally methylated and methyltin can transfer its methyl group to Hg, results from our field studies and sediment incubation experiments suggest that the added Sn to the Tims Branch watershed is not contributing to MeHg production and bioaccumulation. The stannous chloride treatment system installed at Tims Branch was effective at removing Hg inputs and reducing Hg bioaccumulation in the stream with minimal impacts on the environment due to the increased Sn in the system.

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Inhalation uptake of low level elemental mercury vapor and its tissue distribution in rats

    SciTech Connect

    Oberski, S.P.; Fang, S.C.

    1980-07-01

    Elemental mercury vapor is the major component of mercury found in the atmosphere. Furthermore, if usage of coal is increased to meet the energy demand, then atmospheric levels of mercury are expected to rise. Current atmospheric concentrations of mercury vapor over select urban areas of the United States range from 0.5 to 50 ng m/sup -3/ with a mean of 7 ng m/sup -3/. Mercury concentration in brain tissue following inhalation of elemental mercury is significantly higher than those from intravenous injection or oral administration of either organic or ionic mercurials. Although elemental mercury is rapidly oxidized in the blood to the less diffusable mercuric ion, the transient occurrence of elemental mercury in the blood stream and the increased levels detected in the central nervous system are likely a result of its rapid diffusion into target tissues. This study reports the inhalation uptake and consequent tissue distribution of radioactive elemental mercury vapor in rats over a concentration range of 15 to 916 ng m/sup -3/, with particular emphasis on measurement below 50 ng m/sup -3/, in an effort to determine if the tissue distribution of mercury after a low level exposure is similar to those reported using higher concentrations.

  13. Pallidal targeting with the COMPASS system.

    PubMed

    Alterman, R L; Kall, B; Beric, A; Sterio, D; Kelly, P J

    1997-01-01

    The authors describe their initial experience with the new pallidotomy targeting software for the COMPASS system. As COMPASS permits window and contrast settings to be changed at any time, multiple imaging modalities can be employed for targeting. This feature allowed the incorporation of fast-spin echo/inversion recovery (FSE/IR) magnetic resonance images (MRI) into the planning protocol. COMPASS has now been employed for 33 consecutive pallidotomies over the last year (July 96-June 97). A statistically significant reduction in the number of microelectrode recording trajectories required to physiologically localize sensorimotor globus pallidus interna (GPi) is noted in these cases as compared to the 41 cases performed in the previous year with a different computer planning system. The authors conclude that the COMPASS system accurately and efficiently targets the internal pallidum when FSE/IR MRI is employed. Nevertheless, pallidotomy should not be performed without neurophysiological localization. PMID:9711736

  14. Eight-cm mercury ion thruster system technology

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The technology status of 8 cm diameter electron bombardment ion thrusters is presented. Much of the technology resulting from the 5 cm diameter thruster has been adapted and improved upon to increase the reliability, durability, and efficiency of the 8 cm thruster. Technology discussed includes: dependence of neutralizer tip erosion upon neutralizer flow rate; impregnated and rolled-foil insert cathode performance and life testing; neutralizer position studies; thruster ion beam profile measurements; high voltage pulse ignition; high utilization ion machined accelerator grids; deposition internal and external to the thruster; thruster vectoring systems; thruster cycling life testing and thruster system weights for typical mission applications.

  15. Systemic Targeted Alpha Radiotherapy for Cancer

    PubMed Central

    Allen, BJ

    2013-01-01

    Background: The fundamental principles of internal targeted alpha therapy forcancer were established many decades ago.The high linear energy transfer (LET) ofalpha radiation to the targeted cancer cellscauses double strand breaks in DNA. Atthe same time, the short range radiation spares adjacent normal tissues. This targeted approach complements conventional external beam radiotherapy and chemotherapy. Such therapies fail on several fronts, such as lack of control of some primary cancers (e.g. glioblastoma multiforme) and to inhibit the development of lethal metastaticcancer after successful treatment of the primary cancer. Objective: This review charts the developing role of systemic high LET, internalradiation therapy. Method: Targeted alpha therapy is a rapidly advancing experimental therapy thatholds promise to deliver high cytotoxicity to targeted cancer cells. Initially thoughtto be indicated for leukemia and micrometastases, there is now evidence that solidtumors can also be regressed. Results: Alpha therapy may be molecular or physiological in its targeting. Alphaemitting radioisotopes such as Bi-212, Bi-213, At-211 and Ac-225 are used to labelmonoclonal antibodies or proteins that target specific cancer cells. Alternatively, Radium-233 is used for palliative therapy of breast and prostate cancers because of its bone seeking properties. Conclusion: Preclinical studies and clinical trials of alpha therapy are discussedfor leukemia, lymphoma, melanoma, glioblastoma multiforme, bone metastases, ovarian cancer, pancreatic cancer and other cancers. PMID:25505750

  16. A Pion Production and Capture System for a 4 MW Target Station

    SciTech Connect

    Ding, X.; Kirk, H.; Berg, J.S.

    2010-06-01

    A study of a pion production and capture system for a 4 MW target station for a neutrino factory or muon collider is presented. Using the MARS code, we simulate the pion production produced by the interaction of a free liquid mercury jet with an intense proton beam. We study the variation of meson production with the direction of the proton beam relative to the target. We also examine the influence on the meson production by the focusing of the proton beam. The energy deposition in the capture system is determined and the shielding required in order to avoid radiation damage is discussed. The exploration for the multiple proton beam entry directions relative to mercury jet in the 8GeV proton beam case demonstrates that an asymmetric layout is required in order to achieve the same beam/jet crossing angle at the jet axis. We find a correlation between the distance of beam relative to the jet and the meson production. The peak meson production is 8% higher than for the lowest case. The examination of the influence on the meson production by the focusing of the proton beam shows the meson production loss is negligible (<1%) for a beta function to be 0.3m or higher for the proton beam. By investigating the energy deposition in the target/capture system, we see that the bulk of 4-MW proton beam power is deposited in the water cooled tungsten-carbide (WC) shielding, the mercury jet and the capture beam pipe. In addition, high power deposition in the first superconducting coil causes an issue for its operation and life time. Enhanced shielding is necessary to lower the radiation damage.

  17. ENHANCED CONTROL OF MERCURY BY WET FLUE GAS DESULFURIZATION SYSTEMS--SITE 2 RESULTS

    SciTech Connect

    G. Blythe; S. Miller; C. Richardson; K. Searcy

    2000-02-01

    The U.S. Department of Energy and EPRI are co-funding this project to improve the control of mercury emissions from coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems. The project is investigating catalytic oxidation of vapor-phase elemental mercury to a form that is more effectively captured in wet FGD systems. If successfully developed, the process could be applicable to over 90,000 MW of utility generating capacity with existing FGD systems, and to future FGD installations. Field tests are being conducted to determine whether candidate catalyst materials remain active towards mercury oxidation after extended flue gas exposure. Catalyst life will have a large impact on the cost effectiveness of this potential process. A mobile catalyst test unit is being used to test the activity of four different catalysts for a period of up to six months at each of three utility sites. Catalyst testing at the first site, which fires Texas lignite, was completed in December 1998. Testing at the second test site, which fires a Powder River Basin subbituminous coal, was completed in the fall of 1999, and testing at the third site, which fires a high-sulfur bituminous coal, will begin in early 2000. This technical note reports results from Site 2; results from Site 1 were reported in a previous technical note. At Site 2, catalysts were tested in several forms, including powders dispersed in sand bed reactors and in more commercially viable forms such as extruded beads and coated honeycomb structures. This technical note presents results from Site 2 for both the sand bed reactors and commercial catalyst forms. Site 3 results are not yet available, but should be available late in the year 2000. Field testing is being supported by laboratory tests to screen catalysts for activity at specific flue gas compositions, to investigate catalyst deactivation mechanisms and to investigate methods for regenerating spent catalysts. Laboratory results related to the

  18. ENHANCED CONTROL OF MERCURY BY WET FLUE GAS DESULFURIZATION SYSTEMS--SITE 2 RESULTS

    SciTech Connect

    G. Blythe; S. Miller; C. Richardson; K. Searcy

    2000-06-01

    The U.S. Department of Energy and EPRI are co-funding this project to improve the control of mercury emissions from coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems. The project is investigating catalytic oxidation of vapor-phase elemental mercury to a form that is more effectively captured in wet FGD systems. If successfully developed, the process could be applicable to over 90,000 MW of utility generating capacity with existing FGD systems, and to future FGD installations. Field tests are being conducted to determine whether candidate catalyst materials remain active towards mercury oxidation after extended flue gas exposure. Catalyst life will have a large impact on the cost effectiveness of this potential process. A mobile catalyst test unit is being used to test the activity of four different catalysts for a period of up to six months at each of three utility sites. Catalyst testing at the first site, which fires Texas lignite, was completed in December 1998. Testing at the second test site, which fires a Powder River Basin subbituminous coal, was completed in the fall of 1999, and testing at the third site, which fires a high-sulfur bituminous coal, will begin in 2000. This technical note reports results from Site 2; results from Site 1 were reported in a previous technical note. At Site 2, catalysts were tested in several forms, including powders dispersed in sand bed reactors and in commercial forms such as extruded beads and coated honeycomb structures. This technical note presents results from Site 2 for both the sand bed reactors and commercial catalyst forms. Field testing is being supported by laboratory tests to screen catalysts for activity at specific flue gas compositions, to investigate catalyst deactivation mechanisms and to investigate methods for regenerating spent catalysts. Laboratory results related to the Site 2 field effort are also included and discussed in this technical note. Preliminary economics, based

  19. Temperature Controller System for Gas Gun Targets

    NASA Astrophysics Data System (ADS)

    Bucholtz, Scott; Sheffield, Stephen

    2005-07-01

    A temperature controller system capable of heating and cooling gas gun targets over the range -75 C to +200 C was designed and tested. The system uses cold nitrogen gas from a liquid nitrogen Dewar for cooling and compressed air for heating. Two gas flow heaters control the gas temperature for both heating and cooling. One heater controls the temperature of the target mounting plate and the other the temperature of a copper tubing coil surrounding the target. Each heater is separately adjustable, so the target material will achieve a uniform temperature throughout its volume. A magnetic gauge with integrated thermocouples was developed to measure the internal temperature of the target. Using this system shock experiments, including equation-of-state measurements and shock initiation of high explosives, can be performed over a range of initial temperatures. Successful tests were completed on Teflon samples. This work was supported by the NNSA Enhanced Surveillance Campaign through contract DE-ACO4-01AL66850.

  20. AN ELECTROCHEMICAL SYSTEM FOR REMOVING AND RECOVERING ELEMENTAL MERCURY FROM FLUE-STACK GASES

    EPA Science Inventory

    the impending EPA regulations on the control of mercury emissions from the flue stacks of coal-burning electric utilities has resulted in heightened interest in the development of advanced mercury control technologies such as sorbent injection and in-situ mercury oxidation. Altho...

  1. MPF model ages of the Rembrandt basin and scarp system, Mercury.

    NASA Astrophysics Data System (ADS)

    Ferrari, Sabrina; Massironi, Matteo; Marchi, Simone; Byrne, Paul K.; Klimczak, Christian; Cremonese, Gabriele

    2013-04-01

    The 715-km-diameter Rembrandt basin is the largest well-preserved impact feature of the southern hemisphere of Mercury [1] (Fig. 1), and was imaged for the first time during the second flyby of the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission [2]. Much of the basin interior is covered by smooth, high-reflectance plains interpreted to be of volcanic origin [1-3] that host sets of contractional and extensional tectonic structures. Notably, Rembrandt basin and its smooth plains are cross-cut by a 1,000-km-long reverse fault system [1-5] that trends ~E-W, bending toward the north within the basin. The individual faults of this system accommodated crustal shortening that resulted from global contraction as Mercury's interior cooled [1]. The current shape of the reverse fault system may have been influenced by the formation of the Rembrandt basin [5]. The emplacement of the interior smooth plains predates both the basin-related tectonism and the final development of the giant scarp, which is suggestive of either short-lived volcanic activity immediately after basin formation or a later volcanic phase set against prolonged tectonic activity. In order to quantify the duration of volcanic and tectonic activity in and around Rembrandt basin, we determined the crater count-derived ages of the involved terrains by means of the Model Production Function (MPF) chronology of Mercury [6-8], which is rely on the knowledge of the impactors flux on the planet. Crater chronology allowed us to constrain the Rembrandt basin formation to the early Calorian period and a widespread resurfacing up to 3.5 Ga ago. The volcanic activity affected both the basin and its surroundings, but ended prior to some basin-related and regional faulting. Hence, if the giant scarp begun to develop even before the basin formation (as suggested by its length-displacement profile across the basin itself, [5]) the regional tectonic activity along this structure might have

  2. Development of an autonomous target tracking system

    NASA Astrophysics Data System (ADS)

    Gidda, Venkata Ramaiah

    In recent years, surveillance and border patrol have become one of the key research areas in UAV research. Increase in the computational capability of the computers and embedded electronics, coupled with compatibility of various commercial vision algorithms and commercial off the shelf (COTS) embedded electronics, and has further fuelled the research. The basic task in these applications is perception of environment through the available visual sensors like camera. Visual tracking, as the name implies, is tracking of objects using a camera. The process of autonomous target tracking starts with the selection of the target in a sequence of video frames transmitted from the on-board camera. We use an improved fast dynamic template matching algorithm coupled with Kalman Filter to track the selected target in consecutive video frames. The selected target is saved as a reference template. On the ground station computer, the reference template is overlaid on the live streaming video from the on-board system, starting from the upper left corner of the video frame. The template is slid pixel by pixel over the entire source image. A comparison of the pixels is performed between the template and source image. A confidence value R of the match is calculated at each pixel. Based on the method used to perform the template matching, the best match pixel location is found according to the highest or lowest confidence value R. The best match pixel location is communicated to the on-board gimbal controller over the wireless Xbee network. The software on the controller actuates the pan-tilt servos to continuously to hold the selected target at the center of the video frame. The complete system is a portable control system assembled from commercial off the shelf parts. The tracking system is tested on a target having several motion patterns.

  3. Mineralogical Associations of Mercury in FGD Products

    SciTech Connect

    Beatty, William Lee; Schroeder, Karl; Beatty, Candace L. Kairies

    2012-06-21

    The natural mode of retention of mercury in flue gas desulfurization gypsum used in wallboard manufacturing has been investigated using a series of phase-targeted reagents. Results indicate that mercury was associated with two distinct phases.

  4. Colorimetric detection of mercury ion based on unmodified gold nanoparticles and target-triggered hybridization chain reaction amplification

    NASA Astrophysics Data System (ADS)

    Wang, Qing; Yang, Xiaohan; Yang, Xiaohai; Liu, Pei; Wang, Kemin; Huang, Jin; Liu, Jianbo; Song, Chunxia; Wang, Jingjing

    2015-02-01

    A novel unmodified gold nanoparticles (AuNPs)-based colorimetric strategy for label-free, specific and sensitive mercury ion (Hg2+) detection was demonstrated by using thymine-Hg2+-thymine (T-Hg2+-T) recognition mechanism and hybridization chain reaction (HCR) amplification strategy. In this protocol, a structure-switching probe (H0) was designed to recognize Hg2+ and then propagated a chain reaction of hybridization events between two other hairpin probes (H1 and H2). In the absence of Hg2+, all hairpin probes could stably coexist in solution, the exposed sticky ends of hairpin probes were capable of stabilizing AuNPs. As a result, salt-induced AuNPs aggregation could be effectively prevented. In the presence of Hg2+, thymine bases of H0 could specifically interact with Hg2+ to form stable T-Hg2+-T complex. Consequently, the hairpin structure of H0 probe was changed. As H1/H2 probes were added, the HCR process could be triggered and nicked double-helixes were formed. Since it was difficult for the formed nicked double-helixes to inhibit salt-induced AuNPs aggregation, a red-to-blue color change was observed in the colloid solution as the salt concentration increased. With the elegant amplification effect of HCR, a detection limit of around 30 nM was achieved (S/N = 3), which was about 1-2 orders of magnitudes lower than that of previous unmodified AuNPs-based colorimetric methods. By using the T-Hg2+-T recognition mechanism, high selectivity was also obtained. As an unmodified AuNPs-based colorimetric strategy, the system was simple in design, convenient in operation, and eliminated the requirements of separation processes, chemical modifications, and sophisticated instrumentations.

  5. ATMOSPHERIC MERCURY TRANSPORT AND DEPOSITION

    EPA Science Inventory

    The current state of our scientific understanding the mercury cycle tells us that most of the mercury getting into fish comes from atmospheric deposition, but methylation of that mercury in aquatic systems is required for the concentrations in fish to reach harmful levels. We st...

  6. Progress in ISOL target ion source systems

    NASA Astrophysics Data System (ADS)

    Köster, U.; Arndt, O.; Bouquerel, E.; Fedoseyev, V. N.; Frånberg, H.; Joinet, A.; Jost, C.; Kerkines, I. S. K.; Kirchner, R.; Targisol Collaboration

    2008-10-01

    The heart of every ISOL (isotope separation on-line) facility is its target and ion source system. Its efficiency, selectivity and rapidity is decisive for the production of intense and pure ion beams of short-lived isotopes. Recent progress in ISOL target and ion source technology is discussed at the examples of radioactive ion beams of exotic zinc and tin isotopes that were purified by isothermal chromatography and molecular sideband separation respectively. An outlook is given to which other elements these purification methods are applicable.

  7. Transits of Venus and Mercury: Exoplanet Analogs in Our Solar System

    NASA Astrophysics Data System (ADS)

    Pasachoff, Jay M.

    2012-05-01

    Since Johannes Kepler's predictions of transits of Mercury and Venus in 1631, and observations by Jeremiah Horrocks and William Crabtree of the 1639 transit of Venus, only 5 other transits of Venus have been observed: in 1761 and 1769, 1874 and 1882, and 2004. Expeditions were sent all over the world for the 18th and 19th century transits to follow the methods of Halley and others to determine the Astronomical Unit, giving the size and scale of the solar system, arguably the most important problem in astronomy for centuries. I will discuss how the infamous black-drop effect bedeviled astronomers in that quest for an accurate A.U., and how Glenn Schneider and I explained the effect through satellite observations of transits of Mercury, showing that it was not simply caused by the Cytherean atmosphere. During the 2004 transit, we worked with Richard Willson of ACRIMsat to detect the 0.1% drop in the Total Solar Irradiance, showing the effect of solar limb darkening, positioning such observations of transits of Venus and of Mercury as analogs to exoplanet transits. Our observations of the atmosphere of Venus with NASA's Transition Region and Coronal Explorer in 2004 led us to plan extensive observations of Venus's atmosphere and other phenomena during the June 5, 2012, transit of Venus, the last to be visible from Earth until 2117. We will have used NASA's Solar Dynamics Observatory, Hinode, ACRIMsat, and other spacecraft, and ground-based solar telescopes at Sacramento Peak, Kitt Peak, Big Bear, and Haleakala to observe the transit; I hope to give preliminary reports on these observations during this talk. Further, I will discuss the plans of Ehrenreich and colleagues for Hubble observations of this transit and our hopes of detecting transits of Venus and Earth as seen from Jupiter and Saturn over the next few years.

  8. Estimates of ground-level mercury vapor concentrations from postulated launch-pad accidents of NASA space transportation systems

    NASA Technical Reports Server (NTRS)

    Dumbauld, R. K.; Rafferty, J. E.; Saterlie, S. F.

    1978-01-01

    NASA has considered the use of mercury ion bombardment engines as extra-terrestrial propulsion systems where low thrust must be provided for long periods of time. However, the mercury fuel in these engines may pose a hazard if it is accidentally released to the troposphere. A description is presented of diffusion-model estimates of maximum 10-minute and 24-hour ground-level concentrations that could result from the accidental release of mercury from Titan/Centaur and Space Shuttle/Tug transportation systems. Three types of accidental release modes have been considered in the concentration calculations. For all three modes, the diffusion-model calculations were made for a variety of meteorological conditions in an effort to obtain estimates of the maximum credible concentrations under 'worst-case' conditions.

  9. Particle production of a graphite target system for the intensity frontier

    SciTech Connect

    Ding, X.; Kirk, H.; McDonald, K. T.

    2015-05-03

    A solid graphite target system is considered for an intense muon and/or neutrino source in support of physics at the intensity frontier. We previously optimized the geometric parameters of the beam and target to maximize particle production at low energies by incoming protons with kinetic energy of 6.75 GeV and an rms geometric emittance of 5 mm-mrad using the MARS15(2014) code. In this study, we ran MARS15 with ROOT-based geometry and also considered a mercury-jet target as an upgrade option. The optimization was extended to focused proton beams with transverse emittances from 5 to 50 mm-mrad, showing that the particle production decreases slowly with increasing emittance. We also studied beam-dump configurations to suppress the rate of undesirable high-energy secondary particles in the beam.

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

    PubMed Central

    Crowe, William; Doherty, Leanne; Watson, Gene; Armstrong, David; Ball, Elisabeth; Magee, Pamela; Allsopp, Philip; Bell, Aubrey; Strain, J. J.; McSorley, Emeir

    2015-01-01

    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. PMID:26703710

  11. Method for the removal and recovery of mercury

    DOEpatents

    Easterly, C.E.; Vass, A.A.; Tyndall, R.L.

    1997-01-28

    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.

  12. Method for the removal and recovery of mercury

    DOEpatents

    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.

  13. Task 2.8 - Mercury Speciation and Capture in Scubber Solutions

    SciTech Connect

    Sumitra R. Ness

    1997-08-01

    U.S. Environmental Protection Agency (EPA) investigation into health risks associated with mercury emissions from utility steam generators, municipal waste combustion units, and other sources was mandated by the Clean Air Act Amendments (CAAA) of 1990. In anticipation of mercury emission regulation, attention has been focused on quantification of mercury emissions, which require verifiable sampling and analytical techniques. Several sampling and analytical methods are currently under the final stages of development as well as a variety of emission control methods. In particular, wet scrubber systems designed for S2 control in coal-fired utilities have been targeted for mercury control. Conventional wet-scrubbers remove mercury in a variety of soluble oxidized forms. Oxidized mercury is highly water-soluble and can be removed by scrubber slurry, theoretically limited only by gas-film mass transfer. However, since some oxidized mercury forms such as HgClz are borh soluble and volatile, the final fate of mercury trapped in scrubber solutions is unclear. Elemental mercury is not water-soluble, remaining in the vapor state at temperatures through pollution control devices and exiting the stack into the environment. However, notable exceptions to this rule exist. Depending on the type of mercury-sampling method used, an increase ofs 10% in elemental mercury concentrations across wet scrubbers has been metiured but is yet unconllrmed. Also, significant amounts of elemental mercury (metallic form) have been removed during wet scrubber maintenance. In addition, questions concerning 1) the initial speciation between oxidized and elemental forms of mercury in flue gas from coal- fired boilers and 2) the effects of scrubber slurry composition and pH on the mercury species have been raised.

  14. Mercury distribution in the soil-plant-air system at the Wanshan mercury mining district in Guizhou, Southwest China.

    PubMed

    Wang, Jianxu; Feng, Xinbin; Anderson, Christopher W N; Zhu, Wei; Yin, Runsheng; Wang, Heng

    2011-12-01

    The level of mercury bioaccumulation in wild plants; the distribution of bioavailable Hg, elemental Hg, and total Hg in soil; and the concentration of total gaseous Hg (TGM) in ambient air was studied at three different mining sites (SiKeng [SK], WuKeng [WK], and GouXi [GX]) in the Wanshan mercury mining district of China. Results of the present study showed that the distribution of soil total Hg, elemental Hg, bioavailable Hg, and TGM varies across the three mining sites. Higher soil total Hg (29.4-1,972.3 mg/kg) and elemental Hg (19.03-443.8 mg/kg) concentrations were recorded for plots SK and WK than for plot GX. Bioavailable Hg was lower at plot SK and GX (SK, 3-12 ng/g; GX, 9-14 ng/g) than at plot WK (11-1,063 ng/g), although the TGM concentration in the ambient air was significantly higher for plot GX (52,723 ng/m(3) ) relative to WK (106 ng/m(3) ) and SK (43 ng/m(3)). Mercury in sampled herbage was elevated and ranged from 0.8 to 4.75 mg/kg (SK), from 2.17 to 34.38 mg/kg (WK), and from 47.45 to 136.5 mg/kg (GX). Many of the sampled plants are used as fodder or for medicinal purposes. High shoot Hg concentrations may therefore pose an unacceptable human health risk. Statistical analysis of the recorded data showed that the Hg concentration in plant shoots was positively correlated with TGM and that the Hg concentration in roots was positively correlated with the bioavailable Hg concentration in the soil. The bioaccumulation factor (BAF) in the present study was defined with reference to the concentration of bioavailable Hg in the soil (Hg([root]) /Hg([bioavail])). Three plant species, Macleaya cordata L., Achillea millefolium L., and Pteris vittata L., showed enhanced accumulation of Hg and therefore may have potential for use in the phytoremediation of soils of the Wanshan mining area. PMID:21935979

  15. Synchronized target subsystem for automated docking systems

    NASA Technical Reports Server (NTRS)

    Howard, Richard T. (Inventor); Book, Michael L. (Inventor); Bryan, Thomas C. (Inventor)

    2000-01-01

    A synchronized target subsystem for use in an automated docking or station keeping system for docking a chase vehicle with a target vehicle wherein the chase vehicle is provided with a video camera which provides adjacent frames each having a predetermined time duration. A light source mounted on the target vehicle flashes at a frequency which has a time duration which is a multiple of the duration time of the frames, the light being on for at least one frame duration and being off for the remainder of the cycle. An image processing unit is connected to the camera for receiving signals from the camera and subtracting one of the adjacent frames from the other to detect whether the light appears in one frame, both frames or neither frame. If the target light appears in both frames or neither frame, the image processing unit feeds a signal to a timing circuit to advance the video camera one frame. This process is continued until the target light appears in one frame and not in the other, at which time the process of advancing the video camera is stopped.

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

    SciTech Connect

    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

  17. Electrochemical properties of the lithium-mercury and lithium-indium-mercury systems at 25/sup 0/C

    SciTech Connect

    Korshunov, V.N.; Bacherikova, S.G.; Khlystrova, K.B.; Kreav, V.A.

    1986-03-01

    In order to locate the ''negative shift for indium relation'' by the dosed electrolysis method the emf was measured of amalgam concentration circuits. The results of potentiometric measurements are shown. The activity coefficients and the standard potentials of Li (Hg) at 25 C and the thickness of the solvation sphere of cations of a series of active M dissolved in mercury are presented. It is shown that the standard potential of M(Hg) is a parameter which reflects most completely the energy interactions of the components in an infinitely dilute amalgam. In the case of complex amalgams of the M-Me-Hg type the salting-out of the alkali metal takes place under the action of the third component introduced and it may be characterized by the value of the K/sub 0/ parameter which appears in the second equation presented.

  18. Mercury's Magnetosphere

    NASA Technical Reports Server (NTRS)

    Slavin, J. A.

    1999-01-01

    direct entry through the northern and southern cusps. Although Mariner 10 did not return plasma composition measurements, the Hermean magnetosphere should be ideal for measuring the manner and rate of solar wind plasma entry due to the lack of strong internal atmospheric sources. Finally, the solar wind conditions experienced by Mercury as it orbits the Sun at 0.31 to 0.47 AU are quite different from those typically encountered by the Earth. This may allow for new understanding of the external factors affecting the transfer of mass, momentum and energy from the solar wind to planetary magnetospheres. This article provides a brief overview of what is now known about Mercury's magnetosphere and why it is a priority target for future planetary missions.

  19. Tracking and Data System Support for the Mariner Venus/Mercury 1973 Project

    NASA Technical Reports Server (NTRS)

    Davis, E. K.; Traxler, M. R.

    1977-01-01

    The Tracking and Data System, which provided outstanding support to the Mariner Venus/Mercury 1973 project during the period from January 1970 through March 1975 are chronologically described. In the Tracking and Data System organizations, plans, processes, and technical configurations, which were developed and employed to facilitate achievement of mission objectives, are described. In the Deep Space Network position of the tracking and data system, a number of special actions were taken to greatly increase the scientific data return and to assist the project in coping with in-flight problems. The benefits of such actions were high; however, there was also a significant increase in risk as a function of the experimental equipment and procedures required.

  20. The effects of a stannous chloride-based water treatment system in a mercury contaminated stream

    DOE PAGESBeta

    Mathews, Teresa J.; Looney, Brian B.; Smith, John G.; Miller, Carrie L.; Peterson, Mark J.; Bryan, A. Lawrence; Southworth, George R.

    2015-06-09

    Remediation of mercury (Hg)-contaminated watersheds is often challenging because of the complex nature of Hg biogeochemistry. Stream ecosystems have been shown to be particularly susceptible to Hg contamination and bioaccumulation in fish. Decreasing total Hg loading to stream systems, however, has shown variable performance in decreasing Hg concentrations in fish tissues. In this study, we assess the impacts of an innovative treatment system in reducing releases of Hg to a small stream system in the southeastern United States. The treatment system, installed in 2007, removes Hg from water using tin (Sn) (II) chloride followed by air stripping. Mercury concentrations inmore » the receiving stream, Tims Branch, decreased from > 100 to ~10 ng/L in the four years following treatment, and Hg body burdens in redfin pickerel (Esox americanus) decreased by 70 % at the most contaminated site. Tin concentrations in water and fish increased significantly in the tributary leading to Tims Branch, but concentrations remain below levels of concern for human health or ecological risks. While other studies have shown that Sn may be environmentally methylated and methyltin can transfer its methyl group to Hg, results from our field studies and sediment incubation experiments suggest that the added Sn to the Tims Branch watershed is not contributing to MeHg production and bioaccumulation. The stannous chloride treatment system installed at Tims Branch was effective at removing Hg inputs and reducing Hg bioaccumulation in the stream with minimal impacts on the environment due to the increased Sn in the system.« less

  1. The effects of a stannous chloride-based remediation system in a mercury contaminated stream

    DOE PAGESBeta

    Mathews, Teresa J; Looney, Brian; BryanJr., Larry; Smith, John G; Miller, Carrie L; Peterson, Mark J

    2015-01-01

    Remediation of mercury (Hg)-contaminated watersheds is often challenging because of the complex nature of Hg biogeochemistry. Stream ecosystems have been shown to be particularly susceptible to Hg contamination and bioaccumulation in fish. Decreasing total Hg loading to stream systems, however, has shown variable performance in decreasing Hg concentrations in fish tissues. In this study, we assess the impacts of an innovative treatment system in reducing releases of Hg to a small stream system in the southeastern United States. The treatment system, installed in 2007, removes Hg from water using tin (Sn) (II) chloride followed by air stripping. Mercury concentrations inmore » the receiving stream, Tims Branch, decreased from > 100 to ~10 ng/L in the four years following treatment, and Hg body burdens in redfin pickerel (Esox americanus) decreased by 70 % at the most contaminated site. Tin concentrations in water and fish increased significantly in the tributary leading to Tims Branch, but concentrations remain below levels of concern for human health or ecological risks. While other studies have shown that Sn may be environmentally methylated and methyltin can transfer its methyl group to Hg, results from our field studies and sediment incubation experiments suggest that the added Sn to the Tims Branch watershed is not contributing to MeHg production and bioaccumulation. The stannous chloride treatment system installed at Tims Branch was effective at removing Hg inputs and reducing Hg bioaccumulation in the stream with minimal impacts on the environment due to the increased Sn in the system.« less

  2. Mercury Cavitation Phenomenon in Pulsed Spallation Neutron Sources

    SciTech Connect

    Futakawa, Masatoshi; Naoe, Takashi; Kawai, Masayoshi

    2008-06-24

    Innovative researches will be performed at Materials and Life Science Experimental Facility in J-PARC, in which a mercury target system will be installed as MW-class pulse spallation neutron sources. Proton beams will be injected into mercury target to induce the spallation reaction. At the moment the intense proton beam hits the target, pressure waves are generated in the mercury because of the abrupt heat deposition. The pressure waves interact with the target vessel leading to negative pressure that may cause cavitation along the vessel wall. Localized impacts by micro-jets and/or shock waves which are caused by cavitation bubble collapse impose pitting damage on the vessel wall. The pitting damage which degrades the structural integrity of target vessels is a crucial issue for high power mercury targets. Micro-gas-bubbles injection into mercury may be useful to mitigate the pressure wave and the pitting damage. The visualization of cavitation-bubble and gas-bubble collapse behaviors was carried out by using a high-speed video camera. The differences between them are recognized.

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

    SciTech Connect

    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.

  4. Targeted activation in deterministic and stochastic systems

    NASA Astrophysics Data System (ADS)

    Eisenhower, Bryan; Mezić, Igor

    2010-02-01

    Metastable escape is ubiquitous in many physical systems and is becoming a concern in engineering design as these designs (e.g., swarms of vehicles, coupled building energetics, nanoengineering, etc.) become more inspired by dynamics of biological, molecular and other natural systems. In light of this, we study a chain of coupled bistable oscillators which has two global conformations and we investigate how specialized or targeted disturbance is funneled in an inverse energy cascade and ultimately influences the transition process between the conformations. We derive a multiphase averaged approximation to these dynamics which illustrates the influence of actions in modal coordinates on the coarse behavior of this process. An activation condition that predicts how the disturbance influences the rate of transition is then derived. The prediction tools are derived for deterministic dynamics and we also present analogous behavior in the stochastic setting and show a divergence from Kramers activation behavior under targeted activation conditions.

  5. Fate and Transport of Mercury in a Watershed-Reservoir System Burned During the 2012 Hewlett Gulch Fire, Ft. Collins, Colorado

    NASA Astrophysics Data System (ADS)

    Webster, J.; Ryan, J. N.; Aiken, G.

