WorldWideScience

Sample records for suspended inert particles

  1. The Influence of Suspended Inert Solid Particles on Zinc Corrosion

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers

    1996-01-01

    The rate of corrosion of electroplated zinc in near-neutral chloride solutions can be lowered by as much as 75% by adding fine, inert particles of substances such as MnO2, Fe3O4, SiC and TiN to the well-stirred solution. Spreading of local areas of etching is also stopped. Copyright (C) 1996...

  2. Suspending Zeolite Particles In Tanks

    International Nuclear Information System (INIS)

    Poirier, M.R.

    1999-01-01

    The Savannah River Site (SRS) is in the process of removing waste (sludge and salt cake) from million gallon waste tanks. The current practice for removing waste from the tanks is adding water, agitating the tanks with long shaft vertical centrifugal pumps, and pumping the sludge/salt solution from the tank to downstream treatment processes. This practice has left sludge heels (tilde 30,000 gallons) in the bottom of the tanks. SRS is evaluating shrouded axial impeller mixers for removing the sludge heels in the waste tanks. The authors conducted a test program to determine mixer requirements for suspending sludge heels using the shrouded axial impeller mixers. The tests were performed with zeolite in scaled tanks which have diameters of 1.5, 6.0, and 18.75 feet. The mixer speeds required to suspend zeolite particles were measured at each scale. The data were analyzed with various scaling methods to compare their ability to describe the suspension of insoluble solids with the mixers and to apply the data to a full-scale waste tank. The impact of changes in particle properties and operating parameters was also evaluated. The conclusions of the work are: Scaling of the suspension of fast settling zeolite particles was best described by the constant power per unit volume method. Increasing the zeolite particle concentration increased the required mixer power needed to suspend the particles. Decreasing the zeolite particle size from 0.7 mm 0.3 mm decreased the required mixer power needed to suspend the particles. Increasing the number of mixers in the tank decreased the required mixer power needed to suspend the particles. A velocity of 1.6 ft/sec two inches above the tank bottom is needed to suspend zeolite particles

  3. Particles matter: Transformation of suspended particles in constructed wetlands

    NARCIS (Netherlands)

    Mulling, B.T.M.

    2013-01-01

    This thesis shows that constructed wetlands transform suspended particles in (treated) municipal wastewater through selective precipitation in ponds, biological filtering by plankton communities and physical and biological retention in reed beds. These processes effectively remove faecal indicator

  4. Geodetic monitoring of suspended particles in rivers

    Science.gov (United States)

    Kamnik, Rok; Maksimova, Daria; Kovačič, Boštjan

    2017-10-01

    There is a trend in modern approach to the management of space of collecting the spatial data, in order to obtain useful information. In this paper a research of suspended particles in the river Drava and Mura will be introduced. The goal is to connect different fields of water management in countries where the rivers Drava and Mura flows in purpose of water management sustainability. The methods such as GNSS for mapping cross sections of the river, the use of ADCP (Acoustic Doppler Current Profiler) measurement system and water sampling to monitor sediment in the water will be presented.

  5. Elemental compositions of suspended particles released in glass manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Mamuro, T; Mizohata, A; Kubota, T [Radiation Center of Osaka Prefecture, Sakai (Japan)

    1980-03-01

    Suspended particles released in glass manufacture were subjected to multielement analysis by means of instrumental neutron activation method and energy dispersive X-ray fluorescence spectrometry. Suspended particles emitted from glass manufacture generally consist of both particles emitted from glass fusion and those produced through fuel combustion (mainly oil combustion). Elemental compositions of suspended particles emitted from glass fusion were found to be strongly dependent on the kind and recipe of raw materials and additives. Of the various metallic elements involved in suspended particles emitted from glass fusion, the elements, As, Se, Cd, Sb, Pb and so on are regarded to produce the most serious air pollution. The amount of emission of these elements to the environment is, howerer, quite varied from manufacturer to manufacturer. The replacement of electric furnace by oil combustion in opal glass manufacture remarkably reduced the emission of metallic elements to the environment.

  6. A direct simulation method for flows with suspended paramagnetic particles

    NARCIS (Netherlands)

    Kang, T.G.; Hulsen, M.A.; Toonder, den J.M.J.; Anderson, P.D.; Meijer, H.E.H.

    2008-01-01

    A direct numerical simulation method based on the Maxwell stress tensor and a fictitious domain method has been developed to solve flows with suspended paramagnetic particles. The numerical scheme enables us to take into account both hydrodynamic and magnetic interactions between particles in a

  7. Relationship between dioxin concentration and particle size for suspended sediment

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, K.; Sakurai, T.; Choi, J.W.; Suzuki, N.; Morita, M. [National Inst. for Environmental Studies, Tsukuba (Japan)

    2004-09-15

    The purpose of the present study was to find out how the amounts of adsorbed dioxins, i.e., polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/Fs), mono-ortho-polychlorinated biphenyls (PCBs) and non-ortho-PCBs, vary with the particle size of suspended sediment. As dioxins are hydrophobic, they tend to adsorb onto particles suspended in water, and the determination of which dioxin congeners readily dissolve in water or adsorb onto particles is central to the characterization of dioxin behavior in water/sediment systems. Presumably suspension of sediments and the size of the particles govern the transfer of dioxins to aquatic organisms. Therefore, in the present study, we investigated the relationship between the amount of dioxins and the particle-size distribution of resuspended, rather than settled, sediment.

  8. IUTAM symposium on hydrodynamic diffusion of suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.H. [ed.

    1995-12-31

    Hydrodynamic diffusion refers to the fluctuating motion of nonBrownian particles (or droplets or bubbles) which occurs in a dispersion due to multiparticle interactions. For example, in a concentrated sheared suspension, particles do not move along streamlines but instead exhibit fluctuating motions as they tumble around each other. This leads to a net migration of particles down gradients in particle concentration and in shear rate, due to the higher frequency of encounters of a test particle with other particles on the side of the test particle which has higher concentration or shear rate. As another example, suspended particles subject to sedimentation, centrifugation, or fluidization, do not generally move relative to the fluid with a constant velocity, but instead experience diffusion-like fluctuations in velocity due to interactions with neighboring particles and the resulting variation in the microstructure or configuration of the suspended particles. In flowing granular materials, the particles interact through direct collisions or contacts (rather than through the surrounding fluid); these collisions also cause the particles to undergo fluctuating motions characteristic of diffusion processes. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  9. Particles of bottom and suspended sediments: height of rise

    Directory of Open Access Journals (Sweden)

    Khodzinskaya Anna Gennadievna

    2014-12-01

    Full Text Available In the article, characteristic values of dynamic sizes of bottom and suspended sediments, including their probabilistic assessment, are considered. The article presents the processing results in respect of the experimental data for bottom and suspended sediments, obtained in the laboratory environment using samples and filming methods. The experiments have proven that the dynamic hydraulic size determines the height of rise for the particles of the saltation load, rather than suspended ones. In the laboratory environment, the maximal height of rise is mainly driven by the relative flow depth. According to the assessment made by the co-authors, depths of flows employed in the experiments designated for the identification of heights of rises, were comparable to saltation heights of particles. Besides, the saltation height of particles, having relative density well below 2.65, nearly always exceeded half of the depth of the laboratory flow. Hydrodynamic conditions favourable for the separation and motion of artificial particles in coarse surface tanks are far different from the motion of sand particles on the bottom of lowland rivers. Values of hydraulic resistance ratios typical for laboratory experiments by far exceed their values typical for lowland rivers, and it means that the conditions of the experiments performed in the laboratory were similar to those typical for mountain rivers. The research findings have proven that the particle separation and motion pattern, if artificial particles are made of the materials demonstrating variable density and elasticity values and if loose particles travel over fixed ones, is different from the pattern typical for natural particles having variable coarseness.

  10. Multisized Inert Particle Loading for Solid Rocket Axial Combustion Instability Suppression

    Directory of Open Access Journals (Sweden)

    David R. Greatrix

    2012-01-01

    Full Text Available In the present investigation, various factors and trends, related to the usage of two or more sets of inert particles comprised of the same material (nominally aluminum but at different diameters for the suppression of axial shock wave development, are numerically predicted for a composite-propellant cylindrical-grain solid rocket motor. The limit pressure wave magnitudes at a later reference time in a given pulsed firing simulation run are collected for a series of runs at different particle sizes and loading distributions and mapped onto corresponding attenuation trend charts. The inert particles’ presence in the central core flow is demonstrated to be an effective means of instability symptom suppression, in correlating with past experimental successes in the usage of particles. However, the predicted results of this study suggest that one needs to be careful when selecting more than one size of particle for a given motor application.

  11. Drift of suspended ferromagnetic particles due to the Magnus effect

    Science.gov (United States)

    Denisov, S. I.; Pedchenko, B. O.

    2017-01-01

    A minimal system of equations is introduced and applied to study the drift motion of ferromagnetic particles suspended in a viscous fluid and subjected to a time-periodic driving force and a nonuniformly rotating magnetic field. It is demonstrated that the synchronized translational and rotational oscillations of these particles are accompanied by their drift in a preferred direction, which occurs under the action of the Magnus force. We calculate both analytically and numerically the drift velocity of particles characterized by single-domain cores and nonmagnetic shells and show that there are two types of drift, unidirectional and bidirectional, which can be realized in suspensions composed of particles with different core-shell ratios. The possibility of using the phenomenon of bidirectional drift for the separation of core-shell particles in suspensions is also discussed.

  12. Inert gases in a terra sample - Measurements in six grain-size fractions and two single particles from Lunar 20.

    Science.gov (United States)

    Heymann, D.; Lakatos, S.; Walton, J. R.

    1973-01-01

    Review of the results of inert gas measurements performed on six grain-size fractions and two single particles from four samples of Luna 20 material. Presented and discussed data include the inert gas contents, element and isotope systematics, radiation ages, and Ar-36/Ar-40 systematics.

  13. Interactions of radionuclides with sediments and suspended particles

    International Nuclear Information System (INIS)

    Carpenter, R.

    1997-01-01

    This chapter reviews fundamental principles of the rates and extents of radionuclide uptake by sedimentary and suspended particles, defines sediment-water partition coefficients, and shows how they can explain first order features of radionuclide partitioning in aquatic environments. It then explains how sediment accumulation and mixing rates can be calculated from profiles of radionuclide activity measured in sediment cores. Such rates can be combined with profiles of other chemicals to establish the extent of temporal changes in chemical composition of the overlying water body. Since sediment processing and counting in the laboratory take much longer than the time required to collect the sample, suggestions are made to ensure that the sediment samples are not ruined or comprised during collection and handling in the field, and so are worth all the subsequent time and effort to analyze. (author)

  14. Elemental composition of suspended particles released in refuse incineration

    International Nuclear Information System (INIS)

    Mamuro, Tetsuo; Mizohata, Akira

    1979-01-01

    Suspended particles released in refuse incineration were subjected to multielement analysis by means of instrumental neutron activation method and energy dispersive X-ray fluorescence spectrometry. The analytical results were compared with the elemental concentrations observed in the urban atmosphere, and the contribution of the refuse incineration to the urban atmosphere was roughly estimated. Greenberg et al. pointed out on the basis of their analyses that the refuse incineration can account for major portions of the Zn, Cd and Sb observed on urban aerosols. According to our results, the contribution of the refuse incineration for Zn, Cd and Sb is not negligible, but not so serious as in U.S.A. big cities. In Japan big cities there must be other more important sources of these elements. (author)

  15. Labeling suspended aerosol particles with short-lived radionuclides for determination of particle deposition

    International Nuclear Information System (INIS)

    Smith, M.F.; Bryant, S.; Welch, S.; Digenis, G.A.

    1984-01-01

    Radiotracer techniques were developed to examine parameters that characterize pressurized aerosols designed to deliver insoluble particles suspended in the aerosol formulation. Microaggregated bovine serum albumin microspheres that were to be suspended were labeled with iodine-131 (t1/2 . 8 d). This iodination procedure (greater than 80% effective) is also applicable to iodine-123, which possesses superior characteristics for external imaging and further in vivo studies. This report shows that for pressurized aerosols containing suspended particles, each metered dose is approximately equal (not including the priming doses and the emptying doses). Increase in the delivery of the albumin particles out of the canister was best achieved by pretreating the valve assembly with a solution of 2% (w/v) bovine serum albumin in phosphate buffer. Use of a cascade impactor delineated the particle size distribution of the micropheres, with the majority of particles ranging in size from 2 to 8 microns. The data disclosed here indicate that the techniques developed with short-lived radionuclides can be used to quantitate each metered dose, characterize the particle size distribution profile of the aerosol contents, and determine the extent of deposition of the particles in the aerosol canister and all of its components

  16. Suspended particle and drug ingredient concentrations in hospital dispensaries and implications for pharmacists' working environments.

    Science.gov (United States)

    Inaba, Ryoichi; Hioki, Atsushi; Kondo, Yoshihiro; Nakamura, Hiroki; Nakamura, Mitsuhiro

    2016-03-01

    The aim of this study was to assess the present status of working environments for pharmacists, including the concentrations of suspended particles and suspended drug ingredients in dispensaries. We conducted a survey on the work processes and working environment in 15 hospital dispensaries, and measured the concentrations of suspended particles and suspended drug ingredients using digital dust counter and high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. Of 25 types of powdered drugs that were frequently handled in the 15 dispensaries surveyed, 11 could be quantitatively determined. The amounts of suspended particles were relatively high, but below the reference value, in three dispensaries without dust collectors. The sedative-hypnotic drug zopiclone was detected in the suspended particles at one dispensary that was not equipped with dust collectors, and the antipyretic and analgesic drug acetaminophen was detected in two dispensaries equipped with dust collectors. There was no correlation between the daily number of prescriptions containing powdered drugs and the concentration of suspended particles in dispensaries. On the basis of the suspended particle concentrations measured, we concluded that dust collectors were effective in these dispensaries. However, suspended drug ingredients were detected also in dispensaries with dust collectors. These results suggest that the drug dust control systems of individual dispensaries should be properly installed and managed.

  17. Elemental Spatiotemporal Variations of Total Suspended Particles in Jeddah City

    OpenAIRE

    Kadi, Mohammad W.

    2014-01-01

    Elements associated with total suspended particulate matter (TSP) in Jeddah city were determined. Using high-volume samplers, TSP samples were simultaneously collected over a one-year period from seven sampling sites. Samples were analyzed for Al, Ba, Ca, Cu, Mg, Fe, Mn, Zn, Ti, V, Cr, Co, Ni, As, and Sr. Results revealed great dependence of element contents on spatial and temporal variations. Two sites characterized by busy roads, workshops, heavy population, and heavy trucking have high lev...

  18. Motion of Charged Suspended Particle in a Non-Newtonian Fluid between Two Long Parallel Plated

    International Nuclear Information System (INIS)

    Abd-El Khalek, M.M.

    1998-01-01

    The motion of charged suspended particle in a non-Newtonian fluid between two long parallel plates is discussed. The equation of motion of a suspended particle was suggested by Closkin. The equations of motion are reduced to ordinary differential equations by similarity transformations and solved numerically by using the Runge-Kutta method. The trajectories of particles are calculated by integrating the equation of motion of a single particle. The present simulation requires some empirical parameters concerning the collision of the particles with the wall. The effects of solid particles on flow properties are discussed. Some typical results for both fluid and particle phases and density distributions of the particles are presented graphically

  19. Motion of charged suspended particle in a non-Newtonian fluid between two long parallel plates

    Energy Technology Data Exchange (ETDEWEB)

    Abd Elkhalek, M M [Nuclear Research Center-Atomic Energy Authority, Cairo (Egypt)

    1997-12-31

    The motion of charged suspended particle in a non-Newtonian fluid between two long parallel plates is discussed. The equation of motion of a suspended particle was suggested by Closkin. The equations of motion are reduced to ordinary differential equations by similarity transformation and solved numerically by using Runge-Kutta method. The trajectories of particles are calculated by integrating the equation of motion of a single particle. The present simulation requires some empirical parameters concerning the collision of the particles with the wall. The effect of solid particles on flow properties are discussed. Some typical results for both fluid and particle phases and density distributions of the particles are presented graphically. 4 figs.

  20. Suspended particle dynamics and fluxes in an Arctic fjord (Kongsfjorden, Svalbard)

    Science.gov (United States)

    Meslard, Florian; Bourrin, François; Many, Gaël; Kerhervé, Philippe

    2018-05-01

    An experiment was carried out during summer 2015 in the inner part of the Kongsfjorden to study the inputs of meltwater and behaviour of associated suspended particles. We used a wide range of oceanographic instruments to assess the hydrological and hydrodynamic characteristics of coastal waters. The transfer of suspended particles occurs from a large surface plume fed by two main sources: the most important one is the upwelling of fresh and turbid water coming from a tide-water glacier: the Kronebreen, and the second one from a continental glacier: the Kongsvegen. We estimated that these two sources discharged about 2.48 ± 0.37 × 106 t of suspended sediments during the two months of melting. The major part of these sediments is deposited within the first kilometre due to flocculation phenomena. Flocculation is initiated below the surface turbid plume and is mainly caused by the salinity gradient and high suspended particle concentration. Finally, our estimates of suspended particle fluxes by a typical Arctic coastal glacier showed the need to consider suspended sediment fluxes from high-latitude areas into global budgets in the context of climate change.

  1. The magnetic interaction of Janus magnetic particles suspended in a viscous fluid

    NARCIS (Netherlands)

    Seong, Y.; Kang, T.G.; Hulsen, M.A.; den Toonder, J.M.J.; Anderson, P.D.

    2016-01-01

    We studied the magnetic interaction between circular Janus magnetic particles suspended in a Newtonian fluid under the influence of an externally applied uniform magnetic field. The particles are equally compartmentalized into paramagnetic and non-magnetic sides. A direct numerical scheme is

  2. Numerical Simulation of the Motion of Charged Suspended Particle in Multi-Phase Flow

    International Nuclear Information System (INIS)

    Abd-El Khalek, M.M.

    1998-01-01

    A method for computing Numerical simulation of the motion of charged suspended particle in multi-phase flow between two-long parallel plates is described in detail. The equation of motion of a suspended particle was suggested by Closkin. The equations of motion are reduced to ordinary differential equations by similarity transformations and solved numerically by using the Runge-Kutta method. The trajectories of particles are calculated by integrating the equation of motion of a single particle. Numerical solutions of the resulting ordinary differential equations provide velocity distributions for both fluid and solid phases and density distributions for the solid. The present simulation requires some empirical parameters concerning the collision of the particles with the wall. Some typical results for both fluid and particle phases and density distributions of the particles are presented graphically

  3. Numerical simulation of the motion of charged suspended particle in multi-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Abd Elkhalek, M M [Nuclear Research Center-Atomic Energy Authority, Cairo (Egypt)

    1997-12-31

    A method for computing numerical simulation of the motion of charged suspended particle in multi-phase flow between two-long parallel plates is described in detail. The equation of motion of a suspended particle was suggested by closkin. The equations of motion are reduced to ordinary differential equations by similarity transformations and solved numerically by using Runge-Kutta method. The trajectories of particles are calculated by integrating the equation of motion of a single particle. Numerical solutions of the resulting ordinary differential equations provide velocity distributions for both fluid and solid phases and density distributions for the solid. The present simulation requires some empirical parameters concerning the collision of the particles with the wall. Some typical results for both fluid and particle phases and density distributions of the particles are presented graphically. 4 figs.

  4. High temporal resolution in situ measurement of the effective particle size characteristics of fluvial suspended sediment.

    Science.gov (United States)

    Williams, N D; Walling, D E; Leeks, G J L

    2007-03-01

    This paper reports the use of a LISST-100 device to monitor the effective particle size characteristics of suspended sediment in situ, and at a quasi-continuous temporal resolution. The study site was located on the River Exe at Thorverton, Devon, UK. This device has not previously been utilized in studies of fluvial suspended sediment at the storm event scale, and existing studies of suspended sediment dynamics have not involved such a high temporal resolution for extended periods. An evaluation of the field performance of the instrument is presented, with respect to innovative data collection and analysis techniques. It was found that trends in the effective particle size distribution (EPSD) and degree of flocculation of suspended sediment at the study site were highly complex, and showed significant short-term variability that has not previously been documented in the fluvial environment. The collection of detailed records of EPSD facilitated interpretation of the dynamic evolution of the size characteristics of suspended sediment, in relation to its likely source and delivery and flocculation mechanisms. The influence of measurement frequency is considered in terms of its implications for future studies of the particle size of fluvial suspended sediment employing in situ data acquisition.

  5. Total suspended particles (TSP) and breathable particles (PM10) in Aburra Valley, Colombia

    International Nuclear Information System (INIS)

    Saldarriaga Molina, Julio Cesar; Echeverri Londono, Carlos Alberto; Molina Perez Francisco Jose

    2004-01-01

    In the Aburra's valley, nor-western region of Colombia, inhabited by 3 million people, crossed by 400,000 vehicles; with the presence of establishments of industrial sectors: textile, foods and metal-mechanical; The concentrations of total suspended particles (PST) and breathable particles (PM 1 0) were evaluated, during the period: December of 2000 to June of 2001. The determinations of PST and PM 1 0 were performed in ten stations, distributed of north to the south, covering urban and rural zones with the municipalities of: Girardota, Bello, Medellin, Itagui, Sabaneta and Caldas. When analyzing relation PM 1 0/PST, was that the best statistical correlations are located in the zones center and the south of the valley. In addition the increasing tendency in relation PM 1 0/PST was observed, from 0.527 for the rural station Girardota (North), to 0.813 in the urban station Caldas (South). This gradient in relation PM 1 0/PST apparently this related to the wind regime that predominates in the Valley of Aburra with direction the north-south, which causes that the fine particles migrate of north to the south, increasing relation PM 1 0/PST in the same direction

  6. Concentration of aqueous extracts of defatted soy flour by ultrafiltration; Effect of suspended particles on the filtration flux

    NARCIS (Netherlands)

    Noordman, T.R.; Kooiker, K.; Bel, W.; Dekker, M.; Wesselingh, J.A.

    2003-01-01

    Suspended particles can have a positive effect on the flux and concentration curve of soy flour extracts during ultrafiltration. This is described by a simple empirical model. The suspended particles in this study were insoluble milled bean material (mean particle size 25 m). It is shown that it is

  7. The particle size characteristics of fluvial suspended sediment in the Humber and Tweed catchments, UK

    Science.gov (United States)

    Walling; Owens; Waterfall; Leeks; Wass

    2000-05-05

    This paper presents information on the absolute (chemically-dispersed) particle size characteristics of the suspended sediment transported by rivers in the Humber and Tweed basins during the period 1994-1998. For most of the rivers, > 95% of the suspended sediment load at the time of sampling was 63 microm (i.e. sand-sized material). The sediment transported in the two basins were similar. There were, however, noticeable spatial variations in the particle size composition of suspended sediment within the study basins, which reflected the particle size of the sediment sources and their spatial variation, and the selectivity of the sediment mobilization and delivery processes. When particle size parameters were plotted against discharge, there were no significant relationships, although there was some evidence of trends varying between sites. The lack of significant relationships with discharge reflects the fact that sediment particle size is largely supply-controlled, rather than a function of flow and hydraulics. When particle size variations were examined during individual storm events, there was evidence of a pulse of coarse sediment on the rising limb of the hydrograph. This may reflect the remobilization of coarse channel bed sediment as flow velocity and shear stress increase. Finer sediment was transported subsequently during the hydrograph peak and on the falling limb. The findings reported have important implications for understanding and modelling suspended sediment, and associated contaminant, dynamics in river basins.

  8. Laser-induced incandescence of suspended particles as a source of excitation of dye luminescence

    CERN Document Server

    Zelensky, S

    2003-01-01

    The interaction of pulsed YAG-Nd sup 3 sup + laser radiation with submicron light-absorbing particles suspended in an aqueous solution of Rhodamine 6G is investigated experimentally. The experiments demonstrate that the laser-induced incandescence of suspended particles excites the luminescence of the dissolved dye molecules. The mechanism of the luminescence excitation consists in the reabsorption of the thermal radiation within the volume of the sample cell. On the ground of this mechanism of excitation, a method of measurement of the luminescence quantum yield is proposed and realized. The method requires the knowledge of the geometrical parameters of the cell and does not require the use of reference samples.

  9. A method and algorithm for correlating scattered light and suspended particles in polluted water

    International Nuclear Information System (INIS)

    Sami Gumaan Daraigan; Mohd Zubir Matjafri; Khiruddin Abdullah; Azlan Abdul Aziz; Abdul Aziz Tajuddin; Mohd Firdaus Othman

    2005-01-01

    An optical model has been developed for measuring total suspended solids TSS concentrations in water. This approach is based on the characteristics of scattered light from the suspended particles in water samples. An optical sensor system (an active spectrometer) has been developed to correlate pollutant (total suspended solids TSS) concentration and the scattered radiation. Scattered light was measured in terms of the output voltage of the phototransistor of the sensor system. The developed algorithm was used to calculate and estimate the concentrations of the polluted water samples. The proposed algorithm was calibrated using the observed readings. The results display a strong correlation between the radiation values and the total suspended solids concentrations. The proposed system yields a high degree of accuracy with the correlation coefficient (R) of 0.99 and the root mean square error (RMS) of 63.57 mg/l. (Author)

  10. Elemental Spatiotemporal Variations of Total Suspended Particles in Jeddah City

    Directory of Open Access Journals (Sweden)

    Mohammad W. Kadi

    2014-01-01

    Full Text Available Elements associated with total suspended particulate matter (TSP in Jeddah city were determined. Using high-volume samplers, TSP samples were simultaneously collected over a one-year period from seven sampling sites. Samples were analyzed for Al, Ba, Ca, Cu, Mg, Fe, Mn, Zn, Ti, V, Cr, Co, Ni, As, and Sr. Results revealed great dependence of element contents on spatial and temporal variations. Two sites characterized by busy roads, workshops, heavy population, and heavy trucking have high levels of all measured elements. Concentrations of most elements at the two sites exhibit strong spatial gradients and concentrations of elements at these sites are higher than other locations. The highest concentrations of elements were observed during June–August because of dust storms, significant increase in energy consumption, and active surface winds. Enrichment factors of elements at the high-level sites have values in the range >10~60 while for Cu and Zn the enrichment factors are much higher (~0–>700 indicating that greater percentage of TSP composition for these three elements in air comes from anthropogenic activities.

  11. Desorption of radioactive cesium by seawater from the suspended particles in river water.

    Science.gov (United States)

    Onodera, Masaki; Kirishima, Akira; Nagao, Seiya; Takamiya, Kouichi; Ohtsuki, Tsutomu; Akiyama, Daisuke; Sato, Nobuaki

    2017-10-01

    In 2011, the accident at the Fukushima-Daiichi nuclear power plant dispersed radioactive cesium throughout the environment, contaminating the land, rivers, and sea. Suspended particles containing clay minerals are the transportation medium for radioactive cesium from rivers to the ocean because cesium is strongly adsorbed between the layers of clay minerals, forming inner sphere complexes. In this study, the adsorption and desorption behaviors of radioactive cesium from suspended clay particles in river water have been investigated. The radioactive cesium adsorption and desorption experiments were performed with two kinds of suspended particulate using a batch method with 137 Cs tracers. In the cesium adsorption treatment performed before the desorption experiments, simulated river water having a total cesium concentration ([ 133+137 Cs + ] total ) of 1.3 nM (10 -9  mol/L) was used. The desorption experiments were mainly conducted at a solid-to-liquid ratio of 0.17 g/L. The desorption agents were natural seawater collected at 10 km north of the Fukushima-Daiichi nuclear power plant, artificial seawater, solutions of NaCl, KCl, NH 4 Cl, and 133 CsCl, and ultrapure water. The desorption behavior, which depends on the preloaded cesium concentration in the suspended particles, was also investigated. Based on the cesium desorption experiments using suspended particles, which contained about 1000 ng/g loaded cesium, the order of cesium desorption ratios for each desorption agent was determined as 1 M NaCl (80%) > 470 mM NaCl (65%) > 1 M KCl (30%) ≈ seawater (natural seawater and Daigo artificial seawater) > 1 M NH 4 Cl (20%) > 1 M 133 CsCl (15%) ≫ ultrapure water (2%). Moreover, an interesting result was obtained: The desorption ratio in the 470 mM NaCl solution was much higher than that in seawater, even though the Na + concentrations were identical. These results indicate that the cesium desorption mechanism is not a simple ion exchange reaction

  12. Suspended sediment measurements and calculation of the particle load at HPP Fieschertal

    Science.gov (United States)

    Felix, D.; Albayrak, I.; Abgottspon, A.; Boes, R. M.

    2016-11-01

    In the scope of a research project on hydro-abrasive erosion of Pelton turbines, a field study was conducted at the high-head HPP Fieschertal in Valais, Switzerland. The suspended sediment mass concentration (SSC) and particle size distribution (PSD) in the penstock have been continuously measured since 2012 using a combination of six measuring techniques. The SSC was on average 0.52 g/l and rose to 50 g/l in a major flood event in July 2012. The median particle size d 50 was usually 15 pm, rising up to 100 μm when particles previously having settled in the headwater storage tunnel were re-suspended at low water levels. The annual suspended sediment loads (SSL) varied considerably depending on flood events. Moreover, so-called particle loads (PLs) according to the relevant guideline of the International Electrotechnical Commission (IEC 62364) were calculated using four relations between particle size and the relative abrasion potential. For the investigated HPP, the time series of the SSL and the PLs had generally similar shapes over the three years. The largest differences among the PLs were observed during re-suspension events when the particles were considerably coarser than usual. Further investigations on the effects of particle sizes on hydroabrasive erosion of splitters and cut-outs of coated Pelton turbines are recommended.

  13. Cahn-Hilliard modeling of particles suspended in two-phase flows

    NARCIS (Netherlands)

    Choi, Y.J.; Anderson, P.D.

    2012-01-01

    In this paper, we present a model for the dynamics of particles suspended in two-phase flows by coupling the CahnHilliard theory with the extended finite element method (XFEM). In the CahnHilliard model the interface is considered to have a small but finite thickness, which circumvents explicit

  14. Capillary Structured Suspensions from in Situ Hydrophobized Calcium Carbonate Particles Suspended in a Polar Liquid Media

    NARCIS (Netherlands)

    Dunstan, Timothy S.; Das, Anupam A.K.; Starck, Pierre; Stoyanov, Simeon D.; Paunov, Vesselin N.

    2018-01-01

    We demonstrate that capillary suspensions can be formed from hydrophilic calcium carbonate particles suspended in a polar continuous media and connected by capillary bridges formed of minute amounts of an immiscible secondary liquid phase. This was achieved in two different polar continuous phases,

  15. Complete Evaluation of Suspended Air Particles and Their Composition in the Central Area of Yazd City

    Directory of Open Access Journals (Sweden)

    M Younesian

    2009-01-01

    Full Text Available Introduction: Air pollution is one of the problems of the recent century caused by vehicles, industries and other urban activities. The City of Yazd faces air pollution due to its high population, vehicular traffic and industrial places around the city. One of the important parameters of air pollution is suspended air particles that have harmful effects on the health of people, plants and objects. Methods: This research has been carried out by first determining a station in the central area of the city (Shahid Beheshti Square of Yazd. The suspended particles were measured during a five-month period from March to July, 2006. A high volume sampler was used for measuring Total Suspended Particles (TSP. The amount of lead content of TSP was measured in samples by using atomic absorption method. In the next stage, the percentage of organic and inorganic particles in the TSP of all samples was measured by using gravimetric methods and by burning in the oven. Results: The results of this study showed that amount of suspended particles in the city of Yazd is higher than national standard and the general mean average of the suspended particles of air in five months was 233 micrograms per cubic meter. The average concentration of suspended air particles from end of March to August during the five month period was 118, 193, 231, 267and 333, respectively. The average concentration of lead was 0.04 microgram per cubic meter and amount of organic and inorganic particles in TSP was 25.31% and 74.68%, respectively. Conclusion: With respect to the results, the minimum amount of TSP concentration was in March. This could be due to reduction in trading and industrial activities and New Year vacations. In addition, the average monthly TSP increased from March to July; the cause of which could be relative decrease in humidity and increase in temperature. The amount of lead in samples was much less than standard, which could be due to omission of lead from petrol

  16. Tracking suspended particle transport via radium isotopes (226Ra and 228Ra) through the Apalachicola–Chattahoochee–Flint River system

    International Nuclear Information System (INIS)

    Peterson, Richard N.; Burnett, William C.; Opsahl, Stephen P.; Santos, Isaac R.; Misra, Sambuddha; Froelich, Philip N.

    2013-01-01

    Suspended particles in rivers can carry metals, nutrients, and pollutants downstream which can become bioactive in estuaries and coastal marine waters. In river systems with multiple sources of both suspended particles and contamination sources, it is important to assess the hydrologic conditions under which contaminated particles can be delivered to downstream ecosystems. The Apalachicola–Chattahoochee–Flint (ACF) River system in the southeastern United States represents an ideal system to study these hydrologic impacts on particle transport through a heavily-impacted river (the Chattahoochee River) and one much less impacted by anthropogenic activities (the Flint River). We demonstrate here the utility of natural radioisotopes as tracers of suspended particles through the ACF system, where particles contaminated with arsenic (As) and antimony (Sb) have been shown to be contributed from coal-fired power plants along the Chattahoochee River, and have elevated concentrations in the surficial sediments of the Apalachicola Bay Delta. Radium isotopes ( 228 Ra and 226 Ra) on suspended particles should vary throughout the different geologic provinces of this river system, allowing differentiation of the relative contributions of the Chattahoochee and Flint Rivers to the suspended load delivered to Lake Seminole, the Apalachicola River, and ultimately to Apalachicola Bay. We also use various geochemical proxies ( 40 K, organic carbon, and calcium) to assess the relative composition of suspended particles (lithogenic, organic, and carbonate fractions, respectively) under a range of hydrologic conditions. During low (base) flow conditions, the Flint River contributed 70% of the suspended particle load to both the Apalachicola River and the bay, whereas the Chattahoochee River became the dominant source during higher discharge, contributing 80% of the suspended load to the Apalachicola River and 62% of the particles entering the estuary. Neither of these hydrologic

  17. Concentration Measurements of Suspended Load using ADV with Influence of the Particle Size

    Science.gov (United States)

    Schwarzwälder, Kordula

    2017-04-01

    ADV backscatter data can be used under certain conditions to gain information about the concentrations of suspended loads. This was shown in many studies before (Fugate and Friedrichs 2002; Chanson et al 2008; Ha et al. 2009). This paper reports on a pre-study to investigate the influence of particle size on concentration measurements for suspended sediment load with ADV. The study was conducted in a flume in the Oskar-von-Miller-Institute using fresh water from a river including the natural suspended load. The ADV used in the experiments was a Vectrino Profiler (Nortek). In addition water samples were taken for TSS and TOC. For the measurements a surge was generated in the flume to ensure that also particles of larger size will be present in the water phase. The measurements and samples were taken during the whole surge event. Therefore we were able to find a good correlation between the backscatter data of the ADV and the TSS as well as TOC results. For the decreasing part of the flow event the concentration of TOC in the suspended load of the water phase is decreasing much slower than the TSS and results in a damped decrease of the backscatter values. This means that the results for concentration measurements might be slightly influenced by the size of the particles. Further evaluations of measurements conducted with a LISST SL (Sequoia) will be investigated to show the trend of the particle sizes during this process and fortify this result. David C. Fugate, Carl T. Friedrichs, Determining concentration and fall velocity of estuarine particle populations using ADV, OBS and LISST, Continental Shelf Research, Volume 22, Issues 11-13, 2002 H.K. Ha, W.-Y. Hsu, J.P.-Y. Maa, Y.Y. Shao, C.W. Holland, Using ADV backscatter strength for measuring suspended cohesive sediment concentration, Continental Shelf Research, Volume 29, Issue 10, 2009 Hubert Chanson, Maiko Takeuchi, Mark Trevethan, Using turbidity and acoustic backscatter intensity as surrogate measures of

  18. IMPACT OF SIPHONING ACTIVITY AND NATURALLY SUSPENDED PARTICLE LOAD ON MUSSEL KILL by PSEUDOMONAS FLUORESCENS

    International Nuclear Information System (INIS)

    Daniel Molloy

    2003-01-01

    Under this USDOE-NETL contract, the bacterium Pseudomonas fluorescens is being developed as a biocontrol agent for zebra mussels. The specific purpose of the contract is to identify biotic and abiotic factors that affect mussel kill. Ingestion of these bacteria by zebra mussels is required to achieve kill, and tests evaluating factors that relate to mussel feeding are contained in this report. Specifically the impact of the following two factors were investigated: (1) Mussel siphoning behavior--In nature, zebra mussels typically have their two shells spread apart and their inhalant siphon tube extended from between their shells for taking food particles into their mantle cavities (Fig. 1). Our tests indicated that there is a direct correlation between mussel siphoning activity and mussel mortality achieved by a bacterial treatment. Therefore, to encourage mussel feeding on bacteria, future pipe treatments within power plants should be carried out using procedures which minimize disturbance to mussel siphoning. 2. Naturally suspended particle loads--Since bacterial cells are lethal only if ingested by mussels, waters containing very high levels of naturally suspended particles might reduce the mortality that can be achieved by a bacterial treatment. If true, this inhibition might occur as a result of particle exclusion, i.e., there could be reduced ingestion of bacterial cells since they represent a reduced percentage of all particles ingested. Our tests indicated that a range of particle concentrations that might naturally exist in a turbid river did not inhibit mussel kill by the bacterial cells, but that an artificially high load of natural particles was capable of causing a reduction in kill. To be conservative, therefore, future pipe treatments should be timed to occur when intake waters have relatively low quantities of naturally suspended particulate matter

  19. IMPACT OF SIPHONING ACTIVITY AND NATURALLY SUSPENDED PARTICLE LOAD ON MUSSEL KILL by PSEUDOMONAS FLUORESCENS

    Energy Technology Data Exchange (ETDEWEB)

    Daniel Molloy

    2003-08-04

    Under this USDOE-NETL contract, the bacterium Pseudomonas fluorescens is being developed as a biocontrol agent for zebra mussels. The specific purpose of the contract is to identify biotic and abiotic factors that affect mussel kill. Ingestion of these bacteria by zebra mussels is required to achieve kill, and tests evaluating factors that relate to mussel feeding are contained in this report. Specifically the impact of the following two factors were investigated: (1) Mussel siphoning behavior--In nature, zebra mussels typically have their two shells spread apart and their inhalant siphon tube extended from between their shells for taking food particles into their mantle cavities (Fig. 1). Our tests indicated that there is a direct correlation between mussel siphoning activity and mussel mortality achieved by a bacterial treatment. Therefore, to encourage mussel feeding on bacteria, future pipe treatments within power plants should be carried out using procedures which minimize disturbance to mussel siphoning. 2. Naturally suspended particle loads--Since bacterial cells are lethal only if ingested by mussels, waters containing very high levels of naturally suspended particles might reduce the mortality that can be achieved by a bacterial treatment. If true, this inhibition might occur as a result of particle exclusion, i.e., there could be reduced ingestion of bacterial cells since they represent a reduced percentage of all particles ingested. Our tests indicated that a range of particle concentrations that might naturally exist in a turbid river did not inhibit mussel kill by the bacterial cells, but that an artificially high load of natural particles was capable of causing a reduction in kill. To be conservative, therefore, future pipe treatments should be timed to occur when intake waters have relatively low quantities of naturally suspended particulate matter.

  20. Transfer of suspended particles from liquid effluents of nuclear generating stations through the environment

    International Nuclear Information System (INIS)

    Devereaux, F.J.

    1989-07-01

    Due to the complexity of the environmental transfer of suspended particles in aquatic systems, the available literature usually deals with specific pathways and mechanisms of the transfer process. This paper attempts to give a brief overview of the entire transfer process. Potential routes of transfer in both the marine and freshwater environments are examined, and tentative conclusions presented. This work was performed while the author was employed by Atomic Energy Control Board under the McMaster University cooperative program

  1. Deciphering the science behind electrocoagulation to remove suspended clay particles from water.

    Science.gov (United States)

    Holt, P K; Barton, G W; Mitchell, C A

    2004-01-01

    Electrocoagulation removes pollutant material from water by a combination of coagulant delivered from a sacrificial aluminium anode and hydrogen bubbles evolved at an inert cathode. Rates of clay particle flotation and settling were experimentally determined in a 7 L batch reactor over a range of currents (0.25-2.0 A) and pollutant loadings (0.1-1.7 g/L). Sedimentation and flotation are the dominant removal mechanism at low and high currents, respectively. This shift in separation mode can be explained by analysing the reactor in terms of a published dissolved air flotation model.

  2. A suspended-particle rosette multi-sampler for discrete biogeochemical sampling in low-particle-density waters

    Energy Technology Data Exchange (ETDEWEB)

    Breier, J. A.; Rauch, C. G.; McCartney, K.; Toner, B. M.; Fakra, S. C.; White, S. N.; German, C. R.

    2010-06-22

    To enable detailed investigations of early stage hydrothermal plume formation and abiotic and biotic plume processes we developed a new oceanographic tool. The Suspended Particulate Rosette sampling system has been designed to collect geochemical and microbial samples from the rising portion of deep-sea hydrothermal plumes. It can be deployed on a remotely operated vehicle for sampling rising plumes, on a wire-deployed water rosette for spatially discrete sampling of non-buoyant hydrothermal plumes, or on a fixed mooring in a hydrothermal vent field for time series sampling. It has performed successfully during both its first mooring deployment at the East Pacific Rise and its first remotely-operated vehicle deployments along the Mid-Atlantic Ridge. It is currently capable of rapidly filtering 24 discrete large-water-volume samples (30-100 L per sample) for suspended particles during a single deployment (e.g. >90 L per sample at 4-7 L per minute through 1 {mu}m pore diameter polycarbonate filters). The Suspended Particulate Rosette sampler has been designed with a long-term goal of seafloor observatory deployments, where it can be used to collect samples in response to tectonic or other events. It is compatible with in situ optical sensors, such as laser Raman or visible reflectance spectroscopy systems, enabling in situ particle analysis immediately after sample collection and before the particles alter or degrade.

  3. Heavy metal toxicity and bioavailability of dissolved nutrients to a bacterivorous flagellate are linked to suspended particle physical properties

    International Nuclear Information System (INIS)

    Boenigk, Jens; Wiedlroither, Anneliese; Pfandl, Karin

    2005-01-01

    Many dissolved substances attach easily to sediment particles. In the presence of suspended sediments bioavailability of dissolved substances is therefore, usually reduced and clays are even applied to 'wash' natural waters upon pollution. In organisms which feed on food organisms in the size range of these suspended sediment particles, however, bioavailability of such substances may even increase. For microorganisms the interaction with dissolved substances and suspended sediment particles so far has hardly been investigated. We specifically tested: (1) the importance of suspended particles as an uptake route for dissolved substances; and (2) the significance of particle surface properties, i.e. surface load and mineralogy. As a model system we used an axenically cultured strain of a widespread and often abundant flagellate ('Spumella-like' flagellate strain JBM10). We tested the toxicity of cadmium (II) and mercury (II) as well as availability of dissolved organic matter (DOM) in the absence as well as in the presence of different natural clays, i.e. a kaolinite, a montmorillonite, and a mixed clay, and of artificial silicate particles of different surface charge. When applied separately the presence of the heavy metals cadmium and mercury as well as of suspended particles negatively affected the investigated flagellate but nutritive organics supported growth of the investigated flagellate. Toxic stress response comprises behavioral changes including enhanced swimming activity and stress egestion of ingested particles and was generally similar for a variety of different flagellate species. In combination with suspended particles, the respective effect of trace metals and nutritive substances decreased. Regarding the particle quality, cadmium toxicity increased with increasingly negative surface charge, i.e. increasing surface density of silanol groups (Pearson's product moment, P = 0.005). For mercury particle mineralogy still had a significant effect (P < 0

  4. Effect of sonication on particle dispersion, administered dose and metal release of non-functionalized, non-inert metal nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Sulena; Hedberg, Jonas, E-mail: jhed@kth.se; Blomberg, Eva [KTH Royal Institute of Technology, Division of Surface and Corrosion Science, Department of Chemistry (Sweden); Wold, Susanna [KTH Royal Institute of Technology, Division of Applied Physical Chemistry, Department of Chemistry (Sweden); Odnevall Wallinder, Inger [KTH Royal Institute of Technology, Division of Surface and Corrosion Science, Department of Chemistry (Sweden)

    2016-09-15

    In this study, we elucidate the effect of different sonication techniques to efficiently prepare particle dispersions from selected non-functionalized NPs (Cu, Al, Mn, ZnO), and corresponding consequences on the particle dose, surface charge and release of metals. Probe sonication was shown to be the preferred method for dispersing non-inert, non-functionalized metal NPs (Cu, Mn, Al). However, rapid sedimentation during sonication resulted in differences between the real and the administered doses in the order of 30–80 % when sonicating in 1 and 2.56 g/L NP stock solutions. After sonication, extensive agglomeration of the metal NPs resulted in rapid sedimentation of all particles. DLVO calculations supported these findings, showing the strong van der Waals forces of the metal NPs to result in significant NP agglomeration. Metal release from the metal NPs was slightly increased by increased sonication. The addition of a stabilizing agent (bovine serum albumin) had an accelerating effect on the release of metals in sonicated solutions. For Cu and Mn NPs, the extent of particle dissolution increased from <1.6 to ~5 % after sonication for 15 min. A prolonged sonication time (3–15 min) had negligible effects on the zeta potential of the studied NPs. In all, it is shown that it is of utmost importance to carefully investigate how sonication influences the physico-chemical properties of dispersed metal NPs. This should be considered in nanotoxicology investigations of metal NPs.Graphical Abstract.

  5. Motion of a suspended charged particle in a NON-Newtonian fluid. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Khalek, M M [Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    The path lines of a solid spherical charged particle suspended in a non-newton electrical conducting viscous fluid through two infinite parallel plates in the presence of a constant magnetic field normal to the plane of particle motion were determined. The effect of some parameters such as particle volume, fluid density, fluid viscosity, and the use magnetic field strength on these path lines were determined. The present solution requires some empirical parameters concerning the collision of the particles with the wall. The differential equations of motion were numerically solved by Runge-Kutta method. Some conclusions about width, maximum height and number of collisions with upper and lower plates were deduced. 4 figs.

  6. Flow regime and deposition pattern of evaporating binary mixture droplet suspended with particles.

    Science.gov (United States)

    Zhong, Xin; Duan, Fei

    2016-02-01

    The flow regimes and the deposition pattern have been investigated by changing the ethanol concentration in a water-based binary mixture droplet suspended with alumina nanoparticles. To visualize the flow patterns, Particle Image Velocimetry (PIV) has been applied in the binary liquid droplet containing the fluorescent microspheres. Three distinct flow regimes have been revealed in the evaporation. In Regime I, the vortices and chaotic flows are found to carry the particles to the liquid-vapor interface and to promote the formation of particle aggregation. The aggregates move inwards in Regime II as induced by the Marangoni flow along the droplet free surface. Regime III is dominated by the drying of the left water and the capillary flow driving particles radially outward is observed. The relative weightings of Regimes I and II, which are enhanced with an increasing load of ethanol, determine the motion of the nanoparticles and the formation of the final drying pattern.

  7. Modeled heating and surface erosion comparing motile (gas borne) and stationary (surface coating) inert particle additives

    International Nuclear Information System (INIS)

    Buckingham, A.C.; Siekhaus, W.J.

    1982-01-01

    The unsteady, non-similar, chemically reactive, turbulent boundary layer equations are modified for gas plus dispersed solid particle mixtures, for gas phase turbulent combustion reactions and for heterogeneous gas-solid surface erosive reactions. The exterior (ballistic core) edge boundary conditions for the solutions are modified to include dispersed particle influences on core propellant combustion-generated turbulence levels, combustion reactants and products, and reaction-induced, non-isentropic mixture states. The wall surface (in this study it is always steel) is considered either bare or coated with a fixed particle coating which is conceptually non-reactive, insulative, and non-ablative. Two families of solutions are compared. These correspond to: (1) consideration of gas-borne, free-slip, almost spontaneously mobile (motile) solid particle additives which influence the turbulent heat transfer at the uncoated steel surface and, in contrast, (2) consideration of particle-free, gas phase turbulent heat transfer to the insulated surface coated by stationary particles. Significant differences in erosive heat transfer are found in comparing the two families of solutions over a substantial range of interior ballistic flow conditions. The most effective influences on reducing erosive heat transfer appear to favor mobile, gas-borne particle additives

  8. Assessment of the Atmospheric Suspended Particles Pollution in the Madrid Air Quality Networks

    International Nuclear Information System (INIS)

    Salvador, P.; Artinano, B.

    2000-01-01

    Suspended particles are a very complex type of atmospheric pollution because of their chemical composition and size. In fact, there are a quite high number of particles sources which are linked to different physicochemical processes that determine their size. At present particles smaller than 10 μm are considered the most dangerous, as has been recently pointed out by numerous epidemiologic studies. In this way, more restrictive concentration limit values have been approved in the EU countries, so an assessment of present airborne concentration values and the sources apportionment in their most representative areas is needed. In the Madrid Community a first approaching of these and other aims, has been carried out from an analysis of the Madrid Air Quality networks data. This will contribute to the establishment of concentration levels abatement strategies. (Author) 111 refs

  9. A flowrate measurement method by counting of radioactive particles suspended in a liquid

    International Nuclear Information System (INIS)

    Daniel, G.

    1983-04-01

    By external counting of fine #betta# emitting radioactive particles suspended in a liquid, the flowrate in a system of pipes can be measured. The study comprises three phases: 1. - The hydraulic validity of the method is demonstrated in laminar as well as in turbulent flow under certain conditions of particles size and density and of liquid viscosity. 2. - Radioactive labelling of microspheres of serumalbumin or ion exchange resins with indium 113m delivered by a generator Tin 113 → Indium 113m. 3. - Counting with a scintillation detector: a method of threshold overstepping is experimented with a mechanical or electronic simulator; the statistical study of particle superposition under the detector enables a correction for the resulting counting losses to be proposed. The method provides absolute measurements, but is particularly suitable to measure relative flowrates in a hydraulic network. It can be continuous and does not perturb the flow and the network. The accuracy of the method is analysed in details [fr

  10. Momentum, heat, and mass transfer analogy for vertical hydraulic transport of inert particles

    Directory of Open Access Journals (Sweden)

    Jaćimovski Darko R.

    2014-01-01

    Full Text Available Wall-to-bed momentum, heat and mass transfer in vertical liquid-solids flow, as well as in single phase flow, were studied. The aim of this investigation was to establish the analogy among those phenomena. Also, effect of particles concentration on momentum, heat and mass transfer was studied. The experiments in hydraulic transport were performed in a 25.4 mm I.D. cooper tube equipped with a steam jacket, using spherical glass particles of 1.94 mm in diameter and water as a transport fluid. The segment of the transport tube used for mass transfer measurements was inside coated with benzoic acid. In the hydraulic transport two characteristic flow regimes were observed: turbulent and parallel particle flow regime. The transition between two characteristic regimes (γ*=0, occurs at a critical voidage ε≈0.85. The vertical two-phase flow was considered as the pseudofluid, and modified mixture-wall friction coefficient (fw and modified mixture Reynolds number (Rem were introduced for explanation of this system. Experimental data show that the wall-to-bed momentum, heat and mass transfer coefficients, in vertical flow of pseudofluid, for the turbulent regime are significantly higher than in parallel regime. Wall-to-bed, mass and heat transfer coefficients in hydraulic transport of particles were much higher then in single-phase flow for lower Reynolds numbers (Re15000, there was not significant difference. The experimental data for wall-to-bed momentum, heat and mass transfer in vertical flow of pseudofluid in parallel particle flow regime, show existing analogy among these three phenomena. [Projekat Ministarstva nauke Republike Srbije, br. 172022

  11. Characterization of the compounds of nitrogen and total suspended particles in the municipality Regla, Havana

    International Nuclear Information System (INIS)

    Wallo Vazquez, Antonio; Cuesta Santos, Osvaldo

    2006-01-01

    The questions related with the atmospheric contamination in urban areas every day they charge bigger importance for the affectations that it can take place so much in the health of the human beings as in the materials, constructions, etc. In the city of Havana those made up of nitrogen and the particles suspended totals are of the pollutants whose concentrations are elevated in the atmosphere. Inside this context, the present work intends the analysis of the behavior of this concentrations, taken as experimental polygon the municipality Regla in city of Havana

  12. Effects of transparent exopolymer particles and suspended particles on the survival of Salmonella enterica serovar Typhimurium in seawater.

    Science.gov (United States)

    Davidson, Marion C F; Berardi, Terra; Aguilar, Beatriz; Byrne, Barbara A; Shapiro, Karen

    2015-03-01

    The bacterium Salmonella enterica can infect marine mammals and has been increasingly implicated in seafood-borne disease outbreaks in humans. Despite the risk this zoonotic agent poses to animals and people, little is known regarding the environmental factors that affect its persistence in the sea. The goal of this study was to evaluate the impact of two constituents on the survival of Salmonella in the marine environment: transparent exopolymer particles (TEP) and suspended particles. A decay experiment was conducted by spiking Salmonella into bottles containing seawater, seawater with alginic acid as a source of TEP, filtered seawater or filtered seawater with alginic acid. Survival of Salmonella was monitored using culture followed by enrichment assays to evaluate if the bacteria entered a viable but non-cultivable (VBNC) state. Salmonella cell counts dropped significantly faster (P ≤ 0.05) in the unfiltered seawater samples with and without TEP. The slowest decay occurred in filtered seawater containing alginic acid, with VBNC Salmonella persisting for 17 months. These findings suggest that TEP may favor Salmonella survival while suspended particles facilitate its decay. Insight on the survival of allochthonous, zoonotic pathogens in seawater can guide monitoring, management and policy decisions relevant to wildlife and human public health. © FEMS 2015. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. Trace element contents in atmospheric suspended particles: inferences from instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Querol, X.; Alastuey, A.; Lopez-Soler, A.; Boix, A.; Sanfeliu, T.; Martynov, V.V.; Piven, P.I.; Kabina, L.P.; Souschov, P.A.

    1997-01-01

    This study focuses on the determination of trace element concentrations in total suspended particles by instrumental neutron activation analysis (INAA) in two different areas in Northeastern Spain (a rural area influenced by the emissions of a large coal-fired power station, and the urban and industrial areas of Castellon). Total suspended particles were sampled by means of standard MCV high- and medium-volume captors, using cellulose membrane filters of 0.8 and 0.45 μm pore size. Preliminary research was performed on the homogeneous distribution of elements in the sample filters and on the study of blank filters for the calculations of the background average element contents. The results obtained allowed to distinguish different major anthropogenic sources of trace elements in the atmosphere at the sampling sites: (a) Zr, Hf, Sc, U and Th are related to atmospheric pollution derived from the ceramic industry of the Castellon area; (b) As, Cr, Cs, Rb, Sb, Se, Zn are related to traffic and other industrial emission in the Castellon area, and As, Cr, Sb and Zn to power generation emissions in the rural area. (orig.). With 3 figs., 5 tabs

  14. Dynamics of suspended sediment concentration, flow discharge and sediment particle size interdependency to identify sediment source

    Science.gov (United States)

    Sadeghi, Seyed Hamidreza; Singh, Vijay P.

    2017-11-01

    Spatiotemporal behavior of sediment yield is a key for proper watershed management. This study analyzed statistical characteristics and trends of suspended sediment concentration (SCS), flow discharge (FD) and sediment particle sizes using data from 24 gage stations scattered throughout the United States. Analysis showed significant time- and location-specific differences of these variables. The median values of SSC, FD and percentage of particle sizes smaller than 63 μm (P63) for all 24 gage stations were found to be 510.236 mg l-1 (right skewed), 45.406 m3 s-1 (left skewed) and 78.648% (right skewed), respectively. Most of the stations exhibited significant trends (P practices which may call for local or regional planning based on natural (i.e., precipitation amount, type and erosivity, watershed area, and soil erodibility) and human-affected (i.e., land use and hydraulic structures and water resources management) factors governing the study variables.

  15. Ultrasonic device for real-time sewage velocity and suspended particles concentration measurements.

    Science.gov (United States)

    Abda, F; Azbaid, A; Ensminger, D; Fischer, S; François, P; Schmitt, P; Pallarès, A

    2009-01-01

    In the frame of a technological research and innovation network in water and environment technologies (RITEAU, Réseau de Recherche et d'Innovation Technologique Eau et Environnement), our research group, in collaboration with industrial partners and other research institutions, has been in charge of the development of a suitable flowmeter: an ultrasonic device measuring simultaneously the water flow and the concentration of size classes of suspended particles. Working on the pulsed ultrasound principle, our multi-frequency device (1 to 14 MHz) allows flow velocity and water height measurement and estimation of suspended solids concentration. Velocity measurements rely on the coherent Doppler principle. A self developed frequency estimator, so called Spectral Identification method, was used and compared to the classical Pulse-Pair method. Several measurements campaigns on one wastewater collector of the French city of Strasbourg gave very satisfactory results and showed smaller standard deviation values for the Doppler frequency extracted by the Spectral Identification method. A specific algorithm was also developed for the water height measurements. It relies on the water surface acoustic impedance rupture and its peak localisation and behaviour in the collected backscattering data. This algorithm was positively tested on long time measurements on the same wastewater collector. A large part of the article is devoted to the measurements of the suspended solids concentrations. Our data analysis consists in the adaptation of the well described acoustic behaviour of sand to the behaviour of wastewater particles. Both acoustic attenuation and acoustic backscattering data over multiple frequencies are analyzed for the extrapolation of size classes and respective concentrations. Under dry weather conditions, the massic backscattering coefficient and the overall size distribution showed similar evolution whatever the measurement site was and were suggesting a global

  16. Characterisation of a re-cast composite Nafion 1100 series of proton exchange membranes incorporating inert inorganic oxide particles

    International Nuclear Information System (INIS)

    Slade, S.M.; Smith, J.R.; Campbell, S.A.; Ralph, T.R.; Ponce de Leon, C.; Walsh, F.C.

    2010-01-01

    A series of cation exchange membranes was produced by impregnating and coating both sides of a quartz web with a Nafion solution (1100 EW, 10%wt in water). Inert filler particles (SiO 2 , ZrO 2 or TiO 2 ; 5-20%wt) were incorporated into the aqueous Nafion solution to produce robust, composite membranes. Ion-exchange capacity/equivalent weight, water take-up, thickness change on hydration and ionic and electrical conductivity were measured in 1 mol dm -3 sulfuric acid at 298 K. The TiO 2 filler significantly impacted on these properties, producing higher water take-up and increased conductivity. Such membranes may be beneficial for proton exchange membrane (PEM) fuel cell operation at low humidification. The PEM fuel cell performance of the composite membranes containing SiO 2 fillers was examined in a Ballard Mark 5E unit cell. While the use of composite membranes offers a cost reduction, the unit cell performance was reduced, in practice, due to drying of the ionomer at the cathode.

  17. Escoabilidade de leitos de partículas inertes com polpa de frutas tropicais: efeitos na secagem em leito de jorro Flowability of inert particle beds with fruit pulp: effects on the drying in spouted bed

    Directory of Open Access Journals (Sweden)

    Maria de F. D. de Medeiros

    2001-12-01

    Full Text Available Neste trabalho, foram caracterizados seis tipos de material inerte, utilizados na secagem de polpa de frutas em leito de jorro. Determinou-se o ângulo de repouso das partículas, com e sem adição de água e de polpa de diversas frutas tropicais. Correlacionou-se a escoabilidade com as propriedades das partículas e com a composição química das polpas. Analisou-se a influência do ângulo de repouso sobre o desempenho do secador, no que se refere à produção. Os resultados mostraram que, em geral, as polpas com elevadas concentrações de gordura e sólidos insolúveis e baixos teores de açúcares redutores, facilitam a escoabilidade. Uma análise dos resultados obtidos na secagem de polpa de frutas tropicais, utilizando-se partículas de poliestireno de baixa densidade, como material inerte, mostrou que, embora a escoabilidade permita a obtenção de menores vazões de jorro mínimo, em relação ao desempenho do secador, pode não favorecer uma produção maior de pó.In this work six types of inert particles were characterized and analyzed for drying tropical fruit pulps. The repose angle was determined with and without the addition of water and pulp of various tropical fruits. The bed flowability was related to the particle properties and chemical composition of pulps. The influence of the repose angle on the drying performance was analyzed. It was also verified that the composition of pulps influenced the bed flowability. The global analysis showed that the pulps with high lipids and insoluble solids content and low reducing sugar content improved the bed flowability. The results obtained with the drying of the fruit pulps using low-density polystyrene granules as inert particles showed that high flowabilities lead to lower minimum spout flow rates, but do not necessarily lead to the highest powder production.

  18. Hysteresis in suspended sediment to turbidity relations due to changing particle size distributions

    Science.gov (United States)

    Landers, Mark N.; Sturm, Terry W.

    2013-01-01

    Turbidity (T) is the most ubiquitous of surrogate technologies used to estimate suspended-sediment concentration (SSC). The effects of sediment size on turbidity are well documented; however, effects from changes in particle size distributions (PSD) are rarely evaluated. Hysteresis in relations of SSC-to-turbidity (SSC~T) for single stormflow events was observed and quantified for a data set of 195 concurrent measurements of SSC, turbidity, discharge, velocity, and volumetric PSD collected during five stormflows in 2009–2010 on Yellow River at Gees Mill Road in metropolitan Atlanta, Georgia. Regressions of SSC-normalized turbidity (T/SSC) on concurrently measured PSD percentiles show an inverse, exponential influence of particle size on turbidity that is not constant across the size range of the PSD. The majority of the influence of PSD on T/SSC is from particles of fine-silt and smaller sizes (finer than 16 microns). This study shows that small changes in the often assumed stability of the PSD are significant to SSC~T relations. Changes of only 5 microns in the fine silt and smaller size fractions of suspended sediment PSD can produce hysteresis in the SSC~T rating that can increase error and produce bias. Observed SSC~T hysteresis may be an indicator of changes in sediment properties during stormflows and of potential changes in sediment sources. Trends in the PSD time series indicate that sediment transport is capacity-limited for sand-sized sediment in the channel and supply-limited for fine silt and smaller sediment from the hillslope.

  19. Numerical analysis of the motion of a suspended charged particle in multi-phase flow. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    El-khalek, M M [Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    The motion of a suspended charged particle in a two component viscous fluid through two infinite parallel plates was studied. The motion takes place under constant magnetic field normal to the plane of the motion. The effect of some parameters as particle volume, fluid density, viscosity of the fluid, and the magnetic force used on the motion were investigated. The particle is assumed moving initially from the midpoint of the channel with a velocity equal to the velocity of the fluid. The trajectory of solid spherical suspended charged particle is calculated by integrating the equations of motion of a single particle. The present simulation requires some empirical parameters concerning the collision of the particles with the wall. The differential equations of motion were numerically solved by Runge-Kutta method. Some conclusions about the path lines were deduced. 5 figs.

