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Sample records for simulated cesium elution

  1. Small-Column Cesium Ion Exchange Elution Testing of Spherical Resorcinol-Formaldehyde

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Garrett N.; Russell, Renee L.; Peterson, Reid A.

    2011-10-21

    This report summarizes the work performed to evaluate multiple, cesium loading, and elution cycles for small columns containing SRF resin using a simple, high-level waste (HLW) simulant. Cesium ion exchange loading and elution curves were generated for a nominal 5 M Na, 2.4E-05 M Cs, 0.115 M Al loading solution traced with 134Cs followed by elution with variable HNO3 (0.02, 0.07, 0.15, 0.23, and 0.28 M) containing variable CsNO3 (5.0E-09, 5.0E-08, and 5.0E-07 M) and traced with 137Cs. The ion exchange system consisted of a pump, tubing, process solutions, and a single, small ({approx}15.7 mL) bed of SRF resin with a water-jacketed column for temperature-control. The columns were loaded with approximately 250 bed volumes (BVs) of feed solution at 45 C and at 1.5 to 12 BV per hour (0.15 to 1.2 cm/min). The columns were then eluted with 29+ BVs of HNO3 processed at 25 C and at 1.4 BV/h. The two independent tracers allowed analysis of the on-column cesium interaction between the loading and elution solutions. The objective of these tests was to improve the correlation between the spent resin cesium content and cesium leached out of the resin in subsequent loading cycles (cesium leakage) to help establish acid strength and purity requirements.

  2. Molecular dynamic simulation study of molten cesium

    Directory of Open Access Journals (Sweden)

    Yeganegi Saeid

    2017-01-01

    Full Text Available Molecular dynamics simulations were performed to study thermodynamics and structural properties of expanded caesium fluid. Internal pressure, radial distribution functions (RDFs, coordination numbers and diffusion coefficients have been calculated at temperature range 700–1600 K and pressure range 100–800 bar. We used the internal pressure to predict the metal–non-metal transition occurrence region. RDFs were calculated at wide ranges of temperature and pressure. The coordination numbers decrease and positions of the first peak of RDFs slightly increase as the temperature increases and pressure decreases. The calculated self-diffusion coefficients at various temperatures and pressures show no distinct boundary between Cs metallic fluid and its expanded fluid where it continuously increases with temperature.

  3. Caustic-Side Solvent Extraction: Prediction of Cesium Extraction from Actual Wastes and Actual Waste Simulants

    International Nuclear Information System (INIS)

    Delmau, L.H.; Haverlock, T.J.; Sloop, F.V. Jr.; Moyer, B.A.

    2003-01-01

    This report presents the work that followed the CSSX model development completed in FY2002. The developed cesium and potassium extraction model was based on extraction data obtained from simple aqueous media. It was tested to ensure the validity of the prediction for the cesium extraction from actual waste. Compositions of the actual tank waste were obtained from the Savannah River Site personnel and were used to prepare defined simulants and to predict cesium distribution ratios using the model. It was therefore possible to compare the cesium distribution ratios obtained from the actual waste, the simulant, and the predicted values. It was determined that the predicted values agree with the measured values for the simulants. Predicted values also agreed, with three exceptions, with measured values for the tank wastes. Discrepancies were attributed in part to the uncertainty in the cation/anion balance in the actual waste composition, but likely more so to the uncertainty in the potassium concentration in the waste, given the demonstrated large competing effect of this metal on cesium extraction. It was demonstrated that the upper limit for the potassium concentration in the feed ought to not exceed 0.05 M in order to maintain suitable cesium distribution ratios

  4. Oral factors affecting titanium elution and corrosion: an in vitro study using simulated body fluid.

    Directory of Open Access Journals (Sweden)

    Hideki Suito

    Full Text Available OBJECTIVES: Ti, which is biocompatible and resistant to corrosion, is widely used for dental implants, particularly in patients allergic to other materials. However, numerous studies have reported on Ti allergy and the in vitro corrosion of Ti. This study investigated the conditions that promote the elution of Ti ions from Ti implants. METHODS: Specimens of commercially pure Ti, pure nickel, a magnetic alloy, and a gold alloy were tested. Each specimen was immersed in a simulated body fluid (SBF whose pH value was controlled (2.0, 3.0, 5.0, 7.4, and 9.0 using either hydrochloric or lactic acid. The parameters investigated were the following: duration of immersion, pH of the SBF, contact with a dissimilar metal, and mechanical stimulus. The amounts of Ti ions eluted were measured using a polarized Zeeman atomic absorption spectrophotometer. RESULTS: Eluted Ti ions were detected after 24 h (pH of 2.0 and 3.0 and after 48 h (pH of 9.0. However, even after 4 weeks, eluted Ti ions were not detected in SBF solutions with pH values of 5.0 and 7.4. Ti elution was affected by immersion time, pH, acid type, mechanical stimulus, and contact with a dissimilar metal. Elution of Ti ions in a Candida albicans culture medium was observed after 72 h. SIGNIFICANCE: Elution of Ti ions in the SBF was influenced by its pH and by crevice corrosion. The results of this study elucidate the conditions that lead to the elution of Ti ions in humans, which results in implant corrosion and Ti allergy.

  5. Cesium and Strontium Leaching from Melt Simulators Formed by Camouflet Nuclear Explosion

    International Nuclear Information System (INIS)

    Bondarenko, V.N.; Goncharov, A.V.; Mazilov, A.A.; Mazilov, A.V.; Razsukovannyj, B.N.; Sosipatrov, M.V.; Surkov, A.E.; Sukhostavets, V.I.; Tolstolutskij, A.G.

    2005-01-01

    The paper is devoted to manufacturing of glassceramic melt simulators formed by a nuclear explosion with power 0,3 kt, carried out in 1979 in Ukraine at mine in Enakievo of Donetsk region on the depth of 903 m in sandstone thickness. Also this paper shows the investigation of glassceramic melt simulators chemical stability (solubility) by a method of cesium and strontium leaching. Definition of both the samples element composition and cesium and strontium concentration in the solution was carried out with help of nuclear-physical methods of the analysis in output blocks of the electrostatic accelerator 'SOKOL'. The obtained results have allowed to determine the 137 Cs and 90 Sr concentration in mine water washing cavity created by explosion, and to predict radiation consequences in case of flooding mine excavation

  6. Radiological dispersal device outdoor simulation test: Cesium chloride particle characteristics

    International Nuclear Information System (INIS)

    Lee, Sang Don; Snyder, Emily G.; Willis, Robert; Fischer, Robert; Gates-Anderson, Dianne; Sutton, Mark; Viani, Brian; Drake, John; MacKinney, John

    2010-01-01

    Particles were generated from the detonation of simulated radiological dispersal devices (RDDs) using non-radioactive CsCl powder and explosive C4. The physical and chemical properties of the resulting particles were characterized. Two RDD simulation tests were conducted at Lawrence Livermore National Laboratory: one of the simulated RDDs was positioned 1 m above a steel plate and the other was partially buried in soil. Particles were collected with filters at a distance of 150 m from the origin of the RDD device, and particle mass concentrations were monitored to identify the particle plume intensity using real time particle samplers. Particles collected on filters were analyzed via computer-controlled scanning electron microscopy coupled with energy dispersive X-ray spectrometry (CCSEM/EDX) to determine their size distribution, morphology, and chemical constituents. This analysis showed that particles generated by the detonation of explosives can be associated with other materials (e.g., soil) that are in close proximity to the RDD device and that the morphology and chemical makeup of the particles change depending on the interactions of the RDD device with the surrounding materials.

  7. Experiments and simulations for the dynamics of cesium in negative hydrogen ion sources for ITER N-NBI

    Energy Technology Data Exchange (ETDEWEB)

    Gutser, Raphael

    2010-07-21

    The injection of fast neutral particles (NBI) into a fusion plasma is an important method for plasma heating and current drive. A source for negative deuterium ions delivering an 1 MeV beam that is accelerated to a specific energy and neutralized by a gas target is required for the ITER-NBI. Cesium seeding is required to extract high negative ion current densities from these sources. The optimization of the cesium homogeneity and control are major objectives to achieve the source requirements imposed by ITER. Within the scope of this thesis, the Monte Carlo based numerical transport simulation CsFlow3D was developed, which is the first computer model that is capable of simulating the flux and the accumulation of cesium on the surfaces of negative-ion sources. Basic studies that support the code development were performed at a dedicated experiment at the University of Augsburg. Input parameters of the ad- and desorption of cesium at ion source relevant conditions were taken from systematic measurements with a quartz micro balance, while the injection rate of the cesium oven at the ion source was determined by surface ionization detection. This experimental setup was used for further investigations of the work function of cesium-coated samples during plasma exposure. (orig.)

  8. Experiments and simulations for the dynamics of cesium in negative hydrogen ion sources for ITER N-NBI

    International Nuclear Information System (INIS)

    Gutser, Raphael

    2010-01-01

    The injection of fast neutral particles (NBI) into a fusion plasma is an important method for plasma heating and current drive. A source for negative deuterium ions delivering an 1 MeV beam that is accelerated to a specific energy and neutralized by a gas target is required for the ITER-NBI. Cesium seeding is required to extract high negative ion current densities from these sources. The optimization of the cesium homogeneity and control are major objectives to achieve the source requirements imposed by ITER. Within the scope of this thesis, the Monte Carlo based numerical transport simulation CsFlow3D was developed, which is the first computer model that is capable of simulating the flux and the accumulation of cesium on the surfaces of negative-ion sources. Basic studies that support the code development were performed at a dedicated experiment at the University of Augsburg. Input parameters of the ad- and desorption of cesium at ion source relevant conditions were taken from systematic measurements with a quartz micro balance, while the injection rate of the cesium oven at the ion source was determined by surface ionization detection. This experimental setup was used for further investigations of the work function of cesium-coated samples during plasma exposure. (orig.)

  9. Animated molecular dynamics simulations of hydrated Cesium-smectite interlayers

    International Nuclear Information System (INIS)

    Sutton, Rebecca; Sposito, Garrison

    2002-01-01

    Computer animation of center of mass coordinates obtained from 800 ps molecular dynamics simulations of Cs-smectite hydrates (1/3 and 2/3 water monolayers) provided information concerning the structure and dynamics of the interlayer region that could not be obtained through traditional analytical methods. Cs+ could be seen to jump from one attracting location near a layer charge site to the next, and water molecules were observed to migrate from the hydration shell of one ion to that of another. Neighboring ions maintained a partial hydration shell by sharing water molecules, such that a single water molecule hydrated two ions simultaneously for hundreds of picoseconds. The extent of this sharing interaction in the interlayer was determined by the smectite charge distribution, but increased with increasing water content. Water molecules also could be seen to interact directly with the mineral surface, entering its ditrigonal cavities to approach attracting charge sites. The frequency and duration of cavity habitation increased with increasing water content and tetrahedral charge, and was inhibited the more perpendicular was the structural hydroxyl orientation relative to the mineral surface. Competition between Cs+ and water molecules for surface sites was evident. These important cooperative and competitive features of interlayer molecular behavior were uniquely revealed by animation of an otherwise highly complex simulation output

  10. Simulation of elution profiles in liquid chromatography - II: Investigation of injection volume overload under gradient elution conditions applied to second dimension separations in two-dimensional liquid chromatography.

    Science.gov (United States)

    Stoll, Dwight R; Sajulga, Ray W; Voigt, Bryan N; Larson, Eli J; Jeong, Lena N; Rutan, Sarah C

    2017-11-10

    An important research direction in the continued development of two-dimensional liquid chromatography (2D-LC) is to improve the detection sensitivity of the method. This is especially important in applications where injection of large volumes of effluent from the first dimension ( 1 D) column into the second dimension ( 2 D) column leads to severe 2 D peak broadening and peak shape distortion. For example, this is common when coupling two reversed-phase columns and the organic solvent content of the 1 D mobile phase overwhelms the 2 D column with each injection of 1 D effluent, leading to low resolution in the second dimension. In a previous study we validated a simulation approach based on the Craig distribution model and adapted from the work of Czok and Guiochon [1] that enabled accurate simulation of simple isocratic and gradient separations with very small injection volumes, and isocratic separations with mismatched injection and mobile phase solvents [2]. In the present study we have extended this simulation approach to simulate separations relevant to 2D-LC. Specifically, we have focused on simulating 2 D separations where gradient elution conditions are used, there is mismatch between the sample solvent and the starting point in the gradient elution program, injection volumes approach or even exceed the dead volume of the 2 D column, and the extent of sample loop filling is varied. To validate this simulation we have compared results from simulations and experiments for 101 different conditions, including variation in injection volume (0.4-80μL), loop filling level (25-100%), and degree of mismatch between sample organic solvent and the starting point in the gradient elution program (-20 to +20% ACN). We find that that the simulation is accurate enough (median errors in retention time and peak width of -1.0 and -4.9%, without corrections for extra-column dispersion) to be useful in guiding optimization of 2D-LC separations. However, this requires that real

  11. Sorption of cesium on Latvian clays

    International Nuclear Information System (INIS)

    Viss, R.; Drille, M.

    2004-01-01

    Cesium is like potassium - good solubility and mobile in a ground, easily assimilate in organism expressly brawn woof. It is a problem if pollutant is a radioactive 137 Cs. We made experiments to sorption a 2M CsF solution on some Latvian clays which mainly contain hydro micas (cesium content after good elute of clays are in table). We establish, that clay treated with 25 % sulfuric acid adsorb cesium two times more that waste clay. Hereto unstuck elute Cs from clays. (author)

  12. 2012 Annual Report: Simulate and Evaluate the Cesium Transport and Accumulation in Fukushima-Area Rivers by the TODAM Code

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo; Yokuda, Satoru T.

    2013-03-28

    Pacific Northwest National Laboratory initiated the application of the time-varying, one-dimensional sediment-contaminant transport code, TODAM (Time-dependent, One-dimensional, Degradation, And Migration) to simulate the cesium migration and accumulation in the Ukedo River in Fukushima. This report describes the preliminary TODAM simulation results of the Ukedo River model from the location below the Ougaki Dam to the river mouth at the Pacific Ocean. The major findings of the 100-hour TODAM simulation of the preliminary Ukedo River modeling are summarized as follows:

  13. Simulation software of radioactive decay, β and γ disintegration of cesium 137

    International Nuclear Information System (INIS)

    Laugier, J. M.

    2009-01-01

    We present a software dedicated to radioactivity studies, in particular to radioactive decays. The software has been developed to model the C.R.A.B. (Alpha Beta radioactivity counter), a device constructed in the seventies for use as an educational support for radioactive studies in french schools. The evolution of safety rules prevents nowadays the use of such educational devices in schools. At the origin, the software was developed to train students before a tutorial session using a real radioactive source of Cesium 237 and now the software substitutes entirely the experiments. Indeed, the simulation reassures parents and students who are always afraid of radioactivity. Various studies are proposed: study of the exponential nuclear radioactive decay on a network of radioactive nuclei and roll of dices, Poisson and Gauss distributions, influence of the source-detector distance, radiation absorption by aluminum or by lead. This software is currently used either in the last year of high school or at the University for students in their first year. (author)

  14. Radiochemical determination of cesium-137 in seawater

    International Nuclear Information System (INIS)

    Cunha, I.I.L.; Munita, C.S.; Paiva, R.P.

    1990-01-01

    Seawater samples were collected from the Atlantic Ocean, in the vicinity of Ubatuba (Sao Paulo State - Brazil), acidified to pH 1 and stored in polyethylene containers. Cesium was precipitated with ammonium phospho molybdate (AMP), synthesized in our laboratory. The elements potassium and rubidium present in the seawater are also coprecipitated by AMP and adequate decontamination of the cesium is made by preparing a column by mixing Cs-137 AMP precipitate and asbestos. The interfering elements were eluted with 1.0 M ammonium nitrate solution whereas cesium was eluted with 1.0 M sodium hydroxide solution. Cesium was reprecipitated by acidifying the solution with concentrated hydrochloric acid. The overall chemical yield of cesium was of 75%. (author)

  15. Measurement of cesium and mercury emissions from the vitrification of simulated high level radioactive waste

    International Nuclear Information System (INIS)

    Zamecnik, J.R.

    1992-01-01

    In the Defense Waste Processing Facility at the Savannah River Site, it is desired to measure non-radioactive cesium in the offgas system from the glass melter. From a pilot scale melter system, offgas particulate samples were taken on filter paper media and analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The ICP-MS method proved to be sufficiently sensitive to measure cesium quantities as low as 0.135 μg, with the sensitivity being limited by the background cesium present in the filter paper. This sensitivity allowed determination of cesium decontamination factors for four of the five major components of the offgas system. In addition, total particulate measurements were also made. Measurements of mercury decontamination factors were made on the same equipment; the results indicate that most of the mercury in the offgas system probably exists as elemental mercury and HgCl 2 , with some HgO and Hg 2 Cl 2 . The decontamination factors determined for cesium, total particulate, and mercury all compared favorably with the design values

  16. Water hyacinth for phytoremediation of radioactive waste simulate contaminated with cesium and cobalt radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, H.M., E-mail: hosamsaleh70@yahoo.com [Radioisotope Department, Nuclear Research Center, Atomic Energy Authority, Dokki 12311, Giza (Egypt)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Phytoremediation of radioactive wastes containing {sup 137}Cs and {sup 60}Co radionuclides. Black-Right-Pointing-Pointer Using water hyacinth for radioactive waste treatment. Black-Right-Pointing-Pointer Bioaccumulation of radionuclides from radioactive waste streams. Black-Right-Pointing-Pointer Factors affecting bioaccumulation of {sup 137}Cs and {sup 60}Co using floating plants. - Abstract: Phytoremediation is based on the capability of plants to remove hazardous contaminants present in the environment. This study aimed to demonstrate some factors controlling the phytoremediation efficiency of live floating plant, water hyacinth (Eichhornia crassipes), towards the effluents contaminated with {sup 137}Cs and/or {sup 60}Co. Cesium has unknown vital biological role for plant while cobalt is one of the essential trace elements required for plant. The main idea of this work i.e. using undesirable species, water hyacinth, in purification of radiocontaminated aqueous solutions has been receiving much attention. The controlling factors such as radioactivity concentration, pH values, the amount of biomass and the light were studied. The uptake rate of radiocesium from the simulated waste solution is inversely proportional to the initial activity content and directly proportional to the increase in mass of plant and sunlight exposure. A spiked solution of pH Almost-Equal-To 4.9 was found to be the suitable medium for the treatment process. The uptake efficiency of {sup 137}Cs present with {sup 60}Co in mixed solution was higher than if it was present separately. On the contrary, uptake of {sup 60}Co is affected negatively by the presence of {sup 137}Cs in their mixed solution. Sunlight is the most required factor for the plant vitality and radiation resistance. The results of the present study indicated that water hyacinth may be a potential candidate plant of high concentration ratios (CR) for phytoremediation of radionuclides

  17. Water hyacinth for phytoremediation of radioactive waste simulate contaminated with cesium and cobalt radionuclides

    International Nuclear Information System (INIS)

    Saleh, H.M.

    2012-01-01

    Highlights: ► Phytoremediation of radioactive wastes containing 137 Cs and 60 Co radionuclides. ► Using water hyacinth for radioactive waste treatment. ► Bioaccumulation of radionuclides from radioactive waste streams. ► Factors affecting bioaccumulation of 137 Cs and 60 Co using floating plants. - Abstract: Phytoremediation is based on the capability of plants to remove hazardous contaminants present in the environment. This study aimed to demonstrate some factors controlling the phytoremediation efficiency of live floating plant, water hyacinth (Eichhornia crassipes), towards the effluents contaminated with 137 Cs and/or 60 Co. Cesium has unknown vital biological role for plant while cobalt is one of the essential trace elements required for plant. The main idea of this work i.e. using undesirable species, water hyacinth, in purification of radiocontaminated aqueous solutions has been receiving much attention. The controlling factors such as radioactivity concentration, pH values, the amount of biomass and the light were studied. The uptake rate of radiocesium from the simulated waste solution is inversely proportional to the initial activity content and directly proportional to the increase in mass of plant and sunlight exposure. A spiked solution of pH ≈ 4.9 was found to be the suitable medium for the treatment process. The uptake efficiency of 137 Cs present with 60 Co in mixed solution was higher than if it was present separately. On the contrary, uptake of 60 Co is affected negatively by the presence of 137 Cs in their mixed solution. Sunlight is the most required factor for the plant vitality and radiation resistance. The results of the present study indicated that water hyacinth may be a potential candidate plant of high concentration ratios (CR) for phytoremediation of radionuclides such as 137 Cs and 60 Co.

  18. Preliminary results from uranium/americium affinity studies under experimental conditions for cesium removal from NPP ''Kozloduy'' simulated wastes solutions

    International Nuclear Information System (INIS)

    Nikiforova, A.; Kinova, L.; Peneva, C.; Taskaeva, I.; Petrova, P.

    2005-01-01

    We use the approach described by Westinghouse Savannah River Company using ammonium molybdophosphate (AMP) to remove elevated concentrations of radioactive cesium to facilitate handling waste samples from NPP K ozloduy . Preliminary series of tests were carried out to determine the exact conditions for sufficient cesium removal from five simulated waste solutions with concentrations of compounds, whose complexing power complicates any subsequent processing. Simulated wastes solutions contain high concentrations of nitrates, borates, H 2 C 2 O 4 , ethylenediaminetetraacetate (EDTA) and Citric acid, according to the composition of the real waste from the NPP. On this basis a laboratory treatment protocol was created. This experiment is a preparation for the analysis of real waste samples. In this sense the results are preliminary. Unwanted removal of non-cesium radioactive species from simulated waste solutions was studied with gamma spectrometry with the aim to find a compromise between on the one hand the AMP effectiveness and on the other hand unwanted affinity to AMP of Uranium and Americium. Success for the treatment protocol is defined by proving minimal uptake of U and Am, while at the same time demonstrating good removal effectiveness through the use of AMP. Uptake of U and Am were determined as influenced by oxidizing agents at nitric acid concentrations, proposed by Savannah River National laboratory. It was found that AMP does not significantly remove U and Am when concentration of oxidizing agents is more than 0.1M for simulated waste solutions and for contact times inherent in laboratory treatment protocol. Uranium and Americium affinity under experimental conditions for cesium removal were evaluated from gamma spectrometric data. Results are given for the model experiment and an approach for the real waste analysis is chosen. Under our experimental conditions simulated wastes solutions showed minimal affinity to AMP when U and Am are most probably in

  19. The Effect of a Simulated Macropore on the Colloid-Facilitated Transport of Cesium and Strontium: Experiment and Model Results

    Science.gov (United States)

    Dittrich, T. M.; Ryan, J. N.; Saiers, J. E.

    2011-12-01

    The sorption of contaminants to mobile colloids has been shown to increase the transport of the contaminants in a process known as colloid-facilitated transport. Many laboratory experiments and computer model simulations have shown that enhanced transport can occur when a contaminant strongly associates with mobile colloids and release kinetics are slow relative to the rate of flow. Knowing when colloid-facilitated transport will affect field-scale situations and risk assessment decisions has been difficult. The three parts of our research were (1) conduct a set of isotherms and breakthrough curves for a well-characterized system (illite colloids, homogeneous quartz sand, saturated and unsaturated conditions), (2) conduct breakthrough experiments with the addition of a central macropore and, (3) model the results to identify and quantify the effects of desorption kinetics and unsaturated conditions on colloid-facilitated transport with a macropore. Breakthrough experiments used a 12.7 cm diameter and 33.5 cm long column packed with cleaned and sieved quartz sand. The homogeneous experiments used sand with a median grain size of 0.325 mm. For macropore experiments, a 2 cm diameter tube of 1.6 mm sand (about 5× the size of the matrix sand) was packed in the center of the column. A rainfall simulator was suspended over the column and a relative saturation of 1.0, 0.80, or 0.33 was established. Three moisture sensors and three tensiometers monitored the flow conditions. Effluent was collected with a peristaltic pump and a fraction collector and measured for total and dissolved ions, pH, and colloid concentration. Cesium and strontium were used as model contaminants because they are common contaminants found on Department of Energy sites in the United States and because they have contrasting sorption kinetics with illite. A previously developed model for saturated colloid-facilitated transport of cesium and strontium was extended to accommodate unsaturated conditions

  20. Simulation of Sediment and Cesium Transport in the Ukedo River and the Ogi Dam Reservoir during a Rainfall Event using the TODAM Code

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo; Yokuda, Satoru T.; Kurikami, Hiroshi

    2014-03-28

    The accident at the Fukushima Daiichi Nuclear Power Plant in March 2011 caused widespread environmental contamination. Although decontamination activities have been performed in residential areas of the Fukushima area, decontamination of forests, rivers, and reservoirs is still controversial because of the economical, ecological, and technical difficulties. Thus, an evaluation of contaminant transport in such an environment is important for safety assessment and for implementation of possible countermeasures to reduce radiation exposure to the public. The investigation revealed that heavy rainfall events play a significant role in transporting radioactive cesium deposited on the land surface, via soil erosion and sediment transport in rivers. Therefore, we simulated the sediment and cesium transport in the Ukedo River and its tributaries in Fukushima Prefecture, including the Ogaki Dam Reservoir, and the Ogi Dam Reservoir of the Oginosawa River in Fukushima Prefecture during and after a heavy rainfall event by using the TODAM (Time-dependent, One-dimensional Degradation And Migration) code. The main outcomes are the following: • Suspended sand is mostly deposited on the river bottom. Suspended silt and clay, on the other hand, are hardly deposited in the Ukedo River and its tributaries except in the Ogaki Dam Reservoir in the Ukedo River even in low river discharge conditions. • Cesium migrates mainly during high river discharge periods during heavy rainfall events. Silt and clay play more important roles in cesium transport to the sea than sand does. • The simulation results explain variations in the field data on cesium distributions in the river. Additional field data currently being collected and further modeling with these data may shed more light on the cesium distribution variations. • Effects of 40-hour heavy rainfall events on clay and cesium transport continue for more than a month. This is because these reservoirs slow down the storm-induced high

  1. Cesium absorption from acidic solutions using ammonium molybdophosphate on a polyacrylonitrile support (AMP-PAN)

    International Nuclear Information System (INIS)

    Miller, C.J.; Olson, A.L.; Johnson, C.K.