    2014-12-01

    Deposition and accumulation of atmospheric mercury has led to the ubiquitous enrichment of this toxic metal in surficial soils around the planet. Remobilization of mercury into the atmosphere is generally associated with landscape disturbance, in particular wildfire, and is a significant component of annual global atmospheric mercury loading. In addition to atmospheric transport, wildfire may indirectly mobilize mercury into local surface waters through soil destabilization and increased watershed runoff. Transport of mercury into surface water and sulfate reducing environments may result in conversion of ionic mercury into methylmercury; a highly toxic and bioaccumulative form of the metal. Although increases in methylmercury production have been observed following wildfire, there is relatively little information regarding chemical and physical processes responsible for post-fire mercury mobilization and methylation. In this study, soils, fire debris, and reservoir sediments have been collected from a watershed-reservoir system burned in the 2012 Hewlett Gulch Fire, near Ft. Collins, Colorado. Subsequent coring of the reservoir sediment was conducted at multiple times to assess how early diagenesis of fire debris affects the fate of associated mercury. In addition to environmental sampling, laboratory microcosm experiments using fire debris are employed to assess the influence of redox driven processes on the fate of mercury in recently deposited reservoir sediments. Debris collected from the drainage and reservoir bottom are represented by charred and destabilized organic material which have total mercury concentrations of around 50 ng g-1, similar to native sediment; however, post-wildfire reservoir sediment have dramatically increased methylmercury concentrations. The influence of sulfur speciation, determined by X-ray absorption near-edge structure spectroscopy, on mercury binding is measured using competitive ligand exchange techniques and indicates enhanced

  6. Small Gas Bubble Experiment for Mitigation of Cavitation Damage and Pressure Waves in Short-pulse Mercury Spallation Targets

    SciTech Connect

    Wendel, Mark W; Felde, David K; Sangrey, Robert L; Abdou, Ashraf A; West, David L; Shea, Thomas J; Hasegawa, Shoichi; Kogawa, Hiroyuki; Naoe, Dr. Takashi; Farny, Dr. Caleb H.; Kaminsky, Andrew L

    2014-01-01

    Populations of small helium gas bubbles were introduced into a flowing mercury experiment test loop to evaluate mitigation of beam-pulse induced cavitation damage and pressure waves. The test loop was developed and thoroughly tested at the Spallation Neutron Source (SNS) prior to irradiations at the Los Alamos Neutron Science Center - Weapons Neutron Research Center (LANSCE-WNR) facility. Twelve candidate bubblers were evaluated over a range of mercury flow and gas injection rates by use of a novel optical measurement technique that accurately assessed the generated bubble size distributions. Final selection for irradiation testing included two variations of a swirl bubbler provided by Japan Proton Accelerator Research Complex (J-PARC) collaborators and one orifice bubbler developed at SNS. Bubble populations of interest consisted of sizes up to 150 m in radius with achieved gas void fractions in the 10^-5 to 10^-4 range. The nominal WNR beam pulse used for the experiment created energy deposition in the mercury comparable to SNS pulses operating at 2.5 MW. Nineteen test conditions were completed each with 100 pulses, including variations on mercury flow, gas injection and protons per pulse. The principal measure of cavitation damage mitigation was surface damage assessment on test specimens that were manually replaced for each test condition. Damage assessment was done after radiation decay and decontamination by optical and laser profiling microscopy with damaged area fraction and maximum pit depth being the more valued results. Damage was reduced by flow alone; the best mitigation from bubble injection was between half and a quarter that of flow alone. Other data collected included surface motion tracking by three laser Doppler vibrometers (LDV), loop wall dynamic strain, beam diagnostics for charge and beam profile assessment, embedded hydrophones and pressure sensors, and sound measurement by a suite of conventional and contact microphones.

  7. Mercury and Your Health

    MedlinePlus

    ... 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 ...

  8. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    C. Jean Bustard; Charles Lindsey; Paul Brignac

    2006-05-01

    This document provides a summary of the full-scale demonstration efforts involved in the project ''Field Test Program for Long-Term Operation of a COHPAC{reg_sign} System for Removing Mercury from Coal-Fired Flue Gas''. The project took place at Alabama Power's Plant Gaston Unit 3 and involved the injection of sorbent between an existing particulate collector (hot-side electrostatic precipitators) and a COHPAC{reg_sign} fabric filter (baghouse) downstream. Although the COHPAC{reg_sign} baghouse was designed originally for polishing the flue gas, when activated carbon injection was added, the test was actually evaluating the EPRI TOXECON{reg_sign} configuration. The results from the baseline tests with no carbon injection showed that the cleaning frequency in the COHPAC{reg_sign} unit was much higher than expected, and was above the target maximum cleaning frequency of 1.5 pulses/bag/hour (p/b/h), which was used during the Phase I test in 2001. There were times when the baghouse was cleaning continuously at 4.4 p/b/h. In the 2001 tests, there was virtually no mercury removal at baseline conditions. In this second round of tests, mercury removal varied between 0 and 90%, and was dependent on inlet mass loading. There was a much higher amount of ash exiting the electrostatic precipitators (ESP), creating an inlet loading greater than the design conditions for the COHPAC{reg_sign} baghouse. Tests were performed to try to determine the cause of the high ash loading. The LOI of the ash in the 2001 baseline tests was 11%, while the second baseline tests showed an LOI of 17.4%. The LOI is an indication of the carbon content in the ash, which can affect the native mercury uptake, and can also adversely affect the performance of ESPs, allowing more ash particles to escape the unit. To overcome this, an injection scheme was implemented that balanced the need to decrease carbon injection during times when inlet loading to the baghouse was high and increase carbon injection

  9. Modeling Mercury in Proteins.

    PubMed

    Parks, J M; Smith, J C

    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 nontoxic, other forms such as Hg(2+) 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 Hg(2+) can be methylated by certain bacteria and archaea to form methylmercury. Conversely, bacteria also demethylate methylmercury and reduce Hg(2+) 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 molecular picture and circumvent issues associated with toxicity. Here, we describe computational methods for investigating and characterizing how mercury binds to proteins, how inter- and intraprotein 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 confer mercury resistance in many bacteria. Lastly, we place work on mercury in proteins in the context of what is needed for a comprehensive multiscale model of environmental mercury cycling. PMID:27497164

  10. Prioritized System Science Targets for Heliophysics

    NASA Technical Reports Server (NTRS)

    Spann, James Frederick; Christensen, Andrew B.; SaintCyr, Orville Chris; Posner, Arik; Giles, Barbara L.

    2009-01-01

    Heliophysics is a discipline that investigates the science at work from the interface of Earth and space, to the core of the Sun, and to the outer edge of our solar system. This solar-interplanetary-planetary system is vast and inherently coupled on many spatial, temporal and energy scales. The Sun's explosive energy output creates complicated field and plasma structures that when coupled with our terrestrial magnetized space, generates an extraordinary complex environment that has practical implications for humanity as we are becoming increasingly dependent on space-based assets. This immense volume of our cosmic neighborhood is the domain of heliophysics. Understanding this domain and the dominant mechanisms that control the transfer of mass and energy requires a system approach that addresses all aspects and regions of the system. The 2009 NASA Heliophysics Roadmap presents a science-focused strategic approach to advance the goal of heliophysics: why does the Sun vary; how do the Earth and heliosphere respond; and what are the impacts on humanity? This talk will present the top 6 prioritized science targets to understand the coupled heliophysics system as presented in the 2009 NASA Heliophysics Roadmap. An exposition of each science target and how it addresses outstanding questions in heliophysics will be discussed.

  11. Future System Science Mission Targets for Heliophysics

    NASA Technical Reports Server (NTRS)

    Spann, James; Christensen, Andrew B.; SaintCyr, O. C.; Giles, Barbara I.; Posner, Arik

    2009-01-01

    Heliophysics is a discipline that investigates the science at work from the interface of Earth and space, to the core of the Sun, and to the outer edge of our solar system. This solar-interplanetary-planetary system is vast and inherently coupled on many spatial, temporal and energy scales. The Sun's explosive energy output creates complicated field and plasma structures that when coupled without terrestrial magnetized space, generates an extraordinary complex environment that has practical implications for humanity as we are becoming increasingly dependent on space-based assets. The immense volume of our cosmic neighborhood is the domain of heliophysics. Understanding this domain and the dominant mechanisms that control the transfer of mass and energy requires a system approach that addresses all aspects and regions of the system. The 2009 NASA Heliophysics Roadmap presents a science-focused strategic approach to advance the goal of heliophysics: why does the Sun vary; how do the Earth and heliosphere respond; and what are the impacts on humanity? This talk will present the top 6 prioritized science targets to understand the coupled heliophysics system as presented in the 2009 NASA Heliophysics Roadmap. An exposition of each science target and how it addresses outstanding questions in heliophysics will be discussed.

  12. MODELING MERCURY DYNAMICS IN STREAM SYSTEMS WITH WASP7: CHARACTERIZING PROCESSES CONTROLLING SHORT AND LONG TERM RESPONSE

    EPA Science Inventory

    Mercury transport through stream ecosystems is driven by a complicated set of transport and transformation reactions operating on a variety of scales in the atmosphere, landscape, surface water, and biota. Riverine systems typically have short residence times and can experience l...

  13. MESSENGER at Mercury: Early Orbital Operations

    NASA Technical Reports Server (NTRS)

    McNutt, Ralph L., Jr; Solomon, Sean C.; Bedini, Peter D.; Anderson, Brian J.; Blewett, David T.; Evans, Larry G.; Gold, Robert E.; Krimigis, Stamatios M.; Murchie, Scott L.; Nittler, Larry R.; Philips, Roger J.; Prockter, Louise M.; Slavin, James A.; Zuber, M. T.; Finnegan, Eric J.; Grant, David G.

    2013-01-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, launched in August 2004 under NASA's Discovery Program, was inserted into orbit about the planet Mercury in March 2011. MESSENGER's three flybys of Mercury in 2008-2009 marked the first spacecraft visits to the innermost planet since the Mariner 10 flybys in 1974-1975. The unprecedented orbital operations are yielding new insights into the nature and evolution of Mercury. The scientific questions that frame the MESSENGER mission led to the mission measurement objectives to be achieved by the seven payload instruments and the radio science experiment. Interweaving the full set of required orbital observations in a manner that maximizes the opportunity to satisfy all mission objectives and yet meet stringent spacecraft pointing and thermal constraints was a complex optimization problem that was solved with a software tool that simulates science observations and tracks progress toward meeting each objective. The final orbital observation plan, the outcome of that optimization process, meets all mission objectives. MESSENGER's Mercury Dual Imaging System is acquiring a global monochromatic image mosaic at better than 90% coverage and at least 250 m average resolution, a global color image mosaic at better than 90% coverage and at least 1 km average resolution, and global stereo imaging at better than 80% coverage and at least 250 m average resolution. Higher-resolution images are also being acquired of targeted areas. The elemental remote sensing instruments, including the Gamma-Ray and Neutron Spectrometer and the X-Ray Spectrometer, are being operated nearly continuously and will establish the average surface abundances of most major elements. The Visible and Infrared Spectrograph channel of MESSENGER's Mercury Atmospheric and Surface Composition Spectrometer is acquiring a global map of spectral reflectance from 300 to 1450 nm wavelength at a range of incidence and emission

  14. MESSENGER at Mercury: Early Orbital Operations

    NASA Technical Reports Server (NTRS)

    McNutt, Ralph L., Jr.; Solomon, Sean C.; Bedini, Peter D.; Anderson, Brian J.; Blewett, David T.; Evans, Larry G.; Gold, Robert E.; Krimigis, Stamatios M.; Murchie, Scott L.; Nittler, Larry R.; Slavin, James A.

    2012-01-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, launched in August 2004 under NASA's Discovery Program, was inserted into orbit about the planet Mercury in March 2011. MESSENGER's three flybys of Mercury in 2008-2009 marked the first spacecraft visits to the innermost planet since the Mariner 10 flybys in 1974-1975. The unprecedented orbital operations are yielding new insights into the nature and evolution of Mercury. The scientific questions that frame the MESSENGER mission led to the mission measurement objectives to be achieved by the seven payload instruments and the radio science experiment. Interweaving the full set of required orbital observations in a manner that maximizes the opportunity to satisfy all mission objectives and yet meet stringent spacecraft pointing and thermal constraints was a complex optimization problem that was solved with a software tool that simulates science observations and tracks progress toward meeting each objective. The final orbital observation plan, the outcome of that optimization process, meets all mission objectives. MESSENGER's Mercury Dual Imaging System is acquiring a global monochromatic image mosaic at better than 90%coverage and at least 250 m average resolution, a global color image mosaic at better than 90%coverage and at least 1 km average resolution, and global stereo imaging at better than 80%coverage and at least 250 m average resolution. Higher-resolution images are also being acquired of targeted areas. The elemental remote sensing instruments, including the Gamma-Ray and Neutron Spectrometer and the X-Ray Spectrometer, are being operated nearly continuously and will establish the average surface abundances of most major elements. The Visible and Infrared Spectrograph channel of MESSENGER's Mercury Atmospheric and Surface Composition Spectrometer is acquiring a global map of spectral reflectance from 300 to 1450 nm wavelength at a range of incidence and emission angles

  15. MESSENGER at Mercury: Early orbital operations

    NASA Astrophysics Data System (ADS)

    McNutt, Ralph L.; Solomon, Sean C.; Bedini, Peter D.; Anderson, Brian J.; Blewett, David T.; Evans, Larry G.; Gold, Robert E.; Krimigis, Stamatios M.; Murchie, Scott L.; Nittler, Larry R.; Phillips, Roger J.; Prockter, Louise M.; Slavin, James A.; Zuber, Maria T.; Finnegan, Eric J.; Grant, David G.; MESSENGER Team

    2014-01-01

    The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, launched in August 2004 under NASA's Discovery Program, was inserted into orbit about the planet Mercury in March 2011. MESSENGER's three flybys of Mercury in 2008-2009 marked the first spacecraft visits to the innermost planet since the Mariner 10 flybys in 1974-1975. The unprecedented orbital operations are yielding new insights into the nature and evolution of Mercury. The scientific questions that frame the MESSENGER mission led to the mission measurement objectives to be achieved by the seven payload instruments and the radio science experiment. Interweaving the full set of required orbital observations in a manner that maximizes the opportunity to satisfy all mission objectives and yet meet stringent spacecraft pointing and thermal constraints was a complex optimization problem that was solved with a software tool that simulates science observations and tracks progress toward meeting each objective. The final orbital observation plan, the outcome of that optimization process, meets all mission objectives. MESSENGER's Mercury Dual Imaging System is acquiring a global monochromatic image mosaic at better than 90% coverage and at least 250 m average resolution, a global color image mosaic at better than 90% coverage and at least 1 km average resolution, and global stereo imaging at better than 80% coverage and at least 250 m average resolution. Higher-resolution images are also being acquired of targeted areas. The elemental remote sensing instruments, including the Gamma-Ray and Neutron Spectrometer and the X-Ray Spectrometer, are being operated nearly continuously and will establish the average surface abundances of most major elements. The Visible and Infrared Spectrograph channel of MESSENGER's Mercury Atmospheric and Surface Composition Spectrometer is acquiring a global map of spectral reflectance from 300 to 1450 nm wavelength at a range of incidence and emission

  16. Environmental management system objectives & targets results summary :

    SciTech Connect

    Vetter, Douglas Walter

    2014-04-01

    Sandia National Laboratories/New Mexicos (SNL/NM) Environmental Management System is the integrated approach for members of the workforce to identify and manage environmental risks. Each Fiscal Year (FY) SNL/NM performs an analysis to identify environmental aspects, and the environmental programs associated with them are charged with the task of routinely monitoring and measuring the objectives and targets that are established to mitigate potential impacts of SNL/NMs operations on the environment. An annual summary of the results achieved towards meeting established Sandia Corporation and SNL/NM Site-specific objectives and targets provides a connection to, and rational for, annually revised environmental aspects. The purpose of this document is to summarize the results achieved and documented in FY2013.

  17. Achromatic illumination system for small targets

    DOEpatents

    Sigler, Robert D.

    1979-01-01

    A pair of light beams is directed to provide illumination that is substantially uniform from all directions on a small target by a system comprising a pair of corrector windows, a pair of planar reflecting surfaces, a pair of paraboloidal mirrors and a reflecting mirror cavity. The components are arranged so that each of the beams passes through a corrector and is reflected from the planar surface to the paraboloidal mirror, from which it is focused through a hole in the planar surface to the interior of the cavity. The surface of the interior portion of the cavity is shaped to reflect the focused beam three times before the focused reflected beam strikes the target.

  18. Mercury pollution and childhood in Amazon riverside villages.

    PubMed

    Pinheiro, M C N; Crespo-López, M E; Vieira, J L F; Oikawa, T; Guimarães, G A; Araújo, C C; Amoras, W W; Ribeiro, D R; Herculano, A M; do Nascimento, J L M; Silveira, L C L

    2007-01-01

    Mercury is a hazardous metal responsible for environmental contamination and human intoxication. Methylmercury, a very toxic organic compound, bio-accumulates through food chain, and is responsible for chronic mercury exposure of riverside Amazonian communities with a diet rich in fish. Uncertainties about the reference exposure dose that could have damaging consequences for nervous system development makes necessary the biomonitoring of these Amazonian populations, especially children. In this work, a comparative study was performed in exposed and non-exposed children living in the Amazon. A total of 168 children were analyzed to find possible correlations between gender, age, location, and hair mercury content. For each location, no statistically significant differences (P<0.05) were detected for gender and age versus mercury content. However, mean mercury levels in hair samples may indicate a tendency of boys to average higher hair concentrations. Also, in the community with highest levels of mercury, the limit of 10 micro g/g of mercury was surpassed by 65% of 2-6 years and 50% of 7-12 years children but only by 27% of 0-1 year babies, pointing to a lower bioaccumulation and/or the existence of a protection mechanism in babies. Log normal distributions of mercury concentrations for each location showed that children from populations under influence of gold mining activity contain the highest mercury levels in hair samples, though this intoxication may have decreased when compared to previous studies. Knowledge originated by this monitoring will better assist in the development of prevention strategies and government actions targeting the mercury contamination of Amazonian environment. PMID:16930706

  19. Planet Mercury

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Mariner 10's first image of Mercury acquired on March 24, 1974. During its flight, Mariner 10's trajectory brought it behind the lighted hemisphere of Mercury, where this image was taken, in order to acquire important measurements with other instruments.

    This picture was acquired from a distance of 3,340,000 miles (5,380,000 km) from the surface of Mercury. The diameter of Mercury (3,031 miles; 4,878 km) is about 1/3 that of Earth.

    Images of Mercury were acquired in two steps, an inbound leg (images acquired before passing into Mercury's shadow) and an outbound leg (after exiting from Mercury's shadow). More than 2300 useful images of Mercury were taken, both moderate resolution (3-20 km/pixel) color and high resolution (better than 1 km/pixel) black and white coverage.

  20. Planet Mercury

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Mariner 10's first image of Mercury acquired on March 24, 1974. During its flight, Mariner 10's trajectory brought it behind the lighted hemisphere of Mercury, where this image was taken, in order to acquire important measurements with other instruments. This picture was acquired from a distance of 3,340,000 miles (5,380,000 km) from the surface of Mercury. The diameter of Mercury (3,031 miles; 4,878 km) is about 1/3 that of Earth. Images of Mercury were acquired in two steps, an inbound leg (images acquired before passing into Mercury's shadow) and an outbound leg (after exiting from Mercury's shadow). More than 2300 useful images of Mercury were taken, both moderate resolution (3-20 km/pixel) color and high resolution (better than 1 km/pixel) black and white coverage.

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

    SciTech Connect

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

    2013-07-01

    below a target industrial groundwater concentration beneath the source and would not influence concentrations in surface water at Station 17. This analysis addressed only shallow concentrations in soil and the shallow groundwater flow path in soil and unconsolidated sediments to UEFPC. Other mercury sources may occur in bedrock and transport though bedrock to UEFPC may contribute to the mercury flux at Station 17. Generally mercury in the source areas adjacent to the stream and in sediment that is eroding can contribute to the flux of mercury in surface water. Because colloidally adsorbed mercury can be transported in surface water, actions that trap colloids and or hydrologically isolate surface water runoff from source areas would reduce the flux of mercury in surface water. Mercury in soil is highly adsorbed and transport in the groundwater system is very limited under porous media conditions. (authors)

  2. Impact of Climate Change on Mercury Transport along the Carson River-Lahontan Reservoir System

    NASA Astrophysics Data System (ADS)

    Flickinger, A.; Carroll, R. W. H.; Warwick, J. J.; Schumer, R.

    2014-12-01

    Historic mining practices have left the Carson River and Lahontan Reservoir (CRLR) system contaminated with high levels of mercury (Hg). Hg levels in Lahontan Reservoir planktivorous and predatory fish exceed federal consumption limits. Inputs of Hg to the system are mainly a result of erosion during high flow and diffusion from sediment during low flow, and the relationships between streamflow and both mercury transport and bioaccumulation are non-linear. The United States Bureau of Reclamation has produced future streamflow estimates for 2000-2099 using 112 CMIP3 climate projections and the Variable Infiltration Capacity (VIC) model. VIC results suggest that the hydrology of the system is likely to experience higher frequencies of both high and low extreme flows, and the monthly averages of future flows are expected to be higher in the winter and lower in the summer compared to observed flows. VIC daily streamflow estimates are biased-corrected using an empirical cumulative distribution function to match observed data over the historic period of 1950-1999. Future reservoir stage and outflows are modeled assuming reservoir operations are a function of river/canal inflows, previous reservoir stage and downstream agricultural demands. VIC and reservoir flows drive the CRLR Hg transport model (RIVMOD, WASP5, and MERC4). Daily output for both total and dissolved inorganic Hg and methylmercury (MeHg) are averaged at the decadal timescale to assess changes and uncertainty in predicted spatial and temporal Hg species water column concentrations as a function of altered hydrology with respect to changing climate. Future research will use CRLR output in a bioenergetics and Hg mass balance model for Sacramento blackfish (Orthodon microlepidotus), a filter feeding cyprinid found in Lahontan Reservoir. These future simulations will help to assess possible changes in ecosystem health with respect to hydrologic conditions and associated changes to Hg transport.

  3. MESSENGER: Exploring Mercury's Magnetosphere

    NASA Technical Reports Server (NTRS)

    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.

  4. Improved chronic fatigue symptoms after removal of mercury in patient with increased mercury concentration in hair toxic mineral assay: a case.

    PubMed

    Shin, Sae-Ron; Han, A-Lum

    2012-09-01

    Clinical manifestations of chronic exposure to organic mercury usually have a gradual onset. As the primary target is the nervous system, chronic mercury exposure can cause symptoms such as fatigue, weakness, headache, and poor recall and concentration. In severe cases chronic exposure leads to intellectual deterioration and neurologic abnormality. Recent outbreaks of bovine spongiform encephalopathy and pathogenic avian influenza have increased fish consumption in Korea. Methyl-mercury, a type of organic mercury, is present in higher than normal ranges in the general Korean population. When we examine a patient with chronic fatigue, we assess his/her methyl-mercury concentrations in the body if environmental exposure such as excessive fish consumption is suspected. In the current case, we learned the patient had consumed many slices of raw tuna and was initially diagnosed with chronic fatigue syndrome. Therefore, we suspected that he was exposured to methyl-mercury and that the mercury concentration in his hair would be below the poisoning level identified by World Health Organization but above the normal range according to hair toxic mineral assay. Our patient's toxic chronic fatigue symptoms improved after he was given mercury removal therapy, indicating that he was correctly diagnosed with chronic exposure to organic mercury. PMID:23115707

  5. Non-ideal liquidus curve in the Fe-S system and Mercury's snowing core

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Li, Jie; Hauck, Steven A.

    2008-04-01

    We conducted multi-anvil experiments to investigate the melting behavior of the iron-sulfur system at moderate pressures. Our data reveal a positive departure from ideal solution behavior at 14 GPa, as indicated by the presence of two inflection points on the liquidus curve of iron-rich compositions. In contrast, the shape of the liquidus curve at 10 GPa is consistent with nearly ideal mixing between end-member components. Combined with existing data at lower pressures and above 20 GPa, our results suggest a negative liquidus temperature gradient under conditions found at shallow depths in Mercury's core. At the present time, the core is most likely precipitating solid iron in the form of snow, at a single depth or in two distinct zones. Formation and segregation of iron snow would alter the thermal and chemical state of the core and influence the origin and surface expression of the planet's magnetic field.>

  6. Mercury and Beyond: Diode-Pumped Solid-State Lasers for Inertial Fusion Energy

    SciTech Connect

    Bibeau, C.; Beach, R.J.; Bayramian, A.; Chanteloup, J.C.; Ebbers, C.A.; Emanuel, M.A.; Orth, C.D.; Rothenberg, J.E.; Schaffers, K.I.; Skidmore, J.A.; Sutton, S.B.; Zapata, L.E.; Payne, S.A.; Powell, H.T.

    1999-10-19

    We have begun building the ''Mercury'' laser system as the first in a series of new generation diode-pumped solid-state lasers for inertial fusion research. Mercury will integrate three key technologies: diodes, crystals, and gas cooling, within a unique laser architecture that is scalable to kilojoule energy levels for fusion energy applications. The primary performance goals include 10% electrical efficiencies at 10 Hz and 100 J with a 2-10 ns pulse length at 1.047 pm wavelength. When completed, Mercury will allow rep-rated target experiments with multiple target chambers for high energy density physics research.

  7. IHAVS NITE Hawk SC targeting FLIR system

    NASA Astrophysics Data System (ADS)

    McNamara, Bob

    1996-06-01

    Loral Aeronutronic is supporting the IHAVS project by integrating Navy-furnished NITE Hawk Targeting FLIR Pod (AN/AAS-38B) Weapons Replaceable Assemblies (WRAs) with Loral-furnished aft section and interface module WRAs for flight testing on a TAV-8B. Loral developed an aft section WRA without the conformal fairing required for installation on an F/A-18 and incorporated a self-cooling system. WRAs from the AN/AAS-38B pod are integrated in this aft section to provide a pod which is functionally the same as the F/A-18 system yet can be installed on any aircraft. Loral calls this derivative of the F/A-18 NITE Hawk pod the NITE Hawk Self-Cooled (SC) pod. The NITE Hawk SC has also has also been flight demonstrated on the F-15, F-16 and F-14 platforms and is the baseline laser targeting system on the Spanish Air Force's EF-2000 aircraft. The Loral-developed interface module WRA provides the capability to translate messages from any aircraft mission computer into the particular format design for the F/A-18 controller processor WRA. This maintains maximum commonality to the AN/AAS-38B WRAs. The interface module provides for signal processing of the FLIR video and includes the capability to electronically zoom, freeze, and format the video output into any standard required by the aircraft.

  8. Developments of a Targeted Ensemble Prediction System

    NASA Astrophysics Data System (ADS)

    Hersbach, H.; Mureau, R.; Opsteegh, J. D.; Barkmeijer, J.

    2003-04-01

    Based on results presented in a previous paper, an Ensemble Prediction System, especially designed for the short-range to early-medium range for the European domain (TEPS), was further developed. Between 1 January 1999 and 27 February 2000 this system was run for two cases per week. Results were compared to the ensemble prediction system (EPS) that was operational at the European Centre for Medium-Range Weather Forecasts at the time. The focus was on weather parameters. Several configurations were tested. Besides perturbations that optimize total error growth for the European domain at 48 h, perturbations relevant for shorter forecast times were included as well. Firstly, in accordance with EPS, evolved northern hemispheric singular vectors (ETEPS) and secondly, targeted singular vectors with an optimization time of 12 h (STEPS) were added. Compared to EPS, ensemble spread was increased in the short range, having a beneficial effect on statistical properties such as reliability and the frequency of outliers. Spread-skill correlations improved as well. Best performance was found for the STEPS configuration. The impact on Brier scores, relative operating characteristic curves and cost-loss analyses was less clear. From the singular vector point of view, the positive impact of using targeted perturbations is evident. However, after integration (STEPS or ETEPS), it was difficult to find synoptic cases in which this clear impact is still present.

  9. ATMOSPHERIC MERCURY SIMULATION USING THE CMAQ MODEL: FORMULATION DESCRIPTION AND ANALYSIS OF WET DEPOSITION RESULTS

    EPA Science Inventory

    The Community Multiscale Air Quality (CMAQ) modeling system has recently been adapted to simulate the emission, transport, transformation and deposition of atmospheric mercury in three distinct forms; elemental mercury gas, reactive gaseous mercury, and particulate mercury. Emis...

  10. Modeling unmanned system collaborative target engagement

    NASA Astrophysics Data System (ADS)

    Jaenisch, Holger M.; Handley, James W.; Hicklen, Michael L.

    2007-04-01

    This paper describes a novel algorithm for collaborative target engagement by unmanned systems (UMS) resulting in emergent behavior. We demonstrate UMS collaborative engagement using a simulation testbed model of a road, convoy vehicles traveling along the road, a squadron of unmanned aerial vehicles (UAVs), and multiple unmanned ground vehicles (UGVs) which are set to detonate when within close proximity to a convoy vehicle. No explicit artificial intelligence or swarming algorithms were used. Collision avoidance was an intrinsic phenomena. All entities acted independently throughout the simulation, but were given similar local instructions for possible courses of action (COAs) depending on current situations. Our algorithm and results are summarized in this paper.

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

    SciTech Connect

    Liang, Youxin; Sun, Rongkun; Sun, Yu; Chen, Ziqiang; Li, Linhong )

    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.

  12. IMPACT OF ELIMINATING MERCURY REMOVAL PRETREATMENT ON THE PERFORMANCE OF A HIGH LEVEL RADIOACTIVE WASTE MELTER OFFGAS SYSTEM

    SciTech Connect

    Zamecnik, J; Alexander Choi, A

    2009-03-17

    The Defense Waste Processing Facility at the Savannah River Site processes high-level radioactive waste from the processing of nuclear materials that contains dissolved and precipitated metals and radionuclides. Vitrification of this waste into borosilicate glass for ultimate disposal at a geologic repository involves chemically modifying the waste to make it compatible with the glass melter system. Pretreatment steps include removal of excess aluminum by dissolution and washing, and processing with formic and nitric acids to: (1) adjust the reduction-oxidation (redox) potential in the glass melter to reduce radionuclide volatility and improve melt rate; (2) adjust feed rheology; and (3) reduce by steam stripping the amount of mercury that must be processed in the melter. Elimination of formic acid pretreatment has been proposed to eliminate the production of hydrogen in the pretreatment systems; alternative reductants would be used to control redox. However, elimination of formic acid would result in significantly more mercury in the melter feed; the current specification is no more than 0.45 wt%, while the maximum expected prior to pretreatment is about 2.5 wt%. An engineering study has been undertaken to estimate the effects of eliminating mercury removal on the melter offgas system performance. A homogeneous gas-phase oxidation model and an aqueous phase model were developed to study the speciation of mercury in the DWPF melter offgas system. The model was calibrated against available experimental data and then applied to DWPF conditions. The gas-phase model predicted the Hg{sub 2}{sup 2-}/Hg{sup 2+} ratio accurately, but some un-oxidized Hg{sup 0} remained. The aqueous model, with the addition of less than 1 mM Cl{sub 2} showed that this remaining Hg{sup 0} would be oxidized such that the final Hg{sub 2}{sup 2+}/Hg{sup 2+} ratios matched the experimental data. The results of applying the model to DWPF show that due to excessive shortage of chloride, only 6% of

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

    NASA Astrophysics Data System (ADS)

    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

  14. Effect of abiotic factors on the mercury reduction process by humic acids in aqueous systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mercury (Hg) in the environment can have serious toxic effects on a variety of living organisms, and is a pollutant of concern worldwide. The reduction of mercury from the toxic Hg2+ form to Hg0 is especially important. One pathway for this reduction to occur is through an abiotic process with humic...

  15. Mercury content of shrimp (Penaeus vannamei) reared in a wastewater-seawater aquacultural system

    SciTech Connect

    Landau, M.; Pierce, R.

    1986-10-01

    Penaeus vannamei were reared in two ponds, one receiving 10% wastewater in seawater and no feed, and the other receiving only seawater and a prepared commercial feed. The pond receiving the wastewater had significantly more mercury in the sediment, yet shrimp in this pond did not accumulate significant amounts of the mercury in their edible tissue.

  16. Planned flight test of a mercury ion auxiliary propulsion system. 1: Objectives, systems descriptions, and mission operations

    NASA Technical Reports Server (NTRS)

    Power, J. C.

    1978-01-01

    A planned flight test of an 8 cm diameter, electron-bombardment mercury ion thruster system is described. The primary objective of the test is to flight qualify the 5 mN (1 mlb.) thruster system for auxiliary propulsion applications. A seven year north-south stationkeeping mission was selected as the basis for the flight test operating profile. The flight test, which will employ two thruster systems, will also generate thruster system space performance data, measure thruster-spacecraft interactions, and demonstrate thruster operation in a number of operating modes. The flight test is designated as SAMSO-601 and will be flown aboard the shuttle-launched Air Force space test program P80-1 satellite in 1981. The spacecraft will be 3- axis stabilized in its final 740 km circular orbit, which will have an inclination of approximately greater than 73 degrees. The spacecraft design lifetime is three years.

  17. Planned flight test of a mercury ion auxiliary propulsion system. I - Objectives, systems descriptions, and mission operations

    NASA Technical Reports Server (NTRS)

    Power, J. L.

    1978-01-01

    A planned flight test of an 8-cm diameter, electron-bombardment mercury ion thruster system is described. The primary objective of the test is to flight qualify the 5 mN thruster system for auxiliary propulsion applications. A seven year north-south stationkeeping mission was selected as the basis for the flight test operating profile. The flight test, which will employ two thruster systems, will also generate thruster system space performance data, measure thruster-spacecraft interactions, and demonstrate thruster operation in a number of operating modes. The flight test is designated as SAMSO-601 and will be flown aboard the Shuttle-launched Air Force Space Test Program P80-1 satellite in 1981. The spacecraft will be 3-axis stabilized in its final 740 km circular orbit, which will have an inclination of at least 73 degrees. The spacecraft design lifetime is three years.