  20. Relationship between particle size and radiocesium in fluvial suspended sediment related to the Fukushima Daiichi Nuclear Power Plant accident

    International Nuclear Information System (INIS)

    Kazuya Tanaka

    2014-01-01

    We collected fluvial suspended sediments in Fukushima after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident and analyzed the 137 Cs concentration in bulk and size-fractioned samples to investigate the particle-size-dependent distribution of radiocesium. The 137 Cs concentration in bulk suspended sediments decreased from August to December 2011, possibly reflecting a decrease of radiocesium concentration in its source materials. Smaller particles had higher radiocesium concentrations, reflecting larger specific surface areas. Silt- and sand-size fractions occupied more than 95 % of the total 137 Cs in the suspended sediments. The contribution of clay-size fractions, which had the highest 137 Cs concentration, was quite small because of their low frequency. A line of the data showed that the particle size distribution of radiocesium was essential to evaluate the migration and distribution of radiocesium in river systems where radiocesium is mainly present as particulate form after the FDNPP accident. (author)

  1. Hydromagnetic thermosolutal instability of compressible walters' (model B' rotating fluid permeated with suspended particles in porous medium

    Directory of Open Access Journals (Sweden)

    G Rana

    2016-09-01

    Full Text Available The thermosolutal instability of compressible Walters' (model B' elastico-viscous rotating fluid permeated with suspended particles (fine dust in the presence of vertical magnetic field in porous medium is considered. By applying normal mode analysis method, the dispersion relation has been derived and solved analytically. It is observed that the rotation, magnetic field, suspended particles and viscoelasticity introduce oscillatory modes. For stationary convection the Walters' (model B' fluid behaves like an ordinary Newtonian fluid and it is observed that the rotation and stable solute gradient has stabilizing effects and suspended particles are found to have destabilizing effect on the system, whereas the medium permeability has stabilizing or destabilizing effect on the system under certain conditions. The magnetic field has destabilizing effect in the absence of rotation, whereas in the presence of rotation, magnetic field has stabilizing or destabilizing effect under certain conditions.

  2. The oceanographic toolbox for the collection of sinking and suspended marine particles

    Science.gov (United States)

    McDonnell, Andrew M. P.; Lam, Phoebe J.; Lamborg, Carl H.; Buesseler, Ken O.; Sanders, Richard; Riley, Jennifer S.; Marsay, Chris; Smith, Helen E. K.; Sargent, Elizabeth C.; Lampitt, Richard S.; Bishop, James K. B.

    2015-04-01

    Marine particles play a central role in controlling the transport, cycling, and inventories of many major elements and trace elements and isotopes throughout the oceans. Studies seeking to elucidate the biogeochemical roles of marine particles often require reliable ways to collect them from the ocean. Here, we review the oceanographic toolbox of techniques and instrumentation that are employed to collect both suspended and sinking particles. With these tools, it is possible to determine both the concentrations and vertical fluxes of important elements and individual particle types. We describe the various methods for quantifying the concentrations of particulate matter with in situ pumps, towed sampling devices, bottle collectors, and large volume capture devices. The uses of various types of flux collection platforms are discussed including surface tethered, neutrally buoyant, and bottom moored devices. We address the issues of sediment trap collection biases and the apparent inconsistencies that can arise due to differences in the temporal and spatial scales sampled by the various methodologies. Special attention is given to collection considerations made for the analysis of trace metals and isotopes, as these methodologies are of high importance to the ongoing GEOTRACES program which seeks to identify the processes and quantify fluxes that control the distributions of key trace elements and isotopes in the ocean. With the emergence of new particle collection methodologies and the continued reliance on traditional collection methods, it is imperative that we combine these multiple approaches in ways that will help improve their accuracy and precision while enhancing their utility in advancing understanding of the biogeochemical and ecological roles of marine particles.

  3. Sampling in freshwater environments: Suspended particle traps and variability in the final data

    International Nuclear Information System (INIS)

    Barbizzi, Sabrina; Pati, Alessandra

    2008-01-01

    This paper reports one practical method to estimate the measurement uncertainty including sampling, derived by the approach implemented by Ramsey for soil investigations. The methodology has been applied to estimate the measurements uncertainty (sampling and analyses) of 137 Cs activity concentration (Bq kg -1 ) and total carbon content (%) in suspended particle sampling in a freshwater ecosystem. Uncertainty estimates for between locations, sampling and analysis components have been evaluated. For the considered measurands, the relative expanded measurement uncertainties are 12.3% for 137 Cs and 4.5% for total carbon. For 137 Cs, the measurement (sampling+analysis) variance gives the major contribution to the total variance, while for total carbon the spatial variance is the dominant contributor to the total variance. The limitations and advantages of this basic method are discussed

  4. Field measurements of bottom boundary layer and suspend particle materials on Jyoban coast in Japan

    International Nuclear Information System (INIS)

    Yagi, Hiroshi; Sugimatsu, Kouichi; Nishi, Yoshihiro; Kawamata, Shigeru; Nakayama, Akiyoshi; Udagawa, Toru; Suzuki, Akira

    2013-01-01

    To understand the characteristics of the bottom boundary layer (BBL), movements of suspended particle material (SPM) and its related radionuclide transport on Jyoban coast, the continuous monitoring of bottom environments using the mooring system and the intensive field survey of BBL with FRA-TRIPOD were performed. The observation results have shown the fundamental characteristics of BBL (vertical distributions of velocities and bottom roughness, etc.) and bottom turbidity variations. The turbidity at the shallow water depth (30 m) was strongly influenced by waves and turbid water generated on rough wave conditions was transported by the coastal currents with the several days period. Turbidities at the deeper depths (80 m and 130 m) were affected by semidiurnal internal tides. (author)

  5. Sampling in freshwater environments: suspended particle traps and variability in the final data.

    Science.gov (United States)

    Barbizzi, Sabrina; Pati, Alessandra

    2008-11-01

    This paper reports one practical method to estimate the measurement uncertainty including sampling, derived by the approach implemented by Ramsey for soil investigations. The methodology has been applied to estimate the measurements uncertainty (sampling and analyses) of (137)Cs activity concentration (Bq kg(-1)) and total carbon content (%) in suspended particle sampling in a freshwater ecosystem. Uncertainty estimates for between locations, sampling and analysis components have been evaluated. For the considered measurands, the relative expanded measurement uncertainties are 12.3% for (137)Cs and 4.5% for total carbon. For (137)Cs, the measurement (sampling+analysis) variance gives the major contribution to the total variance, while for total carbon the spatial variance is the dominant contributor to the total variance. The limitations and advantages of this basic method are discussed.

  6. A mathematical theorem on the onset of Couple-Stress fluid permeated with suspended dust particles saturating a porous medium

    Directory of Open Access Journals (Sweden)

    G Rana

    2016-09-01

    Full Text Available In this paper, the effect of suspended particles on thermal convection in Couple-Stress fluid saturating a porous medium is considered. By applying linear stability theory and normal mode analysis method, a mathematical theorem is derived which states that the viscoelastic thermal convection at marginal state, cannot manifest as stationary convection if the thermal Rayleigh number R, the medium permeability parameter Pl, the couple-stress parameter F and suspended particles parameter B, satisfy the inequality

  7. Application of nuclear techniques to the measurement of rock density and transport of solid particles suspended in rivers

    International Nuclear Information System (INIS)

    Seddiki, A.

    1984-10-01

    In order to better understand hydron phenomens in semi-arid regions characterized by torrential rains, we measured solid particles suspended to dums and in rivers. We also determined the density profile of a drilling and density of saline solutions. We designed an automatic nuclear gauge used for measuring the concentration of particles suspended to rivers. The installation, calibration and operations of a LABEN gauge were done in BENI SLIMANE on the 27th and 28th of February, 1984. The first results we obtained were received on the 24th of April, 1984

  8. Insights into particle cycling in the Sargasso Sea from lipid biomarkers in suspended particles: Seasonality and physical forcing

    Science.gov (United States)

    Pedrosa Pàmies, R.; Conte, M. H.; Weber, J.

    2017-12-01

    Lipid biomarkers elucidate organic material (OM) sources and cycling within the water column. Biomarker composition and bulk properties (organic carbon (OC), nitrogen (N), OC/N ratio, CaCO3 and stable isotopes) were determined in suspended particles (30-4400 m, 100 mab) collected at Oceanic Flux Program site offshore Bermuda in April/November 2015 and October 2016, three periods of contrasting oceanographic conditions. Key lipid biomarkers were used to evaluate the relative importance of phytoplankton-, bacterial- and zooplankton-OM sources, diagenetic reprocessing, and the impact of upper ocean environmental forcing on the carbon pump. Additionally, we assessed benthic remineralization by comparing particles above and within the nepheloid layer (4400 m). N-fatty acids, n-alcohols and sterols comprise up to 85%, 12% and 7%, respectively, of total extractable lipids. Higher lipid concentrations in April vs November 2015 mirror seasonality in primary production, while change in sterol composition reflect shifts in phytoplankton community structure. In the mesopelagic zone, increased cholesterol/phytosterol ratios and percentages of C16 and C18 n-alcohols, odd-chain and branched n-fatty acids document a transition from algal to animal OM sources as well as bacterial reprocessing of labile OM. The impact of Hurricane Nicole (October 2016) on the mixed layer and subsequent increases in production/flux was evident in higher concentrations as well as greater depth penetration of particulate N and fresh/labile algal biomarkers (e.g. 18:5 ω3 and 22:6 ω3 polyunsaturated fatty acids) in the upper 1000 m. Suspended particles in the nepheloid layer had higher concentrations of OC and N and were more depleted in d13C than particles at 4200 m for all dates. While nepheloid lipid composition was similar for all dates, lipid concentrations in April 2015 (seasonal production peak) and October 2016 (hurricane physical forcing) were higher than in November 2015, consistent with the

  9. Characterization of the Particle Size Fraction associated with Heavy Metals in Suspended Sediments of the Yellow River

    Directory of Open Access Journals (Sweden)

    Qingzhen Yao

    2015-06-01

    Full Text Available Variations in the concentrations of particulate heavy metals and fluxes into the sea in the Yellow River were examined based on observational and measured data from January 2009 to December 2010. A custom-built water elutriation apparatus was used to separate suspended sediments into five size fractions. Clay and very fine silt is the dominant fraction in most of the suspended sediments, accounting for >40% of the samples. Cu, Pb, Zn, Cr, Fe and Mn are slightly affected by anthropogenic activities, while Cd is moderate affected. The concentrations of heavy metals increased with decrease in particle size. For suspended sediments in the Yellow River, on average 78%–82% of the total heavy metal loading accumulated in the <16 μm fraction. About 43% and 53% of heavy metal in 2009 and 2010 respectively, were readily transported to the Bohai Sea with “truly suspended” particles, which have potentially harmful effects on marine organisms.

  10. The acoustic radiation force on a small thermoviscous or thermoelastic particle suspended in a viscous and heat-conducting fluid

    Science.gov (United States)

    Karlsen, Jonas; Bruus, Henrik

    2015-11-01

    We present a theoretical analysis (arxiv.org/abs/1507.01043) of the acoustic radiation force on a single small particle, either a thermoviscous fluid droplet or a thermoelastic solid particle, suspended in a viscous and heat-conducting fluid. Our analysis places no restrictions on the viscous and thermal boundary layer thicknesses relative to the particle radius, but it assumes the particle to be small in comparison to the acoustic wavelength. This is the limit relevant to scattering of ultrasound waves from sub-micrometer particles. For particle sizes smaller than the boundary layer widths, our theory leads to profound consequences for the acoustic radiation force. For example, for liquid droplets and solid particles suspended in gasses we predict forces orders of magnitude larger than expected from ideal-fluid theory. Moreover, for certain relevant choices of materials, we find a sign change in the acoustic radiation force on different-sized but otherwise identical particles. These findings lead to the concept of a particle-size-dependent acoustophoretic contrast factor, highly relevant to applications in acoustic levitation or separation of micro-particles in gases, as well as to handling of μm- and nm-sized particles such as bacteria and vira in lab-on-a-chip systems.

  11. Real-time measurements of suspended sediment concentration and particle size using five techniques

    Science.gov (United States)

    Felix, D.; Albayrak, I.; Abgottspon, A.; Boes, R. M.

    2016-11-01

    Fine sediments are important in the design and operation of hydropower plants (HPPs), in particular with respect to sediment management and hydro-abrasive erosion in hydraulic machines. Therefore, there is a need for reliable real-time measurements of suspended sediment mass concentration (SSC) and particle size distribution (PSD). The following instruments for SSC measurements were investigated in a field study during several years at the HPP Fieschertal in the Swiss Alps: (1) turbidimeters, (2) a Laser In-Situ Scattering and Trans- missometry instrument (LISST), (3) a Coriolis Flow and Density Meter (CFDM), (4) acoustic transducers, and (5) pressure sensors. LISST provided PSDs in addition to concentrations. Reference SSCs were obtained by gravimetrical analysis of automatically taken water samples. In contrast to widely used turbidimeters and the single-frequency acoustic method, SSCs obtained from LISST, the CFDM or the pressure sensors were less or not affected by particle size variations. The CFDM and the pressure sensors allowed measuring higher SSC than the optical or the acoustic techniques (without dilution). The CFDM and the pressure sensors were found to be suitable to measure SSC ≥ 2 g/l. In this paper, the measuring techniques, instruments, setup, methods for data treatment, and selected results are presented and discussed.

  12. Seasonal variations of total suspended particles (TSP) and heavy metals under tropical conditions in Rio de Janeiro, Brazil

    International Nuclear Information System (INIS)

    Pfeiffer, W.C.; Trindade, H.A.; Costa-Ribeiro, C.; Londres, H.; Oliveira, A.E.

    The total suspended particle (TSP) and heavy metal concentrations are studied in Rio de Janeiro, Brazil from 1974 until 1981. The principal aims are to determine how these things vary in two different areas and how meteorological parameters responsible for the transport and dilution of atmospheric pollutants affect these areas. (M.A.C.) [pt

  13. Properties and effects of dust particles suspended in the martian atmosphere

    International Nuclear Information System (INIS)

    Pollack, J.B.; Colburn, D.S.; Flasar, M.; Kahn, R.; Carlston, C.E.; Pidek, D.

    1979-01-01

    Direct measurements of the optical depth above the two Viking landers are reported for a period of covering the summer, fall, and winter seasons in the northern hemisphere, a time period during which two global dust storms occurred. The optical depth had a value of about 1 just before the onset of each storm; it increased very rapidly, on a time scale of a few days, to peak values of about 3 and 6 with the arrival of the first and second storms, respectively; and its steadily decreased shortly thereafter (> or approx. = few days to few weeks) for both storms, with the decay occurring more rapidly during the initial period of decay. We have also carried out further analyses of observations of the sky brightness made with the lander cameras during the summer season to obtain improved estimates of other dust particle parameters, including the cross section weighted mean particle radius, several shape factors, and the imaginary indices of refraction. These results have been used to define the radiative properties of the suspended dust particles at solar wavelenths. The derived radiative properties of the dust were incorporated into a 1D radiative convective model. Satisfactory agreement with the temperature structure determined during the descent of the landers to the surface. Is achieved when allowance is made for the effects of vertical motions induced by large scale atmospheric dynamics. The diurnal temperature variations predicted by the 1D calculations for the observed optical depths are also in crude agreement with values inferred from orbiter and lander measurements. The 1D model predicts that the diurnal temperature change and daily mean temperature, averaged over the entire atmospheric vertical column, steadily increase as the optical depth of the dust increases to a value of several, and then subsequently change little

  14. Inert tracer wind resuspension as a function of wind speed, atmospheric stability, and initial tracer particle size

    International Nuclear Information System (INIS)

    Sehmel, G.A.; Lloyd, F.D.

    1979-01-01

    Wind-caused resuspension rates are being determined in three different, long-term, inert-tracer field experiments. Chemical results were recently received from an accumulated backlog of air filter samples. Resuspension rates are yet to be calculated from these data

  15. Suspended particles only marginally reduce pyrethroid toxicity to the freshwater invertebrate Gammarus pulex (L.) during pulse exposure.

    Science.gov (United States)

    Rasmussen, Jes Jessen; Cedergreen, Nina; Kronvang, Brian; Andersen, Maj-Britt Bjergager; Nørum, Ulrik; Kretschmann, Andreas; Strobel, Bjarne Westergaard; Hansen, Hans Christian Bruun

    2016-04-01

    Current ecotoxicological research on particle-associated pyrethroids in freshwater systems focuses almost exclusively on sediment-exposure scenarios and sediment-dwelling macroinvertebrates. We studied how suspended particles influence acute effects of lambda-cyhalothrin and bifenthrin on the epibenthic freshwater amphipod Gammarus pulex (L.) using brief pulse exposures followed by a 144 h post exposure recovery phase. Humic acid (HA) and the clay mineral montmorillonite (MM) were used as model sorbents in environmentally realistic concentrations (5, 25 and 125 mg L(-1)). Mortality of G. pulex was recorded during the post exposure recovery phase and locomotor behavior was measured during exposure to lambda-cyhalothrin. We found that HA in concentrations ≥25 mg L(-1) adsorbed the majority of pyrethroids but only reduced mortality of G. pulex up to a factor of four compared to pyrethroid-only treatments. MM suspensions adsorbed a variable fraction of pyrethroids (10% for bifenthrin and 70% for lambda-cyhalothrin) but did not significantly change the concentration-response relationship compared to pure pyrethroid treatments. Behavioral responses and immobilisation rate of G. pulex were reduced in the presence of HA, whereas behavioral responses and immobilisation rate were increased in the presence of MM. This indicates that G. pulex was capable of sensing the bioavailable fraction of lambda-cyhalothrin. Our results imply that suspended particles reduce to only a limited extent the toxicity of pyrethroids to G. pulex and that passive uptake of pyrethroids can be significant even when pyrethroids are adsorbed to suspended particles.

  16. Characterisation of a re-cast composite Nafion® 1100 series of proton exchange membranes incorporating inert inorganic oxide particles

    OpenAIRE

    Slade, S.; Smith, James; Campbell, S.; Ralph, T.; Ponce de Leon, C.; Walsh, F.

    2010-01-01

    A series of cation exchange membranes was produced by impregnating and coating both sides of a quartz web with a Nafion® solution (1100 EW, 10%wt in water). Inert filler particles (SiO2, ZrO2 or TiO2; 5–20%wt) were incorporated into the aqueous Nafion® solution to produce robust, composite membranes. Ion-exchange capacity/equivalent weight, water take-up, thickness change on hydration and ionic and electrical conductivity were measured in 1 mol dm−3 sulfuric acid at 298 K. The TiO2 filler sig...

  17. Emanation of /sup 232/U daughter products from submicrometer particles of uranium oxide and thorium dioxide by nuclear recoil and inert gas diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Coombs, M.A.; Cuddihy, R.G. (Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (USA). Inhalation Toxicology Research Inst.)

    1983-01-01

    Emanation of /sup 232/U daughter products by nuclear recoil and inert gas diffusion from spherical, submicrometer particles of uranium oxide and thorium dioxide was studied. Monodisperse samples of particles containing 1% /sup 232/U and having physical diameters between 0.1 and 1 ..mu..m were used for the emanation measurements. Thorium-228 ions recoiling from the particles after alpha-decay of /sup 232/U were collected electrostatically on a recoil cathode. Radon-220 diffusing from the particles was swept by an airstream into a 4 l. chamber where the /sup 220/Rn daughters were collected on a second cathode. Mathematical models of radionuclide emanation from spherical particles were used to calculate the recoil range of /sup 228/Th and the diffusion coefficient of /sup 220/Rn in the particle matrix. A /sup 228/Th recoil range of 0.02 ..mu..m and a /sup 220/Rn diffusion coefficient of 3 x 10/sup -14/ cm/sup 2//sec were obtained in both uranium oxide and thorium dioxide particles.

  18. The role of colloids and suspended particles in radionuclide transport in the Canadian concept for nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Vilks, P.

    1994-02-01

    AECL Research is developing a concept for the permanent disposal of nuclear fuel waste in a deep engineered vault in plutonic rock of the Canadian Shield and is preparing an Environmental Impact Statement (EIS) to document its case for the acceptability of the disposal concept. This report, one in a series of supporting documents for the EIS, addresses the role of particles in radionuclide transport. It summarizes our studies of natural particles in groundwater and presents the arguments used to justify the omission of particle-facilitated transport in the geosphere model that is based on the Whiteshell Research Area (WRA) and used in the postclosure assessment study case. Because radiocolloids formed in the vault will not be able to migrate through the clay buffer, radiocolloid formation in the geosphere will be determined by the sorption of radionuclides onto particles in groundwater. These particles consist of typical fracture-lining minerals, such as clays, micas and quartz; precipitated particles, such as colloidal silica and Fe-Si oxyhydroxides; and organic particles. In groundwater from the WRA, the average concentrations of colloids and suspended particles are 0.34 and 1.4 mg/L respectively. Particle-facilitated transport is not included in the geosphere model because the concentrations of particles in groundwater from the WRA are too low to have a significant impact on radionuclide transport. (author). 92 refs., 11 tabs., 13 figs

  19. Arsenic speciation in water, suspended particles, and coastal organisms from the Taehwa River Estuary of South Korea

    International Nuclear Information System (INIS)

    Hong, Seongjin; Kwon, Hye-Ok; Choi, Sung-Deuk; Lee, Jung-Suk; Khim, Jong Seong

    2016-01-01

    Water, suspended particulate matter (SPM), and biota samples were collected from the Taehwa River Estuary to determine the distributions, partitioning, and bioaccumulation of arsenicals. Six forms of As were quantitated by the use of HPLC-ICP/MS. As was found mainly near urban and industrial areas, and inorganic As V was the predominant As form in both water and SPM. Particulate arsenicals were found at the greatest concentrations in coarse particles (> 180 μm), followed by medium (30–180 μm) and fine (0.45–30 μm) particles, in freshwater. Arsenical concentrations were similar across the three particle fractions in saltwater. Field-based distribution coefficient (K d ) values for As depended strongly on SPM, with a less robust dependence on salinity. Concentrations of As were greater in macroalgae than in marine animals, such as fishes, bivalves, crabs, shrimps, and gastropods. Overall, the results of the present study provide useful information on the behaviors and fate of arsenicals in an estuarine environment. - Highlights: •Concentrations of As were greater in industrial and urban areas than in suburban area. •The predominant form of As in water and suspended particles was inorganic As V . •Particle-size distributions of arsenicals differed between freshwater and saltwater. •The K d values for As depended strongly on the presence of SPMs along the estuary. •Greater concentrations of arsenicals were found in macroalgae than in marine animals.

  20. Influence of microorganism content in suspended particles on the particle-water partitioning of mercury in semi-enclosed coastal waters.

    Science.gov (United States)

    Jang, Jiyi; Kim, Hyunji; Han, Seunghee

    2014-02-01

    It is known that particle scavenging of mercury (Hg) can be affected by the abundance of particulate organic matter in coastal waters. However, the role of living organic particles in Hg scavenging is not yet completely understood. In this study, we hypothesized that an abundance of living organic particles (i.e., phytoplankton and bacteria) would influence the particle-water partitioning of Hg in coastal waters. Surface seawater samples were collected from eight stations in Gwangyang Bay, Korea, in three seasons (November 2009, April 2010, and October 2010) for the determination of concentrations of suspended particulate matter (including chlorophyll-a and bacteria), and Hg in unfiltered and filtered waters. We found that more Hg partitioned toward particulate matter when phytoplankton biomass, indicated from the chlorophyll-a concentration in a particle, was higher. In the low algal season, when [chlorophyll-a]algae to transfer Hg to marine food chains. © 2013.

  1. Numerical simulation of microstructure formation of suspended particles in magnetorheological fluids

    International Nuclear Information System (INIS)

    Ido, Y; Inagaki, T; Yamaguchi, T

    2010-01-01

    Microstructure formation of magnetic particles and nonmagnetic particles in magnetorheological (MR) fluids is investigated using the particle method simulation based on simplified Stokesian dynamics. Spherical nonmagnetic particles are rearranged in the field direction due to the formation of magnetic particles in chain-like clusters. Cluster formation of spherocylindrical magnetic particles forces spherical nonmagnetic particles to arrange in the direction of the field. In contrast, the spherocylindrical nonmagnetic particles, with an aspect ratio of two or three, are not sufficiently rearranged in the field direction by cluster formation of spherical magnetic particles. Even after cluster formation in the presence of a magnetic field, the uniformity of distribution of particles on the plane perpendicular to the field direction shows very little change. However, the deviation of uniformity in particle distribution is reduced when the volume fraction of magnetic particles is the same as that of nonmagnetic particles.

  2. Individual particle analysis of coarse air suspended particulate material by synchrotron radiation X-ray micro fluorescence

    International Nuclear Information System (INIS)

    Moreira, Silvana; Melo Junior, Ariston; Vives, Ana Elisa S. de; Nascimento Filho, Virgilio F.

    2005-01-01

    The purpose of this work is evaluate the size of individual particles present in the air suspended particulate material collected in Campinas, Sao Paulo State, and analyze quantitatively the particles using the synchrotron radiation X-ray micro fluorescence (μ-SRXRF) associated with the fundamental parameter method to correct attenuation/absorption effects by the matrix. The particles analyzed have size between 50-10 μm and to perform the spatial distribution a white beam of synchrotron radiation condensed by a conical capillary (13 μm diameter) was used. For the quantitative analysis punctual measures in thin films standards in Mylar subtract were performed. The elements detected were Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ba and Pb. (author)

  3. Individual particle analysis of coarse air suspended particulate material by synchrotron radiation X-ray micro fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Silvana; Melo Junior, Ariston [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo. Dept. de Recursos Hidricos]. E-mail: silvana@fec.unicamp.br; Perez, Carlos Alberto [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil)]. E-mail: perez@lnls.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Nascimento Filho, Virgilio F. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear]. E-mail: virgilio@cena.usp.br

    2005-07-01

    The purpose of this work is evaluate the size of individual particles present in the air suspended particulate material collected in Campinas, Sao Paulo State, and analyze quantitatively the particles using the synchrotron radiation X-ray micro fluorescence ({mu}-SRXRF) associated with the fundamental parameter method to correct attenuation/absorption effects by the matrix. The particles analyzed have size between 50-10 {mu}m and to perform the spatial distribution a white beam of synchrotron radiation condensed by a conical capillary (13 {mu}m diameter) was used. For the quantitative analysis punctual measures in thin films standards in Mylar subtract were performed. The elements detected were Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ba and Pb. (author)

  4. Fast numerical method for solving the three-dimensional Stokes' equations in the presence of suspended particles

    International Nuclear Information System (INIS)

    Fogelson, A.L.; Peskin, C.S.

    1988-01-01

    A new fast numerical method for solving the three-dimensional Stokes' equations in the presence of suspended particles is presented. The fluid dynamics equations are solved on a lattice. A particle is represented by a set of points each of which moves at the local fluid velocity and is not constrained to lie on the lattice. These points are coupled by forces which resist deformation of the particle. These forces contribute to the force density in the Stokes' equations. As a result, a single set of fluid dynamics equations holds at all points of the domain and there are no internal boundaries. Particles size, shape, and deformability may be prescribed. Computational work increases only linearly with the number of particles, so large numbers (500--1000) of particles may be studied efficiently. The numerical method involves implicit calculation of the particle forces by minimizing an energy function and solution of a finite-difference approximation to the Stokes' equations using the Fourier--Toeplitz method. The numerical method has been implemented to run on all CRAY computers: the implementation exploits the CRAY's vectorized arithmetic, and on machines with insufficient central memory, it performs efficient disk I/O while storing most of the data on disk. Applications of the method to sedimentation of one-, two-, and many-particle systems are described. Trajectories and settling speeds for two-particle sedimentation, and settling speed for multiparticle sedimentation from initial distributions on a cubic lattice or at random give good quantitative agreement with existing theories. copyright 1988 Academic Press, Inc

  5. Suspended organic particles drive the development of attached algal communities in degraded peatlands

    NARCIS (Netherlands)

    Goldenberg Vilar, Alejandra; Vonk, J. Arie; van der geest, Harm; van Dam, Herman; Bichebois, Simon; Admiraal, Wim

    2014-01-01

    Mineral particles in rivers have been shown to cover adnate algal species, promoting motile and filamentous species. Such effects and the role of detrital particles have not been studied in stagnant waters. In degraded peat lands, detrital particles are very prominent and therefore we studied the

  6. Detectable elements in a particles pattern of suspended urban matter analysed by neutron activation

    International Nuclear Information System (INIS)

    Herrera, L.; Beltran, C.; Alemon, E.; Ortiz, M.E.

    2001-01-01

    The multielement composition of a Standard Reference Material 1648 pattern certified is reported and it is used for the suspended in air aerosol samples analysis from urban localities of the Valley of Mexico, which was irradiated in the same geometry of the sample. The bottom of laboratory is analysed where was made the gamma spectrometry and it is compared the ratio of country up of bottom photo peaks with pattern photo peaks in nearer interest regions. The bottom natural gamma transmitters were identified and those of the activated pattern in the TRIGA Mark III nuclear reactor. (Author)

  7. Evaluating unsupervised methods to size and classify suspended particles using digital in-line holography

    Science.gov (United States)

    Davies, Emlyn J.; Buscombe, Daniel D.; Graham, George W.; Nimmo-Smith, W. Alex M.

    2015-01-01

    Substantial information can be gained from digital in-line holography of marine particles, eliminating depth-of-field and focusing errors associated with standard lens-based imaging methods. However, for the technique to reach its full potential in oceanographic research, fully unsupervised (automated) methods are required for focusing, segmentation, sizing and classification of particles. These computational challenges are the subject of this paper, in which we draw upon data collected using a variety of holographic systems developed at Plymouth University, UK, from a significant range of particle types, sizes and shapes. A new method for noise reduction in reconstructed planes is found to be successful in aiding particle segmentation and sizing. The performance of an automated routine for deriving particle characteristics (and subsequent size distributions) is evaluated against equivalent size metrics obtained by a trained operative measuring grain axes on screen. The unsupervised method is found to be reliable, despite some errors resulting from over-segmentation of particles. A simple unsupervised particle classification system is developed, and is capable of successfully differentiating sand grains, bubbles and diatoms from within the surf-zone. Avoiding miscounting bubbles and biological particles as sand grains enables more accurate estimates of sand concentrations, and is especially important in deployments of particle monitoring instrumentation in aerated water. Perhaps the greatest potential for further development in the computational aspects of particle holography is in the area of unsupervised particle classification. The simple method proposed here provides a foundation upon which further development could lead to reliable identification of more complex particle populations, such as those containing phytoplankton, zooplankton, flocculated cohesive sediments and oil droplets.

  8. Temperature effects on drift of suspended single-domain particles induced by the Magnus force

    Science.gov (United States)

    Denisov, S. I.; Lyutyy, T. V.; Reva, V. V.; Yermolenko, A. S.

    2018-03-01

    We study the temperature dependence of the drift velocity of single-domain ferromagnetic particles induced by the Magnus force in a dilute suspension. A set of stochastic equations describing the translational and rotational dynamics of particles is derived, and the particle drift velocity that depends on components of the average particle magnetization is introduced. The Fokker-Planck equation for the probability density of magnetization orientations is solved analytically in the limit of strong thermal fluctuations for both the planar rotor and general models. Using these solutions, we calculate the drift velocity and show that the out-of-plane fluctuations of magnetization, which are not accounted for in the planar rotor model, play an important role. In the general case of arbitrary fluctuations, we investigate the temperature dependence of the drift velocity by numerically simulating a set of effective stochastic differential equations for the magnetization dynamics.

  9. Multiphysics modelling of the separation of suspended particles via frequency ramping of ultrasonic standing waves.

    Science.gov (United States)

    Trujillo, Francisco J; Eberhardt, Sebastian; Möller, Dirk; Dual, Jurg; Knoerzer, Kai

    2013-03-01

    A model was developed to determine the local changes of concentration of particles and the formations of bands induced by a standing acoustic wave field subjected to a sawtooth frequency ramping pattern. The mass transport equation was modified to incorporate the effect of acoustic forces on the concentration of particles. This was achieved by balancing the forces acting on particles. The frequency ramping was implemented as a parametric sweep for the time harmonic frequency response in time steps of 0.1s. The physics phenomena of piezoelectricity, acoustic fields and diffusion of particles were coupled and solved in COMSOL Multiphysics™ (COMSOL AB, Stockholm, Sweden) following a three step approach. The first step solves the governing partial differential equations describing the acoustic field by assuming that the pressure field achieves a pseudo steady state. In the second step, the acoustic radiation force is calculated from the pressure field. The final step allows calculating the locally changing concentration of particles as a function of time by solving the modified equation of particle transport. The diffusivity was calculated as function of concentration following the Garg and Ruthven equation which describes the steep increase of diffusivity when the concentration approaches saturation. However, it was found that this steep increase creates numerical instabilities at high voltages (in the piezoelectricity equations) and high initial particle concentration. The model was simplified to a pseudo one-dimensional case due to computation power limitations. The predicted particle distribution calculated with the model is in good agreement with the experimental data as it follows accurately the movement of the bands in the centre of the chamber. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  10. Measurements of Plutonium and Americium in Soil Samples from Project 57 using the Suspended Soil Particle Sizing System (SSPSS)

    International Nuclear Information System (INIS)

    John L. Bowen; Rowena Gonzalez; David S. Shafer

    2001-01-01

    As part of the preliminary site characterization conducted for Project 57, soils samples were collected for separation into several size-fractions using the Suspended Soil Particle Sizing System (SSPSS). Soil samples were collected specifically for separation by the SSPSS at three general locations in the deposited Project 57 plume, the projected radioactivity of which ranged from 100 to 600 pCi/g. The primary purpose in focusing on samples with this level of activity is that it would represent anticipated residual soil contamination levels at the site after corrective actions are completed. Consequently, the results of the SSPSS analysis can contribute to dose calculation and corrective action-level determinations for future land-use scenarios at the site

  11. Suspended-sediment concentrations, loads, total suspended solids, turbidity, and particle-size fractions for selected rivers in Minnesota, 2007 through 2011

    Science.gov (United States)

    Ellison, Christopher A.; Savage, Brett E.; Johnson, Gregory D.

    2014-01-01

    Sediment-laden rivers and streams pose substantial environmental and economic challenges. Excessive sediment transport in rivers causes problems for flood control, soil conservation, irrigation, aquatic health, and navigation, and transports harmful contaminants like organic chemicals and eutrophication-causing nutrients. In Minnesota, more than 5,800 miles of streams are identified as impaired by the Minnesota Pollution Control Agency (MPCA) due to elevated levels of suspended sediment. The U.S. Geological Survey, in cooperation with the MPCA, established a sediment monitoring network in 2007 and began systematic sampling of suspended-sediment concentrations (SSC), total suspended solids (TSS), and turbidity in rivers across Minnesota to improve the understanding of fluvial sediment transport relations. Suspended-sediment samples collected from 14 sites from 2007 through 2011 indicated that the Zumbro River at Kellogg in the driftless region of southeast Minnesota had the highest mean SSC of 226 milligrams per liter (mg/L) followed by the Minnesota River at Mankato with a mean SSC of 193 mg/L. During the 2011 spring runoff, the single highest SSC of 1,250 mg/L was measured at the Zumbro River. The lowest mean SSC of 21 mg/L was measured at Rice Creek in the northern Minneapolis- St. Paul metropolitan area. Total suspended solids (TSS) have been used as a measure of fluvial sediment by the MPCA since the early 1970s; however, TSS concentrations have been determined to underrepresent the amount of suspended sediment. Because of this, the MPCA was interested in quantifying the differences between SSC and TSS in different parts of the State. Comparisons between concurrently sampled SSC and TSS indicated significant differences at every site, with SSC on average two times larger than TSS concentrations. The largest percent difference between SSC and TSS was measured at the South Branch Buffalo River at Sabin, and the smallest difference was observed at the Des Moines

  12. Influence of suspended particles on the emission of organophosphate flame retardant from insulation boards.

    Science.gov (United States)

    Lazarov, Borislav; Swinnen, Rudi; Poelmans, David; Spruyt, Maarten; Goelen, Eddy; Covaci, Adrian; Stranger, Marianne

    2016-09-01

    The influence of the presence of the so-called seed particles on the emission rate of Tris (1-chloroisopropyl) phosphate (TCIPP) from polyisocyanurate (PIR) insulation boards was investigated in this study. Two Field and Laboratory Emission Test cells (FLEC) were placed on the surface of the same PIR board and respectively supplied with clean air (reference FLEC) and air containing laboratory-generated soot particles (test FLEC). The behavior of the area-specific emission rates (SER A ) over a time period of 10 days was studied by measuring the total (gas + particles) concentrations of TCIPP at the exhaust of each FLEC. The estimated SER A of TCIPP from the PIR board at the quasi-static equilibrium were found to be 0.82 μg m(-2) h(-1) in the absence of seed particles, while the addition of soot particles led to SER A of 2.16 μg m(-2) h(-1). This indicates an increase of the SER A of TCIPP from the PIR board with a factor of 3 in the presence of soot particles. The TCIPP partition coefficient to soot particles at the quasi-static equilibrium was 0.022 ± 0.012 m(3) μg(-1). In the next step, the influence of real-life particles on TCIPP emission rates was investigated by supplying the test FLEC with air from a professional kitchen where mainly frying and baking activities took place. Similar to the reference FLEC outcomes, SER A was also found to increase in this real-life experiment over a time period of 20 days by a factor 3 in the presence of particles generated during cooking activities. The median value of estimated particle-gas coefficient for this test was 0.062 ± 0.037 m(3) μg(-1).

  13. Products and kinetics of the heterogeneous reaction of suspended vinclozolin particles with ozone.

    Science.gov (United States)

    Gan, Jie; Yang, Bo; Zhang, Yang; Shu, Xi; Liu, Changgeng; Shu, Jinian

    2010-11-25

    Vinclozolin is a widely used fungicide that can be released into the atmosphere via application and volatilization. This paper reports an experimental investigation on the heterogeneous ozonation of vinclozolin particles. The ozonation of vinclozolin adsorbed on azelaic acid particles under pseudo-first-order conditions is investigated online with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS). The ozonation products are analyzed with a combination of VUV-ATOFMS and GC/MS. Two main ozonation products are observed. The formation of the ozonation products results from addition of O(3) on the C-C double bond of the vinyl group. The heterogeneous reactive rate constant of vinclozolin particles under room temperature is (2.4 ± 0.4) × 10(-17) cm(3) molecules(-1) s(-1), with a corresponding lifetime at 100 ppbv O(3) of 4.3 ± 0.7 h, which is almost comparable with the estimated lifetime due to the reaction with atmospheric OH radicals (∼1.7 h). The reactive uptake coefficient for O(3) on vinclozolin particles is (6.1 ± 1.0) × 10(-4).

  14. Particle Tracking Model for Suspended Sediment Transport and Streambed Clogging Under Losing and Gaining Conditions

    Science.gov (United States)

    Preziosi-Ribero, A.; Fox, A.; Packman, A. I.; Escobar-Vargas, J.; Donado-Garzon, L. D.; Li, A.; Arnon, S.

    2017-12-01

    Exchange of mass, momentum and energy between surface water and groundwater is a driving factor for the biology, ecology and chemistry of rivers and water bodies in general. Nonetheless, this exchange is dominated by different factors like topography, bed morphology, and large-scale hydraulic gradient. In the particular case of fine sediments like clay, conservative tracer modeling is impossible because they are trapped in river beds for long periods, thus the normal advection dispersion approach leads to errors and results do not agree with reality. This study proposes a numerical particle tracking model that represents the behavior of kaolinite in a sand flume, and how its deposition varies according to different flow conditions, namely losing and gaining flow. Since fine particles do not behave like solutes, kaolinite dynamics are represented using settling velocity and a filtration coefficient allowing the particles to be trapped in the bed. This approach allows us to use measurable parameters directly related with the fine particle features as size and shape, and hydraulic parameters. Results are then compared with experimental results from lab experiments obtained in a recirculating flume, in order to assess the impact of losing and gaining conditions on sediment transport and deposition. Furthermore, our model is able to identify the zones where kaolinite deposition concentrates over the flume due to the bed geometry, and later relate these results with clogging of the bed and hence changes in the bed's hydraulic conductivity. Our results suggest that kaolinite deposition is higher under losing conditions since the vertical velocity of the flow is added to the deposition velocity of the particles modeled. Moreover, the zones where kaolinite concentrates varies under different flow conditions due to the difference in pressure and velocity in the river bed.

  15. Revisiting the use of the immersed-boundary lattice-Boltzmann method for simulations of suspended particles

    Science.gov (United States)

    Mountrakis, L.; Lorenz, E.; Hoekstra, A. G.

    2017-07-01

    no consistent measure to recalibrate the radius of the suspended particle.

  16. Suspended particles only marginally reduce pyrethroid toxicity to the freshwater invertebrate Gammarus pulex (L.) during pulse exposure

    DEFF Research Database (Denmark)

    Rasmussen, Jes; Cedergreen, Nina; Kronvang, Brian

    2016-01-01

    Current ecotoxicological research on particle associated pyrethroids in freshwater systems focuses almost exclusively on sediment-exposure scenarios and sediment-dwelling macroinvertebrates. We studied how suspended particles influence acute effects of lambda-cyhalothrin and bifenthrin on the epi......Current ecotoxicological research on particle associated pyrethroids in freshwater systems focuses almost exclusively on sediment-exposure scenarios and sediment-dwelling macroinvertebrates. We studied how suspended particles influence acute effects of lambda-cyhalothrin and bifenthrin....... MM suspensions adsorbed a variable fraction of pyrethroids (10% for bifenthrin and 70% for lambda-cyhalothrin) but did not significantly change the concentration–response relationship compared to pure pyrethroid treatments. Behavioral responses and immobilisation rate of G. pulex were reduced...

  17. Particle-size dependence of immersion freezing: Investigation of INUIT test aerosol particles with freely suspended water drops.

    Science.gov (United States)

    Diehl, Karoline; Debertshäuser, Michael; Eppers, Oliver; Jantsch, Evelyn; Mitra, Subir K.

    2014-05-01

    One goal of the research group INUIT (Ice Nuclei research UnIT) is to investigate the efficiencies of several test ice nuclei under comparable conditions but with different experimental techniques. In the present studies, two methods are used: the Mainz vertical wind tunnel and an acoustic levitator placed inside a cold chamber. In both cases drops are freely levitated, either at their terminal velocity in the wind tunnel updraft or around the nodes of a standing ultrasonic wave in the acoustic levitator. Thus, heat transfer conditions are well approximated, and wall contact effects on freezing as well as electrical charges of the drops are avoided. Drop radii are 370 μm and 1 mm, respectively. In the wind tunnel, drops are investigated at constant temperatures within a certain time period and the onset of freezing is observed directly. In the acoustic levitator, the drop temperature decreases during the experiments and is measured by an in-situ calibrated Infrared thermometer. The onset of freezing is indicated by a rapid rise of the drop surface temperature because of the release of latent heat. Investigated test ice nuclei are Snomax® as a proxy of biological particles and illite NX as well as K-feldspar as represents of mineral dust. The particle concentrations are 1 × 10-12 to 3 × 10-6 g Snomax® per drop and 5 × 10-9 to 5 × 10-5 g mineral dust per drop. Freezing temperatures are between -2 and -18° C in case of Snomax® and between -14 and -26° C in case of mineral dust. The lower the particle masses per drop the lower are the freezing temperatures. For similar particle concentrations in the drops, the median freezing temperatures determined by the two techniques agree well within the measurement errors. With the knowledge of the specific particle surface area of the mineral dusts, the results are interpreted also in terms of particle surface area per drop. Results from the wind tunnel experiments which are performed at constant temperatures indicate

  18. Visible photoluminescence from hydrogenated silicon particles suspended in a silane plasma

    International Nuclear Information System (INIS)

    Courteille, C.; Dorier, J.L.; Dutta, J.; Hollenstein, C.; Howling, A.A.; Stoto, T.

    1994-09-01

    Visible photoluminescence at room temperature has been observed in amorphous hydrogenated silicon particulates during their formation in a silane radio-frequency plasma. Oxygen injection along with mass spectrometry measurements demonstrate that oxygen has no influence on the photoluminescence. The appearance of visible photoluminescence coincides with a particle agglomeration phase as shown by laser light scattering experiments, and electron microscopy shows silicon nanocrystals within these particulates. These observations of visible photoluminescence are consistent with the model of quantum confinement in the silicon nanocrystals. (author) 5 figs., 45 refs

  19. Identifying primary stressors impacting macroinvertebrates in the Salinas River (California, USA): Relative effects of pesticides and suspended particles

    International Nuclear Information System (INIS)

    Anderson, B.S.; Phillips, B.M.; Hunt, J.W.; Connor, V.; Richard, N.; Tjeerdema, R.S.

    2006-01-01

    Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more important acute stressors of macroinvertebrates than suspended sediments in the Salinas River. - Pesticides are the primary stressor impacting macroinvertebrates in sections of the lower Salinas River

  20. Identifying primary stressors impacting macroinvertebrates in the Salinas River (California, USA): Relative effects of pesticides and suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, B.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)]. E-mail: anderson@ucdavis.edu; Phillips, B.M. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Hunt, J.W. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States); Connor, V. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Richard, N. [Division of Water Quality, State Water Resources Control Board, 1001 I. Street, Sacramento, CA 95814 (United States); Tjeerdema, R.S. [Department of Environmental Toxicology, University of California, Davis, CA 95616 (United States)

    2006-06-15

    Laboratory dose-response experiments with organophosphate and pyrethroid pesticides, and dose-response experiments with increasing particle loads were used to determine which of these stressors were likely responsible for the toxicity and macroinvertebrate impacts previously observed in the Salinas River. Experiments were conducted with the amphipod Hyalella azteca, the baetid mayfly Procloeon sp., and the midge Chironomus dilutus (Shobanov, formerly Chironomus tentans). The results indicate the primary stressor impacting H. azteca was pesticides, including chlorpyrifos and permethrin. The mayfly Procloeon sp. was sensitive to chlorpyrifos and permethrin within the range of concentrations of these pesticides measured in the river. Chironomus dilutus were sensitive to chlorpyrifos within the ranges of concentrations measured in the river. None of the species tested were affected by turbidity as high as 1000 NTUs. The current study shows that pesticides are more important acute stressors of macroinvertebrates than suspended sediments in the Salinas River. - Pesticides are the primary stressor impacting macroinvertebrates in sections of the lower Salinas River.

  1. Nature of suspended particles in hydrothermal plume at 3°40'N Carlsberg ridge: A comparison with deep oceanic suspended matter

    Digital Repository Service at National Institute of Oceanography (India)

    Ray, D.; Babu, E.V.S.S.K.; SuryaPrakash, L.

    , 2000: Guidelines for Planning the Sampling of Atmosphere (Sec- ond Revision). 28. Ruzer, L. S. and Harley, N. H., Aerosols Handbook: Measure- ment, Dosimetry, and Health Effects, CRC Press, 2004, 2nd edn, ISBN: 1439855196, 9781439855195, p. 666. 29...-015-4634-z. 39. Brown, J. S., Gordon, T., Price, O. and Asgharian, B., Thoracic and respirable particle definitions for human health risk assess- ment. Particle Fibre Toxicol., 2013, 10, 12; http://www. particleandfibretoxicology.com/content/10/1/12 40...

  2. Statistical modeling of road contribution as emission sources to total suspended particles (TSP) under MCF model downtown Medellin - Antioquia - Colombia, 2004

    International Nuclear Information System (INIS)

    Gomez, Miryam; Saldarriaga, Julio; Correa, Mauricio; Posada, Enrique; Castrillon M, Francisco Javier

    2007-01-01

    Sand fields, constructions, carbon boilers, roads, and biologic sources are air-contaminant-constituent factors in down town Valle de Aburra, among others. the distribution of road contribution data to total suspended particles according to the source receptor model MCF, source correlation modeling, is nearly a gamma distribution. Chi-square goodness of fit is used to model statistically. This test for goodness of fit also allows estimating the parameters of the distribution utilizing maximum likelihood method. As convergence criteria, the estimation maximization algorithm is used. The mean of road contribution data to total suspended particles according to the source receptor model MCF, is straightforward and validates the road contribution factor to the atmospheric pollution of the zone under study

  3. Current-use pesticides in stream water and suspended particles following runoff: exposure, effects, and mitigation requirements.

    Science.gov (United States)

    Bereswill, Renja; Streloke, Martin; Schulz, Ralf

    2013-06-01

    The European Union's directive for sustainable use of pesticides requires implementing risk mitigation measures at streams threatened by pesticide entries. The need for mitigation measures was investigated at 10 stream sites within an intensively used arable region in central Germany by characterizing pesticide exposure following edge-of-field runoff and effects on the aquatic macroinvertebrates. Moreover, the influence of riparian buffer strip width (as a mitigation measure) at the sampling sites was considered. Generally, invertebrate fauna was dominated by pesticide-tolerant species, suggesting a high pesticide exposure at almost all sites. This result is also reflected by the elevated levels of suspended particle contamination in terms of toxic units (logTUMax  > -2), corresponding to one-hundredth of the median lethal concentration (LC50) to Daphnia magna. At two sites that received high aqueous-phase entries of the pyrethroid lambda-cyhalothrin (logTUMax  > -0.6), the abundance and number of sensitive species in terms of the species at risk index decreased during the pesticide application period. In contrast, no acute significant negative effects on macroinvertebrates were observed at sites characterised by low water-phase toxicity (logTUMax  < -3.5). An influence of riparian buffer strip width on pesticide exposure was not observed, supposedly because of the presence of erosion rills and ephemeral ditches. In conclusion, results show that mitigation measures (such as the improvement of currently present riparian buffer strips) are needed in the study area. Copyright © 2013 SETAC.

  4. Circular motion of particles suspended in a Gaussian beam with circular polarization validates the spin part of the internal energy flow

    DEFF Research Database (Denmark)

    Angelsky, O. V.; Bekshaev, A. Ya.; Maksimyak, P. P.

    2012-01-01

    switching to the right (left) circular polarization, the particles performed spinning motion in agreement with the angular momentum imparted by the field, but they were involved in an orbital rotation around the beam axis as well, which in previous works [Y. Zhao et al, Phys. Rev. Lett. 99, 073901 (2007......Non-spherical dielectric microparticles were suspended in a water-filled cell and exposed to a coherent Gaussian light beam with controlled state of polarization. When the beam polarization is linear, the particles were trapped at certain off-axial position within the beam cross section. After...... of inhomogeneously polarized paraxial beams [A. Bekshaev et al, J. Opt. 13, 053001 (2011)]....

  5. Validation of a low field Rheo-NMR instrument and application to shear-induced migration of suspended non-colloidal particles in Couette flow

    Science.gov (United States)

    Colbourne, A. A.; Blythe, T. W.; Barua, R.; Lovett, S.; Mitchell, J.; Sederman, A. J.; Gladden, L. F.

    2018-01-01

    Nuclear magnetic resonance rheology (Rheo-NMR) is a valuable tool for studying the transport of suspended non-colloidal particles, important in many commercial processes. The Rheo-NMR imaging technique directly and quantitatively measures fluid displacement as a function of radial position. However, the high field magnets typically used in these experiments are unsuitable for the industrial environment and significantly hinder the measurement of shear stress. We introduce a low field Rheo-NMR instrument (1 H resonance frequency of 10.7MHz), which is portable and suitable as a process monitoring tool. This system is applied to the measurement of steady-state velocity profiles of a Newtonian carrier fluid suspending neutrally-buoyant non-colloidal particles at a range of concentrations. The large particle size (diameter > 200 μm) in the system studied requires a wide-gap Couette geometry and the local rheology was expected to be controlled by shear-induced particle migration. The low-field results are validated against high field Rheo-NMR measurements of consistent samples at matched shear rates. Additionally, it is demonstrated that existing models for particle migration fail to adequately describe the solid volume fractions measured in these systems, highlighting the need for improvement. The low field implementation of Rheo-NMR is complementary to shear stress rheology, such that the two techniques could be combined in a single instrument.

  6. Documentation of particle-size analyzer time series, and discrete suspended-sediment and bed-sediment sample data collection, Niobrara River near Spencer, Nebraska, October 2014

    Science.gov (United States)

    Schaepe, Nathaniel J.; Coleman, Anthony M.; Zelt, Ronald B.

    2018-04-06

    The U.S. Geological Survey (USGS), in cooperation with the U.S. Army Corps of Engineers, monitored a sediment release by Nebraska Public Power District from Spencer Dam located on the Niobrara River near Spencer, Nebraska, during the fall of 2014. The accumulated sediment behind Spencer Dam ordinarily is released semiannually; however, the spring 2014 release was postponed until the fall. Because of the postponement, the scheduled fall sediment release would consist of a larger volume of sediment. The larger than normal sediment release expected in fall 2014 provided an opportunity for the USGS and U.S. Army Corps of Engineers to improve the understanding of sediment transport during reservoir sediment releases. A primary objective was to collect continuous suspended-sediment data during the first days of the sediment release to document rapid changes in sediment concentrations. For this purpose, the USGS installed a laser-diffraction particle-size analyzer at a site near the outflow of the dam to collect continuous suspended-sediment data. The laser-diffraction particle-size analyzer measured volumetric particle concentration and particle-size distribution from October 1 to 2 (pre-sediment release) and October 5 to 9 (during sediment release). Additionally, the USGS manually collected discrete suspended-sediment and bed-sediment samples before, during, and after the sediment release. Samples were collected at two sites upstream from Spencer Dam and at three bridges downstream from Spencer Dam. The resulting datasets and basic metadata associated with the datasets were published as a data release; this report provides additional documentation about the data collection methods and the quality of the data.

  7. Influence of microorganism content in suspended particles on the particle–water partitioning of mercury in semi-enclosed coastal waters

    International Nuclear Information System (INIS)

    Jang, Jiyi; Kim, Hyunji; Han, Seunghee

    2014-01-01

    It is known that particle scavenging of mercury (Hg) can be affected by the abundance of particulate organic matter in coastal waters. However, the role of living organic particles in Hg scavenging is not yet completely understood. In this study, we hypothesized that an abundance of living organic particles (i.e., phytoplankton and bacteria) would influence the particle–water partitioning of Hg in coastal waters. Surface seawater samples were collected from eight stations in Gwangyang Bay, Korea, in three seasons (November 2009, April 2010, and October 2010) for the determination of concentrations of suspended particulate matter (including chlorophyll-a and bacteria), and Hg in unfiltered and filtered waters. We found that more Hg partitioned toward particulate matter when phytoplankton biomass, indicated from the chlorophyll-a concentration in a particle, was higher. In the low algal season, when [chlorophyll-a] −1 , the bacterial number, instead of chlorophyll-a concentration in particle, showed a positive correlation with the particle–water partition coefficient of Hg. Overall, microbial abundance seems to play a critical role in particle scavenging of Hg in coastal water. Taking this result in light of Hg in pristine coastal zones, we predict that increases in algal biomass amplify the potential for algae to transfer Hg to marine food chains. - Highlights: • Abundance of phytoplankton and bacteria influenced particle–water partitioning of Hg. • More Hg partitioned toward particles when microorganism biomass in particle is large. • Increases of algal biomass may enhance Hg bioaccumulation in coastal ecosystem

  8. Effects of alcohols on gas holdup and volumetric liquid-phase mass transfer coefficient in gel-particle-suspended bubble column

    Energy Technology Data Exchange (ETDEWEB)

    Salvacion, J.; Murayama, M.; Otaguchi, K.; Koide, K. [Tokyo Institute of Technology, Tokyo (Japan)

    1995-08-20

    The effects of alcohols, column dimensions, gas velocity, physical properties of liquids, and gel particles on the gas holdup e{sub G} and the volumetric liquid-phase mass transfer coefficient k{sub L}a in a gel-particle-suspended bubble column under liquid-solid batch operation were studied experimentally. It was shown that addition of at alcohols to water generally increases e{sub G}. However, k{sub L}a values in aqueous solutions of alcohols became larger or smaller than those in water, according to the kind and concentration of the alcohol added to water. It was also shown that the presence of suspended gel-particles in the bubble column reduces values of e{sub G} and k{sub L}a. Based on these observations, empirical equations for e{sub G} in the transition regime in an ethanol solution, for e{sub G} in the heterogeneous now regime applicable to various alcohol solutions and for k{sub L}a in both now regimes were proposed. 18 refs., 12 figs., 3 tabs.

  9. Acute effects of total suspended particles and sulfur dioxides on preterm delivery: a community-based cohort study

    Energy Technology Data Exchange (ETDEWEB)

    Xu, X.P.; Ding, H.; Wang, X.B. [Harvard University, Boston, MA (United States). Dept. of Environmental Health

    1995-11-01

    The acute effects of air pollution on preterm delivery were examined in a prospective cohort in Beijing, China. From early pregnancy until delivery in 1988, we followed all registered pregnant women who lived in four residential areas of Beijing. Information for both mothers and infants was collected. Daily air pollution and meteorological data were obtained independently. The sample for analysis included 25 370 resident women who gave first live births in 1988. Multiple linear regression and logistic regression were used to estimate the effects of air pollution on gestational age and preterm delivery (i.e. {lt} 37 wk), with adjustment for outdoor temperature and humidity, day of the week, season, maternal age, gender of child, and residential area. Very high concentrations of ambient sulfur dioxide (mean = 102 {mu}g/m{sup 3}), (maximum = 630 {mu}g/m{sup 3}) and total suspended particulates (mean = 375 {mu}g/m{sup 3}), (maximum =1 003 {mu}g/m{sup 3}) were observed in these areas. There was a significant dose-dependent association between gestational age and sulfur dioxide and total suspended particulate concentrations. The estimated reduced duration of gestation was 0.075 wk (12.6 h) and 0.042 wk (7.1 h) for each 100 {mu}g/m{sup 3} increase in sulfur dioxide and total suspended particulates 7-d lagged moving average, respectively. We concluded that high levels of total suspended particulates and sulfur dioxide, or of a more complex pollution mixture associated with these pollutants, appear to contribute to excess risk of preterm delivery in this population. Further work needs to be carried out, with more detailed information on personal exposure and effect modifiers.

  10. Evaluating Suspended Particles Concentration of the Inside and Outside Air of the Classroom and Its Influencing Factors in Middle schools and High Schools of Yazd

    Directory of Open Access Journals (Sweden)

    MH Ehrampoosh

    2015-11-01

    Full Text Available Abstract Introduction: Airborne pollution in such public environments as schools has adverse health effects on pupils and teachers who spend a noticeable amount of time in the school. Therefore, this study aimed to measure the suspended particles concentration of indoor and outdoor air of Yazd schools as well as to determine the influencing parameters on the pollution intensity. Methods: This analytical cross-sectional study was conducted in 20 middle-schools and high schools of males and females in winter of 2013. The environmental aerosol monitoring device, (HAZ-DUST EPAM5000 model was used to measure the concentration of PM1, PM2.5 and PM10. The study data were analyzed via applying correlation, simple linear regression and means comparison tests. Moreover, the study results were compared with the standards of World health organization(WHO and Environmental Health Organization(EPA. Results: The mean concentration of PM10, PM2.5 and PM1 in indoor class air was reported higher compared to the outdoor air. The indoor and outdoor air quality of schools in terms of Air Quality Index9 (AQI Calculator indicated an average condition for PM10, and an unhealthy condition for PM2.5 in regard with the vulnerable groups. A significant relationship was detected between indoor and outdoor air concentration particles (P<0.05. The mean indoor per outdoor air particles ratio (I/O was 1.68, 1.31, 1.46 respectively for PM10, PM2.5, PM1. Conclusion: The study findings revealed a significant relationship between indoor and outdoor suspended particle concentration demonstrating the particles penetration into the classrooms. Therefore, utilizing appropriate air conditioner systems are regarded effective in order to mitigate indoor class pollution.  

  11. Alternative inerting agents

    CSIR Research Space (South Africa)

    Du

    1997-08-01

    Full Text Available Final Project Report ALTERNATIVE INERTING AGENTS Author/s: J J L DU PLESSIS Research Agency: OSIR MINING TECHNOLOGY Project No: Date: 3 2 7 2 COL 443 APRIL 1999 N’ ) ( G~6~ I Title: 9 / The results show...

  12. Inert Anode Report

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1999-07-01

    This ASME report provides a broad assessment of open literature and patents that exist in the area of inert anodes and their related cathode systems and cell designs, technologies that are relevant for the advanced smelting of aluminum. The report also discusses the opportunities, barriers, and issues associated with these technologies from a technical, environmental, and economic viewpoint.

  13. Comparison of fluvial suspended-sediment concentrations and particle-size distributions measured with in-stream laser diffraction and in physical samples

    Science.gov (United States)

    Czuba, Jonathan A.; Straub, Timothy D.; Curran, Christopher A.; Landers, Mark N.; Domanski, Marian M.

    2015-01-01

    Laser-diffraction technology, recently adapted for in-stream measurement of fluvial suspended-sediment concentrations (SSCs) and particle-size distributions (PSDs), was tested with a streamlined (SL), isokinetic version of the Laser In-Situ Scattering and Transmissometry (LISST) for measuring volumetric SSCs and PSDs ranging from 1.8-415 µm in 32 log-spaced size classes. Measured SSCs and PSDs from the LISST-SL were compared to a suite of 22 datasets (262 samples in all) of concurrent suspended-sediment and streamflow measurements using a physical sampler and acoustic Doppler current profiler collected during 2010-12 at 16 U.S. Geological Survey streamflow-gaging stations in Illinois and Washington (basin areas: 38 – 69,264 km2). An unrealistically low computed effective density (mass SSC / volumetric SSC) of 1.24 g/ml (95% confidence interval: 1.05-1.45 g/ml) provided the best-fit value (R2 = 0.95; RMSE = 143 mg/L) for converting volumetric SSC to mass SSC for over 2 orders of magnitude of SSC (12-2,170 mg/L; covering a substantial range of SSC that can be measured by the LISST-SL) despite being substantially lower than the sediment particle density of 2.67 g/ml (range: 2.56-2.87 g/ml, 23 samples). The PSDs measured by the LISST-SL were in good agreement with those derived from physical samples over the LISST-SL's measureable size range. Technical and operational limitations of the LISST-SL are provided to facilitate the collection of more accurate data in the future. Additionally, the spatial and temporal variability of SSC and PSD measured by the LISST-SL is briefly described to motivate its potential for advancing our understanding of suspended-sediment transport by rivers.

  14. On the gravitational instability of an ionized magnetized rotating plasma flowing through a porous medium with other transport processes and the suspended particles

    International Nuclear Information System (INIS)

    Vyas, M.K.; Chhajlani, R.K.

    1989-01-01

    The effects of suspended particles and the finite thermal and electrical conductivities on the magnetogravitational instability of an ionized rotating plasma through a porous medium have been investigated, under varying assumptions of the rotational axis and the modes of propagation. In all the cases it is observed that the Jeans' criterion determines the condition of instability with some modifications due to various parameters. The effects of rotation, the medium porosity, and the mass concentration of the suspended particles on instability condition have been removed by (1) magnetic field for longitudinal mode of propagation with perpendicular rotational axis, and (2) viscosity for transverse propagation with rotational axis parallel to the magnetic field. The mass concentration reduces the effects of rotation. Thermal conductivity replaces the adiabatic velocity of sound by the isothermal one, whereas the effect of the finite electrical conductivity is to delink the alignment between the magnetic field and the plasma. Porosity reduces the effects of both the magnetic field and the rotation, on Jeans' criterion. (author)

  15. Erosion of common structural materials and the degradation of suspended particles in flowing suspension of graphite powder in carbon dioxide gas

    International Nuclear Information System (INIS)

    Garton, D.A.; Hawes, R.I.; Rose, P.W.