    1995-01-01

    Recent efforts at the Idaho Chemical Processing Plant (ICPP) have included evaluation of cesium removal technologies as applied to ICPP acidic radioactive waste streams. Ammonium molybdophosphate (AMP) immobilized on a polyacrylonitrile support (AMP-PAN) has been studied as an ion exchange agent for cesium removal from acidic waste solutions. Capacities, distribution coefficients, elutability, and kinetics of cesium-extraction have been evaluated. Exchange breakthrough curves using small columns have been determined from 1M HNO 3 and simulated waste solutions. The theoretical capacity of AMP is 213 g Cs/kg AMP. The average experimental capacity in batch contacts with various acidic solutions was 150 g Cs/kg AMP. The measured cesium distribution coefficients from actual waste solutions were 3287 mL/g for dissolved zirconia calcines, and 2679 mL/g for sodium-bearing waste. The cesium in the dissolved alumina calcines was analyzed for; however, the concentration was below analytical detectable limits resulting in inconclusive results. The reaction kinetics are very rapid (2-10 minutes). Cesium absorption appears to be independent of acid concentration over the range tested (0.1 M to 5 M HNO 3 )

  2. Bench-scale treatability studies for simulated incinerator scrubber blowdown containing radioactive cesium and strontium

    International Nuclear Information System (INIS)

    Coroneos, A.C.; Taylor, P.A.; Arnold, W.D. Jr.; Bostick, D.A.; Perona, J.J.

    1994-12-01

    The purpose of this report is to document the results of bench-scale testing completed to remove 137 Cs and 90 Sr from the Oak Ridge K-25 Site Toxic Substances Control Act (TSCA) Incinerator blowdown at the K-25 Site Central Neutralization Facility, a wastewater treatment facility designed to remove heavy metals and uranium from various wastewaters. The report presents results of bench-scale testing using chabazite and clinoptilolite zeolites to remove cesium and strontium; using potassium cobalt ferrocyanide (KCCF) to remove cesium; and using strontium chloride coprecipitation, sodium phosphate coprecipitation, and calcium sulfate coprecipitation to remove strontium. Low-range, average-range, and high-range concentration blowdown surrogates were used to complete the bench-scale testing

  3. Performance evaluation of 24 ion exchange materials for removing cesium and strontium from actual and simulated N-Reactor storage basin water

    Energy Technology Data Exchange (ETDEWEB)

    Brown, G.N.; Carson, K.J.; DesChane, J.R.; Elovich, R.J.

    1997-09-01

    This report describes the evaluation of 24 organic and inorganic ion exchange materials for removing cesium and strontium from actual and simulated waters from the 100 Area 105 N-Reactor fuel storage basin. The data described in this report can be applied for developing and evaluating ion exchange pre-treatment process flowsheets. Cesium and strontium batch distribution ratios (K{sub d}`s), decontamination factors (DF), and material loadings (mmol g{sup -1}) are compared as a function of ion exchange material and initial cesium concentration. The actual and simulated N-Basin waters contain relatively low levels of aluminum, barium, calcium, potassium, and magnesium (ranging from 8.33E-04 to 6.40E-05 M), with slightly higher levels of boron (6.63E-03 M) and sodium (1.62E-03 M). The {sup 137}Cs level is 1.74E-06 Ci L-{sup 1} which corresponds to approximately 4.87E-10 M Cs. The initial Na/Cs ratio was 3.33E+06. The concentration of total strontium is 4.45E-06 M, while the {sup 90}Sr radioactive component was measured to be 6.13E-06 Ci L{sup -1}. Simulant tests were conducted by contacting 0.067 g or each ion exchange material with approximately 100 mL of either the actual or simulated N-Basin water. The simulants contained variable initial cesium concentrations ranging from 1.00E-04 to 2.57E- 10 M Cs while all other components were held constant. For all materials, the average cesium K{sub d} was independent of cesium concentration below approximately 1.0E-06 M. Above this level, the average cesium K{sub d} values decreased significantly. Cesium K{sub d} values exceeding 1.0E+07 mL g{sup -1} were measured in the simulated N-Basin water. However, when measured in the actual N-Basin water the values were several orders of magnitude lower, with a maximum of 1.24E+05 mL g{sup -1} observed.

  4. Recovery of cesium ion from the aqueous solution by the electric occlusion using a porous aluminum electrode

    International Nuclear Information System (INIS)

    Ihara, Tatsuhiko; Tanaka, Naomichi; Yamanishi, Hirokuni; Noma, Hiroshi

    2015-01-01

    Using stable isotopic cesium with the concentration that simulated the pollution level around the Fukushima Daiichi Nuclear Power Station, the authors examined the occlusion capacity of a porous aluminum electrode based on a beaker-level experiment. A tested aluminum sample was made of metallic aluminum particles having an average particle diameter of 0.2 mm and a porosity of 50%. A cesium standard solution had 4 ppm of cesium chloride concentration, equivalent to 12.86 GBq/L when converted to radioactive cesium. A platinum anode and a porous aluminum cathode were used in the experiment. With occlusion time and applied voltage increased, cesium concentration decreased, reaching the concentration of trace with the applied voltage of 100 V for 90 min for occlusion, and nearly 0 ppm after 120 min. The occlusion capacity of the porous aluminum electrode was unabated even after 20 times of repetitions, exhibiting a high durability. The elution amount of the occluded cesium was 2.1% through washing, and 0.16% after reverse voltage added, which proved the effectiveness of the porous aluminum electrode. A similar effect was confirmed even in strontium. (A.O.)

  5. Preliminary Three-Dimensional Simulation of Sediment and Cesium Transport in the Ogi Dam Reservoir using FLESCOT – Task 6, Subtask 2

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo; Kurikami, Hiroshi; Yokuda, Satoru T.

    2014-03-28

    After the accident at the Fukushima Daiichi Nuclear Power Plant in March 2011, the Japan Atomic Energy Agency and the Pacific Northwest National Laboratory initiated a collaborative project on environmental restoration. In October 2013, the collaborative team started a task of three-dimensional modeling of sediment and cesium transport in the Fukushima environment using the FLESCOT (Flow, Energy, Salinity, Sediment Contaminant Transport) code. As the first trial, we applied it to the Ogi Dam Reservoir that is one of the reservoirs in the Japan Atomic Energy Agency’s (JAEA’s) investigation project. Three simulation cases under the following different temperature conditions were studied: • incoming rivers and the Ogi Dam Reservoir have the same water temperature • incoming rivers have lower water temperature than that of the reservoir • incoming rivers have higher water temperature than that of the reservoir. The preliminary simulations suggest that seasonal temperature changes influence the sediment and cesium transport. The preliminary results showed the following: • Suspended sand, and cesium adsorbed by sand, coming into the reservoirs from upstream rivers is deposited near the reservoir entrance. • Suspended silt, and cesium adsorbed by silt, is deposited farther in the reservoir. • Suspended clay, and cesium adsorbed by clay, travels the farthest into the reservoir. With sufficient time, the dissolved cesium reaches the downstream end of the reservoir. This preliminary modeling also suggests the possibility of a suitable dam operation to control the cesium migration farther downstream from the dam. JAEA has been sampling in the Ogi Dam Reservoir, but these data were not yet available for the current model calibration and validation for this reservoir. Nonetheless these preliminary FLESCOT modeling results were qualitatively valid and confirmed the applicability of the FLESCOT code to the Ogi Dam Reservoir, and in general to other reservoirs in

  6. Electrically switched cesium ion exchange

    International Nuclear Information System (INIS)

    Lilga, M.A.; Orth, R.J.; Sukamto, J.P.H.; Schwartz, D.T.; Haight, S.M.; Genders, J.D.

    1997-04-01

    Electrically Switched Ion Exchange (ESIX) is a separation technology being developed as an alternative to conventional ion exchange for removing radionuclides from high-level waste. The ESIX technology, which combines ion exchange and electrochemistry, is geared toward producing electroactive films that are highly selective, regenerable, and long lasting. During the process, ion uptake and elution are controlled directly by modulating the potential of an ion exchange film that has been electrochemically deposited onto a high surface area electrode. This method adds little sodium to the waste stream and minimizes the secondary wastes associated with traditional ion exchange techniques. Development of the ESIX process is well underway for cesium removal using ferrocyanides as the electroactive films. Films having selectivity for perrhenate (a pertechnetate surrogate) over nitrate also have been deposited and tested. A case study for the KE Basin on the Hanford Site was conducted based on the results of the development testing. Engineering design baseline parameters for film deposition, film regeneration, cesium loading, and cesium elution were used for developing a conceptual system. Order of magnitude cost estimates were developed to compare with conventional ion exchange. This case study demonstrated that KE Basin wastewater could be processed continuously with minimal secondary waste and reduced associated disposal costs, as well as lower capital and labor expenditures

  7. Selective capture of cesium and thallium from natural waters and simulated wastes with copper ferrocyanide functionalized mesoporous silica

    International Nuclear Information System (INIS)

    Sangvanich, Thanapon; Sukwarotwat, Vichaya; Wiacek, Robert J.; Grudzien, Rafal M.; Fryxell, Glen E.; Addleman, R. Shane; Timchalk, Charles; Yantasee, Wassana

    2010-01-01

    Copper(II) ferrocyanide on mesoporous silica (FC-Cu-EDA-SAMMS TM ) has been evaluated against iron(III) hexacyanoferrate(II) (insoluble Prussian Blue) for removing cesium (Cs + ) and thallium (Tl + ) from natural waters and simulated acidic and alkaline wastes. From pH 0.1-7.3, FC-Cu-EDA-SAMMS had greater affinities for Cs and Tl and was less affected by the solution pH, competing cations, and matrices. SAMMS also outperformed Prussian Blue in terms of adsorption capacities (e.g., 21.7 versus 2.6 mg Cs/g in acidic waste stimulant (pH 1.1), 28.3 versus 5.8 mg Tl/g in seawater), and rate (e.g., over 95 wt% of Cs was removed from seawater after 2 min with SAMMS, while only 75 wt% was removed with Prussian Blue). SAMMS also had higher stability (e.g., 2.5-13-fold less Fe dissolved from 2 to 24 h of contact time). In addition to environmental applications, SAMMS has great potential to be used as orally administered drug for limiting the absorption of radioactive Cs and toxic Tl in gastrointestinal tract.

  8. Selective Capture of Cesium and Thallium from Natural Waters and Simulated Wastes with Copper Ferrocyanide Functionalized Mesoporous Silica

    Science.gov (United States)

    Sangvanich, Thanapon; Sukwarotwat, Vichaya; Wiacek, Robert J.; Grudzien, Rafal M.; Fryxell, Glen E.; Addleman, R. Shane; Timchalk, Charles; Yantasee, Wassana

    2010-01-01

    Copper(II) ferrocyanide on mesoporous silica (FC-Cu-EDA-SAMMS™) has been evaluated against iron(III) hexacyanoferrate(II) (insoluble Prussian Blue) for removing cesium (Cs+) and thallium (Tl+) from natural waters and simulated acidic and alkaline wastes. From pH 0.1 – 7.3, FC-Cu-EDA-SAMMS had greater affinities for Cs and Tl and was less affected by the solution pH, competing cations, and matrices. SAMMS also outperformed Prussian Blue in terms of adsorption capacities (e.g., 21.7 versus 2.6 mg Cs/g in acidic waste stimulant (pH 1.1), 28.3 versus 5.8 mg Tl/g in seawater), and rate (e.g., over 95 wt% of Cs was removed from seawater after 2 min with SAMMS, while only 75 wt% was removed with Prussian Blue). SAMMS also had higher stability (e.g., 2.5 to 13-fold less Fe dissolved from 2 to 24 hr of contact time). In addition to environmental applications, SAMMS has great potential to be used as orally administered drug for limiting the absorption of radioactive Cs and toxic Tl in gastrointestinal tract. PMID:20594644

  9. Cesium selenatoindiates

    International Nuclear Information System (INIS)

    Kadoshnikova, N.V.; Dejchman, Eh.N.; Tananaev, I.V.

    1977-01-01

    The system Cs 2 SeO 4 -In 2 (SeO 4 ) 3 -H 2 O has been studied by the isothermal solubility method at 20 deg C. Crystal optical analysis of CsIn(SeO 4 ) 2 x2H 2 O has been conducted. CsIn(SeO 4 ) 2 x12H 2 O has been synthesized at 0-+5 deg C. The individual structure of dihydrate and non-aqueous cesium selenateindiates has been confirmed by X-ray phase analysis

  10. Process for recovering cesium from cesium alum

    International Nuclear Information System (INIS)

    Mein, P.G.

    1984-01-01

    Cesium is recovered from cesium alum, CsAl(SO 4 ) 2 , by a two-reaction sequence in which the cesium alum is first dissolved in an aqueous hydroxide solution to form cesium alum hydroxide, CsAl(OH) 3 , and potassium sulfate, K 2 SO 4 . Part of the K 2 SO 4 precipitates and is separated from the supernatant solution. In the second reaction, a water-soluble permanganate, such as potassium permanganate, KMnO 4 , is added to the supernatant. This reaction forms a precipitate of cesium permanganate, CsMnO 4 . This precipitate may be separated from the residual solution to obtain cesium permanganate of high purity, which can be sold as a product or converted into other cesium compounds

  11. Cesium-137

    International Nuclear Information System (INIS)

    Ammerich, Marc; Frot, Patricia; Gambini, Denis-Jean; Gauron, Christine; Moureaux, Patrick; Herbelet, Gilbert; Lahaye, Thierry; Pihet, Pascal; Rannou, Alain

    2014-06-01

    This sheet belongs to a collection which relates to the use of radionuclides essentially in unsealed sources. Its goal is to gather on a single document the most relevant information as well as the best prevention practices to be implemented. These sheets are made for the persons in charge of radiation protection: users, radioprotection-skill persons, labor physicians. Each sheet treats of: 1 - the radio-physical and biological properties; 2 - the main uses; 3 - the dosimetric parameters; 4 - the measurement; 5 - the protection means; 6 - the areas delimitation and monitoring; 7 - the personnel classification, training and monitoring; 8 - the effluents and wastes; 9 - the authorization and declaration administrative procedures; 10 - the transport; and 11 - the right conduct to adopt in case of incident or accident. This sheet deals specifically with Cesium-137

  12. Management of cesium loaded AMP- Part I preparation of 137Cesium concentrate and cementation of secondary wastes

    International Nuclear Information System (INIS)

    Singh, I.J.; Sathi Sasidharan, N.; Yalmali, Vrunda S.; Deshingkar, D.S.; Wattal, P.K.

    2005-11-01

    Separation of 137 cesium from High Level Waste can be achieved by use of composite-AMP, an engineered form of Ammonium Molybdo-Phosphate(AMP). Direct vitrification of cesium loaded composite AMP in borosilicate glass matrix leads to separation of water soluble molybdate phase. A proposed process describes two different routes of selective separation of molybdates and phosphate to obtain solutions of cesium concentrates. Elution of 137 Cesium from composite-AMP by decomposing it under flow conditions using saturated barium hydroxide was investigated. This method leaves molybdate and phosphate embedded in the column but only 70% of total cesium loaded on column could be eluted. Alternatively composite-AMP was dissolved in sodium hydroxide and precipitation of barium molybdate-phosphate from the resultant solution, using barium nitrate was investigated by batch methods. The precipitation technique gave over 99.9% of 137 Cesium activity in solutions, free of molybdates and phosphates, which is ideally suited for immobilization in borosilicate glass matrix. Detailed studies were carried out to immobilize secondary waste of 137 Cesium contaminated barium molybdate-phosphate precipitates in the slag cement matrix using vermiculite and bentonite as admixtures. The cumulative fraction of 137 Cs leached from the cement matrix blocks was 0.05 in 140 days while the 137 Cs leach rate was 0.001 gm/cm 2 /d. (author)

  13. Effects of β-, γ-radiolysis on cesium iodide solutions in contact with simulated silver metal aerosol

    International Nuclear Information System (INIS)

    Furrer, M.; Gloor, T.

    1986-01-01

    While silver-free, air saturated cesium iodide solutions (1 mMole CsI/l, pH 7) are rather stable even in a strong radiation field (Co-60; 0.5 Mrad/h; 30 0 C), the addition of silver metal as 2 μ-particles produces significant changes. Even without irradiation and in total darkness, more than half of the cesium iodide is converted to silver iodide within 10 hours at room temperature. The described β-, γ-field accelerates silver iodide formation by a factor of roughly three. In all these experiments, a steady state fraction of elemental iodine of typically 0.4% with 0.1% as an absolute minimum is encountered. This steady state concentration of a volatile iodine species so far lacks a theoretical explanation. (author)

  14. Cesium Eluate Analytical Data Evaluation

    International Nuclear Information System (INIS)

    Pierce, R.A.

    2003-01-01

    Bechtel National Inc. (BNI) is using IBC Company's SuperLigand ion exchange resins to separate Cs and Tc from low-activity waste (LAW) solutions (IBC-1996). Cesium is removed using the SuperLig(R) 644 resin. The resin is then eluted after each use cycle with 0.5M nitric acid solution. BNI is planning to evaporate the Cs eluate solution to reduce the storage volume and recover eluate for re-use. The primary issue associated with evaporation is end point, or salt matrix solubility. To preclude formation of solids during the storage of evaporator products, an additional criteria has been set that limits the concentration of the evaporator bottoms to 80 percent of saturation at 25 degrees C. As a result, an understanding of the effects of constituent species on the bulk solubility must be developed prior to effective evaporator operations

  15. Laboratory-Scale Column Testing Using IONSIV IE-911 for Removing Cesium from Acidic Tank Waste Simulant. 2: Determination of Cesium Exchange Capacity and Effective Mass Transfer Coefficient from a 500-cm3 Column Experiment

    International Nuclear Information System (INIS)

    T.J. Tranter; R.D. Tillotson; T.A. Todd

    2005-01-01

    A semi-scale column test was performed using a commercial form of crystalline silicotitanate (CST) for removing radio-cesium from a surrogate acidic tank solution, which represents liquid waste stored at the Idaho National Engineering and Environmental Laboratory (INEEL). The engineered form of CST ion exchanger, known as IONSIVtmIE-911 (UOP, Mt. Laurel, NJ, USA), was tested in a 500-cm3 column to obtain a cesium breakthrough curve. The cesium exchange capacity of this column matched that obtained from previous testing with a 15-mc3 column. A numerical algorithm using implicit finite difference approximations was developed to solve the governing mass transport equations for the CST columns. An effective mass transfer coefficient was derived from solving these equations for previously reported 15 cm3 tests. The effective mass transfer coefficient was then used to predict the cesium breakthrough curve for the 500-cm3 column and compared to the experimental data reported in this paper. The calculated breakthrough curve showed excellent agreement with the data from the 500-cm3 column even though the interstitial velocity was a factor of two greater. Thus, this approach should provide a reasonable method for scale up to larger columns for treating actual tank waste

  16. Chromatographie à contre-courant simulé : développements et perspectives From Batch Elution to Simulated Countercurrent Chromatography

    Directory of Open Access Journals (Sweden)

    Hotier G.

    2006-11-01

    are performed by metering pumps while the raffinate withdrawal is done by an upstream pressure-control valve. The four multiposition valves, the four metering pumps, the pressure control valve and various side devices such as online analyzers of the effluents are commanded by a computer. Two examples of separation performed in these pilot plants are shown: paraxylene separation from C8 aromatic feedstock and xylose separation from xylose-arabinose-glucose mixtures. The experiments performed made it possible to determine both static and dynamic parameters of the process. The main conclusion is that a modelization of the plant is necessary not only for process optimization but also to correctly operate these units. We have developed a model that accurately represents the separation of binary mixtures. Generally multicomponent separations are more difficult to represent and in this respect our model predictions are only qualitative ones. A guideline is then given for making choice between conventional elution chromatography and simulated moving bed separation. Some improvements in this process are also discussed. A five-zone simulated moving bed with reinjection of distilled extract provides great increases in extract purity. It is also possible to combine preparative supercritical chromatography with a simulated moving bed in a sixzone scheme in order to continuously separate three effluent streams. Thus great extensions of the field of application of simulated moving bed separations are expected in the coming years.

  17. Colloid-Facilitated Cesium Transport in the Vadose Zone at the Hanford Site

    Science.gov (United States)

    Chen, G.; Flury, M.; Harsh, J. B.

    2002-12-01

    Transport of 137Cs and colloids through a Hanford sediment column under unsaturated conditions was investigated. The movement of cesium and colloids followed the convective-dispersive solute transport equation and the mass transfer processes governing colloid-facilitated cesium transport were colloidal deposition, cesium sorption to the medium, and cesium sorption to colloids. It was found that cesium was strongly adsorbed to Hanford sediments and only colloid-bound cesium could breakthrough. Cesium experienced a greater facilitated transport at higher saturation than at low saturation and the migration of cesium was more a function of the behavior of colloids than of dissolved cesium. A two-region model was used in describing colloid-facilitated cesium migration and the influence of the system saturation was examined by relating to the variation of simulated model parameters. Hanford native colloids, i.e., \\textit{in-situ} colloids from the Hanford site, and modified colloids, i.e., \\textit{in-situ} colloids subject to chemical treatment, were used as model colloids to study facilitated cesium transport in this research. The results of this study will be of help in understanding the response of colloid-facilitated cesium migration to variation of saturation at the Hanford site. Key words: cesium; colloid; facilitated transport; saturation; and Hanford sediment.

  18. Numerical simulation of cesium and strontium migration through sodium bentonite altered by cation exchange with groundwater components

    International Nuclear Information System (INIS)

    Jacobsen, J.S.; Carnahan, C.L.

    1988-10-01

    Numerical simulations have been used to investigate how spatial and temporal changes in the ion exchange properties of bentonite affect the migration of cationic fission products from high-level waste. Simulations in which fission products compete for exchange sites with ions present in groundwater diffusing into the bentonite are compared to simulations in which the exchange properties of bentonite are constant. 12 refs., 3 figs., 2 tabs

  19. Laboratory-Scale Column Testing Using IONSIV IE-911 for Removing Cesium from Acidic Tank Waste Simulant. 1: Cesium Exchange Capacity of a 15-cm3 Column and Dynamic Stability of the Exchange Media

    International Nuclear Information System (INIS)

    T.J. Tranter; R.D. Tillotson; T.A. Todd

    2005-01-01

    Bench-scale column tests were performed using a commercial form of crystalline silicotitanate (CST) for removing radio-cesium from a surrogate acidic tank solution representative of liquid waste stored at the Idaho National Engineering and Environmental Laboratory (INEEL). An engineered form of CST ion exchanger, known as IONSIVtm IE-911 (UOP, Mt Laurel, NJ, USA), was tested in 15 cm3 columns at a flow rate of 5 bed volumes per hour. These experiments showed the ion exchange material to have reasonable selectivity and capacity for removing cesium from the complex chemical matrix of the solution. However, previous testing indicated that partial neutralization of the feed stream was necessary to increase the stability of the ion exchange media. Thus, in these studies, CST degradation was determined as a function of throughput in order to better assess the stability characteristics of the exchanger for potential future waste treatment applications. Results of these tests indicate that the degradation of the CST reaches a maximum very soon after the acidic feed is introduced to the column and then rapidly declines. Total dissolution of bed material did not exceed 3% under the experimental regime used

  20. Year-end report for UST: Cesium extraction testing project DOE/DT&E TTP No. SR1-03-20-01

    Energy Technology Data Exchange (ETDEWEB)

    Bibler, J.P.

    1994-02-01

    This document contains results of a variety of studies on the SRS (Savannah River Site) resorcinol-formaldehyde ion exchange resin with a simulant of the high-level liquid waste found in the Hanford 101-AW tank. Small column studies indicate that flow rates of 2.5 column volumes or less per hour give well-defined breakthrough curves. More rapid flow rates of three to twenty column volumes per hour produce leakage of cesium ion before 50% breakthrough has been reached after processing about 100 column volumes of feed. Upflow elution of the small columns with three concentrations of nitric acid show that about 85% of the cesium, sodium, and potassium ions on the resin can be removed simultaneously with 0.5 M HNO{sub 3}. Radiolysis studies at doses as high as 1E+09 rads have shown that the resin is more stable to radiation in water than in the 101-AW simulant. Radiation doses up to 1 E+08 rads did not alter the performance of the resin for cesium removal. Exposure to radiation or storage did not affect the thermal stability of the resin. Hydrogen gas is produced from radiolysis of resin in 101-AW simulant. Other gases that were measured were N{sub 2}, O{sub 2}, CO{sub 2}, N{sub 2}O, CO, and CH{sub 4}. Densities and kinetic and dynamic viscosities were determined for the 101-AW simulant at six temperatures ranging between 25{degrees}C and 80{degrees}C. Preliminary results indicated that the performance of the resin was only slightly diminished with increase in temperature although elution efficiency appeared to be enhanced.

  1. Decorporation of cesium-137

    International Nuclear Information System (INIS)

    Le Fleche, Ph.; Destombe, C.; Grasseau, A.; Mathieu, J.; Chancerelle, Y.; Mestries, J.C.

    1997-01-01

    Cesium radio-isotopes, especially cesium-137 ( 137 Cs) are among the radionuclides of main importance produced by a fission reaction in reactor or a nuclear weapon explosion. In the environment, 137 Cs is a major contaminant which can cause severe β, γirradiations and contaminations. 137 Cs is distributed widely and relatively uniformly throughout the body with the highest concentration in skeletal muscles. A treatment becomes difficult afterwards. The purposes of this report are Firstly to compare the Prussian blue verses cobalt and potassium ferrocyanide (D.I. blue) efficiency for the 137 Cs decorporation and secondly to assess a chronological treatment with D.I. blue. (author)

  2. Electrically switched cesium ion exchange. FY 1997 annual report

    International Nuclear Information System (INIS)

    Lilga, M.A.; Orth, R.J.; Sukamto, J.P.H.