  18. Targeted therapies in systemic lupus erythematosus.

    PubMed

    Grech, P; Khamashta, Ma

    2013-09-01

    Systemic lupus erythematosus (SLE) is a chronic, multisystem disorder characterised by loss of tolerance to endogenous nuclear antigens and autoantibody formation. Recent insight into the immunopathogenesis of lupus has provided the foundation for a novel class of agents which target specific, dysregulated components of the immune system. Efforts have focused predominantly on B-cell depleting therapies, of which belimumab was the first to demonstrate success in phase III studies and thus receive marketing authorisation. Off-label prescribing of rituximab in refractory cases is common and supported by uncontrolled studies, which suggest a favourable risk:benefit profile. However, two placebo-controlled trials failed to show benefit, possibly because of inappropriate patient selection and other aspects of trial methodology. Inhibition of dysregulated co-stimulatory signals and cytokines are other therapeutic strategies currently under investigation. Some candidate drugs failed to meet primary endpoints in early-phase clinical trials, yet demonstrated clinical benefit when alternative assessment criteria were applied or specific patient sub-groups analysed. Well-designed studies of greater size and duration are needed to clarify the therapeutic utility of these agents. Future immunomodulatory strategies targeting interferon-alpha, T cells, oxidative stress and epigenetic abnormalities may reduce multisystem disease activity and prolong survival in this complex and heterogeneic disease. PMID:23963429

  19. Impact of Wildfire on Levels of Mercury in Forested Watershed Systems - Voyageurs National Park, Minnesota

    USGS Publications Warehouse

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

    2009-01-01

    Atmospheric deposition of mercury to remote lakes in mid-continental and eastern North America has increased approximately threefold since the mid-1800s (Swain and others, 1992; Fitzgerald and others, 1998; Engstrom and others, 2007). As a result, concerns for human and wildlife health related to mercury contamination have become widespread. Despite an apparent recent decline in atmospheric deposition of mercury in many areas of the Upper Midwest (Engstrom and Swain, 1997; Engstrom and others, 2007), lakes in which fish contain levels of mercury deemed unacceptable for human consumption and possibly unacceptable for fish-consuming wildlife are being detected with increasing frequency. In northern Minnesota, Voyageurs National Park (VNP) (fig. 1) protects a series of southern boreal lakes and wetlands situated on bedrock of the Precambrian Canadian Shield. Mercury contamination has become a significant resource issue within VNP as high concentrations of mercury in loons, bald eagle eaglets, grebes, northern pike, and other species of wildlife and fish have been found. The two most mercury-contaminated lakes in Minnesota, measured as methylmercury in northern pike (Esox lucius), are in VNP. Recent multidisciplinary U.S. Geological Survey (USGS) research demonstrated that the bulk of the mercury in lake waters, soils, and fish in VNP results from atmospheric deposition (Wiener and others, 2006). The study by Wiener and others (2006) showed that the spatial distribution of mercury in watershed soils, lake waters, and age-1 yellow perch (Perca flavescens) within the Park was highly variable. The majority of factors correlated for this earlier study suggested that mercury concentrations in lake waters and age-1 yellow perch reflected the influence of ecosystem processes that affected within-lake microbial production and abundance of methylmercury (Wiener and others, 2006), while the distribution of mercury in watershed soils seemed to be partially dependent on forest

  20. The effects of a stannous chloride-based water treatment system in a mercury contaminated stream.

    PubMed

    Mathews, Teresa J; Looney, Brian B; Bryan, A Lawrence; Smith, John G; Miller, Carrie L; Southworth, George R; Peterson, Mark J

    2015-11-01

    We assessed the impacts of an innovative Hg water treatment system on a small, industrially-contaminated stream in the southeastern United States. The treatment system, installed in 2007, removes Hg from wastewater using tin (Sn) (II) chloride followed by air stripping. Mercury concentrations in the receiving stream, Tims Branch, decreased from >100 to ∼10 ng/L in the four years following treatment, and Hg body burdens in redfin pickerel (Esox americanus) decreased by 70% at the most contaminated site. Tin concentrations in water and fish increased significantly in the tributary leading to Tims Branch, but concentrations remain below levels of concern for human health or ecological risks. While other studies have shown that Sn may be environmentally methylated and methyltin can transfer its methyl group to Hg, results from our field studies and sediment incubation experiments suggest that the added Sn to the Tims Branch watershed is not contributing to methylmercury (MeHg) production or bioaccumulation in this system. The stannous chloride treatment system installed at Tims Branch was effective at removing Hg inputs and reducing Hg bioaccumulation in the stream, but future studies are needed to assess longer term impacts of Sn on the environment. PMID:26070084

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

    SciTech Connect

    Baatrup, E.; Doving, K.B. )

    1990-12-01

    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 (CH{sub 3}HgCl, 99 micrograms Hg/g) for 4 weeks. Other groups of fish were exposed to dissolved mercuric chloride (HgCl{sub 2}, 270 micrograms Hg/liter) for 2, 6, and 12 hr, respectively. In both series of experiments, the radioisotope {sup 203}Hg was included in order to determine the accumulation of mercury in the olfactory system. Gamma-spectrometry showed that both mercury compounds accumulated in the olfactory rosettes and their nerves. Tissue sections from the rosettes and olfactory nerves were subjected to autometallographic silver enhancement, thereby rendering mercury deposits visible for light and electron microscopy. Microscopic analysis demonstrated an intense and comprehensive Hg deposition 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 the receptor cells, while those produced by HgCl{sub 2} exposure were situated mainly along the borders of neighboring cells. The present findings that organic and inorganic mercury compounds were deposited in the olfactory system along its whole length, from the receptor cell apices to the brain, support the electrophysiological results presented elsewhere.

  2. Design of a condenser-boiler for a binary mercury-organic Rankine cycle solar dynamic space power system

    NASA Astrophysics Data System (ADS)

    Cotton, Randy M.

    1987-05-01

    A theoretical design was performed for the condenser/boiler of a space-based solar dynamic power system. The base system is a binary Rankine cycle with mercury and toluene as the working fluids. System output is 75 KWe with a combined efficiency of 41.1%. Design goals were to develop the most reliable, mass efficient unit possible for delivery to a space station. The design sized the unit based on toluene properties and used a computer generated heat balance to thermodynamically match the two fluids. Molybdenum was chosen as the material due to mass effectiveness in heat transfer, strength, and resistance to mercury corrosion. The unit transferred 137.46 kilowatts of thermal power and can operate at varying mass flow rates. Effectiveness in heat transfer is 0.96 and mass performance is 0.016 kg/KWth transferred. The design depends on using only existing technologies and the results call for no new developments.

  3. Development of a particulate mass measurement system for tracing pollution sources using atmospheric mercury concentrations and lead isotopes

    NASA Astrophysics Data System (ADS)

    Pierce, A.; Gustin, M. S.; Christensen, J. N.

    2015-12-01

    The Teledyne Advanced Pollution Instrumentation Model 602 BetaPlus (TAPI) particulate measurement system is a unique platform for non-destructive analysis of PM2.5 mass concentration, and destructive analyses of particulate bound mercury (PBM), perhaps gaseous oxidized mercury (GOM), and lead isotopes. Samples were collected at a flow rate of 16.7 Lpm for 24 hours on 47 mm diameter cation exchange membranes (CEM) for mercury (Hg) and Teflon membranes for lead isotopes. We compared total mercury collected on CEM filters from the TAPI to that collected with the UNR active Hg membrane system and a Tekran 2537/1130/1135 system for gaseous Hg at a highway-impacted site (elev. 1370 m) from December 2013 to November 2015. The TAPI and UNR active system were also compared at a high elevation site (elev. 2515 m) adjacent to the highway-impacted site from December 2013 to October 2014. Data collection using the TAPI and UNR active system started in spring and summer of 2015 at Great Basin National Park (GBNP) in eastern Nevada. The UNR active system consists of three CEM and nylon filters (with backups in series to catch break through) sampling at a rate of 1 Lpm for 1-to-4 weeks. A Tekran total Hg system (Model 2600) was used for analyses of CEM filters from the two membrane systems after digestion. Lead isotope samples from the TAPI were analyzed on a multi-collector ICPMS (IsoProbe). Both the TAPI system and the UNR active system should collect reactive mercury (RM=GOM+PBM) on the CEM filters. TAPI measurements differed from those obtained using the Tekran system depending on season at the low elevation site and were lower than the UNR active system at the highway-impacted site and the high elevation site. We hypothesize that, due to the high flow rate and therefore short retention time, the TAPI captures mainly PBM. Lead isotopes and the chemical forms of GOM measured with the UNR active system can be used to track sources, which is important in rural areas such as GBNP.

  4. Mercury's Dynamic Magnetic Tail

    NASA Technical Reports Server (NTRS)

    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.

  5. Mercury Metadata Toolset

    Energy Science and Technology Software Center (ESTSC)

    2009-09-08

    Mercury is a federated metadata harvesting, search and retrieval tool based on both open source software and software developed at Oak Ridge National Laboratory. It was originally developed for NASA, and the Mercury development consortium now includes funding from NASA, USGS, and DOE. A major new version of Mercury (version 3.0) was developed during 2007 and released in early 2008. This Mercury 3.0 version provides orders of magnitude improvements in search speed, support for additionalmore » metadata formats, integration with Google Maps for spatial queries, facetted type search, support for RSS delivery of search results, and ready customization to meet the needs of the multiple projects which use Mercury. For the end users, Mercury provides a single portal to very quickly search for data and 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.« less

  6. Mercury Metadata Toolset

    SciTech Connect

    2009-09-08

    Mercury is a federated metadata harvesting, search and retrieval tool based on both open source software and software developed at Oak Ridge National Laboratory. It was originally developed for NASA, and the Mercury development consortium now includes funding from NASA, USGS, and DOE. A major new version of Mercury (version 3.0) was developed during 2007 and released in early 2008. This Mercury 3.0 version 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 delivery of search results, and ready customization to meet the needs of the multiple projects which use Mercury. For the end users, Mercury provides a single portal to very quickly search for data and 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.

  7. ANL computer controlled target storage system: Status report

    SciTech Connect

    Klimczak, G.W.; Nardi, B.G.; Travis, D.J.

    1986-01-01

    Design and operation of an isotopic target storage system is described. Due to the cost and effort associated with nuclear target production, it is necessary to protect them. The storage system described was designed to protect up to 90 hydroscopic and readily oxidizing targets under vacuum of 10/sup -6/ torr. The computer controller maintains system integrity during normal use and emergency situations. (JDH)

  8. Gastrointestinal absorption of metallic mercury.

    PubMed

    Sandborgh-Englund, Gunilla; Einarsson, Curt; Sandström, Magnus; Ekstrand, Jan

    2004-09-01

    The absorption of mercury from the gastrointestinal systems of 7 subjects, of whom none had any amalgam fillings, was examined in this study. The authors obtained quantitative information about mercury concentration in plasma and duodenal fluid after the gastrointestinal systems of the subjects were exposed to liquid elemental mercury enclosed in rubber balloons (i.e., approximately 20 g of mercury), using a standard procedure followed for the sampling of bile. Plasma samples were collected prior to exposure, as well as up to 10 d following exposure, and duodenal fluid was collected 1 h, 2 h, 4 h, and 6 h during the intubation process. The authors studied the kinetics of dissolution in vitro by leaching elemental liquid mercury and mercuric chloride. The results of this study supported the hypothesis that metallic mercury is oxidized in the gastrointestinal tract. In addition, the authors determined that duodenal intubation, while using liquid metallic mercury in rubber bags, resulted in the diffusion of minor amounts of atomic elemental mercury through the rubber walls. The absorbed amount of mercury that reached the central circulation was comparable to a daily dose of mercury from dental amalgam in the amalgam-bearing population. PMID:16381485

  9. The Jefferson Lab Hall A Polarized He-3 Target System

    SciTech Connect

    Todd Averett

    2003-01-01

    An optically-pumped spin-exchange polarized 3He target system was recently used for two experiments in Hall A at Jefferson Lab. The average target polarization was 41% and the error in target polarization was less than 4% (relative). The target was operated nearly continuously for a period of 3 months with an average beam current of 10-12 pA. This high level of target performance represents a new standard for these type of targets. A summary of the target system and performance is presented.

  10. Mercury volatilization by R factor systems in Escherichia coli isolated from aquatic environments of India.

    PubMed

    Gupta, Neerja; Ali, Arif

    2004-02-01

    Ten Escherichia coli strains isolated from five different aquatic environments representing three distinct geographical regions of India showed significantly high levels of tolerance to the inorganic form of mercury, i.e., mercuric chloride (HgCl(2)). MRD14 isolated from the Dal Lake (Kashmir) could tolerate the highest concentration of HgCl(2), i.e., 55 microg/mL, and MRF1 from the flood water of the Yamuna River (Delhi) tolerated the lowest concentration, i.e., 25 microg/mL. All ten strains revealed the presence of a plasmid of approximately 24 kb, and transformation of the isolated plasmids into the mercury-sensitive competent cells of E. coli DH5alpha rendered the transformants resistant to the same concentration of mercury as the wild-type strains. Mating experiments were performed to assess the self-transmissible nature of these promiscuous plasmids. The transfer of mercury resistance from these wild-type strains to the mercury-sensitive, naladixic acid-resistant E. coli K12 (F(-) lac(+)) strain used as a recipient was observed in six of the nine strains tested. Transconjugants revealed the presence of a plasmid of approximately 24 kb. An evaluation of the mechanism of mercury resistance in the three most efficient strains (MRG12, MRD11, and MRD14) encountered in our study was determined by cold vapor atomic absorption spectroscopy (CV-AAS), and it was noted that resistance to HgCl(2) was conferred by conversion of the toxic ionic form of mercury (Hg(++)) to the nontoxic elemental form (Hg(0)) in all three strains. MRD14 volatilized mercury most efficiently. PMID:15057474

  11. EMMMA: A web-based system for environmental mercury mapping, modeling, and analysis

    USGS Publications Warehouse

    Hearn,, Paul P., Jr.; Wente, Stephen P.; Donato, David I.; Aguinaldo, John J.

    2006-01-01

    tissue, atmospheric emissions and deposition, stream sediments, soils, and coal) and mercuryrelated data (mine locations); 2) Interactively view and access predictions of the National Descriptive Model of Mercury in Fish (NDMMF) at 4,976 sites and 6,829 sampling events (events are unique combinations of site and sampling date) across the United States; and 3) Use interactive mapping and graphing capabilities to visualize spatial and temporal trends and study relationships between mercury and other variables.

  12. Propulsion Systems Integration for a `Tractor Beam' Mercury Lightcraft: Liftoff Engine

    NASA Astrophysics Data System (ADS)

    Myrabo, L. N.

    2003-05-01

    Described herein is the concept and propulsion systems integration for a revolutionary beam-propelled shuttle called the ``Mercury'' lightcraft - emphasizing the liftoff engine mode. This one-person, ultra-energetic vehicle is designed to ride `tractor beams' into space, transmitted from a future network of satellite solar power stations. The objective is to create a safe, very low cost (e.g., 1000X below chemical rockets) space transportation system for human life, one that is completely `green' and independent of Earth's limited fossil fuel reserves. The lightcraft's airbreathing combined-cycle engine operates in a rotary pulsed detonation mode PDE for lift-offs and landings; at hypersonic speeds it transitions into a magnetohydrodynamic (MHD) slipstream accelerator mode. For the latter, the transatmospheric flight path is momentarily transformed into an extremely long, electromagnetic ``mass-driver'' channel with an effective `fuel' specific impulse in the range of 6000 to 16,000 seconds. These future single-stage-to-orbit, highly-reusuable vehicles will ride ``Highways of Light,'' accelerating at 3 Gs into space, with their throttles just barely beyond `idle' power.

  13. Revised Age Constraints on Absolute Age Limits for Mercury's Kuiperian and Mansurian Systems

    NASA Astrophysics Data System (ADS)

    Banks, Maria E.; Zhiyong, Xiao; Braden, Sarah E.; Marchi, Simone S.; Barlow, Nadine G.; Chapman, Clark R.; Fassett, Caleb I.

    2015-11-01

    On the basis of morphologically distinct basin and crater deposits, Mercury’s surface units have been subdivided into five time-stratigraphic systems (youngest to oldest): Kuiperian, Mansurian, Calorian, Tolstojan, and pre-Tolstojan. Approximate age limits were initially suggested for these systems on the basis of the lunar-derived impact-flux history. High-resolution and multi-band image data obtained by the MErcury Surface, Space ENviroment, GEochemistry, and Ranging (MESSENGER) spacecraft were used to catalogue fresh impact craters interpreted to have formed during the Mansurian and Kuiperian systems. Mansurian and Kuiperian craters are characterized as morphologically fresh with crisp morphologies, well-preserved rims, few or no superposed craters, continuous ejecta with radial lineaments, and well-defined secondary craters; Kuiperian craters have bright ray systems while Mansurian craters maintain fresh morphologies but no longer have discernable ray systems.The density of fresh craters in these datasets, along with the recent production and chronology function of Marchi et al. [2009], are used to estimate new limits for the boundaries of the two most recent of Mercury’s systems. Given the effects of strength and other parameters (such as density), we estimate a model age for the population of craters that have formed since the onset of the Mansurian of ~1.9 ±0.3 Gyr. Likewise we estimate a model age for the population of craters that have formed since the onset of the Kuiperian of ~300 ±40 Myr. A particularly good fit for the Mansurian crater size frequency distribution (SFD) was found for the NEO-derived crater distribution. The same is true for the Kuiperian SFD, although the fit is not as robust as for the Mansurian SFD.

  14. Demonstration of Mer-Cure Technology for Enhanced Mercury Control

    SciTech Connect

    John Marion; Dave O'Neill; Kevin Taugher; Shin Kang; Mark Johnson; Gerald Pargac; Jane Luedecke; Randy Gardiner; Mike Silvertooth; Jim Hicks; Carl Edberg; Ray Cournoyer; Stanley Bohdanowicz; Ken Peterson; Kurt Johnson; Steve Benson; Richard Schulz; Don McCollor; Mike Wuitshick

    2008-06-01

    Alstom Power Inc. has completed a DOE/NETL-sponsored program (under DOE Cooperative Agreement No. De-FC26-07NT42776) to demonstrate Mer-Cure{trademark}, one of Alstom's mercury control technologies for coal-fired boilers. The Mer-Cure{trademark}system utilizes a small amount of Mer-Clean{trademark} sorbent that is injected into the flue gas stream for oxidation and adsorption of gaseous mercury. Mer-Clean{trademark} sorbents are carbon-based and prepared with chemical additives that promote oxidation and capture of mercury. The Mer-Cure{trademark} system is unique in that the sorbent is injected into an environment where the mercury capture kinetics is accelerated. The full-scale demonstration program originally included test campaigns at two host sites: LCRA's 480-MW{sub e} Fayette Unit No.3 and Reliant Energy's 190-MW{sub e} Shawville Unit No.3. The only demonstration tests actually done were the short-term tests at LCRA due to budget constraints. This report gives a summary of the demonstration testing at Fayette Unit No.3. The goals for this Mercury Round 3 program, established by DOE/NETL under the original solicitation, were to reduce the uncontrolled mercury emissions by 90% at a cost significantly less than 50% of the previous target of $60,000/lb mercury removed. The results indicated that Mer-Cure{trademark} technology could achieve mercury removal of 90% based on uncontrolled stack emissions. The estimated costs for 90% mercury control, at a sorbent cost of $0.75 to $2.00/lb respectively, were $13,400 to $18,700/lb Hg removed. In summary, the results from demonstration testing show that the goals established by DOE/NETL were met during this test program. The goal of 90% mercury reduction was achieved. Estimated mercury removal costs were 69-78% lower than the benchmark of $60,000/lb mercury removed, significantly less than 50% of the baseline removal cost.

  15. Mercury Emission Measurement in Coal-Fired Boilers by Continuous Mercury Monitor and Ontario Hydro Method

    NASA Astrophysics Data System (ADS)

    Zhu, Yanqun; Zhou, Jinsong; He, Sheng; Cai, Xiaoshu; Hu, Changxin; Zheng, Jianming; Zhang, Le; Luo, Zhongyang; Cen, Kefa

    2007-06-01

    The mercury emission control approach attaches more importance. The accurate measurement of mercury speciation is a first step. Because OH method (accepted method) can't provide the real-time data and 2-week time for results attained, it's high time to seek on line mercury continuous emission monitors(Hg-CEM). Firstly, the gaseous elemental and oxidized mercury were conducted to measure using OH and CEM method under normal operation conditions of PC boiler after ESP, the results between two methods show good consistency. Secondly, through ESP, gaseous oxidized mercury decrease a little and particulate mercury reduce a little bit, but the elemental mercury is just the opposite. Besides, the WFGD system achieved to gaseous oxidized mercury removal of 53.4%, gaseous overall mercury and elemental mercury are 37.1% and 22.1%, respectively.

  16. Mercury Methylation and Environmental Effects of Inactive Mercury Mines in the Circum-Pacific Region

    NASA Astrophysics Data System (ADS)

    Gray, J. E.

    2001-05-01

    Mercury mines worldwide contain of some the highest concentrations of mercury on earth, and as a result of local mercury contamination, these mines represent areas of environmental concern when mine-drainage enters downstream aquatic systems. The most problematic aspect of mine site mercury contamination is the conversion of inorganic mercury to highly toxic organic mercury compounds, such as methylmercury, and their subsequent uptake by aquatic organisms in surrounding ecosystems. Mercury and methylmercury concentrations were measured in sediment and water samples collected from several inactive mercury mines in Nevada, Alaska, and the Philippines, which are part of the circum-Pacific mineral belt. The mines studied represent different mercury deposit types and sizes, and climatic settings. Geochemical data collected from these mines indicate that areas surrounding hot-springs type mercury deposits generally have lower methylmercury concentrations than silica-carbonate mercury deposits. In hot-springs mercury deposits in Nevada and Alaska, ore is dominantly cinnabar with few acid-water generating minerals such as pyrite, and as a result, mine-water drainage has near neutral pH in which there is low solubility of mercury. Conversely, silica-carbonate deposits, such as Palawan, Philippines, contain abundant cinnabar and pyrite, and the resultant acidic-mine drainage generally has higher concentrations of mercury and methylmercury. Additional factors such as the proximity of mercury mines to wetlands, climatic effects, or mine wastes containing highly soluble mercury compounds potentially enhance mercury methylation. The Palawan mercury mine may be a unique example where several adverse environmental factors produced local mercury contamination, high mercury methylation, fish contamination, and mercury poisoning of humans that consumed these contaminated fish.

  17. Hitting the Target: Target Setting and Information Systems for the Learning and Skills Sector.

    ERIC Educational Resources Information Center

    Owen, Jane; Alterman, Jeff

    The use of target setting in conjunction with good information systems in colleges and work-based learning (WBL) providers can lead to improved service provisions across the sector in the United Kingdom. Target setting must be carried out in a systematic way in which providers must develop target- setting processes with a focus on learner success;…

  18. X-ray fluorescence mapping of mercury on suspended mineral particles and diatoms in a contaminated freshwater system

    DOE PAGESBeta

    Gu, B.; Mishra, B.; Miller, C.; Wang, W.; Lai, B.; Brooks, S. C.; Kemner, K. M.; Liang, L.

    2014-05-23

    Mercury (Hg) bioavailability and geochemical cycling is affected by its partitioning between the aqueous and particulate phases. We applied X-ray fluorescence (XRF) microprobes to directly visualize and quantify the spatial localization of Hg and its correlations with other elements of interest on suspended particles from a Hg contaminated freshwater system. Up to 175 μg g–1 Hg is found on suspended particles. Mercury is heterogeneously distributed among phytoplankton (e.g., diatoms) and mineral particles that are rich in iron oxides and natural organic matter (NOM), possibly as Hg-NOM-iron oxide ternary complexes. The diatom-bound Hg is mostly found on outer surfaces of themore » cells, suggesting passive sorption of inorganic Hg on diatoms. Our results indicate that localized sorption of Hg onto suspended particles, including diatoms and NOM-coated oxide minerals, is an important sink for Hg in natural aquatic environments.« less

  19. X-ray fluorescence mapping of mercury on suspended mineral particles and diatoms in a contaminated freshwater system

    SciTech Connect

    Gu, Baohua; Mishra, Bhoopesh; Miller, Carrie L; Wang, Wei; Lai, Barry; Brooks, Scott C; Kemner, Kenneth M; Liang, Liyuan

    2014-01-01

    Mercury (Hg) bioavailability and geochemical cycling is affected by its partitioning between the aqueous and particulate phases. We applied X-ray fluorescence (XRF) microprobes to directly visualize and quantify the spatial localization of Hg and its correlations with other elements of interest on suspended particles from a Hg contaminated freshwater system. Up to 175 g/g Hg is found on suspended particles. Mercury is heterogeneously distributed among phytoplankton (e.g., diatoms) and mineral particles that are rich in iron oxides and natural organic matter (NOM), possibly as Hg-NOM-iron oxide ternary complexes. The diatom-bound Hg is mostly found on outer surfaces of the cells, suggesting passive sorption of inorganic Hg on diatoms. Our results indicate that localized sorption of Hg onto suspended particles, including diatoms and NOM-coated oxide minerals, is an important sink for Hg in natural aquatic environments.

  20. A solid target system with remote handling of irradiated targets for PET cyclotrons.

    PubMed

    Siikanen, J; Tran, T A; Olsson, T G; Strand, S-E; Sandell, A

    2014-12-01

    A solid target system was developed for a PET cyclotron. The system is compatible with many different target materials in the form of foils and electroplated/sputtered targets which makes it useful for production of a wide variety of different PET radionuclides. The target material is manually loaded into the system. Remote handling of irradiated target material is managed with a pneumatic piston and a vacuum technique which allows the targets to be dropped into a shielded transport container. To test the target performance, proton irradiations (12.8 MeV, 45 μA) of monoisotopic yttrium foils (0.64 mm, direct water cooling) were performed to produce 89Zr. The yields were 2200±200 MBq (1 h, n=13) and 6300±65 MBq (3 h, n=3). PMID:25265518

  1. Gold nanospikes based microsensor as a highly accurate mercury emission monitoring system

    NASA Astrophysics Data System (ADS)

    Sabri, Ylias M.; Ippolito, Samuel J.; Tardio, James; Bansal, Vipul; O'Mullane, Anthony P.; Bhargava, Suresh K.

    2014-10-01

    Anthropogenic elemental mercury (Hg0) emission is a serious worldwide environmental problem due to the extreme toxicity of the heavy metal to humans, plants and wildlife. Development of an accurate and cheap microsensor based online monitoring system which can be integrated as part of Hg0 removal and control processes in industry is still a major challenge. Here, we demonstrate that forming Au nanospike structures directly onto the electrodes of a quartz crystal microbalance (QCM) using a novel electrochemical route results in a self-regenerating, highly robust, stable, sensitive and selective Hg0 vapor sensor. The data from a 127 day continuous test performed in the presence of volatile organic compounds and high humidity levels, showed that the sensor with an electrodeposted sensitive layer had 260% higher response magnitude, 3.4 times lower detection limit (~22 μg/m3 or ~2.46 ppbv) and higher accuracy (98% Vs 35%) over a Au control based QCM (unmodified) when exposed to a Hg0 vapor concentration of 10.55 mg/m3 at 101°C. Statistical analysis of the long term data showed that the nano-engineered Hg0 sorption sites on the developed Au nanospikes sensitive layer play a critical role in the enhanced sensitivity and selectivity of the developed sensor towards Hg0 vapor.

  2. Gold nanospikes based microsensor as a highly accurate mercury emission monitoring system

    PubMed Central

    Sabri, Ylias M.; Ippolito, Samuel J.; Tardio, James; Bansal, Vipul; O'Mullane, Anthony P.; Bhargava, Suresh K.

    2014-01-01

    Anthropogenic elemental mercury (Hg0) emission is a serious worldwide environmental problem due to the extreme toxicity of the heavy metal to humans, plants and wildlife. Development of an accurate and cheap microsensor based online monitoring system which can be integrated as part of Hg0 removal and control processes in industry is still a major challenge. Here, we demonstrate that forming Au nanospike structures directly onto the electrodes of a quartz crystal microbalance (QCM) using a novel electrochemical route results in a self-regenerating, highly robust, stable, sensitive and selective Hg0 vapor sensor. The data from a 127 day continuous test performed in the presence of volatile organic compounds and high humidity levels, showed that the sensor with an electrodeposted sensitive layer had 260% higher response magnitude, 3.4 times lower detection limit (~22 μg/m3 or ~2.46 ppbv) and higher accuracy (98% Vs 35%) over a Au control based QCM (unmodified) when exposed to a Hg0 vapor concentration of 10.55 mg/m3 at 101°C. Statistical analysis of the long term data showed that the nano-engineered Hg0 sorption sites on the developed Au nanospikes sensitive layer play a critical role in the enhanced sensitivity and selectivity of the developed sensor towards Hg0 vapor. PMID:25338965

  3. Mercury concentrations and loads in a large river system tributary to San Francisco Bay, California, USA

    USGS Publications Warehouse

    David, N.; McKee, L.J.; Black, F.J.; Flegal, A.R.; Conaway, C.H.; Schoellhamer, D.H.; Ganju, N.K.

    2009-01-01

    In order to estimate total mercury (HgT) loads entering San Francisco Bay, USA, via the Sacramento-San Joaquin River system, unfiltered water samples were collected between January 2002 and January 2006 during high flow events and analyzed for HgT. Unfiltered HgT concentrations ranged from 3.2 to 75 ng/L and showed a strong correlation (r2 = 0.8, p < 0.001, n = 78) to suspended sediment concentrations (SSC). During infrequent large floods, HgT concentrations relative to SSC were approximately twice as high as observed during smaller floods. This difference indicates the transport of more Hg-contaminated particles during high discharge events. Daily HgT loads in the Sacramento-San Joaquin River at Mallard Island ranged from below the limit of detection to 35 kg. Annual HgT loads varied from 61 ?? 22 kg (n = 5) in water year (WY) 2002 to 470 ?? 170 kg (n = 25) in WY 2006. The data collected will assist in understanding the long-term recovery of San Francisco Bay from Hg contamination and in implementing the Hg total maximum daily load, the long-term cleanup plan for Hg in the Bay. ?? 2009 SETAC.

  4. Successful completion of a cyclic ground test of a mercury Ion Auxiliary Propulsion System

    NASA Technical Reports Server (NTRS)

    Francisco, David R.; Low, Charles A., Jr.; Power, John L.

    1988-01-01

    An engineering model Ion Auxiliary Propulsion System (IAPS) 8-cm thruster (S/N 905) has completed a life test at NASA Lewis Research Center. The mercury ion thruster successfully completed and exceeded the test goals of 2557 on/off cycles and 7057 hr of operation at full thrust. The final 1200 cycles and 3600 hr of the life test were conducted using an engineering model of the IAPS power electronics unit (PEU) and breadboard digital controller and interface unit (DCIU). This portion of the test is described in this paper with a charted history of thruster operating parameters and off-normal events. Performance and operating characteristics were constant throughout the test with only minor variations. The engineering model power electronics unit operated without malfunction; the flight software in the digital controller and interface unit was exercised and verified. Post-test inspection of the thruster revealed facility enhanced accelerator grid erosion but overall the thruster was in good condition. It was concluded that the thruster performance was not drastically degraded by time or cycles. Additional cyclic testing is currently under consideration.

  5. Successful completion of a cyclic ground test of a mercury ion auxiliary propulsion system

    NASA Technical Reports Server (NTRS)

    Francisco, David R.; Low, Charles A., Jr.; Power, John L.

    1988-01-01

    An engineering model Ion Auxiliary Propulsion System (IAPS) 8-cm thruster (S/N 905) has completed a life test at NASA Lewis Research Center. The mercury ion thruster successfully completed and exceeded the test goals of 2557 on/off cycles and 7057 hr of operation at full thrust. The final 1200 cycles and 3600 hr of the life test were conducted using an engineering model of the IAPS power electronics unit (PEU) and breadboard digital controller and interface unit (DCIU). This portion of the test is described in this paper with a charted history of thruster operating parameters and off-normal events. Performance and operating characteristics were constant throughout the test with only minor variations. The engineering model power electronics unit operated without malfunction; the flight software in the digital controller and interface unit was exercised and verified. Post-test inspection of the thruster revealed facility enhanced accelerator grid erosion but overall the thruster was in good condition. It was concluded that the thruster performance was not drastically degraded by time or cycles. Additional cyclic testing is currently under consideration.

  6. To Mercury dynamics

    NASA Astrophysics Data System (ADS)

    Barkin, Yu. V.; Ferrandiz, J. M.