    1968-06-01

    Experiments have been performed to examine the erosion of common materials of construction by a flowing suspension of graphite powder in carbon dioxide gas and the degradation of the graphite powder in the suspension. The suspension was circulated through a stainless steel loop at a pressure of 200 p.s.i.g. and bulk fluid temperature of 100-150 deg. C. No change in the weight of pins of mild steel, stainless steel and zircaloy, which were placed across the flow stream in a region where the velocity approached 100 ft./sec, could be detected after 350 hours of circulation. Examination of micro-photographs of the cross sections of the specimens showed no change in the structure of the metals. Considerable erosion of graphite pins producing a 6% decrease in the weight was observed under similar conditions. Detailed spectrographic analysis of the suspended powder taken at various times during the experiment showed no noticeable increase in the impurity content which could be attributed to erosion of the test specimens. A considerable increase in the tungsten, tin and cobalt concentration was observed and this is attributed to wear of the pump seal surfaces. The mean particle size of the suspended graphite powder was observed to decrease rapidly from 5 microns to 3 microns after only a few hours of circulation in the loop. After this initial period there was little further change in the particle size, the mean diameter being 2.85 microns after 167 hours of circulation. (author)

  16. Influence of microorganism content in suspended particles on the particle–water partitioning of mercury in semi-enclosed coastal waters

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jiyi [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of); Global Bioresources Research Center, Korea Institute of Ocean Science and Technology (KIOST), Ansan 426-744 (Korea, Republic of); Kim, Hyunji [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of); Han, Seunghee, E-mail: shan@gist.ac.kr [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of)

    2014-02-01

    It is known that particle scavenging of mercury (Hg) can be affected by the abundance of particulate organic matter in coastal waters. However, the role of living organic particles in Hg scavenging is not yet completely understood. In this study, we hypothesized that an abundance of living organic particles (i.e., phytoplankton and bacteria) would influence the particle–water partitioning of Hg in coastal waters. Surface seawater samples were collected from eight stations in Gwangyang Bay, Korea, in three seasons (November 2009, April 2010, and October 2010) for the determination of concentrations of suspended particulate matter (including chlorophyll-a and bacteria), and Hg in unfiltered and filtered waters. We found that more Hg partitioned toward particulate matter when phytoplankton biomass, indicated from the chlorophyll-a concentration in a particle, was higher. In the low algal season, when [chlorophyll-a] < 0.6 μg L{sup −1}, the bacterial number, instead of chlorophyll-a concentration in particle, showed a positive correlation with the particle–water partition coefficient of Hg. Overall, microbial abundance seems to play a critical role in particle scavenging of Hg in coastal water. Taking this result in light of Hg in pristine coastal zones, we predict that increases in algal biomass amplify the potential for algae to transfer Hg to marine food chains. - Highlights: • Abundance of phytoplankton and bacteria influenced particle–water partitioning of Hg. • More Hg partitioned toward particles when microorganism biomass in particle is large. • Increases of algal biomass may enhance Hg bioaccumulation in coastal ecosystem.

  17. Suspended ceilings

    Energy Technology Data Exchange (ETDEWEB)

    Talamo, C.

    1991-05-01

    The retrofitting of existing conventional ceiling systems to suspended ceiling type systems represents an interesting energy savings solution since this method, in addition to providing additional protection against space heat loss and thermal bridges, also creates the possibility of housing, in the void, additional mechanical and electrical lines which may be necessary due to other savings interventions. This paper reviews the various suspended ceiling systems (e.g., those making use of mineral fibre, gypsum panels, wood, vermiculite, etc.) currently marketed in Europe, and reports, for each, some key technical, economic and architectural advantages which include thermal efficiency, noise abatement, as well as, resistance to fire and humidity. Information is also given on the relative installation and maintenance requirements.

  18. Inert gas thrusters

    Science.gov (United States)

    Kaufman, H. R.; Robinson, R. S.

    1980-01-01

    Some advances in component technology for inert gas thrusters are described. The maximum electron emission of a hollow cathode with Ar was increased 60-70% by the use of an enclosed keeper configuration. Operation with Ar, but without emissive oxide, was also obtained. A 30 cm thruster operated with Ar at moderate discharge voltages give double-ion measurements consistent with a double ion correlation developed previously using 15 cm thruster data. An attempt was made to reduce discharge losses by biasing anodes positive of the discharge plasma. The reason this attempt was unsuccessful is not yet clear. The performance of a single-grid ion-optics configuration was evaluated. The ion impingement on the single grid accelerator was found to approach the value expected from the projected blockage when the sheath thickness next to the accelerator was 2-3 times the aperture diameter.

  19. Effects of suspended particles on the rate of mass transfer to a rotating disk electrode. [Ferric cyanide

    Energy Technology Data Exchange (ETDEWEB)

    Roha, D.J.

    1981-06-01

    Limiting currents for the reduction of ferric cyanide at a rotating disk were determined in the presence of 0 to 40 percent by volume of spherical glass beads. Experiments were conducted with six different particle diameters, and with rotation speeds in the range of 387 to 270 rpm, usong both a 0.56 cm and a 1.41 cm radius disk electrode. It was established that at a given rpm upon addition of glass beads in the limiting current, i/sub L/, may increase to more than three times its value without solids. This increase in limiting current density is greater at high rotation speeds and with the larger disk electrode. i/sub L/ as a function of particle diameter yields at maximum at approx. 10 ..mu..m. Two mass transfer models are offered to explain this behavior, both of which assume that the beads are in contact with the disk electrode and moving parallel to its surface. In the surface renewal model it is assumed that complete mixing takes place with the passage of each bead and the boundary layer is replaced with fresh bulk solution. While with the particle film model it is assumed the bead and a clinging film of fluid rotate together. The film promotes mass transfer by alternately absorbing and desorbing the diffusing species. The particle film model best explains the observed behavior of the limiting current density. Calculations of stirring power required verses i/sub L/ observed, show that adding beads to increase i/sub L/ consumes less additional power than simply increasing the rotation speed alone and even permits a decrease in the amount of stirring energy required per unit reactant consumed, at limiting current conditions.

  20. Inerting ballast tanks

    Energy Technology Data Exchange (ETDEWEB)

    Baes, Gabriel L.; Bronneberg, Jos [SBM Offshore, AA Schiedam (Netherlands); Barros, Maria A.S.D. de [Universidade Estadual de Maringa (UEM), PR (Brazil)

    2012-07-01

    This report expands upon the work conducted by SBM Offshore to develop a tank preservation treatment, which is intended to achieve a service life of 30 years. This work focuses on the corrosion problems, in the ballast tanks, based on new built hulls, both for the Gas Exploration Market, the FLNG - Floating Liquefied Natural Gas, and for the Oil Exploration market - FPSO's - Floating Production Storage and offloading Units. Herein, the corrosion rate input comes from the various references related to the process of nitrogen injection, which is expected to extend the vessel's time life. The essential elements of this solution comprise the deoxygenation process, corrosion models, coating effects, tests from laboratory, shipboard tests, corrosion institutes and regulations applicable to the operation. The best corrosion protection system for ballast tanks area combines a coating system and an inert gas system. The condition of the tanks will be dependent upon the level of protection applied to the steel structure, including, but not limited to coating, cathodic protection, etc. There is a need for products which extend the life time. It is not sufficient, only have good theoretical base for the corrosion and an excellent treatment system. In addition, the design of the ships structure must also eliminate the presence of local stress concentrations which can result in fatigue cracking and rupture of the protective coating barrier starting the corrosion. As a direct result of this, more problems in corrosion can be mitigated, vessels can have a better corrosion performance with less maintenance and repairs to coating systems in ballast tanks. Furthermore ships will be positively impacted operationally due to less frequent dry docking. There is a huge potential in the application of inert gas to combat the corrosion rate inside the ballast tanks, one of the most corrosive environments on earth. This application can have a direct impact on vessel structure

  1. Determination of physical and dynamic properties of suspended particles in water column with ultrasonic scanning in between the water surface and stable sediment layer.

    Science.gov (United States)

    Acar, Dursun; Alpar, Bedri; Ozeren, Sinan; Cagatay, Namık; Sari, Erol; Vardar, Denizhan; Eris, Kadir

    2015-04-01

    The behavior of seafloor sediment with its water column should be known against any occurrences of anoxic or oxic conditions. The most important ones of these conditions are possible leakage of natural gas or escape of liquids from sediment. On the basis of combined solid/liquid flow dynamics in sedimentation, such kind of events can change, even in an effective manner, the dynamic movements of molecules and their cumulative mass of particules, i.e. the suspended materials. The deployment of suitable sediment traps or ultrasonic transducers somewhere in the water column are not easy attempts in order to obtain useful information about the state of suspended materials during sedimentation. These are usually bulky instruments; therefore they may behave like an anti-move suppresser on the particles moving in the float direction, in oxic and anoxic manner. These instruments, on the other hand, may cover the effects of diffusive flow or bubble formed gas and fluid escape from the sediment surface into the water column. Ultrasonic scanners, however, are able to make observations in a remote manner, without affecting such artificial events. Our field trials were successfully completed at the historical estuary called Halic of Marmara sea . The physical properties; such as the velocity of particles, their travel directions, their dimensions and the ability to observe anti-compositor crushes of shock waves of the bubbles are only a few of these observations in natural ambience. The most important problem solved about water pressure during 3 atmosphere . The sensor has been tested successfully few times. We used the ''High voltage electric isolator oil filling'' to the inside of the scanner for pressure equalization between outer side and inner body of probe at a depth of (20 meters) beneath the sea surface . The transmitted signals by the planar crystal of the transducer become weaker under the pressure of overlying water column in depths. Our efforts are now focused on the

  2. Optical Characterisation of Suspended Particles in the Mackenzie River Plume (Canadian Arctic Ocean) and Implications for Ocean Colour Remote Sensing

    Science.gov (United States)

    Doxaran, D.; Ehn, J.; Belanger, S.; Matsuoka, A.; Hooker, S.; Babin, M.

    2012-01-01

    Climate change significantly impacts Arctic shelf regions in terms of air temperature, ultraviolet radiation, melting of sea ice, precipitation, thawing of permafrost and coastal erosion. Direct consequences have been observed on the increasing Arctic river flow and a large amount of organic carbon sequestered in soils at high latitudes since the last glacial maximum can be expected to be delivered to the Arctic Ocean during the coming decade. Monitoring the fluxes and fate of this terrigenous organic carbon is problematic in such sparsely populated regions unless remote sensing techniques can be developed and proved to be operational. The main objective of this study is to develop an ocean colour algorithm to operationally monitor dynamics of suspended particulate matter (SPM) on the Mackenzie River continental shelf (Canadian Arctic Ocean) using satellite imagery. The water optical properties are documented across the study area and related to concentrations of SPM and particulate organic carbon (POC). Robust SPM and POC : SPM proxies are identified, such as the light backscattering and attenuation coefficients, and relationships are established between these optical and biogeochemical parameters. Following a semi-analytical approach, a regional SPM quantification relationship is obtained for the inversion of the water reflectance signal into SPM concentration. This relationship is reproduced based on independent field optical measurements. It is successfully applied to a selection of MODIS satellite data which allow estimating fluxes at the river mouth and monitoring the extension and dynamics of the Mackenzie River surface plume in 2009, 2010 and 2011. Good agreement is obtained with field observations representative of the whole water column in the river delta zone where terrigenous SPM is mainly constrained (out of short periods of maximum river outflow). Most of the seaward export of SPM is observed to occur within the west side of the river mouth. Future

  3. Light Absorption by Suspended Particles in the Red Sea: Effect of Phytoplankton Community Size Structure and Pigment Composition

    Science.gov (United States)

    Kheireddine, Malika; Ouhssain, Mustapha; Organelli, Emanuele; Bricaud, Annick; Jones, Burton H.

    2018-02-01

    The light absorption properties of phytoplankton (aph(λ)) and nonalgal particles (anap(λ)) associated with phytoplankton pigments were analyzed across the Red Sea, in the upper 200 m depth, between October 2014 and August 2016. The contribution by nonalgal particles to the total particulate light absorption (aph(λ) + anap(λ)) was highly variable (23 ± 17% at 440 nm) and no relationship between anap(440) and chlorophyll a concentration, [TChl a], was observed. Phytoplankton-specific phytoplankton absorption coefficients at 440 and 676 nm for a given [TChl a], aph*(440), and aph∗(676) were slightly higher than those derived from average relationships for open ocean waters within the surface layer as well as along the water column. Variations in the concentration of photosynthetic and photoprotective pigments were noticeable by changes in phytoplankton community size structure as well as in aph∗(λ). This study revealed that a higher proportion of picophytoplankton and an increase in photoprotective pigments (mainly driven by zeaxanthin) tended to be responsible for the higher aph∗(λ) values found in the Red Sea as compared to other oligotrophic regions with similar [TChl a]. Understanding this variability across the Red Sea may help improve the accuracy of biogeochemical parameters, such as [TChl a], derived from in situ measurements and ocean color remote sensing at a regional scale.

  4. Light Absorption by Suspended Particles in the Red Sea: Effect of Phytoplankton Community Size Structure and Pigment Composition

    KAUST Repository

    Kheireddine, Malika

    2018-01-10

    The light absorption properties of phytoplankton (aph(λ)) and non-algal particles (anap(λ)) associated with phytoplankton pigments were analyzed across the Red Sea, in the upper 200 m depth, between October 2014 and August 2016. The contribution by non-algal particles to the total particulate light absorption (aph(λ)+ anap(λ)) was highly variable (23 ± 17% at 440 nm) and no relationship between anap(440) and chlorophyll a concentration, [TChl a], was observed. Phytoplankton specific phytoplankton absorption coefficients at 440 and 676 nm for a given [TChl a], aph*(440) and aph*(676), were slightly higher than those derived from average relationships for open ocean waters within the surface layer as well as along the water column. Variations in the concentration of photosynthetic and photoprotective pigments were noticeable by changes in phytoplankton community size structure as well as in aph*(λ). This study revealed that a higher proportion of picophytoplankton and an increase in photoprotective pigments (mainly driven by zeaxanthin) tended to be responsible for the higher aph*(λ) values found in the Red Sea as compared to other oligotrophic regions with similar [TChl a]. Understanding this variability across the Red Sea may help improve the accuracy of biogeochemical parameters, such as [TChl a], derived from in situ measurements and ocean color remote sensing at a regional scale.

  5. Light Absorption by Suspended Particles in the Red Sea: Effect of Phytoplankton Community Size Structure and Pigment Composition

    KAUST Repository

    Kheireddine, Malika; Ouhssain, Mustapha; Organelli, Emanuele; Bricaud, Annick; Jones, Burton

    2018-01-01

    The light absorption properties of phytoplankton (aph(λ)) and non-algal particles (anap(λ)) associated with phytoplankton pigments were analyzed across the Red Sea, in the upper 200 m depth, between October 2014 and August 2016. The contribution by non-algal particles to the total particulate light absorption (aph(λ)+ anap(λ)) was highly variable (23 ± 17% at 440 nm) and no relationship between anap(440) and chlorophyll a concentration, [TChl a], was observed. Phytoplankton specific phytoplankton absorption coefficients at 440 and 676 nm for a given [TChl a], aph*(440) and aph*(676), were slightly higher than those derived from average relationships for open ocean waters within the surface layer as well as along the water column. Variations in the concentration of photosynthetic and photoprotective pigments were noticeable by changes in phytoplankton community size structure as well as in aph*(λ). This study revealed that a higher proportion of picophytoplankton and an increase in photoprotective pigments (mainly driven by zeaxanthin) tended to be responsible for the higher aph*(λ) values found in the Red Sea as compared to other oligotrophic regions with similar [TChl a]. Understanding this variability across the Red Sea may help improve the accuracy of biogeochemical parameters, such as [TChl a], derived from in situ measurements and ocean color remote sensing at a regional scale.

  6. Origins of inert Higgs doublets

    Directory of Open Access Journals (Sweden)

    Thomas W. Kephart

    2016-05-01

    Full Text Available We consider beyond the standard model embedding of inert Higgs doublet fields. We argue that inert Higgs doublets can arise naturally in grand unified theories where the necessary associated Z2 symmetry can occur automatically. Several examples are discussed.

  7. Mn nanoparticles produced by inert gas condensation

    International Nuclear Information System (INIS)

    Ward, M B; Brydson, R; Cochrane, R F

    2006-01-01

    The results from experiments using the inert gas condensation method to produce nanoparticles of manganese are presented. Structural and compositional data have been collected through electron diffraction, EDX (energy dispersive X-ray) and EELS (electron energy loss spectroscopy). Both Mn 3 O 4 and pure Mn particles have been produced. Moisture in untreated helium gas causes the particles to oxidize, whereas running the helium through a liquid nitrogen trap removes the moisture and produces β-Mn particles in a metastable state. The particle sizes and the size distribution have been determined. Particle sizes range from 2nm to above 100 nm, however the majority of particles lie in the range below 20 nm with a modal particle size of 6 nm. As well as the modal particle size of 6 nm, there is another peak in the frequency curve at 16 nm that represents another group particles that lie in the range 12 to 20 nm. The smaller particles are single crystals, but the larger particles appear to have a dense region around their edge with a less dense centre. Determination of their exact nature is ongoing

  8. Assessment of the relationship between total suspended particles and the response of two biological indicators transplanted to an urban area in central Argentina

    Science.gov (United States)

    Carreras, H. A.; Rodriguez, J. H.; González, C. M.; Wannaz, E. D.; Garcia Ferreyra, F.; Perez, C. A.; Pignata, M. L.

    Samples of the vascular plant Tradescantia pallida and the lichen Usnea amblyoclada were exposed from October 2004 to April 2005 in three sites with different local sources of air pollution in Córdoba city, Argentina. Simultaneous determinations of the ambient levels of total suspended particles were made for each site. Young inflorescenses of T. pallida were collected in November, February and April and the frequency of micronuclei was determined on early tetrads of pollen mother cells. Physiological parameters and the elemental composition of lichen thalli were measured from samples exposed and replaced every month. Significant differences among sampling sites were observed in the frequency of micronuclei measured in T. pallida as well as in many physiological parameters and elements accumulated in lichen thalli. The mass of particulate material as well as the concentration of Ca, Mn, Cu, Zn and Sr was significantly different in different sampling sites, too. These results suggest that in situ biomonitoring using both higher plants and lichens may be of use to characterize air pollution in areas devoid of instrumental monitoring techniques or where it is necessary to explore the distribution of air contaminants at a microscale.

  9. Seasonal and spatial variations of rare earth elements in rainwaters, river waters and total suspended particles in air in South Korea

    International Nuclear Information System (INIS)

    Ryu, J.S.; Lee, K.S.; Lee, S.G.; Lee, D.; Chang, H.W.

    2007-01-01

    In order to investigate the seasonal and spatial variations of rare earth element (REE) concentrations in natural waters in the central part of South Korea, rain and river waters were collected during 2003-2004. Total suspended particles (TSP) in air were also sampled to investigate the effect of the Asian dust (the Yellow sand) on the chemistry of rainwaters. All samples showed that the absolute concentrations of the light REEs (LREEs) were higher than those of the heavy REEs (HREEs). The post-Archean Australian shale (PAAS)-normalized REE patterns indicate that the REEs in TSP and rainwaters were affected by Asian dust and anthropogenic contaminant, whereas those of river waters were mainly controlled by the geology of their drainage basin and seasonal changes in water regime. The calculated fluxes and yields of total REEs (REEs plus Y) in the South Han River were much greater than those in the North Han River due to the more widespread distribution of sedimentary rocks in the drainage area and more efficient chemical weathering

  10. INERT GAS SHIELD FOR WELDING

    Science.gov (United States)

    Jones, S.O.; Daly, F.V.

    1958-10-14

    S>An inert gas shield is presented for arc-welding materials such as zirconium that tend to oxidize rapidly in air. The device comprises a rectangular metal box into which the welding electrode is introduced through a rubber diaphragm to provide flexibility. The front of the box is provided with a wlndow having a small hole through which flller metal is introduced. The box is supplied with an inert gas to exclude the atmosphere, and with cooling water to promote the solidification of the weld while in tbe inert atmosphere. A separate water-cooled copper backing bar is provided underneath the joint to be welded to contain the melt-through at the root of the joint, shielding the root of the joint with its own supply of inert gas and cooling the deposited weld metal. This device facilitates the welding of large workpieces of zirconium frequently encountered in reactor construction.

  11. TIG (Tungsten Inert Gas) welding

    International Nuclear Information System (INIS)

    Anon.

    2010-01-01

    After having recalled the Tungsten Inert Gas process principle and the different alternative TIG processes, the author explains the advantages and limits of this process. The applications and recent developments are given. (O.M.)

  12. Removal of antibiotics from water in the coexistence of suspended particles and natural organic matters using amino-acid-modified-chitosan flocculants: A combined experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Shuying [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Yang, Zhen, E-mail: yangzhen@njnu.edu.cn [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Ren, Kexin [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Tian, Ziqi [Department of Chemistry, University of California, Riverside, CA 92521 (United States); Dong, Chang; Ma, Ruixue; Yu, Ge [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China); Yang, Weiben, E-mail: yangwb007@njnu.edu.cn [School of Chemistry and Materials Science, Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, Nanjing Normal University, Nanjing 210023 (China)

    2016-11-05

    Highlights: • Novel amino-acid-modified-chitosan flocculants are employed to remove antibiotics. • Effects of different structures of amino acids and antibiotics are investigated. • Correlation analysis shows coexisted kaolin and HA have synergistic removal effect. • Theoretical DFT calculation clarifies the interactions in molecular level. - Abstract: Contamination of trace antibiotics is widely found in surface water sources. This work delineates removal of trace antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) or tylosin (TYL)) from synthetic surface water by flocculation, in the coexistence of inorganic suspended particles (kaolin) and natural organic matter (humic acid, HA). To avoid extra pollution caused by petrochemical products-based modification reagents, environmental-friendly amino-acid-modified-chitosan flocculants, Ctrp and Ctyr, with different functional aromatic-rings structures were employed. Jar tests at various pHs exhibited that, Ctyr, owning phenol groups as electron donors, was favored for elimination of cationic NOR (∼50% removal; optimal pH: 6; optimal dosage: 4 mg/L) and TYL (∼60% removal; optimal pH: 7; optimal dosage: 7.5 mg/L), due to π–π electron donator-acceptor (EDA) effect and unconventional H-bonds. Differently, Ctrp with indole groups as electron acceptor had better removal rate (∼50%) of SDZ anions (electron donator). According to correlation analysis, the coexisted kaolin and HA played positive roles in antibiotics’ removal. Detailed pairwise interactions in molecular level among different components were clarified by spectral analysis and theoretical calculations (density functional theory), which are important for both the structural design of new flocculants aiming at targeted contaminants and understanding the environmental behaviors of antibiotics in water.

  13. Removal of antibiotics from water in the coexistence of suspended particles and natural organic matters using amino-acid-modified-chitosan flocculants: A combined experimental and theoretical study

    International Nuclear Information System (INIS)

    Jia, Shuying; Yang, Zhen; Ren, Kexin; Tian, Ziqi; Dong, Chang; Ma, Ruixue; Yu, Ge; Yang, Weiben

    2016-01-01

    Highlights: • Novel amino-acid-modified-chitosan flocculants are employed to remove antibiotics. • Effects of different structures of amino acids and antibiotics are investigated. • Correlation analysis shows coexisted kaolin and HA have synergistic removal effect. • Theoretical DFT calculation clarifies the interactions in molecular level. - Abstract: Contamination of trace antibiotics is widely found in surface water sources. This work delineates removal of trace antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) or tylosin (TYL)) from synthetic surface water by flocculation, in the coexistence of inorganic suspended particles (kaolin) and natural organic matter (humic acid, HA). To avoid extra pollution caused by petrochemical products-based modification reagents, environmental-friendly amino-acid-modified-chitosan flocculants, Ctrp and Ctyr, with different functional aromatic-rings structures were employed. Jar tests at various pHs exhibited that, Ctyr, owning phenol groups as electron donors, was favored for elimination of cationic NOR (∼50% removal; optimal pH: 6; optimal dosage: 4 mg/L) and TYL (∼60% removal; optimal pH: 7; optimal dosage: 7.5 mg/L), due to π–π electron donator-acceptor (EDA) effect and unconventional H-bonds. Differently, Ctrp with indole groups as electron acceptor had better removal rate (∼50%) of SDZ anions (electron donator). According to correlation analysis, the coexisted kaolin and HA played positive roles in antibiotics’ removal. Detailed pairwise interactions in molecular level among different components were clarified by spectral analysis and theoretical calculations (density functional theory), which are important for both the structural design of new flocculants aiming at targeted contaminants and understanding the environmental behaviors of antibiotics in water.

  14. Long-term observation of water-soluble chemical components and acid-digested metals in the total suspended particles collected at Okinawa, Japan

    Science.gov (United States)

    Handa, D.; Okada, K.; Kuroki, Y.; Nakama, Y.; Nakajima, H.; Somada, Y.; Ijyu, M.; Azechi, S.; Oshiro, Y.; Nakaema, F.; Miyagi, Y.; Arakaki, T.; Tanahara, A.

    2011-12-01

    The economic growth and population increase in recent Asia have been increasing air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asia's air quality because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background clean air and can be compared with continental air masses which have been affected by anthropogenic activities. We collected total suspended particles (TSP) on quartz filters by using a high volume air sampler at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS), Okinawa, Japan during August 2005 and August 2010. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations, water-soluble organic carbon (WSOC) and acid-digested metals in TSP samples using ion chromatography, atomic absorption spectrometry, total organic carbon analyzer and Inductively Coupled Plasma Mass spectrometry (ICP-MS), respectively. Seasonal variation of water-soluble chemical components and acid-digested metals showed that the concentrations were the lowest in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian continent, the concentrations of water-soluble chemical components and acid-digested metals were much higher compared to the other directions, suggesting long-range transport of air pollutants from Asian continent. Also, when the air mass came from Asian continent (75-100% dominant), the mean concentrations of non-sea salt sulfate and nitrate increased ca. 1.8 times and ca. 3.7 times, respectively between 2005 and 2010, and the ratio of nitrate to

  15. Sampling of suspended particulate matter using particle traps in the Rhône River: Relevance and representativeness for the monitoring of contaminants.

    Science.gov (United States)

    Masson, M; Angot, H; Le Bescond, C; Launay, M; Dabrin, A; Miège, C; Le Coz, J; Coquery, M

    2018-05-10

    Monitoring hydrophobic contaminants in surface freshwaters requires measuring contaminant concentrations in the particulate fraction (sediment or suspended particulate matter, SPM) of the water column. Particle traps (PTs) have been recently developed to sample SPM as cost-efficient, easy to operate and time-integrative tools. But the representativeness of SPM collected with PTs is not fully understood, notably in terms of grain size distribution and particulate organic carbon (POC) content, which could both skew particulate contaminant concentrations. The aim of this study was to evaluate the representativeness of SPM characteristics (i.e. grain size distribution and POC content) and associated contaminants (i.e. polychlorinated biphenyls, PCBs; mercury, Hg) in samples collected in a large river using PTs for differing hydrological conditions. Samples collected using PTs (n = 74) were compared with samples collected during the same time period by continuous flow centrifugation (CFC). The grain size distribution of PT samples shifted with increasing water discharge: the proportion of very fine silts (2-6 μm) decreased while that of coarse silts (27-74 μm) increased. Regardless of water discharge, POC contents were different likely due to integration by PT of high POC-content phytoplankton blooms or low POC-content flood events. Differences in PCBs and Hg concentrations were usually within the range of analytical uncertainties and could not be related to grain size or POC content shifts. Occasional Hg-enriched inputs may have led to higher Hg concentrations in a few PT samples (n = 4) which highlights the time-integrative capacity of the PTs. The differences of annual Hg and PCB fluxes calculated either from PT samples or CFC samples were generally below 20%. Despite some inherent limitations (e.g. grain size distribution bias), our findings suggest that PT sampling is a valuable technique to assess reliable spatial and temporal trends of particulate

  16. The Inert and the Noble

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 3. The Inert and the Noble. A G Samuelson. Article-in-a-Box Volume 4 Issue 3 March 1999 pp 3-5 ... Author Affiliations. A G Samuelson1. Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, India.

  17. 40 CFR 230.21 - Suspended particulates/turbidity.

    Science.gov (United States)

    2010-07-01

    ... Impacts on Physical and Chemical Characteristics of the Aquatic Ecosystem § 230.21 Suspended particulates/turbidity. (a) Suspended particulates in the aquatic ecosystem consist of fine-grained mineral particles..., and man's activities including dredging and filling. Particulates may remain suspended in the water...

  18. Assessment of the Atmospheric Suspended Particles Pollution in the Madrid Air Quality Networks; Evaluacion de la Contaminacion Atmosferica producida por Particulas en Suspension en las Redes de Calidad del Aire de la Comunidad de Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, P; Artinano, B

    2000-07-01

    Suspended particles are a very complex type of atmospheric pollution because of their chemical composition and size. In fact, there are a quite high number of particles sources which are linked to different physico-chemical processes that determine their size. At present particles smaller than 10 {mu}m are considered the most dangerous, as has been recently pointed out by numerous epidemiologic studies. In this way, more restrictive concentration limit values have been approved in the EU countries, so an assessment of present airborne concentration values and the sources apportionment in their most representative areas is needed. In the Madrid Community a first approaching of these and other aims, has been carried out from an analysis of the Madrid Air Quality networks data. This will contribute to the stablishment of concentration levels abatement strategies. (Author) 111 refs.

  19. Comparison of laser-light diffraction method with other methods of analyzing the particle size distribution in suspensions of latex, pollen, and quartz, and in suspended particulate matter in river water

    International Nuclear Information System (INIS)

    Heyn, R.D.; Zimmermann, H.U.

    1983-01-01

    This report gives an idea of different methods being used for the particle size analysis, including a laser light diffraction method and an image analysis method. These comparing measurements have been carried out with suspensions consisting of fresh water and standard particles, ranging between 1 and 100 μm, as well as with suspended particulate matter of the Elbe river. As to standard particles, statistical errors are subject to the width of the size distribution. When using the light diffraction method, the errors vary between 0,7 and 16%, however, when applying the image analysis method, they range between 0,5 and 26%. As a result of the measurements of the suspended particulate matter of the Elbe river, a statistical error of 21% has occured with regard to the image analysis method, whilst the light diffraction method has shown an error of about 4 - 11%. Possible reasons for systematical and random errors have been discussed as to both of these methods. (orig.) [de

  20. Synthesis and tissue distribution studies of two novel esters of haloperidol and the application of radiolabelling techniques using short-lived radionuclides in the study of the deposition characteristics of suspended aerosol particles

    International Nuclear Information System (INIS)

    Smith, M.F.

    1982-01-01

    In the present work, the Schotten-Baumann reaction conditions were modified to esterify the tertiary hydroxyl group of haloperidol. The rapid synthesis (less than 20 min) makes this procedure applicable to the preparation of esters of haloperidol containing fluorine-18 (t/sup (1/2)/ 110 min), a γ-emitting radioisotope useful in external scintigraphy. In vivo distribution studies of the synthesized tritiated esters and haloperidol in the rat demonstrated that neither ester prodrug achieved overall higher brain concentration levels than haloperidol. In this study, radiotracer techniques were developed to examine parameters that characterize pressurized aerosols designed to utilize insoluble particles suspended in the aerosol formulation. The suspended micro-aggregated bovine albumin microspheres were labelled with iodine-131 (t/sup (1/2)/ 8 days). The techniques developed illustrate the use of short-lived radionuclides for: 1) quantitation of each metered dose; 2) characterization of particle size distribution by the aerosol; and 3) determination of the extent of deposition of the particles in the aerosol and all of its components

  1. Radiochemical and inert gas analyses

    International Nuclear Information System (INIS)

    Andrews, J.N.

    1985-01-01

    The subject is discussed under the headings: introduction (radioelement solution in groundwaters; U and Th; Ra and Rn; atmospheric and radiogenic solution in groundwaters; atmosphere derived gases; radiogenic helium; radiogenic argon; biogenic gases); analytical methods (sampling; U-content and 234 U/ 238 U activity ratio; 222 Ru; 226 Ra; dissolved inert gases; 4 He in core samples); the gamma spectrometric determination of U,Th and K. Results are presented and discussed. (U.K.)

  2. 46 CFR 153.923 - Inerting systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Inerting systems. 153.923 Section 153.923 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Requirements § 153.923 Inerting systems. The master shall ensure that the inert gas systems for any cargo that...

  3. Inert carriers for column extraction chromatography

    International Nuclear Information System (INIS)

    Katykhin, G.S.

    1978-01-01

    Inert carriers used in column extraction chromatography are reviewed. Such carriers are devided into two large groups: hydrophilic carriers which possess high surface energy and are well wetted only with strongly polar liquids (kieselguhrs, silica gels, glasses, cellulose, Al 2 O 3 ) and water-repellent carriers which possess low surface energy and are well wetted with various organic solvents (polyethylene, polytetrafluorethylene polytrifluorochlorethylene). Properties of various carriers are presented: structure, chemical and radiation stability, adsorption properties, extracting agent capacity. The effect of structure and sizes of particles on the efficiency of chromatography columns is considered. Ways of immovable phase deposition on the carrier and the latter's regeneration. Peculiarities of column packing for preparative and continuous chromatography are discussed

  4. Transport of suspended matter through rock formations

    International Nuclear Information System (INIS)

    Wahlig, B.G.

    1980-01-01

    It may be hypothesized that significant quantities of some waste nuclides could be adsorbed on the surfaces of particles suspended in the flowing groundwater and thereby migrate farther or faster than they would in dissolved form. This thesis deals with one aspect of this proposed migration mechanism, the transport of suspended matter through rock formations. A theoretical examination of the forces effecting suspended particles in flowing groundwater indicates that only two interaction energies are likely to be significant compared to the particles' thermal energies. The responsible interactions are van der Waals attraction between the particles and the rock, and electrolytic double-layer repulsion between the atmospheres of ions near the surfaces of the particles and the rock. This theoretical understanding was tested in column flow adsorption experiments using fine kaolin particles as the suspended matter and crushed basalt as the rock medium. The effects of several parameters on kaolin mobility were explored, including the influences of the following: solution ion concentration, solution cation valence, degree of solution oxygen saturation, solution flow velocity, and degree of rock surface ageing. The experimental results indicate that the migration of suspended matter over kilometer distances in the lithosphere is very unlikely unless the average pore size of the conducting mediumis fairly large (> 1mm), or the flow occurs in large fractures

  5. Laboratory report on iodine (129I and 127I) speciation, transformation and mobility in Handford groundwater, suspended particles and sediments

    Energy Technology Data Exchange (ETDEWEB)

    Santschi, P. H. [Texas A & M Univ., College Station, TX (United States); Xu, C. [Texas A & M Univ., College Station, TX (United States); Zhang, S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Ho, Y. [Texas A & M Univ., College Station, TX (United States); Li, H. [Texas A & M Univ., College Station, TX (United States); Schwehr, K. [Texas A & M Univ., College Station, TX (United States); Kaplan, D. I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2012-09-01

    were on average 89% greater than iodide Kd values, and the Kd values for both species tended to increase with the amount of organic carbon (OC) present in the sediment. It is especially noteworthy that this trend existed at the very low OC concentrations that naturally exist in the Hanford sediments. Iodine and OC can form essentially irreversible covalent bonds, thereby providing a yet unstudied 129I retardation reaction at the Hanford Site. In addition to the transformation of iodine species, the sediment collected from the vadose zone also released stable iodide into the aqueous phase. It was found that the three sediments all took up the ambient iodate from the groundwater and slowly transformed it into iodide under the laboratory conditions, likely dependent on the abundance of reducing agents such as organic matter and Fe2+. Therefore two competitive iodine processes were identified, the tendency for the sediment to reduce iodate to iodide, and the groundwater chemistry to maintain the iodine as iodate, presumably it is largely the result of natural pH and dissolved O2/Eh levels. Suspended carbonate (and silica) particles collected from Hanford groundwater contained elevated amounts of iodine (142 ± 8 μg/g iodine), consisting mainly of iodate (>99%). Iodate was likely incorporated into the carbonate structure during calcite precipitation upon degasing of CO2 as the groundwater samples were removed from the subsurface. This concentration of groundwater iodate in precipitated carbonate has implication to long-term fate and transport of 129I and on active in-situ 129I groundwater remediation. This study provides some of the first groundwater radioiodine speciation studies conducted in arid environments and provides much needed mechanistic descriptions to permit making informed decisions about low-cost/high intellectual input remediation options, such as monitored natural

  6. [Research on the Content Characteristics and Pollution Evaluation of Heavy Metals in Filtered Water and Suspended Particles from Gansu, Ningxia and Inner Mongolia Sections of the Yellow River in Wet Season Using HR-ICP-MS].

    Science.gov (United States)

    Ma, Xiao-ling; Liu, Jing-jun; Deng, Feng-yu; Zuo, Hang; Huang, Fang; Zhang, Li-yang; Liu, Ying

    2015-10-01

    The content characteristics, pollution evaluation and source identification of 6 heavy Metals (Cd, Pb, Cr, As, Cu and Zn) in filtered water and 9 heavy Metals (Cd, Pb, Cr, Ni, Cu, V, Co, Zn and Mn) in suspended particles from 10 sampling sites such as Zhaojunfuqiao (S1) and Baotoufuqiao (S2), etc. from Gansu, Ningxia and Inner Mongolia sections of the Yellow River in 2012 Wet Season were studied to understand the condition of the heavy metal pollution in Gansu, Ningxia and Inner Mongolia Sections of the Yellow River by using high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS). Multivariate geochemical approaches and statistical analysis were also exploited for assessing the level of heavy metals in filtered water and suspended particles from studied area. The results showed that in filtering water, only the concentrations of Cr exceeded the standard value of Environmental Quality Standard for Surface Water (GB3838-2002) and were the highest (74.8-94.7 μg x L(-1)) among all elements in 10 sampling sites; Single factor pollution index (I(i)) results suggested that the water quality in all sampling sites were contaminated by both Cr and total nitrogen (TN), with the exception of TN in Baotoufuqiao (S2); Integrated Nemerow pollution index (I) indicated that the I values in all sampling sites were between 1-2 (light pollution), which implied that the water quality in Gansu, Ningxia and Inner Mongolia sections, especially downstream sections (S1-S6) of the Yellow River wasn't an ideal source for drinking and using in aquaculture any more. In suspended particles, concentrations of heavy metals were relatively higher than their soil background values in 10 sampling sites, except Ni in S10 (34.7 μg x L(-1)). Index of geo-accumulation (I(geo)) indicated that the I(geo) values of Pb, Cr, Ni, Cu, V, Co, Zn and Mn in all sampling sites were less than 1 (unpolluted or unpolluted-moderately polluted), respectively, while I(geo)Cd were the highest in 10

  7. Adsorption and desorption of radioactive inert gases in various materials

    International Nuclear Information System (INIS)

    Butkus, D.

    1999-01-01

    Peculiarities of the 85 Kr and 133 Xe adsorption and desorption processes in active carbon and paraffin are considered in the work. During the desorption process, the distribution of 85 Kr and 133 Xe atoms in active carbon particles is uneven: atoms in narrow micropores desorb the last. It is shown that by changing adsorption conditions the presence time of radioactive inert gases in an active carbon can be prolonged. The adsorption and desorption processes change in the adsorbent, which changes its aggregation state: adsorption occurs in a liquid absorbent and desorption - in a solid absorbent. Paraffin is just such an absorbent changing its aggregation state with low energy losses. It has been obtained that 133 Xe accumulates less in liquid paraffin that in an active carbon. The absorption of 85 Kr in paraffin is larger than in an active carbon (at 18-20 degrees Celsius), while desorption is slower. The velocity of radioactive inert gas atom motion in different places of a solid paraffin sample is different - it increases approaching the borders of the sample. Prolongation of the desorption time of radioactive inert gases from adsorbents and adsorbents in many cases is of a practical importance. In this work, it has been shown by model experiments that the intensity of adsorption and desorption processes for the same sorbents can be changed. Desorption intensity changes are related to the distribution of gas atoms on the surface of particles and in micropores. Desorption velocity decreases if inert gas atoms having entered micropores are 'closed' by condensed liquids in the environment. In this case an inert gas atom diffuses within the whole particle volume or through the condensed liquid. Radioactive inert gases 85 Kr and 133 Xe are absorbed not only in liquid paraffin but in solid one as well. Therefore, after a paraffin sample is hermetically closed in a glass dish, 85 Kr (gas) having diffused from this sample is repeatedly absorbed in it. The 85 Kr

  8. 7 CFR 201.51 - Inert matter.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS Purity Analysis in the Administration of the Act § 201.51 Inert matter. Inert matter shall include... kochia that pass through a 1 mm opening, square-hole sieve, when shaken for 30 seconds. (8) The thin... devoid of the husk and pass through a 1/13th-inch, round-hole sieve. (ii) Bulblets which show evident...

  9. Inert anode containing base metal and noble metal useful for the electrolytic production of aluminum

    Science.gov (United States)

    Ray, Siba P.; Liu, Xinghua

    2000-01-01

    An inert anode for production of metals such as aluminum is disclosed. The inert anode comprises a base metal selected from Cu and Ag, and at least one noble metal selected from Ag, Pd, Pt, Au, Rh, Ru, Ir and Os. The inert anode may optionally be formed of sintered particles having interior portions containing more base metal than noble metal and exterior portions containing more noble metal than base metal. In a preferred embodiment, the base metal comprises Cu, and the noble metal comprises Ag, Pd or a combination thereof.

  10. Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis

    Directory of Open Access Journals (Sweden)

    I. Tolosa

    2013-03-01

    Full Text Available Molecular lipid biomarkers (hydrocarbons, alcohols, sterols and fatty acids and compound-specific isotope analysis of suspended particulate organic matter (SPM and surface sediments of the Mackenzie Shelf and slope (southeast Beaufort Sea, Arctic Ocean were studied in summer 2009. The concentrations of the molecular lipid markers, characteristic of known organic matter sources, were grouped and used as proxies to evaluate the relative importance of fresh algal, detrital algal, fossil, C3 terrestrial plants, bacterial and zooplankton material in the organic matter (OM of this area. Fossil and detrital algal contributions were the major fractions of the freshwater SPM from the Mackenzie River with ~34% each of the total molecular biomarkers. Fresh algal, C3 terrestrial, bacterial and zooplanktonic components represented much lower percentages, 17, 10, 4 and 80%, with a minor contribution of fossil and C3 terrestrial biomarkers. Characterization of the sediments revealed a major sink of refractory algal material mixed with some fresh algal material, fossil hydrocarbons and a small input of C3 terrestrial sources. In particular, the sediments from the shelf and at the mouth of the Amundsen Gulf presented the highest contribution of detrital algal material (60–75%, whereas those from the slope contained the highest proportion of fossil (40% and C3 terrestrial plant material (10%. Overall, considering that the detrital algal material is marine derived, autochthonous sources contributed more than allochthonous sources to the OM lipid pool. Using the ratio of an allochthonous biomarker (normalized to total organic carbon, TOC found in the sediments to those measured at the river mouth water, we estimated that the fraction of terrestrial material preserved in the sediments accounted for 30–40% of the total carbon in the inner shelf sediments, 17% in the outer shelf and Amundsen Gulf and up to 25% in the slope sediments. These estimates are low

  11. Evaluation of the air quality regarding total suspended particles and heavy metals (Pb, Cd, Ni, Cu, Cr) in the Hermosillo city, Sonora, Mexico, during a yearly period

    International Nuclear Information System (INIS)

    Cruz C, M. E.; Quintero N, M.; Gomez A, A.; Varela S, J.

    2013-01-01

    In the present study, the air quality of the city of Hermosillo, Sonora, Mexico was assessed considering total suspended particulates (tsp) and heavy metals (Pb, Cd, Ni, Cu, Cr) from June 2001 through May 2002 in three monitoring sites Centro (Mazon), Nor este (CESUES) and Noroeste (CBTIS). The filter-samples used for that purpose were provided by the Air Quality Evaluation and Improvement Program (PEMCA) of the municipality of Hermosillo. The sampling method was based on high volume sampling frequency set every 6 days with non-simultaneous sampling among the three sampling sites. Filters were dissolved for metal determination by acidic-extraction, and then analyzed by flame atomic absorption spectrophotometry. Results indicate that tsp concentrations at Centro and Noroeste sites were frequently higher than the maximum daily permissible level (260 μg/m 3 ), while in the three sites the annual average was higher than the maximum annual permissible level (75 μg/m 3 ) both established in the standard NOM-024-Ssa-1993 (Ssa 1994a). According to the Air Quality Standard Index (US EPA 1992a), used in Mexico by Air Quality Metropolitan Index (IMECA) the results indicate that the air quality in the city of Hermosillo regarding tsp was placed between no satisfactory and poor. In regard to heavy metals (Pb, Cd, Ni, Cu, Cr), concentrations detected were below the maximum permissible levels and/or criteria taking into account the standard NOM-026-Ssa-1993 (Ssa 1994b), the Who criterion (2000), the European Union criterion (Cec 2003), and the European Environmental Agency criteria (EEA 2004). Such findings would mean that airborne metals are of no concern; however, air quality is still classified as no satisfactory due to high particulate matter concentrations. Keeping air quality parameters monitoring is recommended in order to get extensive data for use in risk studies of air quality and health (morbidity/mortality), as well as topographic conditions, meteorological and

  12. The behaviour of cesium 137, chromium 51, cobalt 60, Manganese 54, sodium 22 and zinc 65 in simulated estuarine environments. Effects of suspended mineral particles and dissolved organic matters

    International Nuclear Information System (INIS)

    Mahler, P.

    1985-09-01

    This laboratory investigation studied the retention of 6 radionuclides (cesium 137, chrome 51, cobalt 60, manganese 54, sodium 22 and zinc 65) on three types of clay particles (kaolinite, illite, montmorillonite) and on sediments, suspended in media with salinities ranging between 0 and 34 per mill, with or without organic matters. Measurement of the radioactivity retained by the particles after 5 days' contact with the radionuclide made it possible to calculate the percentages retained and the distribution coefficients, and to follow their evolution versus salinity. Parallel experiments studied the behaviours of the 6 radionuclides as a function of experimental factors (wall effect, contact time..). An exhaustive bibliographic review gives the state-of-the-art of the knowledge. The following conclusions were derived: - the retention of all the radionuclides but chromium 51 decreased as soon as a low salinity appeared. Chromium (available as Cr 3+ ) precipitated quickly and strongly during fixation whatever the surfaces or the conditions: - as for the role of the clay type, illite showed a strong affinity for cesium 137; manganese 54 had a particular behaviour with montmorillonite that enhanced its precipitation into MnO 2 ; with cobalt, sodium and zinc, the percentages retained were always [fr

  13. A new understanding of inert gas narcosis

    International Nuclear Information System (INIS)

    Zhang Meng; Gao Yi; Fang Haiping

    2016-01-01

    Anesthetics are extremely important in modern surgery to greatly reduce the patient’s pain. The understanding of anesthesia at molecular level is the preliminary step for the application of anesthetics in clinic safely and effectively. Inert gases, with low chemical activity, have been found to cause anesthesia for centuries, but the mechanism is unclear yet. In this review, we first summarize the progress of theories about general anesthesia, especially for inert gas narcosis, and then propose a new hypothesis that the aggregated rather than the dispersed inert gas molecules are the key to trigger the narcosis to explain the steep dose-response relationship of anesthesia. (topical review)

  14. Characterization and morphology of solids suspended in rain water

    International Nuclear Information System (INIS)

    Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la

    2000-01-01

    This work presents the results obtained from the analysis of rain water in Mexico. The study treats over the characterization and morphology of the solids suspended in form of particles in the atmosphere. The solids suspended were obtained of the pluvial precipitations after these have been centrifuged. Subsequently of the separation, the particulate matter was analysed by Sem and X-ray dispersive energy

  15. INERT Atmosphere confinement operability test procedure

    International Nuclear Information System (INIS)

    RISENMAY, H.R.

    1999-01-01

    This Operability Test Procedure (OTP) provides instructions for testing operability of the Inert Atmosphere Confinement (IAC). The Inert Atmosphere Confinement was designed and built for opening cans of metal items that might have hydrided surfaces. Unreviewed Safety Question (USQ) PFP-97-005 addresses the discovery of suspected plutonium hydride forming on plutonium metal currently stored in the Plutonium Finishing Plant vaults. Plutonium hydride reacts quickly with air, liberating energy. The Inert Atmosphere Confinement was designed to prevent this sudden liberation of energy by opening the material in an inert argon atmosphere instead of the normal glovebox atmosphere. The IAC is located in glovebox HC-21A, room 230B of the 234-5Z Building at the Plutonium Finishing Plant (PFP) in the 200-West Area of the Hanford Site

  16. Optimizing the deposition of hydrogen evolution sites on suspended semiconductor particles using on-line photocatalytic reforming of aqueous methanol solutions.

    Science.gov (United States)

    Busser, G Wilma; Mei, Bastian; Muhler, Martin

    2012-11-01

    The deposition of hydrogen evolution sites on photocatalysts is a crucial step in the multistep process of synthesizing a catalyst that is active for overall photocatalytic water splitting. An alternative approach to conventional photodeposition was developed, applying the photocatalytic reforming of aqueous methanol solutions to deposit metal particles on semiconductor materials such as Ga₂O₃ and (Ga₀.₆ Zn₀.₄)(N₀.₆O₀.₄). The method allows optimizing the loading of the co-catalysts based on the stepwise addition of their precursors and the continuous online monitoring of the evolved hydrogen. Moreover, a synergetic effect between different co-catalysts can be directly established. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Illicit utilization of arsenic compounds in pyrotechnics? An analysis of the suspended particle emission during Vienna’s New Year fireworks

    International Nuclear Information System (INIS)

    Sterba, J.H.; Georg Steinhauser; Fritz Grass

    2013-01-01

    In the course of an investigation of an electrostatic precipitation technique as a sampling method for airborne dust particles, elevated concentrations of As were found in the data collected during New Years Eve celebrations in Vienna. The original study confirmed the applicability of the new sampling device as a useful sampling method, showing elevated values for the elements Na, Mg, Al, Si, S, K, Cu, As, Br, Rb, Sr, Sb, Te and Ba, all associated with the use of pyrotechnics. The measured values for As could not be explained as a impurity in some other substances used. Thus, several unburned pyrotechnic products were investigated to find the source of As in the dust collected. The results showed only one product with higher than expected As contents (1.4 μg g -1 ), leading to the assumption of intentional - but illicit - use of arsenic compounds in pyrotechnics as a colouring agent for the production of blue light. (author)

  18. Light absorption coefficients by phytoplankton pigments, suspended particles and colored dissolved organic matter in the Crimea coastal water (the Black sea) in June 2016

    Science.gov (United States)

    Moiseeva, N.; Churilova, T.; Efimova, T.; Krivenko, O.; Latushkin, A.

    2017-11-01

    Variability of the bio-optical properties of the Crimean coastal waters in June 2016 has been analyzed. The type of vertical distribution chlorophyll a concentration and phytoplankton light absorption coefficients and spectra shape differed between shallow and deeper water. In the deeper water seasonal stratification divided euphotic zone into layers with different environmental conditions. In the deeper part of the euphotic zone (below the thermocline) phytoplankton absorption spectra had local maximum at 550 nm, which was likely to be associated with high abundance of cyanobacteria (Synechococcus sps.) in the phytoplankton community. The concentration of chlorophyll a specific light absorption coefficient of phytoplankton decreased with depth (especially pronounced in the blue domain of the spectrum). In the shallow water the vertical distributions of all absorption properties were relatively homogeneous due to vertical water mixing. In the shallow water non-algal particles light absorption coefficient and its contribution to total particulate absorption were higher than those in the deeper water. The non-algal particles (NAP) and colored dissolved organic matter (CDOM) light absorption spectra were well described by an exponential function with a slope averaging 0.010 nm-1 (SD = 0.001 nm-1) and 0.022 nm-1 (SD = 0.0060 nm-1), correspondingly. The CDOM absorption at 440 nm and slope coefficient varied significantly across the investigated area, which was possibly associated with the terrestrial influences. The assessment of the contribution of phytoplankton, NAP and CDOM to total light absorption showed that CDOM dominated in the absorption at 440 nm.

  19. Inert gas transport in blood and tissues.

    Science.gov (United States)

    Baker, A Barry; Farmery, Andrew D

    2011-04-01

    This article establishes the basic mathematical models and the principles and assumptions used for inert gas transfer within body tissues-first, for a single compartment model and then for a multicompartment model. From these, and other more complex mathematical models, the transport of inert gases between lungs, blood, and other tissues is derived and compared to known experimental studies in both animals and humans. Some aspects of airway and lung transfer are particularly important to the uptake and elimination of inert gases, and these aspects of gas transport in tissues are briefly described. The most frequently used inert gases are those that are administered in anesthesia, and the specific issues relating to the uptake, transport, and elimination of these gases and vapors are dealt with in some detail showing how their transfer depends on various physical and chemical attributes, particularly their solubilities in blood and different tissues. Absorption characteristics of inert gases from within gas cavities or tissue bubbles are described, and the effects other inhaled gas mixtures have on the composition of these gas cavities are discussed. Very brief consideration is given to the effects of hyper- and hypobaric conditions on inert gas transport. © 2011 American Physiological Society. Compr Physiol 1:569-592, 2011.

  20. The Ages in a Self-Suspended Nanoparticle Liquid

    KAUST Repository

    Agarwal, Praveen; Qi, Haibo; Archer, Lynden A.

    2010-01-01

    Telomers ionically tethered to nanometer-sized particles yield self-suspended, nanoparticle-Iaden liquids with unusual dynamical features. By subjecting these suspensions to controlled, modest shear strains, we find that their flow behaviors

  1. Performances of continuous dryer with inert medium fluidized bed

    Directory of Open Access Journals (Sweden)

    Arsenijević Zorana Lj.

    2008-01-01

    Full Text Available A fluid bed dryer with inert particles represents a very attractive alternative to other drying technologies according to the main efficiency criteria, i.e. specific water evaporation rate, specific heat consumption and speci­fic air consumption. A high drying efficiency results from the large con­tact area and from the large temperature difference between the inlet and outlet air. A rapid mixing of the particles leads to nearly isothermal conditions throughout the bed. A fluid bed dryer with inert particles was used for drying of slurries. Experiments were performed in a cylindrical column 215 mm in diameter with glass spheres as inert particles. In this paper, results of drying experi­ments with slurries of Zineb fungicide, copper hydroxide, calcium carbo­nate and pure water used as the feed material are presented. In our fluidized bed we successfully dried a number of other materials such as: fungicides and pesticides (Ziram, Propineb, Mangozeb, copper oxy-chloride, copper oxy-sulphate, Bordeaux mixture, other inorganic compounds (calcium sulphate, cobalt carbonate, electrolytic copper, sodium chloride, and a complex compound (organo-bentonite. The effects of operating conditions on dryer throughput and product quality were investigated. Main performance criteria, i.e. specific water evaporation rate, specific heat consumption and specific air consumption, were quantified. Temperature profile along the bed was mapped, and nearly isothermal conditions were found due to thorough mixing of the particles. Analysis of drying and energy efficiencies as a function of inlet and outlet air temperature difference was performed for deeper insight in dryer behavior and for optimizing dryer design and operation from an energy point of view. A simple mathematical model based on an overall heat balance predicts the dryer performance quite well. The industrial prototype with fluid bed of 0.8 m in diameter and capacity 650 kg of evaporated moisture per

  2. Suspended graphene variable capacitor

    OpenAIRE

    AbdelGhany, M.; Mahvash, F.; Mukhopadhyay, M.; Favron, A.; Martel, R.; Siaj, M.; Szkopek, T.

    2016-01-01

    The tuning of electrical circuit resonance with a variable capacitor, or varactor, finds wide application with the most important being wireless telecommunication. We demonstrate an electromechanical graphene varactor, a variable capacitor wherein the capacitance is tuned by voltage controlled deflection of a dense array of suspended graphene membranes. The low flexural rigidity of graphene monolayers is exploited to achieve low actuation voltage in an ultra-thin structure. Large arrays compr...

  3. Suspended sediment concentration and particle size distribution ...

    Indian Academy of Sciences (India)

    prepared through direct digestion and finally analyzed by atomic absorption spectrophotometry (AAS). ... bivariate and multivariate regression models. Proposed models were then selected based on statistical criteria. The results .... 2.1 Field methods and sample collection. In order ... combination were also applied. Different ...

  4. temperature fluctuation inside inert atmosphere silos

    African Journals Online (AJOL)

    ... the two silos for twenty-eight (28) months of storage were recorded in order to monitor temperature fluctuation at different sections inside the inert atmosphere silos loaded with two varieties of wheat namely LACRIWHT-2 (Cettia) and LACRIWHT-4 (Atilla-Gan-Atilla) from Lake Chad Research Institute, Maiduguri, Nigeria.

  5. Inert carrier drying and coating process

    International Nuclear Information System (INIS)

    1980-01-01

    An inert carrier process is described for drying radioactive (particularly low level) waste material and for incorporating the dry material into a binder matrix from which the dried material will not be leached. Experimental details, and examples of the carrier and binder materials, are given. (U.K.)

  6. Mixed Inert scalar triplet dark matter, radiative neutrino masses and leptogenesis

    Directory of Open Access Journals (Sweden)

    Wen-Bin Lu

    2017-11-01

    Full Text Available The neutral component of an inert scalar multiplet with hypercharge can provide a stable dark matter particle when its real and imaginary parts have a splitting mass spectrum. Otherwise, a tree-level dark-matter-nucleon scattering mediated by the Z boson will be much above the experimental limit. In this paper we focus on a mixed inert scalar triplet dark matter scenario where a complex scalar triplet with hypercharge can mix with another real scalar triplet without hypercharge through their renormalizable coupling to the standard model Higgs doublet. We consider three specified cases that carry most of the relevant features of the full parameter space: (i the neutral component of the real triplet dominates the dark matter particle, (ii the neutral component of the complex triplet dominates the dark matter particle; and (iii the neutral components of the real and complex triplets equally constitute the dark matter particle. Subject to the dark matter relic abundance and direct detection constraint, we perform a systematic study on the allowed parameter space with particular emphasis on the interplay among triplet-doublet terms and gauge interactions. In the presence of these mixed inert scalar triplets, some heavy Dirac fermions composed of inert fermion doublets can be utilized to generate a tiny Majorana neutrino mass term at one-loop level and realize a successful leptogenesis for explaining the cosmic baryon asymmetry.

  7. Investigation of suspended sediment transport using ultrasonic techniques

    DEFF Research Database (Denmark)

    Bjørnø, Irina; Jensen, Leif Bjørnø

    1994-01-01

    The results of the initial experimental studies involving the scattering of ultrasonic signals from canonical and non-canonical shaped suspended particles with known elastical qualities are reported. These results have formed the basis for the development of a numerical model for ultrasound...... propagation through low-concentration suspensions of sand particles...

  8. Dynamic characteristics of stay cables with inerter dampers

    Science.gov (United States)

    Shi, Xiang; Zhu, Songye

    2018-06-01

    This study systematically investigates the dynamic characteristics of a stay cable with an inerter damper installed close to one end of a cable. The interest in applying inerter dampers to stay cables is partially inspired by the superior damping performance of negative stiffness dampers in the same application. A comprehensive parametric study on two major parameters, namely, inertance and damping coefficients, are conducted using analytical and numerical approaches. An inerter damper can be optimized for one vibration mode of a stay cable by generating identical wave numbers in two adjacent modes. An optimal design approach is proposed for inerter dampers installed on stay cables. The corresponding optimal inertance and damping coefficients are summarized for different damper locations and interested modes. Inerter dampers can offer better damping performance than conventional viscous dampers for the target mode of a stay cable that requires optimization. However, additional damping ratios in other vibration modes through inerter damper are relatively limited.

  9. Advanced On Board Inert Gas Generation System (OBBIGS), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Valcor Engineering Corporation proposes to develop an advanced On Board Inert Gas Generation System, OBIGGS, for aircraft fuel tank inerting to prevent hazardous...

  10. Portable spectrometer monitors inert gas shield in welding process

    Science.gov (United States)

    Grove, E. L.

    1967-01-01

    Portable spectrometer using photosensitive readouts, monitors the amount of oxygen and hydrogen in the inert gas shield of a tungsten-inert gas welding process. A fiber optic bundle transmits the light from the welding arc to the spectrometer.

  11. Inert gas handling in ion plating systems

    International Nuclear Information System (INIS)

    Goode, A.R.; Burden, M.St.J.

    1979-01-01

    The results of an investigation into the best methods for production and monitoring of the inert gas environment for ion plating systems are reported. Work carried out on Pirani gauges and high pressure ion gauges for the measurement of pressures in the ion plating region (1 - 50mtorr) and the use of furnaces for cleaning argon is outlined. A schematic of a gas handling system is shown and discussed. (UK)

  12. Reducing Actinide Production Using Inert Matrix Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Deinert, Mark [Colorado School of Mines, Golden, CO (United States)

    2017-08-23

    The environmental and geopolitical problems that surround nuclear power stem largely from the longlived transuranic isotopes of Am, Cm, Np and Pu that are contained in spent nuclear fuel. New methods for transmuting these elements into more benign forms are needed. Current research efforts focus largely on the development of fast burner reactors, because it has been shown that they could dramatically reduce the accumulation of transuranics. However, despite five decades of effort, fast reactors have yet to achieve industrial viability. A critical limitation to this, and other such strategies, is that they require a type of spent fuel reprocessing that can efficiently separate all of the transuranics from the fission products with which they are mixed. Unfortunately, the technology for doing this on an industrial scale is still in development. In this project, we explore a strategy for transmutation that can be deployed using existing, current generation reactors and reprocessing systems. We show that use of an inert matrix fuel to recycle transuranics in a conventional pressurized water reactor could reduce overall production of these materials by an amount that is similar to what is achievable using proposed fast reactor cycles. Furthermore, we show that these transuranic reductions can be achieved even if the fission products are carried into the inert matrix fuel along with the transuranics, bypassing the critical separations hurdle described above. The implications of these findings are significant, because they imply that inert matrix fuel could be made directly from the material streams produced by the commercially available PUREX process. Zirconium dioxide would be an ideal choice of inert matrix in this context because it is known to form a stable solid solution with both fission products and transuranics.

  13. Techniques for optimizing inerting in electron processors

    International Nuclear Information System (INIS)

    Rangwalla, I.J.; Korn, D.J.; Nablo, S.V.

    1993-01-01

    The design of an ''inert gas'' distribution system in an electron processor must satisfy a number of requirements. The first of these is the elimination or control of beam produced ozone and NO x which can be transported from the process zone by the product into the work area. Since the tolerable levels for O 3 in occupied areas around the processor are 3 in the beam heated process zone, or exhausting and dilution of the gas at the processor exit. The second requirement of the inerting system is to provide a suitable environment for completing efficient, free radical initiated addition polymerization. The competition between radical loss through de-excitation and that from O 2 quenching must be understood. This group has used gas chromatographic analysis of electron cured coatings to study the trade-offs of delivered dose, dose rate and O 2 concentrations in the process zone to determine the tolerable ranges of parameter excursions for production quality control purposes. These techniques are described for an ink coating system on paperboard, where a broad range of process parameters have been studied (D, D radical, O 2 ). It is then shown how the technique is used to optimize the use of higher purity (10-100 ppm O 2 ) nitrogen gas for inerting, in combination with lower purity (2-20,000 ppm O 2 ) non-cryogenically produced gas, as from a membrane or pressure swing adsorption generators. (author)

  14. 46 CFR 154.910 - Inert gas piping: Location.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Inert gas piping: Location. 154.910 Section 154.910 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... Atmospheric Control in Cargo Containment Systems § 154.910 Inert gas piping: Location. Inert gas piping must...

  15. Experimental study of an aircraft fuel tank inerting system

    Directory of Open Access Journals (Sweden)

    Cai Yan

    2015-04-01

    Full Text Available In this work, a simulated aircraft fuel tank inerting system has been successfully established based on a model tank. Experiments were conducted to investigate the influences of different operating parameters on the inerting effectiveness of the system, including flow rate of the inert gas (nitrogen-enriched air, inert gas concentration, fuel load of the tank and different inerting approaches. The experimental results show that under the same operating conditions, the time span of a complete inerting process decreased as the flow rate of inert gas was increased; the time span using the inert gas with 5% oxygen concentration was much longer than that using pure nitrogen; when the fuel tank was inerted using the ullage washing approach, the time span increased as the fuel load was decreased; the ullage washing approach showed the best inerting performance when the time span of a complete inerting process was the evaluation criterion, but when the decrease of dissolved oxygen concentration in the fuel was also considered to characterize the inerting effectiveness, the approach of ullage washing and fuel scrubbing at the same time was the most effective.