    1997-09-01

    This paper describes the Electrically Switched Ion Exchange (ESIX) separation technology being developed as an alternative to ion exchange for removing radionuclides from high-level waste. Progress in FY 1997 for specific applications of ESIX is also outlined. The ESIX technology, which combines ion exchange and electrochemistry, is geared toward producing electroactive films that are highly selective, regenerable, and long lasting. During the process, ion uptake and elution can be controlled directly by modulating the potential of an ion exchange film that has been electrochemically deposited onto a high surface area electrode. This method adds little sodium to the waste stream and minimizes the secondary wastes associated with traditional ion exchange techniques. Development of the ESIX process is well underway for cesium removal using ferrocyanides as the electroactive films. Films having selectivity for perrhenate (a pertechnetate surrogate) over nitrate also have been deposited and tested. Based on the ferrocyanide film capacity, stability, rate of uptake, and selectivity shown during performance testing, it appears possible to retain a consistent rate of removal and elute cesium into the same elution solution over several load/unload cycles. In batch experiments, metal hexacyanoferrate films showed high selectivities for cesium in concentrated sodium solutions. Cesium uptake was unaffected by Na/Cs molar ratios of up to 2 x 10 4 , and reached equilibrium within 18 hours. During engineering design tests using 60 pores per inch, high surface area nickel electrodes, nickel ferrocyanide films displayed continued durability. losing less than 20% of their capacity after 1500 load/unload cycles. Bench-scale flow system studies showed no change in capacity or performance of the ESIX films at a flow rate up to 13 BV/h, the maximum flow rate tested, and breakthrough curves further supported once-through waste processing. 9 refs., 24 figs

  3. Innovative Elution Processes for Recovering Uranium from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Wai, Chien [Univ. of Idaho, Moscow, ID (United States); Tian, Guoxin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Janke, Christopher [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-05-29

    Utilizing amidoxime-based polymer sorbents for extraction of uranium from seawater has attracted considerable interest in recent years. Uranium collected in the sorbent is recovered typically by elution with an acid. One drawback of acid elution is deterioration of the sorbent which is a significant factor that limits the economic competitiveness of the amidoxime-based sorbent systems for sequestering uranium from seawater. Developing innovative elution processes to improve efficiency and to minimize loss of sorbent capacity become essential in order to make this technology economically feasible for large-scale industrial applications. This project has evaluated several elution processes including acid elution, carbonate elution, and supercritical fluid elution for recovering uranium from amidoxime-based polymer sorbents. The elution efficiency, durability and sorbent regeneration for repeated uranium adsorption- desorption cycles in simulated seawater have been studied. Spectroscopic techniques are used to evaluate chemical nature of the sorbent before and after elution. A sodium carbonate-hydrogen peroxide elution process for effective removal of uranium from amidoxime-based sorbent is developed. The cause of this sodium carbonate and hydrogen peroxide synergistic leaching of uranium from amidoxime-based sorbent is attributed to the formation of an extremely stable uranyl peroxo-carbonato complex. The efficiency of uranium elution by the carbonate-hydrogen peroxide method is comparable to that of the hydrochloric acid elution but damage to the sorbent material is much less for the former. The carbonate- hydrogen peroxide elution also does not need any elaborate step to regenerate the sorbent as those required for hydrochloric acid leaching. Several CO2-soluble ligands have been tested for extraction of uranium from the sorbent in supercritical fluid carbon dioxide. A mixture of hexafluoroacetylacetone and tri-n-butylphosphate shows the best result but uranium

  4. Innovative Elution Processes for Recovering Uranium from Seawater

    International Nuclear Information System (INIS)

    Wai, Chien; Tian, Guoxin; Janke, Christopher

    2014-01-01

    Utilizing amidoxime-based polymer sorbents for extraction of uranium from seawater has attracted considerable interest in recent years. Uranium collected in the sorbent is recovered typically by elution with an acid. One drawback of acid elution is deterioration of the sorbent which is a significant factor that limits the economic competitiveness of the amidoxime-based sorbent systems for sequestering uranium from seawater. Developing innovative elution processes to improve efficiency and to minimize loss of sorbent capacity become essential in order to make this technology economically feasible for large-scale industrial applications. This project has evaluated several elution processes including acid elution, carbonate elution, and supercritical fluid elution for recovering uranium from amidoxime-based polymer sorbents. The elution efficiency, durability and sorbent regeneration for repeated uranium adsorption- desorption cycles in simulated seawater have been studied. Spectroscopic techniques are used to evaluate chemical nature of the sorbent before and after elution. A sodium carbonate-hydrogen peroxide elution process for effective removal of uranium from amidoxime-based sorbent is developed. The cause of this sodium carbonate and hydrogen peroxide synergistic leaching of uranium from amidoxime-based sorbent is attributed to the formation of an extremely stable uranyl peroxo-carbonato complex. The efficiency of uranium elution by the carbonate-hydrogen peroxide method is comparable to that of the hydrochloric acid elution but damage to the sorbent material is much less for the former. The carbonate- hydrogen peroxide elution also does not need any elaborate step to regenerate the sorbent as those required for hydrochloric acid leaching. Several CO2-soluble ligands have been tested for extraction of uranium from the sorbent in supercritical fluid carbon dioxide. A mixture of hexafluoroacetylacetone and tri-n-butylphosphate shows the best result but uranium

  5. Cesium powder and pellets inner container decontamination method determination

    International Nuclear Information System (INIS)

    Ferrell, P.C.

    1998-01-01

    The cesium powder and pellets inner container is to be performance tested per the criteria specified in Section 4.0 of HNF-2399, ''Design, Fabrication, and Assembly Criteria for Cesium Powder and Pellet Inner Container.'' The test criteria specifies that the inner container be water tight during decontamination of the exterior surface. Three prototypes will be immersed into a pool of water to simulate a water decontamination process

  6. Development of an ion-exchange process for removing cesium from high-level radioactive liquid wastes

    International Nuclear Information System (INIS)

    Baumgarten, P.K.; Wallace, R.M.; Whitehurst, D.A.; Steed, J.M.

    1979-11-01

    Methods to determine resin characteristics, i.e., cesium equilibria and diffusion rates, were developed. These parameters can now guide resin selection and aid in interpreting column performance. The K/sub D/ cesium ion concentration relation gives evidence of three different types of ion exchange sites. The countercurrent load/elution/regeneration cycle for the removal of cesium by ion exchange repeatedly reached the goal decontamination factor (DF) of 10,000 at throughputs up to 60 column volumes. Resin backwashing appears feasible, but further development of column geometry will be required. The proposed ammonium elutriant is satisfactory. Regeneration end-point can be controlled by electrical conductivity monitoring

  7. Quaternary system of cesium halides

    International Nuclear Information System (INIS)

    Bukhalova, G.A.; Shegurova, G.A.; Yagub'yan, E.S.; Zaporozhets, E.G.

    1977-01-01

    The state diagram of the quaternary system consisting of fluorides, chlorides, bromides, and iodides of cesium has been studied by visual-polythermal, partially X-ray phase and thermographical analyses. The crystallization volume of the quaternary system involves the crystallization volume of cesium fluoride and the crystallization volume of the ternary solid solutions of the rest cesium halides. A quaternary nonvariant point corresponding to melting point 360 deg C appears on the crystallization surface which separates the cesium fluoride volume from the volume of the ternary solid solutions

  8. Modelling the transport of radioactive cesium released from the Fukushima Dai-ichi NPP with sediments through the hydrologic system

    Science.gov (United States)

    Kinouchi, T.; Omata, T.; Wei, L.; Liu, T.; Araya, M.

    2013-12-01

    Due to the accident of the Fukushima Dai-ichi Nuclear Power Plant on March 2011, a huge amount of radionuclides including Cesium-134 and Cesium-137 was deposited over the main island of Japan and the Pacific Ocean, resulting in further transfer and diffusion of Cesium through the atmospheric flow, watershed hydrological processes, and terrestrial ecosystem. Particularly, for the transfer of Cesium-134 and Cesium-137, sediments eroded and transported by the rainfall-runoff processes play an important role as Cesium tends to be strongly adsorbed to soil particles such as clay and silt. In this study, we focus on the transport of sediment and adsorbed Cesium in the watershed-scale hydrologic system to predict the long-term change of distribution of Cesium and its discharge to rivers and ocean. We coupled a physically-based distributed hydrological model with the modules of erosion and transport of sediments and adsorbed Cesium, and applied the coupled model to the Abukuma River watershed, which is located over the area of higher deposition of Cesium. In the model, complex land use and land cover distributions, and the effect of human activities such as irrigation, dam control and urban drainage system are taken into accounts. Simulation was conducted for the period of March 2011 until August 2012, with initial spatial distribution of Cesium-134 and Cesium-137 obtained by the airborne survey. Simulated flow rates and sediment concentrations agreed well with observed, and found that since the accident, two major storms in July and September 2011 transported about 50% of total sediments transported during the simulated periods. Cesium concentration in the sediment was reproduced well except for the difference in the initial periods. This difference is attributable to the uncertainty arisen from the initial distribution of Cesium in the soil and the transfer of Cesium from the forest canopy.

  9. EVALUATION OF PETROLEUM HYDROCARBONS ELUTION FROM SOIL

    Directory of Open Access Journals (Sweden)

    Janina Piekutin

    2015-06-01

    Full Text Available The paper presents studies on oil removal from soil by means of water elution with a help of shaking out the contaminants from the soil. The tests were performed on simulated soil samples contaminated with a mixture of petroleum hydrocarbons. The study consisted in recording the time influence and the number of elution cycles to remove contaminants from the soil. The samples were then subject to the determination of petroleum hydrocarbons, aliphatic hydrocarbons, and BTEX compounds (benzene, toluene, ethylbenzene, xylene. Due to adding various concentrations of petroleum into particular soil samples and applying different shaking times, it was possible to find out the impact of petroleum content and sample shaking duration on the course and possibility of petroleum substances removal by means of elution process.

  10. Preliminary Ion Exchange Modeling for Removal of Cesium from Hanford Waste Using SuperLig 644 Resin

    International Nuclear Information System (INIS)

    Hamm, L.L.

    2000-01-01

    A proposed facility is being designed for the immobilization of Hanford high-level radioactive waste. One unit process in the facility is designed to remove radioactive cesium by ion-exchange from the strongly alkaline aqueous phase. A resin specifically designed with high selectivity of cesium under alkaline conditions is being investigated. The resin also is elutable under more acidic conditions. The proposed design of the facility consists of two sets of two packed columns placed in series (i.e., a lead column followed by a lag (guard) column configuration). During operation, upon reaching a specified cesium concentration criterion at the exit of the lag column, operation is switched to the second set of lead and lag columns. The cesium-loaded lead column is processed (i.e., washed and eluted) and switched to the lag position. the previous lag column is then placed in the lead position (without eluting) and the system is ready for use in the next cycle. For a well designed process, the loading and elution processes result in significant volume reductions in aqueous high-level waste

  11. Improvement of cesium retention in uranium dioxide by additional phases

    International Nuclear Information System (INIS)

    Gamaury Dubois, S.

    1995-01-01

    The objective of this study is to improve the cesium retention in nuclear fuel. A bibliographic survey indicates that cesium is rapidly released from uranium dioxide in an accident condition. At temperatures higher than 1500 deg C or in oxidising conditions, our experiments show the difficulty of maintaining cesium inside simulated fuel. Two ternary systems are potentially interesting for the retention of cesium and to reduce the kinetics of release from the fuel: Cs 2 O-Al 2 O 3 -SiO 2 et Cs 2 O-ZrO 2 -SO 2 . The compounds CsAISi 2 O 6 and Cs 2 ZrSi 6 O 15 were studied from 1200 deg C to 2000 deg C by thermogravimetric analysis. The volumetric diffusion coefficients of cesium in these structures, in solid state as well as in liquid one, were measured. A fuel was sintered with (Al 2 O 3 + SiO 2 ) or (ZrO 2 + SiO 2 ) and the intergranular phase was characterized. In the presence of (Al 2 O 3 + SiO 2 ), the sintering is realized at 1610 deg C in H 2 . It is a liquid phase sintering. On the other end, with (ZrO 2 + SiO 2 ), the sintering is a low temperature one in oxidising atmosphere. Finally, cesium containing simulated fuels were produced with these additives. According to the effective diffusion coefficients that were measured, the additives improved the retention of cesium. We have predicted the improvement that could be hoped for in a nuclear reactor, depending on the dispersion of the intergranular additives, the temperature and the degree of oxidation of the UO 2+x . We wait for a factor of 2 for x=0 and more than 8 for x=0.05, up to 2000 deg C. (author). 148 refs., 122 figs., 34 tabs

  12. Metrology of cesium ion thrusters

    International Nuclear Information System (INIS)

    Benoist, Roger; Labbe, Jean; Le Grives, Emile

    1974-01-01

    The various controls necessary to characterize cesium ion thrusters are presented. The following metrological process was developed by the ONERA: control of the thermal equilibrium and regulation of the temperature of the ionizer and of the cesium supply device, control of the ion current emission characterized both globally and locally, control of the ionization yield by the determination of the number of neutral cesium atoms by means of an appropriate detector and analysis of the structure of the beam by mapping the ionic current density. This characterization is completed by the results of cyclic regime tests runs reproducing the working conditions in satellites [fr

  13. Cesium diffusion in graphite

    International Nuclear Information System (INIS)

    Evans, R.B. III; Davis, W. Jr.; Sutton, A.L. Jr.

    1980-05-01

    Experiments on diffusion of 137 Cs in five types of graphite were performed. The document provides a completion of the report that was started and includes a presentation of all of the diffusion data, previously unpublished. Except for data on mass transfer of 137 Cs in the Hawker-Siddeley graphite, analyses of experimental results were initiated but not completed. The mass transfer process of cesium in HS-1-1 graphite at 600 to 1000 0 C in a helium atmosphere is essentially pure diffusion wherein values of (E/epsilon) and ΔE of the equation D/epsilon = (D/epsilon) 0 exp [-ΔE/RT] are about 4 x 10 -2 cm 2 /s and 30 kcal/mole, respectively

  14. Cesium Ion Exchange Program at the Hanford River Protection Project Waste Treatment Plant

    International Nuclear Information System (INIS)

    CHARLES, NASH

    2004-01-01

    The River Protection Project - Hanford Tank Waste Treatment and Immobilization Plant will use cesium ion exchange to remove 137Cs from Low Activity Waste down to 0.3 Ci/m3 in the Immobilized LAW, ILAW product. The project baseline for cesium ion exchange is the elutable SuperLig, R, 644, SL-644, resin registered trademark of IBC Advanced Technologies, Inc., American Fork, UT or the Department of Energy approved equivalent. SL-644 is solely available through IBC Advanced Technologies. To provide an alternative to this sole-source resin supply, the RPP--WTP initiated a three-stage process for selection and qualification of an alternative ion exchange resin for cesium removal in the RPPWTP. It was recommended that resorcinol formaldehyde RF be pursued as a potential alternative to SL-644

  15. Strontium-90 and cesium-137 in freshwater (from Sept. 1983 to Dec. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Fresh water, 100 l each, was collected, and to which the carriers of strontium and cesium were added immediately after the sampling. The sample was vigorously stirred and filtered, and passed through a cation exchange column. Strontium and cesium were eluted with hydrochloric acid from the cation exchange column. The eluate was used for radiochemical analysis. The chemical separation of strontium-90 and cesium-137 was carried out, and the chemical yields were determined. The precipitates were counted for the activity using low background beta counters normally for 60 min. The net sample counting rate was corrected for the counter efficiency, recovery, self-absorption and decay, to obtain the radioactivity per sample aliquot, and the concentrations of these nuclides in the original samples were calculated. The data at six sampling locations in Japan from September to December, 1983, on fresh water are reported. (Kako, I.)

  16. 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

  17. Selective removal of cesium ions from wastewater using copper hexacyanoferrate nanofilms in an electrochemical system

    International Nuclear Information System (INIS)

    Chen, Rongzhi; Tanaka, Hisashi; Kawamoto, Tohru; Asai, Miyuki; Fukushima, Chikako; Na, Haitao; Kurihara, Masato; Watanabe, Masayuki; Arisaka, Makoto; Nankawa, Takuya

    2013-01-01

    Highlights: ► Cu II HCF III film was developed for Cs removal in an electrochemical adsorption system (EAS). ► Hydrophilic coating was achieved by covering ferrocyanide ions on Cu II HCF III nanoparticles. ► Cs uptake and elution can be simply controlled by the EAS. ► EAS can selectively separate Cs in the presence of coexisting alkaline cations. ► Effective Cs removal can be adopted in a large pH range of 0.3–9.2. - Abstract: A novel electrochemical adsorption system using a nanoparticle film of copper (II) hexacyanoferrate (III) was proposed for selectively removing cesium from wastewater. This system can be used for cesium separation without extra chemical reagents or any filtration treatment. Cesium uptake and elution can be simply controlled by switching the applied potentials between anodes and cathodes. Data from batch kinetic studies well fitted the intraparticle diffusion equation, reflecting a two-step process: a steepest ascent portion followed by a plateau extending to the equilibrium. The effective cesium removal with a high distribution coefficient (K d > 5 × 10 5 mL/g) can be adopted in a large pH range from 0.3 to 9.2, and in the presence of several diverse coexisting alkaline cations, suggesting it can be taken as a promising technology for actual nuclear wastewater treatment.

  18. Behaviour of cesium 134 and 137 in lake ecosystems

    International Nuclear Information System (INIS)

    Huebel, K.; Saenger, W.; Luensmann, W.

    1989-01-01

    The time dependent cesium activity concentration observed in surface water samples from South Bavarian lakes after the Chernobyl accident is analysed by use of a two-compartment model simulating the accidental transport of radiocesium from surface water to suspended particles. (orig.)

  19. Process for cesium decontamination and immobilization

    Science.gov (United States)

    Komarneni, Sridhar; Roy, Rustum

    1989-01-01

    Cesium can be selectively recovered from a nuclear waste solution containing cesium together with other metal ions by contact with a modified phlogopite which is a hydrated, sodium phlogopite mica. Once the cesium has entered the modified phlogopite it is fixed and can be safely stored for long periods of time.

  20. Methods for eluting radiocesium from zeolite ion exchange material in a column in the TMI-2 reactor containment building

    International Nuclear Information System (INIS)

    Knauer, J.B.; Campbell, D.O.; Collins, E.D.; King, L.J.

    1982-07-01

    Two alternative procedures were evaluated at Oak Ridge National Laboratory for potential use in eluting the radiocesium from Linde Ionsiv IE-95 zeolite in the pushcart ion exchange column in the TMI-2 containment building. The elution mechanism was iosotopic exchange of the radiocesium with stable cesium. Small zeolite ion exchange columns that had been loaded during ORNL tests of the Submerged Demineralizer System (SDS) flowsheet were eluted during these tests. One column was eluted using 0.25 M CsNO 3 , and a second column was eluted using 0.25 M CsH 2 BO 3 . Both eluent solutions were effective for removing the cesium. The 0.25 CsNO 3 eluent removed approx. 91% of the 137 Cs in 20 bed volumes and approx. 92% in 37.5 bed volumes. The 0.25 M CsH 2 BO 3 eluent removed approx. 82% of the 137 Cs in 20 bed volumes and approx. 85% in 40 bed volumes. In both cases, the radiation levels on the columns were reduced by a factor of approx. 30

  1. Effect of electrolytes concentration on recovery of cesium from AMP-PAN by Electrodialysis-Ion Exchange (EDIX)

    International Nuclear Information System (INIS)

    Mahendra, Ch.; Rajan, K.K.; SatyaSai, P.M.; Anand Babu, C.

    2014-01-01

    Cesium from the simulated acidic waste solution was separated using Ammonium Molybdophosphate (AMP) - Polyacrylonitrile (PAN) ion exchange resin in column operations. Electrodialysis - Ion exchange (EDIX) has been tried for the recovery of cesium from the AMP-PAN which was saturated with cesium. The electrodialysis setup consists of three compartments; cesium loaded AMP-PAN is placed in the middle compartment and is separated from the anode and cathode compartments by cation exchange membranes. Ammonium sulphate was used as anolyte and HNO 3 as catholyte. 0.1N HNO 3 was circulated in the middle compartment containing AMP-PAN to keep the resin in acidic form. On application of potential, the ammonium ions from the anode compartment migrate towards cathode through the middle compartment where they exchange with cesium ions on the resin and the exchanged cesium ions migrate towards cathode to get concentrated. Some part of cesium is recovered in the middle compartment due to convection. Cesium recovery from the AMP-PAN in the electrodialysis setup was studied at different anolyte and catholyte concentrations. All the experiments were carried out at constant current density of 40 mA/cm 2 for 15h. It was found that more than 50% of cesium recovery was observed for all the experiments studied and recovery percentage increased with increasing the anolyte concentration. It was observed that the electrolytes concentration affects the voltage drop across the cell

  2. Small-Scale Ion Exchange Removal of Cesium and Technetium from Hanford Tank 241-AN-102

    International Nuclear Information System (INIS)

    Hassan, N.M.

    2000-01-01

    The pretreatment process for BNFL, Inc.'s Hanford River Protection Project is to provide decontaminated low activity waste and concentrated eluate streams for vitrification into low and high activity waste glass, respectively. The pretreatment includes sludge washing, filtration, precipitation, and ion exchange processes to remove entrained solids, cesium, transuranics, technetium, and strontium. The cesium (Cs-137) and technetium (Tc-99) ion exchange removal is accomplished by using SuperLig 644, and 639 resins from IBC Advanced Technologies, American Fork, Utah. The resins were shown to selectively remove cesium and technetium (as anionic pertechnetate ) from alkaline salt solutions. The efficiency of ion exchange column loading and elution is a complex function involving feed compositions, equilibrium and kinetic behavior of ion exchange resins, diffusion, and the ionic strength and pH of the aqueous solution. A previous experimental program completed at the Savannah River Tech nology Center2 demonstrated the conceptualized flow sheet parameters with an Envelope C sample from Hanford Tank 241-AN-107. Those experiments also included determination of Cs and Tc batch distribution coefficients by SuperLig 644 and 639 resins and demonstration of small-scale column breakthrough and elution. The experimental findings were used in support of preliminary design bases and pretreatment flow sheet development by BNFL, Inc

  3. Equilibrium, kinetic and thermodynamic study of cesium adsorption onto nanocrystalline mordenite from high-salt solution.

    Science.gov (United States)

    Lee, Keun-Young; Park, Minsung; Kim, Jimin; Oh, Maengkyo; Lee, Eil-Hee; Kim, Kwang-Wook; Chung, Dong-Yong; Moon, Jei-Kwon

    2016-05-01

    In this study, the equilibrium, kinetics and thermodynamics of cesium adsorption by nanocrystalline mordenite were investigated under cesium contamination with high-salt solution, simulating the case of an operation and decommissioning of nuclear facilities or an accident during the processes. The adsorption rate constants were determined using a pseudo second-order kinetic model. The kinetic results strongly demonstrated that the cesium adsorption rate of nano mordenite is extremely fast, even in a high-salt solution, and much faster than that of micro mordenite. In the equilibrium study, the Langmuir isotherm model fit the cesium adsorption data of nano mordenite better than the Freundlich model, which suggests that cesium adsorption onto nano mordenite is a monolayer homogeneous adsorption process. The obtained thermodynamic parameters indicated that the adsorption involved a very stable chemical reaction. In particular, the combination of rapid particle dispersion and rapid cesium adsorption of the nano mordenite in the solution resulted in a rapid and effective process for cesium removal without stirring, which may offer great advantages for low energy consumption and simple operation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Cesium Eluate Evaporation Solubility and Physical Property Behavior

    International Nuclear Information System (INIS)

    Pierce, R.A.

    2003-01-01

    The baseline flowsheet for low activity waste (LAW) in the Hanford River Protection Project (RPP) Waste Treatment Plant (WTP) includes pretreatment of supernatant by removing cesium using ion exchange. When the ion exchange column is loaded, the cesium will be eluted with a 0.5M nitric acid (HNO3) solution to allow the column to be conditioned for re-use. The cesium eluate solution will then be concentrated in a vacuum evaporator to minimize storage volume and recycle HNO3. To prevent the formation of solids during storage of the evaporator bottoms, criteria have been set for limiting the concentration of the evaporator product to 80 percent of saturation at 25 degrees C. A fundamental element of predicting evaporator product solubility is to collect data that can be used to estimate key operating parameters. The data must be able to predict evaporator behavior for a range of eluate concentrations that are evaporated to the point of precipitation. Parameters that were selected for modeling include solubility, density, viscosity, thermal conductivity, and heat capacity. Of central importance is identifying the effect of varying feed components on overall solubility. The point of solubility defines the upper limit for eluate evaporation operations and liquid storage. The solubility point also defines those chemical compounds that have the greatest effects on physical properties. Third, solubility behavior identifies intermediate points where physical property data should be measured for the database. Physical property data (density, viscosity, thermal conductivity, and heat capacity) may be an integral part of tracking evaporator operations as they progress toward their end point. Once the data have been collected, statistical design software can develop mathematical equations that estimate solubility and other physical properties

  5. Decorporation of cesium-137; Decorporation du cesium-137

    Energy Technology Data Exchange (ETDEWEB)

    Le Fleche, Ph.; Destombe, C.; Grasseau, A.; Mathieu, J.; Chancerelle, Y.; Mestries, J.C. [GMR, Direction des Recherches, Etudes et Techniques, 94 - Arcueil (France)

    1997-12-31

    Cesium radio-isotopes, especially cesium-137 ({sup 137}Cs) are among the radionuclides of main importance produced by a fission reaction in reactor or a nuclear weapon explosion. In the environment, {sup 137}Cs is a major contaminant which can cause severe {beta}, {gamma}irradiations and contaminations. {sup 137}Cs is distributed widely and relatively uniformly throughout the body with the highest concentration in skeletal muscles. A treatment becomes difficult afterwards. The purposes of this report are Firstly to compare the Prussian blue verses cobalt and potassium ferrocyanide (D.I. blue) efficiency for the {sup 137}Cs decorporation and secondly to assess a chronological treatment with D.I. blue. (author)

  6. Strontium-90 and cesium-137 in freshwater (from September, 1982, to December, 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in fresh water measured at 4 locations across Japan from September to December, 1982, are given in pCi/l, respectively. The methods of the collection and pretreatment of samples, the preparation of samples for analysis, the separation of strontium-90 and cesium-137, and the counting are also described. The sample was passed through a cation exchange column. Strontium and cesium were eluted with hydrochloric acid from the cation exchange column. The sample solution prepared was neutralized with sodium hydroxide. After sodium carbonate was added, the precipitate of strontium and calcium carbonates was separated. The supernatant solution was retained for cesium-137 determination. After the radiochemical separation, the mounted precipitate was counted for activity using a low background beta counter normally for 60 min. The radioactivity ranged 0.08 to 0.22 pCi/l for Sr-90 and 0.003 to 0.020 pCi/l for Cs-137 in the freshwater. (J.P.N.)

  7. Strontium-90 and cesium-137 in service water (from June, 1982, to December, 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in service water measured at 19 locations across Japan from June to December, 1982, are given in pCi/l, respectively. The methods of the collection and pretreatment of samples, the preparation of samples for analysis, the separation of strontium-90 and cesium-137, and the counting are also described. Service water was collected at an intake of the water-treatment plant and at the tap. The sample was then passed through a cation exchange column. Strontium and cesium were eluted with hydrochloric acid from the cation exchange column. The sample solution prepared was neutralized with sodium hydroxide. After sodium carbonate was added, the precipitate of strontium and calcium carbonates was separated. The supernatant solution was retained for cesium-137 determination. After the radiochemical separation, the mounted precipitate was counted for activity using a low background beta counter normally for 60 min. The radioactivity ranged 0.01 to 0.10 pCi/l for Sr-90 and 0.001 to 0.010 pCi/l for Cs-137 in the service water. (J.P.N.)