    Present significance of the study of rotation of Mercury considered as a core-mantle system arises from planned Mercury missions. New high accurate data on Mercury's structure and its physical fields are expected from BepiColombo mission (Anselmi et al., 2001). Investigation of resonant rotation of Mercury, begun by Colombo G. (1966), will play here main part. New approaches to the study of Mercury dynamics and the construction of analytical theory of its resonant rotation are suggested. Within these approaches Mercury is considered as a system of two non-spherical interacting bodies: a core and a mantle. The mantle of Mercury is considered as non-spherical, rigid (or elastic) layer. Inner shell is a liquid core, which occupies a large ellipsoidal cavity of Mercury. This Mercury system moves in the gravitational field of the Sun in resonant traslatory-rotary regime of the resonance 3:2. We take into account only the second harmonic of the force function of the Sun and Mercury. For the study of Mercury rotation we have been used specially designed canonical equations of motion in Andoyer and Poincare variables (Barkin, Ferrandiz, 2001), more convenient for the application of mentioned methods. Approximate observational and some theoretical evaluations of the two main coefficients of Mercury gravitational field J_2 and C22 are known. From observational data of Mariner-10 mission were obtained some first evaluations of these coefficients: J_2 =(8± 6)\\cdot 10-5(Esposito et al., 1977); J_2 =(6± 2)\\cdot 10-5and C22 =(1.0± 0.5)\\cdot 10-5(Anderson et al., 1987). Some theoretical evaluation of ratio of these coefficients has been obtained on the base of study of periodic motions of the system of two non-spherical gravitating bodies (Barkin, 1976). Corresponding values of coefficients consist: J_2 =8\\cdot 10-5and C22 =0.33\\cdot 10-5. We have no data about non-sphericity of inner core of Mercury. Planned missions to Mercury (BepiColombo and Messenger) promise to

  7. Optoelectronic System Measures Distances to Multiple Targets

    NASA Technical Reports Server (NTRS)

    Liebe, Carl Christian; Abramovici, Alexander; Bartman, Randall; Chapsky, Jacob; Schmalz, John; Coste, Keith; Litty, Edward; Lam, Raymond; Jerebets, Sergei

    2007-01-01

    An optoelectronic metrology apparatus now at the laboratory-prototype stage of development is intended to repeatedly determine distances of as much as several hundred meters, at submillimeter accuracy, to multiple targets in rapid succession. The underlying concept of optoelectronic apparatuses that can measure distances to targets is not new; such apparatuses are commonly used in general surveying and machining. However, until now such apparatuses have been, variously, constrained to (1) a single target or (2) multiple targets with a low update rate and a requirement for some a priori knowledge of target geometry. When fully developed, the present apparatus would enable measurement of distances to more than 50 targets at an update rate greater than 10 Hz, without a requirement for a priori knowledge of target geometry. The apparatus (see figure) includes a laser ranging unit (LRU) that includes an electronic camera (photo receiver), the field of view of which contains all relevant targets. Each target, mounted at a fiducial position on an object of interest, consists of a small lens at the output end of an optical fiber that extends from the object of interest back to the LRU. For each target and its optical fiber, there is a dedicated laser that is used to illuminate the target via the optical fiber. The targets are illuminated, one at a time, with laser light that is modulated at a frequency of 10.01 MHz. The modulated laser light is emitted by the target, from where it returns to the camera (photodetector), where it is detected. Both the outgoing and incoming 10.01-MHz laser signals are mixed with a 10-MHz local-oscillator to obtain beat notes at 10 kHz, and the difference between the phases of the beat notes is measured by a phase meter. This phase difference serves as a measure of the total length of the path traveled by light going out through the optical fiber and returning to the camera (photodetector) through free space. Because the portion of the path

  8. Remote weapon station for automatic target recognition system demand analysis

    NASA Astrophysics Data System (ADS)

    Lei, Zhang; Li, Sheng-cai; Shi, Cai

    2015-08-01

    Introduces a remote weapon station basic composition and the main advantage, analysis of target based on image automatic recognition system for remote weapon station of practical significance, the system elaborated the image based automatic target recognition system in the photoelectric stabilized technology, multi-sensor image fusion technology, integrated control target image enhancement, target behavior risk analysis technology, intelligent based on the character of the image automatic target recognition algorithm research, micro sensor technology as the key technology of the development in the field of demand.

  9. Observer's Interface for Solar System Target Specification

    NASA Astrophysics Data System (ADS)

    Roman, Anthony; Link, Miranda; Moriarty, Christopher; Stansberry, John A.

    2016-01-01

    When observing an asteroid or comet with HST, it has been necessary for the observer to manually enter the target's orbital elements into the Astronomer's Proposal Tool (APT). This allowed possible copy/paste transcription errors from the observer's source of orbital elements data. In order to address this issue, APT has now been improved with the capability to identify targets in and then download orbital elements from JPL Horizons. The observer will first use a target name resolver to choose the intended target from the Horizons database, and then download the orbital elements from Horizons directly into APT. A manual entry option is also still retained if the observer does not wish to use elements from Horizons. This new capability is available for HST observing, and it will also be supported for JWST observing. The poster shows examples of this new interface.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. Mercury, cadmium and lead biogeochemistry in the soil-plant-insect system in Huludao City.

    PubMed

    Zhang, Zhong-Sheng; Lu, Xian-Guo; Wang, Qi-Chao; Zheng, Dong-Mei

    2009-08-01

    Mercury, cadmium, and lead concentrations of ashed plants and insects samples were investigated and compared with those of soil to reveal their biogeochemical processes along food chains in Huludao City, Liaoning Province, China. Concentration factors of each fragments of the soil-plant-the herbivorous insect-the carnivorous insect food chain were 0.18, 6.57, and 7.88 for mercury; 6.82, 2.01, and 0.48 for cadmium; 1.47, 2.24, and 0.57 for lead, respectively. On the whole, mercury was the most largely biomagnified, but cadmium and lead were not greatly accumulated in the carnivorous insects as expected when the food chain extended to the secondary consumers. Results indicated that concentration factors depended on metals and insects species of food chains. PMID:19280090

  12. 3. Mercury pollution in the Lot River system (France): fluxes and sedimentary record.

    NASA Astrophysics Data System (ADS)

    Schäfer, J.; Blanc, G.; Audry, S.; Bossy, C.; Vu Duc, L.; Lissalde, J.-P.

    2003-04-01

    We present first data on Hg concentrations and fluxes in the Lot River system (southwest France), known for its historic Zn and Cd pollution affecting seafood production in the Gironde Estuary. Present day Hg fluxes (1999-2000) were estimated from daily measured discharge and SPM concentrations and concentrations of particulate and dissolved Hg in monthly collected samples. The data show that Hg is essentially (up to 98 %) transported in the particulate phase. Particulate Hg concentrations in SPM show a distinct decrease between 1992 and 1999 but, since then, tend to increase in magnitude and variability. The evolution of Hg fluxes in the Lot River in 1992, 1994, 1995 and 1998-2001 reflect hydrological variations and the decrease of direct Hg inputs from the point source at the Riou-Mort River, draining a small watershed polluted by former mining and ore treatment. However, the data also indicate important Hg remobilization from the sediment by dredging due to lock construction along the Lot River. Mercury concentrations in sediment cores from a dam lake downstream of the Riou-Mort watershed are up to 30 mg.kg-1, i.e. more than 300-fold higher than geochemical background measured in the same riverbed upstream the confluence with the Riou-Mort River. In the sediment cores Hg from the Lot River dam lakes Hg concentration profiles are comparable to those of Cd and Zn. This indicates common sources and transport. Element ratios (e.g. Cd/Zn) in the sediment reflect SPM values and suggest an important Hg stock (7 t) in these sediments. Historic (˜40 years) Hg records in the sediment cores dated by using 137Cs activities and Cd-concentrations (e.g. Chernobyl accident and accidental Cd pollution in 1986) confirm the decreasing Hg level in SPM since the early nineties. Nevertheless Hg concentrations in the upper sediment and SPM remain high compared to background values from reference sites in the upper Lot River system.

  13. Pressure waves in liquid mercury target from pulsed heat loads and the possible way controlling their effects

    SciTech Connect

    Ni, L.; Skala, K.

    1996-06-01

    In ESS project liquid metals are selected as the main target for the pulsed spallation neutron source. Since the very high instantaneous energy is deposited on the heavy molten target in a very short period time, pressure waves are generated. They travel through the liquid and cause high stress in the container. Also, additional stress should be considered in the wall which is the result of direct heating of the target window. These dynamic processes were simulated with computational codes with the static response being analized first. The total resulting dynamic wall stress has been found to have exceeded the design stress for the selected container material. Adding a small amount of gas bubbles in the liquid could be a possible way to reduce the pressure waves.

  14. Human Exposure and Health Effects of Inorganic and Elemental Mercury

    PubMed Central

    Zheng, Wei

    2012-01-01

    Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety. PMID:23230464

  15. Inhalation of mercury vapor can cause the toxic effects on rat kidney.

    PubMed

    Akgül, Nilgün; Altunkaynak, Berrin Zuhal; Altunkaynak, Muhammed Eyüp; Deniz, Ömür Gülsüm; Ünal, Deniz; Akgül, Hayati Murat

    2016-01-01

    Dental amalgam has been used in dentistry as a filling material. The filler comprises mercury (Hg). It is considered one of the most important and widespread environmental pollutants, which poses a serious potential threat for the humans and animals. However, mercury deposition affects the nervous, cardiovascular, pulmonary, gastrointestinal, and especially renal systems. In most animals' species and humans, the kidney is one of the main sites of deposition of mercury and target organ for its toxicity. In this study, the effects of mercury intake on kidney in rats were searched. For the this purpose; we used 24 adult female Wistar albino rats (200 g in weight) obtained from Experimental Research and Application Center of Atatürk University with ethical approval. Besides, they were placed into a specially designed glass cage. Along this experiment for 45 days, subjects were exposed to (1 mg/m(3)/day) mercury vapor. However, no application was used for the control subjects. At the end of the experiment, kidney samples were obtained from all subjects and processed for routine light microscopic level and stereological aspect were assessed. Finally, according to our results, mercury affects the histological features of the kidney. That means, the severe effects of mercury has been shown using stereological approach, which is one of the ideal quantitative methods in the current literature. In this study, it was detected that chronic exposure to mercury vapor may lead to renal damage and diseases in an experimental rat model. PMID:26888214

  16. Repetitive output laser system and method using target reflectivity

    DOEpatents

    Johnson, Roy R.

    1978-01-01

    An improved laser system and method for implosion of a thermonuclear fuel pellet in which that portion of a laser pulse reflected by the target pellet is utilized in the laser system to initiate a succeeding target implosion, and in which the energy stored in the laser system to amplify the initial laser pulse, but not completely absorbed thereby, is used to amplify succeeding laser pulses initiated by target reflection.

  17. THE EFFECT OF MERCURY CONTROLS ON WALLBOARD MANUFACTURE

    SciTech Connect

    Sandra Meischen

    2004-07-01

    Pending EPA regulations may mandate 70 to 90% mercury removal efficiency from utility flue gas. A mercury control option is the trapping of oxidized mercury in wet flue gas desulfurization systems (FGD). The potential doubling of mercury in the FGD material and its effect on mercury volatility at temperatures common to wallboard manufacture is a concern that could limit the growing byproduct use of FGD material. Prediction of mercury fate is limited by lack of information on the mercury form in the FGD material. The parts per billion mercury concentrations prevent the identification of mercury compounds by common analytical methods. A sensitive analytical method, cold vapor atomic fluorescence, coupled with leaching and thermodecomposition methods were evaluated for their potential to identify mercury compounds in FGD material. The results of the study suggest that the mercury form is dominated by the calcium sulfate matrix and is probably associated with the sulfate form in the FGD material. Additionally, to determine the effect of high mercury concentration FGD material on wallboard manufacture, a laboratory FGD unit was built to trap the oxidized mercury generated in a simulated flue gas. Although the laboratory prepared FGD material did not contain the mercury concentrations anticipated, further thermal tests determined that mercury begins to evolve from FGD material at 380 to 390 F, consequently dropping the drying temperature should mitigate mercury evolution if necessary. Mercury evolution is also diminished as the weight of the wallboard sample increased. Consequently, mercury evolution may not be a significant problem in wallboard manufacture.

  18. Finding a Target with an Accessible Global Positioning System

    ERIC Educational Resources Information Center

    Ponchillia, Paul E.; MacKenzie, Nancy; Long, Richard G.; Denton-Smith, Pamela; Hicks, Thomas L.; Miley, Priscilla

    2007-01-01

    This article presents two target-location experiments. In the first experiment, 19 participants located a 25-foot chalk circle 93% of the time with a Global Positioning System (GPS) compared to 12% of the time without it. In a single-subject follow-up experiment, the participant came within 1 foot of the target on all GPS trials. Target-location…

  19. Mercury methylation by fish intestinal contents

    SciTech Connect

    Rudd, J.W.M.; Furutani, A.; Turner, M.A.

    1980-10-01

    Microbial methylation of mercury is a severe environmental problem. A new radiochemical method was applied to determine the extent of mercury methylation in fish intestines. Fish samples were obtained from two lakes within the severely polluted Wabigoon River system in northwestern Ontario and from nearby non-mercury contaminated lakes. Intestinal contents of six freshwater fish species from both polluted and nonpolluted lakes could methylate mercury. Bacterial activity in the intestinal contents was most likely responsible for this methylation.

  20. Mercury: Exploration of a Planet

    NASA Technical Reports Server (NTRS)

    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.

  1. Mass-independent fractionation of mercury isotopes during photochemical reduction in freshwater systems

    NASA Astrophysics Data System (ADS)

    Rose, C. H.; Bergquist, B. A.; Blum, J. D.

    2009-12-01

    Mercury is a globally distributed environmental toxin. Both inorganic and methylated species have severe detrimental effects on humans and animals, but it is methyl mercury (MeHg) that bioaccumulates in food webs and results in significant human exposure via fish consumption. Photochemical reduction of aqueous Hg species to dissolved gaseous Hg(0) can result in a net transfer of Hg from aquatic systems to the atmosphere, making it unavailable for methylation. In addition, photo-reduction of MeHg is an alternative fate to bioaccumulation for this powerful neurotoxin. Both mass-dependent isotope fractionation (MDF) and mass-independent fractionation (MIF) are observed in natural samples. MIF is the deviation in isotope ratios from those predicted by MDF based on 202Hg/198Hg. Bergquist and Blum 2007 showed that aqueous photo-reduction of Hg2+ and MeHg in the presence of dissolved natural organic matter results not only in Rayleigh-type MDF but also significant MIF, with the odd isotopes 199Hg and 201Hg being preferentially retained in the reactant (soluble) phase. Berquist and Blum 2007 also observed that the ratio of the MIF for the odd isotopes was different for each of the photo-reduction pathways (MeHg versus Hg2+) and suggested this ratio could be unique to certain pathways, which might allow identification of photo-reduction among other pathways in natural samples. They also suggested that the magnitude of MIF might relate quantitatively to the amount of photo-reduction Hg undergoes in aqueous systems. To better understand the causes of MIF and its capacity along with MDF as a tool for tracing photo-reduction of Hg, further experiments mimicking the freshwater photo-reduction of Hg2+ and MeHg were carried out. Each species was photo-reduced in the presence of Suwannee River Fulvic Acid with different portions of the electromagnetic spectrum blocked by filters. Bergquist and Blum 2007 suggested the magnetic isotope effect (MIE) as the cause of the MIF they

  2. Phytoremediation of Ionic and Methyl Mercury Pollution

    SciTech Connect

    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

  3. Image guidance: treatment target localization systems.

    PubMed

    Sharpe, Michael B; Craig, Tim; Moseley, Douglas J

    2007-01-01

    Highly conformal radiation therapy tailors treatment to match the target shape and position, minimizing normal tissue damage to a greater extent than previously possible. Technological advances such as intensity-modulated radiation therapy, introduced a decade ago, have yielded significant gains in tumor control and reduced toxicity. Continuing advances have focused on the characterization and control of patient movement, organ motion, and anatomical deformation, which all introduce geometric uncertainty. These sources of uncertainty limit the effectiveness of high-precision treatment. Target localization, performed using appropriate technologies and frequency, is a critical component of treatment quality assurance. Until recently, the target position with respect to the beams has been inferred from surface marks on the patient's skin or through an immobilization device, and verified using megavoltage radiographs of the treatment portal. Advances in imaging technologies have made it possible to image soft tissue volumes in the treatment setting. Real-time tracking is also possible using a variety of technologies, including fluoroscopic imaging and radiopaque markers implanted in or near the tumor. The capacity to acquire volumetric soft tissue images in the treatment setting can also be used to assess anatomical changes over a course of treatment. Enhancing localization practices reduces treatment errors, and gives the capacity to monitor anatomical changes and reduce uncertainties that could influence clinical outcomes. This review presents the technologies available for target localization, and discusses some of the considerations that should be addressed in the implementation of many new clinical processes in radiation oncology. PMID:17641503

  4. MESSENGER: Exploring Mercury's Magnetosphere

    NASA Technical Reports Server (NTRS)

    Slavin, James A.; Krimigis, Stamatios M.; Acuna, Mario H.; Anderson, Brian J.; Baker, Daniel N.; Koehn, Patrick L.; Korth, Haje; Levi, Stefano; Mauk, Barry H.; Solomon, Sean C.; Zurbuchen, Thomas H.

    2005-01-01

    The MESSENGER mission to Mercury offers our first opportunity to explore this planet s miniature magnetosphere since the brief flybys of Mariner 10. Mercury s magnetosphere is unique in many respects. The magnetosphere of Mercury is among the smallest in the solar system; its magnetic field typically stands off the solar wind only - 1000 to 2000 km above the surface. For this reason there are no closed drift paths for energetic particles and, hence, no radiation belts. The characteristic time scales for wave propagation and convective transport are short and kinetic and fluid modes may be coupled. Magnetic reconnection at the dayside magnetopause may erode the subsolar magnetosphere allowing solar wind ions to impact directly the regolith. Inductive currents in Mercury s interior may act to modify the solar wind interaction by resisting changes due to solar wind pressure variations. Indeed, observations of these induction effects may be an important source of information on the state of Mercury s interior. 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 ionospheric layer. This lack of an ionosphere is probably the underlying reason for the brevity of the very intense, but short-lived, - 1-2 min, substorm-like energetic particle events observed by Mariner 10 during its first traversal of Mercury s magnetic tail. Because of Mercury s proximity to the sun, 0.3 - 0.5 AU, this magnetosphere experiences the most extreme driving forces in the solar system. All of these factors are expected to produce complicated interactions involving the exchange and re-cycling of neutrals and ions between the solar wind, magnetosphere, and regolith. The electrodynamics of Mercury s magnetosphere are expected to be equally complex, with strong forcing by the solar wind, magnetic reconnection at the magnetopause and in the tail, and the pick-up of planetary ions all

  5. 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

    NASA Astrophysics Data System (ADS)

    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

  6. MERCURY SPECIATION IN COMBUSTION SYSTEMS: STUDIES WITH SIMULATED FLUE GASES AND MODEL FLY ASHES

    EPA Science Inventory

    The paper gives results of a bench-scale study of the effects of flue gas and fly ash parameters on the oxidation of elemental mercury in simulated flue gases containing hydrogen chloride (HCl), nitric oxide (NO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and water vapor (H2O...

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

    NASA Astrophysics Data System (ADS)

    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

  8. Fractionation of mercury isotopes by photo-oxidation in aquatic systems

    NASA Astrophysics Data System (ADS)

    Ghosh, S.; Bergquist, B. A.; Blum, J. D.

    2009-12-01

    Mercury is a globally distributed pollutant that bioaccumulates in aquatic food webs, even in remote locations. The recent discovery of both large mass-dependent fractionation (MDF) and mass-independent fractionation (MIF) has made the promise of tracing this neurotoxin through the environment by using its isotopes very exciting. So far, the only process demonstrated experimentally to produce large MIF for Hg (similar in magnitude to the MIF observed in natural samples such as fish) is photochemical reduction (Bergquist and Blum, 2007). During photo-reduction, MIF of the odd isotopes was observed with the odd isotopes (199Hg, 201Hg) being preferentially enriched in the aqueous phase. Bergquist and Blum, 2007, suggested that the cause of MIF was the magnetic isotope effect (MIE), which is purely a kinetic phenomenon involving radical pair intermediates. Radical pairs with odd isotopes, which have non-zero nuclear spin and magnetic moments, can undergo spin conversion faster than radical pairs with non-magnetic even isotopes. This allows the odd and even isotopes to be preferentially enriched in different reaction products. MIE is a complex phenomenon that is dependent on several factors including hyperfine coupling, life-time of the radical pair, coupling strength of the radical pair, spin-orbital coupling, diffusion factors, and the solvent cage (space) in which the reaction occurs. Only under rare circumstances will all the factors be suitable for the expression of MIE in natural reactions. The goal of this study was to conduct aqueous photo-oxidation reactions to investigate whether this redox pathway expresses MIF (in the form of MIE) similar to the photo-reduction pathway. In natural systems, net photo-reduction of Hg (II) species results in the release of Hg(0) vapor to the atmosphere. However this net photo-reduction is a combination of both photo-reduction and photo-oxidation. In their experiments, Bergquist and Blum 2007, only investigated the aqueous photo

  9. FIELD TEST PROGRAM FOR LONG-TERM OPERATION OF A COHPAC SYSTEM FOR REMOVING MERCURY FROM COAL-FIRED FLUE GAS

    SciTech Connect

    Jean Bustard

    2003-06-13

    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. Sorbent injection technology represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. It involves injecting a solid material such as powdered activated carbon into the flue gas. The gas phase mercury in the flue gas contacts the sorbent and attaches to its surface. The sorbent with the mercury attached is then collected by the existing particle control device along with the other solid material, primarily fly ash. During 2001 ADA Environmental Solutions (ADA-ES) conducted a full-scale demonstration of sorbent-based mercury control technology at the Alabama Power E.C. Gaston Station (Wilsonville, AL). This unit burns a low-sulfur bituminous coal and uses a hot-side electrostatic precipitator (ESP) in combination with a COHPAC baghouse to collect fly ash. The majority of the fly ash is collected in the ESP with the residual being collected in the COHPAC baghouse. Activated carbon was injected between the ESP and COHPAC units to collect the mercury. Short-term mercury removal levels in excess of 90% were achieved using the COHPAC unit. The test also showed that activated carbon was effective on removing both forms of mercury, elemental and oxidized. However, a great deal of additional testing is required to further characterize the capabilities and limitations of this technology relative to use with baghouse systems such as COHPAC. It is important to determine performance over an extended period of time to fully assess all operational parameters. The project described in this report focuses on fully demonstrating sorbent injection technology at a coal-fired power generating plant that is equipped with a COHPAC system. The overall objective is to evaluate the

  10. FIELD TEST PROGRAM FOR LONG-TERM OPERATION OF A COHPAC SYSTEM FOR REMOVING MERCURY FROM COAL-FIRED FLUE GAS

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Trent Taylor; Cindy Larson

    2004-01-29

    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. Sorbent injection technology represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. It involves injecting a solid material such as powdered activated carbon into the flue gas. The gas-phase mercury in the flue gas contacts the sorbent and attaches to its surface. The sorbent with the mercury attached is then collected by the existing particle control device along with the other solid material, primarily fly ash. During 2001, ADA Environmental Solutions (ADA-ES) conducted a full-scale demonstration of sorbent-based mercury control technology at the Alabama Power E.C. Gaston Station (Wilsonville, AL). This unit burns a low-sulfur bituminous coal and uses a hot-side electrostatic precipitator (ESP) in combination with a Compact Hybrid Particulate Collector (COHPAC{trademark}) baghouse to collect fly ash. The majority of the fly ash is collected in the ESP with the residual being collected in the COHPAC{trademark} baghouse. Activated carbon was injected between the ESP and COHPAC{trademark} units to collect the mercury. Short-term mercury removal levels in excess of 90% were achieved using the COHPAC{trademark} unit. The test also showed that activated carbon was effective in removing both forms of mercury--elemental and oxidized. However, a great deal of additional testing is required to further characterize the capabilities and limitations of this technology relative to use with baghouse systems such as COHPAC{trademark}. It is important to determine performance over an extended period of time to fully assess all operational parameters. The project described in this report focuses on fully demonstrating sorbent injection technology at a coal-fired power

  11. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Trent Taylor; Cindy Larson

    2005-01-24

    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. Sorbent injection technology represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. It involves injecting a solid material such as powdered activated carbon into the flue gas. The gas-phase mercury in the flue gas contacts the sorbent and attaches to its surface. The sorbent with the mercury attached is then collected by the existing particle control device along with the other solid material, primarily fly ash. During 2001, ADA Environmental Solutions (ADA-ES) conducted a full-scale demonstration of sorbent-based mercury control technology at the Alabama Power E.C. Gaston Station (Wilsonville, Alabama). This unit burns a low-sulfur bituminous coal and uses a hot-side electrostatic precipitator (ESP) in combination with a Compact Hybrid Particulate Collector (COHPAC{reg_sign}) baghouse to collect fly ash. The majority of the fly ash is collected in the ESP with the residual being collected in the COHPAC{reg_sign} baghouse. Activated carbon was injected between the ESP and COHPAC{reg_sign} units to collect the mercury. Short-term mercury removal levels in excess of 90% were achieved using the COHPAC{reg_sign} unit. The test also showed that activated carbon was effective in removing both forms of mercury-elemental and oxidized. However, a great deal of additional testing is required to further characterize the capabilities and limitations of this technology relative to use with baghouse systems such as COHPAC{reg_sign}. It is important to determine performance over an extended period of time to fully assess all operational parameters. The project described in this report focuses on fully demonstrating sorbent injection technology at a coal-fired power

  12. Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

    SciTech Connect

    Jean Bustard; Charles Lindsey; Paul Brignac; Travis Starns; Sharon Sjostrom; Trent Taylor; Cindy Larson

    2004-06-04

    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. Sorbent injection technology represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. It involves injecting a solid material such as powdered activated carbon into the flue gas. The gas-phase mercury in the flue gas contacts the sorbent and attaches to its surface. The sorbent with the mercury attached is then collected by the existing particle control device along with the other solid material, primarily fly ash. During 2001, ADA Environmental Solutions (ADA-ES) conducted a full-scale demonstration of sorbent-based mercury control technology at the Alabama Power E.C. Gaston Station (Wilsonville, Alabama). This unit burns a low-sulfur bituminous coal and uses a hot-side electrostatic precipitator (ESP) in combination with a Compact Hybrid Particulate Collector (COHPAC{reg_sign}) baghouse to collect fly ash. The majority of the fly ash is collected in the ESP with the residual being collected in the COHPAC{reg_sign} baghouse. Activated carbon was injected between the ESP and COHPAC{reg_sign} units to collect the mercury. Short-term mercury removal levels in excess of 90% were achieved using the COHPAC{reg_sign} unit. The test also showed that activated carbon was effective in removing both forms of mercury-elemental and oxidized. However, a great deal of additional testing is required to further characterize the capabilities and limitations of this technology relative to use with baghouse systems such as COHPAC{reg_sign}. It is important to determine performance over an extended period of time to fully assess all operational parameters. The project described in this report focuses on fully demonstrating sorbent injection technology at a coal-fired power

  13. The Nuclotron internal target control and data acquisition system

    NASA Astrophysics Data System (ADS)

    Isupov, A. Yu.; Krasnov, V. A.; Ladygin, V. P.; Piyadin, S. M.; Reznikov, S. G.

    2013-01-01

    The new control system of the Nuclotron (JINR, Dubna) internal target is described in both hardware and software aspects. The CAMAC hardware is based on the use of the standard CAMAC modules developed and manufactured at JINR. The internal target control and data acquisition (IntTarg CDAQ) system software is implemented using the ngdp framework under the Unix-like operating system (OS) FreeBSD to allow easy network distribution of the online data collected from internal target and accompanying detectors, as well as the internal target remote control.

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

    SciTech Connect

    Caruso, Joseph A.; Stemmer, Paul M.; Dombkowski, Alan; Caruthers, Nicholas J.; Gill, Randall; Rosenspire, Allen J.

    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

  15. Target specificity of the CRISPR-Cas9 system

    PubMed Central

    Wu, Xuebing; Kriz, Andrea J.; Sharp, Phillip A.

    2015-01-01

    The CRISPR-Cas9 system, naturally a defense mechanism in prokaryotes, has been repurposed as an RNA-guided DNA targeting platform. It has been widely used for genome editing and transcriptome modulation, and has shown great promise in correcting mutations in human genetic diseases. Off-target effects are a critical issue for all of these applications. Here we review the current status on the target specificity of the CRISPR-Cas9 system. PMID:25722925

  16. Aplastic anemia and membranous nephropathy induced by intravenous mercury

    PubMed Central

    Priya, N.; Nagaprabhu, V. N.; Kurian, G.; Seethalakshmi, N.; Rao, G. G.; Unni, V. N.

    2012-01-01

    Self-injection of mercury can be life-threatening. We report a case of attempted suicide by self-intravenous injection of elemental mercury. The patient suffered from two side effects : membranous nephropathy and aplastic anemia. She was treated and the systemic effects of mercury were reversed after 4 years. The toxicology of mercury, mechanisms of renal and systemic toxicities, and the various therapeutic measures for mercury poisoning are discussed. PMID:23439491

  17. Effect of cropping systems on heavy metal distribution and mercury fractionation in the Wanshan mining district, China: implications for environmental management.

    PubMed

    Wang, Jianxu; Feng, Xinbin; Anderson, Christopher W N; Qiu, Guangle; Bao, Zhengduo; Shang, Lihai

    2014-09-01

    The authors studied the concentration of heavy metals and mercury fractionation in contaminated soil in 2 agricultural land use systems (paddy rice and dry land) at the Wanshan mercury mine in China. The average concentrations of chromium, lead, copper, nickel, and zinc were generally lower in paddy rice soil relative to corn field soil. Soil under corn field production was slightly contaminated with lead (22-100 mg/kg), copper (31-64 mg/kg), and nickel (22-76 mg/kg) and moderately contaminated with zinc (112-635 mg/kg). In both soils, correlation of these metals with the titanium concentration in the soil indicates a geogenic origin for each metal (lead, r = 0.48; copper, r = 0.63; nickel, r = 0.47; zinc, r = 0.48). The mercury and antimony concentration in soil was high under both cropping systems, and future remediation efforts should consider the potential environmental risk presented by these metals. The concentration of bioavailable mercury in soil ranged from 0.3 ng/g to 11 ng/g across the 2 cropping systems. The majority of mercury (>80%) was associated with organic matter and the residual fraction. However, soil under paddy rice production exhibited a significantly lower concentration of Fe/Mn oxide-bound mercury than that under corn field production. This may be a function of the reduction of Fe/Mn oxides in the paddy rice soil, with the subsequent release of adsorbed metals to the soil solution. Sequential change from corn field to paddy rice production, as practiced in Wanshan, should therefore be avoided. Mercury adsorbed to Fe/Mn oxides in corn field soil potentially could be released into the soil solution and be made available for biomethylation under the flooded water management conditions of a rice paddy. PMID:24924832

  18. A Metal-Organic Framework/DNA Hybrid System as a Novel Fluorescent Biosensor for Mercury(II) Ion Detection.

    PubMed

    Wu, Lan-Lan; Wang, Zhuo; Zhao, Shu-Na; Meng, Xing; Song, Xue-Zhi; Feng, Jing; Song, Shu-Yan; Zhang, Hong-Jie

    2016-01-11

    Mercury(II) ions have emerged as a widespread environmental hazard in recent decades. Despite different kinds of detection methods reported to sense Hg(2+) , it still remains a challenging task to develop new sensing molecules to replenish the fluorescence-based apparatus for Hg(2+) detection. This communication demonstrates a novel fluorescent sensor using UiO-66-NH2 and a T-rich FAM-labeled ssDNA as a hybrid system to detect Hg(2+) sensitively and selectively. To the best of our knowledge, it has rarely been reported that a MOF is utilized as the biosensing platform for Hg(2+) assay. PMID:26555340

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

    SciTech Connect

    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

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

    NASA Astrophysics Data System (ADS)

    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

  1. Diagnostic system design for the Ion Auxiliary Propulsion System /IAPS/ - Flight test of two 8 cm mercury ion thrusters

    NASA Technical Reports Server (NTRS)

    Hurst, E. B.; Thomas, G. Z.

    1981-01-01

    The experimental design of a Diagnostic Subsystem (DSS) as part of an Ion Auxiliary Propulsion System (IAPS) to be flown on P80-1 spacecraft in May 1983, is discussed. The DSS is composed of several detectors measuring thruster efflux, material deposition and spacecraft potential relative to the local space plasma in the vicinity of two 8 cm mercury ion thrusters. The detectors consist of two QCM units measuring frequency in the range of two to 65 KHz. Nine solar cell arrays have the capability of measuring current and voltage from 0-600 mA and 0-0.9 V. Seven ion collectors can measure ion currents with bias voltages of 0, 25, 55 and 96 V. The potential probe can measure current at 16 different commandible levels varying from one to 5 K microamperes within a voltage range of -25 to 175 V. The analysis of the ground-based data indicates that the hardware is qualified for flight, with the detectors and electronic units having passed all functional and environmental tests. Block diagrams are given and the functional parameters of the different design configurations are described.

  2. Phytoremediation of Ionic and Methyl Mercury Pollution

    SciTech Connect

    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.

  3. Target area chamber system design for the National Ignition Facility

    SciTech Connect

    Wavrik, R.; Boyes, J.; Olson, C.; Dempsey, F.; Garcia, R.; Karpenko, V.; Anderson, A.; Tobin, M.; Latkowski, J.

    1994-06-01

    The National Ignition Facility (NIF) is a proposed Department of Energy facility which will contribute to the resolution of important Defense Program and inertial fusion energy issues for energy production in the future. The NIF will consist of a laser system with 192 independent beamlets transported to a target chamber. The target chamber is a multi-purpose structure that provides the interface between the target and the laser optics. The chamber must be capable of achieving moderate vacuum levels in reasonable times; it must remain dimensionally stable within micron tolerances, provide support for the optics, diagnostics, and target positioner; it must minimize the debris from the x-ray and laser light environments; and it must be capable of supporting external neutron shielding. The chamber must also be fabricated from a low activation material. The fusion reaction in the target gives off neutrons, x-ray and gamma rays. The x-rays and gamma rays interact with the interior of the target chamber wall while neutrons penetrate the wall. In order to minimize the neutron activation of components outside the target chamber and to absorb gammas emitted from the activated chamber, shielding will be placed immediately outside the chamber. The target chamber contains the target positioner. The target positioner moves the target from outside the chamber to the center of the chamber and positions the target at the focal spot of the laser beams. The target positioner must be survivable in a harsh radioactive environment. The materials used must be low activation and have a high stiffness to weight ratio to maintain target stability. This paper describes the conceptual design of the target chamber, target postioner, and shielding for the NIF.

  4. System Upgrades: The Ever Moving Target.

    ERIC Educational Resources Information Center

    Kaplan, Denise

    1989-01-01

    Discusses the need for system upgrades of automated library systems in order to support ongoing software releases; obtain new functional modules; satisfy new library requirements; conform to new industry standards; and utilize new technology. Guidelines are presented for deciding when to upgrade and implement changes in these areas. (11…

  5. Mercury speciation and transport via submarine groundwater discharge at a southern California coastal lagoon system

    USGS Publications Warehouse

    Ganguli, P.M.; Conaway, C.H.; Swarzenski, P.W.; Izbicki, J.A.; Flegal, A.R.