  16. Inert Reassessment Document for Gluconic Acid and Sodium Salt

    Science.gov (United States)

    Gluconic acid and D-gluconic acid are classified as List 3 inert ingredients, sodium gluconate is classified as a List 4B inert ingredient, and D-gluconic acid, sodium salt has not been categorized as to inert ingredient list classification status.

  17. Sedimentation of suspended solids in ultrasound field

    Directory of Open Access Journals (Sweden)

    Vikulina Vera

    2018-01-01

    Full Text Available Physical and chemical effects of aquatic environment that occur in an ultrasonic field change the sedimentation rate of coagulated suspension. This might only happen in case of cavitation of ultrasonic filed that causes a change of potentials of the medium. Research of the influence of ultrasonic vibrations on coagulation of suspended solids within water purification allows expanding their scope of implementation. The objective of the research is to estimate the effect of ultrasound on the sedimentation of the suspended solids, to determine of the efficiency of the process in relation to the dose of the coagulant, and to calculate the numerical values of the constants in the theoretical equation. The experiment condition was held in the water with the clay substances before the introduction of the coagulant. The method of magnetostriction ultrasonic generator was applied to receive ultrasonic vibration. Estimate of concentration of clay particles in water was performed using photometry. As a result of the research, the obtained data allow determining the increase in efficiency of suspended particles sedimentation related to the dose of coagulant, depending on time of ultrasonic treatment. The experiments confirmed the connection between the effect of sedimentation in the coagulation process, the coagulant dose and the time of scoring. Studies have shown that the increase in the duration of ultrasonic treatment causes a decrease of administered doses of coagulant.

  18. Magnetically suspended railway

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, C

    1977-07-28

    The invention concerns the emergency support of a magnetically suspended railway. On failure of the magnetic suspension/tracking system, the vehicles touch down on the rail configuration by means of emergency gliding elements like sliding shoes, skids, or the like. In doing this, the touch-down shock of the emergency gliding elements has to be limited to a force maximum as small as possible. According to the invention a spring-attenuator combination is used for this purpose, the spring characteristic being linear while the attenuator has a square-law characteristic for the compressing and a linear characteristic for the yielding motion. The force maximum thus achieved is exactly half the size of the physically smallest possible force maximum for an emergency gliding element springed without damping.

  19. Modeling, Testing, and Characteristic Analysis of a Planetary Flywheel Inerter

    Directory of Open Access Journals (Sweden)

    Zheng Ge

    2018-01-01

    Full Text Available We propose the planetary flywheel inerter, which is a new type of ball screw inerter. A planetary flywheel consists of several planetary gears mounted on a flywheel bracket. When the flywheel bracket is driven by a screw and rotating, each planetary gear meshing with an outer ring gear generates a compound motion composed of revolution and rotation. Theoretical analysis shows that the output force of the planetary flywheel inerter is proportional to the relative acceleration of one terminal of the inerter to the other. Optimizing the gear ratio of the planetary gears to the ring gear allows the planetary flywheel to be lighter than its traditional counterpart, without any loss on the inertance. According to the structure of the planetary flywheel inerter, nonlinear factors of the inerter are analyzed, and a nonlinear dynamical model of the inerter is established. Then the parameters in the model are identified and the accuracy of the model is validated by experiment. Theoretical analysis and experimental data show that the dynamical characteristics of a planetary flywheel inerter and those of a traditional flywheel inerter are basically the same. It is concluded that a planetary flywheel can completely replace a traditional flywheel, making the inerter lighter.

  20. Recoverying device for sodium vapor in inert gas

    Energy Technology Data Exchange (ETDEWEB)

    Nakagawa, Tamotsu; Nagashima, Ikuo

    1992-11-06

    A multi-pipe type heat exchanger for cooling an inert gas and a mist trap connected to the inert gas exit of the heat exchanger are disposed. A mist filter having bottomed pipes made of an inert gas-permeable sintered metal is disposed in the mist trap, and an inert gas discharge port is disposed at the upper side wall. With such a constitution, a high temperature inert gas containing sodium vapors can be cooled efficiently by the multi-pipe type heat exchanger capable of easy temperature control, thereby converting sodium vapors into mists, and the inert gas containing sodium mists can be flown into the mist trap. Sodium mists are collected by the mist filter and sodium mists flown down are discharged from the discharge port. With such procedures, a great amount of the inert gas containing sodium vapors can be processed continuously. (T.M.).

  1. Suspended particulate studies over the Madeira Abyssal Plain

    International Nuclear Information System (INIS)

    Simpson, W.R.

    1987-01-01

    Various aspects relating to suspended matter over the Madeira Abyssal Plain are discussed. Special attention is paid to the nepheloid layer including resuspension and transport processes; time variabilities in particle concentrations and fluxes; particle morphology, microbiology and chemical composition; phase association of metals. Also, tentative predictions of the behaviour of some radionuclides are made based on theory and data on rare earth elements. Instrumentation developed for the project is detailed - the deep water particle sampler. (author)

  2. Dry boxes and inert atmosphere techniques

    International Nuclear Information System (INIS)

    Bartak, D.E.

    1987-01-01

    Practitioners need to conduct experiments with molten salts in an inert atmosphere owing to the chemical reactivity of these media. Most fused salt solvent systems show reactivity to water and/or oxygen, which results in significant chemical changes in the properties of these solvents. Although several studies on the nature of an oxygen/oxide electrode in this melt have been reported, the reactions have not been fully understood because of apparent water contamination in many cases. Nitrate melt systems are also hygroscopic; for example, the LiNO 3 -KNO 3 eutectic (177 0 C) absorbs water to at least 0.2% by weight. The result is that the electrochemistry of heavier, electropositive metal ions has been significantly altered. In addition, trace amounts of water have been shown to significantly affect the oxygen-oxide redox chemistry in NaNO 3 -KNO 3 melts (250 0 C). The haloaluminates, which include AlCl 3 -NaCl (175 0 C), as well as AlCl 3 -organic salt binaries are particularly sensitive to the presence of both oxygen and moisture. Oxygen is a strong oxidant in the fused hydroxide systems with formation of superoxide ion from either oxide or water. This chapter describes general, inert atmosphere techniques which can be used by the molten salt experimentalist. Because of the limitations of volatility, vacuum manipulations are not considered. Rather, the use of glove boxes, glove bags, and inert bench-top techniques are discussed. The areas covered are: glove box and bag equipment, operation and maintenance of glove boxes and glove bags, and common operations conducted inside glove boxes

  3. Distribution and dynamics of radionuclides and stable elements in the coastal waters off Rokkasho Village, Japan, prior to the opening of a nuclear reprocessing facility. Part 1. Sedimentation flux of suspended particles and elimination of radionuclides and stable elements from seawater

    International Nuclear Information System (INIS)

    Kondo, K.; Kawabata, H.; Ueda, S.; Hasegawa, H.; Inaba, J.; Ohmomo, Y.; Mitamura, O.; Seike, Y.

    2004-01-01

    A nuclear fuel reprocessing facility is currently under construction in Rokkasho Village, Aomori, Japan. After completion and start-up, this facility will discharge radionuclides into the Pacific Ocean through an outlet pipe set on the seafloor offshore. For future assessments of the stability of these radionuclides in the environment, a sufficient understanding of the behavior of radionuclides in this ocean ecosystem before the start-up of the facility is necessary. To understand the processes by which radionuclides and various other types of elements are eliminated from seawater, we measured the sedimentation flux of suspended particles in the coastal waters off Rokkasho Village where the sea emissions pipes will be placed. (author)

  4. Inert atmosphere system for plutonium processing gloveboxes

    International Nuclear Information System (INIS)

    Bogard, C.F.; Calkins, K.W.; Rogers, R.F.

    1975-01-01

    Recent efforts to reduce fire hazards in plutonium processing operations are described. In such operations, the major environmental controls are developed through various kinds of glovebox systems. In evaluating the air-atmosphere glovebox systems, formerly in use at Rocky Flats and many other plants, a decision was made to convert to a recirculating ''inert'' atmosphere. The inert atmosphere consists of nitrogen, supplied from an on-site generating plant, diluting oxygen content to one to 5 percent by volume. Problems encountered during the change over included: determination of all factors influencing air leakage into the system, and reducing leakage to the practical minimum; meeting all fire and safety standards on the filter plenum and exhaust systems; provision for converting portions of the system to an air atmosphere to conduct maintenance work; inclusion of oxygen analyzers throughout the system to check gas quality and monitor for leaks; and the use of automatic controls to protect against a variety of potential malfunctions. The current objectives to reduce fire hazards have been met and additional safeguards were added. The systems are operating satisfactorily. (U.S.)

  5. Helium in inert matrix dispersion fuels

    International Nuclear Information System (INIS)

    Veen, A. van; Konings, R.J.M.; Fedorov, A.V.

    2003-01-01

    The behaviour of helium, an important decay product in the transmutation chains of actinides, in dispersion-type inert matrix fuels is discussed. A phenomenological description of its accumulation and release in CERCER and CERMET fuel is given. A summary of recent He-implantation studies with inert matrix metal oxides (ZrO 2 , MgAl 2 O 4 , MgO and Al 2 O 3 ) is presented. A general picture is that for high helium concentrations helium and vacancy defects form helium clusters which convert into over-pressurized bubbles. At elevated temperature helium is released from the bubbles. On some occasions thermal stable nano-cavities or nano-pores remain. On the basis of these results the consequences for helium induced swelling and helium storage in oxide matrices kept at 800-1000 deg. C will be discussed. In addition, results of He-implantation studies for metal matrices (W, Mo, Nb and V alloys) will be presented. Introduction of helium in metals at elevated temperatures leads to clustering of helium to bubbles. When operational temperatures are higher than 0.5 melting temperature, swelling and helium embrittlement might occur

  6. The Influence of Turbulent Coherent Structure on Suspended Sediment Transport

    Science.gov (United States)

    Huang, S. H.; Tsai, C.

    2017-12-01

    The anomalous diffusion of turbulent sedimentation has received more and more attention in recent years. With the advent of new instruments and technologies, researchers have found that sediment behavior may deviate from Fickian assumptions when particles are heavier. In particle-laden flow, bursting phenomena affects instantaneous local concentrations, and seems to carry suspended particles for a longer distance. Instead of the pure diffusion process in an analogy to Brownian motion, Levy flight which allows particles to move in response to bursting phenomena is suspected to be more suitable for describing particle movement in turbulence. And the fractional differential equation is a potential candidate to improve the concentration profile. However, stochastic modeling (the Differential Chapmen-Kolmogorov Equation) also provides an alternative mathematical framework to describe system transits between different states through diffusion/the jump processes. Within this framework, the stochastic particle tracking model linked with advection diffusion equation is a powerful tool to simulate particle locations in the flow field. By including the jump process to this model, a more comprehensive description for suspended sediment transport can be provided with a better physical insight. This study also shows the adaptability and expandability of the stochastic particle tracking model for suspended sediment transport modeling.

  7. On Suspended matter grain size in Baltic sea

    Science.gov (United States)

    Bubnova, Ekaterina; Sivkov, Vadim; Zubarevich, Victor

    2016-04-01

    Suspended matter grain size data were gathered during the 25th research vessel "Akademik Mstislav Keldysh" cruise (1991, September-October). Initial quantitative data were obtained with a use of the Coulter counter and subsequently modified into volume concentrations (mm3/l) for size intervals. More than 80 samples from 15 stations were analyzed (depth range 0-355 m). The main goal of research was to illustrate the spatial variability of suspended matter concentration and dispersion in Baltic Sea. The mutual feature of suspended matter grain size distribution is the logical rise of particle number along with descending of particle's size. Vertical variability of grain size distribution was defined by Baltic Sea hydrological structure, including upper mixed layer - from the surface to the thermocline - with 35 m thick, cold intermediate layer - from the thermocline to the halocline- and bottom layer, which lied under the halocline. Upper layer showed a rise in total suspended matter concentration (up to 0.6 mm3/l), while cold intermediate level consisted of far more clear water (up to 0.1 mm3/l). Such a difference is caused by the thermocline boarding role. Meanwhile, deep bottom water experienced surges in suspended matter concentration owing to the nepheloid layer presence and "liquid bottom" effect. Coastal waters appeared to have the highest amount of particles (up to 5.0 mm3/l). Suspended matter grain size distribution in the upper mixed layer revealed a peak of concentration at 7 μ, which can be due to autumn plankton bloom. Another feature in suspended matter grain size distribution appeared at the deep layer below halocline, where both O2 and H2S were observed and red/ox barrier is. The simultaneous presence of Fe and Mn (in solutions below red/ox barrier) and O2 leads to precipitation of oxyhydrates Fe and Mn and grain size distribution graph peaking at 4.5 μ.

  8. On the Benefits of Semi-Active Suspensions with Inerters

    Directory of Open Access Journals (Sweden)

    Xin-Jie Zhang

    2012-01-01

    Full Text Available Inerters have become a hot topic in recent years especially in vehicle, train, building suspension systems, etc. Eight different layouts of suspensions were analyzed with a quarter-car model in this paper. Dimensionless root mean square (RMS responses of the sprung mass vertical acceleration, the suspension travel, and the tire deflection are derived which were used to evaluate the performance of the quarter-car model. The behaviour of semi-active suspensions with inerters using Groundhook, Skyhook, and Hybrid control has been evaluated and compared to the performance of passive suspensions with inerters. Sensitivity analysis was applied to the development of a high performance semi-active suspension with an inerter. Numerical simulations indicate that a semi-active suspension with an inerter has much better performance than the passive suspension with an inerter, especially with the Hybrid control method, which has the best compromise between comfort and road holding quality.

  9. Purification of inert gas circuits of nuclear power facilities from tritium and hydrogen

    International Nuclear Information System (INIS)

    Eichler, R.

    1985-08-01

    Removing hydrogen and tritium from the inert primary coolant of a high temperature reactor is very important in regard to the process heat disposition. In this work a gas purification for a high temperature module reactor was laid out constructionally and researched technically. This system removes the contamination of the primary circuit with the aid of chemical getter beds of Cer alloy particles. (orig./PW) [de

  10. Analysis of the Danube river suspended load regime

    International Nuclear Information System (INIS)

    Lukac, M.

    2004-01-01

    In this presentation author deals with the analysis of the Danube river suspended load regime at the Slovak section of Danube. It is concluded and recommended: Suspended load transport at the Slovak section of Danube decreases in the downstream directions - annual averages: Utilize relation of the Water Research Institute in Medvedov, the relation of the Slovak Hydrometeorological Institute is probably slightly underestimated; Distribution of suspended load concentration in the cross-section is influenced mainly with local hydraulic and morphological conditions; Measured flow velocity in the range 0.6 - 2.65 m/sec -1 , influenced with water level slope; Silt particles the most numerous, less numerous sandy and clayey particles; Bratislava 3.54 mil. tonnes, Medvedov 2.22 mil. tonnes, and Komarno 1.96 mil. tonnes; Recommendation to measure actual volume of the Cunovo reservoir, in order to validate sediment transport balance; Recommendation to continue in a complex monitoring programme of sediment transport

  11. Catalytic Reactor for Inerting of Aircraft Fuel Tanks

    Science.gov (United States)

    1974-06-01

    Aluminum Panels After Triphase Corrosion Test 79 35 Inerting System Flows in Various Flight Modes 82 36 High Flow Reactor Parametric Data 84 37 System...AD/A-000 939 CATALYTIC REACTOR FOR INERTING OF AIRCRAFT FUEL TANKS George H. McDonald, et al AiResearch Manufacturing Company Prepared for: Air Force...190th Street 2b. GROUP Torrance, California .. REPORT TITLE CATALYTIC REACTOR FOR INERTING OF AIRCRAFT FUEL TANKS . OESCRIP TIVE NOTEs (Thpe of refpoft

  12. Observability of inert scalars at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Hashemi, Majid [Shiraz University, Physics Department, College of Sciences, Shiraz (Iran, Islamic Republic of); Najjari, Saereh [University of Warsaw, Faculty of Physics, Warsaw (Poland)

    2017-09-15

    In this work we investigate the observability of inert doublet model scalars at the LHC operating at the center of mass energy of 14 TeV. The signal production process is pp → AH{sup ±} → ZHW{sup ±}H leading to two different final states of l{sup +}l{sup -}HjjH and l{sup +}l{sup -}Hl{sup ±}νH based on the hadronic and leptonic decay channels of the W boson. All the relevant background processes are considered and an event selection is designed to distinguish the signal from the large Standard Model background. We found that signals of the selected search channels are well observable at the LHC with an integrated luminosity of 300 fb{sup -1}. (orig.)

  13. Inerting Aircraft Fuel Systems Using Exhaust Gases

    Science.gov (United States)

    Hehemann, David G.

    2002-01-01

    Our purpose in this proposal was to determine the feasibility of using carbon dioxide, possibly obtained from aircraft exhaust gases as a substance to inert the fuel contained in fuel tanks aboard aircraft. To do this, we decided to look at the effects carbon dioxide has upon commercial Jet-A aircraft fuel. In particular, we looked at the solubility of CO2 in Jet-A fuel, the pumpability of CO2-saturated Jet-A fuel, the flashpoint of Jet-A fuel under various mixtures of air and CO2, the static outgassing of CO2-Saturated Jet-A fuel and the dynamic outgassing of Jet-A fuel during pumping of Jet-A fuel.

  14. Seeded inert gas driven disk generator

    International Nuclear Information System (INIS)

    Joshi, N.K.; Venkatramani, N.; Rohatgi, V.K.

    1987-01-01

    This report outlines the present status of work being carried out in closed cycle MHD and disk generators. It gives the basic principles and discusses a proposal for setting up an experimental facility to study nonequilibrium plasmas using an inert gas driven disk generator. Disk geometry is a near ideal geometry for plasma studies since it has single or few pair electrodes combined with near perfect insulating walls. The proposed outlay of facility with components and subsystem is given. The facility may also be used to study the concept of fully ionized seed and to develop advanced diagnostic techniques. The absic equation describing the working parameters of such a system is also given in the Appendix. (author). 57 refs

  15. Inert doublet dark matter with an additional scalar singlet and 125 GeV Higgs boson

    Energy Technology Data Exchange (ETDEWEB)

    Dutta Banik, Amit; Majumdar, Debasish [Saha Institute of Nuclear Physics, Astroparticle Physics and Cosmology Division, Kolkata (India)

    2014-11-15

    In this work we consider a model for particle dark matter where an extra inert Higgs doublet and an additional scalar singlet is added to the Standard Model (SM) Lagrangian. The dark matter candidate is obtained from only the inert doublet. The stability of this one component dark matter is ensured by imposing a Z{sub 2} symmetry on this additional inert doublet. The additional singlet scalar has a vacuum expectation value (VEV) and mixes with the Standard Model Higgs doublet, resulting in two CP even scalars h{sub 1} and h{sub 2}. We treat one of these scalars, h{sub 1}, to be consistent with the SM Higgs-like boson of mass around 125 GeV reported by the LHC experiment. These two CP even scalars contribute to the annihilation cross section of this inert doublet dark matter, resulting in a larger dark matter mass region that satisfies the observed relic density. We also investigate the h{sub 1} → γγ and h{sub 1} → γ Z processes and compared these with LHC results. This is also used to constrain the dark matter parameter space in the present model. We find that the dark matter candidate in the mass region 60-80 GeV (m{sub 1} = 125 GeV, mass of h{sub 1}) satisfies the recent bound from LUX direct detection experiment. (orig.)

  16. Acoustic measuring techniques for suspended sediment

    Science.gov (United States)

    Gruber, P.; Felix, D.; Storti, G.; Lattuada, M.; Fleckenstein, P.; Deschwanden, F.

    2016-11-01

    Acoustic signals can be used in various ways for suspended sediment monitoring. One possibility which lends itself particularly well in the context of hydropower plants (HPPs), is to use installations for acoustic discharge measurement (ADM). Such installations already exist at waterways of many HPPs. Similar to certain turbidimeters, the attenuation of the forward scattered signal travelling through the water-sediment mixture is correlated with suspended sediment concentration (SSC). This correlation can be based on reference SSCs, e.g. from gravimetric analyses of bottle samples. Without the need of additional sensors and practically maintenance-free, this method is used successfully in the HPP Fieschertal to warn the HPP operator of high SSC to prevent excessive turbine abrasion. Acoustic methods and systems that allow for estimating both SSC and particle size distribution (PSD) are under development. The simultaneous determination of SSC and PSD is not possible using a single frequency. Therefore, multi-frequency approaches are investigated for generally scattered signals. When backscattered signals are used, a stronger frequency dependency can be exploited. However, the reliable simultaneous determination of particle size (and distribution) and concentration is still a major challenge due to a low signal-to-noise ratio and an ill- posed problem of estimating concentration and size from recorded signals. The optimal setup configuration (angles, frequencies) for such a system is not unique and further investigations are recommended.

  17. Method of producing hydrogen, and rendering a contaminated biomass inert

    Science.gov (United States)

    Bingham, Dennis N [Idaho Falls, ID; Klingler, Kerry M [Idaho Falls, ID; Wilding, Bruce M [Idaho Falls, ID

    2010-02-23

    A method for rendering a contaminated biomass inert includes providing a first composition, providing a second composition, reacting the first and second compositions together to form an alkaline hydroxide, providing a contaminated biomass feedstock and reacting the alkaline hydroxide with the contaminated biomass feedstock to render the contaminated biomass feedstock inert and further producing hydrogen gas, and a byproduct that includes the first composition.

  18. 46 CFR 154.908 - Inert gas generator: Location.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Inert gas generator: Location. 154.908 Section 154.908 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY... Atmospheric Control in Cargo Containment Systems § 154.908 Inert gas generator: Location. (a) Except as...

  19. Comfort-oriented vehicle suspension design with skyhook inerter configuration

    Science.gov (United States)

    Hu, Yinlong; Chen, Michael Z. Q.; Sun, Yonghui

    2017-09-01

    This paper is concerned with the comfort-oriented vehicle suspension design problem by using a skyhook inerter configuration. The rationale of the skyhook inerter is to use a grounded inerter to virtually increase the sprung mass of a vehicle, as it is analytically demonstrated that increasing the sprung mass can always improve the ride comfort performance. Semi-active means to realize the skyhook inerter configuration are investigated by using semi-active inerters. Three control laws, that is the on-off control, the anti-chatter on-off control, and the continuous control, are proposed for the semi-active inerter to approximate the skyhook inerter. Numerical simulations are performed to demonstrate the effectiveness and performances of these control laws. It is shown that the semi-active realizations of the skyhook inerter by using the proposed control laws can achieve over 10% improvement compared with the traditional strut, and similar performances are obtained for these control laws, with slight differences with respect to different static stiffnesses of the suspension system.

  20. Viking Helmet Corroles: Activating Inert Oxidometal Corroles.

    Science.gov (United States)

    Schweyen, Peter; Brandhorst, Kai; Hoffmann, Martin; Wolfram, Benedikt; Zaretzke, Marc-Kevin; Bröring, Martin

    2017-10-09

    Chemically inert oxidometal(V) corrols of molybdenum and rhenium undergo clean ligand-exchange reactions upon the action of SiCl 4 . The resulting dichlorido complexes show trigonal prismatic coordination of the metal ion with the chlorine atoms residing in a cis configuration, and were studied by optical and resonance spectroscopy as well as DFT calculations. In situ reactivity studies with carbon nucleophiles indicate high reactivity for chlorine replacement. Treatment with sodium cyclopentadienide paves the way to robust molybdenum corrolocene half-sandwich complexes. These organometallic compounds are the first corrole species that stabilize an air-stable and diamagnetic low spin d 2 -Mo IV center. Structural, spectroelectrochemical, and chemical investigations prove a reversible Mo IV /Mo V redox couple close to the Fc/Fc + potential for these systems. The high stability of the compounds in both redox states calls for future applications in catalysis and as redox switch. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Control characteristics of inert gas recovery plant

    International Nuclear Information System (INIS)

    Mikawa, Hiroji; Kato, Yomei; Kamiya, Kunio

    1980-01-01

    This paper presents a dynamic simulator and the control characteristics for a radioactive inert gas recovery plant which uses a cryogenic liquefying process. The simulator was developed to analyze the operational characteristics and is applicable to gas streams which contain nitrogen, argon, oxygen and krypton. The characteristics analysis of the pilot plant was performed after the accuracy of the simulator was checked using data obtained in fundamental experiments. The relationship between the reflux ratio and krypton concentration in the effluent gas was obtained. The decontamination factor is larger than 10 9 when the reflux ratio is more than 2. 0. The control characteristics of the plant were examined by changing its various parameters. These included the amount of gas to be treated, the heater power inside the evaporator and the liquid nitrogen level in the condenser. These characteristics agreed well with the values obtained in the pilot plant. The results show that the krypton concentration in the effluent gas increases when the liquid nitrogen level is decreased. However, in this case, the krypton concentration can be minimized by applying a feed forward control to the evaporator liquid level controller. (author)

  2. Suspended solids in liquid effluents

    International Nuclear Information System (INIS)

    McGrath, J.J.

    1988-06-01

    An international literature review and telephone mail survey was conducted with respect to technical and regulatory aspects of suspended solids in radioactive liquid wastes from nuclear power stations. Results of the survey are summarized and show that suspended solids are an important component of some waste streams. The data available, while limited, show these solids to be associated largely with corrosion products. The solids are highly variable in quantity, size and composition. Filtration is commonly applied for their removal from liquid effluents and is effective. Complex interactions with receiving waters can result in physical/chemical changes of released radionuclides and these phenomena have been seen as reason for not applying regulatory controls based on suspended solids content. 340 refs

  3. Bioactive and inert dental glass-ceramics.

    Science.gov (United States)

    Montazerian, Maziar; Zanotto, Edgar Dutra

    2017-02-01

    The global market for dental materials is predicted to exceed 10 billion dollars by 2020. The main drivers for this growth are easing the workflow of dentists and increasing the comfort of patients. Therefore, remarkable research projects have been conducted and are currently underway to develop improved or new dental materials with enhanced properties or that can be processed using advanced technologies, such as CAD/CAM or 3D printing. Among these materials, zirconia, glass or polymer-infiltrated ceramics, and glass-ceramics (GCs) are of great importance. Dental glass-ceramics are highly attractive because they are easy to process and have outstanding esthetics, translucency, low thermal conductivity, high strength, chemical durability, biocompatibility, wear resistance, and hardness similar to that of natural teeth, and, in certain cases, these materials are bioactive. In this review article, we divide dental GCs into the following two groups: restorative and bioactive. Most restorative dental glass-ceramics (RDGCs) are inert and biocompatible and are used in the restoration and reconstruction of teeth. Bioactive dental glass-ceramics (BDGCs) display bone-bonding ability and stimulate positive biological reactions at the material/tissue interface. BDGCs are suggested for dentin hypersensitivity treatment, implant coating, bone regeneration and periodontal therapy. Throughout this paper, we elaborate on the history, processing, properties and applications of RDGCs and BDGCs. We also report on selected papers that address promising types of dental glass-ceramics. Finally, we include trends and guidance on relevant open issues and research possibilities. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 619-639, 2017. © 2016 Wiley Periodicals, Inc.

  4. Preliminary Design Report Shippingport Spent Fuel Drying and Inerting System

    International Nuclear Information System (INIS)

    JEPPSON, D.W.

    2000-01-01

    A process description and system flow sheets have been prepared to support the design/build package for the Shippingport Spent Fuel Canister drying and inerting process skid. A process flow diagram was prepared to show the general steps to dry and inert the Shippingport fuel loaded into SSFCs for transport and dry storage. Flow sheets have been prepared to show the flows and conditions for the various steps of the drying and inerting process. Calculations and data supporting the development of the flow sheets are included

  5. Batch fabrication of nanotubes suspended between microelectrodes

    DEFF Research Database (Denmark)

    Mateiu, Ramona Valentina; Stöckli, T.; Knapp, H. F.

    2007-01-01

    be done with a simple lift-off process with standard photolithographic resist. An applied electric field is sustained between the microelectrodes during CVD to guide the nanotube growth. Comparison with simulations shows that the location and the orientation of the grown carbon nanotubes (CNT) correspond...... to the regions of maximum electric field, enabling accurate positioning of a nanotube by controlling the shape of the microelectrodes. The CNT bridges are deflected tens of nm when a DC voltage is applied between the nanotube and a gate microelectrode indicating that the clamping through the catalyst particles...... is not only mechanically stable but also electrical conducting. This method could be used to fabricate nanoelectromechanical systems based on suspended double clamped CNTs depending only on photolithography and standard Cleanroom processes....

  6. Self-Suspended Suspensions of Covalently Grafted Hairy Nanoparticles

    KAUST Repository

    Choudhury, Snehashis

    2015-03-17

    © 2015 American Chemical Society. Dispersions of small particles in liquids have been studied continuously for almost two centuries for their ability to simultaneously advance understanding of physical properties of fluids and their widespread use in applications. In both settings, the suspending (liquid) and suspended (solid) phases are normally distinct and uncoupled on long length and time scales. In this study, we report on the synthesis and physical properties of a novel family of covalently grafted nanoparticles that exist as self-suspended suspensions with high particle loadings. In such suspensions, we find that the grafted polymer chains exhibit unusual multiscale structural transitions and enhanced conformational stability on subnanometer and nanometer length scales. On mesoscopic length scales, the suspensions display exceptional homogeneity and colloidal stability. We attribute this feature to steric repulsions between grafted chains and the space-filling constraint on the tethered chains in the single-component self-suspended materials, which inhibits phase segregation. On macroscopic length scales, the suspensions exist as neat fluids that exhibit soft glassy rheology and, counterintuitively, enhanced elasticity with increasing temperature. This feature is discussed in terms of increased interpenetration of the grafted chains and jamming of the nanoparticles. (Chemical Presented).

  7. Studying Suspended Sediment Mechanism with Two-Phase PIV

    Science.gov (United States)

    Matinpour, H.; Atkinson, J. F.; Bennett, S. J.; Guala, M.

    2017-12-01

    Suspended sediment transport affects soil erosion, agriculture and water resources quality. Turbulent diffusion is the most primary force to maintain sediments in suspension. Although extensive previous literature have been studying the interactions between turbulent motion and suspended sediment, mechanism of sediments in suspension is still poorly understood. In this study, we investigate suspension of sediments as two distinct phases: one phase of sediments and another phase of fluid with turbulent motions. We designed and deployed a state-of-the-art two-phase PIV measurement technique to discriminate these two phases and acquire velocities of each phase separately and simultaneously. The technique that we have developed is employing a computer-vision based method, which enables us to discriminate sediment particles from fluid tracer particles based on two thresholds, dissimilar particle sizes and different particle intensities. Results indicate that fluid turbulence decreases in the presence of suspended sediments. Obtaining only sediment phase consecutive images enable us to compute fluctuation sediment concentration. This result enlightens understanding of complex interaction between the fluctuation velocities and the fluctuation of associated mass and compares turbulent viscosity with turbulent eddy diffusivity experimentally.

  8. An investigation of the microstructures and properties of metal inert ...

    Indian Academy of Sciences (India)

    Friction stir welding; metal inert gas welding; aluminum alloy 5083; ... (2008) have studied fatigue crack propagation behaviour of friction ..... Kumar K, Kailas SV 2008 The role of friction stir welding tool on material flow and weld formation,.

  9. TIG (Tungsten Inert Gas) welding; Le soudage TIG

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-09-15

    After having recalled the Tungsten Inert Gas process principle and the different alternative TIG processes, the author explains the advantages and limits of this process. The applications and recent developments are given. (O.M.)

  10. effects of metal inert gas welding parameters on some mechanical ...

    African Journals Online (AJOL)

    EFFECTS OF METAL INERT GAS WELDING PARAMETERS ON SOME MECHANICAL PROPERTIES OF AUSTENITIC STAINLESS STEEL IN ACIDIC ... Design Expert Software, Scanning Electron Microscopy (SEM), Rockwell Hardness Test, Monsanto Tensometer and Izod Impact Test were used to determine the ...

  11. Fog inerting criteria for hydrogen/air mixtures

    International Nuclear Information System (INIS)

    Tsai, S.S.; Liparulo, N.J.

    1982-01-01

    A distributed ignition system has been proposed to ignite hydrogen at low concentration in the ice condenser containment during severe accidents. The post-accident containment atmosphere could be misty due to fog generation from the break flow and condensation in the ice bed. Thus it is important to establish a fog inerting criterion for effective performance of the ignition system. This paper presents such a criterion that specifies the necessary fogging conditions, i.e., fog concentration and drop size, for inerting a hydrogen/air mixture. The criterion shows that the minimum fog inerting concentration varies with the square of the volume mean fog drop size. The present fog inerting criterion is shown to be in general agreement with the Factory Mutual test data

  12. А mathematical model study of suspended monorail

    OpenAIRE

    Viktor GUTAREVYCH

    2012-01-01

    The mathematical model of suspended monorail track with allowance for elastic strain which occurs during movement of the monorail carriage was developed. Standard forms for single span and double span of suspended monorail sections were established.

  13. А mathematical model study of suspended monorail

    Directory of Open Access Journals (Sweden)

    Viktor GUTAREVYCH

    2012-01-01

    Full Text Available The mathematical model of suspended monorail track with allowance for elastic strain which occurs during movement of the monorail carriage was developed. Standard forms for single span and double span of suspended monorail sections were established.

  14. Enhanced removal of radioactive particles by fluorocarbon surfactant solutions

    International Nuclear Information System (INIS)

    Kaiser, R.; Harling, O.K.

    1993-08-01

    The proposed research addressed the application of ESI's particle removal process to the non-destructive decontamination of nuclear equipment. The cleaning medium used in this process is a solution of a high molecular weight fluorocarbon surfactant in an inert perfluorinated liquid which results in enhanced particle removal. The perfluorinated liquids of interest, which are recycled in the process, are nontoxic, nonflammable, and environmentally compatible, and do not present a hazard to the ozone layer. The information obtained in the Phase 1 program indicated that the proposed ESI process is technically effective and economically attractive. The fluorocarbon surfactant solutions used as working media in the ESI process survived exposure of up to 10 Mrad doses of gamma rays, and are considered sufficiently radiation resistant for the proposed process. Ultrasonic cleaning in perfluorinated surfactant solutions was found to be an effective method of removing radioactive iron (Fe 59) oxide particles from contaminated test pieces. Radioactive particles suspended in the process liquids could be quantitatively removed by filtration through a 0.1 um membrane filter. Projected economics indicate a pre-tax pay back time of 1 month for a commercial scale system

  15. High concentration suspended sediment measurments using acontinuous fiber optic in-stream transmissometer

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Chris G.; Laycak, Danny T.; Hoppes, William; Tran,Nguyen T.; Shi, Frank G.

    2004-05-26

    Suspended sediment loads mobilized during high flow periods in rivers and streams are largely uncharacterized. In smaller and intermittent streams, a large storm may transport a majority of the annual sediment budget. Therefore monitoring techniques that can measure high suspended sediment concentrations at semi-continuous time intervals are needed. A Fiber optic In-stream Transmissometer (FIT) is presented for continuous measurement of high concentration suspended sediment in storm runoff. FIT performance and precision were demonstrated to be reasonably good for suspended sediment concentrations up to 10g/L. The FIT was compared to two commercially available turbidity devices and provided better precision and accuracy at both high and low concentrations. Both turbidity devices were unable to collect measurements at concentrations greater than 4 g/L. The FIT and turbidity measurements were sensitive to sediment particle size. Particle size dependence of transmittance and turbidity measurement poses the greatest problem for calibration to suspended sediment concentration. While the FIT was demonstrated to provide acceptable measurements of high suspended sediment concentrations, approaches to real-time suspended sediment detection need to address the particle size dependence in concentration measurements.

  16. The Prediction Methods for Potential Suspended Solids Clogging Types during Managed Aquifer Recharge

    Directory of Open Access Journals (Sweden)

    Xinqiang Du

    2014-04-01

    Full Text Available The implementation and development of managed aquifer recharge (MAR have been limited by the clogging attributed to physical, chemical, and biological reactions. In application field of MAR, physical clogging is usually the dominant type. Although numerous studies on the physical clogging mechanism during MAR are available, studies on the more detailed suspended clogging types and its prediction methods still remain few. In this study, a series of column experiments were inducted to show the process of suspended solids clogging process. The suspended solids clogging was divided into three types of surface clogging, inner clogging and mixed clogging based on the different clogging characteristics. Surface clogging indicates that the suspended solids are intercepted by the medium surface when suspended solids grain diameter is larger than pore diameter of infiltration medium. Inner clogging indicates that the suspended solids particles could transport through the infiltration medium. Mixed clogging refers to the comprehensive performance of surface clogging and inner clogging. Each suspended solids clogging type has the different clogging position, different changing laws of hydraulic conductivity and different deposition profile of suspended solids. Based on the experiment data, the ratio of effective medium pore diameter (Dp and median grain size of suspended solids (d50 was proposed as the judgment index for suspended solids clogging types. Surface clogging occurred while Dp/d50 was less than 5.5, inner clogging occurred while Dp/d50 was greater than 180, and mixed clogging occurred while Dp/d50 was between 5.5 and 180. In order to improve the judgment accuracy and applicability, Bayesian method, which considered more ratios of medium pore diameter (Dp and different level of grain diameter of suspended solids (di, were developed to predict the potential suspended solids types.

  17. Suspended Solids Profiler Shop Test Report

    International Nuclear Information System (INIS)

    STAEHR, T.W.

    2000-01-01

    The Suspended Solids Profiler (SSP) Instrument is planned to be installed in the AZ-101 tank to measure suspended solids concentrations during mixer pump testing. The SSP sensor uses a reflectance measurement principle to determine the suspended solids concentrations. The purpose of this test is to provide a documented means of verifying that the functional components of the SSP operate properly

  18. Water in the presence of inert Lennard-Jones obstacles

    Science.gov (United States)

    Kurtjak, Mario; Urbic, Tomaz

    2014-04-01

    Water confined by the presence of a 'sea' of inert obstacles was examined. In the article, freely mobile two-dimensional Mercedes-Benz (MB) water put to a disordered, but fixed, matrix of Lennard-Jones disks was studied by the Monte Carlo computer simulations. For the MB water molecules in the matrix of Lennard-Jones disks, we explored the structures, hydrogen-bond-network formation and thermodynamics as a function of temperature and size and density of matrix particles. We found that the structure of model water is perturbed by the presence of the obstacles. Density of confined water, which was in equilibrium with the bulk water, was smaller than the density of the bulk water and the temperature dependence of the density of absorbed water did not show the density anomaly in the studied temperature range. The behaviour observed as a consequence of confinement is similar to that of increasing temperature, which can for a matrix lead to a process similar to capillary evaporation. At the same occupancy of space, smaller matrix molecules cause higher destruction effect on the absorbed water molecules than the bigger ones. We have also tested the hypothesis that at low matrix densities the obstacles induce an increased ordering and 'hydrogen bonding' of the MB model molecules, relative to pure fluid, while at high densities the obstacles reduce MB water structuring, as they prevent the fluid to form good 'hydrogen-bonding' networks. However, for the size of matrix molecules similar to that of water, we did not observe this effect.

  19. Pulmonary distribution of [sup 99m]Tc-technegas; A comparative study of radioactive inert gases

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Kenji; Shimada, Takao; Mori, Yutaka; Goto, Eisuke; Hirasawa, Yukinori [Jikei Univ., Tokyo (Japan). School of Medicine; Tominaga, Shigeru

    1992-10-01

    Technetium 99m-technegas ([sup 99m]Tc-gas), which consists of fine particles, is produced in carbon crucibles burned at 2500degC. In this study, the particle size of [sup 99m]Tc-gas was measured and the pulmonary distribution of [sup 99m]Tc-gas was assessed in 28 patients with various pulmonary diseases. Most particles were 5[approx]30 nm in diameter as determined by electron microscopy. In a clinical study, about 37 MBq of [sup 99m]Tc-gas was inhaled three times during deep breathing in a sitting position. In a comparative study with radioactive inert gases ([sup 133]Xe, [sup 81m]Kr), [sup 99m]Tc-gas showed a similar distribution to the inert gas in most patients, although some with obstructive disease showed hot spots in the lung fields. In patients with severe obstructive change, marked deposits of [sup 99m]Tc-gas was noted in the central airways, but [sup 99m]Tc-gas penetrated to the peripheral lung field. This result suggests that [sup 99m]Tc-gas can be used to evaluate ventilatory function even in patients with chronic obstructive pulmonary diseases. (author).

  20. Suspended matter and heavy metal content of the Elbe Estuary

    International Nuclear Information System (INIS)

    Vollbrecht, K.

    1980-01-01

    (1) In the River Elbe estuary there is a turbidity zone which is closely bound to the region of brackish waters. Its suspended matter content changes strongly with the tidal rhythm. Suspended matter and river bed sediments influence each other by exchanging their particles. Owing to that mechanism, the heavy metal ions bound or taken up by the suspended matter (sorption) enter the sediments. To obtain an estimation of the estuary's ability to cope with ( self purify ) a strong burden of industrial wastes, it is neccessary to take into consideration the absorbing capacity of both the mean suspension load and the sediments. (2) The concentration of nearly all heavy metal ions investigated in the suspension load decreases remarkably at the very beginning of the turbid zone already, in the Hamburg region. It indicates that the binding process are going on very rapidly and that the metal ion absorbing capacity of the Elbe estuary still requires only the first few miles of this self purification system. The results gained indicate that the suspended matter in Hamburg waters could bind or take up more heavy metal ions than are discharged into this area. (3) The concentration of most ions bound to the suspension material correlates very well with the grain size distribution of the (anorganic) particles. The concentration values decrease along the estuary and lead to a continuous transition to the values of the open sea. Cu, Ni and Cd appear to be captured preferably by organic suspended matter. This behaviour, however, is solely restricted to the turbid zone. In the open sea, after oxidation of the binding organic material, Cu and Ni correspond to the anorganic grain size distribution. (orig./HP) [de

  1. Distribution and transportation of suspended sediment

    International Nuclear Information System (INIS)

    Schubel, J.R.

    1975-01-01

    A number of studies of the distribution and character of suspended matter in the waters of the Atlantic shelf have documented the variations in the concentration of total suspended matter in both time and space. Very little is known, however, about the ultimate sources of inorganic suspended matter, and even less is known about the routes and rates of suspended sediment transport in shelf waters. Suspended particulate matter constitutes a potential vehicle for the transfer of energy-associated contaminants, radionuclides and oil, back to the coast and therefore to man. The concentrations of total suspended matter in shelf waters are typically so low, however, that the mechanism is ineffective. Studies of suspended particulate matter have a high scientific priority, but in this investigator's opinion the state of knowledge is adequate for preparation of the environmental impact statements that would be required for siting of offshore nuclear power plants and for oil drilling on the Atlantic Continental Shelf

  2. The release code package REVOLS/RENONS for fission product release from a liquid sodium pool into an inert gas atmosphere

    International Nuclear Information System (INIS)

    Starflinger, J.; Scholtyssek, W.; Unger, H.

    1994-12-01

    For aerosol source term considerations in the field of nuclear safety, the investigation of the release of volatile and non-volatile species from liquid surfaces into a gas atmosphere is important. In case of a hypothetical liquid metal fast breeder reactor accident with tank failure, primary coolant sodium with suspended or solved fuel particles and fission products may be released into the containment. The computer code package REVOLS/RENONS, based on a theoretical mechanistic model with a modular structure, has been developed for the prediction of sodium release as well as volatile and non-volatile radionuclide release from a liquid pool surface into the inert gas atmosphere of the inner containment. Hereby the release of sodium and volatile fission products, like cesium and sodium iodide, is calculated using a theoretical model in a mass transfer coefficient formulation. This model has been transposed into the code version REVOLS.MOD1.1, which is discussed here. It enables parameter analysis under highly variable user-defined boundary conditions. Whereas the evaporative release of the volatile components is governed by diffusive and convective transport processes, the release of the non-volatile ones may be governed by mechanical processes which lead to droplet entrainment from the wavy pool surface under conditions of natural or forced convection into the atmosphere. The mechanistic model calculates the liquid entrainment rate of the non-volatile species, like the fission product strontium oxide and the fuel (uranium dioxide) from a liquid pool surface into a parallel gas flow. The mechanistic model has been transposed into the computer code package REVOLS/RENONS, which is discussed here. Hereby the module REVOLS (RElease of VOLatile Species) calculates the evaporative release of the volatile species, while the module RENONS (RElease of NON-Volatile Species) computes the entrainment release of the non-volatile radionuclides. (orig./HP) [de

  3. Characterization and morphology of solids suspended in rain water; Caracterizacion y morfologia de solidos suspendidos en agua de lluvia

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Mexico D.F. (Mexico)

    2000-07-01

    This work presents the results obtained from the analysis of rain water in Mexico. The study treats over the characterization and morphology of the solids suspended in form of particles in the atmosphere. The solids suspended were obtained of the pluvial precipitations after these have been centrifuged. Subsequently of the separation, the particulate matter was analysed by Sem and X-ray dispersive energy.

  4. Vertical transport of suspended particulate trace elements in the North Atlantic Ocean

    International Nuclear Information System (INIS)

    Kuss, J.; Kremling, K.; Scholten, J.

    1999-01-01

    Suspended marine particles play a key role in the exchange processes between rapidly sinking particles and seawater because of their large surface area and long residence times. They are involved in the transport processes of rapidly sinking particles (∼ 100 m/day) through aggregation and disaggregation. This mechanism results in a net downward transport of suspended particulate trace elements (TE). To provide more information to these processes TE in suspended particulate material (SPM) have been measured on three cruises from 1995 to 1997 along 20 deg. W using a large volume in situ filtration between 25 m and 4150 m depth in addition to particle flux measurements with sediment traps. These studies were performed under the framework of German JGOFS

  5. Adaption of the suspension behavior of suspended matter in natural water

    International Nuclear Information System (INIS)

    Hattenbach, K.; Schreier, H.H.; Zimmermann, H.U.

    1980-01-01

    The particle size distribution of an artificial tracer is adapted to that of suspended matter in natural water. Therefore the material of a tracer was divided into fractions and afterwards mixed according to computed proportions. The determination of particle size distribution was carried out using a sedimentation balance. For calculation of the distribution curve a special mathematical function was assumed. (orig.) [de

  6. Neutralino dark matter with inert higgsinos and singlinos

    International Nuclear Information System (INIS)

    Hall, Jonathan P.; King, Stephen F.

    2009-01-01

    We discuss neutralino dark matter arising from supersymmetric models with extra inert Higgsinos and singlinos, where inert means that their scalar partners do not get vacuum expectation values. As an example, we consider the extended neutralino sector of the E 6 SSM, which predicts three families of Higgs doublet pairs, plus three singlets, plus a Z', together with their fermionic superpartners. We show that the two families of inert doublet Higgsinos and singlinos predicted by this model provide an almost decoupled neutralino sector with a naturally light LSP which can account for the cold dark matter relic abundance independently of the rest of the model, providing that the ratio of the two usual Higgs doublets satisfies tan β < 2.

  7. Collider and dark matter searches in the inert doublet model from Peccei-Quinn symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Alexandre [Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo,Diadema-SP, 09972-270 (Brazil); Camargo, Daniel A.; Dias, Alex G. [Universidade Federal do ABC, Centro de Ciências Naturais e Humanas,09210-580, Santo André-SP (Brazil); Longas, Robinson [Instituto de Física, Universidad de Antioquia,Calle 70 No. 52-21, Medellín (Colombia); Nishi, Celso C. [Universidade Federal do ABC, Centro de Matemática, Computação e Cognição Naturais,09210-580, Santo André-SP (Brazil); Queiroz, Farinaldo S. [Max-Planck-Institut fur Kernphysik,Saupfercheckweg 1, 69117 Heidelberg (Germany)

    2016-10-04

    Weakly Interacting Massive Particles (WIMPs) and axions are arguably the most compelling dark matter candidates in the literature. Could they coexist as dark matter particles? More importantly, can they be incorporated in a well motivated framework in agreement with experimental data? In this work, we show that this two component dark matter can be realized in the Inert Doublet Model in an elegant and natural manner by virtue of the spontaneous breaking of a Peccei-Quinn U(1){sub PQ} symmetry into a residual ℤ{sub 2} symmetry. The WIMP stability is guaranteed by the ℤ{sub 2} symmetry and a new dark matter component, the axion, arises. There are two interesting outcomes: (i) vector-like quarks needed to implement the Peccei-Quinn symmetry in the model may act as a portal between the dark sector and the SM fields with a supersymmetry-type phenomenology at colliders; (ii) two-component Inert Doublet Model re-opens the phenomenologically interesting 100–500 GeV mass region. We show that the model can successfully realize a two component dark matter framework and at the same time avoid low and high energy physics constraints such as monojet and dijet plus missing energy, as well as indirect and direct dark matter detection bounds.

  8. Ignition of a reactive solid by an inert hot spot

    OpenAIRE

    Liñán Martínez, Amable; Kindelan Gómez, Manuel

    1981-01-01

    A theoretical analysis is presented for the description of the ignition of a reactive media by inert hot bodies of finite size, when the activation energy of the reaction is large. The analysis leads to closed-form relations for the minimum "critical" size of the hot spot resulting in ignition and for the ignition time by hot spots of supercritical size. The analysis is carried out, first, for inert spots with heat conductivities and diff usivities of the order of those of the reactive media,...

  9. INERT-MATRIX FUEL: ACTINIDE ''BURNING'' AND DIRECT DISPOSAL

    International Nuclear Information System (INIS)

    Rodney C. Ewing; Lumin Wang

    2002-01-01

    Excess actinides result from the dismantlement of nuclear weapons (Pu) and the reprocessing of commercial spent nuclear fuel (mainly 241 Am, 244 Cm and 237 Np). In Europe, Canada and Japan studies have determined much improved efficiencies for burnup of actinides using inert-matrix fuels. This innovative approach also considers the properties of the inert-matrix fuel as a nuclear waste form for direct disposal after one-cycle of burn-up. Direct disposal can considerably reduce cost, processing requirements, and radiation exposure to workers

  10. Suspended dust in Norwegian cities

    International Nuclear Information System (INIS)

    2001-01-01

    According to calculations, at least 80 000 people in Oslo and 8 000 in Trondheim were annoyed by too much suspended dust in 2000. The dust concentration is greatest in the spring, presumably because dust is swirling up from melting snow and ice on the streets. Car traffic is the main source of the dust, except for some of the most highly exposed regions where wood-firing from old stoves contributes up to 70 percent of the dust. National targets for air quality include suspended dust, nitrogen dioxide, sulphur dioxide and benzene. Calculations show that nitrogen dioxide emissions exceeding the limit affected 4 000 people in Oslo and 1 000 people in Trondheim. The sulphur dioxide emissions in the major cities did non exceed the national quality limit; they did exceed the limit in some of the smaller industrial centres. In Trondheim, measurements show that the national limit for benzene was exceeded. Most of the emission of nitrogen dioxide comes from the road traffic. Local air pollution at times causes considerable health- and well-being problems in the larger cities and industrial centres, where a great part of the population may be at risk of early death, infection of the respiratory passage, heart- and lung diseases and cancer

  11. Retention and Migration of Fine Organic Particles within an Agricultural Stream: Toenepi, Waikato, New Zealand

    Science.gov (United States)

    Drummond, J. D.; Davies-Colley, R.; Stott, R.; Sukias, J.; Nagels, J.; Sharp, A.; Packman, A. I.

    2013-12-01

    Fine organic particle dynamics are important to stream biogeochemistry, ecology, and transport of contaminant microbes. These particles migrate downstream through a series of deposition and resuspension events, which results in a wide range of residence times. This retention influences biogeochemical processing and in-stream stores of contaminant microbes that may mobilize during flood events and present a hazard to downstream uses such as water supplies and recreation. We are conducting studies to gain insights into organic particle dynamics in streams, with a campaign of experiments and modeling. The results should improve understanding of nutrient (C, N, P) spiraling and fine sediment movement in streams, and have particular application to microbial hazards. We directly measure microbial transport by including the indicator organism, E. coli, as a tracer, which is compared to a fluorescent inert particle tracer and conservative solute to gain insight on both microbial ecology and waterborne disease transmission. We developed a stochastic model to describe the transport and retention of fine suspended particles in rivers, including advective delivery of particles to the streambed, transport through porewaters, and reversible filtration within the streambed. Because fine particles are only episodically transported in streams, with intervening periods at rest in the bed, this transport process violates conventional advection-dispersion assumptions. Instead we adopt a stochastic mobile-immobile model formulation to describe fine particle transport. We apply this model to measurements of particle transport from multiple tracer experiments in an agricultural stream in the Waikato dairy region of New Zealand, and use the model to improve interpretation of baseflow particle dynamics. Our results show the importance of the benthic and hyporheic regions and in-stream vegetation as a reservoir for fine organic particles in streams.

  12. Synthesis of Fe Nanoparticles Functionalized with Oleic Acid Synthesized by Inert Gas Condensation

    Directory of Open Access Journals (Sweden)

    L. G. Silva

    2014-01-01

    Full Text Available In this work, we study the synthesis of monodispersed Fe nanoparticles (Fe-NPs in situ functionalized with oleic acid. The nanoparticles were self-assembled by inert gas condensation (IGC technique by using magnetron-sputtering process. Structural characterization of Fe-NPs was performed by transmission electron microscopy (TEM. Particle size control was carried out through the following parameters: (i condensation zone length, (ii magnetron power, and (iii gas flow (Ar and He. Typically the nanoparticles generated by IGC showed diameters which ranged from ~0.7 to 20 nm. Mass spectroscopy of Fe-NPs in the deposition system allowed the study of in situ nanoparticle formation, through a quadrupole mass filter (QMF that one can use together with a mass filter. When the deposition system works without quadrupole mass filter, the particle diameter distribution is around +/−20%. When the quadrupole is in line, then the distribution can be reduced to around +/−2%.

  13. Conformally invariant Inert Higgs doublet model: an unified model for Inflation and Dark matter

    International Nuclear Information System (INIS)

    Das, Moumita; Mohanty, Subhendra

    2012-01-01

    Motivation of our present study is the searching for an unified model which can describe both the inflation as well as dark matter. From particle physics point of view, Higgs can be the most interesting candidate for the scalar field inflation. Conformal coupling of the inflaton with the gravity can generate the density perturbation and we use this idea in a realistic inert Higgs doublet model. We study the loop corrections of this conformally coupled system and in present era there is electroweak symmetry breaking to provide the mass of the particles. Study of the mass spectrum in present era reveals the scalar dark matter with mass 33.7 GeV and lightest Higgs at 125.6 GeV.

  14. Model identification methodology for fluid-based inerters

    Science.gov (United States)

    Liu, Xiaofu; Jiang, Jason Zheng; Titurus, Branislav; Harrison, Andrew

    2018-06-01

    Inerter is the mechanical dual of the capacitor via the force-current analogy. It has the property that the force across the terminals is proportional to their relative acceleration. Compared with flywheel-based inerters, fluid-based forms have advantages of improved durability, inherent damping and simplicity of design. In order to improve the understanding of the physical behaviour of this fluid-based device, especially caused by the hydraulic resistance and inertial effects in the external tube, this work proposes a comprehensive model identification methodology. Firstly, a modelling procedure is established, which allows the topological arrangement of the mechanical networks to be obtained by mapping the damping, inertance and stiffness effects directly to their respective hydraulic counterparts. Secondly, an experimental sequence is followed, which separates the identification of friction, stiffness and various damping effects. Furthermore, an experimental set-up is introduced, where two pressure gauges are used to accurately measure the pressure drop across the external tube. The theoretical models with improved confidence are obtained using the proposed methodology for a helical-tube fluid inerter prototype. The sources of remaining discrepancies are further analysed.

  15. An investigation of the microstructures and properties of metal inert ...

    Indian Academy of Sciences (India)

    Abstract. Two different types of welds, Metal Inert Gas (MIG) and Friction Stir. Welding (FSW), have been used to weld aluminum alloy 5083. The microstructure of the welds, including the nugget zone and heat affected zone, has been compared in these two methods using optical microscopy. The mechanical properties of ...

  16. MECHANISM OF PARTICLE SUSPENSION OVER A SAND WAVE

    OpenAIRE

    芦田, 和男; 藤田, 正治; 向井, 健

    1986-01-01

    The characteristics of flow vary with space over sand waves. It is important to consider thisnouniformity in the modeling of motions of suspended particles, but few methods for calculationof suspended load have been proposed by consideration of this efects. In this paper mean velocityand turbulent strength of flow are discussed experimentally over a two-dimensinal sand wave andthe motion of suspended particle are formulated using these results and authors' theory on modelof particle motion ov...

  17. Viscous bursting of suspended films

    Science.gov (United States)

    Debrégeas, G.; Martin, P.; Brochard-Wyart, F.

    1995-11-01

    Soap films break up by an inertial process. We present here the first observations on freely suspended films of long-chain polymers, where viscous effects are dominant and no surfactant is present. A hole is nucleated at time 0 and grows up to a radius R(t) at time t. A surprising feature is that the liquid from the hole is not collected into a rim (as it is in soap films): The liquid spreads out without any significant change of the film thickness. The radius R(t) grows exponentially with time, R~exp(t/τ) [while in soap films R(t) is linear]. The rise time τ~ηe/2γ where η is viscosity, e is thickness (in the micron range), and γ is surface tension. A simple model is developed to explain this growth law.

  18. Inert materials for the GFR fuel. Characterizations, chemical interactions and irradiation damage

    International Nuclear Information System (INIS)

    Audubert, Fabienne; Carlot, Gaoelle; Lechelle, Jacques; David, Laurent; Gomes, Severine

    2005-01-01

    In the framework of an extensive R and D Program on GFR fuel, studies on inert materials have been performed at the French Atomic Energy Commission (CEA). The inert materials would be associated with the fuel with the aim of featuring an efficient barrier to radiotoxic species with regard to the cooling circuit of the reactor. Potential matrices identified for dispersion fuels or particles fuels are SiC, TiN, ZrN, ZrC, TiC. Physical microstructural and thermal properties have been determined in order to evaluate elaboration process effects. The evolution under irradiation of thermal properties (such as conductivity, diffusivity) of the materials has been studied using heavy ions to simulate fission product irradiation. After irradiation, scanning thermal microscopy is used to investigate the thermal degradation of the materials. Thermal conductivity variations were obtained on TiC irradiated with krypton ion at an energy of 86 MeV and a fluence of 5.10 15 ions.cm -2 . They are quantified at 19 W.m -1 .K -1 . On other materials such as SiC, ZrC, TiN, no thermal conductivity contrast was shown. Reactivity between the inert matrix (SiC or TiN) and the fuel (U, Pu)N have been evaluated on powders and on ceramic samples in contact by a thermal treatment under several atmospheres. It was shown that SiC reacts with (U, Pu)N in various atmospheres making secondary phases as PuSi 2 , USi 2 , U 20 Si 16 C 3 . TiN behaviour seems to be better: the only reactivity which may take place would be a variation of the nitrogen stoichiometry in TiN and (U, Pu)N at the interface. (author)

  19. Suspended sediment drift and dispersion at Hibernia

    International Nuclear Information System (INIS)

    Tedford, T.; Drozdowski, A.; Hannah, C.G.

    2003-01-01

    Surface water waves and near-bottom currents around the Hibernia oil production platform on the Grand Banks of Newfoundland were examined to determine how the different seasons affect changes in wave magnitude and directions of water currents. Wave observations revealed a strong correlation with seasons, with the larger waves occurring in fall and early winter. There was no obvious seasonality in the size or direction of currents. The benthic boundary layer transport (BBLT) model was used to predict the drift and dispersion pathways of suspended drilling muds discharged from the Hibernia platform. The 2-year study from March 1998 to May 2000 involved 5-day BBLT model simulations covering the complete period of current meter deployment. The study focused on the sensitivity of the drift and dispersion to variability in the physical environment and uncertainty in the bottom stress calculation and particle settling velocity. The BBLT model incorporates a stress dependent particle settling velocity that includes the main features of the flocculations of drill mud fines under marine conditions. The study provides a better understanding of how drill mud concentration levels can change with variations in waves, currents, and bottom stress. It was determined that drift is generally oriented along the northwest/southeast axis, with a typical magnitude of 0.8 cm/sec for the fast settling velocity and 3.1 cm/sec for the slow settling velocity. It was concluded that near-surface or mid-depth discharges of drilling mud in the summer may not reach the sea floor. 17 refs., 13 tabs., 36 figs

  20. Intermodal resonance of vibrating suspended cables

    NARCIS (Netherlands)

    Rienstra, S.W.

    2010-01-01

    The weakly nonlinear free vibrations of a single suspended cable, or a coupled system of suspended cables, may be classified as gravity modes (no tension variations to leading order) and elasto-gravity modes (tension and vertical displacement equally important). It was found earlier [12] that the

  1. Particle transport in porous media

    Science.gov (United States)

    Corapcioglu, M. Yavuz; Hunt, James R.

    The migration and capture of particles (such as colloidal materials and microorganisms) through porous media occur in fields as diversified as water and wastewater treatment, well drilling, and various liquid-solid separation processes. In liquid waste disposal projects, suspended solids can cause the injection well to become clogged, and groundwater quality can be endangered by suspended clay and silt particles because of migration to the formation adjacent to the well bore. In addition to reducing the permeability of the soil, mobile particles can carry groundwater contaminants adsorbed onto their surfaces. Furthermore, as in the case of contamination from septic tanks, the particles themselves may be pathogens, i.e., bacteria and viruses.

  2. Characterization of Tungsten Inert Gas (TIG) Welding Fume Generated by Apprentice Welders.

    Science.gov (United States)

    Graczyk, Halshka; Lewinski, Nastassja; Zhao, Jiayuan; Concha-Lozano, Nicolas; Riediker, Michael

    2016-03-01

    Tungsten inert gas welding (TIG) represents one of the most widely used metal joining processes in industry. Its propensity to generate a greater portion of welding fume particles at the nanoscale poses a potential occupational health hazard for workers. However, current literature lacks comprehensive characterization of TIG welding fume particles. Even less is known about welding fumes generated by welding apprentices with little experience in welding. We characterized TIG welding fume generated by apprentice welders (N = 20) in a ventilated exposure cabin. Exposure assessment was conducted for each apprentice welder at the breathing zone (BZ) inside of the welding helmet and at a near-field (NF) location, 60cm away from the welding task. We characterized particulate matter (PM4), particle number concentration and particle size, particle morphology, chemical composition, reactive oxygen species (ROS) production potential, and gaseous components. The mean particle number concentration at the BZ was 1.69E+06 particles cm(-3), with a mean geometric mean diameter of 45nm. On average across all subjects, 92% of the particle counts at the BZ were below 100nm. We observed elevated concentrations of tungsten, which was most likely due to electrode consumption. Mean ROS production potential of TIG welding fumes at the BZ exceeded average concentrations previously found in traffic-polluted air. Furthermore, ROS production potential was significantly higher for apprentices that burned their metal during their welding task. We recommend that future exposure assessments take into consideration welding performance as a potential exposure modifier for apprentice welders or welders with minimal training. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  3. Characterization of Tungsten Inert Gas (TIG) Welding Fume Generated by Apprentice Welders

    Science.gov (United States)

    Graczyk, Halshka; Lewinski, Nastassja; Zhao, Jiayuan; Concha-Lozano, Nicolas; Riediker, Michael

    2016-01-01

    Tungsten inert gas welding (TIG) represents one of the most widely used metal joining processes in industry. Its propensity to generate a greater portion of welding fume particles at the nanoscale poses a potential occupational health hazard for workers. However, current literature lacks comprehensive characterization of TIG welding fume particles. Even less is known about welding fumes generated by welding apprentices with little experience in welding. We characterized TIG welding fume generated by apprentice welders (N = 20) in a ventilated exposure cabin. Exposure assessment was conducted for each apprentice welder at the breathing zone (BZ) inside of the welding helmet and at a near-field (NF) location, 60cm away from the welding task. We characterized particulate matter (PM4), particle number concentration and particle size, particle morphology, chemical composition, reactive oxygen species (ROS) production potential, and gaseous components. The mean particle number concentration at the BZ was 1.69E+06 particles cm−3, with a mean geometric mean diameter of 45nm. On average across all subjects, 92% of the particle counts at the BZ were below 100nm. We observed elevated concentrations of tungsten, which was most likely due to electrode consumption. Mean ROS production potential of TIG welding fumes at the BZ exceeded average concentrations previously found in traffic-polluted air. Furthermore, ROS production potential was significantly higher for apprentices that burned their metal during their welding task. We recommend that future exposure assessments take into consideration welding performance as a potential exposure modifier for apprentice welders or welders with minimal training. PMID:26464505

  4. A purification process for an inert gas system

    International Nuclear Information System (INIS)

    Raj, S.S.; Samanta, S.K.; Jain, N.G.; Deshingkar, D.S.; Ramaswamy, M.