  8. Cesium-137, a drama recounted

    International Nuclear Information System (INIS)

    Vieira, Suzane de Alencar

    2013-01-01

    The radiological accident with Cesium-137, which started on Goiania in 1987, did not stop with the end of radiological contamination and continues in a judicial, scientific and narrative process of identification and recognition of new victims. The drama occupies a central place on the dynamics of radiological event, as it extends its limits, inflects its intensity and updates the event. As a narrative of the event, the ethnography incorporates and brings up to date the drama as an analysis landmark and the description of the theme as it is absorbed by a dramatic process. Cesium-137, a drama recounted is a textual experimentation based on real events and characters picked out from statements reported in various narratives about the radiological accident. (author)

  9. Extraction of radioactive cesium from tea leaves

    International Nuclear Information System (INIS)

    Yano, Yukiko; Kubo, M. Kenya; Higaki, Shogo; Hirota, Masahiro; Nomura, Kiyoshi

    2011-01-01

    Radioactive contamination of foodstuffs attributed to the Fukushima Daiichi nuclear disaster has become a social problem. This study investigated the extraction of radioactive cesium from the contaminated leaves to the tea. The green tea was brewed twice reusing the same leaves to study the difference in extraction of cesium between the first and second brew. Moreover, the extraction of cesium was studied in correlation to brewing time. The concentration of radioactive cesium was determined with gamma spectrometry, and the concentration of caffeine was determined with absorption spectrometry. About 40% of cesium was extracted from leaves in the first brew, and about 80% was extracted in the second brew. The extraction of cesium increased over time, and it reached about 80% after 10 minutes brew. The ratio of radioactive cesium to caffeine decreased linearly over time. This study revealed that the extraction of cesium was higher for the second brew, and a rapid increase in extraction was seen as the tea was brewed for 6 minutes and more. Therefore, the first brew of green tea, which was brewed within 5 minutes, contained the least extraction of radioactive cesium from the contaminated leaves. (author)

  10. Effect of desorption kinetics on colloid-facilitated transport of contaminants: Cesium, strontium, and illite colloids

    Science.gov (United States)

    Turner, Ned B.; Ryan, Joseph N.; Saiers, James E.

    2006-12-01

    To examine the importance of desorption kinetics to colloid-facilitated transport, we conducted column experiments comparing the transport of cesium and strontium through a saturated quartz sand porous medium in the absence and presence of illite colloids at two ionic strengths. Because cesium desorption from illite was anticipated to be slower than that of strontium, we expected to see a contrast in the colloid-facilitated transport of the cations. A model of colloid-facilitated transport accounting for second-order cation adsorption to and desorption from the quartz, second-order cation adsorption to and desorption from fast and slow sites on the illite colloids, and second-order colloid deposition to and release from the quartz accurately simulated the cation transport in the absence and presence of the illite colloids. The column results and model simulations revealed that cesium desorption was indeed slower than strontium desorption and that this contrast in desorption kinetics resulted in greater colloid-facilitated transport of the cesium. The desorption of both cations was slow relative to the rate of advection. The fast and slow sites on the illite colloids behaved like planar and frayed edge sites typically identified for cesium adsorption to illite. The amount of cesium adsorbed to the slow, or frayed edge, sites was similar to the frayed edge site density of illite estimated by other researchers.

  11. Electrodriven selective transport of Cs+ using chlorinated cobalt dicarbollide in polymer inclusion membrane: a novel approach for cesium removal from simulated nuclear waste solution.

    Science.gov (United States)

    Chaudhury, Sanhita; Bhattacharyya, Arunasis; Goswami, Asok

    2014-11-04

    The work describes a novel and cleaner approach of electrodriven selective transport of Cs from simulated nuclear waste solutions through cellulose tri acetate (CTA)/poly vinyl chloride (PVC) based polymer inclusion membrane. The electrodriven cation transport together with the use of highly Cs+ selective hexachlorinated derivative of cobalt bis dicarbollide, allows to achieve selective separation of Cs+ from high concentration of Na+ and other fission products in nuclear waste solutions. The transport selectivity has been studied using radiotracer technique as well as atomic emission spectroscopic technique. Transport studies using CTA based membrane have been carried out from neutral solution as well as 0.4 M HNO3, while that with PVC based membrane has been carried out from 3 M HNO3. High decontamination factor for Cs+ over Na+ has been obtained in all the cases. Experiment with simulated high level waste solution shows selective transport of Cs+ from most of other fission products also. Significantly fast Cs+ transport rate along with high selectivity is an interesting feature observed in this membrane. The current efficiency for Cs+ transport has been found to be ∼100%. The promising results show the possibility of using this kind of electrodriven membrane transport methods for nuclear waste treatment.

  12. Effects of acute and chronic experimental contamination on direct cesium 137 uptake by the eel, Anguilla anguilla L

    International Nuclear Information System (INIS)

    Foulquier, Luc; Lambrechts, Alain.

    1982-03-01

    This study covers the effects of different types of contamination on direct cesium 137 uptake by the eel. In the first experiment (acute contamination), simulating a waste discharge, the fish were kept in water with a rapidly decreasing cesium 137 activity. In a second experiment (chronic contamination), the water activity increased constantly, simulating increasing waste frequency and activity levels. Irrespective of the type of contamination, radiocesium retention by eels is low ( [fr

  13. Decontamination of radioactive cesium in the soil

    International Nuclear Information System (INIS)

    Yanaga, Makoto; Oishi, Ayumi

    2013-01-01

    Decontamination of radioactive cesium from the agricultural soil was attempted by extraction method using potassium solution. The result of experiments using the soil artificially contaminated with 137 Cs showed that radioactive cesium was extracted by potassium solution. However, the extraction rate decreased when time after contamination passed. (author)

  14. Cesium ion exchange using actual waste: Column size considerations

    International Nuclear Information System (INIS)

    Brooks, K.P.

    1996-04-01

    It is presently planned to remove cesium from Hanford tank waste supernates and sludge wash solutions using ion exchange. To support the development of a cesium ion exchange process, laboratory experiments produced column breakthrough curves using wastes simulants in 200 mL columns. To verify the validity of the simulant tests, column runs with actual supernatants are being planned. The purpose of these actual waste tests is two-fold. First, the tests will verify that use of the simulant accurately reflects the equilibrium and rate behavior of the resin compared to actual wastes. Batch tests and column tests will be used to compare equilibrium behaviors and rate behaviors, respectively. Second, the tests will assist in clarifying the negative interactions between the actual waste and the ion exchange resin, which cannot be effectively tested with simulant. Such interactions include organic fouling of the resin and salt precipitation in the column. These effects may affect the shape of the column breakthrough curve. The reduction in column size also may change the shape of the curve, making the individual effects even more difficult to sort out. To simplify the evaluation, the changes due to column size must be either understood or eliminated. This report describes the determination of the column size for actual waste testing that best minimizes the effect of scale-down. This evaluation will provide a theoretical basis for the dimensions of the column. Experimental testing is still required before the final decision can be made. This evaluation will be confined to the study of CS-100 and R-F resins with NCAW simulant and to a limited extent DSSF waste simulant. Only the cesium loading phase has been considered

  15. Thermal properties of cesium molybdate

    International Nuclear Information System (INIS)

    Minato, Kazuo; Fukuda, Kousaku; Takano, Masahide; Sato, Seichi; Ohashi, Hiroshi

    1996-01-01

    Cesium is one of the most important fission products to aid in the understanding and prediction of the behavior of oxide nuclear fuels because of its high mobility, chemical reactivity, and large yield. In postirradiation examinations of the Phoenix reactor fuel pins, the accumulation of cesium and molybdenum between the fuel pellet and cladding was observed, though the chemical form was not determined. In the thermodynamic analyses of chemical states of fission products, Cs 2 MoO 4 was often predicted to exist as a stable compound in oxide fuels. The Cs 2 MoO 4 compound is thermodynamically stable under the conditions of light water reactors, fast breeder reactors, and high-temperature gas-cooled reactors. In the Cs-Mo-O system several phases have been found, and the structural and thermodynamic properties were studied. At room temperature, Cs 2 MoO 4 has an orthorhombic structure and a phase transition occurs at 841 K to a hexagonal structure. Both structures are expected to exist in the fuel, depending on the fuel temperature. However, no data has been available on the thermal properties of CS 2 MoO 4 . In the current work, the thermal expansion and thermal conductivity of Cs 2 MoO 4 were determined, which are the basic data needed to understand and predict the fuel/clad mechanical interaction and fuel temperature

  16. Intense nonrelativistic cesium ion beam

    International Nuclear Information System (INIS)

    Lampel, M.C.

    1984-01-01

    The Heavy Ion Fusion group at Lawrence Berkeley Laboratory has constructed the One Ampere Cesium injector as a proof of principle source to supply an induction linac with a high charge density and high brightness ion beam. This is studied here. An electron beam probe was developed as the major diagnostic tool for characterizing ion beam space charge. Electron beam probe data inversion is accomplished with the EBEAM code and a parametrically adjusted model radial charge distribution. The longitudinal charge distribution was not derived, although it is possible to do so. The radial charge distribution that is derived reveals an unexpected halo of trapped electrons surrounding the ion beam. A charge fluid theory of the effect of finite electron temperature on the focusing of neutralized ion beams (Nucl Fus. 21, 529(1981)) is applied to the problem of the cesium beam final focus at the end of the injector. It is shown that the theory's predictions and assumptions are consistent with the experimental data, and that it accounts for the observed ion beam radius of approx.5 cm and the electron halo, including the determination of an electron Debye length of approx.10 cm

  17. Multiphoton ionization of atomic cesium

    International Nuclear Information System (INIS)

    Compton, R.N.; Klots, C.E.; Stockdale, J.A.D.; Cooper, C.D.

    1984-01-01

    We describe experimental studies of resonantly enhanced multi-photon ionization (MPI) of cesium atoms in the presence and absence of an external electric field. In the zero-field studies, photo-electron angular distributions for one- and two-photon resonantly enhanced MPI are compared with the theory of Tang and Lambropoulos. Deviations of experiment from theory are attributed to hyperfine coupling effects in the resonant intermediate state. The agreement between theory and experiment is excellent. In the absence of an external electric field, signal due to two-photon resonant three-photon ionization of cesium via np states is undetectable. Application of an electric field mixes nearby nd and ns levels, thereby inducing excitation and subsequent ionization. Signal due to two-photon excitation of ns levels in field-free experiments is weak due to their small photoionization cross section. An electric field mixes nearby np levels which again allows detectable photo-ionization signal. For both ns and np states the ''field induced'' MPI signal increases as the square of the electric field for a given principal quantum number and increases rapidly with n for a given field strength

  18. Application of Cesium isotopes in daily life

    International Nuclear Information System (INIS)

    Jordao, B.O.; Quaresma, D.S.; Carvalho, R.J.; Peixoto, J.G.P.

    2014-01-01

    In the world of science, the desire of the scientific community to discover new chemical elements is crucial for the development of new technologies in various fields of knowledge. And the main chemical element addressed by this article is Cesium, but specifically 133 Cesium isotope and radioisotope 137 Cesium, exemplifying their physical and chemical characteristics, and their applications. This article will also show how these isotopes have provided researchers a breakthrough in the field of radiological medicine and in time and frequency metrology. (author)

  19. Development program for magnetically assisted chemical separation: Evaluation of cesium removal from Hanford tank supernatant

    International Nuclear Information System (INIS)

    Nunez, L.; Buchholz, B.A.; Ziemer, M.; Dyrkacz, G.; Kaminski, M.; Vandegrift, G.F.; Atkins, K.J.; Bos, F.M.; Elder, G.R.; Swift, C.A.

    1994-12-01

    Magnetic particles (MAG*SEP SM ) coated with various absorbents were evaluated for the separation and recovery of low concentrations of cesium from nuclear waste solutions. The MAG*SEP SM particles were coated with (1) clinoptilolite, (2) transylvanian volcanic tuff, (3) resorcinol formaldehyde, and (4) crystalline silico-titanate, and then were contacted with a Hanford supernatant simulant. Particles coated with the crystalline silico-titanate were identified by Bradtec as having the highest capacity for cesium removal under the conditions tested (variation of pH, ionic strength, cesium concentration, and absorbent/solution ratio). The MAG*SEP SM particles coated with resorcinol formaldehyde had high distribution ratios values and could also be used to remove cesium from Hanford supernant simulant. Gamma irradiation studies were performed on the MAG*SEP SM particles with a gamma dose equivalent to 100 cycles of use. This irradiation decreased the loading capacity and distribution ratios for the particles by greater than 75%. The particles demonstrated high sensitivity to radiolytic damage due to the degradation of the polymeric regions. These results were supported by optical microscopy measurements. Overall, use of magnetic particles for cesium separation under nuclear waste conditions was found to be marginally effective

  20. Sintered wire cesium dispenser photocathode

    Science.gov (United States)

    Montgomery, Eric J; Ives, R. Lawrence; Falce, Louis R

    2014-03-04

    A photoelectric cathode has a work function lowering material such as cesium placed into an enclosure which couples a thermal energy from a heater to the work function lowering material. The enclosure directs the work function lowering material in vapor form through a low diffusion layer, through a free space layer, and through a uniform porosity layer, one side of which also forms a photoelectric cathode surface. The low diffusion layer may be formed from sintered powdered metal, such as tungsten, and the uniform porosity layer may be formed from wires which are sintered together to form pores between the wires which are continuous from the a back surface to a front surface which is also the photoelectric surface.

  1. Cesium-137: A physiological disruptor?

    International Nuclear Information System (INIS)

    Souidi, Maamar; Grison, Stephane; Dublineau, Isabelle; Aigueperse, Jocelyne; Lestaevel, Philippe

    2013-01-01

    Today, radiation protection is a major issue for the nuclear industry throughout the world, particularly in France. The 2011 disaster of Fukushima Dai-ichi has brought back to public attention questions about the risks associated with nuclear power for civilian purposes. The risk of accidental release of radioactive molecules, including cesium-137 ( 137 Cs), from these facilities cannot be completely eliminated. The non-cancer-related health consequences of chronic exposure to this radionuclide remain poorly understood. After absorption, cesium is distributed throughout the body. The toxicity of 137 Cs is due mainly to its radiological properties. Studies in humans report that 137 Cs impairs the immune system and induces neurological disorders. Children appear more susceptible than adults to its toxic effects. In animals, and most particularly in rodents, low-dose internal contamination disrupts the sleep-wake cycle, but without behavioural disorders. Impairment of the cardiovascular system has also been observed. Physiologic systems such as the metabolism of vitamin D, cholesterol and steroid hormones are altered, although without leading to the emergence of diseases with clinical symptoms. Recently, a metabolomics study based on contamination levels comparable to those around Chernobyl after the accident showed that it is possible to identify individual rats chronically exposed to low doses of 137 Cs, even though the exposure was too low to affect the standard clinical markers. In conclusion, the scientific evidence currently available, particularly that from experimental animal models exposed to chronic contamination, suggests that 137 Cs is likely to affect many physiologic and metabolic functions. Thus, it could contribute, with other artificial substances in the environment, to increasing the risk of developing non-cancer diseases in some regions. (authors)

  2. Strontium-90 and cesium-137 in service water from June to December, 1981

    International Nuclear Information System (INIS)

    1981-01-01

    Service water, 100 l each, was collected at an intake of a water treatment plant and at a tap after water was left running for five minutes. The carriers of strontium and cesium were added to water immediately after sampling, and the sample was vigorously stirred and filtered. Then it was passed through a cation exchange column at a rate of 80 ml/min. Strontium and cesium were eluted with hydrochloric acid from the cation exchange column, and separated. After the radiochemical separation, the mounted precipitates were counted for activity using low background beta counters normally for 60 min. Net sample counting rates were corrected for counter efficiency, recovery, self absorption and decay to obtain the content of strontium-90 and cesium-137 radioactivity per sample aliquot. From the results, concentrations of these nuclides in the original sample were calculated. The maximum values obtained were 0.29 pCi/l of Sr-90 in Kyoto in August, 1981, and 0.02 pCi/l of Cs-137 in Kyoto in August and in Inuyama in December, 1981, in case of source water. In case of tap water, they were 0.18 pCi/l of Sr-90 in Kobe in December, 1981, and 0.02 pCi/l of Cs-137 in Kyoto in August, 1981. (Kako, I.)

  3. Removal of cesium and separation of strontium the analysis of the leachate of spent fuel

    International Nuclear Information System (INIS)

    Kim, Seung Soo; Chun, Kwan Sik; Kang, Chul Hyung

    2002-01-01

    The selective removal of cesium by ammonium molybdophosphate (AMP) was studied in order to reduce an interference by high radioactivity of cesium on the determination of low radioactive elements in leachate of spent fuel. The removal of Cs, U, Ce, La, Co, Na Sr and K was investigated for the leachate and the bentonite in contact with a spent fuel. More than 90% of cesium was removed by AMP and Ca, Na, Co and Sr was remained in 0.1M HNO 3 . However, three valence elements such as La and Ce were also removed by AMP. Though a little of potassium of the bentonite components was adsorbed on AMP, the potassium in the bentonite solution diluted to its concentration in a real sample would not affect the capacity of AMP greatly. From another experiment for the separation of strontium as a leaching indicator of spent fuel, the recovery of strontium in 8.0 M HNO 3 solution by using Sr-resin (Eichrom, P/N SR-B50-A) was more than 95% by eluting with 0.05 M HNO 3

  4. Development of electrochemical ion exchange electrodes for the treatment of wastes containing chromium or cesium ions

    International Nuclear Information System (INIS)

    Manosso, Helena Cristina

    2006-01-01

    Nowadays, environmental preservation using technologies that do not attack it, generating non-toxic residues and reduced volumes, has been discussed. Hazardous effluents, containing metals, as chromium, have been poured in the soils and rivers, degrading the water. Not different are the problems originated from some nuclear activities that generate wastes, as in chemical research laboratories. Although those wastes are not poured in the environment, sometimes they are inadequately stored, what can cause serious accidents. With the purpose of solving this problem, there are some techniques to waste treatment, between them there is the electrochemical ion exchange (EIX). EIX is an advanced process that has advantages over traditional ion exchange and the fact of using the electron as the only reagent, reduces the volume of the solution to be treated. This technique consists of development of an electrode, where an ion exchanger is physically incorporated in an electrode structure with a binder. In this study, cationic resin Amberlite CG-50 and zirconium phosphate have been chosen for the separation of chromium and cesium from waste, respectively. They were chosen because they present high chemical stability in oxidizing media and at ionizing radiation. The quantity of charcoal, graphite and binder used in formulation of electrode have been studied either. Before choosing the best electrode, it was verified sorption percentage of 99,3% for chromium and 99,8% for cesium. The greater advantage of this process is the total elution of chromium as much as cesium, without reagents addition, being possible to reuse the electrode without losing its capacity. Beside on the results, a continuous process for the wastes containing Cr and Cs, using a flux electrolytic cell (CELFLUX) of high retention capacity, was presented. The high efficiency of this cell for both retention and elution, leading to an important reduction of waste volume, and, every more, making possible the

  5. Cesium ion bombardment of metal surfaces

    International Nuclear Information System (INIS)

    Tompa, G.S.

    1986-01-01

    The steady state cesium coverage due to cesium ion bombardment of molybdenum and tungsten was studied for the incident energy range below 500 eV. When a sample is exposed to a positive ion beam, the work function decreases until steady state is reached with a total dose of less than ≅10 16 ions/cm 2 , for both tungsten and molybdenum. A steady state minimum work function surface is produced at an incident energy of ≅100 eV for molybdenum and at an incident energy of ≅45 eV for tungsten. Increasing the incident energy results in an increase in the work function corresponding to a decrease in the surface coverage of cesium. At incident energies less than that giving the minimum work function, the work function approaches that of cesium metal. At a given bombarding energy the cesium coverage of tungsten is uniformly less than that of molybdenum. Effects of hydrogen gas coadsorption were also examined. Hydrogen coadsorption does not have a large effect on the steady state work functions. The largest shifts in the work function due to the coadsorption of hydrogen occur on the samples when there is no cesium present. A theory describing the steady-state coverage was developed is used to make predictions for other materials. A simple sticking and sputtering relationship, not including implantation, cannot account for the steady state coverage. At low concentrations, cesium coverage of a target is proportional to the ratio of (1 - β)/γ where β is the reflection coefficient and γ is the sputter yield. High coverages are produced on molybdenum due to implantation and low backscattering, because molybdenum is lighter than cesium. For tungsten the high backscattering and low implantation result in low coverages

  6. Preferential removal and immobilization of stable and radioactive cesium in contaminated fly ash with nanometallic Ca/CaO methanol suspension.

    Science.gov (United States)

    Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Sakita, Shogo; Simion, Cristian

    2014-08-30

    In this work, the capability of nanometallic Ca/CaO methanol suspension in removing and/or immobilizing stable ((133)Cs) and radioactive cesium species ((134)Cs and (137)Cs) in contaminated fly ash was investigated. After a first methanol and second water washing yielded only 45% of (133)Cs removal. While, after a first methanol washing, the second solvent with nanometallic Ca/CaO methanol suspension yielded simultaneous enhanced removal and immobilization about 99% of (133)Cs. SEM-EDS analysis revealed that the mass percent of detectable (133)Cs on the fly ash surface recorded a 100% decrease. When real radioactive cesium contaminated fly ash (containing an initial 14,040Bqkg(-1)(134)Cs and (137)Cs cumulated concentration) obtained from burning wastes from Fukushima were reduced to 3583Bqkg(-1) after treatment with nanometallic Ca/CaO methanol suspension. Elution test conducted on the treated fly ash gave 100BqL(-1) total (134)Cs and (137)Cs concentrations in eluted solution. Furthermore, both ash content and eluted solution concentrations of (134)Cs and (137)Cs were much lower than the Japanese Ministry of the Environment regulatory limit of 8000Bqkg(-1) and 150BqL(-1) respectively. The results of this study suggest that the nanometallic Ca/CaO methanol suspension is a highly potential amendment for the remediation of radioactive cesium-contaminated fly ash. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Randomized comparison of sirolimus eluting, and biolimus eluting bioresorbable polymer stents

    DEFF Research Database (Denmark)

    Andreasen, Lene N; Holm, Niels R; Balleby, Ida R

    2018-01-01

    Aims: To show non-inferiority of the 67- or 87 µm thick, sirolimus-eluting Orsiro drug eluting stent (DES) to the 122 µm thick, biolimus-eluting Nobori DES regarding size of vessel lumen outside the stent at 13-month follow-up. Methods and results: This study was a substudy to the SORT-OUT VII tr...

  8. Physical Property Modeling of Concentrated Cesium Eluate Solutions, Part I - Derivation of Models

    Energy Technology Data Exchange (ETDEWEB)

    Choi, A.S.; Pierce, R. A.; Edwards, T. B.; Calloway, T. B.

    2005-09-15

    Major analytes projected to be present in the Hanford Waste Treatment Plant cesium ion-exchange eluate solutions were identified from the available analytical data collected during radioactive bench-scale runs, and a test matrix of cesium eluate solutions was designed within the bounding concentrations of those analytes. A computer model simulating the semi-batch evaporation of cesium eluate solutions was run in conjunction with a multi-electrolyte aqueous system database to calculate the physical properties of each test matrix solution concentrated to the target endpoints of 80% and 100% saturation. The calculated physical properties were analyzed statistically and fitted into mathematical expressions for the bulk solubility, density, viscosity, heat capacity and volume reduction factor as a function of temperature and concentration of each major analyte in the eluate feed. The R{sup 2} of the resulting physical property models ranged from 0.89 to 0.99.

  9. 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

  10. Elution behaviors of elements from the hair

    International Nuclear Information System (INIS)

    Akashi, Junko; Fukushima, Ichiro; Imahori, Akira

    1981-01-01

    The elution of the neutron activated elements out of hair soaked in some organic solvents and EDTA solution was studied. Soakage of the hair sample, which was washed with water and acetone in advance as IAEA's proposal, in ether and acetone for 30 minutes each resulted in no elution of Hg, Zn, Co and Se. Elution of Zn and Co from the powdered hair sample soaked in 0.1 M EDTA solution was rapid, while Zn did not elute out from the cut hair (2 -- 3 mm length) on the same condition. Hg, Se and Au were not eluted out by 0.1 M EDTA solution in the both case of cut hair and of powdered hair. Br was removed by 0.1 M EDTA solution from the cut hair and from the powdered hair with equal ease. (author)

  11. Radioactive cesium in Finnish mushrooms; Radioaktiivinen cesium Suomen ruokasienissae

    Energy Technology Data Exchange (ETDEWEB)

    Kostiainen, E.; Ylipieti, J.

    2010-02-15

    Surveillance of radioactive cesium in Finnish mushrooms was started in 1986 at STUK. Results of the surveillance programs carried out in Lapland and other parts of Finland are given in this report. More than 2000 samples of edible mushrooms have been analysed during 1986-2008. The 137Cs detected in the mushrooms mainly originates from the 137Cs deposition due to the accident at the Chernobyl nuclear power plant in 1986. The 137Cs concentrations of mushrooms in the end of 1970s and in the beginning of 1980s varied from some ten to two hundred becquerels per kilogram originating from the nuclear weapon test period. The uneven division of the Chernobyl fallout is seen in the areal variation of 137Cs concentrations of mushrooms, the 137Cs concentrations being about tenfold in the areas with the highest deposition compared to those where the deposition was lowest. After the Chernobyl accident the maximum values in the 137Cs concentrations were reached during 1987-88 among most species of mushrooms. The 137Cs concentrations have decreased slowly, being in 2008 about 40 per cent of the maximum values. The 137Cs concentrations may be tenfold in the mushroom species with high uptake of cesium (Rozites caperatus, Hygrophorus camarophyllus, Lactarius trivialis) compared to the species with low uptake (Albatrellus ovinus, Leccinum sp.) picked in the same area. The 137Cs contents in certain species of commercial mushrooms in Finland still exceed the maximum permitted level, 600 Bq/kg, recommended to be respected when placing wild game, wild berries, wild mushrooms and lake fish on the market (Commission recommendation 2003/274/Euratom). Therefore, the 137Cs concentrations of mushrooms should be measured before placing them on the market in the areas of the highest 137Cs deposition, except for Albatrellus ovinus, Boletus sp. and Cantharellus cibarius. The 137Cs concentrations of common commercial mushroom species, Cantharellus tubaeformis and Craterellus cornucopioides often

  12. Separation of cesium from aqueous solutions using alkylated tetraaryl borates

    International Nuclear Information System (INIS)

    Feldmaier, F.