    2012-01-01

    We measured total mercury (Hg T) and monomethylmercury (MMHg) concentrations in coastal groundwater and seawater over a range of tidal conditions near Malibu Lagoon, California, and used 222Rn-derived estimates of submarine groundwater discharge (SGD) to assess the flux of mercury species to nearshore seawater. We infer a groundwater-seawater mixing scenario based on salinity and temperature trends and suggest that increased groundwater discharge to the ocean during low tide transported mercury offshore. Unfiltered Hg T (U-Hg T) concentrations in groundwater (2.2-5.9 pM) and seawater (3.3-5.2 pM) decreased during a falling tide, with groundwater U-Hg T concentrations typically lower than seawater concentrations. Despite the low Hg T in groundwater, bioaccumulative MMHg was produced in onshore sediment as evidenced by elevated MMHg concentrations in groundwater (0.2-1 pM) relative to seawater (???0.1 pM) throughout most of the tidal cycle. During low tide, groundwater appeared to transport MMHg to the coast, resulting in a 5-fold increase in seawater MMHg (from 0.1 to 0.5 pM). Similarly, filtered Hg T (F-Hg T) concentrations in seawater increased approximately 7-fold during low tide (from 0.5 to 3.6 pM). These elevated seawater F-Hg T concentrations exceeded those in filtered and unfiltered groundwater during low tide, but were similar to seawater U-Hg T concentrations, suggesting that enhanced SGD altered mercury partitioning and/or solubilization dynamics in coastal waters. Finally, we estimate that the SGD Hg T and MMHg fluxes to seawater were 0.41 and 0.15 nmol m -2 d -1, respectively - comparable in magnitude to atmospheric and benthic fluxes in similar environments. ?? 2012 American Chemical Society.

  6. Design of a liquid hydrogen target system

    NASA Astrophysics Data System (ADS)

    Komisarcik, K.; Meyer, H. O.; Bertuccio, T.; Manwaring, W.; Smith, W.

    1986-08-01

    An internal liquid hydrogen target is described for use with intermediate energy light ion beams. As a result, certain safety features are required to prevent a possible hydrogen explosion within the beamline or cyclotron. These safety features include an acoustical delay line which slows the hydrogen gas shock wave and a fast closing valve which shuts before any large volume of escaping gas reaches it. Other safety devices which reduce the chances of cell breakage and quickly shut off various ignition sources are discussed. Also described is a device involving a variable heat load which is coupled directly to the cryocondenser and is used to continually monitor and stabilize the pressure and temperature of the liquid hydrogen.

  7. Fish consumption and hair mercury levels in women of childbearing age, Martin County, Florida.

    PubMed

    Nair, Anil; Jordan, Melissa; Watkins, Sharon; Washam, Robert; DuClos, Chris; Jones, Serena; Palcic, Jason; Pawlowicz, Marek; Blackmore, Carina

    2014-12-01

    The health effects of mercury in humans are mostly on the developing nervous system. Pregnant women and women who are breastfeeding must be targeted in order to decrease mercury exposure to the populations at highest risk-infants, unborn fetuses, and young children. This purpose of this study is to understand the demographics of fish-consumption patterns among women of childbearing age (including pregnant women) in Martin County, Florida, and to analyze the associations of mercury levels in participants' hair with socio-demographic variables in order to better design prevention messages and campaigns. Mercury concentrations in hair samples of 408 women ages 18-49 were assessed. Data on demographic factors, pregnancy status, fish consumption, and awareness of fish advisories were collected during personal interviews. Data were analyzed using descriptive statistics and multivariate logistic regression. The geometric and arithmetic means of hair mercury concentration were 0.371 and 0.676 µg/g of hair. One-fourth of the respondents had a concentration ≥1 µg/g of hair. Consuming a higher number of fish meals per month, consumption of commercially purchased or locally caught fish higher in mercury, White race and income ≥$75,000 were positively associated with the likelihood of having higher hair mercury levels. This study confirms the existence of a higher overall mean hair mercury level and a higher percentage of women with ≥1 µg/g hair mercury level than those reported at the national level and in other regional studies. This suggests the need for region-specific fish consumption advisories to minimize mercury exposure in humans. PMID:24807406

  8. Detection of vapor phase mercury species by laser fluorescence methods

    NASA Astrophysics Data System (ADS)

    Tong, Xiaomei

    Several mercury species emissions have been identified in off-gases from industrial processes. At present, there is no commercial continuous emission monitoring (CEM) technique or instrumentation to reliably monitor volatile mercury species emissions from industrial stacks. Conventional measurement methods, such as cold vapor trap based techniques for elemental mercury, have difficulty in achieving both high sensitivity and the fast time resolution required for real-time monitoring. This doctoral research work gives a systematic study of potential methods for real-time trace detection of volatile elemental mercury and mercury compounds in industrial stack gases. It is based on laser-induced fluorescence techniques; photofragment fluorescence spectroscopy for detection of volatile mercury compounds, and resonance fluorescence for detection of elemental mercury. The capabilities and limitations of these detection techniques are investigated in this dissertation. Detection of mercury compounds is a challenge since they are non-fluorescent. With photofragment fluorescence spectroscopy, target compound concentrations are related to the fluorescence intensity from an excited fragment. In this doctoral research work, low concentrations of mercuric bromide vapor in an atmospheric pressure flow cell are irradiated by a focused laser beam at 222nm. Photofragment fluorescence is monitored at 253.7nm. Two detection schemes, Charge Coupled Device (CCD) and photomultiplier tube (PMT), are applied for the measurement of photofragment fluorescence. The performances of these two systems are compared in the dissertation. A supersonic jet is combined with resonance fluorescence for detection of elemental mercury vapor. With test gas expanded into a vacuum, fluorescence quenching and spectral broadening are reduced. In the experiment, the gas jet is crossed with a laser beam at 253.7nm to excite atomic fluorescence, which is distinguished from the elastic background by time gating

  9. A three-stage system to remove mercury and dioxins in flue gases.

    PubMed

    Hylander, Lars D; Sollenberg, Hans; Westas, Håkan

    2003-03-20

    Mercury (Hg) from combustion of fossil fuels and waste is the dominant source of anthropogenic Hg emissions, globally amounting to more than 1500 t Hgyear(-1). These emissions must decrease substantially in order to counteract increasing environmental levels of Hg and reduce future toxic effects. Uppsala Energi AB, nowadays (May, 2002) Vattenfall Värme Uppsala AB, an energy company in Uppsala, Sweden, has invested in equipments for air and water pollution control of their three waste fired steam boilers. The flue gases are cleaned in three stages in series to meet the strict Swedish regulation. Electrostatic precipitators remove most dust in the first stage, wet scrubbers remove most water-soluble gases, and in the last stage a Filsorption unit removes most remaining impurities in particulate as well as gaseous form. The Filsorption process includes additives injection, sorption, and chemical reaction in a reactor and filtration with a fabric filter. The aim with this article is to evaluate the efficiency of the system to recover Hg in flue gases from boilers in routine operation. Flue gases, ashes, and water were sampled yearly for 21 years and analysed for Hg, dioxin, and other potential contaminants received at waste incineration. The results clearly demonstrate the decreasing use of Hg in society the last two decades as influenced by governmental policy regarding Hg. The results also indicate that the equipment efficiently removed Hg and dioxins from the flue gases to a final concentration of approximately 3.5 microg Hgm(-3) n and 0.01 ng dioxinsm(-3) n, corresponding to more than 97 and 99.9% reduction of Hg and dioxins, respectively, by cleaning in three stages. The electrostatic precipitators and Filsorption stages alone, with the scrubber in bypass, removed 90% of Hg in flue gases. Using the scrubber is motivated to remove acid components and additional Hg, but call for water separated after the condensers to be neutralised and cleaned, so that less than 5

  10. Mercury capture by aerosol transformation in combustion environments. Appendix 5

    SciTech Connect

    1997-02-01

    Aerosol transformation of elemental mercury by oxidizing mercury in the air is investigated in this study by varying temperature and residence time. The experimental results show that mercury oxidation is not important at the temperature range and time scale studied. The rate of mercury oxidation is too slow that the capture of mercury vapor by transforming it into mercury oxide in aerosol phase is not practical in real systems. Studies are needed for alternative approaches to capture mercury vapor such as the use of sorbent materials.

  11. Mercury radar speckle dynamics

    NASA Astrophysics Data System (ADS)

    Holin, Igor V.

    2010-06-01

    Current data reveal that Mercury is a dynamic system with a core which has not yet solidified completely and is at least partially decoupled from the mantle. Radar speckle displacement experiments have demonstrated that the accuracy in spin-dynamics determination for Earth-like planets can approach 10 -5. The extended analysis of space-time correlation properties of radar echoes shows that the behavior of speckles does not prevent estimation of Mercury's instantaneous spin-vector components to accuracy of a few parts in 10 7. This limit can be reached with more powerful radar facilities and leads to constraining the interior in more detail from effects of spin dynamics, e.g., from observation of the core-mantle interplay through high precision monitoring of the 88-day spin-variation of Mercury's crust.

  12. A Fast MEANSHIFT Algorithm-Based Target Tracking System

    PubMed Central

    Sun, Jian

    2012-01-01

    Tracking moving targets in complex scenes using an active video camera is a challenging task. Tracking accuracy and efficiency are two key yet generally incompatible aspects of a Target Tracking System (TTS). A compromise scheme will be studied in this paper. A fast mean-shift-based Target Tracking scheme is designed and realized, which is robust to partial occlusion and changes in object appearance. The physical simulation shows that the image signal processing speed is >50 frame/s. PMID:22969397

  13. Mosaic Postcards from Mercury

    NASA Astrophysics Data System (ADS)

    Hallau, K. G.; Chapman, C. R.; Edmonds, J.; Goldstein, J.; Hirshon, B.; Solomon, S. C.; Vanhala, H.; Weir, H. M.; Messenger Education; Public Outreach Team

    2010-12-01

    On its journey to become the first spacecraft to orbit Mercury, NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft has followed a trajectory that included three flybys of the innermost planet. During the flybys, images captured by the Mercury Dual Imaging System revealed parts of the planet’s surface never before seen at close range, as well as high-resolution views of craters, crater rays, scarps, faults, and volcanic vents and flows. To help students and teachers better understand this revealing new look at Mercury, the MESSENGER Education and Public Outreach team will share these high-resolution images of Mercury's surface throughout the upcoming Year of the Solar System. By means of an intriguing format that mimics methods used by the MESSENGER team, a series of images printed at large postcard size will each highlight a small "slice" of Mercury, such as a crater or fault. The individual cards can then be pieced together, puzzle-style, on a poster-sized grid to reveal a larger mosaic view of the planet. Each card contains engaging text, the URL for an accompanying website, and coordinates for that region of the planet, helping students understand scientific concepts related to and revealed by MESSENGER's journey. The first set of cards will feature scarps, volcanic plains, the topography of a crater and the composition of its interior units, rayed craters, nested craters, and a deposit produced by explosive volcanic eruptions. Cards will be available for free on the accompanying website, distributed by MESSENGER Educator Fellows, or handed out at meetings, conferences, and workshops.

  14. Mercury-T: A new code to study tidally evolving multi-planet systems. Applications to Kepler-62

    NASA Astrophysics Data System (ADS)

    Bolmont, Emeline; Raymond, Sean N.; Leconte, Jeremy; Hersant, Franck; Correia, Alexandre C. M.

    2015-11-01

    A large proportion of observed planetary systems contain several planets in a compact orbital configuration, and often harbor at least one close-in object. These systems are then most likely tidally evolving. We investigate how the effects of planet-planet interactions influence the tidal evolution of planets. We introduce for that purpose a new open-source addition to the MercuryN-body code, Mercury-T, which takes into account tides, general relativity and the effect of rotation-induced flattening in order to simulate the dynamical and tidal evolution of multi-planet systems. It uses a standard equilibrium tidal model, the constant time lag model. Besides, the evolution of the radius of several host bodies has been implemented (brown dwarfs, M-dwarfs of mass 0.1 M⊙, Sun-like stars, Jupiter). We validate the new code by comparing its output for one-planet systems to the secular equations results. We find that this code does respect the conservation of total angular momentum. We applied this new tool to the planetary system Kepler-62. We find that tides influence the stability of the system in some cases. We also show that while the four inner planets of the systems are likely to have slow rotation rates and small obliquities, the fifth planet could have a fast rotation rate and a high obliquity. This means that the two habitable zone planets of this system, Kepler-62e ad f are likely to have very different climate features, and this of course would influence their potential at hosting surface liquid water. The code is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/583/A116

  15. Design and performance of liquid hydrogen target systems for the Fermilab Fixed Target Program

    SciTech Connect

    Allspah, D.; Danes, J.; Peifer, J.; Stanek, R.

    1991-07-01

    The Fermilab 1990--1991 Fixed Target Program featured six experiments utilizing liquid hydrogen or liquid deuterium targets as part of their apparatus. Each design was optimized to the criteria of the experiment, resulting in variations of material selection, methods of refrigeration and secondary containment. Collectively, the targets were run for a total of 14,184 hours with an average operational efficiency of 97.6%. The safe and reliable operation of these targets was complemented by an increased degree of documentation and component testing. This operation was also aided by several key upgrades. All the systems were designed and fabricated under a set of written guidelines that blend analytical calculations and empirical guidance drawn from over twenty years of target fabrication experience. 3 refs., 4 tabs.

  16. Demonstration of the ULTOR target recognition and tracking system

    NASA Astrophysics Data System (ADS)

    Hartman, Richard L.; Farr, Keith B.

    2003-08-01

    Advanced Optical Systems has developed the world's smallest and lowest cost, fully functional target recognition and tracking system. The heart of the ULTOR target recognition and tracking system is an optical correlator. The system includes real-time preprocessing, large filter stores, filter management logic, correlation detection and thresholding, correlation tracking, and data output. It is self contained, receiving operational commands as an Internet appliance. We will present a demonstration of some of the capabilities of the system using live video signals and real target models. The ULTOR system has wide application in both military and commercial settings. The Navy is considering use of the ULTOR system in several programs, including missile systems and unmanned aerial vehicles.

  17. Low-flying target position finding with a seismic system

    NASA Astrophysics Data System (ADS)

    Cechak, Jaroslav; Hubacek, Petr; Vesely, Jiri

    2009-06-01

    The development of new sensor systems able to detect, identify and find position of the targets equipped with STEALTH technology began early in 1990s. Some of the sensor systems utilise acoustic, magnetic, seismic and/or other physical effects of target activity. A reason motivating the development of new sensor systems based on other than radar or optical principal of operation in detecting targets is that the systems usually emit no electromagnetic energy during operation. Thanks to their passive principle they provide the users with the advantages of hidden positioning and difficult discovery with reconnaissance tools. Therefore, some of the new UGS systems also allow detecting low-flying targets, such as helicopters, propeller or jet aircraft, etc., in the detection range of up to several kilometres. The information of flight direction is usually estimated and deduced from spatiotemporal sequence detections by multiple interlinked UGS systems. The submitted paper analyses low-flying target position finding principle on Time Direction Of Arrival (TDOA) basis. It presents the qualities of found UGS arrangement topologies and the characteristics of the unambiguous position determination of low-flying targets. It also contains mathematical description of signal digital processing intended to find low-flying target's position. The processed results are presented in table and diagram forms created in Matlab mathematical environment. All the presented detection and identification results were obtained from real recorded signals.

  18. Momument at Pad 14 honoring Project Mercury

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Momument at Pad 14 honoring Project Mercury. The Arabic number 7 represents the seven original astronauts. The other figure is the astronomical symbol of the Planet Mercury. In background is the Gemini 12 Agena Target Docking Vehicle atop its Atlas launch vehicle at Cape Kennedy, Florida.

  19. [Effect of Soil and Dominant Plants on Mercury Speciation in Soil and Water System of Water-Level-Fluctuation Zone in the Three Gorges Area].

    PubMed

    Liang, Li; Wang, Yong-min; Zhang, Cheng; Yu, Ya-wei; An, Si-wei; Wang, Ding-yong

    2016-03-15

    Plentiful plants in the water-level-fluctuation-zone (WLFZ) of Three Gorges Reservoir ( TGR) grow vigorously during the non-flooded period, especially the herbaceous ones. Then, the WLFZ is submerged gradually from the end of September. Soil-plant system that under a long time flooded condition may change the form of mercury, thus resulting in a secondary pollution of the water environment in TGR. To understand the characteristics of mercury species in soils and water after submerged, four kinds of typical plants from TGR were tested in the lab under submerged condition. The results indicated that the plants could promote the formation of soil methylmercury ( MeHg) , and had a significant effect on the different forms of mercury concentrations of the overlying water during inundation. Cynodon dactylon as the dominant species in WLFZ, because of its higher content of total mercury ( THg ) and methylmercury, the effect on MeHg and the other forms of mercury in the soil and the overlying water system was obvious. After 90 days, the soil MeHg level was the highest in Cynodon dactylon & soil & water treatment (B1) [(1,135.86 ± 113.84) ng · kg⁻¹]. It was approximately 2 times less than that of the soil MeHg in soil & water treatment (CK2) . The variation characteristics of total mercury (THg), reactive mercury (RHg) , dissolved mercury (DHg), total methylmercury (TMeHg) and dissolved methylmercury (DMeHg) of overlying water all showed a parabolic shape with a peak skewed to the left, and the peak was reached on the 30th day. Meanwhile, TMeHg, THg and DHg in B1 treatment were the highest, which were (2.88 ± 0.06), (40.29 · 2.42) and (35.51 · 3.77) ng · L⁻¹ respectively, and TMeHg and THg in the overlying water were mainly in the form of dissolved state. Therefore, it could be inferred that the water consumption of the Three Gorges reservoir would increase the mercury pollution load of the reservoir. PMID:27337887

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

    NASA Astrophysics Data System (ADS)

    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

  1. Mercury Contamination

    PubMed Central

    Thompson, Marcella R.

    2013-01-01

    IN BRIEF A residential elemental mercury contamination incident in Rhode Island resulted in the evacuation of an entire apartment complex. To develop recommendations for improved response, all response-related documents were examined; personnel involved in the response were interviewed; policies and procedures were reviewed; and environmental monitoring data were compiled from specific phases of the response for analysis of effect. A significant challenge of responding to residential elemental mercury contamination lies in communicating risk to residents affected py a HazMat spill. An ongoing, open and honest dialogue is emphasized where concerns of the public are heard and addressed, particularly when establishing and/or modifying policies and procedures for responding to residential elemental mercury contamination. PMID:23436951

  2. Polarization effects on hard target calibration of lidar systems

    NASA Technical Reports Server (NTRS)

    Kavaya, Michael J.

    1987-01-01

    The theory of hard target calibration of lidar backscatter data, including laboratory measurements of the pertinent target reflectance parameters, is extended to include the effects of polarization of the transmitted and received laser radiation. The bidirectional reflectance-distribution function model of reflectance is expanded to a 4 x 4 matrix allowing Mueller matrix and Stokes vector calculus to be employed. Target reflectance parameters for calibration of lidar backscatter data are derived for various lidar system polarization configurations from integrating sphere and monostatic reflectometer measurements. It is found that correct modeling of polarization effects is mandatory for accurate calibration of hard target reflectance parameters and, therefore, for accurate calibration of lidar backscatter data.

  3. Activation of theMercury Laser System: A Diode-Pumped Solid-State Laser Driver for Inertial Fusion

    SciTech Connect

    Bayramian, A J; Beach, R J; Bibeau, C; Ebbers, C A; Freitas, B L; Kanz, V K; Payne, S A; Schaffers, K I; Skulina, K M; Smith, L K; Tassano, J B

    2001-09-10

    Initial measurements are reported for the Mercury laser system, a scalable driver for rep-rated inertial fusion energy. The performance goals include 10% electrical efficiency at 10 Hz and 100 J with a 2-10 ns pulse length. We report on the first Yb:S-FAP crystals grown to sufficient size for fabricating full size (4 x 6 cm) amplifier slabs. The first of four 160 kW (peak power) diode arrays and pump delivery systems were completed and tested with the following results: 5.5% power droop over a 0.75 ms pulse, 3.95 nm spectral linewidth, far field divergence of 14.0 mrad and 149.5 mrad in the microlensed and unmicrolensed directions respectively, and 83% optical-to-optical transfer efficiency through the pump delivery system.

  4. Engineering of the Magnetized Target Fusion Propulsion System

    NASA Technical Reports Server (NTRS)

    Statham, G.; White, S.; Adams, R. B.; Thio, Y. C. F.; Santarius, J.; Alexander, R.; Chapman, J.; Fincher, S.; Philips, A.; Polsgrove, T.

    2003-01-01

    Engineering details are presented for a magnetized target fusion (MTF) propulsion system designed to support crewed missions to the outer solar system. Basic operation of an MTF propulsion system is introduced. Structural, thermal, radiation-management and electrical design details are presented. The propellant storage and supply system design is also presented. A propulsion system mass estimate and associated performance figures are given. The advantages of helium-3 as a fusion fuel for an advanced MTF system are discussed.

  5. FINAL REPORT ON THE AQUATIC MERCURY ASSESSMENT STUDY

    SciTech Connect

    Halverson, N

    2008-09-30

    In February 2000, the United States Environmental Protection Agency (EPA) Region 4 issued a proposed Total Maximum Daily Load (TMDL) for total mercury in the middle and lower Savannah River. The initial TMDL, which would have imposed a 1 ng/l mercury limit for discharges to the middle/lower Savannah River, was revised to 2.8 ng/l in the final TMDL released in February 2001. The TMDL was intended to protect people from the consumption of contaminated fish, which is the major route of mercury exposure to humans. The most bioaccumulative form of mercury is methylmercury, which is produced in aquatic environments by the action of microorganisms on inorganic mercury. Because of the environmental and economic significance of the mercury discharge limits that would have been imposed by the TMDL, the Savannah River Site (SRS) initiated several studies concerning: (1) mercury in SRS discharges, SRS streams and the Savannah River, (2) mercury bioaccumulation factors for Savannah River fish, (3) the use of clams to monitor the influence of mercury from tributary streams on biota in the Savannah River, and (4) mercury in rainwater falling on the SRS. The results of these studies are presented in detail in this report. The first study documented the occurrence, distribution and variation of total and methylmercury at SRS industrial outfalls, principal SRS streams and the Savannah River where it forms the border with the SRS. All of the analyses were performed using the EPA Method 1630/31 ultra low-level and contaminant-free techniques for measuring total and methylmercury. Total mercury at National Pollutant Discharge Elimination System (NPDES) outfalls ranged from 0.31-604 ng/l with a mean of 8.71 ng/l. Mercury-contaminated groundwater was the source for outfalls with significantly elevated mercury concentrations. Total mercury in SRS streams ranged from 0.95-15.7 ng/l. Mean total mercury levels in the streams varied from 2.39 ng/l in Pen Branch to 5.26 ng/l in Tims Branch

  6. NMR structural studies reveal a novel protein fold for MerB, the organomercurial lyase involved in the bacterial mercury resistance system.

    PubMed

    Di Lello, Paola; Benison, Gregory C; Valafar, Homayoun; Pitts, Keith E; Summers, Anne O; Legault, Pascale; Omichinski, James G

    2004-07-01

    Mercury resistant bacteria have developed a system of two enzymes (MerA and MerB), which allows them to efficiently detoxify both ionic and organomercurial compounds. The organomercurial lyase (MerB) catalyzes the protonolysis of the carbon-mercury bond resulting in the formation of ionic mercury and a reduced hydrocarbon. The ionic mercury [Hg(II)] is subsequently reduced to the less reactive elemental mercury [Hg(0)] by a specific mercuric reductase (MerA). To better understand MerB's unique enzymatic activity, we used nuclear magnetic resonance (NMR) spectroscopy to determine the structure of the free enzyme. MerB is characterized by a novel protein fold consisting of three noninteracting antiparallel beta-sheets surrounded by six alpha-helices. By comparing the NMR data of free MerB and the MerB/Hg/DTT complex, we identified a set of residues that likely define a Hg/DTT binding site. These residues cluster around two cysteines (C(96) and C(159)) that are crucial to MerB's catalytic activity. A detailed analysis of the structure revealed the presence of an extensive hydrophobic groove adjacent to this Hg/DTT binding site. This extensive hydrophobic groove has the potential to interact with the hydrocarbon moiety of a wide variety of substrates and may explain the broad substrate specificity of MerB. PMID:15222745

  7. Mercury emission from crematories in Japan

    NASA Astrophysics Data System (ADS)

    Takaoka, M.; Oshita, K.; Takeda, N.; Morisawa, S.

    2010-04-01

    Anthropogenic sources of mercury emissions have a significant impact on global pollution. Therefore, finding uncharacterised sources and assessing the emissions from these sources are important. However, limited data are available worldwide on mercury emissions from crematories. In Japan, 99.9% of dead bodies are cremated, which is the highest percentage in the world, and more than 1600 crematories are in operation. We thus focused on emissions from crematories in Japan. The number of targeted facilities was seven, and we used continuous emission monitoring to measure the mercury concentrations and investigate mercury behaviour. The total mercury concentrations in stack gases were a few μg/Nm3 (normal cubic meters). Considering the time profile of mercury and its species in cremations, the findings confirmed that the mercury in stack gas originated from dental amalgam. The amount of mercury emissions was calculated using the total concentration and gas flow rate. Furthermore, the annual amount of mercury emission from crematories in Japan was estimated by using the total number of corpses. The emission amount was considerably lower than that estimated in the United Kingdom. From statistical analyses on population demographics and measurements, future total emissions from crematories were also predicted. As a result, the amount of mercury emitted by crematories will likely increase by 2.6-fold from 2007 to 2037.

  8. Mercury emission from crematories in Japan

    NASA Astrophysics Data System (ADS)

    Takaoka, M.; Oshita, K.; Takeda, N.; Morisawa, S.

    2009-12-01

    Anthropogenic sources of mercury emissions have a significant impact on global pollution. Therefore, finding uncharacterised sources and assessing the emissions from these sources are important. However, limited data are available worldwide on mercury emissions from crematories. In Japan, 99.9% of dead bodies are cremated, which is the highest percentage in the world, and more than 1600 crematories are in operation. We thus focused on emissions from crematories in Japan. The number of targeted facilities was seven, and we used continuous emission monitoring to measure the mercury concentrations and investigate mercury behaviour. The total mercury concentrations in stack gases were a few μg/Nm3 (normal cubic meters). Considering the time profile of mercury and its species in cremations, the findings confirmed that the mercury in stack gas originated from dental amalgam. The amount of mercury emissions was calculated using the total concentration and gas flow rate. Furthermore, the annual amount of mercury emission from crematories in Japan was estimated by using the total number of corpses. The emission amount was considerably lower than that estimated in the UK. From statistical analyses on population demographics and measurements, future total emissions from crematories were also predicted. As a result, the amount of mercury emitted by crematories will likely increase by 2.6-fold from 2007 to 2037.

  9. Mercury Specie and Multi-Pollutant Control

    SciTech Connect

    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.

  10. Treat to target in systemic lupus erythematosus: a commentary.

    PubMed

    Ugarte-Gil, Manuel F; Burgos, Paula I; Alarcón, Graciela S

    2016-08-01

    Treat to target (T2T) strategies have proved to be useful in several chronic disorders, including Rheumatoid Arthritis. In systemic lupus erythematosus (SLE), T2T strategy has been proposed in order to control disease activity, improve health-related quality of life, and reduce morbidity and mortality. Remission would be the main target, but a low disease activity state (LDAS) could be an acceptable alternative. However, due to SLE protean manifestations, the operational definitions of both remission and LDAS are still in progress. The definitions of these targets, remission and LDAS, should include a validated disease activity index, the treatments allowed, and the minimum length of time the target should be maintained. Furthermore, achieving these targets should result in better disease outcomes such as reducing damage accrual. This review addresses the current state regarding these possible targets in SLE and the impact of achieving them in intermediate and long-term outcomes of this disease. PMID:27406378

  11. Development of a higher power cooling system for lithium targets.

    PubMed

    Phoenix, B; Green, S; Scott, M C; Bennett, J R J; Edgecock, T R

    2015-12-01

    The accelerator based Boron Neutron Capture Therapy beam at the University of Birmingham is based around a solid thick lithium target cooled by heavy water. Significant upgrades to Birmingham's Dynamitron accelerator are planned prior to commencing a clinical trial. These upgrades will result in an increase in maximum achievable beam current to at least 3 mA. Various upgrades to the target cooling system to cope with this increased power have been investigated. Tests of a phase change coolant known as "binary ice" have been carried out using an induction heater to provide a comparable power input to the Dynamitron beam. The experimental data shows no improvement over chilled water in the submerged jet system, with both systems exhibiting the same heat input to target temperature relation for a given flow rate. The relationship between the cooling circuit pumping rate and the target temperature in the submerged jet system has also been tested. PMID:26254970

  12. Multiple operating system rotation environment moving target defense

    DOEpatents

    Evans, Nathaniel; Thompson, Michael

    2016-03-22

    Systems and methods for providing a multiple operating system rotation environment ("MORE") moving target defense ("MTD") computing system are described. The MORE-MTD system provides enhanced computer system security through a rotation of multiple operating systems. The MORE-MTD system increases attacker uncertainty, increases the cost of attacking the system, reduces the likelihood of an attacker locating a vulnerability, and reduces the exposure time of any located vulnerability. The MORE-MTD environment is effectuated by rotation of the operating systems at a given interval. The rotating operating systems create a consistently changing attack surface for remote attackers.

  13. X-ray fluorescence mapping of mercury on suspended mineral particles and diatoms in a contaminated freshwater system

    DOE PAGESBeta

    Gu, B.; Mishra, B.; Miller, C.; Wang, W.; Lai, B.; Brooks, S. C.; Kemner, K. M.; Liang, L.

    2014-09-30

    Mercury (Hg) bioavailability and geochemical cycling is affected by its partitioning between the aqueous and particulate phases. We applied a synchrotron-based X-ray fluorescence (XRF) microprobe to visualize and quantify directly the spatial localization of Hg and its correlations with other elements of interest on suspended particles from a Hg-contaminated freshwater system. Up to 175 μg g−1 Hg is found on suspended particles, but less than 0.01% is in the form of methylmercury. Mercury is heterogeneously distributed among phytoplankton (e.g., diatoms) and mineral particles that are rich in iron oxides and natural organic matter (NOM). The diatom-bound Hg is mostly foundmore » on outer surfaces of the cells, suggesting passive sorption of Hg on diatoms. Our results indicate that localized sorption of Hg onto suspended particles, including diatoms and NOM-coated oxide minerals, may play an important role in affecting the partitioning, reactivity, and biogeochemical cycling of Hg in natural aquatic environments.« less

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

    SciTech Connect

    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

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

    SciTech Connect

    Zamecnik, J.; Choi, A.

    2009-03-25

    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{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

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

    SciTech Connect

    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

  17. Spatiotemporal gene expression targeting with the TARGET and gene-switch systems in Drosophila.

    PubMed

    McGuire, Sean E; Mao, Zhengmei; Davis, Ronald L

    2004-02-17

    Targeted gene expression has become a standard technique for the study of biological questions in Drosophila. Until recently, transgene expression could be targeted in the dimension of either time or space, but not both. Several new systems have recently been developed to direct transgene expression simultaneously in both time and space. We describe here two such systems that we developed in our laboratory. The first system provides a general method for temporal and regional gene expression targeting (TARGET) with the conventional GAL4-upstream activator sequence (UAS) system and a temperature-sensitive GAL80 molecule, which represses GAL4 transcriptional activity at permissive temperatures. The second system, termed Gene-Switch, is based on a GAL4-progesterone receptor chimera that is hormone-inducible. We have used both systems for simultaneous spatial and temporal rescue of memory dysfunction in the rutabaga (rut) memory mutant of Drosophila. In this protocol, we provide guidelines for the use of these two novel systems, which should have general utility in studying Drosophila biology and in using the fly as a model for human disease. PMID:14970377

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

    EPA Science Inventory

    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, ...

  19. A CRITICAL ASSESSMENT OF ELEMENTAL MERCURY AIR/WATER EXCHANGE PARTNERS

    EPA Science Inventory

    Although evasion of elemental mercury from aquatic systems can significantly deplete net mercury accumulation resulting from atmospheric deposition, the current ability to model elemental mercury air/water exchange is limited by uncertainties in our understanding of all gaseous a...

  20. Targeted Delivery Systems for Molecular Therapy in Skeletal Disorders

    PubMed Central

    Dang, Lei; Liu, Jin; Li, Fangfei; Wang, Luyao; Li, Defang; Guo, Baosheng; He, Xiaojuan; Jiang, Feng; Liang, Chao; Liu, Biao; Badshah, Shaikh Atik; He, Bing; Lu, Jun; Lu, Cheng; Lu, Aiping; Zhang, Ge

    2016-01-01

    Abnormalities in the integral components of bone, including bone matrix, bone mineral and bone cells, give rise to complex disturbances of skeletal development, growth and homeostasis. Non-specific drug delivery using high-dose systemic administration may decrease therapeutic efficacy of drugs and increase the risk of toxic effects in non-skeletal tissues, which remain clinical challenges in the treatment of skeletal disorders. Thus, targeted delivery systems are urgently needed to achieve higher drug delivery efficiency, improve therapeutic efficacy in the targeted cells/tissues, and minimize toxicities in non-targeted cells/tissues. In this review, we summarize recent progress in the application of different targeting moieties and nanoparticles for targeted drug delivery in skeletal disorders, and also discuss the advantages, challenges and perspectives in their clinical translation. PMID:27011176

  1. Alzheimer's Disease: Targeting the Cholinergic System

    PubMed Central

    Ferreira-Vieira, Talita H.; Guimaraes, Isabella M.; Silva, Flavia R.; Ribeiro, Fabiola M.