    1984-01-01

    Special inert atmosphere is desired inside hot cells used for handling radioactive materials. In this report, details of experiments conducted to generate data required for the design of a system for maintaining very low levels of organic and acid vapours, oxygen and moisture in a nitrogen gas inert atmosphere, are described. Several grades of activated charcoals impregnated with 1% KOH were studied for the adsorption of acidic and organic vapours. A Pd/Al 2 O 3 catalyst was developed to remove oxygen with greater than 90% efficiency. For the removal of moisture, a regenerable molecular sieve 4A dual-bed was provided. Based on the performance data thus generated, an integrated purification system for nitrogen gas is proposed. (author)

  5. Status of the inert matrix fuel program at PSI

    International Nuclear Information System (INIS)

    Ledergerber, G.; Degueldre, C.; Kasemeyer, U.; Stanculescu, A.; Paratte, J.M.; Chawla, R.

    1997-01-01

    Incineration of plutonium by a once-through cycle in LWRs utilising an inert matrix based fuel may prove to be an attractive way of making use of the energy of fissile plutonium and reducing both the hazard potential and the volumes of the waste. Yttria stabilised zirconia forms a solid solution with oxides of rare earth elements (e.g. erbium, cerium) and some actinides. The small absorption cross section, the excellent stability under irradiation, and the insolubility in acids and water recommends this material as an inert matrix. Neutronics calculations with erbium as burnable poison show that these compositions would be optimal from the reactivity point of view. A fuel element with an improved reactivity behaviour over its life cycle has been designed for possible introduction into a heterogeneous LWR core. (author). 16 refs., 1 tab., 10 figs

  6. The Ages in a Self-Suspended Nanoparticle Liquid

    KAUST Repository

    Agarwal, Praveen

    2010-01-13

    Telomers ionically tethered to nanometer-sized particles yield self-suspended, nanoparticle-Iaden liquids with unusual dynamical features. By subjecting these suspensions to controlled, modest shear strains, we find that their flow behaviors observed using experiments performed on time scales of tens of seconds can be projected to obtain maps of their dynamical response on geological time scales. That such extraordinarily slow dynamic processes can be uncovered from real-time measurements by simply stretching a system provides a simple but powerful tool for interrogating extremely slow motions in other jammed physical states. © 2010 American Chemical Society.

  7. Epileptiform activity during inert gas euthanasia of mice.

    Science.gov (United States)

    Gent, Thomas C; Detotto, Carlotta; Vyssotski, Alexei L; Bettschart-Wolfensberger, Regula

    2018-01-01

    Carbon dioxide (CO2) is one of the most commonly used euthanasia agents for mice, yet it is highly aversive and nociceptive. Inert gases are a possible alternative, however there are qualitative reports of seizures resulting from exposure. Here we evaluate epileptiform activity caused by inert gases (N2, He, Ar and Xe) and CO2 in mice chronically instrumented for EEG/EMG undergoing single-gas euthanasia. We found that N2, He and Ar caused epileptiform activity in all animals, CO2 in half of animals and no epileptiform activity produced by Xe. Atmospheric O2 concentrations at epileptiform activity onset were significantly higher for CO2 than for all other gases and occurred soon after loss of motion, whereas N2 and Ar epileptiform activity occurred at cessation of neocortical activity. Helium caused the longest epileptiform activity and these commenced significantly before isoelectric EEG. We did not detect any epileptiform activity during active behaviour. Taken together, these results demonstrate that whilst epileptiform activity from inert gases and particularly Ar and N2 are more prevalent than for CO2, their occurrence at the onset of an isoelectric EEG is unlikely to impact on the welfare of the animal. Epileptiform activity from these gases should not preclude them from further investigation as euthanasia agents. The genesis of epileptiform activity from CO2 is unlikely to result from hypoxia as with the inert gases. Helium caused epileptiform activity before cessation of neocortical activity and for a longer duration and is therefore less suitable as an alternative to CO2.

  8. Passive and active vibration isolation systems using inerter

    Science.gov (United States)

    Alujević, N.; Čakmak, D.; Wolf, H.; Jokić, M.

    2018-03-01

    This paper presents a theoretical study on passive and active vibration isolation schemes using inerter elements in a two degree of freedom (DOF) mechanical system. The aim of the work is to discuss basic capabilities and limitations of the vibration control systems at hand using simple and physically transparent models. Broad frequency band dynamic excitation of the source DOF is assumed. The purpose of the isolator system is to prevent vibration transmission to the receiving DOF. The frequency averaged kinetic energy of the receiving mass is used as the metric for vibration isolation quality. It is shown that the use of inerter element in the passive vibration isolation scheme can enhance the isolation effect. In the active case, a feedback disturbance rejection scheme is considered. Here, the error signal is the receiving body absolute velocity which is directly fed to a reactive force actuator between the source and the receiving bodies. In such a scheme, the so-called subcritical vibration isolation problems exist. These problems are characterised by the uncoupled natural frequency of the receiving body larger than the uncoupled natural frequency of the source body. In subcritical vibration isolation problems, the performance of the active control is limited by poor stability margins. This is because the stable feedback gain is restricted in a narrow range between a minimum and a maximum. However, with the inclusion of an inerter in the isolator, one of the two stability margins can be opened. This enables large, theoretically unlimited negative feedback gains and large active damping of the receiving body vibration. A simple expression for the required inertance is derived.

  9. Arc melting in inert gas atmosphere of zirconium sponge

    International Nuclear Information System (INIS)

    Julio Junior, O.; Andrade, A.H.P. de

    1991-01-01

    The obtainment of metallic zirconium in laboratory scale with commercial and nuclear quality is the objective of the Metallurgy Department of IEN/CNEN - Brazil, so a melting procedure of zirconium sponge in laboratory scale using an arc furnace in inert atmosphere is developed. The effects of atmosphere operation, and the use of gas absorber and the sponge characteristics over the quality of button in as-cast reporting with hardness measures are described. (C.G.C.)

  10. An inert 3D emulsification device for individual precipitation and concentration of amorphous drug nanoparticles.

    Science.gov (United States)

    Lorenz, T; Bojko, S; Bunjes, H; Dietzel, A

    2018-02-13

    Nanosizing increases the specific surface of drug particles, leading to faster dissolution inside the organism and improving the bioavailability of poorly water-soluble drugs. A novel approach for the preparation of drug nanoparticles in water using chemically inert microfluidic emulsification devices is presented in this paper. A lithographic fabrication sequence was established, allowing fabrication of intersecting and coaxial channels of different depths in glass as is required for 3D flow-focusing. Fenofibrate was used as a model for active pharmaceutical ingredients with very low water solubility in the experiments. It was dissolved in ethyl acetate and emulsified in water, as allowed by the 3D flow-focusing geometry. In the thread formation regime, the drug solution turned into monodisperse droplets of sizes down to below 1 μm. Fast supersaturation occurs individually in each droplet, as the disperse phase solvent progressively diffuses into the surrounding water. Liquid antisolvent precipitation results in highly monodisperse and amorphous nanoparticles of sizes down to 128 nm which can be precisely controlled by the continuous and disperse phase pressure. By comparing optically measured droplet sizes with particle sizes by dynamic light scattering, we could confirm that exactly one particle forms in every droplet. Furthermore, a downstream on-chip concentration allowed withdrawal of major volumes of only the continuous phase fluid which enabled an increase of particle concentration by up to 250 times.

  11. A New Measure for Transported Suspended Sediment

    Science.gov (United States)

    Yang, Q.

    2017-12-01

    Non-uniform suspended sediment plays an important role in many geographical and biological processes. Despite extensive study, understanding to it seems to stagnate when times to consider non-uniformity and non-equilibrium scenarios comes. Due to unsatisfactory reproducibility, large-scaled flume seems to be incompetent to conduct more fundamental research in this area. To push the realm a step further, experiment to find how suspended sediment exchanges is conducted in a new validated equipment, in which turbulence is motivated by oscillating grids. Analysis shows that 1) suspended sediment exchange is constrained by ωS invariance, 2) ωS of the suspended sediment that certain flow regime could support is unique regardless of the sediment gradation and 3) the more turbulent the flow, the higher ωS of the suspension the flow could achieve. A new measure for suspended sediment ωS, the work required to sustain sediment in suspension transport mode if multiplied by gravitational acceleration, is thus proposed to better describe the dynamics of transported suspended sediment. Except for the further understanding towards suspended sediment transportation mechanics, with this energy measure, a strategy to distribute total transport capacity to different fractions could be derived and rational calculation of non-uniform sediment transport capacity under non-equilibrium conditions be possible.

  12. Preparation of mesoporous zirconia microspheres as inert matrix

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Ting [State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China); Wang, Chen; Lv, Jinlong [Beijing Key Laboratory of Fine Ceramics, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China); Liang, Tongxiang, E-mail: txliang@tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing, 100084 (China)

    2016-12-01

    Mesoporous zirconia microspheres, with a diameter of 900 μm, were prepared as an inert accelerator driven system (ADS) transmutation element matrix by the sol-gel method. The purpose of mesopores is to improve the adsorption capacity of inert matrix fuel (IMF) for minor actinides. The study indicated that the mesoporous zirconia performance was improved after the microspheres were hydrothermally treated at 150 °C, the specific surface area increased from 28.29 m{sup 2}/g to 61.28 m{sup 2}/g, and hydrothermal treatment avoided the cracking of the microspheres. Pre-decomposition of the organics during the hydrothermal process stabilized the mesoporous structure. The average pore diameter of mesoporous microsphere was 14.3 nm. - Highlights: • Mesoporous zirconia microspheres with a diameter of 900 μm were prepared as ADS transmutation element inert matrix. • The mesoporous performance was improved after the microspheres were hydrothermally treated at 150 °C. • The specific surface area increased from 28.29 m{sup 2}/g to 61.28 m{sup 2}/g. • The hydrothermal treatment could avoid the cracking of the microspheres. • The specific surface area of mesoporous microsphere was 61.28 m{sup 2}/g and the average pore diameter was 14.3 nm.

  13. Removal of the Inert Organic Fraction of Municipal Wastewater Using the Integrated Activated Sludge/Trickling Filter System

    Directory of Open Access Journals (Sweden)

    mehraban sadeghi

    2015-01-01

    Full Text Available The discharge of phenol and chlorinated compounds, fatty acids, tannin, lignin, and their by-products into receptive waters poses serious hazards for the aquatic life. In this study, the efficiency of a tow-step process of activated sludge-trickling filter (AS/TF in the removal of inert chemical materials that defy conventional treatment processes was investigated. For this purpose, an integrated activated sludge process (industrial scale was used sequentially with a trickling filter (pilot scale. Inside a tank with an effective volume of 6.87 m3 was installed 5.78 m3 of polypropylene 2HX media with a specific area of 240 m2/m3. The hydraulic loading rate (HLR of the trickling filter during the startup period (90 days was 3.6 m3/h which was raised to 3.6-6 m3/h in the operation period (120 days, with the best effluent quality achieved at HLR=5.4 m3/h. For the purposes of the experiments in this study, four reactors, each 1256 cm3 in volume, were fed the WWTP effluent and concurrently a glucose substrate containing a COD content equal to that fed to the four reactors was fed into two identical reactors; all the reactors were subsequently run for 480 h in aerobic conditions. Nutrients, pH, and DO (as environmental control indicators as well as soluble and total COD were measured twice daily. The effluent values of soluble inert materials (SI, total soluble COD (STO, degradable suspended materials (XSO, degradable COD (CSO, refractory suspended materials (XI, and degradable soluble materials (SSO for AS were calculated as 40, 227, 94, 281, 251, and 187, respectively, while the same parameters for the AS/TF were 20, 227, 104, 311, 241, and 207 mg/l, respectively. The results showed that the activated sludge process when combined with the trickling filter has a twofold capability, compared to when used alone, in removing inert COD. It was also shown that treatment levels in conventional WWTPs can be improved by integrating conventional treatment

  14. Experimental observations of effects of inert gas on cavity formation during irradiation

    International Nuclear Information System (INIS)

    Farrell, K.

    1980-04-01

    Cavity (void) formation and swelling in non-fissile materials during neutron irradiation and charged particle bombardments are reviewed. Helium is the most important inert gas and is primarily active as a cavity nucleant. It also enhances formation of dislocation structure. Preimplantation of helium overstimulates cavity nucleation and gives a different temperature response of swelling than when helium is coimplanted during the damage process. Helium affects, and is affected by, radiation-induced phase instability. Many of these effects are explainable in terms of cavity nucleation on submicroscopic critical size gas bubbles, and on the influence of the neutral sink strength of such bubbles. Titanium and zirconium resist cavity formation when vacancy loops are present

  15. Experimental observations of effects of inert gas on cavity formation during irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, K.

    1980-04-01

    Cavity (void) formation and swelling in non-fissile materials during neutron irradiation and charged particle bombardments are reviewed. Helium is the most important inert gas and is primarily active as a cavity nucleant. It also enhances formation of dislocation structure. Preimplantation of helium overstimulates cavity nucleation and gives a different temperature response of swelling than when helium is coimplanted during the damage process. Helium affects, and is affected by, radiation-induced phase instability. Many of these effects are explainable in terms of cavity nucleation on submicroscopic critical size gas bubbles, and on the influence of the neutral sink strength of such bubbles. Titanium and zirconium resist cavity formation when vacancy loops are present.

  16. Heavy metal ions adsorption by suspended particle and sediment of ...

    African Journals Online (AJOL)

    Nowadays, it is important to evaluate the self-purifying capacity of rivers because of the different kinds of pollutants discharged into them. Important kind of pollutants and heavy metals exist in wastewaters industries. When the Sorb Dona mine is placed in Upper Chalus River, in the west of Mazandaran, products of mine ...

  17. Monosaccharide composition of suspended particles from the Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Sankaran, P.D.; Wagh, A.B.

    , fucose, ribose, arabinose and xylose showed large variations and were generally abundant at greater depths ( 100 m). Glucose contribution to the total carbohydrates, especially at higher depths ( 100 m) was relatively less than that reported from other...

  18. Concentration of elements in suspended matter discharges to Lerma River, Mexico

    International Nuclear Information System (INIS)

    Avila-Perez, P.; Tejeda, S.; Carapia, L.; Barcelo-Quintal, I.; Martinez, T.

    2011-01-01

    The S, K, Ca, Ti, V, Cr, Mn, Fe, Cu, Zn and Pb concentration and the elemental composition of particles in suspended matter from principal discharges to Lerma River, have been evaluated. The elemental concentration in suspended matter has been obtained by Energy Dispersive X-Ray Fluorescence Spectrometry. The elemental composition of particles has been obtained by means of Energy Dispersive X-Ray Spectrometry (EDS). The results show that K, Ca, Ti, Mn and Fe are mainly from natural origin in the Upper Course of the Lerma River (UCLR), where the principal contributions probably come from dragging of soils and sediments in the rainy season and Cr, Cu, Zn and Pb are mainly from anthropogenic origin where the principal contributions come from urban and industrial untreated discharge. The application of Energy Dispersive X-Ray Spectrometry plus Scanning Electron Microscopy is useful in the characterization of suspended matter in natural, anthropogenic and mixed water discharges. (author)

  19. Transcatheter embolization of renal neoplasms. A comparison of the merits of the radio-active infarct implant versus total embolization with inert material

    International Nuclear Information System (INIS)

    Lang, E.K.; Pisco, J.M.

    1980-01-01

    Transcatheter embolization with radio-active infarct particles and inert embolic material has been proposed for adjuvant therapy in the management of renal cell carcinoma. Transcatheter embolization with inert embolic material has been advocated in preparation for surgical resection of renal tumours. Embolization with radio-active infarct particles is undertaken to deliver a tumouricidal dose to the primary neoplasm. The resultant interstitial implant offers the advantage of a high dose to the primary tumour, choice of time of delivery of the radiant energy by selection of a radio-isotope with appropriate half-life, and limitation of the integral dose to the patient by selection of appropriate physical characteristics of the radio-isotope utilized. Transcatheter embolization with radio-active infarct particles is advocated either as definitive therapy for clearly inoperable neoplasms, or in hope to make an initially inoperable neoplasm operable. (Auth.)

  20. Minimum ignition energy of nano and micro Ti powder in the presence of inert nano TiO₂ powder.

    Science.gov (United States)

    Chunmiao, Yuan; Amyotte, Paul R; Hossain, Md Nur; Li, Chang

    2014-06-15

    The inerting effect of nano-sized TiO2 powder on ignition sensitivity of nano and micro Ti powders was investigated with a Mike 3 apparatus. "A little is not good enough" is also suitable for micro Ti powders mixed with nano-sized solid inertants. MIE of the mixtures did not significantly increase until the TiO2 percentage exceeded 50%. Nano-sized TiO2 powders were ineffective as an inertant when mixed with nano Ti powders, especially at higher dust loadings. Even with 90% nano TiO2 powder, mixtures still showed high ignition sensitivity because the statistic energy was as low as 2.1 mJ. Layer fires induced by ignited but unburned metal particles may occur for micro Ti powders mixed with nano TiO2 powders following a low level dust explosion. Such layer fires could lead to a violent dust explosion after a second dispersion. Thus, additional attention is needed to prevent metallic layer fires even where electric spark potential is low. In the case of nano Ti powder, no layer fires were observed because of less flammable material involved in the mixtures investigated, and faster flame propagation in nanoparticle clouds. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Development of a field test method for total suspended solids analysis.

    Science.gov (United States)

    2013-11-01

    Total suspended solids (TSS) are all particles in water that will not pass through a glass fiber filter with a pore size less : than 2 m, including sediments, algae, nutrients, and metals. TSS is an important water quality parameter because of its ...

  2. Observations of suspended sediment from ADCP and OBS measurements in a mud-dominated environment

    NARCIS (Netherlands)

    Hoitink, A.J.F.; Hoekstra, P.

    2005-01-01

    The ability of a 1.2-MHz Acoustic Doppler Current Profiler (ADCP) to measure suspended sediment concentration (SSC) and particle size variation in a mud-dominated environment has been investigated. Experiments were conducted in the Bay of Banten, Indonesia, where clays and silts in the range of 3-55

  3. Radiative corrections to the triple Higgs coupling in the inert Higgs doublet model

    International Nuclear Information System (INIS)

    Arhrib, Abdesslam; Benbrik, Rachid; Falaki, Jaouad El; Jueid, Adil

    2015-01-01

    We investigate the implication of the recent discovery of a Higgs-like particle in the first phase of the LHC Run 1 on the Inert Higgs Doublet Model (IHDM). The determination of the Higgs couplings to SM particles and its intrinsic properties will get improved during the new LHC Run 2 starting this year. The new LHC Run 2 would also shade some light on the triple Higgs coupling. Such measurement is very important in order to establish the details of the electroweak symmetry breaking mechanism. Given the importance of the Higgs couplings both at the LHC and e + e − Linear Collider machines, accurate theoretical predictions are required. We study the radiative corrections to the triple Higgs coupling hhh and to hZZ, hWW couplings in the context of the IHDM. By combining several theoretical and experimental constraints on parameter space, we show that extra particles might modify the triple Higgs coupling near threshold regions. Finally, we discuss the effect of these corrections on the double Higgs production signal at the e + e − LC and show that they can be rather important.

  4. Searches for Dark Matter via Mono-W Production in Inert Doublet Model at the LHC

    Science.gov (United States)

    Wan, Neng; Li, Niu; Zhang, Bo; Yang, Huan; Zhao, Min-Fu; Song, Mao; Li, Gang; Guo, Jian-You

    2018-05-01

    The Inert Doublet Model (IDM) is one of the many beyond Standard Model scenarios with an extended scalar sector, which provide a suitable dark matter particle candidate. Dark matter associated visible particle production at high energy colliders provides a unique way to determine the microscopic properties of the dark matter particle. In this paper, we investigate that the mono-W + missing transverse energy production at the Large Hadron Collider (LHC), where W boson decay to a lepton and a neutrino. We perform the analysis for the signal of mono-W production in the IDM and the Standard Model (SM) backgrounds, and the optimized criteria employing suitable cuts are chosen in kinematic variables to maximize signal significance. We also investigate the discovery potential in several benchmark scenarios at the 14 TeV LHC. When the light Z2 odd scalar higgs of mass is about 65 GeV, charged Higgs is in the mass range from 120 GeV to 250 GeV, it provides the best possibility with a signal significance of about 3σ at an integrated luminosity of about 3000 fb‑1. Supported by the National Natural Science Foundation of China under Grant Nos. 11205003, 11305001, 11575002, the Key Research Foundation of Education Ministry of Anhui Province of China under Grant Nos. KJ2017A032, KJ2016A749, KJ2013A260, and Natural Science Foundation of West Anhui University under Grant No. WXZR201614

  5. Methanol Droplet Combustion in Oxygen-Inert Environments in Microgravity

    Science.gov (United States)

    Nayagam, Vedha; Dietrich, Daniel L.; Hicks, Michael C.; Williams, Forman A.

    2013-01-01

    The Flame Extinguishment (FLEX) experiment that is currently underway in the Combustion Integrated Rack facility onboard the International Space Station is aimed at understanding the effects of inert diluents on the flammability of condensed phase fuels. To this end, droplets of various fuels, including alkanes and alcohols, are burned in a quiescent microgravity environment with varying amounts of oxygen and inert diluents to determine the limiting oxygen index (LOI) for these fuels. In this study we report experimental observations of methanol droplets burning in oxygen-nitrogen-carbon dioxide and oxygen-nitrogen-helium gas mixtures at 0.7 and 1 atmospheric pressures. The initial droplet size varied between approximately 1.5 mm and 4 mm to capture both diffusive extinction brought about by insufficient residence time at the flame and radiative extinction caused by excessive heat loss from the flame zone. The ambient oxygen concentration varied from a high value of 30% by volume to as low as 12%, approaching the limiting oxygen index for the fuel. The inert dilution by carbon dioxide and helium varied over a range of 0% to 70% by volume. In these experiments, both freely floated and tethered droplets were ignited using symmetrically opposed hot-wire igniters and the burning histories were recorded onboard using digital cameras, downlinked later to the ground for analysis. The digital images yielded droplet and flame diameters as functions of time and subsequently droplet burning rate, flame standoff ratio, and initial and extinction droplet diameters. Simplified theoretical models correlate the measured burning rate constant and the flame standoff ratio reasonably well. An activation energy asymptotic theory accounting for time-dependent water dissolution or evaporation from the droplet is shown to predict the measured diffusive extinction conditions well. The experiments also show that the limiting oxygen index for methanol in these diluent gases is around 12% to

  6. An electromagnetic inerter-based vibration suppression device

    International Nuclear Information System (INIS)

    Gonzalez-Buelga, A; Clare, L R; Neild, S A; Jiang, J Z; Inman, D J

    2015-01-01

    This paper describes how an inerter-based device for structural vibration suppression can be realized using an electromagnetic transducer such as a linear motor. When the motor shaft moves, a difference of voltage is generated across the transducer coil. The voltage difference is proportional to the relative velocity between its two terminals. The electromagnetic transducer will exert a force proportional to current following the Lorentz principle if the circuit is closed around the transducer coil. If an electronic circuit consisting of a capacitor, an inductance and a resistance with the appropriate configuration is connected, the resulting force reflected back into the mechanical domain is equivalent to that achieved by a mechanical inerter-based device. The proposed configuration is easy to implement and very versatile, provided a high quality conversion system with negligible losses. With the use of electromagnetic devices, a new generation of vibration absorbers can be realized, for example in the electrical domain it would be relatively uncomplicated to synthesize multi-frequency or real time tunable vibration absorbers by adding electrical components in parallel. In addition by using resistance emulators in the electrical circuits, part of the absorbed vibration energy can be converted into usable power. Here an electromagnetic tuned inerter damper (E-TID) is tested experimentally using real time dynamic substructuring. A voltage compensation unit was developed in order to compensate for coil losses. This voltage compensation unit requires power, which is acquired through harvesting from the vibration energy using a resistance emulator. A power balance analysis was developed in order to ensure the device can be self sufficient. Promising experimental results, using this approach, have been obtained and are presented in this paper. The ultimate goal of this research is the development of autonomous electromagnetic vibration absorbers, able to harvest energy

  7. Nuclear Technology. Course 28: Welding Inspection. Module 28-3, Tungsten Inert Gas (TIG), Metal Inert Gas (MIG) and Submerged Arc Welding.

    Science.gov (United States)

    Espy, John

    This third in a series of ten modules for a course titled Welding Inspection presents the apparatus, process techniques, procedures, applications, associated defects, and inspection for the tungsten inert gas, metal inert gas, and submerged arc welding processes. The module follows a typical format that includes the following sections: (1)…

  8. Nucleosynthesis confronts an unstable inert 17 keV state

    International Nuclear Information System (INIS)

    Enqvist, K.; Kainulainen, K.; Thomson, M.

    1991-01-01

    We study the cosmological consequences of an inert 17 keV state mixing with the electron neutrino. We find that the nucleosynthesis upper bound on the primordial helium abundance prohibits the existence of such a state, unless its lifetime falls into the range 6x10 -4 s vac -2 s. In this range the decay occurs after the chemical decoupling of the electron neutrinos and before the beginning of the nucleosynthesis, with the result that the predicted helium abundance can be lower than what it would be in the standard scenario. (orig.)

  9. Electrolytic 99TcO4- reduction at inert electrodes

    International Nuclear Information System (INIS)

    Kremer, C.; Gambino, D.; Leon, A.; Kremer, E.

    1990-01-01

    Electrolytic pertechnetate reduction at inert electrodes was studied as an alternative procedure for synthesizing Tc complexes. Pertechnetate reduction was carried out in aqueous media using different aminated ligands (en, dien, trien and 1,3-dap) forming [TcO 2 (amine) 2 ] + type complexes. Simultaneously with synthesis of the desired Tc complex, TcO 2 was electrodeposited onto the cathode. Conversion of TcO 4 - to Tc complex and TcO 2 was studied as a function of several variables (kind and concentration of supporting electrolyte, ligand concentration, pH, current and electrolysis time). (author) 9 refs.; 6 figs.; 1 tab

  10. Separation of Nuclear Fuel Surrogates from Silicon Carbide Inert Matrix

    International Nuclear Information System (INIS)

    Baney, Ronald

    2008-01-01

    The objective of this project has been to identify a process for separating transuranic species from silicon carbide (SiC). Silicon carbide has become one of the prime candidates for the matrix in inert matrix fuels, (IMF) being designed to reduce plutonium inventories and the long half-lives actinides through transmutation since complete reaction is not practical it become necessary to separate the non-transmuted materials from the silicon carbide matrix for ultimate reprocessing. This work reports a method for that required process

  11. Vector boson fusion in the inert doublet model

    Science.gov (United States)

    Dutta, Bhaskar; Palacio, Guillermo; Restrepo, Diego; Ruiz-Álvarez, José D.

    2018-03-01

    In this paper we probe the inert Higgs doublet model at the LHC using vector boson fusion (VBF) search strategy. We optimize the selection cuts and investigate the parameter space of the model and we show that the VBF search has a better reach when compared with the monojet searches. We also investigate the Drell-Yan type cuts and show that they can be important for smaller charged Higgs masses. We determine the 3 σ reach for the parameter space using these optimized cuts for a luminosity of 3000 fb-1 .

  12. Re-derived overclosure bound for the inert doublet model

    Science.gov (United States)

    Biondini, S.; Laine, M.

    2017-08-01

    We apply a formalism accounting for thermal effects (such as modified Sommerfeld effect; Salpeter correction; decohering scatterings; dissociation of bound states), to one of the simplest WIMP-like dark matter models, associated with an "inert" Higgs doublet. A broad temperature range T ˜ M/20 . . . M/104 is considered, stressing the importance and less-understood nature of late annihilation stages. Even though only weak interactions play a role, we find that resummed real and virtual corrections increase the tree-level overclosure bound by 1 . . . 18%, depending on quartic couplings and mass splittings.

  13. Triheterometallic Lanthanide Complexes Prepared from Kinetically Inert Lanthanide Building Blocks

    DEFF Research Database (Denmark)

    Sørensen, Thomas Just; Tropiano, Manuel; Kenwright, Alan M.

    2017-01-01

    Three molecular structures, each containing three different lanthanide(III) centres, have been prepared by coupling three kinetically inert lanthanide(III) complexes in an Ugi reaction. These 2 kDa molecules were purified by dialysis and characterised by NMR and luminescence techniques. The photo...... and lanthanide(III) centres in these molecules inhibits the efficient sensitisation of europium. We conclude that the intramolecular collisions required for efficient Dexter energy transfer from the sensitiser to the lanthanide(III) centre can be prevented by steric congestion....

  14. Continuous-flow centrifugation to collect suspended sediment for chemical analysis

    Science.gov (United States)

    Conn, Kathleen E.; Dinicola, Richard S.; Black, Robert W.; Cox, Stephen E.; Sheibley, Richard W.; Foreman, James R.; Senter, Craig A.; Peterson, Norman T.

    2016-12-22

    polychlorinated biphenyls. The particle-size distribution of the captured sediment changes to a more fine-grained sample during centrifugation, and the necessity to account for this change when extrapolating chemical concentrations on the centrifuged sediment sample to the environmental water system is discussed.The data produced using this method will help eliminate a data gap of suspended sediment-bound chemical concentrations, and will support management decisions, such as chemical source-control efforts or in-stream restoration activities. When coupled with streamflow and sediment flux data, it will improve estimates of riverine chemical fluxes, and will aid in assessing the importance and impacts of suspended sediment-bound chemicals to downstream freshwater and coastal marine ecosystems.

  15. Modelling the transport of suspended particulate matter by the Rhone River plume (France). Implications for pollutant dispersion

    International Nuclear Information System (INIS)

    Perianez, R.

    2005-01-01

    A model to simulate the transport of suspended particulate matter by the Rhone River plume has been developed. The model solves the 3D hydrodynamic equations, including baroclinic terms and a 1-equation turbulence model, and the suspended matter equations including advection/diffusion of particles, settling and deposition. Four particle classes are considered simultaneously according to observations in the Rhone. Computed currents, salinity and particle distributions are, in general, in good agreement with observations or previous calculations. The model also provides sedimentation rates and the distribution of different particle classes over the sea bed. It has been found that high sedimentation rates close to the river mouth are due to coarse particles that sink rapidly. Computed sedimentation rates are also similar to those derived from observations. The model has been applied to simulate the transport of radionuclides by the plume, since suspended matter is the main vector for them. The radionuclide transport model, previously described and validated, includes exchanges of radionuclides between water, suspended matter and bottom sediment described in terms of kinetic rates. A new feature is the explicit inclusion of the dependence of kinetic rates upon salinity. The model has been applied to 137 Cs and 239,240 Pu. Results are, in general, in good agreement with observations. - A model has been developed to simulate transport of suspended particulate matter in the Rhone River plume

  16. A scintillation detector for measuring inert gas beta rays

    International Nuclear Information System (INIS)

    Shi Hengchang; Yu Yunchang

    1989-10-01

    The inert gas beta ray scintillation detector, which is made of organic high polymers as the base and coated with compact fluorescence materials, is a lower energy scintillation detector. It can be used in the nuclear power plant and radioactive fields as a lower energy monitor to detect inert gas beta rays. Under the conditions of time constant 10 minutes, confidence level is 99.7% (3σ), the intensity of gamma rays 2.6 x 10 -7 C/kg ( 60 Co), and the minimum detectable concentration (MDC) of this detector for 133 Xe 1.2 Bq/L. The measuring range for 133 Xe is 11.1 ∼ 3.7 x 10 4 Bq/L. After a special measure is taken, the device is able to withstand 3 x 10 5 Pa gauge pressure. In the loss-of-cooolant-accident, it can prevent the radioactive gas of the detector from leaking. This detector is easier to be manufactured and decontaminated

  17. Plutonium fuel lattice neutron behavior in inert matrix

    International Nuclear Information System (INIS)

    Hernandez L, H.; Lucatero, M. A.

    2010-10-01

    In several countries is had been researching the possibility of using plutonium, as weapon degree as reactor degree, as fuel material in commercial reactors to generate electricity. In special a great development has been in Pressure Water Reactors. However, in Mexico the reactors are Boiling Water Reactors type, reason for which the necessity to considers feasibility to use this fuel type in the reactors of nuclear power plant of Laguna Verde. For this propose a comparison of fuel lattice that compose a fuel assembly is made. The fuel assembly will propose to be used whit in the reactor present different inert matrix, as well as burnable poison. The material that compose the inert matrices used are cerium and zirconia (CeO 2 and ZrO 2 ) and as burnable poisons have gadolinium and erbium (Gd 2 O 4 and ErO 2 ). As far as the hydraulic design used is a cell 10 X 10 with two water channels. The lattice calculations are made with the Helios code a library with 35 energy groups, having determined the pin power factors, the infinite multiplication factor and the neutron flux profiles. (Author)

  18. Pyrosequencing Reveals Bacterial Communities in Unchlorinated Drinking Water Distribution System: An Integral Study of Bulk Water, Suspended Solids, Loose Deposits, and Pipe Wall Biofilm

    KAUST Repository

    Liu, G.; Bakker, G. L.; Li, S.; Vreeburg, J. H G; Verberk, J. Q J C; Medema, G. J.; Liu, W. T.; Van Dijk, J. C.

    2014-01-01

    The current understanding of drinking water distribution system (DWDS) microbiology is limited to pipe wall biofilm and bulk water; the contributions of particle-associated bacteria (from suspended solids and loose deposits) have long been neglected

  19. Estimation of suspended sediment concentration in rivers using acoustic methods.

    Science.gov (United States)

    Elçi, Sebnem; Aydin, Ramazan; Work, Paul A

    2009-12-01

    Acoustic Doppler current meters (ADV, ADCP, and ADP) are widely used in water systems to measure flow velocities and velocity profiles. Although these meters are designed for flow velocity measurements, they can also provide information defining the quantity of particulate matter in the water, after appropriate calibration. When an acoustic instrument is calibrated for a water system, no additional sensor is needed to measure suspended sediment concentration (SSC). This provides the simultaneous measurements of velocity and concentration required for most sediment transport studies. The performance of acoustic Doppler current meters for measuring SSC was investigated in different studies where signal-to-noise ratio (SNR) and suspended sediment concentration were related using different formulations. However, these studies were each limited to a single study site where neither the effect of particle size nor the effect of temperature was investigated. In this study, different parameters that affect the performance of an ADV for the prediction of SSC are investigated. In order to investigate the reliability of an ADV for SSC measurements in different environments, flow and SSC measurements were made in different streams located in the Aegean region of Turkey having different soil types. Soil samples were collected from all measuring stations and particle size analysis was conducted by mechanical means. Multivariate analysis was utilized to investigate the effect of soil type and water temperature on the measurements. Statistical analysis indicates that SNR readings ob tained from the ADV are affected by water temperature and particle size distribution of the soil, as expected, and a prediction model is presented relating SNR readings to SSC mea surements where both water temperature and sediment characteristics type are incorporated into the model. The coefficients of the suggested model were obtained using the multivariate anal ysis. Effect of high turbidity

  20. Aerosol release from a hot sodium pool and behaviour in inert gas atmosphere

    International Nuclear Information System (INIS)

    Sauter, H.; Schuetz, W.

    1986-01-01

    In the KfK-NALA program, experiments were carried out on the subject of aerosol release from a contaminated sodium pool into inert gas atmosphere under various conditions. Besides the determination of retention factors for fuel and fission products, the sodium aerosol system was investigated and characterized, concerning aerosol generation (evaporation rate), particle size, mass concentration, and deposition behaviour. Pool temperatures were varied between 700 and 1000 K at different geometrical and convective conditions. Technical scale experiments with a 531-cm 2 pool surface area were performed at natural convection in a 2.2-m 3 heated vessel, as well as additional small scale experiments at forced convection and 38.5-cm 2 pool surface area. A best-fit formula is given for the specific evaporation rate into a 400 K argon atmosphere. Approximately, the very convenient relation (dm/dt) (kg/m 2 /h) = 0.1 p (mm Hg) was found. The sodium aerosol diameter lay between 0.6 μm, less than 1 sec after production, and 2.5 μm at maximum concentration. The deposition behaviour was characterized by very small quantities ( 80%) on the bottom cover of the vessel. In the model theoretic studies with the PARDISEKO code, calculations were performed of the mass concentration, particle diameter and deposition behaviour. Agreement with the experimental values could not be achieved until a modulus was introduced to allow for turbulent deposition. (author)

  1. Microstructure and magnetic properties of inert gas atomized rare earth permanent magnetic materials

    International Nuclear Information System (INIS)

    Sellers, C.H.; Hyde, T.A.; Branagan, D.J.; Lewis, L.H.; Panchanathan, V.

    1997-01-01

    Several permanent magnet alloys based on the ternary Nd 2 Fe 14 B (2-14-1) composition have been prepared by inert gas atomization (IGA). The microstructure and magnetic properties of these alloys have been studied as a function of particle size, both before and after heat treatment. Different particle sizes have characteristic properties due to the differences in cooling rate experienced during solidification from the melt. These properties are also strongly dependent on the alloy composition due to the cooling rate close-quote s effect on the development of the phase structure; the use of rare earth rich compositions appears necessary to compensate for a generally inadequate cooling rate. After atomization, a brief heat treatment is necessary for the development of the optimal microstructure and magnetic properties, as seen from the hysteresis loop shape and improvements in key magnetic parameters (intrinsic coercivity H ci , remanence B r , and maximum energy product BH max ). By adjusting alloy compositions specifically for this process, magnetically isotropic powders with good magnetic properties can be obtained and opportunities for the achievement of better properties appear to be possible. copyright 1997 American Institute of Physics

  2. A spectrometer for submicron particles

    International Nuclear Information System (INIS)

    Pourprix, M.

    1995-01-01

    The electrostatic spectrometer for aerosol particles, is composed of two coaxial parallel conductive disks between which an electric field is established; an annular slot in the first disk allows for the atmosphere air intake. Suction and injection systems, and a third intermediate conductive disk are used to carry out a dynamic confinement that allows for the separation of particles having various electronic mobility and the determination of the suspended particle size distribution. Application to aerosol size spectrum determination and air quality monitoring

  3. Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations

    Science.gov (United States)

    Voichick, Nicholas; Topping, David J.; Griffiths, Ronald E.

    2018-03-01

    Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers and erosion in catchments, (4) to manage siltation of water reservoirs, and (5) to establish connections with aquatic biological properties, such as primary production and predator-prey interactions. Turbidity is typically measured with an optical probe that detects light scattered from particles in the water. Probes have defined upper limits of the range of turbidity that they can measure. The general assumption is that when turbidity exceeds this upper limit, the values of turbidity will be constant, i.e., the probe is pegged; however, this assumption is not necessarily valid. In rivers with limited variation in the physical properties of the suspended sediment, at lower suspended-sediment concentrations, an increase in suspended-sediment concentration will cause a linear increase in turbidity. When the suspended-sediment concentration in these rivers is high, turbidity levels can exceed the upper measurement limit of an optical probe and record a constant pegged value. However, at extremely high suspended-sediment concentrations, optical turbidity probes do not necessarily stay pegged at a constant value. Data from the Colorado River in Grand Canyon, Arizona, USA, and a laboratory experiment both demonstrate that when turbidity exceeds instrument-pegged conditions, increasing suspended-sediment concentration (and thus increasing turbidity) may cause optical probes to record decreasing false turbidity values that appear to be within the valid measurement range of the probe. Therefore, under high-turbidity conditions, other surrogate measurements of turbidity (e.g., acoustic-attenuation measurements or suspended-sediment samples) are necessary to

  4. Thermal degradation of CR-39 polymer in an inert atmosphere

    International Nuclear Information System (INIS)

    Kalsi, P.C.; Pandey, A.K.; Iyer, R.H.; Singh Mudher, K.D.

    1995-01-01

    The thermal degradation of CR-39 (allyl diglycol carbonate), a polymer widely used in nuclear science and technology, in an inert atmosphere has been studied using thermogravimetric analysis (TGA) and differential thermal analysis (DTA) techniques. The results are compared with the thermal degradation data of the polymer in an air atmosphere. The present studies showed that the thermal degradation of the polymer proceeds in two steps in an argon atmosphere as compared to three steps in air atmosphere. The mass losses in air are higher than that in argon due to the oxidative decomposition of the residue. The kinetics of the different stages of degradation were also evaluated from the TG curves. (author). 7 refs., 1 tab

  5. Wigner's infinite spin representations and inert matter

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, Bert [CBPF, Rio de Janeiro (Brazil); Institut fuer Theoretische Physik FU-Berlin, Berlin (Germany)

    2017-06-15

    Positive energy ray representations of the Poincare group are naturally subdivided into three classes according to their mass and spin content: m > 0, m = 0 finite helicity and m = 0 infinite spin. For a long time the localization properties of the massless infinite spin class remained unknown, until it became clear that such matter does not permit compact spacetime localization and its generating covariant fields are localized on semi-infinite space-like strings. Using a new perturbation theory for higher spin fields we present arguments which support the idea that infinite spin matter cannot interact with normal matter and we formulate conditions under which this also could happen for finite spin s > 1 fields. This raises the question of a possible connection between inert matter and dark matter. (orig.)

  6. Muon implantation in inert gases studied by radio frequency spectroscopy

    International Nuclear Information System (INIS)

    Johnson, C; Cottrell, S P; Ghandi, K; Fleming, D G

    2005-01-01

    Diamagnetic and muonium (Mu) fractions formed in low-pressure inert gases, by energetic muon implantation, have been studied using the technique of time-delayed radio frequency muon spin resonance (RF-μSR). Results obtained establish the validity of the long-held view that formation of these species is due only to prompt processes, and in turn confirms that the diamagnetic environment is due to a muon molecular ion, MMu + , and not a bare μ + . In addition, polarization fractions for the diamagnetic and Mu environments have been determined at different pressures, thereby complementing earlier data, and demonstrating that the RF-μSR technique provides polarization fractions in good accord with those obtained using conventional transverse-field muon spin resonance measurements

  7. Muon implantation in inert gases studied by radio frequency spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, C [ISIS Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire (United Kingdom); Cottrell, S P [ISIS Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire (United Kingdom); Ghandi, K [TRIUMF and Department of Chemistry, University of British Columbia, Vancouver (Canada); Fleming, D G [TRIUMF and Department of Chemistry, University of British Columbia, Vancouver (Canada)

    2005-01-14

    Diamagnetic and muonium (Mu) fractions formed in low-pressure inert gases, by energetic muon implantation, have been studied using the technique of time-delayed radio frequency muon spin resonance (RF-{mu}SR). Results obtained establish the validity of the long-held view that formation of these species is due only to prompt processes, and in turn confirms that the diamagnetic environment is due to a muon molecular ion, MMu{sup +}, and not a bare {mu}{sup +}. In addition, polarization fractions for the diamagnetic and Mu environments have been determined at different pressures, thereby complementing earlier data, and demonstrating that the RF-{mu}SR technique provides polarization fractions in good accord with those obtained using conventional transverse-field muon spin resonance measurements.

  8. Water fog inerting of hydrogen-air mixtures

    International Nuclear Information System (INIS)

    Zalosh, R.G.; Bajpai, S.N.

    1982-01-01

    Laboratory tests have been conducted to determine the effects of water fog density, droplet diameter and temperature on the lower flammable limit (LFL) of hydrogen-air-steam mixtures. Five different fog nozzles were used to generate dense fogs with volume mean drop diameters ranging from 20 micro-meters to 115 micro-meters. At 20 0 C, these nozzles marginally raised the hydrogen LFL from 4.0 vol.% hydrogen to typically 4.8%, with one exceptional nozzle producing an LFL of 7.2%. At 50 0 C, the LFL in the presence of dense fog ranged from 5.0 to 7.9%, while at 70 0 C, the range was 5.9 to 8.5%. Fog densities required to achieve a given level of partial inerting increased with approximately the second power of average drop diameter, as predicted by a theoretical flame quenching analysis

  9. Collision-induced polarizabilities of inert gas atoms

    International Nuclear Information System (INIS)

    Clarke, K.L.; Madden, P.A.; Buckingham, A.D.

    1978-01-01

    The use of polarizability densities to calculate collision-induced polarizabilities is investigated. One method for computing polarizabilities of inert gas diatoms employs atomic polarizability densities from finite-field Hartree-Fock calculations, together with classical equations for the polarization of dielectrics. It is shown that this model gives inaccurate values for both the local fields and the local response to non-uniform fields. An alternative method incorporating the same physical effects is used to compute the pair polarizabilities to first order in the interatomic interaction. To first order the pair contribution to the trace of the polarizability is negative at short range. The calculated anisotropy does not differ significantly from the DID value, whereas the polarizability density calculation gives a substantial reduction in the anisotropy. (author)

  10. Inert matrix fuel in dispersion type fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Savchenko, A.M. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation)]. E-mail: sav@bochvar.ru; Vatulin, A.V. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Morozov, A.V. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Sirotin, V.L. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Dobrikova, I.V. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Kulakov, G.V. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Ershov, S.A. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Kostomarov, V.P. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation); Stelyuk, Y.I. [A.A. Bochvar All-Russia Research Institute of Inorganic Materials (VNIINM) 123060, P.O. Box 369, Rogova Street, 5A, Moscow (Russian Federation)

    2006-06-30

    The advantages of using inert matrix fuel (IMF) as a dispersion fuel in an aluminium alloy matrix are considered, in particular, low temperatures in the fuel centre, achievable high burn-ups, serviceability in transients and an environmentally friendly process of fuel rod fabrication. Two main versions of IMF are under development at A.A. Bochvar Institute, i.e. heterogeneous or isolated distribution of plutonium. The out-of-pile results on IMF loaded with uranium dioxide as plutonium simulator are presented. Fuel elements with uranium dioxide composition fabricated at A.A. Bochvar Institute are currently under MIR tests (RIAR, Dimitrovgrad). The fuel elements reached a burn-up of 88 MW d kg{sup -1} (equivalent to the burn up of the standard uranium dioxide pelletized fuel) without loss of leak-tightness of the cladding. The feasibility of fabricating IMF of these particular types with plutonium dioxide is considered with a view to in-pile irradiation.

  11. Inert matrix fuel in dispersion type fuel elements

    Science.gov (United States)

    Savchenko, A. M.; Vatulin, A. V.; Morozov, A. V.; Sirotin, V. L.; Dobrikova, I. V.; Kulakov, G. V.; Ershov, S. A.; Kostomarov, V. P.; Stelyuk, Y. I.

    2006-06-01

    The advantages of using inert matrix fuel (IMF) as a dispersion fuel in an aluminium alloy matrix are considered, in particular, low temperatures in the fuel centre, achievable high burn-ups, serviceability in transients and an environmentally friendly process of fuel rod fabrication. Two main versions of IMF are under development at A.A. Bochvar Institute, i.e. heterogeneous or isolated distribution of plutonium. The out-of-pile results on IMF loaded with uranium dioxide as plutonium simulator are presented. Fuel elements with uranium dioxide composition fabricated at A.A. Bochvar Institute are currently under MIR tests (RIAR, Dimitrovgrad). The fuel elements reached a burn-up of 88 MW d kg-1 (equivalent to the burn up of the standard uranium dioxide pelletized fuel) without loss of leak-tightness of the cladding. The feasibility of fabricating IMF of these particular types with plutonium dioxide is considered with a view to in-pile irradiation.

  12. Nuclear reactor with a suspended vessel

    International Nuclear Information System (INIS)

    Lemercier, Guy.

    1977-01-01

    This invention relates to a nuclear reactor with a suspended vessel and applies in particular when this is a fast reactor, the core or active part of the reactor being inside the vessel and immersed under a suitable volume of flowing liquid metal to cool it by extracting the calories released by the nuclear fission in the fuel assemblies forming this core [fr

  13. Bed-levelling experiments with suspended load

    NARCIS (Netherlands)

    Talmon, A.M.; De Graaff, J.

    1991-01-01

    Bed-levelling experiments are conducted in a straight laboratory channel. The experiments involve a significant fraction of suspended sediment transport. The purpose of the experiments is to provide data for modelling of the direction of sediment transport on a transverse sloping alluvial river bed,

  14. The Shape of Breasts Suspended in Liquid

    NARCIS (Netherlands)

    De Kleijn, S.C.; Rensen, W.H.J.

    2007-01-01

    Philips has designed an optical mammography machine. In this machine the breast is suspended into a cup in which the measurements take place. A special fluid is inserted into the cup to prevent the light from going around the breast instead of going through it but this fluid also weakens the signal.

  15. (suspended solids and metals) removal efficiencies

    African Journals Online (AJOL)

    ABSTRACT. Presented in this paper are the results of correlational analyses and logistic regression between metal substances (Cd, Cu,. Pb, Zn), as well as suspended solids removal, and physical pond parameters of 19 stormwater retention pond case studies obtained from the International Stormwater BMP database.

  16. Suspended sediment assessment by combining sound attenuation and backscatter measurements - analytical method and experimental validation

    Science.gov (United States)

    Guerrero, Massimo; Di Federico, Vittorio

    2018-03-01

    The use of acoustic techniques has become common for estimating suspended sediment in water environments. An emitted beam propagates into water producing backscatter and attenuation, which depend on scattering particles concentration and size distribution. Unfortunately, the actual particles size distribution (PSD) may largely affect the accuracy of concentration quantification through the unknown coefficients of backscattering strength, ks2, and normalized attenuation, ζs. This issue was partially solved by applying the multi-frequency approach. Despite this possibility, a relevant scientific and practical question remains regarding the possibility of using acoustic methods to investigate poorly sorted sediment in the spectrum ranging from clay to fine sand. The aim of this study is to investigate the possibility of combining the measurement of sound attenuation and backscatter to determine ζs for the suspended particles and the corresponding concentration. The proposed method is moderately dependent from actual PSD, thus relaxing the need of frequent calibrations to account for changes in ks2 and ζs coefficients. Laboratory tests were conducted under controlled conditions to validate this measurement technique. With respect to existing approaches, the developed method more accurately estimates the concentration of suspended particles ranging from clay to fine sand and, at the same time, gives an indication on their actual PSD.

  17. Biogas production from organic wastes in suspended cell cultures and in biofilms

    International Nuclear Information System (INIS)

    Simenonov, I.; Chorukova, E.; Mamatarkova, V.; Nikolov, L.

    2010-01-01

    The results of a comparative study of two biogas production bioprocess systems are presented. The systems submitted to comparison are based on the suspended cells cultures and the biofilm formed on solid inert support. A comprehensive research concept is formulated and discussed. It includes the main considerations regarding the choice of substrate, bioagent as mixed microbial society, type of bioreactors, regimes of functioning, analytical determinations and method of comparison. The main requirements for efficient experimental activity in comparative investigations are formulated. Their satisfaction can grant correctness of the experimental design and data acquisition. On this basis the key parameter of comparison of the two systems is defined as the specific productivity of the bioprocess systems. Under these conditions series of preliminary experiments are carried out for testing the readiness of experimental set ups for long time stable functioning and monitoring devices capabilities to maintain the bioprocess parameters at the determined intervals. These tests grant continuous incessant experimentation with the investigated bioprocess systems. The results obtained show that biofilm bioprocess systems possess up to two and half time higher specific productivity in comparison with the bioprocess systems with the suspended cells. Some visions about the future developments of comparative research on the influence of additional parameters like the mixer rotation steed, organic loads, and higher values of dilution rates are outlined.

  18. Long-term continuous acoustical suspended-sediment measurements in rivers - Theory, application, bias, and error

    Science.gov (United States)

    Topping, David J.; Wright, Scott A.

    2016-05-04

    It is commonly recognized that suspended-sediment concentrations in rivers can change rapidly in time and independently of water discharge during important sediment‑transporting events (for example, during floods); thus, suspended-sediment measurements at closely spaced time intervals are necessary to characterize suspended‑sediment loads. Because the manual collection of sufficient numbers of suspended-sediment samples required to characterize this variability is often time and cost prohibitive, several “surrogate” techniques have been developed for in situ measurements of properties related to suspended-sediment characteristics (for example, turbidity, laser-diffraction, acoustics). Herein, we present a new physically based method for the simultaneous measurement of suspended-silt-and-clay concentration, suspended-sand concentration, and suspended‑sand median grain size in rivers, using multi‑frequency arrays of single-frequency side‑looking acoustic-Doppler profilers. The method is strongly grounded in the extensive scientific literature on the incoherent scattering of sound by random suspensions of small particles. In particular, the method takes advantage of theory that relates acoustic frequency, acoustic attenuation, acoustic backscatter, suspended-sediment concentration, and suspended-sediment grain-size distribution. We develop the theory and methods, and demonstrate the application of the method at six study sites on the Colorado River and Rio Grande, where large numbers of suspended-sediment samples have been collected concurrently with acoustic attenuation and backscatter measurements over many years. The method produces acoustical measurements of suspended-silt-and-clay and suspended-sand concentration (in units of mg/L), and acoustical measurements of suspended-sand median grain size (in units of mm) that are generally in good to excellent agreement with concurrent physical measurements of these quantities in the river cross sections at

  19. Particle Settling in Low Energy Turbulence

    Science.gov (United States)

    Allen, Rachel; MacVean, Lissa; Tse, Ian; Mazzaro, Laura; Stacey, Mark; Variano, Evan

    2014-11-01

    Particle settling velocities can be altered by turbulence. In turbulence, dense particles may get trapped in convergent flow regions, and falling particles may be swept towards the downward side of turbulent eddies, resulting in enhanced settling velocities. The degree of velocity enhancement may depend on the Stokes number, the Rouse number, and the turbulent Reynolds number. In a homogeneous, isotropic turbulence tank, we tested the effects of particle size and type, suspended sediment concentration, and level of turbulence on the settling velocities of particles typically found in muddy estuaries. Two Acoustic Doppler Velocimeters (ADVs), separated vertically, measured turbulent velocities and suspended sediment concentrations, which yield condition dependent settling velocities, via ∂/á C ñ ∂ t = -∂/∂ z (ws á C ñ + á w ' C ' ñ) . These results are pertinent to fine sediment transport in estuaries, where high concentrations of suspended material are transported and impacted by low energy turbulence.

  20. Suspended-Bed Reactor preliminary design, 233U--232Th cycle. Final report (revised)

    International Nuclear Information System (INIS)

    Karam, R.A.; Alapour, A.; Lee, C.C.

    1977-11-01

    The preliminary design Suspended-Bed Reactor is described. Coated particles about 2 mm in diameter are used as the fuel. The coatings consist of three layers: (1) low density pyrolytic graphite, 70 μ thick, (2) silicon carbide pressure vessel, 30 μ thick, and (3) ZrC layer, 50 μ thick, to protect the pressure vessel from moisture and oxygen. The fuel kernel can be either uranium-thorium dicarbide or metal. The coated particles are suspended by helium gas (coolant) in a cluster of pressurized tubes. The upward flow of helium fluidizes the coated particles. As the flow rate increases, the bed of particles is lifted upward to the core section. The particles are restrained at the upper end of the core by a suitable screen. The overall particle density in the core is just enough for criticality condition. Should the helium flow cease, the bed in the core section will collapse, and the particles will flow downward into the section where the increased physical spacings among the tubes brings about a safe shutdown. By immersing this section of the tubes in a large graphite block to serve as a heat sink, dissipation of decay heat becomes manageable. This eliminates the need for emergency core cooling systems

  1. Characteristics of suspended solids affect bifenthrin toxicity to the calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi.

    Science.gov (United States)

    Parry, Emily; Lesmeister, Sarah; Teh, Swee; Young, Thomas M

    2015-10-01

    Bifenthrin is a pyrethroid pesticide that is highly toxic to aquatic invertebrates. The dissolved concentration is generally thought to be the best predictor of acute toxicity. However, for the filter-feeding calanoid copepods Eurytemora affinis and Pseudodiaptomus forbesi, ingestion of pesticide-bound particles could prove to be another route of exposure. The present study investigated bifenthrin toxicity to E. affinis and P. forbesi in the presence of suspended solids from municipal wastewater effluent and surface water of the San Francisco (CA, USA) Estuary. Suspended solids mitigated the toxicity of total bifenthrin to E. affinis and P. forbesi, but mortality was higher than what would be predicted from dissolved concentrations alone. The results indicate that the toxicity and bioavailability of particle-associated bifenthrin was significantly correlated with counts of 0.5-µm to 2-µm particle sizes. Potential explanations could include direct ingestion of bifenthrin-bound particles, changes in food consumption and feeding behavior, and physical contact with small particles. The complex interactions between pesticides and particles of different types and sizes demonstrate a need for future ecotoxicological studies to investigate the role of particle sizes on aquatic organisms. © 2015 SETAC.

  2. First principles study of inert-gas (helium, neon, and argon) interactions with hydrogen in tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Xiang-Shan [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Hou, Jie [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Li, Xiang-Yan [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Wu, Xuebang, E-mail: xbwu@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Liu, C.S., E-mail: csliu@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P. O. Box 1129, Hefei 230031 (China); Chen, Jun-Ling; Luo, G.-N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2017-04-15

    We have systematically evaluated binding energies of hydrogen with inert-gas (helium, neon, and argon) defects, including interstitial clusters and vacancy-inert-gas complexes, and their stable configurations using first-principles calculations. Our calculations show that these inert-gas defects have large positive binding energies with hydrogen, 0.4–1.1 eV, 0.7–1.0 eV, and 0.6–0.8 eV for helium, neon, and argon, respectively. This indicates that these inert-gas defects can act as traps for hydrogen in tungsten, and impede or interrupt the diffusion of hydrogen in tungsten, which supports the discussion on the influence of inert-gas on hydrogen retention in recent experimental literature. The interaction between these inert-gas defects and hydrogen can be understood by the attractive interaction due to the distortion of the lattice structure induced by inert-gas defects, the intrinsic repulsive interaction between inert-gas atoms and hydrogen, and the hydrogen-hydrogen repelling in tungsten lattice.

  3. Fabrication of inert matrices for heterogeneous transmutation. EFTTRA-T2 (RAS 2) irradiation programme

    International Nuclear Information System (INIS)

    Boshoven, J.G.; Hein, H.; Konings, R.J.M.

    1996-07-01

    This report describes the fabrication of targets containing inert matrices for the heterogeneous transmutation of plutonium and minor actinides. These targets will be irradiated in the EFTTRA-T2 (RAS-2) irradiation programme. The selection, preparation and characterization of the inert matrices and fabrication and loading of the irradiation capsules are discussed. (orig.)

  4. Inerting of a Vented Aircraft Fuel Tank Test Article with Nitrogen-Enriched Air

    National Research Council Canada - National Science Library

    Burns, Michael

    2001-01-01

    ...) required to inert a vented aircraft fuel tank. NEA, generated by a hollow fiber membrane gas separation system, was used to inert a laboratory fuel tank with a single vent on top designed to simulate a transport category airplane fuel tank...

  5. Mechanical behaviour and diffusion of gas during neutron irradiation of actinides in ceramic inert matrices

    NARCIS (Netherlands)

    Neeft, E.A.C.

    2004-01-01

    Fission of actinides from nuclear waste in inert matrices (materials without uranium) can reduce the period in time that nuclear waste is more radiotoxic than uranium ore that is the rock from which ordinary reactor fuel is made. A pioneering study is performed with the inert matrices: MgO, MgAl2O4,

  6. The suspended sentence in French Criminal Law

    Directory of Open Access Journals (Sweden)

    Jovašević Dragan

    2016-01-01

    Full Text Available From the ancient times until today, criminal law has provided different criminal sanctions as measures of social control. These coercive measures are imposed on the criminal offender by the competent court and aimed at limitting the offender's rights and freedoms or depriving the offender of certain rights and freedoms. These sanctions are applied to the natural or legal persons who violate the norms of the legal order and injure or endanger other legal goods that enjoy legal protection. In order to effectively protect social values, criminal legislations in all countries predict a number of criminal sanctions. These are: 1 imprisonment, 2 precautions, 3 safety measures, 4 penalties for juveniles, and 5 sanctions for legal persons. Apart and instead of punishment, warning measures have a significant role in the jurisprudence. Since they emerged in the early 20th century in the system of criminal sanctions, there has been an increase in their application to criminal offenders, especially when it comes to first-time offenders who committed a negligent or accidental criminal act. Warnings are applied in case of crimes that do not have serious consequences, and whose perpetrators are not hardened and incorrigible criminals. All contemporary criminal legislations (including the French legilation provide a warning measure of suspended sentence. Suspended sentence is a conditional stay of execution of sentence of imprisonment for a specified time, provided that the convicted person does not commit another criminal offense and fulfills other obligations. This sanction applies if the following two conditions are fulfilled: a forma! -which is attached to the sentence of imprisonment; and b material -which is the court assessment that the application of this sanction is justified and necessary in a particular case. In many modern criminal legislations, there are two different types of suspended (conditional sentence: 1 ordinary (classical suspended

  7. Universal Virus Adsorption on Inert Particles Utilizing the Coated Latex Adsorption Method (CLAM)

    Science.gov (United States)

    1975-06-30

    DEPARTMENT Dairy -Microbiology Bldg. (605)688-4116 South Dc-frO*- StOn3 lunv&’z Brco<rgs. S D 5 .. May 26, 1976 J. E. Candiff Defense Documentation Center...I . 0. * 54 , P. .0• 15.60 4 x * S 15.bo • r • 16,00 * p1 * 0 .6.20 x + 02 ?C COW ABCTROZI 16.40 0- =* I 9 .( Or 16.60, * p 0 164.0 , . . . . . 0...pneumococcal polysaccharide (28), and to insulin (4) were discovered. Since then, there have been significant progress in the elucidation of the com- plexity of

  8. Wall-to-liquid mass transfer in fluidized beds and vertical transport of inert particles

    Directory of Open Access Journals (Sweden)

    NEVENKA BOSKOVIC–VRAGOLOVIC

    2007-11-01

    Full Text Available The electrochemical oxidation of methanol in NaOH solution was examined on a thin film Pt2Ru3/C electrode. The XRD pattern revealed that the Pt2Ru3 alloy consisted of a solid solution of Ru in Pt and a small amount of Ru or a solid solution of Pt in Ru. It was shown that in alkaline solution, the difference in activity between Pt/C and Pt2Ru3/C is significantly smaller than in acid solution. It is proposed that the reaction follows a quasi bifunctional mechanism. The kinetic parameters indicated that the chemical reaction between adsorbed COad and OHad species could be the rate limiting step.