    1991-01-01

    The water solubility of cesium tetraaryl borates was lowered by introducing hydrophobic aliphatic side chains into corresponding acid-resistant fluorosubstituted tetraaryl borates. This improved cesium spearability both in precipitation and in extraction from aqueous solutions. (orig.) [de

  13. Preferential removal and immobilization of stable and radioactive cesium in contaminated fly ash with nanometallic Ca/CaO methanol suspension

    International Nuclear Information System (INIS)

    Mallampati, Srinivasa Reddy; Mitoma, Yoshiharu; Okuda, Tetsuji; Sakita, Shogo; Simion, Cristian

    2014-01-01

    Graphical abstract: Schematic representation of possible mechanisms determining the Cs extraction and immobilization in fly ash during water, methanol or n-MCaS extraction. - Highlights: • nMCaS suspension for cesium extraction and immobilization in fly ash was developed. • Enhanced cesium immobilization was done by nanometallic Ca/CaO methanol suspension. • By SEM analysis the amount of cesium detectable on soil particle surface decreases. • Leachable cesium concentrations reduced, lower than the standard regulatory limit. • nMCaS unique and a highly potential amendment for the remediation of Cs. - Abstract: In this work, the capability of nanometallic Ca/CaO methanol suspension in removing and/or immobilizing stable ( 133 Cs) and radioactive cesium species ( 134 Cs and 137 Cs) in contaminated fly ash was investigated. After a first methanol and second water washing yielded only 45% of 133 Cs removal. While, after a first methanol washing, the second solvent with nanometallic Ca/CaO methanol suspension yielded simultaneous enhanced removal and immobilization about 99% of 133 Cs. SEM-EDS analysis revealed that the mass percent of detectable 133 Cs on the fly ash surface recorded a 100% decrease. When real radioactive cesium contaminated fly ash (containing an initial 14,040 Bq kg −1134 Cs and 137 Cs cumulated concentration) obtained from burning wastes from Fukushima were reduced to 3583 Bq kg −1 after treatment with nanometallic Ca/CaO methanol suspension. Elution test conducted on the treated fly ash gave 100 Bq L −1 total 134 Cs and 137 Cs concentrations in eluted solution. Furthermore, both ash content and eluted solution concentrations of 134 Cs and 137 Cs were much lower than the Japanese Ministry of the Environment regulatory limit of 8000 Bq kg −1 and 150 Bq L −1 respectively. The results of this study suggest that the nanometallic Ca/CaO methanol suspension is a highly potential amendment for the remediation of radioactive cesium

  14. Improvement of cesium retention in uranium dioxide by additional phases; Amelioration de la retention du cesium dans le dioxyde d`uranium au moyen de phases exogenes

    Energy Technology Data Exchange (ETDEWEB)

    Gamaury Dubois, S.

    1995-09-19

    The objective of this study is to improve the cesium retention in nuclear fuel. A bibliographic survey indicates that cesium is rapidly released from uranium dioxide in an accident condition. At temperatures higher than 1500 deg C or in oxidising conditions, our experiments show the difficulty of maintaining cesium inside simulated fuel. Two ternary systems are potentially interesting for the retention of cesium and to reduce the kinetics of release from the fuel: Cs{sub 2}O-Al{sub 2}O{sub 3}-SiO{sub 2} et Cs{sub 2}O-ZrO{sub 2}-SO{sub 2}. The compounds CsAISi{sub 2}O{sub 6} and Cs{sub 2}ZrSi{sub 6}O{sub 15} were studied from 1200 deg C to 2000 deg C by thermogravimetric analysis. The volumetric diffusion coefficients of cesium in these structures, in solid state as well as in liquid one, were measured. A fuel was sintered with (Al{sub 2}O{sub 3} + SiO{sub 2}) or (ZrO{sub 2} + SiO{sub 2}) and the intergranular phase was characterized. In the presence of (Al{sub 2}O{sub 3} + SiO{sub 2}), the sintering is realized at 1610 deg C in H{sub 2}. It is a liquid phase sintering. On the other end, with (ZrO{sub 2} + SiO{sub 2}), the sintering is a low temperature one in oxidising atmosphere. Finally, cesium containing simulated fuels were produced with these additives. According to the effective diffusion coefficients that were measured, the additives improved the retention of cesium. We have predicted the improvement that could be hoped for in a nuclear reactor, depending on the dispersion of the intergranular additives, the temperature and the degree of oxidation of the UO{sub 2+x}. We wait for a factor of 2 for x=0 and more than 8 for x=0.05, up to 2000 deg C. (author). 148 refs., 122 figs., 34 tabs.

  15. Cesium Salts of Phosphotungstic Acid: Comparison of Surface ...

    African Journals Online (AJOL)

    NICO

    acidity and lowest solubility in reaction media in comparison with the other cesium content salts. KEYWORDS. Polyoxometalates, cesium ... insoluble salt of HPA is cesium salt of tungstophosphoric acid,. CsxH3-xPW12O40 (CsxPW), a ... of Cs2CO3, very fine particles (precipitates) were formed to make the solution milky.

  16. Radioactive cesium in Finnish mushrooms

    International Nuclear Information System (INIS)

    Kostiainen, E.; Ylipieti, J.

    2010-02-01

    Surveillance of radioactive cesium in Finnish mushrooms was started in 1986 at STUK. Results of the surveillance programs carried out in Lapland and other parts of Finland are given in this report. More than 2000 samples of edible mushrooms have been analysed during 1986-2008. The 137 Cs detected in the mushrooms mainly originates from the 137 Cs deposition due to the accident at the Chernobyl nuclear power plant in 1986. The 137 Cs concentrations of mushrooms in the end of 1970s and in the beginning of 1980s varied from some ten to two hundred becquerels per kilogram originating from the nuclear weapon test period. The uneven division of the Chernobyl fallout is seen in the areal variation of 137 Cs concentrations of mushrooms, the 137 Cs concentrations being about tenfold in the areas with the highest deposition compared to those where the deposition was lowest. After the Chernobyl accident the maximum values in the 137 Cs concentrations were reached during 1987-88 among most species of mushrooms. The 137 Cs concentrations have decreased slowly, being in 2008 about 40 per cent of the maximum values. The 137 Cs concentrations may be tenfold in the mushroom species with high uptake of cesium (Rozites caperatus, Hygrophorus camarophyllus, Lactarius trivialis) compared to the species with low uptake (Albatrellus ovinus, Leccinum sp.) picked in the same area. The 137 Cs contents in certain species of commercial mushrooms in Finland still exceed the maximum permitted level, 600 Bq/kg, recommended to be respected when placing wild game, wild berries, wild mushrooms and lake fish on the market (Commission recommendation 2003/274/Euratom). Therefore, the 137 Cs concentrations of mushrooms should be measured before placing them on the market in the areas of the highest 137 Cs deposition, except for Albatrellus ovinus, Boletus sp. and Cantharellus cibarius. The 137 Cs concentrations of common commercial mushroom species, Cantharellus tubaeformis and Craterellus

  17. Partitioning of cesium in hydrofracture grouts

    International Nuclear Information System (INIS)

    Stinton, D.P.; McDaniel, E.W.; Weeren, H.O.

    1983-01-01

    Phase characterization of hydrofracture grouts was accomplished with the use of optical microscopy, scanning electron microscopy, x-ray diffraction, and β-γ autoradiography. A laboratory-produced sample containing 1 wt % stable cesium and an actual hydrofracture grout sheet obtained by core dirlling were examined during this work. The phases present in these samples were identified and cesium was found to be absorbed almost entirely by illite clay agglomerates. These clay agglomerates were tightly bound within the grout structure by hydrated calcium silicates. The β-γ autoradiography of the core-drilled sample verified that cesium and other radionuclides were trapped within the 20-year-old grout and had not migrated into trapped shale fragments. 14 references, 3 figures, 1 table

  18. Hanford waste encapsulation: strontium and cesium

    International Nuclear Information System (INIS)

    Jackson, R.R.

    1976-06-01

    The strontium and cesium fractions separated from high radiation level wastes at Hanford are converted to the solid strontium fluoride and cesium chloride salts, doubly encapsulated, and stored underwater in the Waste Encapsulation and Storage Facility (WESF). A capsule contains approximately 70,000 Ci of 137 Cs or 70,000 to 140,000 Ci of 90 Sr. Materials for fabrication of process equipment and capsules must withstand a combination of corrosive chemicals, high radiation dosages and frequently, elevated temperatures. The two metals selected for capsules, Hastelloy C-276 for strontium fluoride and 316-L stainless steel for cesium chloride, are adequate for prolonged containment. Additional materials studies are being done both for licensing strontium fluoride as source material and for second generation process equipment

  19. Effect of Cesium Pressure on Thermionic Stability

    Energy Technology Data Exchange (ETDEWEB)

    Schock, Alfred

    1969-08-01

    It is shown that under certain conditions of heat input, reservoir temperature, and load voltage or resistance a thermionic converter can equilibrate at two radically different operation points, corresponding to conditions of high and low cesium coverage. Moreover, abrupt transitions between these operating regimes, accompanied by a temperature rise of hundreds of degrees, can occur whenever the critical heat generation rate for a given reservoir temperature is exceeded. To provide an adequate safety margin against such an occurrence, thermionic systems must be operated at relatively high cesium pressures, even though this may cause some performance degradation. This paper consists of two parts. The first explains the above effect with reference to a single converter. The second part illustrates the effect of cesium reservoir temperatures on the dynamic behavior of an open-loop thermionic reactor following a small reactivity perturbation.

  20. Microbial accumulation of uranium, radium, and cesium

    International Nuclear Information System (INIS)

    Strandberg, G.W.; Shumate, S.E. II; Parrott, J.R. Jr.; North, S.E.

    1981-05-01

    Diverse microbial species varied considerably in their ability to accumulate uranium, cesium, and radium. Mechanistic differences in uranium uptake by Saccharomyces cerevisiae and Pseudomonas aeruginosa were indicated. S. serevisiae exhibited a slow (hours) surface accumulation of uranium which was subject to environmental factors, while P. aeruginosa accumulated uranium rapidly (minutes) as dense intracellular deposits and did not appear to be affected by environmental parameters. Metabolism was not required for uranium uptake by either organism. Cesium and radium were concentrated to a considerably lesser extent than uranium by the several species tested

  1. Bicarbonate Elution of Uranium from Amidoxime-Based Polymer Adsorbents for Sequestering Uranium from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Horng-Bin [Department of Chemistry, University of Idaho, Moscow, Idaho 83844 USA; Wai, Chien M. [Department of Chemistry, University of Idaho, Moscow, Idaho 83844 USA; Kuo, Li-Jung [Pacific Northwest National Laboratory, Marine Sciences Laboratory, Sequim, Washington 98382 USA; Gill, Gary [Pacific Northwest National Laboratory, Marine Sciences Laboratory, Sequim, Washington 98382 USA; Tian, Guoxin [Lawrence Berkeley National Laboratory, Berkeley, California 94720 USA; Rao, Linfeng [Lawrence Berkeley National Laboratory, Berkeley, California 94720 USA; Das, Sadananda [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 USA; Mayes, Richard T. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 USA; Janke, Christopher J. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 USA

    2017-05-02

    Uranium adsorbed on amidoxime-based polyethylene fibers in simulated seawater can be quantitatively eluted using 3 M KHCO3 at 40°C. Thermodynamic calculations are in agreement with the experimental observation that at high bicarbonate concentrations (3 M) uranyl ions bound to amidoxime molecules are converted to uranyl tris-carbonato complex in the aqueous solution. The elution process is basically the reverse reaction of the uranium adsorption process which occurs at a very low bicarbonate concentration (~10-3 M) in seawater. In real seawater experiments, the bicarbonate elution is followed by a NaOH treatment to remove natural organic matter adsorbed on the polymer adsorbent. Using the sequential bicarbonate and NaOH elution, the adsorbent is reusable after rinsing with deionized water and the recycled adsorbent shows no loss of uranium loading capacity based on real seawater experiments.

  2. Cesium and Strontium Separation Technologies Literature Review

    Energy Technology Data Exchange (ETDEWEB)

    T. A. Todd; T. A. Todd; J. D. Law; R. S. Herbst

    2004-03-01

    Integral to the Advanced Fuel Cycle Initiative (AFCI) Program’s proposed closed nuclear fuel cycle, the fission products cesium and strontium in the dissolved spent nuclear fuel stream are to be separated and managed separately. A comprehensive literature survey is presented to identify cesium and strontium separation technologies that have the highest potential and to focus research and development efforts on these technologies. Removal of these high-heat-emitting fission products reduces the radiation fields in subsequent fuel cycle reprocessing streams and provides a significant short-term (100 yr) heat source reduction in the repository. This, along with separation of actinides, may provide a substantial future improvement in the amount of fuel that could be stored in a geologic repository. The survey and review of the candidate cesium and strontium separation technologies are presented herein. Because the AFCI program intends to manage cesium and strontium together, technologies that simultaneously separate both elements are of the greatest interest, relative to technologies that separate only one of the two elements.

  3. Pharmacokinetics of gentamicin eluted from a regenerating bone graft substitute

    DEFF Research Database (Denmark)

    Stravinskas, M; Horstmann, P; Ferguson, J

    2016-01-01

    in combination with bone regeneration. Gentamicin release was measured in four setups: 1) in vitro elution in Ringer's solution; 2) local elution in patients treated for trochanteric hip fractures or uncemented hip revisions; 3) local elution in patients treated with a bone tumour resection; and 4) local elution...

  4. Distribution of radioactive cesium and stable cesium in cattle kept on a highly contaminated area of Fukushima nuclear accident.

    Science.gov (United States)

    Sato, Itaru; Okada, Keiji; Sasaki, Jun; Chida, Hiroyuki; Satoh, Hiroshi; Miura, Kiyoshi; Kikuchi, Kaoru; Otani, Kumiko; Sato, Shusuke

    2015-07-01

    Radioactivity inspection of slaughtered cattle is generally conducted using a portion of the neck muscle; however, there is limited information about the distribution of radioactive cesium in cattle. In this study, therefore, we measured not only radioactive cesium but also stable cesium in various tissues of 19 cattle that had been kept in the area highly contaminated by the Fukushima nuclear accident. Skeletal muscles showed approximately 1.5-3.0 times higher concentration of radioactive cesium than internal organs. Radioactive cesium concentration in the tenderloin and top round was about 1.2 times as high as that in the neck muscle. The kidney showed the highest concentration of radioactive cesium among internal organs, whereas the liver was lowest. Radioactive cesium concentration in the blood was about 8% of that in the neck muscle. Characteristics of stable cesium distribution were almost the same as those of radioactive cesium. Correlation coefficient between radioactive cesium and stable cesium in tissues of individual cattle was 0.981 ± 0.012. When a suspicious level near 100 Bq/kg is detected in the neck of slaughtered cattle, re-inspection should be conducted using a different region of muscle, for example top round, to prevent marketing of beef that violates the Food Sanitation Act. © 2014 Japanese Society of Animal Science.

  5. Ion exchange removal of cesium from Hanford tank waste supernates with SuperLigR 644 resin

    International Nuclear Information System (INIS)

    Hassan, N.M.; McCabe, D.J.; King, W.D.; Hamm, L.L.

    2002-01-01

    SuperLig R 644 ion exchange resin is currently being evaluated for cesium ( 137 Cs) removal from radioactive Hanford tank waste supernates as part of the River Protection Project. Testing was performed with actual Hanford tank wastes of widely different compositions using two identical ion exchange columns connected in series each containing approximately 5.5-6.5 ml of SuperLig R 644 resin. The ion exchange columns utilized the same resin material that was eluted between the column tests. This was done to demonstrate the performance of the SuperLig R 644 resin for cesium removal from waste samples of different compositions, determine the loading and elution profiles, and to validate design assumptions for full-scale column performances. Decontaminated product solutions generated at the same operating temperature and constant residence times (bed volumes per hour) exhibited the same chemical compositions as their feed samples. The compositions of eluate solutions were generally as expected with the exception of uranium and total organic carbon, which where concentrated by the resin. Development of a pretreatment method for the SuperLig R 644 resin has been critical to successful column operation with different waste solutions. (author)

  6. Comparison of zotarolimus-eluting and sirolimus-eluting coronary stents

    DEFF Research Database (Denmark)

    Maeng, Michael; Jensen, Lisette O; Kaltoft, Anne Kjer

    2012-01-01

    ABSTRACT: BACKGROUND: We evaluated the effectiveness and safety of a zotarolimus-eluting (ZES) versus a sirolimus-eluting (SES) coronary stent in a large cohort of patients treated with one of these stents in Western Denmark. METHODS: A total of 6,122 patients treated with ZES (n = 2,282) or SES ...

  7. Thermochemical evaluation and preparation of cesium uranates

    International Nuclear Information System (INIS)

    Takano, Masahide; Minato, Kazuo; Fukuda, Kousaku; Sato, Seichi; Ohashi, Hiroshi.

    1997-03-01

    Two kinds of cesium uranates, Cs 2 UO 4 and Cs 2 U 2 O 7 , which are predicted by thermochemical estimation to be formed in irradiated oxide fuels, were prepared from U 3 O 8 and Cs 2 CO 3 for measurements of the thermal expansions and thermal conductivities. In advance of the preparation, thermochemical calculations for the formation and decomposition of these cesium uranates were performed by Gibbs free energy minimizer. The preparation temperatures for Cs 2 UO 4 and Cs 2 U 2 O 7 were determined from the results of the thermochemical calculations. The prepared samples were analyzed by X-ray diffraction, which showed that the single phases of Cs 2 UO 4 and Cs 2 U 2 O 7 were formed. Thermogravimetry and differential thermal analysis were also performed on these samples, and the decomposition temperatures were evaluated. The experimental results were in good agreement with those of the thermochemical calculations. (author)

  8. Photon interactions in a cesium beam

    International Nuclear Information System (INIS)

    Nygaard, K.J.; Jones, J.D.; Hebner, R.E. Jr

    1974-01-01

    Photoionization of excited cesium atoms in the 6 2 P3/2 - state has been studied in a triple crossed-beam experiment. A thermal beam of cesium atoms was intersected by one photon beam of wavelength 8521A that served to excite the atoms and another photon beam with wavelengths below 5060A that served to ionize the excited atoms. The resulting ions were detected with a channel electron multiplier. All background effects were discriminated against by chopping the beam of exciting radiation and by analyzing the net count rate with digital synchronous techniques. The relative cross section for photoionization fo Cs(6 2 P3/2) has been measured from threshold (5060A) to 2500A. The results fall off faster than the theoretical calculations of Weisheit and Norcross

  9. Synthesis and properties of cesium metaarsenate vanadate

    Energy Technology Data Exchange (ETDEWEB)

    Golovkin, B.G.; Slepukhin, V.K.; Volkov, V.L.

    1988-12-01

    The aim of this study was to synthesize mixed cesium vanadatoarsenate and to determine its x-ray and luminescent characteristics. Cesium metavanadate and metaarsenate were prepared from chemically pure CsNO/sub 3/ and V/sub 2/O/sub 5/ and arsenic pentoxide. The compound Cs/sub 3/(AsO/sub 3/)(VO/sub 3/)/sub 2/ was obtained by sintering stoichiometric quantities of Cs/sub 3/AsO/sub 4/ and V/sub 2/O/sub 5/ and its thermal and optical properties were studied. Upon being subjected to photoexcitation Cs/sub 3/(AsO/sub 3/)(VO/sub 3/)/sub 2/ displays strong greenish-yellow luminescence with a brightness that is 66% of that of CsVO/sub 3/ luminescence.

  10. Progress toward Brazilian cesium fountain second generation

    Science.gov (United States)

    Bueno, Caio; Rodriguez Salas, Andrés; Torres Müller, Stella; Bagnato, Vanderlei Salvador; Varela Magalhães, Daniel

    2018-03-01

    The operation of a Cesium fountain primary frequency standard is strongly influenced by the characteristics of two important subsystems. The first is a stable frequency reference and the second is the frequency-transfer system. A stable standard frequency reference is key factor for experiments that require high accuracy and precision. The frequency stability of this reference has a significant impact on the procedures for evaluating certain systematic biases in frequency standards. This paper presents the second generation of the Brazilian Cesium Fountain (Br-CsF) through the opto-mechanical assembly and vacuum chamber to trap atoms. We used a squared section glass profile to build the region where the atoms are trapped and colled by magneto-optical technique. The opto-mechanical system was reduced to increase stability and robustness. This newest Atomic Fountain is essential to contribute with time and frequency development in metrology systems.

  11. Synthesis of double condensed cesium gallium phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Chudinova, N.N.; Grunze, I.; Guzeeva, L.S.; Avaliani, M.A.

    1987-09-01

    By crystallization from melts of polyphosphoric acids there are obtained double condensed phosphates of cesium and gallium of the following compositions: Cs/sub 2/GaH/sub 3/(P/sub 2/O/sub 7/)/sub 2/, CsGaHP/sub 3/O/sub 10/, Cs/sub 3/Ga/sub 3/P/sub 12/O/sub 36/. Their x-ray characteristics are given.

  12. Cesium migration experiments in different media

    International Nuclear Information System (INIS)

    Tello, C.C.O. de

    1992-01-01

    The environmental impact caused by the radioactive waste disposal depends on many factors, mainly on the release pathways of the radionuclides from the waste product to the environment. The migration of the radioelements through the different barriers, which compose the disposal system, is considered the main via for this release. This paper describes the experiments carried out to improve the cemented waste quality, as well to assess the cesium migration in different media. (author)

  13. Transfer studies of cesium-137 in marine trophic chain

    International Nuclear Information System (INIS)

    Marchese, S.R.M.; Cunha, I.I.L.

    1994-01-01

    The both concentration factor and elimination factor of cesium-137 by the food chain: Tetraselmis gracilis, Artemia salina e Abdefduf saxatilis, were determined in laboratory conditions. The results of laboratory experiments on the uptake, accumulation and elimination of cesium-137 by the species above mentioned are described. The concentration factor determination is important to the study of cesium-137 transfer through food-chain. (author). 5 refs, 3 tabs

  14. Cesium-137 retention in irops obtained from various soils

    International Nuclear Information System (INIS)

    Gulyakin, I.V.; Yudintseva, E.V.; Gorina, L.I.

    1974-01-01

    A non-station experiment has shown that the accumulation of cesium-137 in a plant yield depends on the type of soil. The highest contents of cesium-137 were found in the yield of plants from soddy-podzolic sandy loam soils, and the lowest- in those from leached chernozem. The accumulation of radiocesium in the yield of the basic produce strongly depended on the plant species. The amount of cesium-137 differed 5- to 7-fold in different crops

  15. Cesium-137 as a radiation source

    International Nuclear Information System (INIS)

    McMullen, W.H.; Sloan, D.P.

    1985-01-01

    The U.S. Department of Energy (DOE) Byproducts Utilization Program (BUP) seeks to develop and encourage widespread commercial use of defense byproducts that are produced by DOE. Cesium-l37 is one such byproduct that is radioactive and decays with emission of gamma rays. The beneficial use of this radiation to disinfect sewage sludge or disinfest food commodities is actively being pursued by the program. The radiation produced by cesium-l37(Cs-l37) is identical in form to that produced by cobalt-60(Co-60), an isotope that is widely used in commercial applications such as medical product sterilization. The choice of isotope to use depends on several factors ranging from inherent properties of the isotopes to availability and cost. The BUP, although centrally concerned with the beneficial use of Cs-l37, by investigating and assessing the feasibility of various uses hopes to define appropriate circumstances where cesium or cobalt might best be used to accomplish specific objectives. This paper discusses some of the factors that should be considered when evaluating potential uses for isotopic sources

  16. Quantum-degenerate cesium. Atoms and molecules

    International Nuclear Information System (INIS)

    Herbig, J.

    2005-04-01

    A Bose-Einstein condensate (BEC) of cesium atoms features the possibility to control the interatomic interaction. This outstanding property results from various couplings to molecular states, which show up in a rich spectrum of Feshbach resonances at easily accessible magnetic fields. In the frame of this thesis, we create a BEC of cesium and exploit its tunability for new experiments on Cs atoms and in the creation of Cs molecules. To produce the BEC we employ a sequence of two optical traps to realize good loading conditions as well as efficient evaporation. With this strategy we were able to create the first BEC of cesium. Optimization yields more than 100000 condensed atoms. We demonstrate the tunability of the mean-field interaction in the condensate by measuring the release energy as a function of the scattering lengths. By switching the scattering length to zero, we realize a non-expanding 'frozen condensate'. We use the BEC to create ultracold Cs 2 molecules by applying a magnetic field ramp over a Feshbach resonance. We separate atoms from molecules in a Stern-Gerlach type scheme. We observe ultra-low molecular expansion energies, consistent with the presence of a macroscopic molecular matter wave. Using a novel magnetic field ramping scheme we can greatly improve the achieved conversion efficiencies. In first experiments we transfer molecules to different internal molecular states using avoided level crossings. Finally, we demonstrate trapping of molecules in a CO 2 -laser trap, which offers a prospect for a trapped molecular BEC. (author)

  17. Lanthanide doped strontium-barium cesium halide scintillators

    Science.gov (United States)

    Bizarri, Gregory; Bourret-Courchesne, Edith; Derenzo, Stephen E.; Borade, Ramesh B.; Gundiah, Gautam; Yan, Zewu; Hanrahan, Stephen M.; Chaudhry, Anurag; Canning, Andrew

    2015-06-09

    The present invention provides for a composition comprising an inorganic scintillator comprising an optionally lanthanide-doped strontium-barium, optionally cesium, halide, useful for detecting nuclear material.

  18. Surface interactions of cesium and boric acid with stainless steel

    International Nuclear Information System (INIS)

    Grossman-Canfield, N.

    1995-08-01

    In this report, the effects of cesium hydroxide and boric acid on oxidized stainless steel surfaces at high temperatures and near one atmosphere of pressure are investigated. This is the first experimental investigation of this chemical system. The experimental investigations were performed using a mass spectrometer and a mass electrobalance. Surfaces from the different experiments were examined using a scanning electron microscope to identify the presence of deposited species, and electron spectroscopy for chemical analysis to identify the species deposited on the surface. A better understanding of the equilibrium thermodynamics, the kinetics of the steam-accelerated volatilizations, and the release kinetics are gained by these experiments. The release rate is characterized by bulk vaporization/gas-phase mass transfer data. The analysis couples vaporization, deposition, and desorption of the compounds formed by cesium hydroxide and boric acid under conditions similar to what is expected during certain nuclear reactor accidents. This study shows that cesium deposits on an oxidized stainless steel surface at temperatures between 1000 and 1200 Kelvin. Cesium also deposits on stainless steel surfaces coated with boric oxide in the same temperature ranges. The mechanism for cesium deposition onto the oxide layer was found to involve the chemical reaction between cesium and chromate. Some revaporization in the cesium hydroxide-boric acid system was observed. It has been found that under the conditions given, boric acid will react with cesium hydroxide to form cesium metaborate. A model is proposed for this chemical reaction

  19. Softening and elution of monomers in ethanol

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Asmussen, Erik; Munksgaard, E Christian

    2009-01-01

    The purpose of this study was to investigate the effect of light-curing protocol on softening and elution of monomers in ethanol as measured on a model polymer. It was a further aim to correlate the measured values with previously reported data on degree of conversion and glass transition...

  20. Separation of cesium by ion exchange columns

    International Nuclear Information System (INIS)

    Bonini, Alberto; Falcon, Marcelo F.; Devida, Claudio A.; Tadey, D.; Vaccaro, Jorge O.; Maset, Elvira

    2003-01-01

    Crystalline silico titanate (CST) has been tested as a selective inorganic ion exchanger to separate Cs 137 from the residual fission product s solution of the Mo 99 plant. The tests are described in detail and show decontamination factors higher than 6000 and a good elution yield

  1. Strontium-90 and cesium-137 in powdered milk

    International Nuclear Information System (INIS)

    1977-01-01

    Japan Chemical Analysis Center has analysed the strontium-90 and cesium-137 content in powdered milk. The samples were purchased on the open market in Tokyo from the powdered milk producers. The analysis of Strontium-90 and Cesium-137 content was carried out using the method recommended by Science and Technology Agency. (author)

  2. Ion exchange pretreatment of alkaline radwaste for cesium removal

    International Nuclear Information System (INIS)

    Bibler, J.P.