    2016-01-01

    Acetylcholine (ACh) has a crucial role in the peripheral and central nervous systems. The enzyme choline acetyltransferase (ChAT) is responsible for synthesizing ACh from acetyl-CoA and choline in the cytoplasm and the vesicular acetylcholine transporter (VAChT) uptakes the neurotransmitter into synaptic vesicles. Following depolarization, ACh undergoes exocytosis reaching the synaptic cleft, where it can bind its receptors, including muscarinic and nicotinic receptors. ACh present at the synaptic cleft is promptly hydrolyzed by the enzyme acetylcholinesterase (AChE), forming acetate and choline, which is recycled into the presynaptic nerve terminal by the high-affinity choline transporter (CHT1). Cholinergic neurons located in the basal forebrain, including the neurons that form the nucleus basalis of Meynert, are severely lost in Alzheimer’s disease (AD). AD is the most ordinary cause of dementia affecting 25 million people worldwide. The hallmarks of the disease are the accumulation of neurofibrillary tangles and amyloid plaques. However, there is no real correlation between levels of cortical plaques and AD-related cognitive impairment. Nevertheless, synaptic loss is the principal correlate of disease progression and loss of cholinergic neurons contributes to memory and attention deficits. Thus, drugs that act on the cholinergic system represent a promising option to treat AD patients. PMID:26813123

  2. Mercury toxicity and neurodegenerative effects.

    PubMed

    Carocci, Alessia; Rovito, Nicola; Sinicropi, Maria Stefania; Genchi, Giuseppe

    2014-01-01

    Mercury is among the most toxic heavy metals and has no known physiological role in humans. Three forms of mercury exist: elemental, inorganic and organic. Mercury has been used by man since ancient times. Among the earliest were the Chinese and Romans, who employed cinnabar (mercury sulfide) as a red dye in ink (Clarkson et al. 2007). Mercury has also been used to purify gold and silver minerals by forming amalgams. This is a hazardous practice, but is still widespread in Brazil's Amazon basin, in Laos and in Venezuela, where tens of thousands of miners are engaged in local mining activities to find and purify gold or silver. Mercury compounds were long used to treat syphilis and the element is still used as an antiseptic,as a medicinal preservative and as a fungicide. Dental amalgams, which contain about 50% mercury, have been used to repair dental caries in the U.S. since 1856.Mercury still exists in many common household products around the world.Examples are: thermometers, barometers, batteries, and light bulbs (Swain et al.2007). In small amounts, some organo mercury-compounds (e.g., ethylmercury tiosalicylate(thimerosal) and phenylmercury nitrate) are used as preservatives in some medicines and vaccines (Ballet al. 2001).Each mercury form has its own toxicity profile. Exposure to Hg0 vapor and MeHg produce symptoms in CNS, whereas, the kidney is the target organ when exposures to the mono- and di-valent salts of mercury (Hg+ and Hg++, respectively)occur. Chronic exposure to inorganic mercury produces stomatitis, erethism and tremors. Chronic MeHg exposure induced symptoms similar to those observed in ALS, such as the early onset of hind limb weakness (Johnson and Atchison 2009).Among the organic mercury compounds, MeHg is the most biologically available and toxic (Scheuhammer et a!. 2007). MeHg is neurotoxic, reaching high levels of accumulation in the CNS; it can impair physiological function by disrupting endocrine glands (Tan et a!. 2009).The most

  3. Engineering of the Magnetized Target Fusion Propulsion System

    NASA Technical Reports Server (NTRS)

    Statham, G.; White, S.; Adams, R. B.; Thio, Y. C. F.; Santarius, J.; Alexander, R.; Fincher, S.; Polsgrove, T.; Chapman, J.; Philips, A.

    2002-01-01

    Engineering details are presented for a magnetized target fusion (MTF) propulsion system designed to support crewed missions to the outer solar system. Structural, thermal and radiation-management design details are presented. Propellant storage and supply options are also discussed and a propulsion system mass estimate is given.

  4. Characteristics of mercury cycling in the cement production process.

    PubMed

    Wang, Fengyang; Wang, Shuxiao; Zhang, Lei; Yang, Hai; Wu, Qingru; Hao, Jiming

    2016-01-25

    The mercury cycling caused by dust shuttling significantly increases the atmospheric emissions from cement production. A comprehensive understanding of this mercury cycling can promote the development of mercury emission control technologies. In this study, the characteristics of mercury cycling in the cement production process were first investigated. Furthermore, the mercury enrichment and effects of dust treatment were evaluated based on the field tests conducted in two Chinese cement plants. The mercury cycling between the kiln system and the raw mill system was the most important aspect and contributed 57-73% to the total amount of mercury emitted from the kiln system. Mercury emitted from the kiln system with flue gas was enriched as high as 3.4-8.8 times in the two tested plants compared to the amount of mercury in the raw materials and coal due to mercury cycling. The mercury enrichment can be significantly affected by the proportion of mercury cycled back to the kiln system. The effects of dust treatment were evaluated, and dust treatment can efficiently reduce approximately 31-70% of atmospheric mercury emissions in the two plants. The reduction proportion approximately linearly decreased with the proportion of mercury removed from the collected dust. PMID:26448491

  5. Real-time automatic target identification system for air-to-ground targeting

    NASA Astrophysics Data System (ADS)

    Nicholas, Mike; Wood, Jonathan; Nothard, Jo

    2005-10-01

    Future targeting systems, for manned or unmanned combat aircraft, aim to provide increased mission success and platform survivability by successfully detecting and identifying even difficult targets at very long ranges. One of the key enabling technologies for such systems is robust automatic target identification (ATI), operating on high resolution electro-optic sensor imagery. QinetiQ have developed a real time ATI processor which will be demonstrated with infrared imagery from the Wescam MX15 in airborne trials in summer 2005. This paper describes some of the novel ATI algorithms, the challenges overcome to port the ATI from the laboratory onto a real time system and offers an assessment of likely airborne performance based on analysis of synthetic image sequences.

  6. Systemically Administered, Target Organ-Specific Therapies for Regenerative Medicine

    PubMed Central

    Järvinen, Tero A. H.; May, Ulrike; Prince, Stuart

    2015-01-01

    Growth factors and other agents that could potentially enhance tissue regeneration have been identified, but their therapeutic value in clinical medicine has been limited for reasons such as difficulty to maintain bioactivity of locally applied therapeutics in the protease-rich environment of regenerating tissues. Although human diseases are treated with systemically administered drugs in general, all current efforts aimed at enhancing tissue repair with biological drugs have been based on their local application. The systemic administration of growth factors has been ruled out due to concerns about their safety. These concerns are warranted. In addition, only a small proportion of systemically administered drugs reach their intended target. Selective delivery of the drug to the target tissue and use of functional protein domains capable of penetrating cells and tissues could alleviate these problems in certain circumstances. We will present in this review a novel approach utilizing unique molecular fingerprints (“Zip/postal codes”) in the vasculature of regenerating tissues that allows target organ-specific delivery of systemically administered therapeutic molecules by affinity-based physical targeting (using peptides or antibodies as an “address tag”) to injured tissues undergoing repair. The desired outcome of targeted therapies is increased local accumulation and lower systemic concentration of the therapeutic payload. We believe that the physical targeting of systemically administered therapeutic molecules could be rapidly adapted in the field of regenerative medicine. PMID:26437400

  7. Hybrid-drive implosion system for ICF targets

    DOEpatents

    Mark, James W.

    1988-01-01

    Hybrid-drive implosion systems (20,40) for ICF targets (10,22,42) are described which permit a significant increase in target gain at fixed total driver energy. The ICF target is compressed in two phases, an initial compression phase and a final peak power phase, with each phase driven by a separate, optimized driver. The targets comprise a hollow spherical ablator (12) surroundingly disposed around fusion fuel (14). The ablator is first compressed to higher density by a laser system (24), or by an ion beam system (44), that in each case is optimized for this initial phase of compression of the target. Then, following compression of the ablator, energy is directly delivered into the compressed ablator by an ion beam driver system (30,48) that is optimized for this second phase of operation of the target. The fusion fuel (14) is driven, at high gain, to conditions wherein fusion reactions occur. This phase separation allows hydrodynamic efficiency and energy deposition uniformity to be individually optimized, thereby securing significant advantages in energy gain. In additional embodiments, the same or separate drivers supply energy for ICF target implosion.

  8. Hybrid-drive implosion system for ICF targets

    DOEpatents

    Mark, J.W.K.

    1987-10-14

    Hybrid-drive implosion systems for ICF targets are described which permit a significant increase in target gain at fixed total driver energy. The ICF target is compressed in two phases, an initial compression phase and a final peak power phase, with each phase driven by a separate, optimized driver. The targets comprise a hollow spherical ablator surroundingly disposed around fusion fuel. The ablator is first compressed to higher density by a laser system, or by an ion beam system, that in each case is optimized for this initial phase of compression of the target. Then, following compression of the ablator, energy is directly delivered into the compressed ablator by an ion beam driver system that is optimized for this second phase of operation of the target. The fusion fuel is driven, at high gain, to conditions wherein fusion reactions occur. This phase separation allows hydrodynamic efficiency and energy deposition uniformity to be individually optimized, thereby securing significant advantages in energy gain. In additional embodiments, the same or separate drivers supply energy for ICF target implosion. 3 figs.

  9. Hybrid-drive implosion system for ICF targets

    DOEpatents

    Mark, James W.

    1988-08-02

    Hybrid-drive implosion systems (20,40) for ICF targets (10,22,42) are described which permit a significant increase in target gain at fixed total driver energy. The ICF target is compressed in two phases, an initial compression phase and a final peak power phase, with each phase driven by a separate, optimized driver. The targets comprise a hollow spherical ablator (12) surroundingly disposed around fusion fuel (14). The ablator is first compressed to higher density by a laser system (24), or by an ion beam system (44), that in each case is optimized for this initial phase of compression of the target. Then, following compression of the ablator, energy is directly delivered into the compressed ablator by an ion beam driver system (30,48) that is optimized for this second phase of operation of the target. The fusion fuel (14) is driven, at high gain, to conditions wherein fusion reactions occur. This phase separation allows hydrodynamic efficiency and energy deposition uniformity to be individually optimized, thereby securing significant advantages in energy gain. In additional embodiments, the same or separate drivers supply energy for ICF target implosion.

  10. Mercury capture in bench-scale absorbers

    SciTech Connect

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

    1994-08-01

    This paper gives,a brief overview of research being conducted at Argonne National Laboratory on the capture of mercury by both dry sorbents and wet scrubbers. The emphasis in the research is on development of a better understanding of the key factors that control the capture of mercury. Future work is expected to utilize that information for the development of new or modified process concepts featuring enhanced mercury capture capabilities. The results and conclusions to date from the Argonne -research on dry sorbents can be summarized as follows: lime hydrates, either regular or high-surface-area, are `not effective in removing mercury; mercury removals are enhanced by the addition of activated carbon; mercury removals with activated carbon decrease with increasing temperature, larger particle size, and decreasing mercury concentration in the gas; and chemical pretreatment (e.g., with sulfur or (CaCl{sub 2}) can greatly increase the removal capacity of activated carbon. Preliminary results from the wet scrubbing research include: no removal of elemental mercury is obtained under normal scrubber operating conditions; mercury removal is improved by the addition of packing or production of smaller gas bubbles to increase the gas-liquid contact area; polysulfide solutions do not appear promising for enhancing mercury removal in typical FGC systems; stainless steel packing appears to have beneficial properties for mercury removal and should be investigated further; and other chemical additives may offer greatly enhanced removals.

  11. How does climate change influence Arctic mercury?

    PubMed

    Stern, Gary A; Macdonald, Robie W; Outridge, Peter M; Wilson, Simon; Chételat, John; Cole, Amanda; Hintelmann, Holger; Loseto, Lisa L; Steffen, Alexandra; Wang, Feiyue; Zdanowicz, Christian

    2012-01-01

    Recent studies have shown that climate change is already having significant impacts on many aspects of transport pathways, speciation and cycling of mercury within Arctic ecosystems. For example, the extensive loss of sea-ice in the Arctic Ocean and the concurrent shift from greater proportions of perennial to annual types have been shown to promote changes in primary productivity, shift foodweb structures, alter mercury methylation and demethylation rates, and influence mercury distribution and transport across the ocean-sea-ice-atmosphere interface (bottom-up processes). In addition, changes in animal social behavior associated with changing sea-ice regimes can affect dietary exposure to mercury (top-down processes). In this review, we address these and other possible ramifications of climate variability on mercury cycling, processes and exposure by applying recent literature to the following nine questions; 1) What impact has climate change had on Arctic physical characteristics and processes? 2) How do rising temperatures affect atmospheric mercury chemistry? 3) Will a decrease in sea-ice coverage have an impact on the amount of atmospheric mercury deposited to or emitted from the Arctic Ocean, and if so, how? 4) Does climate affect air-surface mercury flux, and riverine mercury fluxes, in Arctic freshwater and terrestrial systems, and if so, how? 5) How does climate change affect mercury methylation/demethylation in different compartments in the Arctic Ocean and freshwater systems? 6) How will climate change alter the structure and dynamics of freshwater food webs, and thereby affect the bioaccumulation of mercury? 7) How will climate change alter the structure and dynamics of marine food webs, and thereby affect the bioaccumulation of marine mercury? 8) What are the likely mercury emissions from melting glaciers and thawing permafrost under climate change scenarios? and 9) What can be learned from current mass balance inventories of mercury in the Arctic? The

  12. Mercury CEM Calibration

    SciTech Connect

    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

  13. The Mercury-Redstone Program

    NASA Technical Reports Server (NTRS)

    Hammack, Jerome B.; Heberlig, Jack C.

    1961-01-01

    The Mercury-Redstone program is reviewed as to its intended mission and its main results. The progressive results of unmanned, animal, and manned flights of this over-all Project Mercury ballistic training program are presented. A technical description of the major spacecraft systems is presented with some analysis of flight performance. Performance of the spacecraft with and without pilot input is discussed. The influence of the astronaut as an operating link in the over-all system is presented, and relative difficulties of manned versus unmanned flight are briefly commented upon. The program provided information on man as an integral part of a space flight system, demonstrating that man can assume a primary role in space as he does in other realms of flight. The Mercury-Redstone program demonstrated that the Mercury spacecraft was capable of manned space flight, and succeeded in partially qualifying the spacecraft for orbital flight.

  14. Cryogenic control system of the large COMPASS polarized target

    NASA Astrophysics Data System (ADS)

    Gautheron, F.; Ball, J.; Baum, G.; Berglund, P.; Doshita, N.; Goertz, St.; Gustafsson, K.; Horikawa, N.; Kisselev, Y.; Koivuniemi, J.; Kondo, K.; Meyer, W.; Reicherz, G.

    2004-06-01

    The dilution refrigerator used to cool the large COMPASS polarized target is monitored through a PC running LabVIEW TM 6.1 under Windows 2000 TM. About 60 parameters of the target (temperatures, pressures, flow rates) are continuously plotted and checked. They are periodically recorded in an Oracle TM database and in a data file. An alarm for every parameter can be individually activated and optionally connected to a GSM (Global System for Mobile Communication) delivery message system. A web server receives and publishes the online status of the target with online tables and graphics on a dedicated COMPASS polarized target information web site. A Siemens programmable logic controller (PLC) powered by an uninterruptable source keeps the cryogenic system safe and stable during the long beam periods by controlling valves and interlocks. This safety feature protects the dilution refrigerator against potential damages in case of power failure.

  15. Mercury, elemental

    Integrated Risk Information System (IRIS)

    Mercury , elemental ; CASRN 7439 - 97 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinoge

  16. Targeted mutagenesis using CRISPR/Cas system in medaka

    PubMed Central

    Ansai, Satoshi; Kinoshita, Masato

    2014-01-01

    ABSTRACT Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system-based RNA-guided endonuclease (RGEN) has recently emerged as a simple and efficient tool for targeted genome editing. In this study, we showed successful targeted mutagenesis using RGENs in medaka, Oryzias latipes. Somatic and heritable mutations were induced with high efficiency at the targeted genomic sequence on the DJ-1 gene in embryos that had been injected with the single guide RNA (sgRNA) transcribed by a T7 promoter and capped RNA encoding a Cas9 nuclease. The sgRNAs that were designed for the target genomic sequences without the 5′ end of GG required by the T7 promoter induced the targeted mutations. This suggests that the RGEN can target any sequence adjacent to an NGG protospacer adjacent motif (PAM) sequence, which occurs once every 8 bp. The off-target alterations at 2 genomic loci harboring double mismatches in the 18-bp targeting sequences were induced in the RGEN-injected embryos. However, we also found that the off-target effects could be reduced by lower dosages of sgRNA. Taken together, our results suggest that CRISPR/Cas-mediated RGENs may be an efficient and flexible tool for genome editing in medaka. PMID:24728957

  17. Atmospheric mercury emissions from substrates and fumaroles associated with three hydrothermal systems in the western United States

    USGS Publications Warehouse

    Engle, Mark A.; Gustin, Mae S.; Goff, Fraser; Counce, Dale; Janik, Cathy J.; Bergfeld, Deborah; Rytuba, James J.

    2006-01-01

    This paper quantifies atmospheric mercury (Hg) emissions from substrates and fumaroles associated with three hydrothermal systems: Lassen Volcanic Center, California (LVC); Yellowstone Caldera, Wyoming (YC); and Dixie Valley, Nevada (DV). Substrate Hg fluxes were measured using field chamber methods at thermal and nonthermal sites. The highest Hg fluxes (up to 541 ng m−2 h−1) were measured at thermal active areas. Fluxes from altered and unaltered nonthermal sites were <10 ng m−2 h−1 and were comparable to those measured in natural low-Hg background regions for YC and DV, and at LVC they were slightly elevated. Similarly, reactive gaseous mercury concentrations were higher in thermal active areas. Using a Geographic Information System framework for scaling, estimated area-average Hg emissions from substrates were 0.9–3.8 ng m−2 h−1 at LVC, 0.8–2.8 ng m−2 h−1 at YC, and 0.4–0.5 ng m−2 h−1 at DV. At LVC, nonthermal areas were the primary substrate source of atmospheric Hg (>98%). At YC, substrate Hg emissions were dominated (50 to 90%) by acidically altered thermal areas. Substrate emissions at DV were low and primarily from nonthermal areas (66% to 75%). Fumarole emissions at LVC (91–146 kg yr−1) and YC (0.18–1.6 kg yr−1 for Mud Volcano) were estimated by applying Hg:H2O and Hg:CO2 ratios in hydrothermal gas samples to H2O and CO2 emissions. Applying total area-average emissions from substrates and thermal features at LVC, YC, and DV to similar systems across the conterminous United States, yearly atmospheric Hg emissions from active hydrothermal systems are projected to be 1.3–2.1 Mg.

  18. Factors affecting water strider (Hemiptera: Gerridae) mercury concentrations in lotic systems

    SciTech Connect

    Jardine, T.D.; Kidd, K.A.; Cunjak, R.A.; Arp, P.A.

    2009-07-15

    Water striders (Hemiptera: Gerridae) have been considered as a potential sentinel for mercury (Hg) contamination of freshwater ecosystems, yet little is known about factors that control Hg concentrations in this invertebrate. Striders were collected from 80 streams and rivers in New Brunswick, Canada, in August and September of 2004 through 2007 to assess the influence of factors such as diet, water chemistry, and proximity to point sources on Hg concentrations in this organism. Higher than average Hg concentrations were observed in the southwest and Grand Lake regions of the province, the latter being the location of a coal-fired power plant that is a source of Hg (similar to 100 kg annually), with elevated Hg concentrations in the lichen Old Man's Beard (Usnea spp.) in its immediate vicinity. Across all streams, pH and total organic carbon of water were relatively weak predictors of strider Hg concentrations. Female striders that were larger in body size than males had significantly lower Hg concentrations within sites, suggestive of growth dilution. There was no relationship between percent aquatic carbon in the diet and Hg concentrations in striders. For those striders feeding solely on terrestrial carbon, Hg concentrations were higher in animals occupying a higher trophic level. Mercury concentrations were highly variable in striders collected monthly over two growing seasons, suggesting short-term changes in Hg availability. These measurements highlight the importance of considering both deposition and postdepositional processes in assessing Hg bioaccumulation in this species.

  19. Environmental Mercury and Its Toxic Effects

    PubMed Central

    Rice, Kevin M.; Walker, Ernest M.; Wu, Miaozong; Gillette, Chris

    2014-01-01

    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. PMID:24744824

  20. Environmental mercury and its toxic effects.

    PubMed

    Rice, Kevin M; Walker, Ernest M; Wu, Miaozong; Gillette, Chris; Blough, Eric R

    2014-03-01

    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. PMID:24744824

  1. Recent geologic activity on Mercury

    NASA Astrophysics Data System (ADS)

    Xiao, Z.; Strom, R. G.; Blewett, D. T.; Solomon, S. C.; Head, J. W.; Watters, T. R.; Chabot, N. L.; Banks, M. E.; Chapman, C. R.

    2011-12-01

    Since the MESSENGER spacecraft was inserted into orbit about Mercury in March 2011, global and targeted high-resolution image data sets have been acquired. These images support the conclusion that internal geological activity on Mercury did not end early in planetary history, as had generally been previously thought, but continued to geologically recent times. Three lines of evidence point to recent geological activity on Mercury. (1) There are smooth plains with surface areas up to 1.5×105 km2 that postdate young (morphological class 1) craters, indicating probable Kuiperian-aged volcanism. No volcanic vents, fissures, or flow fronts have been identified on these plains, suggesting that they are products of low-viscosity lavas, consistent with komatiite-like compositions of large areas on Mercury indicated by MESSENGER X-Ray Spectrometer observations. (2) Young lobate scarps transect class 1 craters as large as 30 km in diameter, indicating comparably recent crustal contraction. (3) A number of fresh-appearing, high-reflectance, irregularly shaped and rimless shallow depressions interpreted as pyroclastic vents have few superposed craters, suggesting that they have been recently active. Growing evidence from geological and geochemical observations indicates that Mercury's interior contains a higher abundance of volatile materials than was previously appreciated. Together these findings support the inference that Mercury experienced relatively recent volcanism and tectonic deformation, and the possibility that the planet is geologically active today cannot be discounted.

  2. Alkaline sorbent injection for mercury control

    DOEpatents

    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.

  3. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2003-01-01

    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.

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

    SciTech Connect

    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.

  5. A dual-inlet, single detector relaxed eddy accumulation system for long-term measurement of mercury flux

    NASA Astrophysics Data System (ADS)

    Osterwalder, S.; Fritsche, J.; Alewell, C.; Schmutz, M.; Nilsson, M. B.; Jocher, G.; Sommar, J.; Rinne, J.; Bishop, K.

    2016-02-01

    The fate of anthropogenic emissions of mercury (Hg) to the atmosphere is influenced by the exchange of elemental Hg with the earth surface. This exchange holds the key to a better understanding of Hg cycling from local to global scales, which has been difficult to quantify. To advance research about land-atmosphere Hg interactions, we developed a dual-inlet, single detector relaxed eddy accumulation (REA) system. REA is an established technique for measuring turbulent fluxes of trace gases and aerosol particles in the atmospheric surface layer. Accurate determination of gaseous elemental mercury (GEM) fluxes has proven difficult due to technical challenges presented by extremely small concentration differences (typically < 0.5 ng m-3) between updrafts and downdrafts. We present an advanced REA design that uses two inlets and two pairs of gold cartridges for continuous monitoring of GEM fluxes. This setup reduces the major uncertainty created by the sequential sampling in many previous designs. Additionally, the instrument is equipped with a GEM reference gas generator that monitors drift and recovery rates. These innovations facilitate continuous, autonomous measurement of GEM flux. To demonstrate the system performance, we present results from field campaigns in two contrasting environments: an urban setting with a heterogeneous fetch and a boreal peatland during snowmelt. The observed average emission rates were 15 and 3 ng m-2 h-1, respectively. We believe that this dual-inlet, single detector approach is a significant improvement of the REA system for ultra-trace gases and can help to advance our understanding of long-term land-atmosphere GEM exchange.

  6. Distributed visual-target-surveillance system in wireless sensor networks.

    PubMed

    Wang, Xue; Wang, Sheng; Bi, Daowei

    2009-10-01

    A wireless sensor network (WSN) is a powerful unattended distributed measurement system, which is widely used in target surveillance because of its outstanding performance in distributed sensing and signal processing. This paper introduces a multiview visual-target-surveillance system in WSN, which can autonomously implement target classification and tracking with collaborative online learning and localization. The proposed system is a hybrid system of single-node and multinode fusion. It is constructed on a peer-to-peer (P2P)-based computing paradigm and consists of some simple but feasible methods for target detection and feature extraction. Importantly, a support-vector-machine-based semisupervised learning method is used to achieve online classifier learning with only unlabeled samples. To reduce the energy consumption and increase the accuracy, a novel progressive data-fusion paradigm is proposed for online learning and localization, where a feasible routing method is adopted to implement information transmission with the tradeoff between performance and cost. Experiment results verify that the proposed surveillance system is an effective, energy-efficient, and robust system for real-world application. Furthermore, the P2P-based progressive data-fusion paradigm can improve the energy efficiency and robustness of target surveillance. PMID:19336319

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

    PubMed

    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. PMID:27155100

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

    SciTech Connect

    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. Plane Mercury librations

    NASA Astrophysics Data System (ADS)

    Barkin, Yu. V.; Ferrandiz, J. M.

    2009-04-01

    theory of Mercury librations in longitude by using three characteristics of Mercury rotation determined in the paper [3]. Two from these parameters are values of angle of librations in longitude and angular velocity in moment of passage of perihelion of Mercury orbit on 17 April 2002: (^g)0 = 0007 ± 0001, (^?•? )0 = (2.10± 0.06)•? ars/d. Third parameter determined in [3] is a dynamical coefficient: K = (B -A)•(4Cm ) = (5.08± 0.30) × 10-5. B > A are principal moment of inertia, corresponding to equatorial axes of inertia; Cm is a polar moment of inertia of the mantle of Mercury. 1 Analytical theory of plane Mercury librations. This theory describes forced and free librations of Mercury in longitude in the frame of plane problem about resonant librations of Mercury considered or as non-spherical rigid body, or as system of rigid non-spherical mantle and liquid ellipsoidal core. Saving the main terms for the perturbations of angle of librations ^g and angular velocity ^? in both mentioned cases we will have formulae [6]: ^g = K(E sin M + E sin2M + E sin 3M + E sin4M + E sin5M ) 1 2 3 4 5+K0 sin(E šKM- - φ) (A)

  10. Elemental mercury removal using a wet scrubber

    SciTech Connect

    Martin, K.; Gonzalez, E.; Zhou, C.Q.; Livengood, C.D.; Mendelsohn, M.H.

    1999-11-01

    Mercury (Hg) is a toxic metal that is emitted into the environment by both natural and human activities. Acute and chronic exposure to mercury and methyl mercury in humans results in central nervous system damage, kidney damage, and even death. Although some Hg emission sources have been regulated, coal-fired utilities have not been. In anticipation of federal regulations on mercury emissions from coal fired power plants, Argonne National Laboratory (ANL) has designed a flue gas simulation system to study the removal of elemental mercury. The simulated flue gas enters the system and combines with the inlet mercury vapor (from a calibrated permeation tube), carried by nitrogen gas. This combined gas continues past the flow meter and the pressure gage to the reactor inlet. Inside the reactor chamber, the flue gas is sprayed with NOXSORB{reg_sign} a chloric acid solution, which reacts with elemental mercury. The amount of reaction (oxidation) of elemental mercury is important since mercury in an oxidized form is highly soluble. In this form the Hg can be picked up downstream by a wet scrubber. Experiments on mercury removal from flue gases have been conducted at ANL, with the participation of a senior design team from Purdue University Calumet. A literature survey on the current and proposed mercury control legislation, along with the existing control technologies has been performed as part of the senior design project. The experimental results obtained at Argonne will be related to existing wet scrubber technology to determine the economic feasibility of mercury removal. A cost per pound of mercury analysis will be utilized.

  11. Morphometry of impact craters on Mercury from MESSENGER altimetry and imaging

    NASA Astrophysics Data System (ADS)

    Susorney, Hannah C. M.; Barnouin, Olivier S.; Ernst, Carolyn M.; Johnson, Catherine L.

    2016-06-01

    Data acquired by the Mercury Laser Altimeter and the Mercury Dual Imaging System on the MESSENGER spacecraft in orbit about Mercury provide a means to measure the geometry of many of the impact craters in Mercury's northern hemisphere in detail for the first time. The combination of topographic and imaging data permit a systematic evaluation of impact crater morphometry on Mercury, a new calculation of the diameter Dt at which craters transition with increasing diameter from simple to complex forms, and an exploration of the role of target properties and impact velocity on final crater size and shape. Measurements of impact crater depth on Mercury confirm results from previous studies, with the exception that the depths of large complex craters are typically shallower at a given diameter than reported from Mariner 10 data. Secondary craters on Mercury are generally shallower than primary craters of the same diameter. No significant differences are observed between the depths of craters within heavily cratered terrain and those of craters within smooth plains. The morphological attributes of craters that reflect the transition from simple to complex craters do not appear at the same diameter; instead flat floors first appear with increasing diameter in craters at the smallest diameters, followed with increasing diameter by reduced crater depth and rim height, and then collapse and terracing of crater walls. Differences reported by others in Dt between Mercury and Mars (despite the similar surface gravitational acceleration on the two bodies) are confirmed in this study. The variations in Dt between Mercury and Mars cannot be adequately attributed to differences in either surface properties or mean projectile velocity.

  12. MERCURY IN TREE RINGS

    EPA Science Inventory

    Contamination caused by release of mercury into the environment is a growing concern. This release occurs due to a variety of anthropogenic activities and natural sources. After release, mercury undergoes complicated chemical transformations. The inorganic forms of mercury releas...

  13. An ultra-stable referenced interrogation system in the deep ultraviolet for a mercury optical lattice clock

    NASA Astrophysics Data System (ADS)

    Dawkins, S. T.; Chicireanu, R.; Petersen, M.; Millo, J.; Magalhães, D. V.; Mandache, C.; Le Coq, Y.; Bize, S.

    2010-04-01

    We have developed an ultra-stable source in the deep ultraviolet, suitable to fulfil the interrogation requirements of a future fully-operational lattice clock based on neutral mercury. At the core of the system is a Fabry-Pérot cavity which is highly impervious to temperature and vibrational perturbations. The mirror substrate is made of fused silica in order to exploit the comparatively low thermal noise limits associated with this material. By stabilizing the frequency of a 1062.6 nm Yb-doped fiber laser to the cavity, and including an additional link to LNE-SYRTE’s fountain primary frequency standards via an optical frequency comb, we produce a signal which is both stable at the 10-15 level in fractional terms and referenced to primary frequency standards. The signal is subsequently amplified and frequency-doubled twice to produce several milliwatts of interrogation signal at 265.6 nm in the deep ultraviolet.

  14. A Secure and Privacy-Preserving Targeted Ad-System

    NASA Astrophysics Data System (ADS)

    Androulaki, Elli; Bellovin, Steven M.

    Thanks to its low product-promotion cost and its efficiency, targeted online advertising has become very popular. Unfortunately, being profile-based, online advertising methods violate consumers' privacy, which has engendered resistance to the ads. However, protecting privacy through anonymity seems to encourage click-fraud. In this paper, we define consumer's privacy and present a privacy-preserving, targeted ad system (PPOAd) which is resistant towards click fraud. Our scheme is structured to provide financial incentives to all entities involved.

  15. Small Mercury Relativity Orbiter

    NASA Technical Reports Server (NTRS)

    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.

  16. A novel multiple target tracking system for UAV platforms

    NASA Astrophysics Data System (ADS)

    Yi, Steven; Zhang, Libin

    2006-05-01

    In this paper, we introduce Genex's innovative multiple target tracking system (i.e. SmartMTI algorithm and our miniature DSP/FPGA data processing hardware). SmartMTI is designed for intelligent surveillance on moving platforms such as UAVs (unmmaned Aerial Vehicle), UGV (unmanned ground vehicle), and manned moving platforms. It uses our state-machine MTI framework to seamlessly integrate our state-of-the-art motion detection and target tracking methods to create multiple target following and inter-object 'awareness', thus allowing the system to robustly handle difficult situations such as targets under merging, occlusion, and disappearing conditions. Preliminary tests show that, once implemented on our miniaturized DSP/FPGA hardware, our system can detect and track multiple targets in real time with extremely low miss-detection rate. The SmartMTI design effort leverages Genex's expertise and experience in real-time surveillance system design for the Army's AMCOM's SCORPION or "Glide Bomb" program, NUWC's CERBERUS program, BMDO's missile seeker program, Air Force's UAV auto-navigation and surveillance program, and DARPA's Future Combat System (FCS) program.

  17. The Tectonics of Mercury: The View from Orbit

    NASA Astrophysics Data System (ADS)

    Watters, T. R.; Byrne, P. K.; Klimczak, C.; Enns, A. C.; Banks, M. E.; Walsh, L. S.; Ernst, C. M.; Robinson, M. S.; Gillis-Davis, J. J.; Solomon, S. C.; Strom, R. G.; Gwinner, K.

    2011-12-01

    Flybys of Mercury by the Mariner 10 and MESSENGER spacecraft revealed a broad distribution of contractional tectonic landforms, including lobate scarps, high-relief ridges, and wrinkle ridges. Among these, lobate scarps were seen as the dominant features and have been interpreted as having formed as a result of global contraction in response to interior cooling. Extensional troughs and graben, where identified, were generally confined to intermediate- to large-scale impact basins. However, the true global spatial distribution of tectonic landforms remained poorly defined because the flyby observations were limited in coverage and spatial resolution, and many flyby images were obtained under lighting geometries far from ideal for the detection and identification of morphologic features. With the successful insertion of MESSENGER into orbit in March 2011, we are exploiting the opportunity to characterize the tectonics of Mercury in unprecedented detail using images at high resolution and optimum lighting, together with topographic data obtained from Mercury Laser Altimeter (MLA) profiles and stereo imaging. We are digitizing all of Mercury's major tectonic landforms in a standard geographic information system format from controlled global monochrome mosaics (mean resolution 250 m/px), complemented by high-resolution targeted images (up to ~10 m/px), obtained by the Mercury Dual Imaging System (MDIS) cameras. On the basis of an explicit set of diagnostic criteria, we are mapping wrinkle ridges, high-relief ridges, lobate scarps, and extensional troughs and graben in separate shapefiles and cataloguing the segment endpoint positions, length, and orientation for each landform. The versatility of digital mapping facilitates the merging of this tectonic information with other MESSENGER-derived map products, e.g., volcanic units, surface color, geochemical variations, topography, and gravity. Results of this mapping work to date include the identification of extensional

  18. Exploring the Solar System: Ice Hunters, Mercury Zoo, and Planet Investigators

    NASA Astrophysics Data System (ADS)

    Gay, P. L.; Lehan, C.; Conti, A.; Deustua, S.; Mutchler, M.; Wong, M.; Higgins, J.; Buie, M. W.; Spencer, J.; Robbins, S.; Chapman, C.; Hirshon, R.; Lerner, T.