  9. Calcium Carbonate Formation in Water Distribution Systems and Autogenous Repair of Leaks by Inert Particle Clogging

    OpenAIRE

    Richards, Colin Scott

    2016-01-01

    The formation of calcium carbonate (CaCO3) (i.e. scale) in potable water systems has long been a concern in water treatment and distribution. A literature review reveals that CaCO3 scaling issues are re-emerging due to climate change, temperature increases in hot water systems and lower use of scaling and corrosion inhibitors. Moreover, we have gathered insights that suggest CaCO3 coatings can be beneficial and stop pipeline leaks via self-repair or clogging. Ironically, the actions we are ta...

  10. One-loop contributions to neutral minima in the inert doublet model

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, P.M. [Instituto Superior de Engenharia de Lisboa - ISEL,1959-007 Lisboa (Portugal); Centro de Física Teórica e Computacional - FCUL,Universidade de Lisboa, R. Ernesto de Vasconcelos, 1749-016 Lisboa (Portugal); Świeżewska, Bogumiła [Faculty of Physics, University of Warsaw,Pasteura 5, 02-093 Warsaw (Poland)

    2016-04-15

    The vacuum structure of the inert doublet model is analysed at the one-loop level using the effective potential formalism, to verify the validity of tree-level predictions for the properties of the global minimum. An inert minimum (with massive fermions) and an inert-like minimum (with massless fermions) can coexist at tree level. But the one-loop analysis reveals that the allowed parameter space for the coexistence of more than one minimum is larger than the tree-level expected one. It is also shown that for some choices of parameters, the global minimum found at the one-loop level may be inert (or inert-like), contrary to what the tree-level analysis indicates.

  11. Inert powders alone or in combination with neem oil for controlling Spodoptera eridania and Spodoptera frugiperda (Lepidoptera: Noctuidae larvae

    Directory of Open Access Journals (Sweden)

    Kelly Christiane Constanski Silva

    2016-08-01

    Full Text Available Laboratory studies was carry out to evaluated the potential of inert powders: bentonite, kaolin and diatomaceous earth (DE applied as dust and aqueous suspension alone and associated with neem oil to the control Spodoptera eridania and Spodoptera frugiperda second instar larvae. In dust applications, 100% mortality of S. eridania, at the concentrations of 1.5 and 2.0 grams of bentonite, and 93.3% of S. frugiperda, at the concentration of 2.0 g were observed. DE at the height concentration (2.0 g caused 76.2% mortality of S. eridania and 46.6% of S. frugiperda. Kaolin, in all concentrations, was the only treatment that did not differed from the control for S. eridania but was different, in the high concentration, for S. frugiperda. When the plants were treated, larvae of S. eridania fed in the treatment DE, had an increase of two days in larval period. For the sex ratio, the percentage of males was greater in the treatments with kaolin, for both species. When powders was applied suspended in water separately or combined with neem oil, the best results were observed in combined of the bentonite (10% + neem, with 100% mortality for both species, and kaolin (10% + neem with 78.5% and 95.6% mortality for S. frugiperda and S. eridania, respectively. These treatments were classified as non-additive synergistic.

  12. Swing damped movement of suspended objects

    International Nuclear Information System (INIS)

    Jones, J.F.; Petterson, B.J.; Werner, J.C.

    1990-01-01

    Transportation of large objects such as nuclear waste shipping casks using overhead cranes can induce pendular motion of the object. Residual oscillation from transportation typically must be damped or allowed to decay before the next process can take place. By properly programming the acceleration of the transporting device (e.g., crane) an oscillation damped transport and swing free stop are obtainable. This report reviews the theory associated with formulating such oscillation damped trajectories for a simply suspended object (e.g., simple pendulum). In addition, the use of force servo damping to eliminate initial oscillation of simply suspended objects is discussed. This is often needed to provide a well defined initial state for the system prior to executing an oscillation damped move. Also included are descriptions of experiments using a CIMCORP XR6100 gantry robot and results from these experiments. Finally, sources of error resulting in small residual oscillations are identified and possible solutions presented

  13. Molybdenum-rhenium superconducting suspended nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, Mohsin; Christopher Hudson, David; Russo, Saverio [Centre for Graphene Science, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF (United Kingdom)

    2014-06-09

    Suspended superconducting nanostructures of MoRe 50%/50% by weight are fabricated employing commonly used fabrication steps in micro- and nano-meter scale devices followed by wet-etching with Hydro-fluoric acid of a SiO{sub 2} sacrificial layer. Suspended superconducting channels as narrow as 50 nm and length 3 μm have a critical temperature of ≈6.5 K, which can increase by 0.5 K upon annealing at 400 °C. A detailed study of the dependence of the superconducting critical current and critical temperature upon annealing and in devices with different channel widths reveals that desorption of contaminants is responsible for the improved superconducting properties. These findings pave the way for the development of superconducting electromechanical devices using standard fabrication techniques.

  14. Behavioural response of Phytoseiulus persimilisin inert materials for technical application.

    Science.gov (United States)

    Wendorf, Dennis; Sermann, Helga; Katz, Peter; Lerche, Sandra; Büttner, Carmen

    2009-01-01

    A large scale application of the predatory mite Phytoseiulus persimilis Athias-Henriot for use in the biological control of spider mites in the field requires testing the behaviour of Phytoseiulus persimilis in inert materials, like millet pelts and Vermiculite (1-3 mm). In laboratory studies, the distribution of the individuals in such materials, the time of remaining in the material were proved. To examine the abiotic influences on the time of remaining in the material, the dampness of the materials was varied (0%, 5% and 10%). Moreover, the influence of attitude of materials was tested. The time of emigration from the material was noted for each individual. Emigration from all dry materials was completed 15 minutes at the latest after set up of the mites. The increase of dampness had an obvious effect on the time of remaining in the material. In this respect the material millet pelts showed the most favourable effect with 10% dampness. Increasing attitude of material the mobility of predatory mites will be influenced negatively above 75 cm. Up to 50 cm, mites have not a problem to move in the material and the time of remaining can be prolonged considerably.

  15. Inert annealing of irradiated graphite by inductive heating

    International Nuclear Information System (INIS)

    Botzem, W.; Woerner, J.

    2001-01-01

    Fission neutrons change physical properties of graphite being used in nuclear reactors as moderator and as structural material. The understanding of these effects on an atomic model is expressed by dislocations of carbon atoms within the graphite and the thereby stored energy is known as Wigner Energy. The dismantling of the Pile 1 core may necessitate the thermal treatment of the irradiated but otherwise undamaged graphite. This heat treatment - usually called annealing - initiates the release of stored Wigner Energy in a controlled manner. This energy could otherwise give rise to an increase in temperature under certain conditions during transport or preparation for final storage. In order to prevent such an effect it is intended to anneal the major part of Pile 1 graphite before it is packed into boxes suitable for final disposal. Different heating techniques have been assessed. Inductive heating in an inert atmosphere was selected for installation in the Pile 1 Waste Processing Facility built for the treatment and packaging of the dismantled Pile 1 waste. The graphite blocks will be heated up to 250 deg. C in the annealing ovens, which results in the release of significant amount of the stored energy. External heat sources in a final repository will never heat up the storage boxes to such a temperature. (author)

  16. Investigation of materials for inert electrodes in aluminum electrodeposition cells

    Energy Technology Data Exchange (ETDEWEB)

    Haggerty, J. S.; Sadoway, D. R.

    1987-09-14

    Work was divided into major efforts. The first was the growth and characterization of specimens; the second was Hall cell performance testing. Cathode and anode materials were the subject of investigation. Preparation of specimens included growth of single crystals and synthesis of ultra high purity powders. Special attention was paid to ferrites as they were considered to be the most promising anode materials. Ferrite anode corrosion rates were studied and the electrical conductivities of a set of copper-manganese ferrites were measured. Float Zone, Pendant Drop Cryolite Experiments were undertaken because unsatisfactory choices of candidate materials were being made on the basis of a flawed set of selection criteria applied to an incomplete and sometimes inaccurate data base. This experiment was then constructed to determine whether the apparatus used for float zone crystal growth could be adapted to make a variety of important based melts and their interactions with candidate inert anode materials. The third major topic was Non Consumable Anode (Data Base, Candidate Compositions), driven by our perception that the basis for prior selection of candidate materials was inadequate. Results are presented. 162 refs., 39 figs., 18 tabs.

  17. Network synthesis and parameter optimization for vehicle suspension with inerter

    Directory of Open Access Journals (Sweden)

    Long Chen

    2016-12-01

    Full Text Available In order to design a comfortable-oriented vehicle suspension structure, the network synthesis method was utilized to transfer the problem into solving a timing robust control problem and determine the structure of “inerter–spring–damper” suspension. Bilinear Matrix Inequality was utilized to obtain the timing transfer function. Then, the transfer function of suspension system can be physically implemented by passive elements such as spring, damper, and inerter. By analyzing the sensitivity and quantum genetic algorithm, the optimized parameters of inerter–spring–damper suspension were determined. A quarter-car model was established. The performance of the inerter–spring–damper suspension was verified under random input. The simulation results manifested that the dynamic performance of the proposed suspension was enhanced in contrast with traditional suspension. The root mean square of vehicle body acceleration decreases by 18.9%. The inerter–spring–damper suspension can inhibit the vertical vibration within the frequency of 1–3 Hz effectively and enhance the performance of ride comfort significantly.

  18. Thermal Analysis of Solid Fuels in an Inert Atmosphere

    Science.gov (United States)

    Kijo-Kleczkowska, Agnieszka; Szumera, Magdalena; Środa, Katarzyna

    2017-12-01

    The paper takes the analysis of thermal studies of different types of fuels. It allowed diversification of fuels depending on their composition and origin. Consideration of coal, biomass and waste (coal mule, sewage sludge) as fuel is nowadays an important aspect of energy in our country. It should be emphasized that Poland power engineering is based up to 95% on coal - the primary fuel. Mining industry, forced to deliver power engineering more and better fuel, must however, use a deeper cleaning of coal. This results in a continuous increase waste in the form of mule flotation. The best method of disposing these mule is combustion and co-combustion with other fuels. On the other hand, commonly increasing awareness state of the environment and the need to reduce CO2 emissions energy industry have committed to implement alternative solutions in order to gain power, through, i.a.: development technologies use of biomass, which is one of the most promising renewable energy sources in Poland. The paper presents the results of research TG-DTA fuels made in an inert atmosphere.

  19. Electrodialytic remediation of suspended mine tailings

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Rojo, Adrian; Pino, Denisse

    2008-01-01

    This work shows the laboratory results of nine electrodialytic remediation experiments on copper mine tailings. A newly designed remediation cell, where the solids were kept in suspension by airflow, was tested. The results show that electric current could remove copper from suspended tailings...... efficiency from 1% to 80% compared to experiments with no stirring but with the same operational conditions. This showed the crucial importance of having the solids in suspension and not settled during the remediation....

  20. Exploring the Inert Doublet Model through the dijet plus missing transverse energy channel at the LHC

    Directory of Open Access Journals (Sweden)

    P. Poulose

    2017-02-01

    Full Text Available In this study of the Inert Doublet Model (IDM, we propose that the dijet + missing transverse energy channel at the Large Hadron Collider (LHC will be an effective way of searching for the scalar particles of the IDM. This channel receives contributions from gauge boson fusion, and t-channel production, along with contributions from H+ associated production. We perform the analysis including study of the Standard Model (SM background with assumed systematic uncertainty, and optimise the selection criteria employing suitable cuts on the kinematic variables to maximise the signal significance. We find that with high luminosity option of the LHC, this channel has the potential to probe the IDM in the mass range of up to about 400 GeV, which is not accessible through other leptonic channels. In a scenario with light dark matter of mass about 65 GeV, charged Higgs in the mass range of around 200 GeV provides the best possibility with a signal significance of about 2σ at an integrated luminosity of about 3000 fb−1.

  1. Physicochemical effects on uncontaminated kaolinite due to electrokinetic treatment using inert electrodes.

    Science.gov (United States)

    Liaki, Christina; Rogers, Christopher D F; Boardman, David I

    2008-07-01

    To determine the consequences of applying electrokinetics to clay soils, in terms of mechanisms acting and resulting effects on the clay, tests were conducted in which an electrical gradient was applied across controlled specimens of English China Clay (ECC) using 'inert' electrodes and a 'Reverse Osmosis' water feed to the electrodes (i.e., to mimic electrokinetic stabilisation without the stabiliser added or electrokinetic remediation without the contaminant being present). The specimens in which electromigration was induced over time periods of 3, 7, 14 and 28 days were subsequently tested for Atterberg Limits, undrained shear strength using a hand shear vane, water content, pH, conductivity and zeta potential. Water flowed through the system from anode to cathode and directly affected the undrained shear strength of the clay. Acid and alkali fronts were created around the anode and cathode, respectively, causing changes in the pH, conductivity and zeta potential of the soil. Variations in zeta potential were linked to flocculation and dispersion of the soil particles, thus raising or depressing the Liquid Limit and Plastic Limit, and influencing the undrained shear strength. Initial weakening around the anode and cathode was replaced by a regain of strength at the anode once acidic conditions had been created, while highly alkaline conditions at the cathode induced a marked improvement in strength. A novel means of indicating strength improvement by chemical means, i.e., free from water content effects, is presented to assist in interpretation of the results.

  2. Automatic high-sensitivity control of suspended pollutants in drinking and natural water

    Science.gov (United States)

    Akopov, Edmund I.; Karabegov, M.; Ovanesyan, A.

    1993-11-01

    This article presents a description of the new instrumental method and device for automatic measurement of water turbidity (WT) by means of photoelectron flow ultramicroscope (PFU). The method presents the WT determination by measuring the number concentration (number of particles suspended in 1 cm3 of water under study) using the PFU and demonstrates much higher sensitivity and accuracy in comparison with the usual methods--turbidimetry and nephelometry.

  3. Numerical Modelling of Suspended Transport and Deposition of Highway Deposited Sediments

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben; Bach, Christine

    Good data for calibration and validation of numerical models are of high importance. In the natural environment data can be hard to archive and the stochastic nature have governing influence on the data archived. Hence for modelling of suspended transport and deposition of particles, originating ...... from the highway surfaces, in highway detention ponds, four experiments are carried out. To simplify the complexity of a real pond and for easy control and measurement the sediment transports where carried out in two rectangular channels....

  4. The suspended sentence in German criminal law

    Directory of Open Access Journals (Sweden)

    Jovašević Dragan

    2017-01-01

    Full Text Available From the ancient times until today, criminal law in all countries has provided different criminal sanctions as social control measures. These are court-imposed coercive measures that take away or limit certain rights and freedoms of criminal offenders. Sanctions are applied to natural or legal persons who violate the norms of the legal order and cause damage or endanger other legal goods that enjoy legal protection. In order to effectively protect social values jeopardized by the commission of crime, state legislations prescribe several kinds of criminal sanctions: 1 penalties, 2 precautions, 3 safety measures, 4 penalties for juvenile offenders, and 5 sanctions for legal persons. Penalties are the basic, the oldest and the most important type of criminal sanctions. They are prescribed for the largest number of criminal offences. Imposed instead of or alongside with penalties, warning measures have particularly important role in jurisprudence. Since they were introduced in the system of criminal sanctions in the early 20th century, there has been a notable increase in the application of these measures, particularly in cases involving negligent and accidental offences, and minor offences that do not cause serious consequences, whose perpetrators are not persons with criminal characteristics. Warning measures (suspended sentence are envisaged in all contemporary criminal legislations, including the German legislation. Suspended sentence is a conditional stay of execution of the sentence of imprisonment for a specified time, provided that the convicted person fulfills the imposed obligations and does not commit another criminal offense. Two conditions must be fulfilled for the application of these sanctions: a the formal requirement, which is attached to the sentence of imprisonment; and b the substantive requirement, which implies the court assessment that the application of these sanctions is justified and necessary in a particular case. Many

  5. Suspended sediments from upstream tributaries as the source of downstream river sites

    Science.gov (United States)

    Haddadchi, Arman; Olley, Jon

    2014-05-01

    Understanding the efficiency with which sediment eroded from different sources is transported to the catchment outlet is a key knowledge gap that is critical to our ability to accurately target and prioritise management actions to reduce sediment delivery. Sediment fingerprinting has proven to be an efficient approach to determine the sources of sediment. This study examines the suspended sediment sources from Emu Creek catchment, south eastern Queensland, Australia. In addition to collect suspended sediments from different sites of the streams after the confluence of tributaries and outlet of the catchment, time integrated suspended samples from upper tributaries were used as the source of sediment, instead of using hillslope and channel bank samples. Totally, 35 time-integrated samplers were used to compute the contribution of suspended sediments from different upstream waterways to the downstream sediment sites. Three size fractions of materials including fine sand (63-210 μm), silt (10-63 μm) and fine silt and clay (<10 μm) were used to find the effect of particle size on the contribution of upper sediments as the sources of sediment after river confluences. And then samples were analysed by ICP-MS and -OES to find 41 sediment fingerprints. According to the results of Student's T-distribution mixing model, small creeks in the middle and lower part of the catchment were major source in different size fractions, especially in silt (10-63 μm) samples. Gowrie Creek as covers southern-upstream part of the catchment was a major contributor at the outlet of the catchment in finest size fraction (<10 μm) Large differences between the contributions of suspended sediments from upper tributaries in different size fractions necessitate the selection of appropriate size fraction on sediment tracing in the catchment and also major effect of particle size on the movement and deposition of sediments.

  6. Particle effects on fish gills

    DEFF Research Database (Denmark)

    Lu, Cao; Kania, Per W.; Buchmann, Kurt

    2018-01-01

    Particles composed of inorganic, organic and/or biological materials occur in both natural water bodies and aquaculture facilities. They are expected to affect fish health through a direct chemical, mechanical and biological interaction with gills during ventilation but the nature of the reactions...... and the relative importance of mechanical versus chemical and biological stimulation are unknown. The present work presents an immune gene expression method for evaluation of gill disturbance and sets a baseline for the mechanical influence on fish gills of chemically inert spherical particles. The method may...... be applied to investigate particle impact at different combinations of temperature, fish size, water quality and particle composition. Spherical polystyrene particles (diameters 0.2 μm, 1 μm, 20 μm, 40 μm and 90 μm) were adopted as the particle model and the rainbow trout (Oncorhynchus mykiss) fingerlings...

  7. Co-disposal of industrial wastes to obtain an inert material for environmental reclamation

    Energy Technology Data Exchange (ETDEWEB)

    Polcaro, A.M.; Palams, S.; Mascia, M.; Renoldi, F. [Cagliari Univ., Cagliari (Italy). Dipt. di Ingegneria Chimica e dei Materiali

    2000-02-01

    The present work deals with the treatment of red mud from Eurallumina Bayer plant with gypsum, in order to obtain an inert which might be disposed without risk. The proposed process has particular concern in the local contest in which the Bayer plant is located. The paper compares the characteristics of the effluents obtained leaching with water, beds of either red mud coming from the thickening filters of the Bayer plant (RMF) or from the holding ponds (RMP) or their mixtures with gypsum. The results obtained up to now show that the process is able to lower ph at values near 9, which is stable to further leaching runs. Also the physical characteristics of the resulting material are enhanced, in terms of both particle size distribution and hydraulic permeability. The addition of 10% sandy soil is sufficient to give permeability in the order of 10{sup -4} cm/s, which is typical od sandy soil. [Italian] Il lavoro analizza il trattamento di fango rosso del processo Bayer con gesso allo scopo di ottenere un materiale inerte, che possa essere smaltito senza particolari precauzioni. Il trattamento proposto puo' avere una certa rilevanza nel contesto territoriale in cui l'impianto di produzione e' inserito. In particolare sono state esaminate e confrontate le caratteristiche degli effluenti da prove di liscivazione con acqua di letti costituiti sia da fango prelevato direttamente dai filtri di ispessimento, che da fango prelevato dal bacino di lagunaggio. I risultati mostrano che il processo e' in grado di abbassare il pH del fango ad un valore intorno a 9, che si mantiene stabile alla liscivazione, anche quando la salinita' della massa ha raggiunto valori molto bassi. Il processo consente inoltre di migliorare le caratteristiche fisiche del materiale, sia in termini di granulometria, che si sposta verso le frazioni piu' grosse, che di permeabilita'. Una miscelazione con il 10% di terreno sabbioso e' sufficiente a conferire al

  8. Bulk metal concentrations versus total suspended solids in rivers: Time-invariant & catchment-specific relationships.

    Science.gov (United States)

    Nasrabadi, Touraj; Ruegner, Hermann; Schwientek, Marc; Bennett, Jeremy; Fazel Valipour, Shahin; Grathwohl, Peter

    2018-01-01

    Suspended particles in rivers can act as carriers of potentially bioavailable metal species and are thus an emerging area of interest in river system monitoring. The delineation of bulk metals concentrations in river water into dissolved and particulate components is also important for risk assessment. Linear relationships between bulk metal concentrations in water (CW,tot) and total suspended solids (TSS) in water can be used to easily evaluate dissolved (CW, intercept) and particle-bound metal fluxes (CSUS, slope) in streams (CW,tot = CW + CSUS TSS). In this study, we apply this principle to catchments in Iran (Haraz) and Germany (Ammer, Goldersbach, and Steinlach) that show differences in geology, geochemistry, land use and hydrological characteristics. For each catchment, particle-bound and dissolved concentrations for a suite of metals in water were calculated based on linear regressions of total suspended solids and total metal concentrations. Results were replicable across sampling campaigns in different years and seasons (between 2013 and 2016) and could be reproduced in a laboratory sedimentation experiment. CSUS values generally showed little variability in different catchments and agree well with soil background values for some metals (e.g. lead and nickel) while other metals (e.g. copper) indicate anthropogenic influences. CW was elevated in the Haraz (Iran) catchment, indicating higher bioavailability and potential human and ecological health concerns (where higher values of CSUS/CW are considered as a risk indicator).

  9. UNS S31603 Stainless Steel Tungsten Inert Gas Welds Made with Microparticle and Nanoparticle Oxides

    Directory of Open Access Journals (Sweden)

    Kuang-Hung Tseng

    2014-06-01

    Full Text Available The purpose of this study was to investigate the difference between tungsten inert gas (TIG welding of austenitic stainless steel assisted by microparticle oxides and that assisted by nanoparticle oxides. SiO2 and Al2O3 were used to investigate the effects of the thermal stability and the particle size of the activated compounds on the surface appearance, geometric shape, angular distortion, delta ferrite content and Vickers hardness of the UNS S31603 stainless steel TIG weld. The results show that the use of SiO2 leads to a satisfactory surface appearance compared to that of the TIG weld made with Al2O3. The surface appearance of the TIG weld made with nanoparticle oxide has less flux slag compared with the one made with microparticle oxide of the same type. Compared with microparticle SiO2, the TIG welding with nanoparticle SiO2 has the potential benefits of high joint penetration and less angular distortion in the resulting weldment. The TIG welding with nanoparticle Al2O3 does not result in a significant increase in the penetration or reduction of distortion. The TIG welding with microparticle or nanoparticle SiO2 uses a heat source with higher power density, resulting in a higher ferrite content and hardness of the stainless steel weld metal. In contrast, microparticle or nanoparticle Al2O3 results in no significant difference in metallurgical properties compared to that of the C-TIG weld metal. Compared with oxide particle size, the thermal stability of the oxide plays a significant role in enhancing the joint penetration capability of the weld, for the UNS S31603 stainless steel TIG welds made with activated oxides.

  10. Nanodiamond particles induce IL-8 expression through a transcript stabilization mechanism in human airway epithelial cells

    Science.gov (United States)

    Nanodiamond particles (NDP) prepared by detonational processes have a number of industrial and analytical applications. Previous in vitro studies have reported NDP to be biologically inert with negligible cytotoxicity, implying that they are potentially suitable for biomedical ap...

  11. MECHANISMS OF NANODIAMOND PARTICLE INDUCED IL-8 EXPRESSION IN HUMAN AIRWAY EPITHELIAL CELLS

    Science.gov (United States)

    Nanodiamond particles (NDP) prepared by detonation under confined conditions have a number of industrial and analytical applications. Previous in vitro studies have reported NDP to be biologically inert with negligible cytotoxicity, implying that they are potentially suitable for...

  12. Experimental Study of an On-board Fuel Tank Inerting System

    Science.gov (United States)

    Wu, Fei; Lin, Guiping; Zeng, Yu; Pan, Rui; Sun, Haoyang

    2017-03-01

    A simulated aircraft fuel tank inerting system was established and experiments were conducted to investigate the performance of the system. The system uses hollow fiber membrane which is widely used in aircraft as the air separation device and a simplified 20% scale multi compartment fuel tank as the inerting object. Experiments were carried out to investigate the influences of different operating parameters on the inerting effectiveness of the system, including NEA (nitrogen-enriched air) flow rate, NEA oxygen concentration, NEA distribution, pressure of bleeding air and fuel load of the tank. Results showed that for the multi compartment fuel tank, concentrated flow washing inerting would cause great differences throughout the distribution of oxygen concentration in the fuel tank, and inerting dead zone would exist. The inerting effectiveness was greatly improved and the ullage oxygen concentration of the tank would reduce to 12% successfully when NEA entered three compartments evenly. The time span of a complete inerting process reduced obviously with increasing NEA flow rate and decreasing NEA concentration, but the trend became weaker gradually. However, the reduction of NEA concentration will decrease the utilization efficiency of the bleeding air. In addition, the time span can also be reduced by raising the pressure of bleeding air, which will improve the bleeding air utilization efficiency at the same time. The time span decreases linearly as the fuel load increases.

  13. Development of high frequency tungsten inert gas welding method

    International Nuclear Information System (INIS)

    Morisada, Yoshiaki; Fujii, Hidetoshi; Inagaki, Fuminori; Kamai, Masayoshi

    2013-01-01

    Highlights: ► A new ultrasonic wave TIG welding method was developed. ► The area of the blowholes decreased to less than about 1/8 in the normal TIG weld. ► The number of blowholes decreased with the decreasing frequency. ► The number of blowholes increased when the frequency was less than 15 kHz. ► The microstructure of the weld was refined by ultrasonic wave. -- Abstract: A new welding method, called high frequency tungsten inert gas (TIG) welding, was developed to decrease blowholes in a weld. A1050 aluminum alloy plates (100 mm l × 50 mm w × 5 mm t ) were welded at a frequency from 10 to 40 kHz. An Ar-1% hydrogen mixture was used as the shielding gas to generate blowholes in the experiments. The welding was performed in the horizontal position so that the blowholes can easily be a problem. For comparison, a normal TIG welding was also performed at 60 Hz. After welding, the distribution of the blowholes in the welds was observed in order to evaluate the effect of the sonic wave. The number of blowholes changed with the frequency. A frequency near 15 kHz is the most suitable to decrease the blowholes. Using this new method, the area of blowholes is decreased to less than about 1/8 of the normal TIG weld. This method is much more effective for decreasing the number of blowholes, compared with an ultrasonic wave vibrator which is directly fixed to the sample.

  14. Inertization of galvanic sludges by its incorporation in ceramic products

    Directory of Open Access Journals (Sweden)

    Ferreira, J. M. F.

    1999-04-01

    Full Text Available Sludges produced by the physico-chemical treatments of waste waters generated by electroplating plants were physically and chemically characterised and incorporated in ceramic pastes. The influence of the amount of sludges added to a typical brick composition on the various processing steps and on the green and fired properties was studied. The environmental risks of the incorporation of these sludges rich in heavy metals such as Cr, Pb, Zn, Cu, Ni, etc. were evaluated by performing leaching tests on the fired products. The results showed that sludge contents up to 15 % could be incorporated without affecting significantly the physical characteristics of the ceramic products. Furthermore, a successful inertization of the pollutants was achieved.

    Se han caracterizado desde el punto de vista químico y físico lodos procedentes de las aguas residuales de procesos de galvanizado. Posteriormente se han incorporado a pastas cerámicas, convencionales de la industria ladrillera, estudiándose la influencia de las cantidades añadidas sobre las propiedades de los materiales tanto en verde como en el producto final y durante las distintas etapas de fabricación. Se evaluaron los riesgos medioambientales derivados de la incorporación de los metales pesados, tales como Cr, Pb, Zn, Cu, Ni etc, presentes en los lodos, mediante la realización de ensayos de lixiviado. Los resultados indican que puede incorporarse hasta un 15% en peso de dichos lodos, sin que se produzcan cambios significativos en las propiedades físicas de los materiales cerámicos obtenidos. Se ha obtenido, asimismo, un procedimiento viable de inertización de los agentes contaminantes.

  15. The LISST-SL streamlined isokinetic suspended-sediment profiler

    Science.gov (United States)

    Gray, John R.; Agrawal, Yogesh C.; Pottsmith, H. Charles

    2004-01-01

    The new manually deployed Laser In Situ Scattering Transmissometer-StreamLined profiler (LISST-SL) represents a major technological advance for suspended-sediment measurements in rivers. The LISST-SL is being designed to provide real-time data on sediment concentrations and particle-size distributions. A pressure sensor and current meter provide real-time depth and ambient velocity data, respectively. The velocity data are also used to control pumpage across an internal laser so that the intake velocity is constantly adjusted to match the ambient stream velocity. Such isokinetic withdrawal is necessary for obtaining representative sedimentary measurements in streamflow, and ensures compliance with established practices. The velocity and sediment-concentration data are used to compute fluxes for up to 32 particle-size classes at points, verticals, or in the entire stream cross section. All data are stored internally, as well as transmitted via a 2-wire conductor to the operator using a specially developed communication protocol. The LISST-SL's performance will be measured and compared to published sedimentological accuracy criteria, and a performance summary will be placed on-line.

  16. Self-Assembly of Faceted Colloidal Particles

    NARCIS (Netherlands)

    Gantapara, A.P.

    2015-01-01

    A colloidal dispersion consists of insoluble microscopic particles that are suspended in a solvent. Typically, a colloid is a particle for which at least one of its dimension is within the size range of a nanometer to a micron. Due to collisions with much smaller solvent molecules, colloids perform

  17. Manipulation of magnetic particles in microfluidic volumes

    NARCIS (Netherlands)

    Gao, Y.; Reenen, van A.; Hulsen, M.A.; Jong, de A.M.; Prins, M.W.J.; Toonder, den J.M.J.

    2013-01-01

    This paper reports various ways of field-based manipulation of magnetic colloidal particles to enhance biochemical reactions in lab-on-chip systems [1]. For one (I), we show the possibility to assemble the suspended magnetic micro-particles as tunable re-formable micro-stirrers capable of performing

  18. Statistical examination of particle in a turbulent, non-dilute particle suspension flow experimental measurements

    International Nuclear Information System (INIS)

    Souza, R.C.; Jones, B.G.

    1986-01-01

    An experimental study of particles suspended in fully developed turbulent water flow in a vertical pipe was done. Three series of experiments were conducted to investigate the statistical behaviour of particles in nondilute turbulent suspension flow, for two particle densities and particle sizes, and for several particle volume loadings ranging from 0 to 1 percent. The mean free fall velocity of the particles was determined at these various particle volume loadings, and the phenomenon of cluster formation was observed. The precise volume loading which gives the maximum relative settling velocity was observed to depend on particle density and size. (E.G.) [pt

  19. Turbidity and suspended sediment in the upper Esopus Creek watershed, Ulster County, New York

    Science.gov (United States)

    McHale, Michael R.; Siemion, Jason

    2014-01-01

    Suspended-sediment concentrations (SSCs) and turbidity were measured for 2 to 3 years at 14 monitoring sites throughout the upper Esopus Creek watershed in the Catskill Mountains of New York State. The upper Esopus Creek watershed is part of the New York City water-supply system that supplies water to more than 9 million people every day. Turbidity, caused primarily by high concentrations of inorganic suspended particles, is a potential water-quality concern because it colors the water and can reduce the effectiveness of drinking-water disinfection. The purposes of this study were to quantify concentrations of suspended sediment and turbidity levels, to estimate suspended-sediment loads within the upper Esopus Creek watershed, and to investigate the relations between SSC and turbidity. Samples were collected at four locations along the main channel of Esopus Creek and at all of the principal tributaries. Samples were collected monthly and during storms and were analyzed for SSC and turbidity in the laboratory. Turbidity was also measured every 15 minutes at six of the sampling stations with in situ turbidity probes.

  20. DYNAMIC SUFFICIENCY OF THE MAGNETICALLY SUSPENDED TRAIN

    Directory of Open Access Journals (Sweden)

    V. A. Polyakov

    2013-11-01

    Full Text Available Purpose. The basic criterion of the magnetically suspended train's consumer estimation is a quality of its mechanical motion. This motion is realized in unpredictable conditions and, for purposefulness preservation, should adapt to them. Such adaptation is possible only within the limits of system’s dynamic sufficiency. Sufficiency is understood as presence at system of resources, which allow one to realize its demanded motions without violating actual restrictions. Therefore presence of such resources is a necessary condition of preservation of required purposefulness of train's dynamics, and verification of the mentioned sufficiency is the major component of this dynamic research. Methodology. Methods of the set theory are used in work. Desirable and actual approachability spaces of the train are found. The train is considered dynamically sufficient in zones of the specified spaces overlapping. Findings. Within the limits of the accepted treatment of train's dynamic sufficiency, verification of its presence, as well as a stock (or deficiency of preservations can be executed by the search and the subsequent estimation of such overlapping zones. Operatively (directly during motion it can be realized on the train's ODC with use, for example, of computer mathematics system Mathematica. It possesses extensive opportunities of highly efficient and, at the same time, demanding an expense concerning small resources information manipulation. The efficiency of using of created technique is illustrated on an example of vehicle's acceleration research. Calculation is executed with use of the constructed computer model of interaction of an independent traction electromagnetic subsystem of an artifact with its mechanical subsystem. Originality. The technique of verification of the high-speed magnetically suspended train's dynamic sufficiency is developed. The technique is highly efficient, it provides sufficient presentation and demands an expense of the

  1. Particle Engulfment and Pushing

    Science.gov (United States)

    2001-01-01

    As a liquefied metal solidifies, particles dispersed in the liquid are either pushed ahead of or engulfed by the moving solidification front. Similar effects can be seen when the ground freezes and pushes large particles out of the soil. The Particle Engulfment and Pushing (PEP) experiment, conducted aboard the fourth U.S. Microgravity Payload (USMP-4) mission in 1997, used a glass and plastic beads suspended in a transparent liquid. The liquid was then frozen, trapping or pushing the particles as the solidifying front moved. This simulated the formation of advanced alloys and composite materials. Such studies help scientists to understand how to improve the processes for making advanced materials on Earth. The principal investigator is Dr. Doru Stefanescu of the University of Alabama. This image is from a video downlink.

  2. Comparative Study between Two Schemes of Active-Control-Based Mechatronic Inerter

    Directory of Open Access Journals (Sweden)

    He Lingduo

    2017-01-01

    Full Text Available Based on force-current analogy and velocity-voltage analogy in the theory of electromechanical analogy, the inerter is a device that corresponded to the capacitor completely where conquers the nature restriction of mass, what’s more, it is significant to improve the ratio of the inerter’s inertance to its mass for mechanical networks synthesis. And according to the principle of active-control-based mechatronic inerter, we present two implementation schemes. One was based on linear motor, and the other was based on the ball screw and rotary motor. We introduced the implementation methods and established theoretical model of the two schemes, then compared the ratio of the inerter’s inertance to its mass for the two schemes. Finally, we consider the scheme is better which was based on the ball screw and rotary motor.

  3. For cermet inert anode containing oxide and metal phases useful for the electrolytic production of metals

    Science.gov (United States)

    Ray, Siba P.; Liu, Xinghua; Weirauch, Douglas A.

    2002-01-01

    A cermet inert anode for the electrolytic production of metals such as aluminum is disclosed. The inert anode comprises a ceramic phase including an oxide of Ni, Fe and M, where M is at least one metal selected from Zn, Co, Al, Li, Cu, Ti, V, Cr, Zr, Nb, Ta, W, Mo, Hf and rare earths, preferably Zn and/or Co. Preferred ceramic compositions comprise Fe.sub.2 O.sub.3, NiO and ZnO or CoO. The cermet inert anode also comprises a metal phase such as Cu, Ag, Pd, Pt, Au, Rh, Ru, Ir and/or Os. A preferred metal phase comprises Cu and Ag. The cermet inert anodes may be used in electrolytic reduction cells for the production of commercial purity aluminum as well as other metals.

  4. Inert Reassessment Document for Acetone - CAS No. 67-64-1

    Science.gov (United States)

    Acetone is a highly volatile chemical that is used as an inert ingredient, a solvent/co-solvent, in a variety of pesticide products (including outdoor yard, garden and turf products, and agricultural crop products).

  5. The role of "inert" surface chemistry in marine biofouling prevention.

    Science.gov (United States)

    Rosenhahn, Axel; Schilp, Sören; Kreuzer, Hans Jürgen; Grunze, Michael

    2010-05-07

    The settlement and colonization of marine organisms on submerged man-made surfaces is a major economic problem for many marine industries. The most apparent detrimental effects of biofouling are increased fuel consumption of ships, clogging of membranes and heat exchangers, disabled underwater sensors, and growth of biofoulers in aquaculture systems. The presently common-but environmentally very problematic-way to deal with marine biofouling is to incorporate biocides, which use biocidal products in the surface coatings to kill the colonizing organisms, into the surface coatings. Since the implementation of the International Maritime Organization Treaty on biocides in 2008, the use of tributyltin (TBT) is restricted and thus environmentally benign but effective surface coatings are required. In this short review, we summarize the different strategies which are pursued in academia and industry to better understand the mechanisms of biofouling and to develop strategies which can be used for industrial products. Our focus will be on chemically "inert" model surface coatings, in particular oligo- and poly(ethylene glycol) (OEG and PEG) functionalized surface films. The reasons for choosing this class of chemistry as an example are three-fold: Firstly, experiments on spore settlement on OEG and PEG coatings help to understand the mechanism of non-fouling of highly hydrated interfaces; secondly, these studies defy the common assumption that surface hydrophilicity-as measured by water contact angles-is an unambiguous and predictive tool to determine the fouling behavior on the surface; and thirdly, choosing this system is a good example for "interfacial systems chemistry": it connects the behavior of unicellular marine organisms with the antifouling properties of a hydrated surface coating with structural and electronic properties as derived from ab initio quantum mechanical calculations using the electronic wave functions of oxygen, hydrogen, and carbon. This short

  6. Photoinduced C-C Cross-Coupling of Aryl Chlorides and Inert Arenes

    Directory of Open Access Journals (Sweden)

    Lele Wang

    2016-01-01

    Full Text Available Here we report a facile, efficient, and catalyst-free method to realize C-C cross-coupling of aryl chlorides and inert arenes under UV light irradiation. The aryl radical upon homolytic cleavage of C-Cl bond initiated the nucleophilic substitution reaction with inert arenes to give biaryl products. This mild reaction mode can also be applied to other synthetic reactions, such as the construction of C-N bonds and trifluoromethylated compounds.

  7. Thermodilution versus inert gas rebreathing for estimation of effective pulmonary blood flow

    DEFF Research Database (Denmark)

    Christensen, P; Clemensen, P; Andersen, P K

    2000-01-01

    To compare measurements of the effective pulmonary blood flow (Qep, i.e., nonshunted fraction of cardiac output, Qt) by the inert gas rebreathing (RB) method and the thermodilution (TD) technique in critically ill patients.......To compare measurements of the effective pulmonary blood flow (Qep, i.e., nonshunted fraction of cardiac output, Qt) by the inert gas rebreathing (RB) method and the thermodilution (TD) technique in critically ill patients....

  8. Prediction of suspended-sediment concentrations at selected sites in the Fountain Creek watershed, Colorado, 2008-09

    Science.gov (United States)

    Stogner, Sr., Robert W.; Nelson, Jonathan M.; McDonald, Richard R.; Kinzel, Paul J.; Mau, David P.

    2013-01-01

    In 2008, the U.S. Geological Survey (USGS), in cooperation with Pikes Peak Area Council of Governments, Colorado Water Conservation Board, Colorado Springs City Engineering, and the Lower Arkansas Valley Water Conservancy District, began a small-scale pilot study to evaluate the effectiveness of the use of a computational model of streamflow and suspended-sediment transport for predicting suspended-sediment concentrations and loads in the Fountain Creek watershed in Colorado. Increased erosion and sedimentation damage have been identified by the Fountain Creek Watershed Plan as key problems within the watershed. A recommendation in the Fountain Creek Watershed plan for management of the basin is to establish measurable criteria to determine if progress in reducing erosion and sedimentation damage is being made. The major objective of this study was to test a computational method to predict local suspended-sediment loads at two sites with different geomorphic characteristics in order to evaluate the feasibility of using such an approach to predict local suspended-sediment loads throughout the entire watershed. Detailed topographic surveys, particle-size data, and suspended-sediment samples were collected at two gaged sites: Monument Creek above Woodmen Road at Colorado Springs, Colorado (USGS gage 07103970), and Sand Creek above mouth at Colorado Springs, Colorado (USGS gage 07105600). These data were used to construct three-dimensional computational models of relatively short channel reaches at each site. The streamflow component of these models predicted a spatially distributed field of water-surface elevation, water velocity, and bed shear stress for a range of stream discharges. Using the model predictions, along with measured particle sizes, the sediment-transport component of the model predicted the suspended-sediment concentration throughout the reach of interest. These computed concentrations were used with predicted flow patterns and channel morphology to

  9. Suspended particulate matter flocculation in a natural tidal wetland located in the San Francisco Estuary

    Science.gov (United States)

    Saraceno, J.; Bergamaschi, B. A.; Wright, S. A.; Boss, E.; Downing, B. D.; Fleck, J.; Ganju, N. K.

    2011-12-01

    Suspended mineral and algal particles together comprise suspended particulate matter (SPM). The SPM size distribution influences the quantity and color of light penetration and the adsorption and transport of contaminants such as pesticides and metals. It is widely known that interaction with wetlands alters the size distribution and quality of particles through local primary production, differential settling and particle aggregation, however, our understanding of how tidal wetland processes affect SPM quantity and size spectra has been hampered by the difficulty of directly observing these parameters at tidal time scales. To evaluate how SPM concentration and size varied over tidal time scales and to better understand the relationship between organic matter and sediment characteristics, simultaneous measurements of dissolved organic matter, SPM concentration and organic content as well as in situ surrogates of particle concentration (turbidity, particulate attenuation, volume concentration) and particle size (laser diffraction) were carried out with measurements of current velocity (acoustic Doppler velocity meter) in the main channel of Brown's Island located in the western San Joaquin/Sacramento River Delta, CA. The study period coincided with high estuary sediment levels following a significant precipitation runoff event. In the Brown Island wetland, particle concentration and size dynamics were tied to variations in water level and velocity. Turbidity and attenuation covaried with the volume concentration of particles smaller than 33 um, which on average represented greater than 50% of particle population by volume. On average, these SPM concentration surrogates were three times higher in flood water than in ebb water; consistent with a loss of fine particles on the island. Following the highest flood tide, the decrease in fine particles was coincident with an increase in the concentration of particles larger than 130 um; a finding consistent with particle

  10. Comparability of river suspended-sediment sampling and laboratory analysis methods

    Science.gov (United States)

    Groten, Joel T.; Johnson, Gregory D.

    2018-03-06

    Accurate measurements of suspended sediment, a leading water-quality impairment in many Minnesota rivers, are important for managing and protecting water resources; however, water-quality standards for suspended sediment in Minnesota are based on grab field sampling and total suspended solids (TSS) laboratory analysis methods that have underrepresented concentrations of suspended sediment in rivers compared to U.S. Geological Survey equal-width-increment or equal-discharge-increment (EWDI) field sampling and suspended sediment concentration (SSC) laboratory analysis methods. Because of this underrepresentation, the U.S. Geological Survey, in collaboration with the Minnesota Pollution Control Agency, collected concurrent grab and EWDI samples at eight sites to compare results obtained using different combinations of field sampling and laboratory analysis methods.Study results determined that grab field sampling and TSS laboratory analysis results were biased substantially low compared to EWDI sampling and SSC laboratory analysis results, respectively. Differences in both field sampling and laboratory analysis methods caused grab and TSS methods to be biased substantially low. The difference in laboratory analysis methods was slightly greater than field sampling methods.Sand-sized particles had a strong effect on the comparability of the field sampling and laboratory analysis methods. These results indicated that grab field sampling and TSS laboratory analysis methods fail to capture most of the sand being transported by the stream. The results indicate there is less of a difference among samples collected with grab field sampling and analyzed for TSS and concentration of fines in SSC. Even though differences are present, the presence of strong correlations between SSC and TSS concentrations provides the opportunity to develop site specific relations to address transport processes not captured by grab field sampling and TSS laboratory analysis methods.

  11. Number size distribution of fine and ultrafine fume particles from various welding processes.

    Science.gov (United States)

    Brand, Peter; Lenz, Klaus; Reisgen, Uwe; Kraus, Thomas

    2013-04-01

    Studies in the field of environmental epidemiology indicate that for the adverse effect of inhaled particles not only particle mass is crucial but also particle size is. Ultrafine particles with diameters below 100 nm are of special interest since these particles have high surface area to mass ratio and have properties which differ from those of larger particles. In this paper, particle size distributions of various welding and joining techniques were measured close to the welding process using a fast mobility particle sizer (FMPS). It turned out that welding processes with high mass emission rates (manual metal arc welding, metal active gas welding, metal inert gas welding, metal inert gas soldering, and laser welding) show mainly agglomerated particles with diameters above 100 nm and only few particles in the size range below 50 nm (10 to 15%). Welding processes with low mass emission rates (tungsten inert gas welding and resistance spot welding) emit predominantly ultrafine particles with diameters well below 100 nm. This finding can be explained by considerably faster agglomeration processes in welding processes with high mass emission rates. Although mass emission is low for tungsten inert gas welding and resistance spot welding, due to the low particle size of the fume, these processes cannot be labeled as toxicologically irrelevant and should be further investigated.

  12. Experimental Investigations of the Weathering of Suspended Sediment by Alpine Glacial Meltwater

    Science.gov (United States)

    Brown, Giles H.; Tranter, M.; Sharp, M. J.

    1996-04-01

    The magnitude and processes of solute acquisition by dilute meltwater in contact with suspended sediment in the channelized component of the hydroglacial system have been investigated through a suite of controlled laboratory experiments. Constrained by field data from Haut Glacier d'Arolla, Valais, Switzerland the effects of the water to rock ratio, particle size, crushing, repeated wetting and the availability of protons on the rate of solute acquisition are demonstrated. These free-drift experiments suggest that the rock flour is extremely geochemically reactive and that dilute quickflow waters are certain to acquire solute from suspended sediment. These data have important implications for hydrological interpretations based on the solute content of glacial meltwater, mixing model calculations, geochemical denudation rates and solute provenance studies.

  13. Deformation and fracture behavior of simulated particle gels

    NARCIS (Netherlands)

    Rzepiela, A.A.

    2003-01-01

    In this PhD project rheological properties of model particle gels are investigated using Brownian Dynamics (BD) simulations. Particle gels are systems of colloidal particles that form weakly bonded percolating networks interpenetrated by a suspending fluid. They are characterized as

  14. The acceleration of solid particles subjected to cavitation nucleation

    DEFF Research Database (Denmark)

    Borkent, B.M.; Arora, M.; Ohl, C.-D.

    2008-01-01

    The cavity -particle dynamics at cavitation inception on the surface of spherical particles suspended in water and exposed to a strong tensile stress wave is experimentally studied with high-speed photography. Particles, which serve as nucleation sites for cavitation bubbles, are set into a fast...

  15. Comparing peracetic acid and hypochlorite for disinfection of combined sewer overflows: Effects of suspended-solids and pH.

    Science.gov (United States)

    McFadden, M; Loconsole, J; Schockling, A J; Nerenberg, R; Pavissich, J P

    2017-12-01

    Peracetic acid (PAA) is an alternative disinfectant that may be effective for combined sewer overflow (CSO) disinfection, but little is known about the effect of particle size on PAA disinfection efficiency. In this work, PAA and hypochlorite were compared as disinfectants, with a focus on the effect of wastewater particles. Inactivation experiments were conducted on suspended cultures of Escherichia coli and wastewater suspended solids. Tested size fractions included particle diameters disinfection efficiency decreased with increasing solids size. However, solids size had little effect on PAA disinfection. The PAA disinfection efficiency decreased at pH values above 7.5. Live/dead staining revealed that PAA disinfection leaves most cells in a viable but non-culturable condition. Fourier transform infrared spectroscopy (FTIR) analyses suggests that PAA and hypochlorite may inactivate E. coli bacteria by similar mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations

    Science.gov (United States)

    Voichick, Nicholas; Topping, David; Griffiths, Ronald

    2018-01-01

    Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers and erosion in catchments, (4) to manage siltation of water reservoirs, and (5) to establish connections with aquatic biological properties, such as primary production and predator–prey interactions. Turbidity is typically measured with an optical probe that detects light scattered from particles in the water. Probes have defined upper limits of the range of turbidity that they can measure. The general assumption is that when turbidity exceeds this upper limit, the values of turbidity will be constant, i.e., the probe is pegged; however, this assumption is not necessarily valid. In rivers with limited variation in the physical properties of the suspended sediment, at lower suspended-sediment concentrations, an increase in suspended-sediment concentration will cause a linear increase in turbidity. When the suspended-sediment concentration in these rivers is high, turbidity levels can exceed the upper measurement limit of an optical probe and record a constant pegged value. However, at extremely high suspended-sediment concentrations, optical turbidity probes do not necessarily stay pegged at a constant value. Data from the Colorado River in Grand Canyon, Arizona, USA, and a laboratory experiment both demonstrate that when turbidity exceeds instrument-pegged conditions, increasing suspended-sediment concentration (and thus increasing turbidity) may cause optical probes to record decreasing false turbidity values that appear to be within the valid measurement range of the probe. Therefore, under high-turbidity conditions, other surrogate measurements of turbidity (e.g., acoustic-attenuation measurements or suspended-sediment samples

  17. The Association of Cryptosporidium parvum With Suspended Sediments: Implications for Transport in Surface Waters

    Science.gov (United States)

    Searcy, K. E.; Packman, A. I.; Atwill, E. R.; Harter, T.

    2003-12-01

    Understanding the transport and fate of microorganisms in surface waters is of vital concern in protecting the integrity and safety of municipal water supply systems. The human pathogen Cryptosporidium parvum is a particular public health interest, as it is ubiquitous in the surface waters of the United States, it can persist for long periods in the environment, and it is difficult to disinfect in water treatment plants. Due to its small size (5 um), low specific gravity (1.05 g/cm3), and negative surface charge, C. parvum oocysts are generally considered to move through watersheds from their source to drinking water reservoirs with little attenuation. However, the transport of the oocysts in surface waters may be mediated by interactions with suspended sediments. Batch experiments were conducted to determine the extent of C. parvum oocyst attachment to several inorganic and organic sediments under varying water chemical conditions, and settling column experiments were performed to demonstrate how these associations influence the effective settling velocity of C. parvum oocysts. Results from these experiments showed that C. parvum oocysts do associate with inorganic and organic sediments and often settle at the rate of the suspended sediment. The size and surface charge of the host suspended sediment influenced the extent of oocyst attachment as oocysts preferentially associated with particles greater than 3 um, and fewer oocysts associated with particles having a highly negative surface charge. Background water chemical conditions including ionic strength, ion composition, and pH did not have a significant effect on oocyst attachment to suspended sediments.

  18. Organics and Suspended Solids Removal from Hospital

    Directory of Open Access Journals (Sweden)

    Fakhri Y. Hmood

    2013-05-01

    Full Text Available The Sequencing Batch Reactor (SBR method is used for treating samples of waste water taken from hospitals in Mosul. Many run periods are used (6-24 hours for             6 months. It is found that the organics and suspended solids removal increase with increasing the period of run, it is in the range ( 96-82 % and ( 100-95 % respectively, while the pH values are nearly neutral (7.05 to 7.5.     BOD5 and SS concentrations of the effluent are within the limits of Iraqi standards,  40:30 mg/l respectively. Hence, SBR method could be used for treating hospitals, small factories and some  residential sectors waste waters.  

  19. Suspended-sediment transport from the Green-Duwamish River to the Lower Duwamish Waterway, Seattle, Washington, 2013–17

    Science.gov (United States)

    Senter, Craig A.; Conn, Kathleen E.; Black, Robert W.; Peterson, Norman; Vanderpool-Kimura, Ann M.; Foreman, James R.

    2018-02-28

    The Green-Duwamish River transports watershed-derived sediment to the Lower Duwamish Waterway Superfund site near Seattle, Washington. Understanding the amount of sediment transported by the river is essential to the bed sediment cleanup process. Turbidity, discharge, suspended-sediment concentration (SSC), and particle-size data were collected by the U.S. Geological Survey (USGS) from February 2013 to January 2017 at the Duwamish River, Washington, within the tidal influence at river kilometer 16.7 (USGS streamgage 12113390; Duwamish River at Golf Course at Tukwila, WA). This report quantifies the timing and magnitude of suspended-sediment transported in the Duwamish River. Regression models were developed between SSC and turbidity and SSC and discharge to estimate 15- minute SSC. Suspended-sediment loads were calculated from the computed SSC and time-series discharge data for every 15-minute interval during the study period. The 2014–16 average annual suspended-sediment load computed was 117,246 tons (106,364 metric tons), of which 73.5 percent or (86,191 tons; 78,191 metric tons) was fine particle (less than 0.0625 millimeter in diameter) suspended sediment. The seasonality of this site is apparent when you divide the year into "wet" (October 16– April 15) and "dry" (April 16–October 15) seasons. Most (97 percent) of the annual suspended sediment was transported during the wet season, when brief periods of intense precipitation from storms, large releases from the Howard Hanson Dam, or a combination of both were much more frequent.

  20. Storage filters upland suspended sediment signals delivered from watersheds

    Science.gov (United States)

    Pizzuto, James E.; Keeler, Jeremy; Skalak, Katherine; Karwan, Diana

    2017-01-01

    Climate change, tectonics, and humans create long- and short-term temporal variations in the supply of suspended sediment to rivers. These signals, generated in upland erosional areas, are filtered by alluvial storage before reaching the basin outlet. We quantified this filter using a random walk model driven by sediment budget data, a power-law distributed probability density function (PDF) to determine how long sediment remains stored, and a constant downstream drift velocity during transport of 157 km/yr. For 25 km of transport, few particles are stored, and the median travel time is 0.2 yr. For 1000 km of transport, nearly all particles are stored, and the median travel time is 2.5 m.y. Both travel-time distributions are power laws. The 1000 km travel-time distribution was then used to filter sinusoidal input signals with periods of 10 yr and 104 yr. The 10 yr signal is delayed by 12.5 times its input period, damped by a factor of 380, and is output as a power law. The 104 yr signal is delayed by 0.15 times its input period, damped by a factor of 3, and the output signal retains its sinusoidal input form (but with a power-law “tail”). Delivery time scales for these two signals are controlled by storage; in-channel transport time is insignificant, and low-frequency signals are transmitted with greater fidelity than high-frequency signals. These signal modifications are essential to consider when evaluating watershed restoration schemes designed to control sediment loading, and where source-area geomorphic processes are inferred from the geologic record.

  1. Energy values of suspended detritus in Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnakumari, L.; Royan, J.P.; Sumitra-Vijayaraghavan

    Energy content of suspended detritus was determined in Andaman Sea waters during April-May 1988. The caloric content of suspended detritus ranged from 987 to 7040 cal. per gram dry wt with an average value of 5530 cal. per gram dry wt. The results...

  2. Dynamic model of movement of mine suspended monorail

    Directory of Open Access Journals (Sweden)

    Viktor GUTAREVYCH

    2014-03-01

    Full Text Available In the article we have developed the dynamic model of interaction of rolling stock during the movement, on the suspended monorail, taking into account the side-sway. We have received the motion equations, carried out their analysis and determined the own oscillation frequencies of rolling stock of suspended monorail.

  3. A thermodynamics model for morphology prediction of aluminum nano crystals fabricated by the inert gas condensation method

    Science.gov (United States)

    Wen, Yu; Xia, Dehong

    2018-03-01

    The purpose of this study is to provide scientific guidance for the morphological control of nanoparticle synthesis using the gas phase method. A universal thermodynamics model is developed to predict the morphology of nanoparticles fabricated using the inert gas condensation method. By using this model, the morphologies of aluminum nanocrystals are predicted under various preparation conditions. There are two types of energy that jointly determine the formation of nanoparticle morphology—Gibbs free energy for nanoparticles and energy variation during the process. The results show that energy variation dominates morphology formation when the cooling rate is less than 2 × 1011 K s-1 in the aluminum nanocrystal production process. At the beginning of the nanoparticle growth, the most stable morphology is predicted to be spherical, but the energetically preferred morphology becomes cubic as the particle grows. The turning point in the particle size at which spherical morphology is no longer the most stable morphology is exhibited as a function of pressure in a condensation chamber for different cooling rates. In this paper, we focus on the need for morphology prediction based on preparation conditions. It is concluded that nanoparticles with various morphologies could be obtained by adjusting the cooling rate and pressure in the condensation chamber.

  4. Fast inertial particle manipulation in oscillating flows

    Science.gov (United States)

    Thameem, Raqeeb; Rallabandi, Bhargav; Hilgenfeldt, Sascha

    2017-05-01

    It is demonstrated that micron-sized particles suspended in fluid near oscillating interfaces experience strong inertial displacements above and beyond the fluid streaming. Experiments with oscillating bubbles show rectified particle lift over extraordinarily short (millisecond) times. A quantitative model on both the oscillatory and the steady time scales describes the particle displacement relative to the fluid motion. The formalism yields analytical predictions confirming the observed scaling behavior with particle size and experimental control parameters. It applies to a large class of oscillatory flows with applications from particle trapping to size sorting.

  5. Measurements of hydrogen concentration in liquid sodium by using an inert gas carrier method

    International Nuclear Information System (INIS)

    Funada, T.; Nihei, I.; Yuhara, S.; Nakasuji, T.

    1979-01-01

    A technique was developed to measure the hydrogen level in liquid sodium using an inert gas carrier method. Hydrogen was extracted into an inert gas from sodium through a thin nickel membrane in the form of a helically wound tube. The amount of hydrogen in the inert gas was analyzed by gas chromatography. The present method is unique in that it can be used over the wide range of sodium temperatures (150 to 700 0 C) and has no problems associated with vacuum systems. The partial pressure of hydrogen in sodium was determined as a function of cold-trap temperature (T/sub c/). Sieverts' constant (K/sub s/) was determined as a function of sodium temperature (T). From Sieverts' constant, the solubility of hydrogen in sodium is calculated. It was found that other impurities in sodium, such as (O) and (OH), have little effect on the hydrogen pressure in the sodium loop

  6. Ethanol Dehydration by Evaporation and Diffusion in an Inert Gas Layer

    Energy Technology Data Exchange (ETDEWEB)

    In-Sick, Chung; Kyu-Min, Song [Korea Advanced Institute of Science and Technology, Taejeon (Korea, Republic of); Won-Hi, Hong; Ho-Nam, Chang [Korea Advanced Institute of Science and Technology, Taejeon (Korea, Republic of)

    1994-08-01

    Ethanol dehydration of azeotropic mixture was performed by using diffusion distillation apparatus consisting of a wetted-wall column with two concentric tubes. Ethanol-water mixtures evaporated below the boiling point was separated during the diffusion through the gap filled with an inert gas. As the temperature difference between evaporation part and condensation part was increased, the total flux increased but the selectivity decreased. The effect of the annular width on the selectivity was not significant but the total flux was decreased with decreases in the annular width. Inert gas has an effect on the diffusivity of evaporated gas components. The total flux in case of helium as inert gas was larger than that in case of air but the selectivity in case of using helium was lower. (author). 14 refs. 1 tab. 12 figs.

  7. Thermodynamic stability and kinetic inertness of a Gd-DTPA bisamide complex grafted onto gold nanoparticles.

    Science.gov (United States)

    Mogilireddy, Vijetha; Déchamps-Olivier, Isabelle; Alric, Christophe; Laurent, Gautier; Laurent, Sophie; Vander Elst, Luce; Muller, Robert; Bazzi, Rana; Roux, Stéphane; Tillement, Olivier; Chuburu, Françoise

    2015-01-01

    Gold nanoparticles coated by gadolinium (III) chelates (Au@DTDTPA) where DTDTPA is a dithiolated bisamide derivative of diethylenetriamine-N,N,N',N'',N''-pentaacetic acid (DTPA), constituted contrast agents for both X-ray computed tomography and magnetic resonance imaging. In an MRI context, highly stable Gd(3+) complexes are needed for in vivo applications. Thus, knowledge of the thermodynamic stability and kinetic inertness of these chelates, when grafted onto gold nanoparticles, is crucial since bisamide DTPA chelates are usually less suited for Gd(3+) coordination than DTPA. Therefore, these parameters were evaluated by means of potentiometric titrations and relaxivity measurements. The results showed that, when the chelates were grafted onto the nanoparticle, not only their thermodynamic stability but also their kinetic inertness were improved. These positive effects were correlated to the chelate packing at the nanoparticle surface that stabilized the corresponding Gd(3+) complexes and greatly enhanced their kinetic inertness. Copyright © 2014 John Wiley & Sons, Ltd.

  8. Nanotoxicity of Inert Materials: The Case of Gold, Silver and Iron.

    Science.gov (United States)

    Umair, Muhammad; Javed, Ibrahim; Rehman, Mubashar; Madni, Asadullah; Javeed, Aqeel; Ghafoor, Aamir; Ashraf, Muhammad

    2016-01-01

    Nanotechnology has opened a new horizon of research in various fields including applied physics, chemistry, electronics, optics, robotics, biotechnology and medicine. In the biomedical field, nanomaterials have shown remarkable potential as theranostic agents. Materials which are considered inert are often used in nanomedicine owning to their nontoxic profile. At nanoscale, these inert materials have shown unique properties that differ from bulk and dissolved counterparts. In the case of metals, this unique behavior not only imparts paramount advantages but also confers toxicity due to their unwanted interaction with different cellular processes. In the literature, the toxicity of nanoparticles made from inert materials has been investigated and many of these have revealed toxic potential under specific conditions. The surge to understand underlying mechanism of toxicity has increased and different means have been employed to overcome toxicity problems associated with these agents. In this review, we have focused nanoparticles of three inert metallic materials i.e. gold, silver and iron as these are regarded as biologically inert in the bulk and dissolved form. These materials have gained wider research interest and studies indicating the toxicity of these materials are also emerging. Oxidative stress, physical binding and interference with intracellular signaling are the major role player in nanotoxicity and their predominance is highly dependent upon size, surface coating and administered dose of nanoparticles. Current strategies to overcome toxicity have also been reviewed in the light of recent literature. The authors also suggested that uniform testing standards and well-designed studies are needed to evaluate nanotoxicity of these materials that are otherwise considered as inert. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

  9. Performance of suspended and attached growth MBR systems in treating high strength synthetic wastewater.

    Science.gov (United States)

    Jamal Khan, S; Ilyas, Shazia; Javid, Sadaf; Visvanathan, C; Jegatheesan, V

    2011-05-01

    The performance of laboratory-scale attached growth (AG) and suspended growth (SG) membrane bioreactors (MBRs) was evaluated in treating synthetic wastewater simulating high strength domestic wastewater. This study investigated the influence of sponge suspended carriers in AG-MBR system, occupying 15% reactor volume, on the removal of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP), and compared it to that of SG-MBR. Results showed that the removal efficiencies of COD, TN and TP in AG-MBR were 98%, 89% and 58%, respectively as compared to 98%, 74% and 38%, respectively in SG-MBR. Improved TN removal in AG-MBR systems was primarily based on simultaneous nitrification and denitrification (SND) process. These results infer that the presence of small bio-particles having higher microbial activity and the growth of complex biomass captured within the suspended sponge carriers resulted in improved TN and TP removal in AG-MBR. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Ultrasensitive mass sensing with nonlinear optics in a doubly clamped suspended carbon nanotube resonator

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hua-Jun; Zhu, Ka-Di [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai 2 00240 (China)

    2013-12-07

    Nanomechanical resonator makes itself as an ideal system for ultrasensitive mass sensing due to its ultralow mass and high vibrational frequency. The mass sensing principle is due to the linear relationship of the frequency-shift and mass-variation. In this work, we will propose a nonlinear optical mass sensor based on a doubly clamped suspended carbon nanotube resonator in all-optical domain. The masses of external particles (such as nitric oxide molecules) landing onto the surface of carbon nanotube can be determined directly and accurately via using the nonlinear optical spectroscopy. This mass sensing proposed here may provide a nonlinear optical measurement technique in quantum measurements and environmental science.