    1994-08-01

    A cation exchange resin has been tested for its ability to remove the Cs ion from simulants of highly alkaline liquid nuclear wastes found at the Savannah River Site, Oak Ridge, and Hanford. The resin is a condensation polymer of the K salt of resorcinol and formaldehyde. It removes milli- and micromolar amounts of Cs + from solutions that contain as high as 11 molar Na + . Small column tests indicate that approximately 200 column volumes of SRS simulant and 205 column volumes of OR Tank 25 supernatant simulant can be processed before the resin requires regeneration. For these two wastes, a carousel arrangement of two columns in series and a third in reserve can be used effectively in a process. Hanford 101-AW simulant generates a less sharp breakthrough profile with this resin, though an operation using a maximum of three columns in series with another column off-line for regeneration would be effective if the resin beds are allowed to reach about 90% breakthrough before taking them out of service. Parameters that effect the performance of the resin with a particular feed solution are the concentrations of the two primary ions of interest, Cs + and Na + , as well as the concentrations of K + and OH - . A further ramification of the hydroxide ion concentration is its role in assisting oxidation of the resin, thereby destroying its usefulness in cesium removal. Although the performance of the resin is unaffected at doses of 1 E+8 rad ionizing radiation, it shows noticeable degradation after storage for 100 hours in alkaline solutions, generating quinone and ketone groups, as determined from C-13 NMR and by an increase in total organic C content of the contacting solution. Gases detected from the radiolysis of the resin/simulant mixture are CO 2 from the resin, N 2 O from nitrate in the simulant, and H 2 possibly from resin and simulant. Oxygen depletion in the mixture results from radiolysis and chemical degradation

  3. Magnetic circular Dichroism and Faraday rotation of cesium-argon excimers and cesium dimers

    International Nuclear Information System (INIS)

    Islam, M.A.

    1981-01-01

    Magnetic Circular Dichroism (MCD) and Faraday Rotation (FR) of excimer absorption bands in gases are measured to obtain the first direct information about the angular momentum quantum numbers and the angular momentum coupling schemes of excimer molecules. So far, there has been no experimental method to obtain information about the axial angular momentum and the angular momentum coupling schemes of excimer molecules. In this experiment, the MCD and the FR of cesium-argon excimer and cesium dimer absorption bands between 5000 A and 10,000 A are measured for the range of temperature from 116 0 to 355 0 C. Of particular interest is the blue wing of D 2 line in cesium which has been the subject of vigorous investigation. The measured MCD data at the blue wing of D 2 line clearly shows that the assignment of 2 μ/sub 1/2/ to this excited state assuming Hund's case (b) is a poor approximation. By a simple inspection of the MCD data, it is found that the coupling scheme is more nearly Hund's case (c) than Hynd's case (b). Several other new and interesting results are obtained. The blue wing associated with 5D transition in atomic cesium is devoid of MCD and exhibits strong MCD in the red wings. Thus, the assignment of 2 μ/sub 1/2/ and 2 π to the blue and red wings, respectively, assuming Hund's case (a) and (b), is a very good approximation. Again the yellow-green band associated with 7s-6s transition in atomic cesium shows no MCD. It is therefore also a good approximation to assign 2 μ/sub 1/2/ to the upper state assuming Hund's case (b). Much more information can be obtained by a detailed analysis of the MCD data

  4. A combined cesium-strontium extraction/recovery process

    International Nuclear Information System (INIS)

    Horwitz, E.P.; Dietz, M.L.; Jensen, M.P.

    1996-01-01

    A new solvent extraction process for the simultaneous extraction of cesium and strontium from acidic nitrate media is described. This process uses a solvent formulation comprised of 0.05 M di-t-butylcyclohexano-18-crown-6 (DtBuCH18C6), 0.1 M Crown 100' (a proprietary, cesium-selective derivative of dibenzo-18-crown-6), 1.2 M tributyl phosphate (TBP), and 5% (v/v) lauryl nitrile in an isoparaffinic hydrocarbon diluent. Distribution ratios for cesium and strontium from 4 M nitric acid are 4.13 and 3.46, respectively. A benchtop batch countercurrent extraction experiment indicates that >98% of the cesium and strontium initially present in the feed solution can be removed in only four extraction stages. Through proper choice of extraction and strip conditions, extracted cesium and strontium can be recovered either together or individually

  5. Radiation safety for incineration of radioactive waste contaminated by cesium

    International Nuclear Information System (INIS)

    Veryuzhs'kij, Yu.V.; Gryin'ko, O.M.; Tokarevs'kij, V.V.

    2016-01-01

    Problems in the treatment of radioactive waste contaminated by cesium nuclides are considered in the paper. Chornobyl experience in the management of contaminated soil and contaminated forests is analyzed in relation to the accident at Fukushima-1. The minimization of release of cesium aerosols into atmosphere is very important. Radiation influence of inhaling atmosphere aerosols polluted by cesium has damage effect for humans. The research focuses on the treatment of forests contaminated by big volumes of cesium. One of the most important technologies is a pyro-gasification incineration with chemical reactions of cesium paying attention to gas purification problems. Requirements for process, physical and chemical properties of treatment of radioactive waste based on the dry pyro-gasification incineration facilities are considered in the paper together with the discussion of details related to incineration facilities. General similarities and discrepancies in the environmental pollution caused by the accidents at Chornobyl NPP and Fukushima-1 NPP in Japan are analyzed

  6. Cesium-137 in grass from Chernobyl fallout

    International Nuclear Information System (INIS)

    Papastefanou, C.; Manolopoulou, M.; Stoulos, S.; Ioannidou, A.; Gerasopoulos, E.

    2005-01-01

    Grass ecosystem was monitored for 137 Cs, a relatively long-lived radionuclide, for about 16 years since the Chernobyl reactor accident occurred on April 26, 1986. Cesium-137 in grass gramineae or poaceae the species, ranged from 122.9 Bq kg -1 (September 4, 1986) to 5.8 mBq kg -1 (October 16, 2001) that is a range of five orders of magnitude. It was observed that there was a trend of decreasing 137 Cs with time reflecting a removal half-time of 40 months (3 1/3 years), which is the ecological half-life, T ec of 137 Cs in grassland

  7. Test for radioactive cesium in water - 1973

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Radioactive cesium in water in concentrations >1 μCi/1 is determined by gamma counting of a Cs-tetraphenylborate solution in amyl acetate. The method is limited to Cs isotopes of mass 134, 136, 137, and 138. Fission product extraction is prevented by the presence of EDTA in the solution to be extracted. Macro amounts of NH 4 + , Rb + , K + , Ag + , and Na + interfere with the determination. After the extraction and measurement of the gamma spectrum, the spectrum is resolved into its components by graphical or algebraic methods, and the count rate due to each isotope is obtained. For a single operator, precision of the method is better than +-1%

  8. Adsorption of cesium on cement mortar from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Volchek, Konstantin, E-mail: konstantin.volchek@ec.gc.ca [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, Canada K1A 0H3 (Canada); Miah, Muhammed Yusuf [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, Canada K1A 0H3 (Canada); Department of Applied Chemistry and Chemical Technology, Noakhali Science and Technology University (Bangladesh); Kuang, Wenxing; DeMaleki, Zack [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, Canada K1A 0H3 (Canada); Tezel, F. Handan [Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis-Pasteur, Ottawa, Ontario, Canada K1N 6N5 (Canada)

    2011-10-30

    Highlights: {yields} The adsorption of cesium on cement mortar was investigated in a range of temperatures and cesium concentrations. {yields} The pseudo-second order kinetic model produced a good fit with the experimental kinetic data. {yields} Equilibrium test results correlated well with the Freundlich isotherm adsorption model. {yields} The interaction between cesium ions and cement mortar was dominated by chemical adsorption. - Abstract: The adsorption of cesium on cement mortar from aqueous solutions was studied in series of bench-scale tests. The effects of cesium concentration, temperature and contact time on process kinetics and equilibrium were evaluated. Experiments were carried out in a range of initial cesium concentrations from 0.0103 to 10.88 mg L{sup -1} and temperatures from 278 to 313 K using coupons of cement mortar immersed in the solutions. Non-radioactive cesium chloride was used as a surrogate of the radioactive {sup 137}Cs. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectroscopy. Depending on the initial cesium concentration, its equilibrium concentration in solution ranged from 0.0069 to 8.837 mg L{sup -1} while the respective surface concentration on coupons varied from 0.0395 to 22.34 {mu}g cm{sup -2}. Equilibrium test results correlated well with the Freundlich isotherm model for the entire test duration. Test results revealed that an increase in temperature resulted in an increase in adsorption rate and a decrease in equilibrium cesium surface concentration. Among several kinetic models considered, the pseudo-second order reaction model was found to be the best to describe the kinetic test results in the studied range of concentrations. The adsorption activation energy determined from Arrhenius equation was found to be approximately 55.9 kJ mol{sup -1} suggesting that chemisorption was the prevalent mechanism of interaction between cesium ions and cement mortar.

  9. Measurements of cesium in Arctic beluga and caribou before and after the Fukushima accident of 2011.

    Science.gov (United States)

    Stocki, T J; Gamberg, M; Loseto, L; Pellerin, E; Bergman, L; Mercier, J-F; Genovesi, L; Cooke, M; Todd, B; Sandles, D; Whyte, J; Wang, X

    2016-10-01

    Concern from northern communities following the Fukushima Daiichi nuclear accident of March 2011 has prompted a reassessment of the safety of their traditional foods with respect to radioactivity levels. To this end, a study was conducted to measure the levels of radionuclides in Arctic caribou (Rangifer tarandus) and beluga (Delphinapterus leucas). The main radionuclide of concern is cesium-137, which is easily transferred through the lichen-caribou food chain. Previous studies have been conducted on the cesium-137 levels in Canadian caribou herds from 1958 to 2000, allowing researchers to determine the amount of cesium-137 in caribou specifically attributable to atmospheric weapons testing and the Chernobyl nuclear accident in 1986. In this study, samples of lichens, mushrooms, caribou, beluga and beluga prey collected before and after the Fukushima accident were analyzed for radioactivity levels. Samples were processed and measured using gamma ray spectroscopy to identify the radionuclides present and determine the radioactivity concentration. Both calibration standards and Monte Carlo simulations were used to determine the efficiency of the detectors for the samples, taking into account differences in individual sample sizes as well as matrices. In particular, a careful analysis of the atomic composition of lichens and mushrooms was performed to ensure the efficiencies for these sample types were correct. A comparison of the concentrations from before and after the accident indicated that there was no increase in radioactivity as a result of the atmospheric plume from the Fukushima accident. Some cesium-137, likely attributable to fallout from atmospheric weapons testing of the 1950s and 1960s (since there was no cesium-134 measured in the samples), was measured in the post Fukushima caribou and beluga whale samples; however, this amount was determined to be insignificant for any radiological concern (9.1 ± 1.8 and 0.63 ± 0.23 Bq kg -1  ww respectively

  10. Elution of Monomers from Provisional Composite Materials

    Directory of Open Access Journals (Sweden)

    Simon Daniel Schulz

    2015-01-01

    Full Text Available The aim of this study was to evaluate the elution of substances from different materials used for the manufacturing of temporary indirect restorations, after storage in saliva and ethanol 75%. 10 samples of three chemically cured materials (Protemp 3 Garant, Systemp.c&b, and Trim and one light-cured material (Clip F were stored in saliva and ethanol 75% for 24 h, 7, and days 28 days. From the storage media at each time period, samples were prepared and analysed by LC-MS/MS, in order to access the elution of monomers. The results differed among the materials (P ≤ 0.05. No monomers were detected in the samples of Protemp 3 Garant and Clip F. Substances were detected only in ethanol samples of Systemp.c&b and Trim. The amount of BisGMA, TEGDMA, and UDMA 2 released from Systemp.c&b was higher compared to Trim. Storage time affected the release of substances (P ≤ 0.05. The highest release was observed within the first 24 h. It can be concluded that provisional resin composite materials do not show high release of monomers and this release is material dependent. However, the detection of additional peaks during the analysis, suggesting the formation of by-products of the eluted substances, may not be in favour of these materials with respect to their toxicity.

  11. Engineered Materials for Cesium and Strontium Storage. Final Technical Report

    International Nuclear Information System (INIS)

    McDeavitt, Sean M.

    2010-01-01

    Closing the nuclear fuel cycle requires reprocessing spent fuel to recover the long-lived components that still have useful energy content while immobilizing the remnant waste fission products in stable forms. At the genesis of this project, next generation spent fuel reprocessing methods were being developed as part of the U.S. Department of Energy's Advanced Fuel Cycle Initiative. One of these processes was focused on solvent extraction schemes to isolate cesium (Cs) and strontium (Sr) from spent nuclear fuel. Isolating these isotopes for short-term decay storage eases the design requirements for long-term repository disposal; a significant amount of the radiation and decay heat in fission product waste comes from Cs-137 and Sr-90. For the purposes of this project, the Fission Product Extraction (FPEX) process is being considered to be the baseline extraction method. The objective of this project was to evaluate the nature and behavior of candidate materials for cesium and strontium immobilization; this will include assessments with minor additions of yttrium, barium, and rubidium in these materials. More specifically, the proposed research achieved the following objectives (as stated in the original proposal): (1) Synthesize simulated storage ceramics for Cs and Sr using an existing labscale steam reformer at Purdue University. The simulated storage materials will include aluminosilicates, zirconates and other stable ceramics with the potential for high Cs and Sr loading. (2) Characterize the immobilization performance, phase structure, thermal properties and stability of the simulated storage ceramics. The ceramic products will be stable oxide powders and will be characterized to quantify their leach resistance, phase structure, and thermophysical properties. The research progressed in two stages. First, a steam reforming process was used to generate candidate Cs/Sr storage materials for characterization. This portion of the research was carried out at Purdue

  12. Engineered Materials for Cesium and Strontium Storage Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Sean M. McDeavitt

    2010-04-14

    Closing the nuclear fuel cycle requires reprocessing spent fuel to recover the long-lived components that still have useful energy content while immobilizing the remnant waste fission products in stable forms. At the genesis of this project, next generation spent fuel reprocessing methods were being developed as part of the U.S. Department of Energy's Advanced Fuel Cycle Initiative. One of these processes was focused on solvent extraction schemes to isolate cesium (Cs) and strontium (Sr) from spent nuclear fuel. Isolating these isotopes for short-term decay storage eases the design requirements for long-term repository disposal; a significant amount of the radiation and decay heat in fission product waste comes from Cs-137 and Sr-90. For the purposes of this project, the Fission Product Extraction (FPEX) process is being considered to be the baseline extraction method. The objective of this project was to evaluate the nature and behavior of candidate materials for cesium and strontium immobilization; this will include assessments with minor additions of yttrium, barium, and rubidium in these materials. More specifically, the proposed research achieved the following objectives (as stated in the original proposal): (1) Synthesize simulated storage ceramics for Cs and Sr using an existing labscale steam reformer at Purdue University. The simulated storage materials will include aluminosilicates, zirconates and other stable ceramics with the potential for high Cs and Sr loading. (2) Characterize the immobilization performance, phase structure, thermal properties and stability of the simulated storage ceramics. The ceramic products will be stable oxide powders and will be characterized to quantify their leach resistance, phase structure, and thermophysical properties. The research progressed in two stages. First, a steam reforming process was used to generate candidate Cs/Sr storage materials for characterization. This portion of the research was carried out at

  13. Thermochemical evaluation and preparation of cesium uranates

    Energy Technology Data Exchange (ETDEWEB)

    Takano, Masahide; Minato, Kazuo; Fukuda, Kousaku [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Sato, Seichi; Ohashi, Hiroshi

    1997-03-01

    Two kinds of cesium uranates, Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub 7}, which are predicted by thermochemical estimation to be formed in irradiated oxide fuels, were prepared from U{sub 3}O{sub 8} and Cs{sub 2}CO{sub 3} for measurements of the thermal expansions and thermal conductivities. In advance of the preparation, thermochemical calculations for the formation and decomposition of these cesium uranates were performed by Gibbs free energy minimizer. The preparation temperatures for Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub 7} were determined from the results of the thermochemical calculations. The prepared samples were analyzed by X-ray diffraction, which showed that the single phases of Cs{sub 2}UO{sub 4} and Cs{sub 2}U{sub 2}O{sub 7} were formed. Thermogravimetry and differential thermal analysis were also performed on these samples, and the decomposition temperatures were evaluated. The experimental results were in good agreement with those of the thermochemical calculations. (author)

  14. Integral cesium reservoir: Design and transient operation

    Science.gov (United States)

    Smith, Joe N., Jr.; Horner, M. Harlan; Begg, Lester L.; Wrobleski, William J.

    An electrically heated thermionic converter has been designed built and successfully tested in air. One of the unique features of this converter was an integral cesium reservoir thermally coupled to the emitter. The reservoir consisted of fifteen cesiated graphite pins located in pockets situated in the emitter lead with thermal coupling to the emitter, collector and the emitter terminal; there were no auxiliary electric heaters on the reservoir. Test results are described for conditions in which the input thermal power to the converter was ramped up and down between 50% and 100% of full power in times as short as 50 sec, with data acquisition occurring every 12 sec. During the ramps the emitter and collector temperature profiles. the reservoir temperature and the electric output into a fixed load resistor are reported. The converter responded promptly to the power ramps without excessive overshoot and with no tendency to develop instabilities. This is the rust demonstration of the performance of a cesium-graphite integral reservoir in a fast transient.

  15. Intense non-relativistic cesium ion beam

    International Nuclear Information System (INIS)

    Lampel, M.C.

    1984-02-01

    The Heavy Ion Fusion group at Lawrence Berkeley Laboratory has constructed the One Ampere Cesium Injector as a proof of principle source to supply an induction linac with a high charge density and high brightness ion beam. This is studied here. An electron beam probe was developed as the major diagnostic tool for characterizing ion beam space charge. Electron beam probe data inversion is accomplished with the EBEAM code and a parametrically adjusted model radial charge distribution. The longitudinal charge distribution was not derived, although it is possible to do so. The radial charge distribution that is derived reveals an unexpected halo of trapped electrons surrounding the ion beam. A charge fluid theory of the effect of finite electron temperature on the focusing of neutralized ion beams (Nucl. Fus. 21, 529 (1981)) is applied to the problem of the Cesium beam final focus at the end of the injector. It is shown that the theory's predictions and assumptions are consistent with the experimental data, and that it accounts for the observed ion beam radius of approx. 5 cm, and the electron halo, including the determination of an electron Debye length of approx. 10 cm

  16. Microbial uptake of uranium, cesium, and radium

    Energy Technology Data Exchange (ETDEWEB)

    Strandberg, G.W.; Shumate, S.E. II; Parrott, J.R. Jr.; McWhirter, D.A.

    1980-01-01

    The ability of diverse microbial species to concentrate uranium, cesium, and radium was examined. Saccharomyces cerevisiae, Pseudomonas aeruginosa, and a mixed culture of denitrifying bacteria accumulated uranium to 10 to 15% of the dry cell weight. Only a fraction of the cells in a given population had visible uranium deposits in electron micrographs. While metabolism was not required for uranium uptake, mechanistic differences in the metal uptake process were indicated. Uranium accumulated slowly (hours) on the surface of S. cerevisiae and was subject to environmental factors (i.e., temperature, pH, interfering cations and anions). In contrast, P. aeruginosa and the mixed culture of denitrifying bacteria accumulated uranium rapidly (minutes) as dense, apparently random, intracellular deposits. This very rapid accumulation has prevented us from determining whether the uptake rate during the transient between the initial and equilibrium distribution of uranium is affected by environmental conditions. However, the final equilibrium distributions are not affected by those conditions which affect uptake by S. cerevisiae. Cesium and radium were concentrated to a considerably lesser extent than uranium by the several microbial species tested. The potential utility of microorganisms for the removal and concentration of these metals from nuclear processing wastes and several bioreactor designs for contacting microorganisms with contaminated waste streams will be discussed.

  17. Microbial uptake of uranium, cesium, and radium

    International Nuclear Information System (INIS)

    Strandberg, G.W.; Shumate, S.E. II; Parrott, J.R. Jr.; McWhirter, D.A.

    1980-01-01

    The ability of diverse microbial species to concentrate uranium, cesium, and radium was examined. Saccharomyces cerevisiae, Pseudomonas aeruginosa, and a mixed culture of denitrifying bacteria accumulated uranium to 10 to 15% of the dry cell weight. Only a fraction of the cells in a given population had visible uranium deposits in electron micrographs. While metabolism was not required for uranium uptake, mechanistic differences in the metal uptake process were indicated. Uranium accumulated slowly (hours) on the surface of S. cerevisiae and was subject to environmental factors (i.e., temperature, pH, interfering cations and anions). In contrast, P. aeruginosa and the mixed culture of denitrifying bacteria accumulated uranium rapidly (minutes) as dense, apparently random, intracellular deposits. This very rapid accumulation has prevented us from determining whether the uptake rate during the transient between the initial and equilibrium distribution of uranium is affected by environmental conditions. However, the final equilibrium distributions are not affected by those conditions which affect uptake by S. cerevisiae. Cesium and radium were concentrated to a considerably lesser extent than uranium by the several microbial species tested. The potential utility of microorganisms for the removal and concentration of these metals from nuclear processing wastes and several bioreactor designs for contacting microorganisms with contaminated waste streams will be discussed

  18. WESF cesium capsule behavior at high temperature or during thermal cycling

    International Nuclear Information System (INIS)

    Tingey, G.L.; Gray, W.J.; Shippell, R.J.; Katayama, Y.B.

    1985-06-01

    Double-walled stainless steel (SS) capsules prepared for storage of radioactive 137 Cs from defense waste are now being considered for use as sources for commercial irradiation. Cesium was recovered at B-plant from the high-level radioactive waste generated during processing of defense nuclear fuel. It was then purified, converted to the chloride form, and encapsulated at the Hanford Waste Encapsulation and Storage Facility (WESF). The molten cesium chloride salt was encapsulated by pouring it into the inner of two concentric SS cylinders. Each cylinder was fitted with a SS end cap that was welded in place by inert gas-tungsten arc welding. The capsule configuration and dimensions are shown in Figure 1. In a recent review of the safety of these capsules, Tingey, Wheelwright, and Lytle (1984) indicated that experimental studies were continuing to produce long-term corrosion data, to reaffirm capsule integrity during a 90-min fire where capsule temperatures reached 800 0 C, to monitor mechanical properties as a function of time, and to assess the effects of thermal cycling due to periodic transfer of the capsules from a water storage pool to the air environment of an irradiator facility. This report covers results from tests that simulated the effects of the 90-min fire and from thermal cycling actual WESF cesium capsules for 3845 cycles over a period of six months. 11 refs., 39 figs., 9 tabs

  19. Optically pumped semiconductor lasers: Conception and characterization of a single mode source for Cesium atoms manipulation

    International Nuclear Information System (INIS)

    Cocquelin, B.

    2009-02-01

    Lasers currently used in atomic clocks or inertial sensors are suffering from a lack of power, narrow linewidth or compactness for future spatial missions. Optically pumped semiconductor lasers, which combine the approach of classical solid state lasers and the engineering of semiconductor laser, are considered here as a candidate to a metrological laser source dedicated to the manipulation of Cesium atoms in these instruments. These lasers have demonstrated high power laser emission in a circular single transverse mode, as well as single longitudinal mode emission, favoured by the semiconductor structure and the external cavity design. We study the definition and the characterization of a proper semiconductor structure for the cooling and the detection of Cesium atoms at 852 nm. A compact and robust prototype tunable on the Cesium D2 hyperfine structure is built. The laser frequency is locked to an atomic transition thanks to a saturated absorption setup. The emission spectral properties are investigated, with a particular attention to the laser frequency noise and the laser linewidth. Finally, we describe and model the thermal properties of the semiconductor structure, which enables the simulation of the laser power characteristic. The experimental parameters are optimised to obtain the maximum output power with our structure. Thanks to our analysis, we propose several ways to overcome these limitations, by reducing the structure heating. (authors)

  20. A novel role for methyl cysteinate, a cysteine derivative, in cesium accumulation in Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Adams, Eri; Miyazaki, Takae; Hayaishi-Satoh, Aya

    2017-01-01

    Phytoaccumulation is a technique to extract metals from soil utilising ability of plants. Cesium is a valuable metal while radioactive isotopes of cesium can be hazardous. In order to establish a more efficient phytoaccumulation system, small molecules which promote plants to accumulate cesium were...... investigated. Through chemical library screening, 14 chemicals were isolated as 'cesium accumulators' in Arabidopsis thaliana. Of those, methyl cysteinate, a derivative of cysteine, was found to function within the plant to accumulate externally supplemented cesium. Moreover, metabolite profiling demonstrated...

  1. Polyethylene glycol improves elution properties of polymethyl methacrylate bone cements.

    Science.gov (United States)

    Handal, John A; Tiedeken, Nathan C; Gershkovich, Grigory E; Kushner, Jeffrey A; Dratch, Benjamin; Samuel, Solomon P

    2015-03-01

    Bone cements are used as adjuncts to fracture fixation methods and can also function as a local drug delivery system. The ability to elute drugs makes bone cement a promising and powerful chemotherapy treatment modality for osseous tumors. However, because of poor elution rates, the clinical application of this drug delivery mode remains challenging. Soluble fillers, such as sugars, salts, or biocompatible polymers, offer a solution to improve elution rates. This study quantified the effect of polyethylene glycol (PEG) on the elution properties of three commercially available bone cements. Two grams of Vertebroplastic, Palacos, and Confidence bone cement powder containing three concentrations (0%, 20%, or 50%) of PEG filler were hand mixed with 10 mg of methotrexate. This powder mixture was then polymerized with 1.0 mL of the cement specific liquid monomer. The cylindrical elution samples were placed in saline solution and methotrexate elution was recorded for 720 h. The cumulative and daily elution rate increased as the concentration of PEG increased for each bone cement. However, the percent of increase depended on the bone cement used. Cumulative methotrexate elution increased by 40%-54% in case of the highest PEG filler concentration when compared with controls. PEG soluble filler offers a promising method for improving methotrexate drug elution in bone cement. Future studies need to optimize the PEG and bone cement ratio that produces the greatest drug elution profile without sacrificing the biomechanical properties of bone cement. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Seaweed against strontium and preussian blue against cesium

    Directory of Open Access Journals (Sweden)

    G Michanek

    1988-06-01

    Full Text Available The fact that alginates bind strontium and cyanates bind cesium and are capable of removing these elements from living organisms is scientifically verified. Zeolites offer another possibility for exchange of these ions. Practical research should be initiated to find the right doses and procedure to decrease the body burden of radioactive isotopes in reindeer.Alger mot strontium och berlinerblått mot cesium.Abstract in Swedish / Sammanfattning: Mitt budskap år kort: Alger binder strontium, Berlinerblått binder cesium, Sätt fart på forskning och forsök!