    2011-10-01

    A new suite of citizen science software, "Community Science Builder" (CSB) has been created to facilitate exploration and annotation of space images. First launched as the backbone of "Ice Hunters," this software is designed to facilitate planetary science that requires images to be annotated by users. Initial features include: marking objects with a set of predefined markers and an administration dashboard for expert review of incoming annotations. Beginning with the release of "Planet Investigators" and "Mercury Zoo" in late 2011, CSB will also allow moving objects to be matched between frames, linear features to be traced, and interesting features to be annotated with flags and comments. In this paper we discuss upcoming projects, and the software's features and flexibility for generating science.

  19. Diagnostic system design for the Ion Auxiliary Propulsion System (IAPS). Flight tests of two 8 cm mercury ion

    NASA Technical Reports Server (NTRS)

    Hurst, E. B.; Thomas, G. Z.

    1981-01-01

    The mechanical, thermal, electrical design and the ground test results of four types of detectors are explained. The DSS is designed to measure the thruster efflux material deposition and S/C potential relative to the local plasma in the vicinity of two 8 cm mercury ion thrusters. The DSS consists of two quartz crystal microbalance (QCM) detectors, one potential probe, nine solar cell arrays, seven ion collectors and two electronic packages.

  20. Factors affecting water strider (Hemiptera: Gerridae) mercury concentrations in lotic systems.

    PubMed

    Jardine, Timothy D; Kidd, Karen A; Cunjak, Richard A; Arp, Paul A

    2009-07-01

    Water striders (Hemiptera: Gerridae) have been considered as a potential sentinel for mercury (Hg) contamination of freshwater ecosystems, yet little is known about factors that control Hg concentrations in this invertebrate. Striders were collected from 80 streams and rivers in New Brunswick, Canada, in August and September of 2004 through 2007 to assess the influence of factors such as diet, water chemistry, and proximity to point sources on Hg concentrations in this organism. Higher than average Hg concentrations were observed in the southwest and Grand Lake regions of the province, the latter being the location of a coal-fired power plant that is a source of Hg (approximately 100 kg annually), with elevated Hg concentrations in the lichen Old Man's Beard (Usnea spp.) in its immediate vicinity. Across all streams, pH and total organic carbon of water were relatively weak predictors of strider Hg concentrations. Female striders that were larger in body size than males had significantly lower Hg concentrations within sites, suggestive of growth dilution. There was no relationship between percent aquatic carbon in the diet and Hg concentrations in striders. For those striders feeding solely on terrestrial carbon, Hg concentrations were higher in animals occupying a higher trophic level. Mercury concentrations were highly variable in striders collected monthly over two growing seasons, suggesting short-term changes in Hg availability. These measurements highlight the importance of considering both deposition and postdepositional processes in assessing Hg bioaccumulation in this species. They also suggest that striders may be more appropriate as a terrestrial rather than an aquatic Hg sentinel, underscoring the importance of understanding the origin of food for organisms used in contaminant studies. PMID:19215185

  1. INVENTORY OF COMMON LOON, GAVIA IMMER, AND MERCURY DATA COLLECTED IN NEW ENGLAND: A GEOGRAPHIC INFORMATION SYSTEM ANALYSIS

    EPA Science Inventory

    The common loon, Gavia immer. suffers adverse health effects following exposure to mercury. This contaminant enters the environment from industrial air emissions, travels through the atmosphere and is deposited into water and sediment. From here, mercury enters fish which are the...

  2. Systems approaches to design of targeted therapeutic delivery.

    PubMed

    Myerson, Jacob W; Brenner, Jacob S; Greineder, Colin F; Muzykantov, Vladimir R

    2015-01-01

    Targeted drug delivery aims to improve therapeutic effects and enable mechanisms that are not feasible for untargeted agents (e.g., due to impermeable biological barriers). To achieve targeting, a drug or its carrier should possess properties providing specific accumulation from circulation at the desired site. There are several examples of systems-inspired approaches that have been applied to achieve this goal. First, proteomics analysis of plasma membrane fraction of the vascular endothelium has identified a series of target molecules and their ligands (e.g., antibodies) that deliver conjugated cargoes to well-defined vascular cells and subcellular compartments. Second, selection of ligands binding to cells of interest using phage display libraries in vitro and in vivo has provided peptides and polypeptides that bind to normal and pathologically altered cells. Finally, large-scale high-throughput combinatorial synthesis and selection of lipid- and polymer-based nanocarriers varying their chemical components has yielded a series of carriers accumulating in diverse organs and delivering RNA interference agents to diverse cells. Together, these approaches offer a basis for systems-based design and selection of targets, targeting molecules, and targeting vehicles. Current studies focus on expanding the arsenal of these and alternative targeting strategies, devising drug delivery systems capitalizing on these strategies and evaluation of their benefit/risk ratio in adequate animal models of human diseases. These efforts, combined with better understanding of mechanisms and unintended consequences of these targeted interventions, need to be ultimately translated into industrial development and the clinical domain. PMID:25946066

  3. Systems approaches to design of targeted therapeutic delivery

    PubMed Central

    Myerson, Jacob W.; Brenner, Jacob S.; Greineder, Colin F.; Muzykantov, Vladimir R.

    2016-01-01

    Targeted drug delivery aims to improve therapeutic effects and enable mechanisms that are not feasible for untargeted agents (e.g., due to impermeable biological barriers). To achieve targeting, a drug or its carrier should possess properties providing specific accumulation from circulation at the desired site. There are several examples of systems-inspired approaches that have been applied to achieve this goal. First, proteomics analysis of plasma membrane fraction of the vascular endothelium has identified a series of target molecules and their ligands (e.g., antibodies) that deliver conjugated cargoes to well-defined vascular cells and subcellular compartments. Second, selection of ligands binding to cells of interest using phage display libraries in vitro and in vivo has provided peptides and polypeptides that bind to normal and pathologically altered cells. Finally, large-scale high-throughput combinatorial synthesis and selection of lipid- and polymer-based nanocarriers varying their chemical components has yielded a series of carriers accumulating in diverse organs and delivering RNA interference agents to diverse cells. Together, these approaches offer a basis for systems-based design and selection of targets, targeting molecules, and targeting vehicles. Current studies focus on expanding the arsenal of these and alternative targeting strategies, devising drug delivery systems capitalizing on these strategies and evaluation of their benefit/risk ratio in adequate animal models of human diseases. These efforts, combined with better understanding of mechanisms and unintended consequences of these targeted interventions, need to be ultimately translated into industrial development and the clinical domain. PMID:25946066

  4. Target isolation system, high power laser and laser peening method and system using same

    DOEpatents

    Dane, C. Brent; Hackel, Lloyd A.; Harris, Fritz

    2007-11-06

    A system for applying a laser beam to work pieces, includes a laser system producing a high power output beam. Target delivery optics are arranged to deliver the output beam to a target work piece. A relay telescope having a telescope focal point is placed in the beam path between the laser system and the target delivery optics. The relay telescope relays an image between an image location near the output of the laser system and an image location near the target delivery optics. A baffle is placed at the telescope focal point between the target delivery optics and the laser system to block reflections from the target in the target delivery optics from returning to the laser system and causing damage.

  5. Hybrid-integrated prism array optoelectronic targeting system

    NASA Astrophysics Data System (ADS)

    Chang, C. C.; Chang, H. C.; Tang, L. C.; Young, W. K.; Wang, J. C.; Huang, K. L.

    2005-11-01

    This investigation proposes a cost-effective, compact, and robust optoelectronic targeting system for measuring ballistic impact velocity and the distribution of projectile motion. The major elements of this system are four photo-gates hybridized by compound one-dimensional prism array and analog/digital electronic components. The number of light sources and photodetectors used in a photo-gate was reduced to one pair of light source and photodetector. The average velocity and location of the projectile are determined according to the measured time intervals ( ˜10 -8 s) passing each pair. The system can accurately measure the velocity of a bullet as it leaves a gun barrel, as well as the velocity at specific points along the trajectory outside the firearm. Additionally, the system uses a widespread low-powered laser pointer as a light source. Compared with other optoelectronic targeting systems that use high-powered lasers, the proposed system is both economical and safe.

  6. A high-power target experiment at the CERN PS

    SciTech Connect

    Kirk, H.G.; Park, H.J.; Tsang, T.; Fabich, A.; Efthymiopoulos, I.; Haug, F.; Lettry, J.; Palm, M.; Mokhov, N.V.; Striganov, S.; Carroll, A.; /Oak Ridge /Princeton U. /Rutherford

    2007-06-01

    We test a target concept devised for the purpose of producing copious secondary pions and capturing the muon decay products. This experiment is designed to test the target system for a neutrino factory or muon collider and consists of a free flowing mercury stream embedded in a high-field solenoid. Key components are described.

  7. Mercury control in 2009

    SciTech Connect

    Sjostrom, S.; Durham, M.; Bustard, J.; Martin, C.

    2009-07-15

    Although activated carbon injection (ACI) has been proven to be effective for many configurations and is a preferred option at many plants sufficient quantities of powdered activated coking (PAC) must be available to meet future needs. The authors estimate that upcoming federal and state regulations will result in tripling the annual US demand for activated carbon to nearly 1.5 billion lb from approximately 450 million lb. Rapid expansion of US production capacity is required. Many PAC manufacturers are discussing expansion of their existing production capabilities. One company, ADA Carbon Solutions, is in the process of constructing the largest activated carbon facility in North America to meet the future demand for PAC as a sorbent for mercury control. Emission control technology development and commercialization is driven by regulation and legislation. Although ACI will not achieve > 90% mercury control at every plant, the expected required MACT legislation level, it offers promise as a low-cost primary mercury control technology option for many configurations and an important trim technology for others. ACI has emerged as the clear mercury-specific control option of choice, representing over 98% of the commercial mercury control system orders to date. As state regulations are implemented and the potential for a federal rule becomes more imminent, suppliers are continuing to develop technologies to improve the cost effectiveness and limit the balance of plant impacts associated with ACI and are developing additional PAC production capabilities to ensure that the industry's needs are met. The commercialisation of ACI is a clear example of industry, through the dedication of many individuals and companies with support from the DOE and EPRI, meeting the challenge of developing cost-effectively reducing emissions from coal-fired power plants. 7 refs., 1 fig.

  8. The Atmospheric Mercury Network: measurement and initial examination of an ongoing atmospheric mercury record across North America

    NASA Astrophysics Data System (ADS)

    Gay, D. A.; Schmeltz, D.; Prestbo, E.; Olson, M.; Sharac, T.; Tordon, R.

    2013-04-01

    The National Atmospheric Deposition Program (NADP) developed and operates a collaborative network of atmospheric mercury monitoring sites based in North America - the Atmospheric Mercury Network (AMNet). The justification for the network was growing interest and demand from many scientists and policy makers for a robust database of measurements to improve model development, assess policies and programs, and improve estimates of mercury dry deposition. Many different agencies and groups support the network, including federal, state, tribal, and international governments, academic institutions, and private companies. AMNet has added two high elevation sites outside of continental North America in Hawaii and Taiwan because of new partnerships forged within NADP. Network sites measure concentrations of atmospheric mercury fractions using automated, continuous mercury speciation systems. The procedures that NADP developed for field operations, data management, and quality assurance ensure that the network makes scientifically valid and consistent measurements. AMNet reports concentrations of hourly gaseous elemental mercury (GEM), two-hour gaseous oxidized mercury (GOM), and two-hour particulate-bound mercury less than 2.5 microns in size (PBM2.5). As of January 2012, over 450 000 valid observations are available from 30 stations. The AMNet also collects ancillary meteorological data and information on land-use and vegetation, when available. We present atmospheric mercury data comparisons by time (3 yr) at 22 unique site locations. Highlighted are contrasting values for site locations across the network: urban versus rural, coastal versus high-elevation and the range of maximum observations. The data presented should catalyze the formation of many scientific questions that may be answered through further in-depth analysis and modeling studies of the AMNet database. All data and methods are publically available through an online database on the NADP website (

  9. The Atmospheric Mercury Network: measurement and initial examination of an ongoing atmospheric mercury record across North America

    NASA Astrophysics Data System (ADS)

    Gay, D. A.; Schmeltz, D.; Prestbo, E.; Olson, M.; Sharac, T.; Tordon, R.

    2013-11-01

    The National Atmospheric Deposition Program (NADP) developed and operates a collaborative network of atmospheric-mercury-monitoring sites based in North America - the Atmospheric Mercury Network (AMNet). The justification for the network was growing interest and demand from many scientists and policy makers for a robust database of measurements to improve model development, assess policies and programs, and improve estimates of mercury dry deposition. Many different agencies and groups support the network, including federal, state, tribal, and international governments, academic institutions, and private companies. AMNet has added two high-elevation sites outside of continental North America in Hawaii and Taiwan because of new partnerships forged within NADP. Network sites measure concentrations of atmospheric mercury fractions using automated, continuous mercury speciation systems. The procedures that NADP developed for field operations, data management, and quality assurance ensure that the network makes scientifically valid and consistent measurements. AMNet reports concentrations of hourly gaseous elemental mercury (GEM), two-hour gaseous oxidized mercury (GOM), and two-hour particulate-bound mercury less than 2.5 microns in size (PBM2.5). As of January 2012, over 450 000 valid observations are available from 30 stations. AMNet also collects ancillary meteorological data and information on land use and vegetation, when available. We present atmospheric mercury data comparisons by time (3 yr) at 21 individual sites and instruments. Highlighted are contrasting values for site locations across the network: urban versus rural, coastal versus high elevation and the range of maximum observations. The data presented should catalyze the formation of many scientific questions that may be answered through further in-depth analysis and modeling studies of the AMNet database. All data and methods are publically available through an online database on the NADP website (

  10. Targeting protein kinases in central nervous system disorders

    PubMed Central

    Chico, Laura K.; Van Eldik, Linda J.; Watterson, D. Martin

    2010-01-01

    Protein kinases are a growing drug target class in disorders in peripheral tissues, but the development of kinase-targeted therapies for central nervous system (CNS) diseases remains a challenge, largely owing to issues associated specifically with CNS drug discovery. However, several candidate therapeutics that target CNS protein kinases are now in various stages of preclinical and clinical development. We review candidate compounds and discuss selected CNS protein kinases that are emerging as important therapeutic targets. In addition, we analyse trends in small-molecule properties that correlate with key challenges in CNS drug discovery, such as blood–brain barrier penetrance and cytochrome P450-mediated metabolism, and discuss the potential of future approaches that will integrate molecular-fragment expansion with pharmacoinformatics to address these challenges. PMID:19876042

  11. Visual tracking system for water surface moving targets

    NASA Astrophysics Data System (ADS)

    Zheng, Lin; Beetz, Michael; Gedikli, Suat

    2007-11-01

    Water surface moving targets tracking is a challenging problem in the field of computer vision. Because moving targets are in a cluttered environment and are occluded randomly by splashed water, it is difficult to accurately extract and track them. In this paper, by analyzing water surface's color and motion statistical characteristics, a two-step segmentation algorithm is proposed to extract these targets. Then a multi-view tracking systme is established to estimate the 3D trajectory of moving targets' center. We employ this system to canoe competition, and to compare our result with the standard 3D trajectories, which can be calculated by using the markers on the canoes. THe experiments show that the root median square error between our trajectories and the standard ones is very low.

  12. Polarization effects on hard target calibration of lidar systems.

    PubMed

    Kavaya, M J

    1987-03-01

    The theory of hard target calibration of lidar backscatter data, including laboratory measurements of the pertinent target reflectance parameters, is extended to include the effects of polarization of the transmitted and received laser radiation. The bidirectional reflectance-distribution function model of reflectance is expanded to a 4 x 4 matrix allowing Mueller matrix and Stokes vector calculus to be employed. Target reflectance parameters for calibration of lidar backscatter data are derived for various lidar system polarization configurations from integrating sphere and monostatic reflectometer measurements. It is found that correct modeling of polarization effects is mandatory for accurate calibration of hard target reflectance parameters and, therefore, for accurate calibration of lidar backscatter data. PMID:20454226

  13. MERCURY STABILITY IN THE ENVIRONMENT

    SciTech Connect

    John H. Pavlish

    1999-07-01

    The 1990 Clean Air Act Amendments (CAAAs) require the U.S. Environmental Protection Agency (EPA) to determine whether the presence of mercury and 188 other trace substances, referred to as air toxics or hazardous air pollutants (HAPs), in the stack emissions from fossil fuel-fired electric utility power plants poses an unacceptable public health risk (1). The EPA's conclusions and recommendations were presented in two reports: Mercury Study Report to Congress and Study of Hazardous Air Pollutant Emissions from Electric Utility Steam Generating Units-Final Report to Congress. The first congressional report addressed both human health and the environmental effects of anthropogenic mercury emissions, while the second report addressed the risk to public health posed by emissions of HAPs from steam electricity-generating units. The National Institute of Environmental Health Sciences is also required by the CAAAs to investigate mercury and determine a safe threshold level of exposure. Recently the National Academy of Sciences has also been commissioned by Congress to complete a report, based the available scientific evidence, regarding safe threshold levels of mercury exposure. Although the EPA reports did not state that mercury controls on coal-fired electric power stations should be required given the current state of the art, they did indicate that EPA views mercury as a potential threat to human health. It is likely that major sources of mercury emissions, including fossil-fired combustion systems, will be controlled at some point. In fact, municipal waste combustion units are already regulated. In anticipation of additional control measures, much research has been done (and continues) regarding the development of control technologies for mercury emitted from stationary sources to the atmosphere. Most approaches taken to date involve sorbent injection technologies or improve upon removal of mercury using existing technologies such as flue gas desulfurization

  14. The Targeted-liposome Delivery System of Antitumor Drugs.

    PubMed

    Wu, Wei-dang; Yi, Xiu-lin; Jiang, Li-xin; Li, Ya-zhuo; Gao, Jing; Zeng, Yong; Yi, Rong-da; Dai, Li-peng; Li, Wei; Ci, Xiao-yan; Si, Duan-yun; Liu, Chang-xiao

    2015-01-01

    The liposome delivery system has been intensively explored as novel drug delivery system (DDS) for antitumor drugs, due to its safety, selective cytotoxicity, long circulation and slow elimination in blood, which is favorable for cancer therapy. The liposome-based chemotherapeutics are used to treat a variety of cancers to enhance the therapeutic index of antitumor drugs. Here, the author reviewed the important targets for cancer therapy and the pharmacokinetic behavior of liposomal drugs in vivo, as well as the application of the targeting liposomal system in cancer therapy. Considering further application for clinical use, the great challenges of the liposome-based delivery system were also proposed as follows: 1) prepare stealth liposome with steric stabilization and further enhance the therapeutic effects and safety; 2) explore more safe clinical targets and complementary or different types of targeting liposome; 3) thirdly, more investment is needed on the research of pharmacokinetics of the elements such as the ligands (antibody), PEG and lipids of liposome delivery system as well as safety evaluation. Considering the complex process of the liposomal encapsulation drugs in vivo, the author inferred that there are maybe different forms of the encapsulation drug to be internalized by the tumor tissues at the same time and space, although there are little reports on it. PMID:26652257

  15. Multi-agent system for target-adaptive radar tracking

    NASA Astrophysics Data System (ADS)

    O'Connor, Alan C.

    2012-06-01

    Sensor systems such as distributed sensor networks and radar systems are potentially agile - they have parameters that can be adjusted in real-time to improve the quality of data obtained for state-estimation and decision-making. The integration of such sensors with cyber systems involving many users or agents permits greater flexibility in choosing measurement actions. This paper considers the problem of selecting radar waveforms to minimize uncertainty about the state of a tracked target. Past work gave a tractable method for optimizing the choice of measurements when an accurate dynamical model is available. However, prior knowledge about a system is often not precise, for example, if the target under observation is an adversary. A multiple agent system is proposed to solve the problem in the case of uncertain target dynamics. Each agent has a different target model and the agents compete to explain past data and select the parameters of future measurements. Collaboration or competition between these agents determines which obtains access to the limited physical sensing resources. This interaction produces a self-aware sensor that adapts to changing information requirements.

  16. Testing of Continuous Sampling Air-ICP and Mercury Systems as Continuous Emission Monitors at the Diagnostic Instrumentation and Analysis Laboratory

    SciTech Connect

    D.P. Baldwin; S.J. Bajic; D.E. Eckels; D.S. Zamzow; G.P. Miller; S. Tao; C.A. Waggoner

    2001-03-15

    This report has been prepared to document the performance of the continuous sampling reduced-pressure air-ICP-AES (inductively coupled plasma--atomic emission spectroscopy) and mercury-monitor systems developed by Ames Laboratory for use as continuous emission monitors (CEM). This work was funded by the U. S. Department of Energy, Office of Environmental Management, Office of Science and Technology, through the Mixed Waste Focus Area. The purpose of the project is to develop instrumentation and methods for spectroscopic field monitoring applications. During FY00 this included continued work on the development of the continuous sample introduction system and the multi-frequency AOTF-echelle spectrometer, used in conjunction with the reduced-pressure air-ICP-AES system as a multi-metal CEM. The assembly, development, and testing of an echelle spectrometer system for the detection of mercury (Hg) by atomic absorption was also completed during FY00. The continuous sampling system and the multi-metal air-ICP and mercury-monitor CEM systems were tested at Mississippi State University at the Diagnostic Instrumentation and Analysis Laboratory (DIAL) at the end of FY00. This report describes the characteristics and performance of these systems, and the results of the field tests performed at DIAL.

  17. Transpressional Structures on Mercury

    NASA Astrophysics Data System (ADS)

    Massironi, M.; Di Achille, G.; Ferrari, S.; Giacomini, L.; Popa, C.; Pozzobon, R.; Zusi, M.; Cremonese, G.; Palumbo, P.

    2012-04-01

    Mercury is classically dominated by contractional features at a global scale (e.g. Watters et al.2009, EPSL]). Nonetheless, numerous evidences of strike-slip kinematics have been found on Mercury Dual Imaging System (MDIS) camera images mainly derived from the three MESSENGER flybys and acquired near the terminator. This proves that several lobate scarps and high-relief ridges may be interpreted as transpressional structures more than thrust and back-thrusts systems. This finding may support either tidal despinning or residual mantle convection on ruling the nucleation and development of lobate scarps, although within the general framework of planetary contraction and cooling. In addition, the presence of faults with a clear strike-slip kinematic component may possibly affect future estimates of the hermean radius shortening.

  18. Polymeric nanoparticles for targeted drug delivery system for cancer therapy.

    PubMed

    Masood, Farha

    2016-03-01

    A targeted delivery system based on the polymeric nanoparticles as a drug carrier represents a marvelous avenue for cancer therapy. The pivotal characteristics of this system include biodegradability, biocompatibility, non-toxicity, prolonged circulation and a wide payload spectrum of a therapeutic agent. Other outstanding features are their distinctive size and shape properties for tissue penetration via an active and passive targeting, specific cellular/subcellular trafficking pathways and facile control of cargo release by sophisticated material engineering. In this review, the current implications of encapsulation of anticancer agents within polyhydroxyalkanoates, poly-(lactic-co-glycolic acid) and cyclodextrin based nanoparticles to precisely target the tumor site, i.e., cell, tissue and organ are highlighted. Furthermore, the promising perspectives in this emerging field are discussed. PMID:26706565

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

    SciTech Connect

    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

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

    NASA Astrophysics Data System (ADS)

    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

  1. Multi-Stage System for Automatic Target Recognition

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Lu, Thomas T.; Ye, David; Edens, Weston; Johnson, Oliver

    2010-01-01

    A multi-stage automated target recognition (ATR) system has been designed to perform computer vision tasks with adequate proficiency in mimicking human vision. The system is able to detect, identify, and track targets of interest. Potential regions of interest (ROIs) are first identified by the detection stage using an Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter combined with a wavelet transform. False positives are then eliminated by the verification stage using feature extraction methods in conjunction with neural networks. Feature extraction transforms the ROIs using filtering and binning algorithms to create feature vectors. A feedforward back-propagation neural network (NN) is then trained to classify each feature vector and to remove false positives. The system parameter optimizations process has been developed to adapt to various targets and datasets. The objective was to design an efficient computer vision system that can learn to detect multiple targets in large images with unknown backgrounds. Because the target size is small relative to the image size in this problem, there are many regions of the image that could potentially contain the target. A cursory analysis of every region can be computationally efficient, but may yield too many false positives. On the other hand, a detailed analysis of every region can yield better results, but may be computationally inefficient. The multi-stage ATR system was designed to achieve an optimal balance between accuracy and computational efficiency by incorporating both models. The detection stage first identifies potential ROIs where the target may be present by performing a fast Fourier domain OT-MACH filter-based correlation. Because threshold for this stage is chosen with the goal of detecting all true positives, a number of false positives are also detected as ROIs. The verification stage then transforms the regions of interest into feature space, and eliminates false positives using an

  2. Mercury Emission Measurement at a CFB Plant

    SciTech Connect

    John Pavlish; Jeffrey Thompson; Lucinda Hamre

    2009-02-28

    In response to pending regulation to control mercury emissions in the United States and Canada, several projects have been conducted to perform accurate mass balances at pulverized coal (pc)-fired utilities. Part of the mercury mass balance always includes total gaseous mercury as well as a determination of the speciation of the mercury emissions and a concentration bound to the particulate matter. This information then becomes useful in applying mercury control strategies, since the elemental mercury has traditionally been difficult to control by most technologies. In this instance, oxidation technologies have proven most beneficial for increased capture. Despite many years of mercury measurement and control projects at pc-fired units, far less work has been done on circulating fluidized-bed (CFB) units, which are able to combust a variety of feedstocks, including cofiring coal with biomass. Indeed, these units have proven to be more problematic because it is very difficult to obtain a reliable mercury mass balance. These units tend to have very different temperature profiles than pc-fired utility boilers. The flexibility of CFB units also tends to be an issue when a mercury balance is determined, since the mercury inputs to the system come from the bed material and a variety of fuels, which can have quite variable chemistry, especially for mercury. In addition, as an integral part of the CFB operation, the system employs a feedback loop to circulate the bed material through the combustor and the solids collection system (the primary cyclone), thereby subjecting particulate-bound metals to higher temperatures again. Despite these issues, CFB boilers generally emit very little mercury and show good native capture. The Energy & Environmental Research Center is carrying out this project for Metso Power in order to characterize the fate of mercury across the unit at Rosebud Plant, an industrial user of CFB technology from Metso. Appropriate solids were collected, and

  3. Application of a sorbent trap system to gas-phase elemental and oxidized mercury analysis.

    PubMed

    Zhang, Zishuo; Eom, Yujin; Lee, Michelle J; Lee, Tai Gyu

    2016-07-01

    A sorbent trap that utilizes activated carbon (AC) as the solid trapping medium is a new technology for measuring total mercury (Hg) emissions from combustion facilities. In this study, sorbent trap technology was further developed, improved and evaluated at the laboratory scale. AC was impregnated with 5% aqua regia to enhance its Hg adsorption capacity. Sorbent traps spiked with an Hg standard solution were found to be reproducibly prepared and highly stable. The effect of the Hg concentration on the spiking efficiency was further investigated. The adsorption of elemental and oxidized Hg by the sorbent trap was studied under various experimental conditions (temperature, flow rate and inlet Hg concentration). The Hg concentration of the flue gas effluent from the sorbent trap was measured. In addition, the concentration of Hg adsorbed on the AC was determined by digesting the used AC with an acid according to US EPA method 3052 and then analyzing it with cold vapor atomic absorption spectrometry. Furthermore, the gas-phase Hg emissions from a combustion source were measured using the sorbent trap according to US EPA method 30B. The results showed that the sorbent trap could be used for Hg concentrations between 10.0 and 40.0 μg m(-3) and flow rates between 0.5 and 1.0 lpm with adsorption efficiencies greater than 90%. PMID:27060637

  4. Clapper rails as indicators of mercury and PCB bioavailability in a Georgia saltmarsh system.

    PubMed

    Cumbee, J C; Gaines, K F; Mills, G L; Garvin, N; Stephens, W L; Novak, J M; Brisbin, I L

    2008-08-01

    Clapper rails (Rallus longirostris) were used as an indicator species of estuarine marsh habitat quality because of their strong site fidelity and predictable diet consisting of mostly benthic organisms. Mercury (Hg) and the polychlorinated biphenyl (PCB) Aroclor 1268 concentrations were determined for sediments, crabs, as well as clapper rail adults and chicks collected from salt marshes associated with the LCP Superfund site in Brunswick, Georgia. Home ranges were established for adult rails, and sediment and crab samples were taken from each individual's range. The study was designed to minimize the spatial variability associated with trophic transfer studies by choosing an endpoint species with a potentially small home range and specifically sampling its foraging range. The mean home range for clapper rails was 1.2 ha with a median of 0.28 ha. Concentrations of Hg and Aroclor 1268 were shown to increase with each trophic level. Transfer factors between media followed the same pattern for both contaminants with the highest between fiddler crabs and clapper rail liver. Hg and PCB transfer factors were similar between sediment to fiddler crab and fiddler crab to muscle, however the PCB transfer factor from fiddler crabs to liver was over twice as large as for Hg. PCB congener profiles did not significantly differ between media types. PMID:18389370

  5. Mercury Toolset for Spatiotemporal Metadata

    NASA Technical Reports Server (NTRS)

    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.

  6. Mercury Toolset for Spatiotemporal Metadata

    NASA Astrophysics Data System (ADS)

    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 RESEARCH STRATEGY.

    EPA Science Inventory

    The USEPA's ORD is pleased to announce the availability of its Mercury Research Strategy. This strategy guides ORD's mercury research program and covers the FY2001-2005 time frame. ORD will use it to prepare a multi-year mercury research implementation plan in 2001. The Mercury R...

  8. Mercury contamination extraction

    DOEpatents

    Fuhrmann, Mark; Heiser, John; Kalb, Paul

    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.

  9. Endocannabinoid system: potential novel targets for treatment of schizophrenia

    PubMed Central

    Saito, Atsushi; Ballinger, Michael; Pletnikov, Mikhail V.; Wong, Dean F.; Kamiya, Atsushi

    2013-01-01

    Accumulating epidemiological evidences suggest that cannabis use during adolescence is a potential environmental risk for the development of psychosis, including schizophrenia. Consistently, clinical and preclinical studies, using pharmacological approaches and genetically engineered animals to target endocannabinoid signaling, reveal the multiple varieties of endocannabinoid system-mediated human and animal behaviors, including cognition and emotion. Recently, there has been substantial progress in understanding the molecular mechanisms of the endocannabinoid system for synaptic communications in the central nervous system. Furthermore, the impact of endocannabinoid signaling on diverse cellular processes during brain development has emerged. Thus, although schizophrenia has etiological complexities, including genetic heterogeneities and multiple environmental factors, it now becomes crucial to explore molecular pathways of convergence of genetic risk factors and endocannabinoid signaling, which may provide us with clues to find novel targets for therapeutic intervention. In this review, epidemiological, clinical, and pathological evidences on the role of the endocannabinoid system in the pathophysiologies of schizophrenia will be presented. We will also make a brief overview of the recent progress in understanding molecular mechanisms of the endocannabinoid system for brain development and function, with particular focus on cannabinoid receptor type 1 (CB1R)-mediated cascade, the most well-characterized cannabinoid receptor. Lastly, we will discuss the potential of the endocannabinoid system in finding novel therapeutic targets for prevention and treatment of schizophrenia. PMID:23220619

  10. Current status of JAERI spallation target material program

    NASA Astrophysics Data System (ADS)

    Kikuchi, K.; Sasa, T.; Ishikura, S.; Mukugi, K.; Kai, T.; Ouchi, N.; Ioka, I.

    2001-07-01

    In the joint project of spallation neutron source between JAERI and KEK, material technology has been developed for the mercury target in the neutron source facility, the lead-bismuth target in the transmutation test facility, superconducting accelerator, post-irradiation examination and the ion beam test. Design of target system is progressing for the mercury spallation target: a pressure test of moderator, an impacting test in mercury and a corrosion test have been carried out. For nuclear transmutation with ADS an engineering facility is proposed. A material corrosion test loop is built-up and SS316 and F82H steels are to be tested in a flowing Pb-Bi. Fracture toughness of superconducting cavity material was found to be considerably large at 4 K. Irradiated samples at SINQ are to be transported to JAERI Hot Laboratory. For simulating radiation damage small disk specimens were irradiated in single, dual and triple ion beam modes.

  11. Interactive display system having a scaled virtual target zone

    DOEpatents

    Veligdan, James T.; DeSanto, Leonard

    2006-06-13

    A display system includes a waveguide optical panel having an inlet face and an opposite outlet face. A projector and imaging device cooperate with the panel for projecting a video image thereon. An optical detector bridges at least a portion of the waveguides for detecting a location on the outlet face within a target zone of an inbound light spot. A controller is operatively coupled to the imaging device and detector for displaying a cursor on the outlet face corresponding with the detected location of the spot within the target zone.