  11. A steam inerting system for hydrogen disposal for the Vandenberg Shuttle

    Science.gov (United States)

    Belknap, Stuart B.

    1988-01-01

    A two-year feasibility and test program to solve the problem of unburned confined hydrogen at the Vandenberg Space Launch Complex Six (SLC-6) during Space Shuttle Main Engine (SSME) firings is discussed. A novel steam inerting design was selected for development. Available sound suppression water is superheated to flash to steam at the duct entrance. Testing, analysis, and design during 1987 showed that the steam inerting system (SIS) solves the problem and meets other flight-critical system requirements. The SIS design is complete and available for installation at SLC-6 to support shuttle or derivative vehicles.

  12. Inert dusts and their effects on the poultry red mite (Dermanyssus gallinae)

    DEFF Research Database (Denmark)

    Kilpinen, Ole; Steenberg, Tove

    2009-01-01

    commonly applied alternative control methods for poultry red mite in Europe. This development has occurred despite a lack of knowledge of the efficacy of the different types of inert dusts and how this is affected by environmental parameters, e.g. the high relative humidity found in poultry houses....... In this laboratory study the efficacy of different commercial inert dust products against D. gallinae is compared. All tested compounds killed mites, but there was a clear ranking of efficacy (measured as weight loss after 24 h and as time until 50% mortality), particularly at 75% relative humidity (RH). At 85% RH...

  13. Plastic Trash goes Biohybrid"-Rapid and Selective Functionalization of Inert Plastic Surfaces with Biomolecules

    DEFF Research Database (Denmark)

    Schiller, Stefan M; Kambhampati, Dev; Stengel, Gudrun

    2010-01-01

    The covalent functionalization of "inert" polymers such as polypropylene with biomolecules for biocompatible or biosensor surfaces is challenging. Here we present a powerful approach to covalently modify "inert" macromolecular surfaces with biomacromolecules reusing old plastic material. A special...... emphasis was placed on easily accessible materials and a process which is easy, fast, efficient, cheap, and reliable. "Plastic trash" (lids from Eppendorf® pipet tip containers) was used as a polymer substrate to demonstrate the use/reuse of commercial packing material to covalently modify this material...

  14. Zirconia based inert matrix fuel: fabrication concepts and feasibility studies

    International Nuclear Information System (INIS)

    Ingold, F.; Burghartz, M.; Ledergerber, G.

    1999-01-01

    The internal gelation process has traditionally been applied to fabricate standard fuel based on uranium, typically UO2 and MOX. To meet the recent aim to destroy plutonium in the most effective way, a uranium free fuel was evaluated. The fuel development programme at PSI has been redirected toward a fuel based on zirconium oxide or a mixture of zirconia and a conducting material to form ceramic/metal (CERMET) or ceramic/ceramic (CERCER) combinations. A feasibility study was carried out to demonstrate that microspheres based on zirconia and spinel can be fabricated with the required properties. The gelation parameters were investigated to optimise compositions of the starting solutions. Studies to fabricate a composite material (from zirconia and spinel) are ongoing. If the zirconia/spinel ratio is chosen appropriately, the low thermal conductivity of pure zirconia can be compensated by the higher thermal conductivity of spinel. Another solution to offset the low thermal conductivity of zirconia is the development of a CERMET, which consists of fine particles bearing plutonium in a cubic zirconia lattice dispersed in a metallic matrix. The fabrication of such a CERMET is also being studied. (author)

  15. Methods of and system for swing damping movement of suspended objects

    Science.gov (United States)

    Jones, J.F.; Petterson, B.J.; Strip, D.R.

    1991-03-05

    A payload suspended from a gantry is swing damped in accordance with a control algorithm based on the periodic motion of the suspended mass or by servoing on the forces induced by the suspended mass. 13 figures.

  16. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution — ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  17. Increasing precision of turbidity-based suspended sediment concentration and load estimates.

    Science.gov (United States)

    Jastram, John D; Zipper, Carl E; Zelazny, Lucian W; Hyer, Kenneth E

    2010-01-01

    Turbidity is an effective tool for estimating and monitoring suspended sediments in aquatic systems. Turbidity can be measured in situ remotely and at fine temporal scales as a surrogate for suspended sediment concentration (SSC), providing opportunity for a more complete record of SSC than is possible with physical sampling approaches. However, there is variability in turbidity-based SSC estimates and in sediment loadings calculated from those estimates. This study investigated the potential to improve turbidity-based SSC, and by extension the resulting sediment loading estimates, by incorporating hydrologic variables that can be monitored remotely and continuously (typically 15-min intervals) into the SSC estimation procedure. On the Roanoke River in southwestern Virginia, hydrologic stage, turbidity, and other water-quality parameters were monitored with in situ instrumentation; suspended sediments were sampled manually during elevated turbidity events; samples were analyzed for SSC and physical properties including particle-size distribution and organic C content; and rainfall was quantified by geologic source area. The study identified physical properties of the suspended-sediment samples that contribute to SSC estimation variance and hydrologic variables that explained variability of those physical properties. Results indicated that the inclusion of any of the measured physical properties in turbidity-based SSC estimation models reduces unexplained variance. Further, the use of hydrologic variables to represent these physical properties, along with turbidity, resulted in a model, relying solely on data collected remotely and continuously, that estimated SSC with less variance than a conventional turbidity-based univariate model, allowing a more precise estimate of sediment loading, Modeling results are consistent with known mechanisms governing sediment transport in hydrologic systems.

  18. The Effect of Suspended Sediment Transport and Deposition on Streambed Clogging Under Losing and Gaining Flow Conditions

    Science.gov (United States)

    Fox, A.; Packman, A. I.; Preziosi-Ribero, A.; Li, A.; Arnon, S.

    2017-12-01

    Sediment transport and deposition in streams can affect streambed hydraulic characteristics due to clogging, reduce water fluxes through the hyporheic zone, and thus expected to affect biogeochemical processes. Processes affecting deposition of suspended particles were systematically studied under various overlying velocities but without taking into account the interactions with groundwater. This is despite the fact that the interaction with groundwater were shown to play an important role in deposition patterns of fine sediments in field studies. The objective of this study was to evaluate the effect of losing and gaining fluxes on suspended sediment depositional patterns and on hyporheic exchange fluxes. Experiments were conducted in a laboratory flume system (640 cm long and 30 cm wide) that has a capacity to enforce losing or gaining flow conditions. The flume was packed with homogenous sand, while suspended sediment deposition was evaluated by adding kaolinite particles to the water and following the deposition rate by particle disappearance from the bulk water. Consecutive additions of kaolinite were done, while hyporheic exchange fluxes were evaluated by conducting NaCl tracer experiments between each kaolinite additions. Furthermore, dye injections were used to visualize the flow patterns in the streambed using time-lapse photography through the transparent sidewalls of the flume. Hyporheic exchange and particle tracking simulations were done to assess the results of particle deposition and feedbacks between hyporheic flow, particle transport, and streambed clogging. Experimental results showed that the deposition of clay decreases with increasing amount of clay concentration in the sediment. Hyporheic exchange flux decreases linearly with increasing amount of clay added to the system and the region of active hyporheic exchange was confined to the upper part of the sediment. Understanding the particle deposition mechanisms under losing and gaining flow

  19. Estimation of suspended sediment concentration by acoustic ...

    African Journals Online (AJOL)

    concentration of sediments such as glass spheres or sand. However, the acoustic properties of natural sediments vary and depend on many parameters such as particle size, shape, mineralogy and distribution of those parameters in sample. Therefore, this study was conducted to determine the possibility of soil sediment ...

  20. Separating particles from a liquid

    International Nuclear Information System (INIS)

    Leslie, C.M.; Watson, J.H.P.; Williams, J.A.

    1980-01-01

    An apparatus for separating particles suspended in a liquid from the liquid, is described, in which a flow of the liquid is passed through a filter bed of ferromagnetic bodies which acts as a coarse filter to trap the larger particles in the flow. The filter bed is arranged within a truncated core between the poles of an electromagnet. To cleanse the bed and flush out the trapped particles a wash liquid is passed through the bed and the electromagnet is energised to levitate the bed to allow the wash liquid to remove the particles. The liquid flow from the coarse filter can be passed to a high gradient magnetic separator at which remaining small particles in the flow are filtered magnetically. (U.K.)

  1. Modification of Structure and Tribological Properties of the Surface Layer of Metal-Ceramic Composite under Electron Irradiation in the Plasmas of Inert Gases

    Science.gov (United States)

    Ovcharenko, V. E.; Ivanov, K. V.; Mohovikov, A. A.; Yu, B.; Xu, Yu; Zhong, L.

    2018-01-01

    Metal-ceramic composites are the main materials for high-load parts in tribomechanical systems. Modern approaches to extend the operation life of tribomechanical systems are based on increasing the strength and tribological properties of the surface layer having 100 to 200 microns in depth. The essential improvement of the properties occurs when high dispersed structure is formed in the surface layer using high-energy processing. As a result of the dispersed structure formation the more uniform distribution of elastic stresses takes place under mechanical or thermal action, the energy of stress concentrators emergence significantly increases and the probability of internal defects formation reduces. The promising method to form the dispersed structure in the surface layer is pulse electron irradiation in the plasmas of inert gases combining electron irradiation and ion bombardment in one process. The present work reports upon the effect of pulse electron irradiation in plasmas of different inert gases with different atomic mass and ionization energy on the structure and tribological properties of the surface layer of TiC/(Ni-Cr) metal-ceramic composite with the volume ratio of the component being 50:50. It is experimentally shown that high-dispersed heterophase structure with a fraction of nanosized particles is formed during the irradiation. Electron microscopy study reveals that refining of the initial coarse TiC particles occurs via their dissolution in the molten metal binder followed by the precipitation of secondary fine particles in the interparticle layers of the binder. The depth of modified layer and the fraction of nanosized particles increase when the atomic number of the plasma gas increases and ionization energy decreases. The wear resistance of metal-ceramic composite improves in accordance to the formation of nanocrystalline structure in the surface layer.

  2. Introduction to suspended-sediment sampling

    Science.gov (United States)

    Nolan, K. Michael; Gray, John R.; Glysson, G. Douglas

    2005-01-01

    Knowledge of the amount and timing of sediment transport in streams is important to those directly or indirectly responsible for developing and managing water and land resources. Such data are often used to judge the health of watershed and the success or failure of activities designed to mitigate adverse impacts of sediment on streams and stream habitats. This training class presents an introduction to methods currently used by the U.S. Geological Survey (USGS) to sample suspended-sediment concentrations in streams. The presentation is narrated, but you control the pace of the presentation. If the computer you are using can view 'MPEG' videos you will be able to take advantage of videos interspersed in the presentation. A test, found at the end of the presentation, can be taken to assess how well you understood the training material. The class, which is registered as class SW4416 with the National Training Center of the USGS, should take two or three hours to complete. In order to use the presentation provided via this Web page, you will need to download a large disc images (linked below) and 'burn' it to a blank CD-ROM using a CD-ROM recorder on your computer. The presentation will only run on a Windows-based personal computer (PC). The presentation was developed using Macromedia Director MX 20041 and is contained in the file 'SIR05-5077.exe' which should autolaunch. If it does not, the presentation can be started by double-clicking on the file name. A sound card and speakers are necessary to take advantage of narrations that accompany the presentation. Text of narrations is provided, if you are unable to listen to narrations. Instructions for installing and running the presentation are included in the file 'Tutorial.htm', which is on the CD. 1 Registered Trademark: Macromedia Incorporated

  3. Method of enhanced lithiation of doped silicon carbide via high temperature annealing in an inert atmosphere

    Science.gov (United States)

    Hersam, Mark C.; Lipson, Albert L.; Bandyopadhyay, Sudeshna; Karmel, Hunter J; Bedzyk, Michael J

    2014-05-27

    A method for enhancing the lithium-ion capacity of a doped silicon carbide is disclosed. The method utilizes heat treating the silicon carbide in an inert atmosphere. Also disclosed are anodes for lithium-ion batteries prepared by the method.

  4. Defined media and inert supports : their potential as solid-state fermentation production systems

    NARCIS (Netherlands)

    Ooijkaas, L.P.; Weber, F.J.; Buitelaar, R.M.; Tramper, J.; Rinzema, A.

    2000-01-01

    Solid-state fermentation (SSF) using inert supports impregnated with chemically defined liquid media has several potential applications in both scientific studies and in the industrial production of high-value products, such as metabolites, biological control agents and enzymes. As a result of its

  5. Does the Addition of Inert Gases at Constant Volume and Temperature Affect Chemical Equilibrium?

    Science.gov (United States)

    Paiva, Joao C. M.; Goncalves, Jorge; Fonseca, Susana

    2008-01-01

    In this article we examine three approaches, leading to different conclusions, for answering the question "Does the addition of inert gases at constant volume and temperature modify the state of equilibrium?" In the first approach, the answer is yes as a result of a common students' alternative conception; the second approach, valid only for ideal…

  6. Relationships among ventilation-perfusion distribution, multiple inert gas methodology and metabolic blood-gas tensions.

    Science.gov (United States)

    Lee, A S; Patterson, R W; Kaufman, R D

    1987-12-01

    The retention equations upon which the Multiple Inert Gas Method is based are derived from basic principles using elementary algebra. It is shown that widely disparate distributions produce indistinguishable sets of retentions. The limits of resolution of perfused compartments in the VA/Q distribution obtainable by the use of the multiple inert gas method are explored mathematically, and determined to be at most shunt and two alveolar compartments ("tripartite" distribution). Every continuous distribution studied produced retentions indistinguishable from those of its unique "matching" tripartite distribution. When a distribution is minimally specified, it is unique. Any additional specification (increased resolution--more compartments) of the distribution results in the existence of an infinitude of possible distributions characterized by indistinguishable sets of retention values. No further increase in resolution results from the use of more tracers. When sets of retention values were extracted from published multiple inert gas method continuous distributions, and compared with the published "measured" retention sets, substantial differences were found. This illustrates the potential errors incurred in the practical, in vivo application of the multiple inert gas method. In preliminary studies, the tripartite distribution could be determined with at least comparable accuracy by blood-gas (oxygen, carbon dioxide) measurements.

  7. Dynamics of soluble and inert pollutant concentrations in linear and deterministic systems with time varying parameters

    International Nuclear Information System (INIS)

    Meltzer, M.

    1977-04-01

    The tracer theory in steady and non-steady systems is presented. The unsteady system was applied in the study of the concentration dynamics of the National Water Carrier in Israel. A method that uses Bromine 82 for the investigation of the transfer time distribution and of the dynamics of inert matter concentration in the system is desribed. (B.G.)

  8. Chromium liquid waste inertization in an inorganic alkali activated matrix: Leaching and NMR multinuclear approach

    International Nuclear Information System (INIS)

    Ponzoni, Chiara; Lancellotti, Isabella; Barbieri, Luisa; Spinella, Alberto; Saladino, Maria Luisa; Martino, Delia Chillura; Caponetti, Eugenio; Armetta, Francesco; Leonelli, Cristina

    2015-01-01

    Highlights: • Inertization of chromium liquid waste in aluminosilicate matrix. • Water less inertization technique exploiting the waste water content. • Liquid waste inertization without drying step. • Long term stabilization study through leaching test. • SEM analysis and 29 Si and 27 Al MAS NMR in relation with long curing time. - Abstract: A class of inorganic binders, also known as geopolymers, can be obtained by alkali activation of aluminosilicate powders at room temperature. The process is affected by many parameters (curing time, curing temperature, relative humidity etc.) and leads to a resistant matrix usable for inertization of hazardous waste. In this study an industrial liquid waste containing a high amount of chromium (≈2.3 wt%) in the form of metalorganic salts is inertized into a metakaolin based geopolymer matrix. One of the innovative aspects is the exploitation of the water contained in the waste for the geopolymerization process. This avoided any drying treatment, a common step in the management of liquid hazardous waste. The evolution of the process - from the precursor dissolution to the final geopolymer matrix hardening - of different geopolymers containing a waste amount ranging from 3 to 20% wt and their capability to inertize chromium cations were studied by: i) the leaching tests, according to the EN 12,457 regulation, at different curing times (15, 28, 90 and 540 days) monitoring releases of chromium ions (Cr(III) and Cr(VI)) and the cations constituting the aluminosilicate matrix (Na, Si, Al); ii) the humidity variation for different curing times (15 and 540 days); iii) SEM characterization at different curing times (28 and 540 days); iv) the trend of the solution conductivity and pH during the leaching test; v) the characterization of the short-range ordering in terms of T−O−T bonds (where T is Al or Si) by 29 Si and 27 Al solid state magic-angle spinning nuclear magnetic resonance (ss MAS NMR) for geopolymers

  9. Chromium liquid waste inertization in an inorganic alkali activated matrix: Leaching and NMR multinuclear approach

    Energy Technology Data Exchange (ETDEWEB)

    Ponzoni, Chiara, E-mail: chiara.ponzoni@unimore.it [University of Modena and Reggio Emilia, Department of Engineering “Enzo Ferrari”, Modena (Italy); Lancellotti, Isabella; Barbieri, Luisa [University of Modena and Reggio Emilia, Department of Engineering “Enzo Ferrari”, Modena (Italy); Spinella, Alberto; Saladino, Maria Luisa [University of Palermo CGA-UniNetLab, Palermo (Italy); Martino, Delia Chillura [University of Palermo, Department STEBICEF, Palermo (Italy); Caponetti, Eugenio [University of Palermo CGA-UniNetLab, Palermo (Italy); University of Palermo, Department STEBICEF, Palermo (Italy); Armetta, Francesco [University of Palermo, Department STEBICEF, Palermo (Italy); Leonelli, Cristina [University of Modena and Reggio Emilia, Department of Engineering “Enzo Ferrari”, Modena (Italy)

    2015-04-09

    Highlights: • Inertization of chromium liquid waste in aluminosilicate matrix. • Water less inertization technique exploiting the waste water content. • Liquid waste inertization without drying step. • Long term stabilization study through leaching test. • SEM analysis and {sup 29}Si and {sup 27}Al MAS NMR in relation with long curing time. - Abstract: A class of inorganic binders, also known as geopolymers, can be obtained by alkali activation of aluminosilicate powders at room temperature. The process is affected by many parameters (curing time, curing temperature, relative humidity etc.) and leads to a resistant matrix usable for inertization of hazardous waste. In this study an industrial liquid waste containing a high amount of chromium (≈2.3 wt%) in the form of metalorganic salts is inertized into a metakaolin based geopolymer matrix. One of the innovative aspects is the exploitation of the water contained in the waste for the geopolymerization process. This avoided any drying treatment, a common step in the management of liquid hazardous waste. The evolution of the process - from the precursor dissolution to the final geopolymer matrix hardening - of different geopolymers containing a waste amount ranging from 3 to 20% wt and their capability to inertize chromium cations were studied by: i) the leaching tests, according to the EN 12,457 regulation, at different curing times (15, 28, 90 and 540 days) monitoring releases of chromium ions (Cr(III) and Cr(VI)) and the cations constituting the aluminosilicate matrix (Na, Si, Al); ii) the humidity variation for different curing times (15 and 540 days); iii) SEM characterization at different curing times (28 and 540 days); iv) the trend of the solution conductivity and pH during the leaching test; v) the characterization of the short-range ordering in terms of T−O−T bonds (where T is Al or Si) by {sup 29}Si and {sup 27}Al solid state magic-angle spinning nuclear magnetic resonance (ss MAS NMR) for

  10. Air pollution in Aleppo city, gases,suspended particulates

    International Nuclear Information System (INIS)

    Othman, I.; Sabra, Sh.; Al-Kharfan, K.

    1994-06-01

    Total suspended particulates measured by using High Volume Air Sampler. The Co and O 3 were measured during weekday and weekend. The concentration of all pollutants at city center are higher than other measured areas. (author). 10 figs., 10 tabs

  11. Improved Methods for Correlating Turbidity and Suspended Solids for Monitoring

    National Research Council Canada - National Science Library

    2000-01-01

    This technical note describes techniques normally used to measure turbidity and suspended solids in waters, how the two parameters relate to each other and to various environmental impacts, and why...

  12. Self-suspended permanent magnetic FePt ferrofluids

    KAUST Repository

    Dallas, Panagiotis; Kelarakis, Antonios; Sahore, Ritu; DiSalvo, Francis J.; Livi, Sebastien; Giannelis, Emmanuel P.

    2013-01-01

    on the surface of L10 FePt nanoparticles. In contrast, all types of ferrofluids previously reported employ either volatile solvents as the suspending media or superparamagnetic iron oxide nanoparticles (that lacks permanent magnetization) as the inorganic

  13. Novel Resuscitation from Lethal Hemorrhage - Suspended Animation for Delayed Resuscitation

    National Research Council Canada - National Science Library

    Safar, Peter

    2002-01-01

    .... We have conceived and documented "suspended animation for delayed resuscitation" with the use of hypothermic saline flush into the aorta within the first 5 minute of no blood flow, using novel...

  14. Evaluation of the suspending properties of Abizia zygia gum on ...

    African Journals Online (AJOL)

    Purpose: Some excipients are currently available for the formulation of pharmaceutical suspensions. ... Method: The suspending properties of Albizia zygia gum (family ... Characterization tests were carried out on purified Albizia zygia gum.

  15. Suspended sediment apportionment in a South-Korean mountain catchment

    Science.gov (United States)

    Birkholz, Axel; Meusburger, Katrin; Park, Ji-Hyung; Alewell, Christine

    2016-04-01

    Due to the rapid agricultural expansion and intensification during the last decades in South-Korea, large areas of hill slope forests were transformed to paddies and vegetable fields. The intensive agriculture and the easily erodible soils in our catchment are a major reason for the increased erosion causing suspended sediments to infiltrate into the close drinking water reservoir. The drinking water reservoir Lake Soyang provides water supply for over ten million people in Seoul. Landscape managers need to know the exact origin of these sediments before they can create landscape amelioration schemes. We applied a compound-specific stable isotope (CSSI) approach (Alewell et al., 2015) to apportion the sources of the suspended sediments between forest and agricultural soil contribution to the suspended sediments in a different catchment and applied the same approach to identify and quantify the different sources of the suspended sediments in the river(s) contributing to Lake Soyang. We sampled eight soil sites within the catchment considering the different landuse types forest, rice paddies, maize and vegetables. Suspended sediments were sampled at three outlets of the different sub-catchments. Soils and suspended sediments are analysed for bulk carbon and nitrogen isotopes, compound-specific carbon isotopes of plant-wax derived long-chain fatty acids and long-chain n-alkanes. Fatty acid and alkane isotopes are then used in mixing calculations and the mixing model software IsoSource to find out the contribution of the different source soils to the suspended sediments. We present first data of the source soils and the suspended sediments. C. Alewell, A. Birkholz, K. Meusburger, Y. Schindler-Wildhaber, L. Mabit, 2015. Sediment source attribution from multiple land use systems with CSIA. Biogeosciences Discuss. 12: 14245-14269.

  16. Numerical analysis on hydrogen stratification and post-inerting of hydrogen risk

    International Nuclear Information System (INIS)

    Peng, Cheng; Tong, Lili; Cao, Xuewu

    2016-01-01

    Highlights: • A three-dimensional computational model was built and the applicability was discussed. • The formation of helium stratification was further studied. • Three influencing factors on the post-inerting of hydrogen risk were analyzed. - Abstract: In the case of severe accidents, the risk of hydrogen explosion threatens the integrity of the nuclear reactor containment. According to nuclear regulations, hydrogen control is required to ensure the safe operation of the nuclear reactor. In this study, the method of Computational Fluid Dynamics (CFD) has been applied to analyze process of hydrogen stratification and the post-inerting of hydrogen risk in the Large-Scale Gas Mixing Facility. A three-dimensional computational model was built and the applicability of different turbulence models was discussed. The result shows that the helium concentration calculated by the standard k–ε turbulence model is closest to the experiment data. Through analyzing the formation of helium stratification at different injection velocities, it is found that when the injection mass flow is constant and the injection velocity of helium increases, the mixture of helium and air is enhanced while there is rarely influence on the formation of helium stratification. In addition, the influences of mass flow rate, injection location and direction and inert gas on the post-inerting of hydrogen risk have been analyzed and the results are as follows: with the increasing of mass flow rate, the mitigation effect of nitrogen on hydrogen risk will be further improved; there is an obvious local difference between the mitigation effects of nitrogen on hydrogen risk in different injection directions and locations; when the inert gas is injected at the same mass flow rate, the mitigation effect of steam on hydrogen risk is better than that of nitrogen. This study can provide technical support for the mitigation of hydrogen risk in the small LWR containment.

  17. Process for separation of inert fission gases for waste gas of a reprocessing plant for nuclear fuel

    International Nuclear Information System (INIS)

    Schnez, H.

    1980-01-01

    The inert fission gases Kr and Xe released in the resolver and other waste gases are taken to an acid regeneration plant. Part of the inert fission gases is separated by compression, cooling and filtering and deposited. The other part flows back to the resolver as flushing gas so that a flushing gas circuit is formed, which prevents explosive gas mixtures occurring. (DG) [de

  18. Evaluation of the air quality regarding total suspended particles and heavy metals (Pb, Cd, Ni, Cu, Cr) in the Hermosillo city, Sonora, Mexico, during a yearly period; Evaluacion de la calidad del aire respecto de particulas suspendidas totales y metales pesados (Pb, Cd, Ni, Cu, Cr) en la Ciudad de Hermosillo, Sonora, Mexico, durante un periodo anual

    Energy Technology Data Exchange (ETDEWEB)

    Cruz C, M. E.; Quintero N, M. [Universidad Autonoma de Baja California, Instituto de Ingenieria, Campus Mexicali, Calle de la Normal s/n, y Blvd. Benito Juarez, Col. Insurgentes Este, Mexicali, Baja California (Mexico); Gomez A, A.; Varela S, J., E-mail: martincruzcampas@hotmail.com [Universidad de Sonora, Departamento de Ingenieria Quimica y Metalurgia, Blvd. Rosales y Luis Ensina s/n, Edificio 5B, Col. Centro, 83000 Hermosillo, Sonora (Mexico)

    2013-07-01

    In the present study, the air quality of the city of Hermosillo, Sonora, Mexico was assessed considering total suspended particulates (tsp) and heavy metals (Pb, Cd, Ni, Cu, Cr) from June 2001 through May 2002 in three monitoring sites Centro (Mazon), Nor este (CESUES) and Noroeste (CBTIS). The filter-samples used for that purpose were provided by the Air Quality Evaluation and Improvement Program (PEMCA) of the municipality of Hermosillo. The sampling method was based on high volume sampling frequency set every 6 days with non-simultaneous sampling among the three sampling sites. Filters were dissolved for metal determination by acidic-extraction, and then analyzed by flame atomic absorption spectrophotometry. Results indicate that tsp concentrations at Centro and Noroeste sites were frequently higher than the maximum daily permissible level (260 {mu}g/m{sup 3}), while in the three sites the annual average was higher than the maximum annual permissible level (75 {mu}g/m{sup 3}) both established in the standard NOM-024-Ssa-1993 (Ssa 1994a). According to the Air Quality Standard Index (US EPA 1992a), used in Mexico by Air Quality Metropolitan Index (IMECA) the results indicate that the air quality in the city of Hermosillo regarding tsp was placed between no satisfactory and poor. In regard to heavy metals (Pb, Cd, Ni, Cu, Cr), concentrations detected were below the maximum permissible levels and/or criteria taking into account the standard NOM-026-Ssa-1993 (Ssa 1994b), the Who criterion (2000), the European Union criterion (Cec 2003), and the European Environmental Agency criteria (EEA 2004). Such findings would mean that airborne metals are of no concern; however, air quality is still classified as no satisfactory due to high particulate matter concentrations. Keeping air quality parameters monitoring is recommended in order to get extensive data for use in risk studies of air quality and health (morbidity/mortality), as well as topographic conditions

  19. New spectrometer for charged particles

    International Nuclear Information System (INIS)

    Wajsfelner, Rene

    1970-02-01

    This thesis is devoted to the study and development of an electrostatic spectrometer which is not only more accurate for the determination of size distributions of electrically charged radio-active atmospheric aerosols, but which can also be used for measuring the grain-size distribution of any cloud of particles which will previously have been charged according to a known, reproducible law. An experimental study has been made of the development of this precipitator and also of its calibration. The electrical charge on spherical polystyrene latex particles suspended in air by atomization has been studied; a theoretical explanation of these results is put forward. (author) [fr

  20. Comparison of three inert markers in measuring apparent nutrient digestibility of juvenile abalone under different culture condition and temperature regimes

    Science.gov (United States)

    Nur, K. U.; Adams, L.; Stone, D.; Savva, N.; Adams, M.

    2018-03-01

    A comparative research using three inert markers, chromic oxide, yttrium and ytterbium to measure the apparent nutrient digestibility of experimental feed in juvenile Hybrid abalone (Haliotis rubra X H. laevigata) and Greenlip abalone (H.laevigata) revealed that apparent digestibility of crude protein (ADCP) measured using yttrium and ytterbium in hybrid abalone were significantly different across the treatments. Protein digestibility measured in experimental tanks was higher than those measured in indoor and outdoor commercial tanks, regardless of inert marker used. Chromic oxide led to overestimated ADCP compared to when measured using yttrium and ytterbium. There were no significant interactions between temperature and inert markers when measuring ADCP and apparent digestibility of gross energy (ADGE). However, there was a significant difference of ADCP amongst inert markers when measured in greenlip abalone cultured at two temperatures. While measurements of ADge calculated using three inert markers shared the same value.

  1. factors affecting particle retention in thermal field-flow fractionation

    African Journals Online (AJOL)

    In this paper, we report a range of factors which affect the retention of colloidal particles in thermal field-flow fractionation (ThFFF). These results are observed among different sizes of polystyrene (PS) latex particles suspended in both aqueous and nonaqueous liquid carriers and very low density lipoproteins in a phosphate ...

  2. Apparatus and method for handling magnetic particles in a fluid

    Science.gov (United States)

    Holman, David A.; Grate, Jay W.; Bruckner-Lea, Cynthia J.

    2000-01-01

    The present invention is an apparatus and method for handling magnetic particles suspended in a fluid, relying upon the known features of a magnetic flux conductor that is permeable thereby permitting the magnetic particles and fluid to flow therethrough; and a controllable magnetic field for the handling. The present invention is an improvement wherein the magnetic flux conductor is a monolithic porous foam.

  3. Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures

    International Nuclear Information System (INIS)

    Addai, Emmanuel Kwasi; Gabel, Dieter; Krause, Ulrich

    2016-01-01

    Highlights: • Ignition sensitivity of a highly flammable dust decreases upon addition of inert dust. • Minimum ignition temperature of a highly flammable dust increases when inert concentration increase. • Minimum ignition energy of a highly flammable dust increases when inert concentration increase. • The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. - Abstract: The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%.

  4. Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Addai, Emmanuel Kwasi, E-mail: emmanueladdai41@yahoo.com; Gabel, Dieter; Krause, Ulrich

    2016-04-15

    Highlights: • Ignition sensitivity of a highly flammable dust decreases upon addition of inert dust. • Minimum ignition temperature of a highly flammable dust increases when inert concentration increase. • Minimum ignition energy of a highly flammable dust increases when inert concentration increase. • The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. - Abstract: The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%.

  5. Superconducting lead particles produced by chemical techniques

    Science.gov (United States)

    Fariss, T. L.; Nixon, W. E.; Bucelot, T. J.; Deaver, B. S., Jr.; Mitchell, J. W.

    1982-09-01

    The superconductivity of extremely small lead particles has been studied as a function of size, surface condition, and connectivity using chemical techniques to produce particles of well-controlled size and shape suspended in insulating media. Approximately monodisperse suspensions of equiaxed, rod, and lath-shaped particles of lead halides and other lead compounds suspended in gelatin, polyacrylamide, polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, and hydroxyethyl cellulose have been produced. These particles have been reduced to pseudomorphs of lead in the liquid phase or the suspensions have been coated on substrates and dried before reduction. Reducing solutions containing aminoiminomethanesulfinic acid are effective with particles of lead halides, lead phosphate, lead sulfate, and lead tartrate. Suspensions of smaller discrete lead particles have also been produced by direct reduction of solutions of soluble lead salts containing suitable polymers, chelating, and stabilizing agents. Dispersions with mean particle dimensions between 3 nm and 5 μm, and a narrow size-frequency distribution, have been produced. The superconductivity of the particles has been characterized by measurements of the magnetization as a function of temperature and magnetic field. The larger particles have a transition temperature of 7.2 K, the same as bulk lead; however, for particles of characteristic dimensions less than 20 nm, the transition temperature is lower by ˜0.1 K.

  6. Superconducting lead particles produced by chemical techniques

    International Nuclear Information System (INIS)

    Fariss, T.L.; Nixon, W.E.; Bucelot, T.J.; Deaver, B.S. Jr.; Mitchell, J.W.

    1982-01-01

    The superconductivity of extremely small lead particles has been studied as a function of size, surface condition, and connectivity using chemical techniques to produce particles of well-controlled size and shape suspended in insulating media. Approximately monodisperse suspensions of equiaxed, rod, and lath-shaped particles of lead halides and other lead compounds suspended in gelatin, polyacrylamide, polyvinylpyrrolidone, polyvinyl alcohol, methyl cellulose, and hydroxyethyl cellulose have been produced. These particles have been reduced to pseudomorphs of lead in the liquid phase or the suspensions have been coated on substrates and dried before reduction. Reducing solutions containing aminoiminomethanesulfinic acid are effective with particles of lead halides, lead phosphate, lead sulfate, and lead tartrate. Suspensions of smaller discrete lead particles have also been produced by direct reduction of solutions of soluble lead salts containing suitable polymers, chelating, and stabilizing agents. Dispersions with mean particle dimensions between 3 nm and 5 μm, and a narrow size-frequency distribution, have been produced. The superconductivity of the particles has been characterized by measurements of the magnetization as a function of temperature and magnetic field. The larger particles have a transition temperature of 7.2 K, the same as bulk lead; however, for particles of characteristic dimensions less than 20 nm, the transition temperature is lower by approx.0.1 K

  7. Understanding the ice nucleation characteristics of feldspars suspended in solution

    Science.gov (United States)

    Kumar, Anand; Marcolli, Claudia; Kaufmann, Lukas; Krieger, Ulrich; Peter, Thomas

    2017-04-01

    Freezing of liquid droplets and subsequent ice crystal growth affects optical properties of clouds and precipitation. Field measurements show that ice formation in cumulus and stratiform clouds begins at temperatures much warmer than those associated with homogeneous ice nucleation in pure water, which is ascribed to heterogeneous ice nucleation occurring on the foreign surfaces of ice nuclei (IN). Various insoluble particles such as mineral dust, soot, metallic particles, volcanic ash, or primary biological particles have been suggested as IN. Among these the suitability of mineral dusts is best established. The ice nucleation ability of mineral dust particles may be modified when secondary organic or inorganic substances are accumulating on the dust during atmospheric transport. If the coating is completely wetting the mineral dust particles, heterogeneous ice nucleation occurs in immersion mode also below 100 % RH. A previous study by Zobrist et al. (2008) Arizona test dust, silver iodide, nonadecanol and silicon dioxide suspensions in various solutes showed reduced ice nucleation efficiency (in immersion mode) of the particles. Though it is still quite unclear how surface modifications and coatings influence the ice nucleation activity of the components present in natural dust particles at a microphysical scale. To improve our understanding how solute and mineral dust particle surface interaction, we run freezing experiments using a differential scanning calorimeter (DSC) with microcline, sanidine, plagioclase, kaolinite and quartz particles suspended in pure water and solutions containing ammonia, ammonium bisulfate, ammonium sulfate, ammonium chloride, ammonium nitrate, potassium chloride, potassium sulfate, sodium sulfate and sulfuric acid. Methodology Suspensions of mineral dust samples (2 - 5 wt%) are prepared in water with varying solute concentrations (0 - 15 wt%). 20 vol% of this suspension plus 80 vol% of a mixture of 95 wt% mineral oil (Aldrich

  8. An at-grade stabilization structure impact on runoff and suspended sediment

    Science.gov (United States)

    Minks, Kyle R.; Lowery, Birl; Madison, Fred W.; Ruark, Matthew; Frame, Dennis R.; Stuntebeck, Todd D.; Komiskey, Matthew J.

    2012-01-01

    In recent years, agricultural runoff has received more attention as a major contributor to surface water pollution. This is especially true for the unglaciated area of Wisconsin, given this area's steep topography, which makes it highly susceptible to runoff and soil loss. We evaluated the ability of an at-grade stabilization structure (AGSS), designed as a conservation practice to reduce the amount of overland runoff and suspended sediment transported to the surface waters of an agricultural watershed. Eight years of storm and baseflow data collected by the US Geological Survey–Wisconsin Water Science Center on a farm in west central Wisconsin were analyzed for changes in precipitation, storm runoff volume, and suspended sediment concentration before and after installation of an AGSS. The agricultural research site was designed as a paired watershed study in which monitoring stations were installed on the perennial streams draining both control and treatment watersheds. Linear mixed effects model analyses were conducted to determine if any statistically significant changes occurred in the water quality parameters before and after the AGSS was installed. Results indicated no significant changes (p = 0.51) in average event precipitation and runoff volumes before and after installation of the AGSS in either the treatment (NW) or control (SW) watersheds. However, the AGSS did significantly reduce the average suspended sediment concentration in the event runoff water (p = 0.02) in the NW from 972 to 263 mg L–1. In addition, particle size analyses, using light diffraction techniques, were conducted on soil samples taken from within the AGSS and adjacent valley and ridge top to determine if suspended sediments were being retained within the structure. Statistical analysis revealed a significantly (p clay inside the AGSS (37%) than outside (30%). These results indicate that the AGSS was successful in reducing the amount of suspended sediment transported to nearby

  9. Measurements of Two-Phase Suspended Sediment Transport in Breaking Waves Using Volumetric Three-Component Velocimetry

    Science.gov (United States)

    Ting, F. C. K.; LeClaire, P.

    2016-02-01

    Understanding the mechanisms of sediment pickup and distribution in breaking waves is important for modeling sediment transport in the surf zone. Previous studies were mostly concerned with bulk sediment transport under specific wave conditions. The distribution of suspended sediments in breaking waves had not been measured together with coherent flow structures. In this study, two-phase flow measurements were obtained under a train of plunging regular waves on a plane slope using the volumetric three-component velocimetry (V3V) technique. The measurements captured the motions of sediment particles simultaneously with the three-component, three-dimensional (3C3D) velocity fields of turbulent coherent structures (large eddies) induced by breaking waves. Sediment particles (solid glass spheres diameter 0.125 to 0.15 mm, specific gravity 2.5) were separated from fluid tracers (mean diameter 13 µm, specific gravity 1.3) based on a combination of particle spot size and brightness in the two-phase images. The interactions between the large eddies and glass spheres were investigated for plunger vortices generated at incipient breaking and for splash-up vortices generated at the second plunge point. The measured data show that large eddies impinging on the bottom was the primary mechanism which lift sediment particles into suspension and momentarily increased near-bed suspended sediment concentration. Although eddy impingement events were sporadic in space and time, the distributions of suspended sediments in the large eddies were not uniform. High suspended sediment concentration and vertical sediment flux were found in the wall-jet region where the impinging flow was deflected outward and upward. Sediment particles were also trapped and carried around by counter-rotating vortices (Figure 1). Suspended sediment concentration was significantly lower in the impingement region where the fluid velocity was downward, even though turbulent kinetic energy in the down flow was

  10. Compatibility study of trans-1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin (TNAD) with some energetic components and inert materials

    International Nuclear Information System (INIS)

    Yan Qilong; Li Xiaojiang; Zhang Laying; Li Jizhen; Li Hongli; Liu Ziru

    2008-01-01

    The compatibility of trans-1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin (TNAD) with some energetic components and inert materials of solid propellants was studied by using the pressure DSC method where, cyclotetramethylenetetranitroamine (HMX), cyclotrimethylenetrinitramine (RDX), 1,4-dinitropiperazine (DNP), 1.25/1-NC/NG mixture, lead 3-nitro-1,2,4-triazol-5-onate (NTO-Pb), aluminum powder (Al, particle size = 13.6 μm) and N-nitrodihydroxyethylaminedinitrate (DINA) were used as energetic components and polyethylene glycol (PEG), polyoxytetramethylene-co-oxyethylene (PET), addition product of hexamethylene diisocyanate and water (N-100), 2-nitrodianiline (2-NDPA), 1,3-dimethyl-1,3-diphenyl urea (C 2 ), carbon black (C.B.), aluminum oxide (Al 2 O 3 ), cupric 2,4-dihydroxy-benzoate (β-Cu), cupric adipate (AD-Cu) and lead phthalate (φ-Pb) were used as inert materials. It was concluded that the binary systems of TNAD with NTO-Pb, RDX, PET and Al powder are compatible, and systems of TNAD with DINA and HMX are slightly sensitive, and with 2-NDPA, φ-Pb, β-Cu, AD-Cu and Al 2 O 3 are sensitive, and with PEG, N-100, C 2 and C.B. are incompatible. The impact and friction sensitivity data of the TNAD and TNAD in combination with the other energetic materials under present study was also obtained, and there was no consequential affiliation between sensitivity and compatibility

  11. Temperature signal in suspended sediment export from an Alpine catchment

    Science.gov (United States)

    Costa, Anna; Molnar, Peter; Stutenbecker, Laura; Bakker, Maarten; Silva, Tiago A.; Schlunegger, Fritz; Lane, Stuart N.; Loizeau, Jean-Luc; Girardclos, Stéphanie

    2018-01-01

    Suspended sediment export from large Alpine catchments ( > 1000 km2) over decadal timescales is sensitive to a number of factors, including long-term variations in climate, the activation-deactivation of different sediment sources (proglacial areas, hillslopes, etc.), transport through the fluvial system, and potential anthropogenic impacts on the sediment flux (e.g. through impoundments and flow regulation). Here, we report on a marked increase in suspended sediment concentrations observed near the outlet of the upper Rhône River Basin in the mid-1980s. This increase coincides with a statistically significant step-like increase in basin-wide mean air temperature. We explore the possible explanations of the suspended sediment rise in terms of changes in water discharge (transport capacity), and the activation of different potential sources of fine sediment (sediment supply) in the catchment by hydroclimatic forcing. Time series of precipitation and temperature-driven snowmelt, snow cover, and ice melt simulated with a spatially distributed degree-day model, together with erosive rainfall on snow-free surfaces, are tested to explore possible reasons for the rise in suspended sediment concentration. We show that the abrupt change in air temperature reduced snow cover and the contribution of snowmelt, and enhanced ice melt. The results of statistical tests show that the onset of increased ice melt was likely to play a dominant role in the suspended sediment concentration rise in the mid-1980s. Temperature-driven enhanced melting of glaciers, which cover about 10 % of the catchment surface, can increase suspended sediment yields through an increased contribution of sediment-rich glacial meltwater, increased sediment availability due to glacier recession, and increased runoff from sediment-rich proglacial areas. The reduced extent and duration of snow cover in the catchment are also potential contributors to the rise in suspended sediment concentration through

  12. Determination of Heritage SSME Pogo Suppressor Resistance and Inertance from Waterflow Pulse Testing

    Science.gov (United States)

    McDougal, Chris; Eberhart, Chad; Lee, Erik

    2016-01-01

    Waterflow tests of a heritage Space Shuttle Main Engine pogo suppressor were performed to experimentally quantify the resistance and inertance provided by the suppressor. Measurements of dynamic pressure and flow rate in response to pulsing flow were made throughout the test loop. A unique system identification methodology combined all sensor measurements with a one-dimensional perturbational flow model of the complete water flow loop to spatially translate physical measurements to the device under test. Multiple techniques were then employed to extract the effective resistance and inertance for the pogo suppressor. Parameters such as steady flow rate, perturbational flow rate magnitude, and pulse frequency were investigated to assess their influence on the behavior of the pogo suppressor dynamic response. These results support validation of the RS-25 pogo suppressor performance for use on the Space Launch System Core Stage.

  13. Models of bending strength for Gilsocarbon graphites irradiated in inert and oxidising environments

    International Nuclear Information System (INIS)

    Eason, Ernest D.; Hall, Graham N.; Marsden, Barry J.; Heys, Graham B.

    2013-01-01

    This paper presents the development and validation of an empirical model of fast neutron damage and radiolytic oxidation effects on bending strength for the moulded Gilsocarbon graphites used in Advanced Gas-cooled Reactors (AGRs). The inert environment model is based on evidence of essentially constant strength as fast neutron dose increases in inert environment. The model of combined irradiation and oxidation calibrates that constant along with an exponential function representing the degree of radiolytic oxidation as measured by weight loss. The change in strength with exposure was found to vary from one AGR station to another. The model was calibrated to data on material trepanned from AGR moderator bricks after varying operating times

  14. Radiative neutrino mass and Majorana dark matter within an inert Higgs doublet model

    Science.gov (United States)

    Ahriche, Amine; Jueid, Adil; Nasri, Salah

    2018-05-01

    We consider an extension of the standard model (SM) with an inert Higgs doublet and three Majorana singlet fermions to address both origin and the smallness of neutrino masses and dark matter (DM) problems. In this setup, the lightest Majorana singlet fermion plays the role of DM candidate and the model parameter space can be accommodated to avoid different experimental constraints such as lepton flavor violating processes and electroweak precision tests. The neutrino mass is generated at one-loop level a la Scotogenic model and its smallness is ensured by the degeneracy between the C P -odd and C P -even scalar members of the inert doublet. Interesting signatures at both leptonic and hadronic colliders are discussed.

  15. Modeling the effects of size on patch dynamics of an inert tracer

    Directory of Open Access Journals (Sweden)

    P. Xiu

    2010-03-01

    Full Text Available Mesoscale iron enrichment experiments have revealed that additional iron affects the phytoplankton productivity and carbon cycle. However, the role of initial size of fertilized patch in determining the patch evolution is poorly quantified due to the limited observational capability and complex of physical processes. Using a three-dimensional ocean circulation model, we simulated different sizes of inert tracer patches that were only regulated by physical circulation and diffusion. Model results showed that during the first few days since release of inert tracer, the calculated dilution rate was found to be a linear function with time, which was sensitive to the initial patch size with steeper slope for smaller size patch. After the initial phase of rapid decay, the relationship between dilution rate and time became an exponential function, which was also size dependent. Therefore, larger initial size patches can usually last longer and ultimately affect biogeochemical processes much stronger than smaller patches.

  16. Spectroscopic Diagnostics of Barrier Discharge Plasmas in Mixtures of Zinc Diiodide with Inert Gases

    International Nuclear Information System (INIS)

    Guivan, N.N.; Malinin, A.N.

    2005-01-01

    The spectral characteristics of the emission of gas discharge atmospheric pressure plasmas in mixtures of zinc diiodide vapor with inert gases (He, Ne, Ar, Kr, and Xe) are investigated. The formation of a gas discharge plasma and the excitation of the components of a working mixture were performed in a high-frequency (with a repetition frequency of sinusoidal voltage pulses of 100 kHz) barrier discharge. The gas discharge emission was analyzed in the spectral range 200-900 nm with a resolution of 0.05 nm. Emission bands of ZnI(B-X) exciplex molecules and I* 2 excimer molecules, lines of inert gases, and emission bands of XeI* exciplex molecules (in Xe-containing mixtures) were revealed. It is ascertained that the strongest emission of ZnI* molecules is observed in ZnI 2 /He(Ne) mixtures. The regularities in the spectral characteristics of the gas discharge plasma emission are considered

  17. Distribution of inert gases in fines from the Cayley-Descartes region

    Science.gov (United States)

    Walton, J. R.; Lakatos, S.; Heymann, D.

    1973-01-01

    The inert gases in 14 different fines and in one sample of 2 to 4 mm fines from Apollo 16 were measured by mass spectroscopy with respect to trapped solar wind gases, cosmogenic gases, and 'parentless' Ar-40. Such studies are helpful for the understanding of regolith evolution, of transport of regolith fines, and of the lunar atmosphere. The Apollo 16 soils are unique because they represent, after Luna 20, the second and much more extensive record from the lunar highlands. The landing site presents the problem of materials from the Cayley Formation vs those from the Descartes Formation. There are two large, relatively fresh craters in the area, North Ray and South Ray, whose ejecta patterns may be recognized in the inert-gas record.

  18. Report on the treatability study for inerting small quantities of radioactive explosives and explosive components

    International Nuclear Information System (INIS)

    Loyola, V.M.; Reber, S.D.

    1996-02-01

    As a result of Sandia's radiation hardening testing on a variety of its explosive components, radioactive waste streams were generated and have to be disposed of as radioactive waste. Due to the combined hazards of explosives and radioactivity, Sandia's Radioactive and Mixed Waste Management organization did not have a mechanism for disposal of these waste streams. This report documents the study done to provide a method for the removal of the explosive hazard from those waste streams. The report includes the design of the equipment used, procedures followed, results from waste stream analog tests and the results from the actual explosive inerting tests on radioactive samples. As a result of the inerting treatment, the waste streams were rendered non-explosive and, thus, manageable through normal radioactive waste disposal channels

  19. Assessment of a chemical getter for scavenging tritium from an inert gas

    International Nuclear Information System (INIS)

    Maienschein, J.L.

    1976-01-01

    Results are presented of a study aimed at determining the feasibility of using chemical getter beds to scavenge tritium from inert gases. Two types of getter bed, fixed and fluidized, were considered, using cerium as the getter material. Mathematical-modeling results and capital-cost estimates indicate that not only is the gettering approach technically feasible, it could lead to considerable cost savings over catalytic oxidation, the tritium-removal method traditionally used

  20. The smoke ion source: A device for the generation of cluster ions via inert gas condensation

    International Nuclear Information System (INIS)

    McHugh, K.M.; Sarkas, H.W.; Eaton, J.G.; Bowen, K.H.; Westgate, C.R.

    1989-01-01

    We report the development of an ion source for generating intense, continuous beams of both positive and negative cluster ions. This device is the result of the marriage of the inert gas condensation method with techniques for injecting electrons directly into expanding jets. In the preliminary studies described here, we have observed cluster ion size distributions ranging from n=1-400 for Pb n + and Pb n - and from n=12-5700 for Li n - . (orig.)

  1. Testes de toxicidade aguda através de bioensaios no extrato solubilizado dos resíduos classe II A - não inertes e classe II B - inertes Acute toxicity tests by bioassays applied to the solubilized extracts of solid wastes class II A - non inerts and class II B - inerts

    Directory of Open Access Journals (Sweden)

    Nébora Liz Vendramin Brasil Rodrigues

    2007-03-01

    Full Text Available A grande diversidade de substâncias potencialmente tóxicas contribuem para a deterioração do meio ambiente. O objetivo deste trabalho foi propor a utilização de bioensaios, através de testes de toxicidade aguda com Daphnia magna e Vibrio fischeri, como mais um parâmetro a ser analisado no extrato solubilizado dos resíduos que, segundo a NBR 10004/04 fossem classificados como classe II A - não inertes ou classe II B - inertes. Realizaram-se, também, testes de toxicidade no drenado dos aterros classe II A e II B. Verificou-se que a toxicidade foi constatada nos extratos solubilizados dos 18 resíduos analisados e que, apenas três das amostras estariam próprias para lançamento, ou seja os resíduos 04, 14 e 15. Já, a toxicidade encontrada no drenado dos aterros, ficou muito superior do que a toxicidade de cada extrato solubilizado analisado separadamente.A great diversity of substances potencially toxic contributes to the deterioration of the environment. The aim of this research was to propose the use of bioassays using Daphnia magna and Vibrio fischeri, as another parameter to be analyzed in the solubilized extraction of waste according to NBR 10004/04 and classified as class II A - non inerts or class II B - inerts. Besides, another test was performed to measure the level of toxicity in the drainage of the landfill class II A and II B. It was verified that the toxicity found in the solubilized extracts of the 18 wastes analysed.Only 3 wastes (04, 14 and 15 were within the emission limits. On the other hand the toxicity found in the drainage of the landfill, from which all the samples came from, was much higher than the individual one.

  2. The inert doublet model: a new archetype of WIMP dark matter?

    International Nuclear Information System (INIS)

    Tytgat, M Hg

    2008-01-01

    The Inert Doublet Model (IDM) is a two doublet extension of the Higgs-Brout-Englert sector of the Standard Model with a Z2 symmetry in order to prevent FCNC. If the Z2 symmetry is not spontaneously broken, the lightest neutral extra scalar is a dark matter candidate. We briefly review the phenomenology of the model, emphasizing its relevance for the issue of Electroweak Symmetry Breaking (EWSB) and the prospects for detection of dark matter

  3. Fuel hydrogen retention of tungsten and the reduction by inert gas glow discharges

    Energy Technology Data Exchange (ETDEWEB)

    Hino, T., E-mail: tomhino@qe.eng.hokudai.ac.jp [Laboratory of Plasma Physics and Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Yamauchi, Y.; Kimura, Y. [Laboratory of Plasma Physics and Engineering, Hokkaido University, Sapporo 060-8628 (Japan); Nishimura, K. [National Institute for Fusion Science, Toki-shi, Gifu-ken 509-5292 (Japan); Ueda, Y. [Graduate School of Engineering, Osaka University, Suita-shi 565-0872 (Japan)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer The performances of inert gas glow discharges for reduction of fuel hydrogen retention in tungsten were systematically investigated. Black-Right-Pointing-Pointer For the tungsten with rough surface structure, the reduction of fuel hydrogen retention by inert gas discharges is quite small. Black-Right-Pointing-Pointer The deuterium glow discharge is quite useful to reduce the tritium retention in plasma facing walls in fusion reactor. Black-Right-Pointing-Pointer The wall baking with temperature higher than 700-800 K is also useful to reduce the tritium retention in plasma facing walls. - Abstract: Polycrystalline tungsten was exposed to deuterium glow discharge followed by He, Ne or Ar glow discharge. The amount of retained deuterium in the tungsten was measured using residual gas analysis. The amount of desorbed deuterium during the inert gas glow discharge was also measured. The amount of retained deuterium was 2-3 times larger compared with a case of stainless steel. The ratios of desorbed amount of deuterium by He, Ne and Ar glow discharges were 4.6, 3.1 and 2.9%, respectively. These values were one order of magnitude smaller compared with the case of stainless steel. The inert gas glow discharge is not suitable to reduce the fuel hydrogen retention for tungsten walls. However, the wall baking with a temperature higher than 700 K is suitable to reduce the fuel hydrogen retention. It is also shown that the use of deuterium glow discharge is effective to reduce the in-vessel tritium inventory in fusion reactors through the hydrogen isotope exchange.

  4. Substances inertes et plantes à effet insecticide utilisées dans la ...

    African Journals Online (AJOL)

    Les insecticides naturels tels que les plantes à effet insecticide et les substances inertes (sable, cendre, terres à diatomées,…) méritent d'être valorisées afin de réduire l'utilisation des insecticides chimiques et protéger l'environnement. Ce travail basé sur une revue documentaire fouillée et actualisée vise à faire la genèse ...

  5. Bomb radiocarbon in metabolically inert tissues from terrestrial and marine mammals

    International Nuclear Information System (INIS)

    Bada, J.L.; Vrolijk, C.D.; Brown, S.; Druffel, E.R.M.; Hedges, R.E.M.

    1987-01-01

    We report here radiocarbon measurements of monkey eye lens nucleus proteins and a narwhal tusk, biological tissues which have sampled the bomb radiocarbon signal in different ways. The results confirm the metabolic inertness of eye lens nucleus proteins and demonstrate the feasibility of measuring radiocarbon in small samples of biological tissue using accelerator mass spectrometry (AMS). The narwhal tusk provides a unique record of the radiocarbon activity in Arctic Ocean waters over most of the 20th century

  6. Dissolved helium, inert gases, radium and radon in groundwaters from the Altnabreac research site

    International Nuclear Information System (INIS)

    Andrews, J.N.; Kay, R.L.F.

    1985-01-01

    A groundwater geochemical study has been carried out at Altnabreac, Cenithness, Scotland, to investigate the feasibility of disposal of high-level radioactive wastes in crystalline rock. A groundwater flow model was constructed for sampling a section at depths up to 300 m. Measurements of inert gases dissolved in groundwaters are used, with parallel measurements of 14 C, tritium, oxygen and hydrogen isotopes to infer groundwater ages and residence times. (UK)

  7. Technical basis for storage of Zircaloy-clad spent fuel in inert gases

    International Nuclear Information System (INIS)

    Johnson, A.B. Jr.; Gilbert, E.R.

    1983-09-01

    The technical bases to establish safe conditions for dry storage of Zircaloy-clad fuel are summarized. Dry storage of fuel with zirconium alloy cladding has been licensed in Canada, the Federal Republic of Germany, and Switzerland. Dry storage demonstrations, hot cell tests, and modeling have been conducted using Zircaloy-clad fuel. The demonstrations have included irradiated boiling water reactor, pressurized heavy-water reactor, and pressurized water reactor fuel assemblies. Irradiated fuel has been emplaced in and retrieved from metal casks, dry wells, silos, and a vault. Dry storage tests and demonstrations have involved about 15,000 fuel rods, and about 5600 rods have been monitored during dry storage in inert gases with maximum cladding temperatures ranging from 50 to 570 0 C. Although some tests and demonstrations are still in progress, there is currently no evidence that any rods exposed to inert gases have failed (one PWR rod exposed to an air cover gas failed at about 270 0 C). Based on this favorable experience, it is concluded that there is sufficient information on fuel rod behavior, storage conditions, and potential cladding failure mechanisms to support licensing of dry storage in the US. This licensing position includes a requirement for inert cover gases and a maximum cladding temperature guideline of 380 0 C for Zircaloy-clad fuel. Using an inert cover gas assures that even if fuel with cladding defects were placed in dry storage, or if defects develop during storage, the defects would not propagate. Tests and demonstrations involving Zircaloy-clad rods and assemblies with maximum cladding temperatures above 400 0 C are in progress. When the results from these tests have been evaluated, the viability of higher temperature limits should be examined. Acceptable conditions for storage in air and dry storage of consolidated fuel are issues yet to be resolved

  8. Dark Matter candidate in Inert Doublet Model with additional local gauge symmetry U (1)

    International Nuclear Information System (INIS)

    Gaitán, R.; De Oca, J.H. Montes; Garcés, E. A.; Cabral-Rosetti, L. G.

    2016-01-01

    We consider the Inert Doublet Model (IDM) with an additional local gauge symmetry U (1) and a complex singlet scalar to break the symmetry U (1). The continuous symmetry U (1) is introduced to control the CP-conserving interaction instead of some discrete symmetries as usually. We present the mass spectrum for neutral scalar and gauge bosons and the values of the charges under U (1) for which the model could have a candidate to dark matter. (paper)

  9. Mixed PWR core loadings with inert matrix Pu-fuel assemblies

    International Nuclear Information System (INIS)

    Stanculescu, A.; Kasemeyer, U.; Paratte, J.-M.; Chawla, R.

    1999-01-01

    The most efficient way to enhance plutonium consumption in light water reactors is to eliminate the production of plutonium all together. This requirement leads to fuel concepts in which the uranium is replaced by an inert matrix. At PSI, studies have focused on employing ZrO 2 as inert matrix. Adding a burnable poison to such a fuel proves to be necessary. As a result of scoping studies, Er 2 O 3 was identified as the most suitable burnable poison material. The results of whole-core three-dimensional neutronics analyses indicated, for a present-day 1000 MW e pressurised water reactor, the feasibility of an asymptotic equilibrium four-batch cycle fuelled solely with the proposed PuO 2 -Er 2 O 3 -ZrO 2 inert matrix fuel (IMF). The present paper presents the results of more recent investigations related to 'real-life' situations, which call for transition configurations in which mixed IMF and UO 2 assembly loadings must be considered. To determine the influence of the introduction of IMF assemblies on the characteristics of a UO 2 -fuelled core, three-dimensional full-core calculations have been performed for a present-day 1000 MW e PWR containing up to 12 optimised IMF assemblies. (author)

  10. Effects of radiative heat transfer on the turbulence structure in inert and reacting mixing layers

    International Nuclear Information System (INIS)

    Ghosh, Somnath; Friedrich, Rainer

    2015-01-01

    We use large-eddy simulation to study the interaction between turbulence and radiative heat transfer in low-speed inert and reacting plane temporal mixing layers. An explicit filtering scheme based on approximate deconvolution is applied to treat the closure problem arising from quadratic nonlinearities of the filtered transport equations. In the reacting case, the working fluid is a mixture of ideal gases where the low-speed stream consists of hydrogen and nitrogen and the high-speed stream consists of oxygen and nitrogen. Both streams are premixed in a way that the free-stream densities are the same and the stoichiometric mixture fraction is 0.3. The filtered heat release term is modelled using equilibrium chemistry. In the inert case, the low-speed stream consists of nitrogen at a temperature of 1000 K and the highspeed stream is pure water vapour of 2000 K, when radiation is turned off. Simulations assuming the gas mixtures as gray gases with artificially increased Planck mean absorption coefficients are performed in which the large-eddy simulation code and the radiation code PRISSMA are fully coupled. In both cases, radiative heat transfer is found to clearly affect fluctuations of thermodynamic variables, Reynolds stresses, and Reynolds stress budget terms like pressure-strain correlations. Source terms in the transport equation for the variance of temperature are used to explain the decrease of this variance in the reacting case and its increase in the inert case

  11. Viability of inert matrix fuel in reducing plutonium amounts in reactors

    International Nuclear Information System (INIS)

    2006-08-01

    Reactors worldwide have produced more than 2000 tonnes of plutonium, contained in spent fuel or as separated forms through reprocessing. Disposition of fissile materials has become a primary concern of nuclear non-proliferation efforts. There is a significant interest in IAEA Member States to develop proliferation resistant nuclear fuel cycles for incineration of plutonium such as inert matrix fuels (IMFs). The present report summarises R and D work on inert matrix fuel for plutonium and (to a lesser extent) minor actinide stock-pile reduction, and discusses the possible strategies to include inert matrix fuel approaches to the nuclear fuel cycle. The publication reviews the status of potential IMF candidates and describes several identified candidate materials for both fast and thermal reactors: MgO, ZrO2, SiC, Zr alloy, SiAl, ZrN; some of these have undergone test irradiations and post-irradiation examination. Also discussed are modelling of IMF fuel performance and safety analysis. System studies have identified strategies for both implementation of IMF fuel as homogeneous or heterogeneous phases, as assemblies or core loadings and in existing reactors in the shorter term, as well as in new reactors in the longer term

  12. AGENTES INERTES PARA CONTOLE DE TOMBAMENTO EM SEMENTEIRAS DE OLERÍCOLAS

    Directory of Open Access Journals (Sweden)

    Ricardo Silveiro Balardin

    1994-01-01

    Full Text Available RESUMO Este trabalho foi conduzido com o objetivo de avaliar o comportamento de materiais inertes para controle de tombamento durante a emergência. Os tratamentos foram cobertura do sulco de semeadura com areia e serragem, tratamento químico com brometo de metila e uma testemunha. Os parâmetros avaliados foram percentagem e velocidade de emergência, percentagem de tombamento de pré e pós-emergência. Os dados obtidos permitiram concluir que, dentre os materiais inertes testados, a areia pode constituir-se em uma alternativa eficiente no controle do tombamento em sementeiras de repolho e beterraba, pois permitiu o maior número de plântulas emergidas e o menor número de plântulas tombadas não alterando a velocidade de emergência, enquanto que nas sementeiras de alface a utilização dos materiais inertes prejudicou a emergência normal das plântulas, não se constituindo em agente de controle eficiente.