  3. Caustic-Side Solvent Extraction: Anti-Caking Surfactants Found to be Cause of Apparent Effect of High Nitrite Concentration on Cesium Stripping

    Energy Technology Data Exchange (ETDEWEB)

    Delmau, L.H.

    2002-06-13

    Experiments conducted in FY01 previously indicated a potential cesium stripping problem in the CSSX process due to the presence of nitrite in the waste simulant. The stripping issue seemed all the more important as the nitrite concentration increased. Experiments presented in this work have demonstrated that the true reason for the cesium stripping problem was in fact the presence of an anti-caking agent in the,sodium nitrite. used for the preparation of the simulants. The anti-caking agent is actually a mixture of well-known surfactants, sodium mono- and di-methyl naphthalene sulfonate that can partition into the organic-phase on extraction, then retain cesium upon stripping. The effect was demonstrated by adding known amounts of the anti-caking agent to clean systems. Data suggest that rejuvenation of the solvent can be obtained by a caustic wash following the stripping stage.

  4. Technical Approach for the Development of a Near Tank Cesium Removal Process

    International Nuclear Information System (INIS)

    Sams, T.L.; Miller, Ch.E.; Kurath, D.E.; Blanchard, D.L.

    2009-01-01

    Parsons has been selected for development of two Advanced Remediation Technology (ART) projects. One of these projects is the Near Tank Cesium Removal (NTCR) project. The NTCR system uses the same basic ion exchange approach for Cs removal that has been used for decades in the nuclear industry. The essential difference in this approach is the development of a modular, mobile design concept based on a simplified process employing an advanced resin media and the use of cool nitric acid for elution and heated nitric acid for resin digestion. Under these conditions, the NTCR process shows significant improvements over the baseline ion exchange technology. These improvements will allow DOE to deploy a NTCR, free up tank space and accelerate closure of SSTs prior to Waste Treatment Plant Pretreatment Facility startup (WTP PTF). Current estimates indicate that the Hanford tank farm system will run out of available storage space prior to startup of the WTP PTF currently scheduled for 2019. The lack of tank space will constrain the near-term goal of retrieving waste from single-shell tanks prior to full operation of the WTP. A deployment of an NTCR system will allow LAW processing to begin as soon as supplemental treatment (e.g. Bulk Vitrification) or the WTP LAW Vitrification Facility becomes available. The NTCR system is a self contained modular, transportable system that requires only limited process chemicals and separates the HLW into two process streams. Once the cesium is removed, the low activity waste stream can be vitrified. The high activity stream would be stored in the DST system until vitrified by the WTP High Level Waste (HLW) Facility. This technology can be sized to feed the WTP LAW melters at the nominal operating capacity (30 MT glass per day. Alternatively, it could be sized to feed a supplemental treatment system such the Bulk Vitrification process. The NTCR system is based on an elutable ion exchange system using the Spherical Resorcinol Formaldehyde

  5. Cesium and strontium in Black Sea macroalgae.

    Science.gov (United States)

    Nonova, Tzvetana; Tosheva, Zornitza

    2014-03-01

    The trace level of metals and particularly radioactive ones should be monitored to evaluate the transfer along the trophic chain, assess the risk for biota and can be used for global changes assessment. Plants respond rapidly to all changes in the ecosystem conditions and are widely used as indicators and predictors for changes in hydrology and geology. In this work we represent our successful development and applications of a methodology for monitoring of stable and radioactive strontium and cesium in marine biota (Black Sea algae's). In case of radioactive release they are of high interest. We use ED-XRF, gamma spectrometers and LSC instrumentation and only 0.25 g sample. Obtained results are compared with those of other authors in same regions. The novelty is the connection between the radioactive isotopes and their stable elements in algae in time and space scale. All our samples were collected from Bulgarian Black Sea coast. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Investigations on cesium uranates and related compounds

    International Nuclear Information System (INIS)

    Egmond, A.B. van

    1976-01-01

    Crystal structures of cesium uranate are determined mainly by X-ray diffraction techniques. From phase studies it is concluded that of the Cs-U-O system, Cs 2 U 4 O 12 will play a prominent role in fuel elements of fast reactors due to fission product-fuel reactions causing swelling of the fuel and fuel-element failure. Crystal structures and lattice parameters are determined from Cs 2 U 4 O 12 , Cs 2 U 4 O 13 , Cs 2 U 5 O 16 , Cs 4 U 5 O 17 , Cs 2 U 7 O 22 , Cs 2 U 15 O 46 , Cs 2 UO 4 and Cs 2 U 2 O 7 . Finally some crystal structures of potassium and rubidium uranates are measured and a comparison of all available data on alkali uranates is made

  7. Biosorption of uranium, radium, and cesium

    International Nuclear Information System (INIS)

    Strandberg, G.W.

    1982-01-01

    Some fundamental aspects of the biosorption of metals by microbial cells were investigated. These studies were carried out in conjunction with efforts to develop a process to utilize microbial cells as biosorbents for the removal of radionuclides from waste streams generated by the nuclear fuel cycle. It was felt that an understanding of the mechanism(s) of metal uptake would potentially enable the enhancement of the metal uptake phenomenon through environmental or genetic manipulation of the microorganisms. Also presented are the results of a preliminary investigation of the applicability of microorganisms for the removal of 137 cesium and 226 radium from existing waste solutions. The studies were directed primarily at a characterization of uranium uptake by the yeast, Saccharomyces cerevisiae, and the bacterium, Pseudomonas aeruginosa

  8. Social aspects concerning the cesium-137 accident

    International Nuclear Information System (INIS)

    Chaves, Elza Guedes

    1997-01-01

    The present work aims to understand how social representations constructed upon nuclear energy have influenced on molding and orienting public's behavior in the presence of the accident that occurred in Goiania with the capsule of Cesium-137. As a starting point, it is accepted here that panic caused by that accident could be properly understood only if dimension of subjectivity is taken into consideration. This perspective is required whenever events that put human life and environment in risk happen. Facing the accident, people internalized radioactivity, an unknown element, as certainty of cancer and death despite the fact that cancer and death could only outcome in case there had been excessive exposure to radioactivity. (author)

  9. Bentonite-Clay Waste Form for the Immobilization of Cesium and Strontium from Fuel Processing Waste Streams

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Michael D. [Argonne National Lab. (ANL), Argonne, IL (United States); Mertz, Carol J. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    The physical properties of a surrogate waste form containing cesium, strontium, rubidium, and barium sintered into bentonite clay were evaluated for several simulant feed streams: chlorinated cobalt dicarbollide/polyethylene glycol (CCD-PEG) strip solution, nitrate salt, and chloride salt feeds. We sintered bentonite clay samples with a loading of 30 mass% of cesium, strontium, rubidium, and barium to a density of approximately 3 g/cm3. Sintering temperatures of up to 1000°C did not result in volatility of cesium. Instead, there was an increase in crystallinity of the waste form upon sintering to 1000ºC for chloride- and nitrate-salt loaded clays. The nitrate salt feed produced various cesium pollucite phases, while the chloride salt feed did not produce these familiar phases. In fact, many of the x-ray diffraction peaks could not be matched to known phases. Assemblages of silicates were formed that incorporated the Sr, Rb, and Ba ions. Gas evolution during sintering to 1000°C was significant (35% weight loss for the CCD-PEG waste-loaded clay), with significant water being evolved at approximately 600°C.

  10. On mobility of cesium-137, sodium, potassium in various types of soils and prediction of cesium-137 cumulation in agricultural plants

    International Nuclear Information System (INIS)

    Ashkinazi, Eh.I.

    1990-01-01

    Mobility of cesium-137, sodium and potassium in the natural environment in podzolic gray and chernozem medium-loamy, sward podzolic sandy soils and chernozem has been studied. Durability of fixation of cesium-137 increases in a number of soils and increase of the level of metabolic potassium. Coefficient of transition of level of metabolic cesium-137 by potassium and sodium, and of sodium by potassium. The mentioned above coefficients can be used for the prediction of cesium-137 cumulation in plants

  11. Cesium carbonate mediated exclusive dialkylation of active methylene compounds

    Directory of Open Access Journals (Sweden)

    Ulaganathan Sankar

    2012-07-01

    Full Text Available Active methylene compounds are regioselectively dialkylated by variety of alkyl halides using cesium carbonate in quantitative yield. The reaction yielded exclusively dialkylated products with no intermediate monoalkyaltion or mixture of products.

  12. A model for radial cesium transport in a fuel pellet

    International Nuclear Information System (INIS)

    Imoto, Shosuke

    1989-01-01

    In order to explain the radial redistribution of cesium in an irradiated pellet, a two-step release model is proposed. The first step involves the migration of cesium by atomic diffusion to some channels, such as grain boundaries and cracks, and the second step assumes a thermomigration down along the temperature gradient. Distribution profiles of cesium are obtained by numerical calculation with the present model assuming a constant and spatially uniform birth rate of cesium in the pellet. The result agrees well with the profile observed by micro-gamma scanning for the LWR fuel in the outer region of the pellet but diverges from it at the inner region. Discussion is made on the steady-state model hitherto generally utilized. (orig.)

  13. Low-energy vibrational dynamics of cesium borate glasses.

    Science.gov (United States)

    Crupi, C; D'Angelo, G; Vasi, C

    2012-06-07

    Low-temperature specific heat and inelastic light scattering experiments have been performed on a series of cesium borate glasses and on a cesium borate crystal. Raman measurements on the crystalline sample have revealed the existence of cesium rattling modes in the same frequency region where glasses exhibit the boson peak (BP). These localized modes are supposed to overlap with the BP in cesium borate glasses affecting its magnitude. Their influence on the low frequency vibrational dynamics in glassy samples has been considered, and their contribution to the specific heat has been estimated. Evidence for a relation between the changes of the BP induced by the increased amount of metallic oxide and the variations of the elastic medium has been provided.

  14. Strontium-90 and cesium-137 in tea (Japanese tea)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in tea (Japanese tea) were determined. Five hundred grams of manufactured green tea was collected from six sampling locations in Japan. The results are shown in a table. (Namekawa, K.)

  15. Cesium pre-implantation of embedded biological sections

    International Nuclear Information System (INIS)

    Galle, Pierre; Levi-Setti, Riccardo; Labejof, Lise; Kaitasov, Odile

    2008-01-01

    An ion implantation system which allows the implantation of a large surface of a specimen has been used to obtain an homogeneous enrichment with cesium of embedded biological tissues sections. In such a specimen, containing already oxygen at a high concentration, the addition of cesium allows both positive and negative secondary ions to be studied with the highest sensitivity, using the same primary ion source.

  16. Nanotechnology-based gene-eluting stents.

    Science.gov (United States)

    Goh, Debbie; Tan, Aaron; Farhatnia, Yasmin; Rajadas, Jayakumar; Alavijeh, Mohammad S; Seifalian, Alexander M

    2013-04-01

    Cardiovascular disease is one of the major causes of death in the world. Coronary stenting in percutaneous coronary intervention (PCI) has revolutionized the field of cardiology. Coronary stenting is seen as a less invasive procedure compared to coronary artery bypass graft (CABG) surgery. Two main types of stents currently exist in the market: bare-metal stents (BMS) and drug-eluting stents (DES). DES were developed in response to problems associated with BMS use, like neointimal hyperplasia leading to restenosis. However, the use of DES engendered other problems as well, like late stent thrombosis (ST), which is a serious and lethal complication. Gene-eluting stents (GES) have recently been proposed as a novel method of circumventing problems seen in BMS and DES. Utilizing nanotechnology, sustained and localized delivery of genes can mitigate problems of restenosis and late ST by accelerating the regenerative capacity of re-endothelialization. Therefore this review seeks to explore the realm of GES as a novel alternative to BMS and DES, and its potential implications in the field of nanotechnology and regenerative medicine.

  17. Study of strontium and cesium migration in fractured crystalline rock

    International Nuclear Information System (INIS)

    Gustafsson, E.; Klockars, C.E.

    1984-01-01

    The purpose of this investigation has been to study the retardation and dilution of non-active strontium and cesium relative to a non-absorbing substance (iodide) in a well-defined fracture zone in the Finnsjoen field research area. The investigation was carried out in a previously tracer-tested fracture zone. The study has encompassed two separate test runs with prolonged injection of strontium and iodide and of cesium and iodide. The test have shown that: - Strontium is not retarded, but rather absorbed to about 40% at equilibrium. - At injection stop, 36.3% of the injected mass of strontium has been absorbed and there is no deabsorption. -Cesium is retarded a factor of 2-3 and absorbed to about 30% at equilibrium. - At injection stop, 39.4% of the injected mass of cesium has been absorbed. Cesium is deabsorbed after injection stop (400h) and after 1300 hours, only 22% of the injected mass of cesium is absorbed. (author)

  18. Seasonal variation of cesium 134 and cesium 137 in semidomestic reindeer in Norway after the Chernobyl accident

    Directory of Open Access Journals (Sweden)

    I.M. H. Eikelmann

    1990-09-01

    Full Text Available The Chernobyl accident had a great impact on the semidomestic reindeer husbandry in central Norway. Seasonal differences in habitat and diet resulted in large variations in observed radiocesium concentrations in reindeer after the Chernobyl accident. In three areas with high values of cesium-134 and cesium-137 in lichens, the main feed for reindeer in winter, reindeer were sampled every second month to monitor the seasonal variation and the decrease rate of the radioactivity. The results are based on measurements of cesium-134 and cesium-137 content in meat and blood and by whole-body monitoring of live animals. In 1987 the increase of radiocesium content in reindeer in Vågå were 4x from August to January. The mean reductions in radiocesium content from the winter 1986/87 to the winter 1987/88 were 32%, 50% and 43% in the areas of Vågå, Østre-Namdal and Lom respectively.

  19. TMI-2 core debris-cesium release/settling test. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    Akers, D W; Johnson, D A

    1984-12-01

    Cesium release, turbidity and airborne potential tests were conducted on 50 grams of TMI-2 core debris materials. The tests were performed on the debris in two conditions: on the as-received core debris specimen, and after crushing the debris to alter the particle size distribution. The crushing was intended to simulate the breakup of TMI-2 core material that may occur during reactor defueling. These tests are intended to assist GPU Nuclear in predicting the effect of defueling on the reactor environment.

  20. Cesium Accumulation and Growth Characteristics of Rhodococcus erythropolis CS98 and Rhodococcus sp. Strain CS402

    OpenAIRE

    Tomioka, Noriko; Uchiyama, Hiroo; Yagi, Osami

    1994-01-01

    Growth and cesium accumulation characteristics of two cesium-accumulating bacteria isolated from soils were investigated. Rhodococcus erythropolis CS98 and Rhodococcus sp. strain CS402 accumulated high levels of cesium (approximately 690 and 380 μmol/g [dry weight] of cells or 92 and 52 mg/g [dry weight] of cells, respectively) after 24 h of incubation in the presence of 0.5 mM cesium. The optimum pH for cesium uptake by both Rhodococcus strains was 8.5. Rubidium and cesium assumed part of th...

  1. Improving elution strategies for Chelex®-DGT passive samplers.

    Science.gov (United States)

    Devillers, Delphine; Buzier, Rémy; Charriau, Adeline; Guibaud, Gilles

    2017-12-01

    Elution of Chelex® binding layers, commonly used for the diffusive gradients in thin films technique (DGT), is recognized as the most important contributor to the uncertainty of DGT measurements. Limiting uncertainty requires the use of optimized procedures and suitable elution recoveries (f e ). This work therefore investigated elution robustness to propose improved strategies. A wide range of conditions were investigated for the main elution parameters (Chelex® particle size, elution time, Chelex® loading, and eluent concentration and volume) on Al(III), Cd(II), Co(II), Cr(III), Cu(II), Ni(II), Pb(II), and Zn(II). Results showed that the choice of elution conditions should be a compromise driven by study constrains in terms of accuracy, repeatability, sensitivity, and targeted elements. Using experimentally determined recoveries should improve accuracy by approximately 5 to 10% compared to the use of recoveries from the literature. Fast elution of 1 h can be achieved without significant loss of recovery and repeatability except for Cr(III) (8 h minimum). Elution recovery depended on Chelex® loading for Zn and Cr and introducing recoveries adapted to the loading could improve accuracy up to, respectively, 11 and 27%. When standard recoveries are used, a 0.85 f e value would be more appropriate than the common value of 0.8 to minimize inaccuracy (except for Cr). Some flexibility can be applied to elution conditions without a significant change in recovery for most elements: HNO 3 concentration of 1-15 M, volume of 1-2 mL, duration of 8-48 h. Cr(III) was unique in its sensitivity to elution condition variations; thus, choice is more restricted for this element. Graphical abstract Decisional tree for choosing elution procedure and recoveries for Chelex®-DGT.

  2. Adsorption and elution of uranium in seawater

    International Nuclear Information System (INIS)

    Kanno, M.

    1980-01-01

    In Japan, the essentiality of the development of nuclear power generation has become enhanced, and it needs to ensure uranium resources mainly from foreign countries. Though several policies have been taken, extraction of uranium from seawater has been interesting, and some investigations have been carried out mainly by the Metal Mining Agency of Japan since 1975. In this program, selections of chemical processes, adsorption tests mainly with hydrous titanium oxide, elution processes, washing processes, the recovery of eluate by steam stripping or electrodialysis, secondary concentrations of uranium in the eluate by ion exchange or ion flotation, etc., and some tentative cost estimations have been carried out. Some results of the experiments for each unit process will be described

  3. Hypotonic elution, a new desorption principle in immunoadsorbent chromatography

    DEFF Research Database (Denmark)

    Danielsen, Erik Michael; Sjöström, H; Norén, O

    1982-01-01

    of finding an efficient means of elution which is not denaturing to neither the purified enzyme nor the immunoadsorbent column. Common properties of the microvillar enzymes with regard to amphiphilicity, glycosylation or subunit composition could hypothetically account for the similar elution properties...

  4. Thermal Performance Analysis For Small Ion-Exchange Cesium Removal Process

    International Nuclear Information System (INIS)

    Lee, S.; King, W.

    2009-01-01

    media. Although, the safety temperature limit is based on the salt solution boiling point which does not apply in the air-filled case (because there is no liquid), this same limit (130C) is used as a measure for the evaluation of this condition as well. The primary objective of the present work is to develop models to simulate the thermal performance of the RF column design when the media is fully loaded with radioactive cesium and the central cooling tube is excluded. Previous analysis led to the consideration of this design simplification for RF, since the baseline column design with center cooling was developed assuming that CST media would be used for cesium removal which has a higher volumetric heat load. Temperature distributions and maximum temperatures across the column during SCIX process operations and upset conditions were conducted with a focus on SCIX implementation at Hanford. However, a feed composition and cesium loading were assumed which were known to be considerably higher than would typically be observed at Hanford. In order to evaluate the impact of this potentially highly conservative assumption, fractionally-reduced loading cases were also considered. A computational modeling approach was taken to include conservative, bounding estimates for key parameters so that the results would provide the maximum temperatures achievable under the design configurations.

  5. Dosimetry of a Cesium 137 source

    International Nuclear Information System (INIS)

    Torres R, J.G.; Manzanares A, E.; Vega C, H.R.

    2005-01-01

    It was carried out a dosimetric study of a source of Cesium 137 used in investigations of Radiobiology. This radionuclide has a half life of 30.07 years and it emits photons of 661.657 keV with a probability of 85.2%. The source has been used in a series of experiments trending to observe the cellular response before the gamma rays, as well as for the calibration of equipment of radiological protection. For such reason it is important to determine the dosimetric properties. In this work it was determined the absorbed dose that this source takes when being placed in the center from a methylmethacrylate badge to three distances, 5, 10 and 15 cm. The dose was measured with thermoluminescent dosemeters and it was calculated by means of Monte Carlo method, also was derived an expression that allows to determine the dose starting from the information of the activity of the source and of the distance regarding the same one. (Author)

  6. Zotarolimus-eluting vs. sirolimus-eluting coronary stents in patients with and without acute coronary syndromes

    DEFF Research Database (Denmark)

    Thim, Troels; Maeng, Michael; Kaltoft, Anne Kjer

    2012-01-01

    Eur J Clin Invest 2012 ABSTRACT: Objectives:  To compare clinical outcomes among patients with acute coronary syndrome treated with zotarolimus-eluting and sirolimus-eluting stents in the SORT OUT III trial. Background:  Currently, only limited data allow direct comparison of clinical outcomes...

  7. Measurements of cesium and strontium diffusion in biotite gneiss

    International Nuclear Information System (INIS)

    Skagius, K.; Neretnieks, I.

    1988-01-01

    A significant retardation of radionuclides transported by flowing water from an underground repository can be expected if the nuclides are able to diffuse into the water filled micropores in the rock. This diffusion into the pores will also increase the surface available to interactions between the nuclides in the ground water and the rock material, such as sorption. To calculate the retardation, it is necessary to know the sorption properties and the diffusivities in the rock matrix for the radionuclides. Diffusion experiments with cesium and strontium in biotite gneiss samples have been performed. Both the transport of strontium and cesium through rock samples and the concentration profiles of cesium and strontium inside rock samples have been determined. The result shows that diffusion of cesium and strontium occurs in the rock material. A diffusion model has been used to evaluate the diffusivity. Both pore diffusion and surface diffusion had to be included in the model to give good agreement with the experimental data. If surface diffusion is not included in the model, the effective pore diffusivity that gives the best fit to the experimental data is found to be higher than expected from earlier measurement of iodide diffusion in the same type of rock material. This indicates that the diffusion of cesium and strontium (sorbing components) in rock material is caused by both pore diffusion and surface diffusion acting in parallel

  8. Accumulation of strontium 90 and cesium 137 in some hydrobionts

    International Nuclear Information System (INIS)

    Boyadzhiev, A.; Keslev, D.; Kerteva, A.; Novakova, E.

    1974-01-01

    Factors responsible for the accumulation of strontium 90 and cesium 137 in some plant organisms, characteristic for fishes in Bulgarian fresh-water reservoirs and in Black Seawater, were examined. The investigated samples were taken during spring, summer and autumn-winter seasons 1967/1968. Each sample burnt to ashes at 450 0 C was examined for strontium 90 and cesium 137 content as well as stable isotopes of calcuim and potassium. Accumulation factors for strontium 90 and cesium 137 were significantly higher in freshwater hydrobionts than in seawater hydrobionts. This could be explained by variations in the concentration of stable isotopes of calcium and potassium from freshwater reservoirs and from seawater. Potassium and calcium concentrations were relatively constant in seawater while in freshwater they were significantly variable. Accumulation factors for these radionuclides increased according to the amount of rain and the altitude above sea level. Strontium 90 was deposited mostly in fins, less in scales and least in the meat of fishes; cesium 137 was mainly deposited in the meat and less in the other parts of fishes. The highest accumulation factors for strontium 90 were determined in fishes and for cesium 137 in plant organisms. The most convenient plant and fish species for tracing radioactive contamination of freshwater reservoirs and in the Black Sea were indicated. (A.B.)

  9. Adsorption of Radioactive Cesium to Illite-Sericite Mixed Clays

    Science.gov (United States)

    Hwang, J. H.; Choung, S.; Park, C. S.; Jeon, S.; Han, J. H.; Han, W. S.

    2016-12-01

    Once radioactive cesium is released into aquatic environments through nuclear accidents such as Chernobyl and Fukushima, it is harmful to human and ecological system for a long time (t1/2 = 30.2 years) because of its chemical toxicity and γ-radiation. Sorption mechanism is mainly applied to remove the cesium from aquatic environments. Illite is one of effective sorbent, considering economical cost for remediation. Although natural illite is typically produced as a mixture with sericite formed by phyllic alteration in hydrothermal ore deposits, the effects of illite-sericite mixed clays on cesium sorption was rarely studied. This study evaluated the sorption properties of cesium to natural illite collected at Yeongdong in Korea as the world-largest illite producing areas (termed "Yeongdong illite"). The illite samples were analyzed by XRF, XRD, FT-IR and SEM-EDX to determine mineralogy, chemical composition, and morphological characteristics, and used for batch sorption experiments. Most of "Yeongdong illite" samples predominantly consist of sericite, quartz, albite, plagioclase feldspar and with minor illite. Cesium sorption distribution coefficients (Kd,Cs) of various "Yeongdong illite" samples ranged from 500 to 4000 L/kg at low aqueous concentration (Cw 10-7 M). Considering Kd,Cs values were 400 and 6000 using reference sericite and illite materials, respectively, in this study, these results suggested that high contents of sericite significantly affect the decrease of sorption capabilities for radiocesium by natural illite (i.e., illite-sericite mixed clay).

  10. The Role of Desorption Kinetics on the Colloid-Facilitated Transport of Cesium and Strontium in a Partially-Saturated Quartz Sand Column

    Science.gov (United States)

    Dittrich, T. M.; Ryan, J. N.; Saiers, J. E.

    2010-12-01

    Colloid-facilitated transport (CFT) is a mechanism for enhanced transport of contaminants under certain environmental conditions. In order for CFT to be significant, three conditions must be met: (1) colloids must be present at a significant concentration, 2) the contaminant must associate with and remain associated with the colloids, and 3) colloids must be transported faster than the contaminant on its own. Colloids are often present in significant concentrations; therefore, CFT strongly depends on slow desorption kinetics and colloid mobility. The goal of this research was to identify and quantify the effects of desorption kinetics on the transport of cesium and strontium through a quartz sand column at different degrees of saturation (moisture contents). Breakthrough experiments were conducted using a rainfall simulator suspended over a column (12.7 cm diameter, 33.5 cm depth) packed with clean, sieved quartz sand (d50 = 360 µm). The effluent was collected with a fraction collector. Cesium and strontium were used as model contaminants because they are common contaminants found on Department of Energy sites in the US and because they have contrasting sorption kinetics with illite, which was used as the model colloid. The column was instrumented with three tensiometers and three moisture sensors to ensure uniform flow under partially-saturated conditions. Relative saturations of 0.33, 0.80, and 1.0 were established in the column. For aqueous breakthrough experiments, solutions at pH 7.3 containing cesium or strontium at a concentration of 7.5 x 10-6 M were applied to the top of the column until breakthrough (C/C0 > 0.5) was achieved. Following breakthrough, the solution was switched to a cesium- or strontium-free pH 7.3 solution for about 40 pore volumes. These experiments were repeated with the addition of illite colloids at a concentration of 100 mg L-1 in equilibrium with the cesium of strontium solution. Cesium and strontium breakthrough was monitored by

  11. Removal of cesium ions from clays by cationic surfactant intercalation.

    Science.gov (United States)

    Park, Chan Woo; Kim, Bo Hyun; Yang, Hee-Man; Seo, Bum-Kyoung; Moon, Jei-Kwon; Lee, Kune-Woo

    2017-02-01

    We propose a new approach to remediate cesium-contaminated clays based on intercalation of the cationic surfactant dodecyltrimethylammonium bromide (DTAB) into clay interlayers. Intercalation of DTAB was found to occur very rapidly and involved exchanging interlayer cations. The reaction yielded efficient cesium desorption (∼97%), including of a large amount of otherwise non-desorbable cesium ions by cation exchange with ammonium ions. In addition, the intercalation of DTAB afforded an expansion of the interlayers, and an enhanced desorption of Cs by cation exchange with ammonium ions even at low concentrations of DTAB. Finally, the residual intercalated surfactants were easily removed by a decomposition reaction with hydrogen peroxide in the presence of Cu 2+ /Fe 2+ catalysts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Controllable evaporation of cesium from a dispenser oven.