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

    SciTech Connect

    Richard Schlager; Tom Millar

    2003-07-01

    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 has an electrostatic

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

    SciTech Connect

    C. Jean Bustard

    2001-07-06

    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

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

    SciTech Connect

    C. Jean Bustard

    2002-01-07

    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 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) coal

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

    SciTech Connect

    Richard Schlager

    2002-04-19

    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 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) coal

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

    SciTech Connect

    C. Jean Bustard

    2001-10-01

    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 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) coal

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

    SciTech Connect

    C. Jean Bustard

    2001-07-31

    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

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

    SciTech Connect

    Jean Bustard; Richard Schlager

    2004-08-03

    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 systems 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 projected DOE/EPA early cost estimates. 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 was 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 injects a dry sorbent, such as activated carbon, which removes the mercury and makes it more susceptible to capture by the particulate control devices. PG&E National Energy Group provided two test sites that fire bituminous coals and both are equipped with electrostatic precipitators and carbon/ash separation systems. Wisconsin Electric Power Company provided a third test site that burns Powder River Basin (PRB) coal and has an electrostatic precipitator for particulate control. Alabama Power Company hosted a fourth test at its Plant Gaston, which is equipped

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

    SciTech Connect

    Jean Bustard; Richard Schlager

    2005-01-03

    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 systems 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 projected DOE/EPA early cost estimates. 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 was 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 injects a dry sorbent, such as activated carbon, which removes the mercury and makes it more susceptible to capture by the particulate control devices. PG&E National Energy Group provided two test sites that fire bituminous coals and both are equipped with electrostatic precipitators and carbon/ash separation systems. Wisconsin Electric Power Company provided a third test site that burns Powder River Basin (PRB) coal and has an electrostatic precipitator for particulate control. Alabama Power Company hosted a fourth test at its Plant Gaston, which is equipped

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

    SciTech Connect

    Richard Schlager; Tom Millar

    2003-04-28

    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 has an electrostatic

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

    SciTech Connect

    Jean Bustard; Richard Schlager

    2004-10-25

    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 systems 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 projected DOE/EPA early cost estimates. 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 was 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 injects a dry sorbent, such as activated carbon, which removes the mercury and makes it more susceptible to capture by the particulate control devices. PG&E National Energy Group provided two test sites that fire bituminous coals and both are equipped with electrostatic precipitators and carbon/ash separation systems. Wisconsin Electric Power Company provided a third test site that burns Powder River Basin (PRB) coal and has an electrostatic precipitator for particulate control. Alabama Power Company hosted a fourth test at its Plant Gaston, which is equipped

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

    SciTech Connect

    Richard Schlager; Tom Millar

    2003-03-02

    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 has an electrostatic

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

    SciTech Connect

    Richard Schlager; Tom Millar

    2003-11-04

    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 has an electrostatic

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

    SciTech Connect

    Jean Bustard

    2004-04-27

    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 systems 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 projected DOE/EPA early cost estimates. 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

  5. Mercury burden and health impairment in dental auxilaries. Final report

    SciTech Connect

    Shapiro, I.M.; Bloch, P.; Ship, I.I.; Spitz, L.; Summer, A.

    1988-01-01

    An effort was made to develop a safe and effective x-ray fluorescence system for monitoring mercury and other elements in human tissues in-situ, to determine mercury levels in 207 dental auxiliaries exposed to dental amalgam on the job, to evaluate mercury in matching nonexposed populations and in 298 dentists using mercury amalgam, and to evaluate deficiencies in central and peripheral nervous systems resulting from the mercury exposure. Mercury levels were below 20 micrograms/gram in 60% of the dentists and 90% of the dental auxiliaries. Dentists with the higher mercury concentrations in their heads or wrists had considerably longer median motor distal latencies and median F-wave latency. Five of them demonstrated abnormalities consistent with carpal tunnel syndrome; seven had polyneuropathies defined as reduced motor or sensory conduction velocities of response amplitudes in two or more nerves. Neuropsychological tests indicated both groups of dental workers were adversely affected by mercury exposure.

  6. A cavity ring-down spectroscopy system for high time resolution measurements of gaseous elemental mercury concentrations

    NASA Astrophysics Data System (ADS)

    Pierce, Ashley M.

    The global cycling of mercury (Hg), a highly toxic environmental pollutant, currently has many unknowns. There are various sources of Hg to the atmosphere including both anthropogenic and natural sources. Processes involved in the global cycling of Hg include emissions from legacy Hg pools, deposition, re-emission, and chemical and physical transformation processes such as gas-phase oxidation and heterogeneous redox reactions. Gaseous elemental mercury (GEM) can represent >95% of Hg present in the atmosphere. GEM has a relatively long atmospheric lifetime, which allows it to be transported 1000s of km, effectively making it a global pollutant. Once deposited, Hg can be converted to methylmercury, a bioavailable form of Hg known to cause neurological damage in wildlife and humans. Current atmospheric Hg sensors require long analyzing periods for a single sample (minutes to hours), thus a faster-response sensor would improve characterization of surface-atmosphere exchange processes and atmospheric Hg dynamics. The goal of this thesis work was to develop a new, field-deployable sensor for high time resolution measurements of GEM in ambient air using pulsed cavity ring-down spectroscopy (CRDS). In this research, a CRDS system was developed using a pulsed laser (50 Hz pulse repetition rate) emitting wavelengths tunable between 215 and 280 nm (Hg absorbs at 253.65 nm), a high finesse 1-m-long cavity lined with two high reflectivity mirrors. Due to the long path length (˜1 km) produced inside the short cavity, sample volumes could be kept small while measurement sensitivity remained high. By optimizing the CRDS setup and reducing interferences (e.g., ozone concentration fluctuations), the current CRDS sensor was deployed in the field to measure GEM concentrations in ambient air. The sensor was also used for the first-ever GEM flux measurements by the eddy covariance flux method. Results showed that fast GEM fluctuations could be detected by the CRDS sensor and the

  7. Mercury, Vaccines, and Autism

    PubMed Central

    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

  8. Generating target system specifications from a domain model using CLIPS

    NASA Technical Reports Server (NTRS)

    Sugumaran, Vijayan; Gomaa, Hassan; Kerschberg, Larry

    1991-01-01

    The quest for reuse in software engineering is still being pursued and researchers are actively investigating the domain modeling approach to software construction. There are several domain modeling efforts reported in the literature and they all agree that the components that are generated from domain modeling are more conducive to reuse. Once a domain model is created, several target systems can be generated by tailoring the domain model or by evolving the domain model and then tailoring it according to the specified requirements. This paper presents the Evolutionary Domain Life Cycle (EDLC) paradigm in which a domain model is created using multiple views, namely, aggregation hierarchy, generalization/specialization hierarchies, object communication diagrams and state transition diagrams. The architecture of the Knowledge Based Requirements Elicitation Tool (KBRET) which is used to generate target system specifications is also presented. The preliminary version of KBRET is implemented in the C Language Integrated Production System (CLIPS).

  9. An airborne real-time hyperspectral target detection system

    NASA Astrophysics Data System (ADS)

    Skauli, Torbjorn; Haavardsholm, Trym V.; Kåsen, Ingebjørg; Arisholm, Gunnar; Kavara, Amela; Opsahl, Thomas Olsvik; Skaugen, Atle

    2010-04-01

    An airborne system for hyperspectral target detection is described. The main sensor is a HySpex pushbroom hyperspectral imager for the visible and near-infrared spectral range with 1600 pixels across track, supplemented by a panchromatic line imager. An optional third sensor can be added, either a SWIR hyperspectral camera or a thermal camera. In real time, the system performs radiometric calibration and georeferencing of the images, followed by image processing for target detection and visualization. The current version of the system implements only spectral anomaly detection, based on normal mixture models. Image processing runs on a PC with a multicore Intel processor and an Nvidia graphics processing unit (GPU). The processing runs in a software framework optimized for large sustained data rates. The platform is a Cessna 172 aircraft based close to FFI, modified with a camera port in the floor.

  10. Study of compact stereoscopic system for target distance estimation

    NASA Astrophysics Data System (ADS)

    Bankman, Daniel J.

    2006-05-01

    Distance measurement is necessary in a variety of fields, including targeting, surveillance, reconnaissance, robotics, and cartography. Today, the most commonly used method for distance measurement is laser ranging. However, laser rangers being active systems require more energy and cost more than passive systems, and they can be detected by the adversary. Stereoscopic vision, a passive system, requires low levels of power and allows covert operation. This study considers stereoscopic vision with a compact, portable system, and investigates its essential parameters that can be optimized for accurate distance measurement. The main parameters addressed in this study are the distance between the two cameras, the kernel size used for correlation between the two images, and the quality of the image measured by the standard deviation of pixel values. The distance estimation accuracy is determined as a function of these parameters and the range to target. To represent a compact, portable system, the study considered parallel camera pairs placed 6 inches or 12 inches apart. Using small, visible light digital cameras, the slant range measurement error is less than 3% with 12 inches camera spacing, and a correlation kernel of 30 pixels in width. Larger camera spacing and shorter ranges to target increase the disparity and decrease the distance estimate error. Analytical error predictions explain the experimental results.

  11. Neural Network Target Identification System for False Alarm Reduction

    NASA Technical Reports Server (NTRS)

    Ye, David; Edens, Weston; Lu, Thomas T.; Chao, Tien-Hsin

    2009-01-01

    A multi-stage automated target recognition (ATR) system has been designed to perform computer vision tasks with adequate proficiency in mimicking human vision. The system is able to detect, identify, and track targets of interest. Potential regions of interest (ROIs) are first identified by the detection stage using an Optimum Trade-off Maximum Average Correlation Height (OT-MACH) filter combined with a wavelet transform. False positives are then eliminated by the verification stage using feature extraction methods in conjunction with neural networks. Feature extraction transforms the ROIs using filtering and binning algorithms to create feature vectors. A feed forward back propagation neural network (NN) is then trained to classify each feature vector and remove false positives. This paper discusses the test of the system performance and parameter optimizations process which adapts the system to various targets and datasets. The test results show that the system was successful in substantially reducing the false positive rate when tested on a sonar image dataset.

  12. ENGINEERING TRADE-OFFS (ETO) INITIATIVE FOR REDUCTION IN MERCURY USE (SYSTEMS ANALYSIS BRANCH, SUSTAINABLE TECHNOLOGY DIVISION,NRMRL)

    EPA Science Inventory

    The demand for mercury in the United States is still growing or declining only slightly in a number of industrial sectors. These include electric lighting, electronic equipment, wiring devices and switches, measurement and control instruments, dental equipment and supplies, labor...

  13. Thermodynamic study of air-cycle and mercury-vapor-cycle systems for refrigerating cooling air for turbines or other components

    NASA Technical Reports Server (NTRS)

    Nachtigall, Alfred J; Freche, John C; Esgar, Jack B

    1956-01-01

    An analysis of air refrigeration systems indicated that air cycles are generally less satisfactory than simple heat exchangers unless high component efficiencies and high values of heat-exchanger effectiveness can be obtained. A system employing a mercury-vapor cycle appears to be feasible for refrigerating air that must enter the system at temperature levels of approximately 1500 degrees R, and this cycle is more efficient than the air cycle. Weight of the systems was not considered. The analysis of the systems is presented in a generalized dimensionless form.

  14. Trojan Binary Asteroid Systems as Future Mission Targets

    NASA Astrophysics Data System (ADS)

    Bellerose, Julie; Yano, Hajime

    To date, the Jupiter-Sun Lagrangian points are populated with almost 4500 asteroids, for which their formation and history are still debated. In the current work, we look at rationales for a mission to Jovian Trojan asteroids, and discuss the scientific benefits to investigate binary systems and contact binary systems. We summarized the dynamics for a solar sail mission, which is currently thought to go along the Europa Jupiter System Mission (EJSM), and we show a case study of the contact binary Hektor, and its moon S/2006, which offer the most suitable conditions for spacecraft operations. Trojans asteroids offer many opportunities, and we list some of the targets in time.

  15. Mercury Quick Facts: Health Effects of Mercury Exposure

    MedlinePlus

    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 ...

  16. Distribution, hydrologic transport, and cycling of total mercury and methyl mercury in a contaminated river-reservoir-wetland system (Sudbury River, eastern Massachusetts)

    USGS Publications Warehouse

    Waldron, M.C.; Colman, J.A.; Breault, R.F.

    2000-01-01

    Riparian wetlands contaminated with Hg from an industrial point source were found to be important sites of production and release of methyl mercury (MeHg) in a 40-km reach of the Sudbury River in eastern Massachusetts. Stream discharge and concentration measurements were used to calculate annual mean loads for total Hg (??Hg) and MeHg in contaminated river reaches, a reservoir, and a riparian wetland downstream from the industrial source. Budgets based on these loads indicate that the annual mean ??Hg load increased sixfold in a reach receiving flow from the point source, but the annual mean MeHg load did not increase. About 23% of the ??Hg load was removed by sedimentation during flow through the reservoir. Net production of MeHg in the reservoir was similar to that reported elsewhere for lakes receiving Hg from atmospheric deposition only. ??Hg concentrations and loads increased significantly as the river passed through the riparian wetland reach. On the basis of flooded wetland area, net production of MeHg was 15 times greater in the wetland reach than in wetland-associated drainages described in other studies.

  17. Theory of Rotation for the Planet Mercury.

    PubMed

    Liu, H S; O'keefe, J A

    1965-12-24

    The theory of the rotation of the planet Mercury is developed in terms of the motion of a rigid system in an inverse-square field. It is possible for Mercury to rotate with a period exactly two-thirds of the period of revolution; there is a libration with a period of 25 years. PMID:17768871

  18. SELECTIVE CATALYTIC REDUCTION MERCURY FIELD SAMPLING PROJECT

    EPA Science Inventory

    The report details an investigation on the effect of selective catalytic reduction (SCR), selective noncatalytic reduction (SNCR), and flue gas conditioning on the speciation and removal of mercury at power plants. If SCR and/or SNCR systems enhance mercury conversion/capture, t...

  19. Increased Mercury Bioaccumulation Follows Water Quality Improvement

    SciTech Connect

    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.

  20. Elemental mercury removal using a wet scrubber.

    SciTech Connect

    Gonzalez, E.; Livengood, C. D.; Martin, K.; Mendelsohn, M. H.; Zhou, C. Q.

    1999-05-19

    Mercury (Hg) is a toxic metal that is emitted into the environment by both natural and human activities. Acute and chronic exposure to mercury and methyl mercury in humans results in central nervous system damage, kidney damage, and even death. Although some Hg emission sources have been regulated, coal-fired utilities have not been. In anticipation of federal regulations on mercury emissions from coal-fired power plants, Argonne National Laboratory (ANL) has designed a flue gas simulation system to study the removal of elemental mercury. The simulated flue gas enters the system and combines with the inlet mercury vapor (from a calibrated permeation tube), carried by nitrogen gas. This combined gas continues past the flow meter and the pressure gage to the reactor inlet. Inside the reactor chamber, the flue gas is sprayed with NOXSORB{reg_sign}, a chloric acid solution, which reacts with elemental mercury. The amount of reaction (oxidation) of elemental mercury is important since mercury in an oxidized form is highly soluble, In this form, the Hg can be picked up downstream by a wet scrubber from fossil-fuel burning utilities. Experiments on mercury removal from flue gases have been conducted at ANL, with the participation of a senior design team from Purdue University Calumet. Temperature variations ranging from room temperature to 350 F have been studied. Other parameters, such as the concentration of NOXSORB{reg_sign}, were also tested. Furthermore, pump speed and sprayer droplet sizes of the NOXSORB{reg_sign} solution were studied. A literature survey on the current and proposed mercury control legislation, along with the existing control technologies, has been performed as part of the senior design project. With guidance from ANL, an understanding of the simulation system has been developed. This information has been used to determine the mass transfer. Another literature survey was performed on the reaction kinetics of mercury. The information obtained was

  1. Phytoremediation of Ionic and Methyl Mercury Pollution

    SciTech Connect

    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

  2. Activation of TRPC cationic channels by mercurial compounds confers the cytotoxicity of mercury exposure.

    PubMed

    Xu, Shang-Zhong; Zeng, Bo; Daskoulidou, Nikoleta; Chen, Gui-Lan; Atkin, Stephen L; Lukhele, Bhekithemba

    2012-01-01

    Mercury is an established worldwide environmental pollutant with well-known toxicity affecting neurodevelopment in humans, but the molecular basis of cytotoxicity and the detoxification procedure are still unclear. Here we examined the involvement of the canonical transient receptor potential (TRPC) channel in the mercury-induced cytotoxicity and the potential detoxification strategy. Whole-cell and excised patches, Ca(2+) imaging, and site-directed mutagenesis were used to determine the mechanism of action of mercurial compounds on TRPC channels overexpressed in HEK293 cells, and cytotoxicity and preventive effect were investigated in cell culture models using small interfering RNA and pharmacological blockers. Mercury potently activates TRPC4 and TRPC5 channels. The extracellular cysteine residues (C(553) and C(558)) near the channel pore region of TRPC5 are the molecular targets for channel activation by mercury. The sensitivity of mercury to TRPC5 is presumed to be specific because other divalent heavy metal pollutants, such as Cd(2+), Ni(2+), and Zn(2+), had no stimulating effect, and TRPC3, TRPC6, TRPV1, and TRPM2 were resistant to mercurial compounds. The channel activity of TRPC5, as well as TRPC4, induced by mercury, was prevented by 2-aminoethoxydiphenyl borate and modified by a reducing environment. The inhibition of TRPC5 channels by specific TRPC5 pore-blocking antibody or by SKF-96365 alleviated the cytotoxicity, whereas the mercury chelator, meso-2,3-dimercaptosuccinic acid, showed nonselective prevention of cell survival. Silencing of the TRPC5 gene reduced the mercury-induced neuronal damage. These results indicate that mercurial compounds are activators for TRPC5 and TRPC4 channels. Blockade of TRPC channels could be a novel strategy for preventing mercury-induced cytotoxicity and neurodevelopment impairment. PMID:21984481

  3. Mercury recycling in the United States in 2000

    USGS Publications Warehouse

    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.

  4. The Endocannabinoid System as a Therapeutic Target in Glaucoma

    PubMed Central

    Cairns, Elizabeth A.; Baldridge, William H.; Kelly, Melanie E. M.

    2016-01-01

    Glaucoma is an irreversible blinding eye disease which produces progressive retinal ganglion cell (RGC) loss. Intraocular pressure (IOP) is currently the only modifiable risk factor, and lowering IOP results in reduced risk of progression of the disorder. The endocannabinoid system (ECS) has attracted considerable attention as a potential target for the treatment of glaucoma, largely due to the observed IOP lowering effects seen after administration of exogenous cannabinoids. However, recent evidence has suggested that modulation of the ECS may also be neuroprotective. This paper will review the use of cannabinoids in glaucoma, presenting pertinent information regarding the pathophysiology of glaucoma and how alterations in cannabinoid signalling may contribute to glaucoma pathology. Additionally, the mechanisms and potential for the use of cannabinoids and other novel agents that target the endocannabinoid system in the treatment of glaucoma will be discussed. PMID:26881140

  5. Elements toward novel therapeutic targeting of the adrenergic system.

    PubMed

    Ghanemi, Abdelaziz; Hu, Xintian

    2015-02-01

    Adrenergic receptors belong to the family of the G protein coupled receptors that represent important targets in the modern pharmacotherapies. Studies on different physiological and pathophysiological properties of the adrenergic system have led to novel evidences and theories that suggest novel possible targeting of such system in a variety of pathologies and disorders, even beyond the classical known therapeutic possibilities. Herein, those advances have been illustrated with selected concepts and different examples. Furthermore, we illustrated the applications and the therapeutic implications that such findings and advances might have in the contexts of experimental pharmacology, therapeutics and clinic. We hope that the content of this work will guide researches devoted to the adrenergic aspects that combine neurosciences with pharmacology. PMID:25481798

  6. Nonimaging active system determination of target shape through turbulent medium

    NASA Astrophysics Data System (ADS)

    Chandler, Susan M.; Lukesh, Gordon W.

    2001-01-01

    Image reconstruction techniques for atmospheric applications often work best with an initial estimate of the object support. This paper examines the ability of a non-imaging laser pointing system to obtain an estimate of target size and shape based on the statistics of the return signal. Fundamental limits on system pointing, such as the tracking errors, corrupt a simple raster scan that would provide gross object shape form the convolution of the far-field pattern with the target. Using techniques developed previously for the estimation of pointing performance, it is possible to distinguish between simple shapes such as bars, circles and T's based on the statistics of the received time signal. Simulated space objects, such as those illuminated during field experiments, may also be distinguished.

  7. The role of the vestibular system in manual target localization

    NASA Technical Reports Server (NTRS)

    Barry, Susan R.; Mueller, S. Alyssa

    1995-01-01

    Astronauts experience perceptual and sensory-motor disturbances during spaceflight and immediately after return to the 1-g environment of Earth. During spaceflight, sensory information from the eyes, limbs and vestibular organs is reinterpreted by the central nervous system so that astronauts can produce appropriate body movements in microgravity. Alterations in sensory-motor function may affect eye-head-hand coordination and, thus, the crewmember's ability to manually locate objects in extrapersonal space. Previous reports have demonstrated that crewmembers have difficulty in estimating joint and limb position and in pointing to memorized target positions on orbit and immediately postflight. One set of internal cues that may assist in the manual localization of objects is information from the vestibular system. This system contributes to our sense of the body's position in space by providing information on head position and movement and the orientation of the body with respect to gravity. Research on the vestibular system has concentrated on its role in oculo-motor control. Little is known about the role that vestibular information plays in manual motor control, such as reaching and pointing movements. Since central interpretation of vestibular information is altered in microgravity, it is important to determine its role in this process. This summer, we determined the importance of vestibular information in a subject's ability to point accurately toward a target in extrapersonal space. Subjects were passively rotated across the earth-vertical axis and then asked to point back to a previously-seen target. In the first paradigm, the subjects used both visual and vestibular cues for the pointing response, while, in the second paradigm, subjects used only vestibular information. Subjects were able to point with 85 percent accuracy to a target using vestibular information alone. We infer from this result that vestibular input plays a role in the spatial programming of

  8. Magnetron co-sputtering system for coating ICF targets

    SciTech Connect

    Hsieh, E.J.; Meyer, S.F.; Halsey, W.G.; Jameson, G.T.; Wittmayer, F.J.

    1981-09-09

    Fabrication of Inertial Confinement Fusion (ICF) targets requires deposition of various types of coatings on microspheres. The mechanical strength, and surface finish of the coatings are of concern in ICF experiments. The tensile strength of coatings can be controlled through grain refinement, selective doping and alloy formation. We have constructed a magnetron co-sputtering system to produce variable density profile coatings with high tensile strength on microspheres.

  9. Targeting bacterial secretion systems: benefits of disarmament in the microcosm.

    PubMed

    Baron, Christian; Coombes, Brian

    2007-03-01

    Secretion systems are used by many bacterial pathogens for the delivery of virulence factors to the extracellular space or directly into host cells. They are attractive targets for the development of novel anti-virulence drugs as their inactivation would lead to pathogen attenuation or avirulence, followed by clearance of the bacteria by the immune system. This review will present the state of knowledge on the assembly and function of type II, type III and type IV secretion systems in Gram-negative bacteria focusing on insights provided by structural analyses of several key components. The suitability of transcription factors regulating the expression of secretion system components and of ATPases, lytic transglycosylases and protein assembly factors as drug targets will be discussed. Recent progress using innovative in vivo as well as in vitro screening strategies led to a first set of secretion system inhibitors with potential for further development as anti-infectives. The discovery of such inhibitors offers exciting and innovative opportunities to further develop these anti-virulence drugs into monotherapy or in combination with classical antibiotics. Bacterial growth per se would not be inhibited by such drugs so that the selection for mutations causing resistance could be reduced. Secretion system inhibitors may therefore avoid many of the problems associated with classical antibiotics and may constitute a valuable addition to our arsenal for the treatment of bacterial infections. PMID:17346208

  10. Microsporidian mitosomes retain elements of the general mitochondrial targeting system

    PubMed Central

    Burri, Lena; Williams, Bryony A. P.; Bursac, Dejan; Lithgow, Trevor; Keeling, Patrick J.

    2006-01-01

    Microsporidia are intracellular parasites that infect a variety of animals, including humans. As highly specialized parasites, they are characterized by a number of unusual adaptations, many of which are manifested as extreme reduction at the molecular, biochemical, and cellular levels. One interesting aspect of reduction is the mitochondrion. Microsporidia were long considered to be amitochondriate, but recently a tiny mitochondrion-derived organelle called the mitosome was detected. The molecular function of this organelle remains poorly understood. The mitosome has no genome, so it must import all its proteins from the cytosol. In other fungi, the mitochondrial protein import machinery consists of a network series of heterooligomeric translocases and peptidases, but in microsporidia, only a few subunits of some of these complexes have been identified to date. Here, we look at targeting sequences of the microsporidian mitosomal import system and show that mitosomes do in some cases still use N-terminal and internal targeting sequences that are recognizable by import systems of mitochondria in yeast. Furthermore, we have examined the function of the inner membrane peptidase processing enzyme and demonstrate that mitosomal substrates of this enzyme are processed to mature proteins in one species with a simplified processing complex, Antonospora locustae. However, in Encephalitozoon cuniculi, the processing complex is lost altogether, and the preprotein substrate functions with the targeting leader still attached. This report provides direct evidence for presequencing processing in mitosomes and also shows how a complex molecular system has continued to degenerate throughout the evolution of microsporidia. PMID:17043242

  11. A Retrieval System for Radioactive Target Materials at the NIF

    NASA Astrophysics Data System (ADS)

    Krieger, M.; Shibata, K.; Fallica, J.; Henchen, R.; Pogozelski, E.; Padalino, S.; Sangster, T. C.; Suny Collaboration; Laboratory Collaboration

    2011-10-01

    Currently, solid radioactive material collection from the NIF target chamber is performed via the DIM. The retrieval process takes several hours to complete. To decrease this time for short lived radioisotopes, the Target Materials Retrieval System (TMRS) is being designed to move a radioactive sample from the target chamber to the counting station in less than 50 seconds, using a closed-loop helium filled RaPToRS system. The TMRS consists of three components: the retrieval apparatus, RaPToRS and the counting station. Starting at 0.5 meters from TCC, the sample will move from the vacuum chamber, travel through 60 meters of 10 centimeter diameter RaPToRS tubes, reaching speeds of 10 m/s. The sample will then arrive at the counting station, where it be robotically placed in front of a gamma ray detector. The use of helium will decrease background gamma radiation produced by activated N2 normally found in a pressurized air system. This work was supported in part by the US Department of Energy through the LLE.

  12. Assessment of End-of-Life Behavior of the Surface Modification to Improve Cavitation-Erosion Resistance in the Mercury Target at the Spallation Neutron Source

    SciTech Connect

    Pawel, Steven J

    2007-06-01

    The cavitation-erosion resistance of the Kolsterised{reg_sign} layer on annealed or cold-worked substrates of 316LN stainless steel has been examined in mercury using a vibratory horn technique and extended exposure periods intended to expose 'end-of-life' performance characteristics. The Kolsterised{reg_sign} layer tends to remain protective--as evidenced by modest steady-state weight loss and surface roughness increases, only isolated pitting, and limited wetting by mercury--until the protective layer has been thinned by general erosion to about 15-20 {micro}m. Prior to that amount of erosion, the cavitation-erosion resistance of both types of specimens appears defined by the properties of the protective layer. However, after thinning to such a degree, initial breakdown of the protective layer is characterized by increases in both the surface roughness and the number/depth of individual pits across the surface at a rate that is strongly dependent on the substrate condition, with annealed substrates significantly more prone to damage. However, even as the protective properties of the Kolsterised{reg_sign} layer decrease, both weight change and profile development as a function of sonication time suggest a gradual reversion to cavitation-erosion behavior similar to that of untreated substrates.

  13. The Vascular System as a Target of Metal Toxicity

    PubMed Central

    Prozialeck, Walter C.; Edwards, Joshua R.; Nebert, Daniel W.; Woods, James M.; Barchowsky, Aaron; Atchison, William D.

    2009-01-01

    Vascular system function involves complex interactions among the vascular endothelium, smooth muscle, the immune system, and the nervous system. The toxic metals cadmium (Cd), arsenic (As), and lead (Pb) can target the vascular system in a variety of ways, ranging from hemorrhagic injury to subtle pathogenic remodeling and metabolic changes. Acute Cd exposure results in hemorrhagic injury to the testis, although some strains of animals are resistant to this effect. A comparison of Cd-sensitive with Cd-resistant mouse strains showed that expression of the Slc39a8 gene, encoding the ZIP8 transporter, in the testis vasculature endothelium is responsible for this difference. Endogenously, ZIP8 is a Mn2+/HCO3−symporter that may also contribute to Cd damage in the kidney. Chronic Cd exposure is associated with various cardiovascular disorders such as hypertension and cardiomyopathy and it is reported to have both carcinogenic and anticarcinogenic activities. At noncytotoxic concentrations of 10–100nM, Cd can inhibit chemotaxis and tube formation of vascular endothelial cells. These angiostatic effects may be mediated through disruption of vascular endothelial cadherin, a Ca2+-dependent cell adhesion molecule. With regard to As, ingestion of water containing disease-promoting concentrations of As promotes capillarization of the liver sinusoidal endothelium. Because capillarization is a hallmark precursor for liver fibrosis and contributes to an imbalance of lipid metabolism, this As effect on hepatic endothelial cells may be a pathogenic mechanism underlying As-related vascular diseases. With regard to Pb, perinatal exposure may cause sustained elevations in adult blood pressure, and genetically susceptible animals may show enhanced sensitivity to this effect. Taken together, these data indicate that the vascular system is a critical target of metal toxicity and that actions of metals on the vascular system may play important roles in mediating the pathophysiologic

  14. EDITORIAL: Mercury-free discharges for lighting

    NASA Astrophysics Data System (ADS)

    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

  15. Transport and accumulation of cesium-137 and mercury in the Clinch River and Watts Bar Reservoir system

    SciTech Connect

    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 {sup 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).

  16. Transport and accumulation of cesium-137 and mercury in the Clinch River and Watts Bar Reservoir system. Environmental Restoration Program

    SciTech Connect

    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 {sup 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).

  17. Mercury concentrations and loads in a large river system tributary to San Francisco Bay, California, U.S.A.

    PubMed

    David, Nicole; McKee, Lester J; Black, Frank J; Flegal, A Russell; Conaway, Christopher H; Schoellhamer, David H; Ganju, Neil K

    2009-10-01

    In order to estimate total mercury (HgT) loads entering San Francisco Bay, U.S.A., via the Sacramento-San Joaquin River system, unfiltered water samples were collected between January 2002 and January 2006 during high flow events and analyzed for HgT. Unfiltered HgT concentrations ranged from 3.2 to 75 ng/L and showed a strong correlation (r2 = 0.8, p < 0.001, n=78) to suspended sediment concentrations (SSC). During infrequent large floods, HgT concentrations relative to SSC were approximately twice as high as observed during smaller floods. This difference indicates the transport of more Hg-contaminated particles during high discharge events. Daily HgT loads in the Sacramento-San Joaquin River at Mallard Island ranged from below the limit of detection to 35 kg. Annual HgT loads varied from 61 +/- 22 kg (n=5) in water year (WY) 2002 to 470 +/- 170 kg (n=25) in WY 2006. The data collected will assist in understanding the long-term recovery of San Francisco Bay from Hg contamination and in implementing the Hg total maximum daily load, the long-term cleanup plan for Hg in the Bay. PMID:19499967

  18. EPA'S OFFICE OF RESEARCH AND DEVELOPMENT PERSPECTIVE ON THE LONG-TERM MANAGEMENT OF EXCESS MERCURY

    EPA Science Inventory

    The Agency is discussing the issues of the long-tem management and retirement of excess mercury. The concept of mercury "retirement" or the long-term management of excess mercury is in its infancy. Currently, the regulatory system supports all mercury recycling initiatives. There...

  19. Regional scale photochemical model evaluation of total mercury wet deposition and speciated ambient mercury

    NASA Astrophysics Data System (ADS)

    Baker, Kirk R.; Bash, Jesse O.

    2012-03-01

    Methylmercury is a known neurotoxin with deleterious health effects on humans and wildlife. Atmospheric deposition is the largest source of mercury loading to most terrestrial and aquatic ecosystems. Regional scale air quality models are needed to quantify mercury deposition resulting from complex emissions sources and physical and chemical processes that govern the fate of mercury in the atmosphere. Total mercury wet deposition estimates from multiple regional photochemical transport models applied at 12 km grid resolution over the continental United States compare well with observations (CAMx fractional error = 45%, CMAQ fractional error = 33%) despite uncertainties in global mercury emissions inventories and certain chemical transformation pathways. In addition, both CMAQ and CAMx well represent observed diel and seasonal patterns of Hg(0) and tend to exaggerate the diel patter of Hg(II) at AMNet monitor locations. The observed fraction of particulate mercury to total oxidized mercury (sum of particulate mercury and Hg(II)) is generally greater in colder months and during overnight hours. The modeling systems tend to capture these patterns but have a systematically lower fraction of particulate mercury to total oxidized mercury, especially in winter months.Annual total mercury deposition from wet and dry processes is 65% greater in CMAQ compared to CAMx over the entire modeling domain. This is largely due to higher wet deposition in CMAQ and higher dry deposition of Hg(0), which is treated as equilibrium with mercury re-emissions and not modeled in CAMx. A sensitivity using CAMx with Hg(0) dry deposition treated similar to CMAQ resulted in more comparable total mercury deposition estimates. Modeled dry deposition velocities for Hg(II) compare well with the limited experimental data, while Hg(0) dry deposition velocities are lower than published experimental data. A mercury bi-directional flux sensitivity application in CMAQ had the overall effect of reducing

  20. Noise Studies of Polarimetry Systems for Polarized 3 He Targets

    NASA Astrophysics Data System (ADS)

    Katugampola, Sumudu K.; Matyas, Daniel J.; Nelyubin, Vladimir; Wang, Yunxiao; Cates, Gordon D.

    2015-04-01

    The NMR technique of adiabatic fast passage (AFP) plays an important role in 3 He targets polarized using spin-exchange optical pumping. Since AFP signals before amplification are generally small, identifying these signals amidst noise caused by external electromagnetic interference and micro-phonics can be challenging. When using thermally polarized water samples for absolute calibration of AFP signals, electromagnetic and micro-phonic noise can easily dominate. Although both types of interference have often been cited as the predominant sources of noise during AFP, few studies of these effects have been done under the conditions that are typical for a polarized 3 He target. This talk will describe studies of electromagnetic and micro-phonic noise using a small-scale prototype NMR system similar to those we use to study polarized 3 He targets. We will describe the effect of using aluminum metal shielding and other methods to minimize noise. We are using these studies to inform the design of a full-scale set up that will be used to test next-generation targets for use at Jefferson Lab, and measure atomic parameters relevant to polarimetry.

  1. DNA repair systems as targets of cadmium toxicity

    SciTech Connect

    Giaginis, Constantinos; Gatzidou, Elisavet; Theocharis, Stamatios . E-mail: theocharis@ath.forthnet.gr

    2006-06-15

    Cadmium (Cd) is a heavy metal and a potent carcinogen implicated in tumor development through occupational and environmental exposure. Recent evidence suggests that proteins participating in the DNA repair systems, especially in excision and mismatch repair, are sensitive targets of Cd toxicit