  13. Fabrication of Miniature Titanium Capsule for Brachytherapy Sources Using Tungsten Inert Gas Method

    International Nuclear Information System (INIS)

    Naghdi, R.; Sheibani, Sh.; Tamizifar, M.

    2013-01-01

    The capsules containing radioactive materials as brachytherapy sources are used for implanting into some target organs for malignant disorders treatments, such as prostate, eyes, and brain cancers. The conventional method for sealing the tubes is to weld them using a laser beam which is now a part of tube melting methods (self welding). The purpose of this study was to seal miniature titanium tubes containing radioactive materials in the form of capsules. This study introduced a new method based on melting process. A piece of commercially pure titanium grade 2 in the form of disk was used for the experiment. The sample was melted at the top of the tube by a Tungsten Inert Gas welding device for a short time duration. After completion of the melting, the disk in the form of a drop was mixed with a small part of it and both were solidified and hence closed the tube. We evaluated the tubes for the metallurgical properties and seal process which took place by Tungsten Inert Gas in different zones, including the heat affected zone, fusion zone, and interface of the joint of the drop to the tube. Finally, the produced samples were tested according to the ISO2919 and ISO9978 and the results confirmed the Disk and Tungsten Inert Gas procedure.

  14. Method of making composition suitable for use as inert electrode having good electrical conductivity and mechanical properties

    Science.gov (United States)

    Ray, S.P.; Rapp, R.A.

    1986-04-22

    An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metals or metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily. 8 figs.

  15. Cancer-treating composition containing inductively-heatable particles

    International Nuclear Information System (INIS)

    Gordon, R.T.

    1978-01-01

    A cancer-treating composition including minute particles suspended in an aqueous solution in dosage form is described. This makes it possible to introduce into the interior of the cells of living tissue minute particles, with magnetic properties, which are inductively heated when subjected to a high frequency alternating electromagnetic field. Incorporating specific radioisotopes or tumor-specific antibodies bound to the particles increases selectivity and affinity of cancer cells for the particles. The particles may be used to deliver a chemotherapeutic agent primarily to the interior of the cancer cells by encapsulating the chemotherapeutic agent within the particles for release when the high frequency alternating electromagnetic field is applied. (author)

  16. Suspended microstructures of epoxy based photoresists fabricated with UV photolithography

    DEFF Research Database (Denmark)

    Hemanth, Suhith; Anhøj, Thomas Aarøe; Caviglia, Claudia

    2017-01-01

    In this work we present an easy, fast, reliable and low cost microfabrication technique for fabricating suspended microstructures of epoxy based photoresistswith UV photolithography. Two different fabrication processes with epoxy based resins (SU-8 and mr-DWL) using UV exposures at wavelengths...... of 313 nm and 405 nm were optimized and compared in terms of structural stability, control of suspended layer thickness and resolution limits. A novel fabrication process combining the two photoresists SU-8 and mr-DWL with two UV exposures at 365 nm and 405 nm respectively provided a wider processing...... window for definition of well-defined suspended microstructures with lateral dimensions down to 5 μmwhen compared to 313 nm or 365 nm UV photolithography processes....

  17. Flywheel Energy Storage System Suspended by Hybrid Magnetic Bearing

    Science.gov (United States)

    Owusu-Ansah, Prince; Hu, Yefa; Misbawu, Adam

    This work presents a prototype flywheel energy storage system (FESS) suspended by hybrid magnetic bearing (HMB) rotating at a speed of 20000rpm with a maximum storage power capacity of 30W with a maximum tip speed of 300m/s. The design presented is an improvement of most existing FESS, as the design incorporates a unique feature in that the upper and the lower rotor and stator core are tapered which enhances larger thrust and much lower radial force to be exerted on the system. Without any adverse effect being experienced by the model. The work also focuses on the description of developing a prototype FESS suspended by HMB using solid works as a basis of developing in the nearer future a more improved FESS suspended by HMB capable of injecting the ever increasing high energy demand situation in the 21st century and beyond.

  18. Chemical concentrations in water and suspended sediment, Green River to Lower Duwamish Waterway near Seattle, Washington, 2016–17

    Science.gov (United States)

    Conn, Kathleen E.; Black, Robert W.; Peterson, Norman T.; Senter, Craig A.; Chapman, Elena A.

    2018-01-05

    From August 2016 to March 2017, the U.S. Geological Survey (USGS) collected representative samples of filtered and unfiltered water and suspended sediment (including the colloidal fraction) at USGS streamgage 12113390 (Duwamish River at Golf Course, at Tukwila, Washington) during 13 periods of differing flow conditions. Samples were analyzed by Washington-State-accredited laboratories for a large suite of compounds, including metals, dioxins/furans, semivolatile compounds including polycyclic aromatic hydrocarbons, butyltins, the 209 polychlorinated biphenyl (PCB) congeners, and total and dissolved organic carbon. Concurrent with the chemistry sampling, water-quality field parameters were measured, and representative water samples were collected and analyzed for river suspended-sediment concentration and particle-size distribution. The results provide new data that can be used to estimate sediment and chemical loads transported by the Green River to the Lower Duwamish Waterway.

  19. Polarization-based enhancement of ocean color signal for estimating suspended particulate matter: radiative transfer simulations and laboratory measurements.

    Science.gov (United States)

    Liu, Jia; He, Xianqiang; Liu, Jiahang; Bai, Yan; Wang, Difeng; Chen, Tieqiao; Wang, Yihao; Zhu, Feng

    2017-04-17

    Absorption and scattering by molecules, aerosols and hydrosols, and the reflection and transmission over the sea surface can modify the original polarization state of sunlight. However, water-leaving radiance polarization, containing embedded water constituent information, has largely been neglected. Here, the efficiency of the parallel polarization radiance (PPR) for enhancing ocean color signal of suspended particulate matter is examined via vector radiative transfer simulations and laboratory experiments. The simulation results demonstrate that the PPR has a slightly higher ocean color signal at the top-of-atmosphere as compared with that of the total radiance. Moreover, both the simulations and laboratory measurements reveal that, compared with total radiance, PPR can effectively enhance the normalized ocean color signal for a large range of observation geometries, wavelengths, and suspended particle concentrations. Thus, PPR has great potential for improving the ocean color signal detection from satellite.

  20. Characterization and radionuclides sorption of suspended particulate matters in freshwater according to their settling kinetics

    International Nuclear Information System (INIS)

    Brach-Papa, C.; Boyer, P.; Amielh, M.; Anselmet, F.

    2004-01-01

    In freshwater, the transfers of radionuclides depend both on exchanges between liquid and solid phases and on mass transfers between suspended matter and bottom sediment. Whereas the former ones depend on chemical processes (such as sorption/desorption, complexation, the latter ones are regulated by hydrological and sedimentary considerations (dispersion, erosion, deposit closely related to the interactions between flow, suspended matter and bed sediment. Some of our previous studies highlight the need to consider the matter heterogeneity and its specific sediment dynamics to correctly report the inhomogeneity of fluxes in time and in space. These considerations lead us to develop experimental methods to distinguish the different matter classes, present in natural water, mainly according to their erosion threshold and settling kinetics. In this context, this paper presents the experimental protocol TALISMEN to characterize a natural bulk suspension according the identification of its main settling kinetics groups. In a first step, this identification is achieved by the use of a settling tank, that allows the monitoring of the suspended solid concentration at various depths, combined to a vertical mono-dimensional settling model applying a multi-class approach. In a second step, the particle groups are isolated and their physico-chemical properties are determined ( i.e mineral composition, specific surface area, particulate organic carbon, in order to fully characterized them. In a last one, the sorption property of each group toward radionuclides is determined by the measurements of its distribution coefficients (Kd). The results confirm the interest to consider these heterogeneities for the modelling of the radionuclides transfer in freshwater. From one group to other, these heterogeneities appear at two levels: 1) their sediment dynamics and 2) their radionuclides sorption properties. These conclusions can be equally applying to others xenobiotics as heavy metals

  1. Experimental study on kinetics oil oil-suspended particulate matter aggregation

    International Nuclear Information System (INIS)

    Sun, J.; Environment Canada, Ottawa, ON; Khelifa, A.; Wang, Z.; Brown, C.; Fieldhouse, B.; Yang, C.; Zheng, X.; Wong, S.; So, L.C.

    2009-01-01

    Past studies of oil spills have shown that oil suspended particulate matter aggregates (OSAs) play a role in enhancing the natural cleansing of oiled shorelines. OSAs result from aggregation between suspended oil droplets and suspended particulate matter (SPM) in aquatic environments. During this process, oil dispersion into the water column is significantly increased since the surface of the oil droplet is surrounded by sediment particles. In addition, the accelerated biodegradation of the oil can be attributed to the greater oil-water contact area. This study focused on the kinetic aspects of OSA formation, with particular reference to the time scale of this process and its significance to oil dispersion following oil spills in water. A laboratory study was conducted to measure the time scale of OSA formation and its variations with mixing conditions. A reciprocating shaker and various oil/sediment mixtures were used to prepare the OSAs. Standard reference material 1941b was used as the natural sediment mixed with Arabian medium crude and artificial seawater under various mixing energies. The sediment-to-oil ratio remained constant for all experiments. Gas chromatography-flame ionization detection (GC-FID) analysis was used to measure the total petroleum hydrocarbons (TPH) trapped in negatively buoyant OSAs. Results showed that the TPH in OSAs increased exponentially with shaking time and reached an equilibrium value within 3 hours. The equilibrium decreased from 3 hours to 1.3 hours when the shaking rate increased from 2.0 to 2.3 Hz. It was concluded that high mixing energy enhances OSA formation and shortens the time for OSA formation. 42 refs., 6 tabs., 5 figs

  2. Experimental study on kinetics oil oil-suspended particulate matter aggregation

    Energy Technology Data Exchange (ETDEWEB)

    Sun, J. [Ocean Univ. of China, Qingdoa (China). Environmental Science and Engineering Inst.; Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Section, Emergencies, Operational Analytical Laboratories and Research Support Division; Khelifa, A.; Wang, Z.; Brown, C.; Fieldhouse, B.; Yang, C. [Environment Canada, Ottawa, ON (Canada). Emergencies Science and Technology Section, Emergencies, Operational Analytical Laboratories and Research Support Division; Zheng, X. [Ocean Univ. of China, Qingdoa (China). Environmental Science and Engineering Inst.; Wong, S. [Ottawa Univ., ON (Canada). Dept. of Chemistry; So, L.C. [Waterloo Univ., ON (Canada). Faculty of Engineering

    2009-07-01

    Past studies of oil spills have shown that oil suspended particulate matter aggregates (OSAs) play a role in enhancing the natural cleansing of oiled shorelines. OSAs result from aggregation between suspended oil droplets and suspended particulate matter (SPM) in aquatic environments. During this process, oil dispersion into the water column is significantly increased since the surface of the oil droplet is surrounded by sediment particles. In addition, the accelerated biodegradation of the oil can be attributed to the greater oil-water contact area. This study focused on the kinetic aspects of OSA formation, with particular reference to the time scale of this process and its significance to oil dispersion following oil spills in water. A laboratory study was conducted to measure the time scale of OSA formation and its variations with mixing conditions. A reciprocating shaker and various oil/sediment mixtures were used to prepare the OSAs. Standard reference material 1941b was used as the natural sediment mixed with Arabian medium crude and artificial seawater under various mixing energies. The sediment-to-oil ratio remained constant for all experiments. Gas chromatography-flame ionization detection (GC-FID) analysis was used to measure the total petroleum hydrocarbons (TPH) trapped in negatively buoyant OSAs. Results showed that the TPH in OSAs increased exponentially with shaking time and reached an equilibrium value within 3 hours. The equilibrium decreased from 3 hours to 1.3 hours when the shaking rate increased from 2.0 to 2.3 Hz. It was concluded that high mixing energy enhances OSA formation and shortens the time for OSA formation. 42 refs., 6 tabs., 5 figs.

  3. Theoretical and experimental drying of a cylindrical sample by applying hot air and infrared radiation in an inert medium fluidized bed

    Directory of Open Access Journals (Sweden)

    B. Honarvar

    2012-06-01

    Full Text Available Drying of a cylindrical sample in a fluidized bed dryer containing inert particles was studied. For this purpose, a pilot-scaled fluidized bed dryer was constructed in which two different heat sources, hot air and infrared radiation were applied, and pieces of carrot were chosen as test samples. The heat transfer coefficient for cylindrical objects in a fluidized bed was also measured. The heat absorption coefficient for carrot was studied. The absorption coefficient can be computed by dividing the absorbed heat by the carrot to the heat absorbed for the water and black ink. In this regard, absorbed heat values by the carrot, water and black ink were used A mathematical model was proposed based on the mass and heat transfer phenomena within the drying sample. The results obtained by the proposed model were in favorable agreement with the experimental data.

  4. Suspended particulate matter in railway coaches

    Science.gov (United States)

    Leutwyler, M.; Siegmann, K.; Monn, Ch

    Measurements of particles intercity connection in Switzerland. All trains are electrified and the indoor air quality is regulated by a mechanical ventilation system. In the smoker sections, pPAH levels were on average about 250 ng m -3, PM 10 levels about 950 μg m -3. In the non-smoker section, pPAH levels were about 45 ng m -3 and PM 10 levels about 210 μg m -3. Our observations suggest that smoking is the most important source of pPAH and PM 10. The spatial variation within the coaches indicates that pPAHs spread out from the smoker compartments into the non-smoker compartments. For PM 10, resuspended material may also be a source of airborne PM 10 but the contribution within this non-stop connection with most of the passengers being seated all the time was probably small. The influence of outdoor PM 10 and pPAH on indoor levels was negligible. Both pollutants, pPAH and PM 10 were largely elevated in the smoker as well as in the non-smoker compartments. Despite this fact, a questionnaire on the quality of travelling showed that most of the passengers felt well and only a small proportion felt uneasy.

  5. Colorimetry Technique for Scalable Characterization of Suspended Graphene.

    Science.gov (United States)

    Cartamil-Bueno, Santiago J; Steeneken, Peter G; Centeno, Alba; Zurutuza, Amaia; van der Zant, Herre S J; Houri, Samer

    2016-11-09

    Previous statistical studies on the mechanical properties of chemical-vapor-deposited (CVD) suspended graphene membranes have been performed by means of measuring individual devices or with techniques that affect the material. Here, we present a colorimetry technique as a parallel, noninvasive, and affordable way of characterizing suspended graphene devices. We exploit Newton's rings interference patterns to study the deformation of a double-layer graphene drum 13.2 μm in diameter when a pressure step is applied. By studying the time evolution of the deformation, we find that filling the drum cavity with air is 2-5 times slower than when it is purged.

  6. Optical fiber end-facet polymer suspended-mirror devices

    Science.gov (United States)

    Yao, Mian; Wu, Jushuai; Zhang, A. Ping; Tam, Hwa-Yaw; Wai, P. K. A.

    2017-04-01

    This paper presents a novel optical fiber device based on a polymer suspended mirror on the end facet of an optical fiber. With an own-developed optical 3D micro-printing technology, SU-8 suspended-mirror devices (SMDs) were successfully fabricated on the top of a standard single-mode optical fiber. Optical reflection spectra of the fabricated SU- 8 SMDs were measured and compared with theoretical analysis. The proposed technology paves a way towards 3D microengineering of the small end-facet of optical fibers to develop novel fiber-optic sensors.

  7. Suspended Matter, Chl-a, CDOM, Grain Sizes, and Optical Properties in the Arctic Fjord-Type Estuary, Kangerlussuaq, West Greenland During Summer

    DEFF Research Database (Denmark)

    Lund-Hansen, L. C.; Andersen, T. J.; Nielsen, Morten Holtegaard

    2010-01-01

    Optical constituents as suspended particulate matter (SPM), chlorophyll (Chl-a), colored dissolved organic matter (CDOM), and grain sizes were obtained on a transect in the arctic fjord-type estuary Kangerlussuaq (66A degrees) in August 2007 along with optical properties. These comprised diffuse...... water outlet. Values of optical constituents and properties decreased with distance from the melt water outlet to a more or less constant level in central and outer part of the estuary. There was a strong correlation between inorganic suspended matter (SPMI) and diffuse attenuation coefficient K (d...... from the very high turbid melt water outlet to clear marine waters. Results showed a strong spatial variation with high values as for suspended matter concentrations, CDOM, diffuse attenuation coefficient K (d)(PAR), particle beam attenuation coefficients (c (p)), and reflectance R(-0, PAR) at the melt...

  8. TIG AISI-316 welds using an inert gas welding chamber and different filler metals: Changes in mechanical properties and microstructure

    Energy Technology Data Exchange (ETDEWEB)

    Pascual, M.; Salas, F.; Carcel, F.J.; Perales, M.; Sanchez, A.

    2010-07-01

    This report analyses the influence of the use of an inert gas welding chamber with a totally inert atmosphere on the microstructure and mechanical properties of austenitic AISI 316L stainless steel TIG welds, using AISI ER316L, AISI 308L and Inconel 625 as filler metals. When compared with the typical TIG process, the use of the inert gas chamber induced changes in the microstructure, mainly an increase in the presence of vermicular ferrite and ferrite stringers, what resulted in higher yield strengths and lower values of hardness. Its effect on other characteristics of the joins, such as tensile strength, depended on the filler metal. The best combination of mechanical characteristics was obtained when welding in the inert gas chamber using Inconel 625 as filler metal. (Author). 12 refs.

  9. Quantification of Suspended Sediment Load by Double Correlation in the Watershed of Chellif (Algeria

    Directory of Open Access Journals (Sweden)

    Bouchelkia Hamid

    2014-07-01

    Full Text Available The sediment transport in rivers in Algeria is very high. However, it is poorly quantified in some wadis because of the absence and the shortage of data especially the concentration of fine particles and also the unavailability of gauging stations. To fill this gap, a technique for estimating sediment yield, based on data recorded at the gauging station has been developed. The estimation of suspended sediment yield was conducted by a statistical analysis with double correlation on average daily flow and solid concentrations. The results obtained by applying this model to the watershed Chellif are very encouraging because the correlation coefficients of the found models are between 61% and 91% for the first correlation and between 86% and 97% for the second correlation. The estimated quantity of suspended sediment load is between 2.35 and 4.12 million tonnes per year, it appears important; This is due to the vulnerability of the Chellif basin facing erosion, the importance of its area and the importance of fluid flows in wadi Cheliff and its torrential regime. Mention here some of the results and their significance to the study.

  10. SAFL Baffle retrofit for suspended sediment removal in storm sewer sumps.

    Science.gov (United States)

    Howard, Adam; Mohseni, Omid; Gulliver, John; Stefan, Heinz

    2011-11-15

    Standard sumps (manholes) provide a location for pipe junctions and maintenance access in stormwater drainage systems. Standard sumps can also remove sand and silt particles from stormwater, but have a high propensity for washout of the collected sediment. With appropriate maintenance these sumps may qualify as a stormwater best management practice (BMP) device for the removal of suspended sediment from stormwater runoff. To decrease the maintenance frequency and prevent standard sumps from becoming a source of suspended sediment under high flow conditions, a porous baffle, named the SAFL Baffle, has been designed and tested as a retrofit to the sump. Multiple configurations with varying percent open area and different angles of attack were evaluated in scale models. An optimum configuration was then constructed at the prototype scale and evaluated for both removal efficiency and washout. Results obtained with the retrofit indicate that with the right baffle dimensions and porosity, sediment washout from the sump at high flow rates can be almost eliminated, and removal efficiency can be significantly increased at low flow rates. Removal efficiency and washout functions have been developed for standard sumps retrofitted with the SAFL Baffle. The results of this research provide a new, versatile stormwater treatment device and implemented new washout and removal efficiency testing procedures that will improve research and development of stormwater treatment devices. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. A suspended boron foil multi-wire proportional counter neutron detector

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Kyle A.; Edwards, Nathaniel S.; Hinson, Niklas J.; Wayant, Clayton D.; McGregor, Douglas S.

    2014-12-11

    Three natural boron foils, approximately 1.0 cm in diameter and 1.0 µm thick, were obtained from The Lebow Company and suspended in a multi-wire proportional counter. Suspending the B foils allowed the alpha particle and Li ion reaction products to escape simultaneously, one on each side of the foil, and be measured concurrently in the gas volume. The thermal neutron response pulse-height spectrum was obtained and two obvious peaks appear from the 94% and 6% branches of the {sup 10}B(n,α){sup 7}Li neutron reaction. Scanning electron microscope images were collected to obtain the exact B foil thicknesses and MCNP6 simulations were completed for those same B thicknesses. Pulse-height spectra obtained from the simulations were compared to experimental data and matched well. The theoretical intrinsic thermal–neutron detection efficiency for enriched {sup 10}B foils was calculated and is presented. Additionally, the intrinsic thermal neutron detection efficiency of the three natural B foils was calculated to be 3.2±0.2%.

  12. A suspended boron foil multi-wire proportional counter neutron detector

    Science.gov (United States)

    Nelson, Kyle A.; Edwards, Nathaniel S.; Hinson, Niklas J.; Wayant, Clayton D.; McGregor, Douglas S.

    2014-12-01

    Three natural boron foils, approximately 1.0 cm in diameter and 1.0 μm thick, were obtained from The Lebow Company and suspended in a multi-wire proportional counter. Suspending the B foils allowed the alpha particle and Li ion reaction products to escape simultaneously, one on each side of the foil, and be measured concurrently in the gas volume. The thermal neutron response pulse-height spectrum was obtained and two obvious peaks appear from the 94% and 6% branches of the 10B(n,α)7Li neutron reaction. Scanning electron microscope images were collected to obtain the exact B foil thicknesses and MCNP6 simulations were completed for those same B thicknesses. Pulse-height spectra obtained from the simulations were compared to experimental data and matched well. The theoretical intrinsic thermal-neutron detection efficiency for enriched 10B foils was calculated and is presented. Additionally, the intrinsic thermal neutron detection efficiency of the three natural B foils was calculated to be 3.2±0.2%.

  13. Characterisation of the suspended particulate matter in a stratified estuarine environment employing complementary techniques

    Science.gov (United States)

    Thomas, Luis P.; Marino, Beatriz M.; Szupiany, Ricardo N.; Gallo, Marcos N.

    2017-09-01

    The ability to predict the sediment and nutrient circulation within estuarine waters is of significant economic and ecological importance. In these complex systems, flocculation is a dynamically active process that is directly affected by the prevalent environmental conditions. Consequently, the floc properties continuously change, which greatly complicates the characterisation of the suspended particle matter (SPM). In the present study, three different techniques are combined in a stratified estuary under quiet weather conditions and with a low river discharge to search for a solution to this problem. The challenge is to obtain the concentration, size and flux of suspended elements through selected cross-sections using the method based on the simultaneous backscatter records of 1200 and 600 kHz ADCPs, isokinetic sampling data and LISST-25X measurements. The two-ADCP method is highly effective for determining the SPM size distributions in a non-intrusive way. The isokinetic sampling and the LISST-25X diffractometer offer point measurements at specific depths, which are especially useful for calibrating the ADCP backscatter intensity as a function of the SPM concentration and size, and providing complementary information on the sites where acoustic records are not available. Limitations and potentials of the techniques applied are discussed.

  14. Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures.

    Science.gov (United States)

    Addai, Emmanuel Kwasi; Gabel, Dieter; Krause, Ulrich

    2016-04-15

    The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Assessments of lake profiling on temperature, Total Suspended ...

    African Journals Online (AJOL)

    Interpolation were performed on temperature, total suspended solid (TSS) and turbidity (TUR) based on in-situ and ex-situ analyses according to the correlation matrix and linear regression at 14 different depths for the Chomor River and Mahadir Island. The result showed outlet significantly decreased over depth caused the ...

  16. Discrete Dynamics of Nanoparticle Channelling in Suspended Graphene

    DEFF Research Database (Denmark)

    Booth, Tim; Pizzocchero, Filippo; Andersen, Henrik

    2011-01-01

    We have observed a previously undescribed stepwise oxidation of mono- and few layer suspended graphene by silver nanoparticles in situ at subnanometer scale in an environmental transmission electron microscope. Over the range of 600–850 K, we observe crystallographically oriented channelling...

  17. Turbidity-controlled sampling for suspended sediment load estimation

    Science.gov (United States)

    Jack Lewis

    2003-01-01

    Abstract - Automated data collection is essential to effectively measure suspended sediment loads in storm events, particularly in small basins. Continuous turbidity measurements can be used, along with discharge, in an automated system that makes real-time sampling decisions to facilitate sediment load estimation. The Turbidity Threshold Sampling method distributes...

  18. Nature of suspended particulate matter and concentrations of heavy ...

    African Journals Online (AJOL)

    The concentrations of metals in bottom sediment in the Tanzanian waters of Lake Victoria and the nature of suspended particulate matter (SPM) were analysed. The objective of the study was to compare levels of metals in sediment from different locations and to establish their sources. Metal concentrations were higher in ...

  19. Comparison of Suspended Solid Separation in Advanced Storm Overflow Structures

    DEFF Research Database (Denmark)

    Larsen, Torben; Sørensen, Morten Steen

    1990-01-01

    This paper describes a laboratory investigation of the separation of suspended solids in a circular weir overflow and a vortex separator. The basic idea is to evaluate the efficiency of a vortical flow in the overflow chamber, and to compare these results with other overflow structures....

  20. Reduction in density of suspended - sediment - laden natural waters

    Digital Repository Service at National Institute of Oceanography (India)

    Joseph, A.; Desa, E.; Desa, E.; Smith, D.; Peshwe, V.B.; VijayKumar, K.; Desa, J.A.E.

    to 0.4% - 4.5%) that of the density of the same water without suspended sediment. Teh values of peff in a given site differed from one tidal cycle to another (approx equal to 1.9%). These values varied slightly (less than 0.8%) from mid-tide to slack...

  1. A suspended sediment yield predictive equation for river basins in ...

    African Journals Online (AJOL)

    The fit was found to be better than those relating mean annual specific suspended sediment yield to basin area or runoff only. Since many stream gauging stations in the country have no records on fluvial sediment, the empirical equation can be used to obtain preliminary estimates of expected sediment load of streams for ...

  2. Geochemistry of suspended and settling solids in two freshwater lakes.

    NARCIS (Netherlands)

    Koelmans, A.A.

    1998-01-01

    This study describes the 1987–1992 time variationof the bulk chemical composition, levels of heavymetals, arsenic, nitrogen and phosporous insuspended and settling solids in Lake Volkerak andLake Zoom (The Netherlands). Suspended and setlingsolids were collected with continuous flowcentrifuges and

  3. Opportunities Suspended: The Disparate Impact of Disciplinary Exclusion from School

    Science.gov (United States)

    Losen, Daniel J.; Gillespie, Jonathan

    2012-01-01

    Well over three million children, K-12, are estimated to have lost instructional "seat time" in 2009-2010 because they were suspended from school, often with no guarantee of adult supervision outside the school. That's about the number of children it would take to fill every seat in every major league baseball park and every NFL stadium…

  4. Microscopic characterisation of suspended graphene grown by chemical vapour deposition

    NARCIS (Netherlands)

    Bignardi, L.; Dorp, W.F. van; Gottardi, S.; Ivashenko, O.; Dudin, P.; Barinov, A.; de Hosson, J.T.M.; Stöhr, M.; Rudolf, P.

    2013-01-01

    We present a multi-technique characterisation of graphene grown by chemical vapour deposition (CVD) and thereafter transferred to and suspended on a grid for transmission electron microscopy (TEM). The properties of the electronic band structure are investigated by angle-resolved photoelectron

  5. Suspended Education Department Official Had Approved Waiver for Former Employer

    Science.gov (United States)

    Basken, Paul

    2007-01-01

    Matteo Fontana, the student-aid official in the U.S. Department of Education who was suspended last month in an ethics case, issued a controversial high-stakes legal ruling in 2004 that benefited his former employer, Sallie Mae, on the day before the nation's top student lender completed its transition from a government-founded lender into a…

  6. Evaluation of the Suspending Properties of the Coprecipitate of ...

    African Journals Online (AJOL)

    The suspending ability of the different ratios was evaluated in magnesium trisilicate suspension, and compared with a suspension prepared with Compound Tragacanth Powder BP (CTP) as well as a commercially available magnesium trisilicate suspension (MTS). The parameters tested were sedimentation rate, flow rate, ...

  7. Evaluation of the suspending properties of Cola acuminata gum on ...

    African Journals Online (AJOL)

    Calamine suspensions were formulated with CAG between the concentration range of 1 – 4 % w/v and compared with suspensions formulated with two standard suspending agents (tragacanth and acacia gums). Sedimentation volume, flow rate, rheology and redispersibility were used as evaluating parameters.

  8. Turbidity threshold sampling for suspended sediment load estimation

    Science.gov (United States)

    Jack Lewis; Rand Eads

    2001-01-01

    Abstract - The paper discusses an automated procedure for measuring turbidity and sampling suspended sediment. The basic equipment consists of a programmable data logger, an in situ turbidimeter, a pumping sampler, and a stage-measuring device. The data logger program employs turbidity to govern sample collection during each transport event. Mounting configurations and...

  9. Continuous measurements of suspended sediment loads using dual frequency acoustic Doppler profile signals

    Science.gov (United States)

    Antonini, Alessandro; Guerrero, Massimo; Rüther, Nils; Stokseth, Siri

    2016-04-01

    A huge thread to Hydropower plants (HPP) is incoming sediments in suspension from the rivers upstream. The sediments settle in the reservoir and reduce the effective head as well as the volume and reduce consequently the lifetime of the reservoir. In addition are the fine sediments causing severe damages to turbines and infrastructure of a HPP. For estimating the amount of in-coming sediments in suspension and the consequent planning of efficient counter measures, it is essential to monitor the rivers within the catchment of the HPP for suspended sediments. This work is considerably time consuming and requires highly educated personnel and is therefore expensive. Surrogate-indirect methods using acoustic and optic devices have bee developed since the last decades that may be efficiently applied for the continuous monitoring of suspended sediment loads. The presented study proposes therefore to establish a research station at a cross section of a river which is the main tributary to a reservoir of a HPP and equip this station with surrogate as well as with common method of measuring suspended load concentrations and related flow discharge and level. The logger at the research station delivers data automatically to a server. Therefore it is ensured that also large flood events are covered. Data during flood are of high interest to the HPP planners since they carried the most part of the sediment load in a hydrological year. Theses peaks can hardly be measured with common measurement methods. Preliminary results of the wet season 2015/2016 are presented. The data gives insight in the applicable range, in terms of scattering particles concentration-average size and corresponding flow discharge and level, eventually enabling the study of suspended sediment load-water flow correlations during peak events. This work is carried out as part of a larger research project on sustainable hydro power plants exposed to high sediment yield, SediPASS. SediPASS is funded by the

  10. An analysis of bedload and suspended load interactions

    Science.gov (United States)

    Recking, alain; Navratil, Oldrich

    2013-04-01

    Several approaches were used to develop suspension equations. It includes semi-theoretical equations based on the convection diffusion equation (Einstein 1950; Van Rijn 1984; Camenen and Larson 2008; Julien 2010), semi-empirical tools based on energy concept (Velikanov 1954; Bagnold 1966), empirical adjustments (Prosser and Rusttomji 2000). One essential characteristic of all these equations is that most of them were developed by considering continuity between bedload and suspended load, and that the partitioning between these two modes of transport evolves progressively with increasing shear stress, which is the case for fine bed materials. The use of these equations is thus likely to be welcome in estuaries or lowland sandy rivers, but may be questionable in gravel-bed rivers and headwater streams where the bed is usually structured vertically and fine sediments potentially contributing to suspension are stored under a poorly mobile surface armour comprising coarse sediments. Thus one question this work aimed to answer is does the presence of an armour at the bed surface influence suspended load? This was investigated through a large field data set comprising instantaneous measurements of both bedload and suspension. We also considered the river characteristics, distinguishing between lowland rivers, gravel bed rivers and headwater streams. The results showed that a correlation exist between bedload and suspension for lowland and gravel bed rivers. This suggests that in gravel bed rivers a large part of the suspended load is fed by subsurface material, and depends on the remobilization of the surface material. No correlation was observed for head water streams where the sediment production is more likely related to hillslope processes. These results were used with a bedload transport equation for proposing a method for suspended load estimate. The method is rough, but especially for gravel bed rivers, it predicts suspended load reasonably well when compared to

  11. Phenomenology of U(1){sub F} extension of inert-doublet model with exotic scalars and leptons

    Energy Technology Data Exchange (ETDEWEB)

    Dhargyal, Lobsang [Harish-Chandra Research Institute, HBNI, Allahabad (India)

    2018-02-15

    In this work we will extend the inert-doublet model (IDM) by adding a new U(1){sub F} gauge symmetry to it, under which, a Z{sub 2} even scalar (φ{sub 2}) and Z{sub 2} odd right handed component of two exotic charged leptons (F{sub eR}, F{sub μR}), are charged. We also add one Z{sub 2} even real scalar (φ{sub 1}) and one complex scalar (φ), three neutral Majorana right handed fermions (N{sub 1}, N{sub 2}, N{sub 3}), two left handed components of the exotic charged leptons (F{sub eL}, F{sub μL}) as well as F{sub τ} are all odd under the Z{sub 2}, all of which are not charged under the U(1){sub F}. With these new particles added to the IDM, we have a model which can give two scalar DM candidates, together they can explain the present DM relic density as well as the muon (g-2) anomaly simultaneously. Also in this model the neutrino masses are generated at one loop level. One of the most peculiar feature of this model is that non-trivial solution to the axial gauge anomaly free conditions lead to the prediction of a stable very heavy partner to the electron (F{sub e}), whose present collider limit (13 TeV LHC) on its mass should be around m{sub F{sub e}} ≥ few TeV. (orig.)

  12. Kinetics of thermal decomposition of aluminium hydride: I-non-isothermal decomposition under vacuum and in inert atmosphere (argon)

    International Nuclear Information System (INIS)

    Ismail, I.M.K.; Hawkins, T.

    2005-01-01

    Recently, interest in aluminium hydride (alane) as a rocket propulsion ingredient has been renewed due to improvements in its manufacturing process and an increase in thermal stability. When alane is added to solid propellant formulations, rocket performance is enhanced and the specific impulse increases. Preliminary work was performed at AFRL on the characterization and evaluation of two alane samples. Decomposition kinetics were determined from gravimetric TGA data and volumetric vacuum thermal stability (VTS) results. Chemical analysis showed the samples had 88.30% (by weight) aluminium and 9.96% hydrogen. The average density, as measured by helium pycnometery, was 1.486 g/cc. Scanning electron microscopy showed that the particles were mostly composed of sharp edged crystallographic polyhedral such as simple cubes, cubic octahedrons and hexagonal prisms. Thermogravimetric analysis was utilized to investigate the decomposition kinetics of alane in argon atmosphere and to shed light on the mechanism of alane decomposition. Two kinetic models were successfully developed and used to propose a mechanism for the complete decomposition of alane and to predict its shelf-life during storage. Alane decomposes in two steps. The slowest (rate-determining) step is solely controlled by solid state nucleation of aluminium crystals; the fastest step is due to growth of the crystals. Thus, during decomposition, hydrogen gas is liberated and the initial polyhedral AlH 3 crystals yield a final mix of amorphous aluminium and aluminium crystals. After establishing the kinetic model, prediction calculations indicated that alane can be stored in inert atmosphere at temperatures below 10 deg. C for long periods of time (e.g., 15 years) without significant decomposition. After 15 years of storage, the kinetic model predicts ∼0.1% decomposition, but storage at higher temperatures (e.g. 30 deg. C) is not recommended

  13. Environmental toxicology: Acute effects of suspended particulate matter (dust on hematological indices of albino rats

    Directory of Open Access Journals (Sweden)

    V.O. Ogugbuaja

    2004-12-01

    Full Text Available The elemental contents of suspended particulate matter (dust samples from Maiduguri, Nigeria, were determined which showed appreciably high levels for especially Pb, Fe, Cu, Zn, K, Ca, and. Na. Wister albino rats were exposed to graded doses of phosphate buffered saline carried dust particles. The hematological indices of the exposed rats were examined on days 10, 20, 30, and 60 post administrations. White blood cell, red blood cell and hemoglobin counts peaked between days 20 and 30. This observation was markedly so for the higher doses, 1000 and 2000 mg/kg, in contrast to the 500 mg/kg dose. The platelet count however indicated a gradual increase within the study period. Observed changes for these indices from the control values were found significant at 99% confidence level. Possible inhalatory problems are thus anticipated from prolonged accumulation of the dust in the respiratory system.

  14. Chemical composition shape form and size of suspended solids in the atmosphere carried by rain water

    International Nuclear Information System (INIS)

    Iturbe G, J.L.; Lopez M, B.E.; Torre O, J. De la

    2001-01-01

    The interest of this work is to know about shape form, size and chemical composition of the suspended solids in the atmosphere of Toluca city and which are carried by the rains. The harvest of the samples was carried out during january to november 1999. The separation of the particulate matter from the rain water was realized through centrifugation. The solids were analysed by Scanning Electron Microscopy to know the shape form and size and the chemical composition was determined by X-ray dispersive energy in general form and of some particles individually analysed. The p H was measured to the solutions and the quantification of some dissolved ions by the Icp technique was realized. The results of the solids showed C, O, Na, Mg, Al, Si, S, P, K, Ca, Ti and Fe. Moreover they present sizes which varying from a ten of nanometers until some tens of microns. (Author)

  15. Optical Characterization of the Interaction of Mercury with Nanoparticulate Gold Suspended in Solution

    Directory of Open Access Journals (Sweden)

    Kevin SCALLAN

    2007-11-01

    Full Text Available We have demonstrated that the surface plasmon resonance (SPR wavelength of gold nanoparticles suspended in solution can be modified by exposure to elemental mercury at sub parts per million (ppm concentrations in nitrogen. Ultraviolet-visible (UV-vis absorption spectroscopy was used to monitor the wavelength and maximum absorbance of the colloidal solution during and after the exposure process. Transmission electron microscopy (TEM images revealed modifications to the morphology of the particles (size, shape, and extent of aggregation. The results show that the SPR wavelength is blue-shifted and the absorbance is increased with exposure time. After the exposure, the spectra were observed to relax toward their original position suggesting that the detection medium is regenerative.

  16. Overview of selected surrogate technologies for high-temporal resolution suspended-sediment monitoring

    Science.gov (United States)

    Gray, John R.; Gartner, Jeffrey W.

    2010-01-01

    Traditional methods for characterizing selected properties of suspended sediments in rivers are being augmented and in some cases replaced by cost-effective surrogate instruments and methods that produce a temporally dense time series of quantifiably accurate data for use primarily in sediment-flux computations. Turbidity is the most common such surrogate technology, and the first to be sanctioned by the U.S. Geological Survey for use in producing data used in concert with water-discharge data to compute sediment concentrations and fluxes for storage in the National Water Information System. Other technologies, including laser-diffraction, digital photo-optic, acoustic-attenuation and backscatter, and pressure-difference techniques are being evaluated for producing reliable sediment concentration and, in some cases, particle-size distribution data. Each technology addresses a niche for sediment monitoring. Their performances range from compelling to disappointing. Some of these technologies have the potential to revolutionize fluvial-sediment data collection, analysis, and availability.

  17. Stochastic modeling of total suspended solids (TSS) in urban areas during rain events.

    Science.gov (United States)

    Rossi, Luca; Krejci, Vladimir; Rauch, Wolfgang; Kreikenbaum, Simon; Fankhauser, Rolf; Gujer, Willi

    2005-10-01

    The load of total suspended solids (TSS) is one of the most important parameters for evaluating wet-weather pollution in urban sanitation systems. In fact, pollutants such as heavy metals, polycyclic aromatic hydrocarbons (PAHs), phosphorous and organic compounds are adsorbed onto these particles so that a high TSS load indicates the potential impact on the receiving waters. In this paper, a stochastic model is proposed to estimate the TSS load and its dynamics during rain events. Information on the various simulated processes was extracted from different studies of TSS in urban areas. The model thus predicts the probability of TSS loads arising from combined sewer overflows (CSOs) in combined sewer systems as well as from stormwater in separate sewer systems in addition to the amount of TSS retained in treatment devices in both sewer systems. The results of this TSS model illustrate the potential of the stochastic modeling approach for assessing environmental problems.

  18. Radionuclide contents in suspended sediments in relation to flood types in the lower Rhone River

    International Nuclear Information System (INIS)

    Zebracki, Mathilde; Eyrolle-Boyer, Frederique; Antonelli, Christelle; Boullier, Vincent; De Vismes-Ott, Anne; Cagnat, Xavier

    2013-01-01

    The aim of this work was to study the influence of watershed heterogeneity on the radionuclide contents of suspended particulate matter (SPM) in a large Mediterranean river. As the Rhone River catchment is characterized by a high climatic and geological heterogeneity, floods can be distinguished according to their geographic origins. Long-term time series of particles associated with radionuclides acquired in the framework of radiological surveillance provide a relevant dataset to investigate the variability of radionuclide contents. The SPM exported during Mediterranean floods differ from other floods as they display higher 238 U and 232 Th contents and the lowest activity ratio 137 Cs/ (239+240) Pu; these properties could be related to bedrock type and erosion process characteristics and/or to source term differentiation. (authors)

  19. Impact of airway gas exchange on the multiple inert gas elimination technique: theory.

    Science.gov (United States)

    Anderson, Joseph C; Hlastala, Michael P

    2010-03-01

    The multiple inert gas elimination technique (MIGET) provides a method for estimating alveolar gas exchange efficiency. Six soluble inert gases are infused into a peripheral vein. Measurements of these gases in breath, arterial blood, and venous blood are interpreted using a mathematical model of alveolar gas exchange (MIGET model) that neglects airway gas exchange. A mathematical model describing airway and alveolar gas exchange predicts that two of these gases, ether and acetone, exchange primarily within the airways. To determine the effect of airway gas exchange on the MIGET, we selected two additional gases, toluene and m-dichlorobenzene, that have the same blood solubility as ether and acetone and minimize airway gas exchange via their low water solubility. The airway-alveolar gas exchange model simulated the exchange of toluene, m-dichlorobenzene, and the six MIGET gases under multiple conditions of alveolar ventilation-to-perfusion, VA/Q, heterogeneity. We increased the importance of airway gas exchange by changing bronchial blood flow, Qbr. From these simulations, we calculated the excretion and retention of the eight inert gases and divided the results into two groups: (1) the standard MIGET gases which included acetone and ether and (2) the modified MIGET gases which included toluene and m-dichlorobenzene. The MIGET mathematical model predicted distributions of ventilation and perfusion for each grouping of gases and multiple perturbations of VA/Q and Qbr. Using the modified MIGET gases, MIGET predicted a smaller dead space fraction, greater mean VA, greater log(SDVA), and more closely matched the imposed VA distribution than that using the standard MIGET gases. Perfusion distributions were relatively unaffected.

  20. Compound forming extractants, solvating solvents and inert solvents IUPAC chemical data series

    CERN Document Server

    Marcus, Y; Kertes, A S

    2013-01-01

    Equilibrium Constants of Liquid-Liquid Distribution Reactions, Part III: Compound Forming Extractants, Solvating Solvents, and Inert Solvents focuses on the compilation of equilibrium constants of various compounds, such as acids, ions, salts, and aqueous solutions. The manuscript presents tables that show the distribution reactions of carboxylic and sulfonic acid extractants and their dimerization and other reactions in the organic phase and extraction reactions of metal ions from aqueous solutions. The book also states that the inorganic anions in these solutions are irrelevant, since they d

  1. Investigation of the Hall MHD channel operating with the ionized instable plasma of inert gases

    International Nuclear Information System (INIS)

    Vasi'leva, R.V.; D'yakova, E.A.; Erofeev, A.V.; Zuev, A.D.; Lapushkina, T.A.; Markhotok, A.A.

    1997-01-01

    Possibility of applying ionization-instable plasma of pure inert gases as perspective working substance for closed-cycle MHD generators is studied. The experiment was produced in the model of the disk Hall MHD channel. The ionized gas flux was produced in a shock tube. Xenon was used as a working substance. Gas pressure, flux velocity, electron concentration and temperature, azimuthal current density, potential distribution in the channel and near-electrode voltage drop values were measured in the experiment. Volt-ampere characteristics were taken by various indices of magnetic field and load resistance

  2. Innovative inert matrix-thoria fuels for in-reactor plutonium disposition

    International Nuclear Information System (INIS)

    Vettraino, F.; Padovani, E.; Luzzi, L.; Lombardi, C.; Thoresen, H.; Oberlander, B.; Iversen, G.; Espeland, M.

    1999-01-01

    The present leading option for plutonium disposition, either civilian or weapons Pu, is to burn it in LWRs after having converted it to MOX fuel. However, among the possible types of fuel which can be envisaged to burn plutonium in LWRs, innovative U-free fuels such as inert matrix and thoria fuel are novel concept in view of a more effective and ultimate solution from both security and safety standpoint. Inert matrix fuel is an non-fertile oxide fuel consisting of PuO 2 , either weapon-grade or reactor-grade, diluted in inert oxides such as for ex. stabilized ZrO 2 or MgAl 2 O 4 , its primary advantage consisting in no-production of new plutonium during irradiation, because it does not contain uranium (U-free fuel) whose U-238 isotope is the departure nuclide for breeding Pu-239. Some thoria addition in the matrix (thoria-doped fuel) may be required for coping with reactivity feedback needs. The full thoria-plutonia fuel though still a U-free variant cannot be defined non-fertile any more because the U-233 generation. The advantage of such a fuel option consisting basically on a remarkable already existing technological background and a potential acceleration in getting rid of the Pu stocks. All U-free fuels are envisaged to be operated under a once-through cycle scheme being the spent fuel outlooked to be sent directly to the final disposal in deep geological formations without requiring any further reprocessing treatment, thanks to the quality-poor residual Pu and a very high chemical stability under the current fuel reprocessing techniques. Besides, inert matrix-thoria fuel technology is suitable for in-reactor MAs transmutation. An additional interest in Th containing fuel refers to applicability in ADS, the innovative accelerated driven subcritical systems, specifically aimed at plutonium, minor actnides and long lived fission products transmutation in a Th-fuel cycle scheme which enables to avoid generations of new TRUs. A first common irradiation experiment

  3. Allowable spent LWR fuel storage temperatures in inert gases, nitrogen, and air

    International Nuclear Information System (INIS)

    Gilbert, E.R.; Cunningham, M.E.; Simonen, E.P.; Thomas, L.E.; Campbell, T.K.; Barnhart, D.M.

    1990-01-01

    Spent fuel in inert dry storage is now a reality in the US; recommended maximum temperature-time conditions are specified in an IBM PC-compatible code. However, spent fuel cannot yet be stored in air because the data and theory needed for predicting allowable temperatures are still being developed. Tests to determine the behavior of spent UO 2 fragments and breached rod specimens in air are providing data that will be used to determine the temperatures that can be allowed for fuel stored in air. 13 refs., 5 figs

  4. Optimal dual-fuel propulsion for minimum inert weight or minimum fuel cost

    Science.gov (United States)

    Martin, J. A.

    1973-01-01

    An analytical investigation of single-stage vehicles with multiple propulsion phases has been conducted with the phasing optimized to minimize a general cost function. Some results are presented for linearized sizing relationships which indicate that single-stage-to-orbit, dual-fuel rocket vehicles can have lower inert weight than similar single-fuel rocket vehicles and that the advantage of dual-fuel vehicles can be increased if a dual-fuel engine is developed. The results also indicate that the optimum split can vary considerably with the choice of cost function to be minimized.

  5. A method for making an inert porous electrode for a chemical current source

    Energy Technology Data Exchange (ETDEWEB)

    Ksenzhek, O.S.; Litvinova, V.I.; Martynenko, T.L.; Raykhelson, L.B.; Shembel, Ye.M.; Sokolov, L.A.

    1983-01-01

    A method is proposed for making an inert, porous electrode for chemical current sources (KhIT) with a nonaqueous electrolyte on the basis of aprotonic solvents and an active cathode substance which is dissolved in the electrolyte. The method includes preparing an electrode mass from the starting material and subsequent formation of the electrode. To increase the energy capacity, after formation, the electrode is subjected to electrochemical anode polarization to potentials which correspond to the potential of electrochemical breakdown of the background electrolyte.

  6. Determination of hydrogen in uranium-niobium-zirconium alloy by inert-gas fusion

    International Nuclear Information System (INIS)

    Carden, W.F.

    1979-12-01

    An improved method has been developed using inert-gas fusion for determining the hydrogen content in uranium-niobium-zirconium (U-7.5Nb-2.5Zr) alloy. The method is applicable to concentrations of hydrogen ranging from 1 to 250 micrograms per gram and may be adjusted for analysis of greater hydrogen concentrations. Hydrogen is determined using a hydrogen determinator. The limit of error for a single determination at the 95%-confidence level (at the 3.7-μg/g-hydrogen level) is +-1.4 micrograms per gram hydrogen

  7. Modelling the transient behaviour of pulsed current tungsten-inert-gas weldpools

    Science.gov (United States)

    Wu, C. S.; Zheng, W.; Wu, L.

    1999-01-01

    A three-dimensional model is established to simulate the pulsed current tungsten-inert-gas (TIG) welding process. The goal is to analyse the cyclic variation of fluid flow and heat transfer in weldpools under periodic arc heat input. To this end, an algorithm, which is capable of handling the transience, nonlinearity, multiphase and strong coupling encountered in this work, is developed. The numerical simulations demonstrate the transient behaviour of weldpools under pulsed current. Experimental data are compared with numerical results to show the effectiveness of the developed model.

  8. Using fumarolic inert gas composition to investigate magma dynamics at Campi Flegrei (Italy)

    Science.gov (United States)

    Chiodini, G.; Caliro, S.; Paonita, A.; Cardellini, C.

    2013-12-01

    Since 2000 the Campi Flegrei caldera sited in Neapolitan area (Italy), has showed signs of reactivation, marked by ground uplift, seismic activity, compositional variations of fumarolic effluents from La Solfatara, an increase of the fumarolic activity as well as of soil CO2 fluxes. Comparing long time series of geochemical signals with ground deformation and seismicity, we show that these changes are at least partially caused by repeated injections of magmatic fluid into the hydrothermal system. The frequency of these degassing episodes has increased in the last years, causing pulsed uplift episodes and swarms of low magnitude earthquakes. We focus here in the inert gas species (CO2-He-Ar-N2) of Solfatara fumaroles which displayed in the time spectacular and persistent variation trends affecting all the monitored vents. The observed variations, which include a continuous decrease of both N2/He and N2/CO2 ratios since 1985, paralleled by an increase of He/CO2, can not be explained neither with changes in processes of boiling-condensation in the local hydrothermal system nor with changes in the mixing proportions between a magmatic vapour and hydrothermal fluids. Consequently we investigated the possibility that the trends of inert gas species are governed by changes in the conditions controlling magma degassing at depth. We applied a magma degassing model, with the most recent updates for inert gas solubilities, after to have included petrologic constraints from the ranges of melt composition and reservoir pressure at Campi Flegrei. The model simulations for mafic melts (trachybasalt and shoshonite) show a surprising agreement with the measured data. Both decompressive degassing of an ascending magma and mixing between magmatic fluids exsolved at various levels along the ascent path can explain the long-time geochemical changes. Our work highlights that, in caldera systems where the presence of hydrothermal aquifers commonly masks the magmatic signature of reactive

  9. Regenerable mixed copper-iron-inert support oxygen carriers for solid fuel chemical looping combustion process

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardane, Ranjani V.; Tian, Hanjing

    2016-12-20

    The disclosure provides an oxygen carrier for a chemical looping cycle, such as the chemical looping combustion of solid carbonaceous fuels, such as coal, coke, coal and biomass char, and the like. The oxygen carrier is comprised of at least 24 weight % (wt %) CuO, at least 10 wt % Fe2O3, and an inert support, and is typically a calcine. The oxygen carrier exhibits a CuO crystalline structure and an absence of iron oxide crystalline structures under XRD crystallography, and provides an improved and sustained combustion reactivity in the temperature range of 600.degree. C.-1000.degree. C. particularly for solid fuels such as carbon and coal.

  10. Interactions Between Suspended Kaolinite Deposition and Hyporheic Exchange Flux Under Losing and Gaining Flow Conditions

    Science.gov (United States)

    Fox, Aryeh; Packman, Aaron I.; Boano, Fulvio; Phillips, Colin B.; Arnon, Shai

    2018-05-01

    Fine particle deposition and streambed clogging affect many ecological and biogeochemical processes, but little is known about the effects of groundwater flow into and out of rivers on clogging. We evaluated the effects of losing and gaining flow on the deposition of suspended kaolinite clay particles in a sand streambed and the resulting changes in rates and patterns of hyporheic exchange flux (HEF). Observations of clay deposition from the water column, clay accumulation in the streambed sediments, and water exchange with the bed demonstrated that clay deposition in the bed substantially reduced both HEF and the size of the hyporheic zone. Clay deposition and HEF were strongly coupled, leading to rapid clogging in areas of water and clay influx into the bed. Local clogging diverted exchanged water laterally, producing clay deposit layers that reduced vertical hyporheic flow and favored horizontal flow. Under gaining conditions, HEF was spatially constrained by upwelling water, which focused clay deposition in a small region on the upstream side of each bed form. Because the area of inflow into the bed was smallest under gaining conditions, local clogging required less clay mass under gaining conditions than neutral or losing conditions. These results indicate that losing and gaining flow conditions need to be considered in assessments of hyporheic exchange, fine particle dynamics in streams, and streambed clogging and restoration.

  11. Acoustic interaction forces between small particles in an ideal fluid

    DEFF Research Database (Denmark)

    Silva, Glauber T.; Bruus, Henrik

    2014-01-01

    We present a theoretical expression for the acoustic interaction force between small spherical particles suspended in an ideal fluid exposed to an external acoustic wave. The acoustic interaction force is the part of the acoustic radiation force on one given particle involving the scattered waves...... from the other particles. The particles, either compressible liquid droplets or elastic microspheres, are considered to be much smaller than the acoustic wavelength. In this so-called Rayleigh limit, the acoustic interaction forces between the particles are well approximated by gradients of pair...

  12. Temperature signal in suspended sediment export from an Alpine catchment

    Directory of Open Access Journals (Sweden)

    A. Costa

    2018-01-01

    Full Text Available Suspended sediment export from large Alpine catchments ( >  1000 km2 over decadal timescales is sensitive to a number of factors, including long-term variations in climate, the activation–deactivation of different sediment sources (proglacial areas, hillslopes, etc., transport through the fluvial system, and potential anthropogenic impacts on the sediment flux (e.g. through impoundments and flow regulation. Here, we report on a marked increase in suspended sediment concentrations observed near the outlet of the upper Rhône River Basin in the mid-1980s. This increase coincides with a statistically significant step-like increase in basin-wide mean air temperature. We explore the possible explanations of the suspended sediment rise in terms of changes in water discharge (transport capacity, and the activation of different potential sources of fine sediment (sediment supply in the catchment by hydroclimatic forcing. Time series of precipitation and temperature-driven snowmelt, snow cover, and ice melt simulated with a spatially distributed degree-day model, together with erosive rainfall on snow-free surfaces, are tested to explore possible reasons for the rise in suspended sediment concentration. We show that the abrupt change in air temperature reduced snow cover and the contribution of snowmelt, and enhanced ice melt. The results of statistical tests show that the onset of increased ice melt was likely to play a dominant role in the suspended sediment concentration rise in the mid-1980s. Temperature-driven enhanced melting of glaciers, which cover about 10 % of the catchment surface, can increase suspended sediment yields through an increased contribution of sediment-rich glacial meltwater, increased sediment availability due to glacier recession, and increased runoff from sediment-rich proglacial areas. The reduced extent and duration of snow cover in the catchment are also potential contributors to the rise in suspended sediment

  13. Discriminating silt-and-clay from suspended-sand in rivers using side-looking acoustic profilers

    Science.gov (United States)

    Wright, Scott A.; Topping, David J.; Williams, Cory A.

    2010-01-01

    techniques rely on measurements of ancillary properties that correlate with suspended-sediment concentration and particle size and thus require the collection of traditional samples for calibration. Through in situ deployments, these methods can provide the high temporal resolution that cannot be achieved through traditional sampling. Here we focus on the evaluation of acoustic profiling techniques (e.g. acoustic-Doppler sideways-looking profilers, or ADPs). One major advantage of acoustic profiling is the ability to concurrently measure water velocity (using Doppler-shift methods) and suspended-sediment concentration such that suspended-sediment flux can be directly computed using data from a single instrument. Acoustic-Doppler profilers have become popular for measuring water velocity and discharge in rivers, through both moving-boat operations and from fixed deployments such as bank-mounted sideways-looking instruments (Hirsch and Costa, 2004, Muste et al., 2007). The method presented herein is most suited to sideways-looking applications as a complement to the "index velocity" technique, whereby an index velocity from a sideways-looking instrument is related to the cross-section average velocity (determined from moving-boat discharge measurements) as a means for developing a continuous water-discharge record (Ruhl and Simpson, 2005). Topping et al. (2007) presented a method for discriminating silt-and-clay from suspended sand, using single frequency ADPs. This method takes advantage of the relations among acoustic backscatter, sediment-induced acoustic attenuation, suspended-sediment concentration (SSC), and particle size distribution (PSD). Backscatter is the amount of sound scattered back and received at the transducer while sediment-induced attenuation is the amount of sound scattered in other directions and absorbed by the sediment particles. Both of these parameters can be measured with an ADP, and their different dependencies on SSC and PSD allow for the

  14. Rare particles

    International Nuclear Information System (INIS)

    Kutschera, W.

    1984-01-01

    The use of Accelerator Mass Spectrometry (AMS) to search for hypothetical particles and known particles of rare processes is discussed. The hypothetical particles considered include fractionally charged particles, anomalously heavy isotopes, and superheavy elements. The known particles produced in rare processes discussed include doubly-charged negative ions, counting neutrino-produced atoms in detectors for solar neutrino detection, and the spontaneous emission of 14 C from 223 Ra. 35 references

  15. USING TURBIDITY DATA TO PREDICT SUSPENDED SEDIMENT CONCENTRATIONS: POSSIBILITIES, LIMITATIONS, AND PITFALLS

    Science.gov (United States)

    This talk will look at the relationships between turbidity and suspended sediment concentrations in a variety of geographic areas, geomorphic river types, and river sizes; and attempt to give guidance on using existing turbidity data to predict suspended sediment concentrations.

  16. Seasonal changes in suspended sediment load in the Gauthami-Godavari Estuary

    Digital Repository Service at National Institute of Oceanography (India)

    Reddy, N.P.C.; Rao, B.P.; Rao, K.M.; Rao, V.S.

    Studies carried out on suspended matter characteristics of the the Gautami Godavari Estuary revealed that the concentration of suspended matter (CSM) during southwest monsoon influenced mainly by the increased run off at both Neelarevu and Vrudha...

  17. Impact of sound attenuation by suspended sediment on ADCP backscatter calibrations

    NARCIS (Netherlands)

    Sassi, M.G.; Hoitink, A.J.F.; Vermeulen, B.

    2012-01-01

    Although designed for velocity measurements, acoustic Doppler current profilers (ADCPs) are widely being used to monitor suspended particulate matter in rivers and in marine environments. To quantify mass concentrations of suspended matter, ADCP backscatter is generally calibrated with in situ

  18. Design, analysis and control of cable-suspended parallel robots and its applications

    CERN Document Server

    Zi, Bin

    2017-01-01

    This book provides an essential overview of the authors’ work in the field of cable-suspended parallel robots, focusing on innovative design, mechanics, control, development and applications. It presents and analyzes several typical mechanical architectures of cable-suspended parallel robots in practical applications, including the feed cable-suspended structure for super antennae, hybrid-driven-based cable-suspended parallel robots, and cooperative cable parallel manipulators for multiple mobile cranes. It also addresses the fundamental mechanics of cable-suspended parallel robots on the basis of their typical applications, including the kinematics, dynamics and trajectory tracking control of the feed cable-suspended structure for super antennae. In addition it proposes a novel hybrid-driven-based cable-suspended parallel robot that uses integrated mechanism design methods to improve the performance of traditional cable-suspended parallel robots. A comparative study on error and performance indices of hybr...

  19. Method for rapid particle size analysis by hydrosizing and nuclear sensing

    International Nuclear Information System (INIS)

    Daellenbach, C.B.; Mahan, W.M.

    1977-01-01

    A method and apparatus to practice the method for rapidly determining the size and mass distribution of a sample of randomly sized particles of a known total mass are described. A series of substantially identical hydrocyclones are connected by conduits to each other and to a temperature controlled water feed. By restricting the cross-sectional areas of these conduits to progressively smaller values, the slurry containing the sample particles is caused to increase its velocity as it moves from hydrocyclone to hydrocyclone. As described by the Stokesian theory which relates particle diameter and settling velocity, the largest sized particles are suspended in the closed apex of the first hydrocyclone with smaller sized particles, in given size ranges, being suspended in the next succeeding hydrocyclone's apexes. In this manner, the particles are separated into discrete fractional sizes with a residual slurry of the very smallest particles being discharged. Before the discrete fractions of particles are suspended in their hydrocyclone apexes, a combined photon source, like a gamma ray source, and detector are calibrated with the water temperature kept constant. When the suspension of particles takes place, an attenuation of the radiation from the source is observed at the detector. This attenuation can be related to the mass or weight of the discrete fractions of suspended particles. Electronic circuitry is used to indicate what this fractional mass or weight is as it relates to the total weight of the sample. 6 claims, 4 figs

  20. Resuspension and transport of suspended solids in Eurajoensalmi Bay. Final report of monitoring activities in 2009-2011

    International Nuclear Information System (INIS)

    Mykkanen, J.; Kiirikki, M.; Lindfors, A.

    2012-11-01

    The goal of monitoring activities carried out in Eurajoensalmi Bay was to indentify factors affecting dispersal of river waters and suspended solid matter in the estuary area. In addition to suspended solids load and dispersal of river water, also release of sedimented particles from the sea bed in resuspension was studied. River water quality and discharge as well as resuspension in Eurajoensalmi estuary area were monitored with Luode automatic monitoring stations equipped with water quality, water level, wave height and weather sensors. Dynamics of Eurajoensalmi estuary area was studied by installing profiling current meters (ADCP) and water quality sensors to the sea floor at the mouth of Eurajoensalmi. Spatial variation of surface water quality was monitored with a flow-through method from a moving vessel and manual profiling several times during the monitoring period. Collected data was processed and used in determining suspended solids balance of Eurajoensalmi Bay. The balance was determined by creating a regression model for water exchange and sediment flux over the cross section at the mouth of Eurajoensalmi. Regression model was created also to determine resuspension in Eurajoensalmi area. Sediment flux and resuspension were modeled using long term wind data from Kylmaepihlaja meteorological station as a variable to determine overall sediment balance of Eurajoensalmi