    Science.gov (United States)

    Fantz, U; Friedl, R; Fröschle, M

    2012-12-01

    This instrument allows controlled evaporation of the alkali metal cesium over a wide range of evaporation rates. The oven has three unique features. The first is an alkali metal reservoir that uses a dispenser as a cesium source. The heating current of the dispenser controls the evaporation rate allowing generation of an adjustable and stable flow of pure cesium. The second is a blocking valve, which is fully metallic as is the body of the oven. This construction both reduces contamination of the dispenser and enables the oven to be operated up to 300 °C, with only small temperature variations (dispenser oven can be easily transferred to the other alkali-metals.

  13. Sorption kinetics of cesium on hydrous titanium dioxide

    International Nuclear Information System (INIS)

    Altas, Y.; Tel, H.; Yaprak, G.

    2003-01-01

    Two types of hydrous titanium dioxide possessing different surface properties were prepared and characterized to study the sorption kinetics of cesium. The effect of pH on the adsorption capacity were determined in both type sorbents and the maximum adsorption percentage of cesium were observed at pH 12. To elucidate the kinetics of ion-exchange reaction on hydrous titanium dioxide, the isotopic exchange rates of cesium ions between hydrous titanium dioxides and aqueous solutions were measured radiochemically and compared with each other. The diffusion coefficients of Cs + ion for Type1 and Type2 titanium dioxides at pH 12 were calculated as 2.79 x 10 -11 m 2 s -1 and 1.52 x 10 -11 m 2 s -1 , respectively, under particle diffusion controlled conditions. (orig.)

  14. Cesium 137 in oils and plants from Guatemala

    International Nuclear Information System (INIS)

    Ayala, R.E.; Perez, J.F.

    1993-01-01

    Since 1990 the project of radioactive and environmental contamination started in Guatemala. Studies about the radioactive contamination levels are made within the framework of this project. Cesium-137 has been an interest radionuclide, because it is a fission product released to the environment by the use of nuclear weapons and nuclear power plants accidents. The sampling consisted in collection of soil and grass in 20 provinces of Guatemala, one point by province, and it was made in 1990. The cesium-137 concentration in the samples, was determined by gamma spectrometry, using an hyper pure germanium detector. The results show the presence of radioactive contamination in soil and grass due to cesium-137, at levels that might be considered as normal. The levels found are not harmful for human health, and its importance is the fact that can be used as reference levels for the environmental radioactivity monitoring in Guatemala

  15. Cesium in the Savannah River Site environment

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Bauer, L.R.; Evans, A.G.; Geary, L.A.; Murphy, C.E. Jr.; Pinder, J.E.; Strom, R.N.

    1992-03-01

    Cesium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fourth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. The earlier documents describe the environmental consequences of tritium, iodine, and uranium. Documents on plutonium, strontium, carbon, and technetium will be published in the future. These are dynamic documents and current plans call for revising and updating each one on a two-year schedule.Radiocesium exists in the environment as a result of above-ground nuclear weapons tests, the Chernobyl accident, the destruction of satellite Cosmos 954, small releases from reactors and reprocessing plants, and the operation of industrial, medical, and educational facilities. Radiocesium has been produced at SRS during the operation of five production reactors. Several hundred curies of [sup 137]Cs was released into streams in the late 50s and 60s from leaking fuel elements. Smaller quantities were released from the fuel reprocessing operations. About 1400 Ci of [sup 137]Cs was released to seepage basins where it was tightly bound by clay in the soil. A much smaller quantity, about four Ci. was released to the atmosphere. Radiocesium concentration and mechanisms for atmospheric, surface water, and groundwater have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases on the offsite maximum individual can be characterized by total doses of 033 mrem (atmospheric) and 60 mrem (liquid), compared with a dose of 12,960 mrem from non-SRS sources during the same period of time. Isotope [sup 137]Cs releases have resulted in a negligible risk to the environment and the population it supports.

  16. Cesium in the Savannah River Site environment

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Bauer, L.R.; Evans, A.G.; Geary, L.A.; Murphy, C.E. Jr.; Pinder, J.E.; Strom, R.N.

    1992-03-01

    Cesium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fourth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. The earlier documents describe the environmental consequences of tritium, iodine, and uranium. Documents on plutonium, strontium, carbon, and technetium will be published in the future. These are dynamic documents and current plans call for revising and updating each one on a two-year schedule.Radiocesium exists in the environment as a result of above-ground nuclear weapons tests, the Chernobyl accident, the destruction of satellite Cosmos 954, small releases from reactors and reprocessing plants, and the operation of industrial, medical, and educational facilities. Radiocesium has been produced at SRS during the operation of five production reactors. Several hundred curies of {sup 137}Cs was released into streams in the late 50s and 60s from leaking fuel elements. Smaller quantities were released from the fuel reprocessing operations. About 1400 Ci of {sup 137}Cs was released to seepage basins where it was tightly bound by clay in the soil. A much smaller quantity, about four Ci. was released to the atmosphere. Radiocesium concentration and mechanisms for atmospheric, surface water, and groundwater have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases on the offsite maximum individual can be characterized by total doses of 033 mrem (atmospheric) and 60 mrem (liquid), compared with a dose of 12,960 mrem from non-SRS sources during the same period of time. Isotope {sup 137}Cs releases have resulted in a negligible risk to the environment and the population it supports.

  17. Cesium in the Savannah River Site environment

    International Nuclear Information System (INIS)

    Carlton, W.H.; Bauer, L.R.; Evans, A.G.; Geary, L.A.; Murphy, C.E. Jr.; Pinder, J.E.; Strom, R.N.

    1992-03-01

    Cesium in the Savannah River Site Environment is published as a part of the Radiological Assessment Program (RAP). It is the fourth in a series of eight documents on individual radioisotopes released to the environment as a result of Savannah River Site (SRS) operations. The earlier documents describe the environmental consequences of tritium, iodine, and uranium. Documents on plutonium, strontium, carbon, and technetium will be published in the future. These are dynamic documents and current plans call for revising and updating each one on a two-year schedule.Radiocesium exists in the environment as a result of above-ground nuclear weapons tests, the Chernobyl accident, the destruction of satellite Cosmos 954, small releases from reactors and reprocessing plants, and the operation of industrial, medical, and educational facilities. Radiocesium has been produced at SRS during the operation of five production reactors. Several hundred curies of 137 Cs was released into streams in the late 50s and 60s from leaking fuel elements. Smaller quantities were released from the fuel reprocessing operations. About 1400 Ci of 137 Cs was released to seepage basins where it was tightly bound by clay in the soil. A much smaller quantity, about four Ci. was released to the atmosphere. Radiocesium concentration and mechanisms for atmospheric, surface water, and groundwater have been extensively studied by Savannah River Technology Center (SRTC) and ecological mechanisms have been studied by Savannah River Ecology Laboratory (SREL). The overall radiological impact of SRS releases on the offsite maximum individual can be characterized by total doses of 033 mrem (atmospheric) and 60 mrem (liquid), compared with a dose of 12,960 mrem from non-SRS sources during the same period of time. Isotope 137 Cs releases have resulted in a negligible risk to the environment and the population it supports

  18. Sericitization of illite decreases sorption capabilities for cesium

    Science.gov (United States)

    Choung, S.; Hwang, J.; Han, W.; Shin, W.

    2017-12-01

    Release of radioactive cesium (137Cs) to environment occurs through nuclear accidents such as Chernobyl and Fukushima. The concern is that 137Cs has long half-life (t1/2 = 30.2 years) with chemical toxicity and γ-radiation. Sorption techniques are mainly applied to remove 137Cs from aquatic environment. In particular, it has been known well that clay minerals (e.g, illite) are effective and economical sorbents for 137Cs. Illite that was formed by hydrothermal alteration exist with sericite through "sericitization" processes. Although sericite has analogous composition and lattice structure with illite, the sorptive characteristics of illite and sericite for radiocesium could be different. This study evaluated the effects of hydrothermal alteration and weathering process on illite cesium sorption properties. Natural illite samples were collected at Yeongdong area in Korea as the world-largest hydrothermal deposits for illite. The samples were analyzed by XRF, XRD and SEM-EDX to determine mineralogy, chemical compositions and morphological characteristics, and used for batch sorption experiments. The Yeongdong illites predominantly consist of illite, sericite, quartz, and albite. The measured cesium sorption distribution coefficients (Kd,Cs) of reference illite and sericite were approximately 6000 and 400 L kg-1 at low aqueous concentration (Cw 10-7 M), respectively. In contrast, Kd,Cs values for the Yeongdong illite samples ranged from 500 to 4000 L kg-1 at identical concentration. The observed narrow and sharp XRD peak of sericite indicated that the sericite has better crystallinity compared to illite. These experimental results suggested that sericitization processes of illite can decline the sorption capabilities of illite for cesium under various hydrothermal conditions. In particular, weathering experiments raised the cesium sorption to illite, which seems to be related to the increase of preferential sorption sites for cesium through crystallinity destruction

  19. Adsorption of iodine and cesium onto some cement materials

    Energy Technology Data Exchange (ETDEWEB)

    Mine, Tatsuya [Mitsui Shipbuilding and Engineering Co. Ltd., Tokyo (Japan); Mihara, Morihiro; Ito, Masaru [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works; Kato, Hiroshige [IDC, Tokai, Ibaraki (Japan)

    1997-06-01

    Cement materials, being expected to be used in structural materials in underground disposals of radioactive wastes, may adsorb nuclides resulting in retardation of their migration in environment. In this report adsorption behaviors of cement pastes toward iodine (as anion) and cesium (as cation) were studied. Adsorption of iodine was remarkable for OPC and MHP pastes that are known to have high molar ratio CaO/SiO{sub 2}, partition coefficient being 100 ml/g for initial tracer concentration of 10{sup -5} mol/l. Partition coefficient for cesium for PFA paste was found to be 5 ml/g on average. (S. Ohno)

  20. Strontium-90 and cesium-137 in freshwater from May 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Strontium-90 and cesium-137 in freshwater measured in May 1984 are given in pCi/l. The sampling point is 1, Kasumigaura-Lake (Ibaraki). Collection and pretreatment of samples, preparation of samples for analysis, separation of strontium-90 and cesium-137, determination of stable strontium, calcium and potassium, and counting are described. The sample was passed through a cation exchange column. After the radiochemical separation, the mounted precipitates were counted for activity using low background beta counters normally for 60 minutes. (Mori, K.)

  1. Cesium-137: psychological and social consequences of the Goiania's accident

    International Nuclear Information System (INIS)

    Helou, Suzana; Costa Neto, Sebastiao Benicio da

    1995-01-01

    The book care for radioactive accident occurred in 1987 in Goiania - brazilian city. The accident had origin by the hospitable equipment incorrect handling which contained a stainless steel capsule, in which interior there was cesium-137 chloride. The main boarded aspects are: psychological and social aspects verified after the accident; psychological and social analysis of population of Goiania three years after the accident; essay on the pertinence of Luscher's abbreviate test in psychological evaluation of the radioactive accident victims of Goiania; and psychological and mobile evaluation of intra-uterus children exposed to the radiation with cesium-137

  2. A modern generation of drug-eluting stents. Focusing on a sirolimus-eluting stent Calypso

    Directory of Open Access Journals (Sweden)

    А. Н. Кудряшов

    2017-04-01

    Full Text Available The review deals with the evolution of interventional coronary procedures and development of the state-of-art coronary stent market. Emphasis in the review is placed on comprehensive analysis of technical characteristics of the world’s most popular coronary stents versus a Russian bioresorbable sirolimus-eluting stent “Calipso”.Received 13 January 2017. Accepted 17 March 2017.Conflict of interest: Kudryashov A.N., Trebushat D.V. are “Angioline” Company employees, the producer of “Kalipso” coronary stent. Kretov E.I. served as executive editor of “Endovascular surgery” section. All other authors declare no conflict of interest.

  3. Pilot unit for cesium-137 separation; Unite pilote de separation du cesium-137

    Energy Technology Data Exchange (ETDEWEB)

    Raggenbass, A.; Quesney, M.; Fradin, J.; Dufrene, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Users of radiation are becoming increasingly interested in cesium-137. At the same time the starting up of the industrial plant at Marcoule will make available in the near future large stocks of fission products which should be made use of as quickly as possible. The installation described is a pilot plant for cesium-137 production which should make it possible: - to verify the chemical method on actual solutions of fission products, by treating about 100 curies of {sup 137}Cs by operation, - to obtain technical information on the chemical equipment (tele-commands, corrosion, maintenance, etc...), - to obtain {sup 137}Cs in sufficient quantity to perfect the technique of the manufacture of sealed sources. (author)Fren. [French] L'interet des utilisateurs de rayonnement se porte de plus en plus vers le caesium-137. Parallelement, la mise en oeuvre de l'ensemble industriel de Marcoule nous permettra de disposer dans un avenir proche de stocks importants de produits de fission qu'il sera interessant de valoriser au plus vite. L'installation que nous decrivons est un pilote de production de caesium-137 qui doit nous permettre: - de verifier la methode chimique sur des solutions de produits de fission reelles en traitant environ 100 curies de {sup 137}Cs par operation; - d'obtenir des renseignements techniques sur l'appareillage chimique (telecommandes, corrosion, entretien, etc...); - d'obtenir du {sup 137}Cs en quantite suffisante pour mettre au point la technique de fabrication des sources scellees. (auteur)

  4. Kuldkaru elutöö eest / Endel Link

    Index Scriptorium Estoniae

    Link, Endel

    2001-01-01

    Ameerika näitleja Kirk Douglas (1916), kellele seekordsel Berlinalel antakse elutöö eest Kuldkaru. Austamisõhtul näidatakse teda Stanley Kubricku kaua keelu all olnud filmis "Tee kuulsusele " ("Paths of Glory") : 1957

  5. Elutähtsatele teenustele koidab reform / Oliver Kund

    Index Scriptorium Estoniae

    Kund, Oliver

    2014-01-01

    Osana laiapindse riigikaitse ülesehitamisest on kavas elutähtsate teenuste arv praeguse 45ga võrreldes kokku tõmmata. Nii loodetakse tõsta teenuste olulisust ja nende tagamise nimel pingutataks rohkem

  6. Drug-Eluting Stents: Do They Increase Heart Attack Risk?

    Science.gov (United States)

    ... intervention, or PCI). Drug-eluting stents have a polymer coating over mesh that emits a drug over ... Advisory Panel meeting on the Absorb Bioresorbable Vascular Scaffold System. JACC: Cardiovascular Interventions. 2016;9:1757. FDA ...

  7. Nickel elution properties of contemporary interatrial shunt closure devices.

    Science.gov (United States)

    Verma, Divya Ratan; Khan, Muhammad F; Tandar, Anwar; Rajasekaran, Namakkal S; Neuharth, Renée; Patel, Amit N; Muhlestein, Joseph B; Badger, Rodney S

    2015-02-01

    We sought to compare nickel elution properties of contemporary interatrial shunt closure devices in vitro. There are two United States Food and Drug Administration (FDA)-approved devices for percutaneous closure of secundum atrial septal defect: the Amplatzer septal occluder (ASO; St Jude Medical Corporation) and Gore Helex septal occluder (HSO; W.L. Gore & Associates). The new Gore septal occluder (GSO) device is in clinical trials. These are also used off-label for patent foramen ovale closure in highly selected patients. These devices have high nickel content. Nickel allergy is the most common reason for surgical device explantation. Nickel elution properties of contemporary devices remain unknown. We compared nickel elution properties of 4 devices - ASO, GSO, HSO, and sternal wire (SW) - while Dulbecco's phosphate-buffered saline (DPBS) served as control. Three samples of each device were submerged in DPBS. Nickel content was measured at 14 intervals over 90 days. Nickel elution at 24 hours, compared to control (0.005 ± 0.0 mg/L), was significantly higher for ASO (2.98 ± 1.65 mg/L; P=.04) and SW (0.03 ± 0.014 mg/L; P=.03). Nickel levels at 90 days, compared to control (0.005 ± 0.0 mg/L) and adjusting for multiple comparisons, were significantly higher for ASO (19.80 ± 2.30 mg/L; P=.01) and similar for HSO (P=.34), GSO (P=.34), and SW (P=.34). ASO had significantly higher nickel elution compared to HSO, GSO, and SW (P=.01). There is substantial variability in nickel elution; devices with less exposed nickel (HSO and GSO) have minimal elution. The safety of low nickel elution devices in patients with nickel allergy needs to be evaluated in prospective trials.

  8. The Role of Partially-Saturated Conditions, Physical Heterogeneity, and Desorption Kinetics on Colloid-Facilitated Transport of Cesium and Strontium by Illite in Quartz Sand

    Science.gov (United States)

    Dittrich, T. M.; Ryan, J. N.; Saiers, J. E.

    2009-12-01

    In many soil and groundwater systems, colloids are present, mobile, and capable of enhancing the transport of some contaminants if the rate of contaminant desorption from the contaminants is slow relative to the rate of colloid and contaminant transport. The importance of contaminant desorption kinetics has been well illustrated in saturated porous media systems, but not in partially-saturated systems. The goal of this research project was to examine and quantify the effects of contaminant desorption kinetics on colloid-facilitated transport under partially-saturated conditions. Laboratory breakthrough experiments were conducted using a column (12.7 cm diameter and 33.5 cm length) packed with (1) quartz sand of uniform size and (2) quartz sand of two different sizes packed as a central tube simulating a macropore (coarse sand) and surrounding matrix (fine sand). Illite was used as the colloids. Cesium and strontium were chosen as model contaminants because their mechanisms of adsorption to illite result in slower desorption of cesium than of strontium and because these cations are found in their radioactive forms at contaminated Department of Energy sites. In the partially saturated columns of uniform sand, the illite colloids facilitated the transport of both cesium and strontium; however, the transport of cesium was facilitated to a greater extent than strontium because cesium binds strongly to the frayed edge sites on the illite colloids. Compared to saturated conditions, partially-saturated conditions increased the transport of cesium and strontium due to the decreased effective surface area of the quartz sand. At moisture contents near saturation, addition of a macropore increased transport of cesium and strontium due to increased porewater movement through the macropore. At lower moisture contents, less porewater was transported through the macropore and cesium and strontium transport was similar to the uniform sand experiments. A model for colloid

  9. Solubility of cesium iodide crystals in aliphatic alchohols

    International Nuclear Information System (INIS)

    Kulikova, N.V.; Kulikov, B.A.

    1988-01-01

    Solubility of cesium iodide crystals in CH 3 OH, C 2 H 5 OH, C 3 H 7 OH, C 4 H 9 OH, C 5 H 11 OH, C 8 H 17 OH aliphatic alcohols at 20, 40, 60 and 80 deg C is determined by conductometric and potentiometric techniques. Equations of solubility correlation with solvent permittivity are presented

  10. Strontium-90 and cesium-137 in fresh water

    International Nuclear Information System (INIS)

    1978-01-01

    Japan Chemical Analysis Center has analysed the strontium-90 and Cesium-137 contents in fresh water from 7 prefectures in Japan by the commission of Science and Technology Agency of Japanese Government. The method described in ''Radioactivity Survey Data in Japan No. 43 (NIRS-RSD-43, 1977) was applied to the analysis of these two radionuclides in samples. (author)

  11. Preparation of cesium targets for gamma-spectroscopic studies

    Science.gov (United States)

    Bhattacharyya, S.; Basu, S. K.; Chanda, S.; Deb, P.; Eqbal, Md; Kundu, S.; Joseph, D.

    2000-11-01

    A procedure to prepare monoisotopic cesium compound targets for gamma-spectroscopic experiments is described. Using this procedure, uniform targets up to thicknesses of 0.6-1.2 mg/cm 2 were prepared and used for in-beam spectroscopic studies. The purity of the target was tested by energy dispersive X-ray fluorescence (EDXRF) measurements.

  12. Fission-product tellurium and cesium telluride chemistry revisited

    International Nuclear Information System (INIS)

    McFarlane, J.; LeBlanc, J.C.

    1996-11-01

    The chemistry of fission-product tellurium is discussed with a focus on conditions in an operating CANDU reactor and in an accident scenario, i.e., a loss of coolant accident (LOCA). Cesium telluride, Cs 2 Te, is likely to be one of the most abundant tellurium species released to containment. Available thermodynamic data on gas phase Cs 2 Te is not complete; hence the volatility of cesium telluride was studied by Knudsen-cell mass spectrometry. Cesium telluride was found to vapourize incongruently, becoming more tellurium-rich in the condensed phase as vapourization progressed. Vapour-phase species that were observed were elemental cesium and tellurium, CsTe, Cs 2 Te, Cs 2 Te 2 and Cs 2 Te 3 . Second-law enthalpies and entropies were obtained for many of these species, and a third-law value, ΔH 298 o , of 186 ± 2 kJ·mol -1 was obtained for Cs 2 Te. (author)

  13. Cesium-137 accumulation in higher plants before and after Chernobyl

    International Nuclear Information System (INIS)

    Sawidis, T.; Drossos, E.; Papastefanou, C.; Heinrick, G.

    1990-01-01

    Cesium-137 concentrations in plant species of three biotypes of northern Greece, differing in location as well as in vegetation, are reported following the Chernobyl reactor accident. The cesium uptake by plants was due to the foliar deposition rather than the root uptake. The highest level of cesium in plants was found in Ranunculus sardous, a pubescent plant. The 137 Cs concentration was about 22kBq kg -1 d.w. A high level of cesium was also found in Salix alba ( 137 Cs: 19.6 kBq kg -1 d.w.), a deciduous tree showing that hairy leaves or leaves having rough and large surfaces can absorb greater amounts of radioactivity (surface effect). A comparison is also made between the results of measurements of the present study and the results of measurements of some herbarium plants collected one year before the accident as well as the results of measurements of some new plants grown and collected one year after the accident resulting in a natural removal rate of 137 Cs in plants varying from 14 to 130 days

  14. Absolute coverage of the saturated cesium silicon interfaces

    Science.gov (United States)

    Sherman, William Benjamin

    Metal/semiconductor interfaces are of great interest for a variety of reasons. They shed light on surface metal/semiconductor transitions, and they form Schottky barriers, which are of scientific as well as significant technological importance (primarily for the production of high speed, low-power logic circuitry). The cesium/silicon interfaces are of particular interest since the oxide forms a Negative Electron Affinity state. Cesium does not mix with the bulk silicon, so the interface is very abrupt, and the electronic structure of cesium is easier to understand than that of the transition metals. Further, cesium (like other alkali metals at room temperature) forms a single atomic layer on the various silicon faces and then the coverage saturates (i.e. atoms stop sticking to the surface). This makes the cesium/silicon interfaces ideal model systems of the metal/semiconductor interface. In spite of their importance, the detailed structures of the cesium saturated silicon faces are still uncertain. Numerous structural models have been proposed and many of them have quite different absolute coverages. Thus absolute coverage measurements can effectively distinguish between the various models. Rutherford Backscattering Spectrometry (RBS) provides an ideal measurement of absolute coverage since its results can be directly interpreted without dependence upon any structural model. A new beam line has been set up on the Laboratory for Research on the Structure of Matter's tandem accelerator. The Ultrahigh Vacuum system is equipped with an Auger Electron Spectrometer, a Low Energy Electron Diffraction system, a retarding field method work function analyzer, a cesium doser, a Medium Energy Ion Scattering two dimensional toroidal analyzer and a Rutherford Backscattering: Spectrometry (RBS) solid state ion detector. It has been used to manufacture saturated Cs/Si(100)-2 x 1 and Cs/Si(111)-7 x 7 interfaces and measure their absolute coverage via RBS. The coverage for the Si

  15. Investigation of the elution by seawater of caesium and strontium from loaded clinoptilolite

    International Nuclear Information System (INIS)

    Harder, B.R.; Mitchell, I.H.; Smyth, M.J.

    1985-07-01

    Simple investigations of the elution of caesium and strontium from loaded clinoptilolite are described. The clinoptilolite was loaded to levels expected in the British Nuclear Fuels plc SIXEP plant and contacted with seawater at approx. 15 C. (The elution time was measured until about 99% of the caesium and strontium had been eluted.) It was found that 99% of the caesium was eluted in 35 hours but the strontium (with more variable results) took at least 400 hours for 99% elution. (author)

  16. Biolimus-eluting biodegradable polymer-coated stent versus durable polymer-coated sirolimus-eluting stent in unselected patients receiving percutaneous coronary intervention (SORT OUT V)

    DEFF Research Database (Denmark)

    Christiansen, Evald Høj; Jensen, Lisette Okkels; Thayssen, Per

    2013-01-01

    Third-generation biodegradable polymer drug-eluting stents might reduce the risk of stent thrombosis compared with first-generation permanent polymer drug-eluting stents. We aimed to further investigate the effects of a biodegradable polymer biolimus-eluting stent compared with a durable polymer...

  17. Efficacy and safety of zotarolimus-eluting and sirolimus-eluting coronary stents in routine clinical care (SORT OUT III): a randomised controlled superiority trial

    DEFF Research Database (Denmark)

    Rasmussen, Klaus; Maeng, Michael; Kaltoft, Anne

    2010-01-01

    In low-risk patients, the zotarolimus-eluting stent has been shown to reduce rates of restenosis without increasing the risk of stent thrombosis. We compared the efficacy and safety of the zotarolimus-eluting stent versus the sirolimus-eluting stent in patients with coronary artery disease who were...

  18. Clinical outcomes after treatment of multiple lesions with zotarolimus-eluting versus sirolimus-eluting coronary stents (a SORT OUT III substudy)

    DEFF Research Database (Denmark)

    Thim, Troels; Maeng, Michael; Lassen, Jens Flensted

    2012-01-01

    Data on clinical outcomes among patients treated with the zotarolimus-eluting Endeavor™ stent versus the sirolimus-eluting Cypher™ stent favor the sirolimus-eluting stent. However, a separate comparison of clinical outcome among patients treated for multiple lesions with these stents is lacking. We...

  19. Thermal stability and expansion studies of cesium molybdates and cesium thorium molybdates

    Energy Technology Data Exchange (ETDEWEB)

    Keskar, Meera, E-mail: meerakeskar@yahoo.com; Sali, S.K.; Dahale, N.D.; Krishnan, K.; Kulkarni, N.K.; Phatak, R.; Kannan, S.

    2013-07-15

    In Cs–Mo–O system, Cs{sub 2}Mo{sub n}O{sub 3n+1} (n = 1, 3, 5 and 7) were prepared by solid state route and n = 7 was established as the highest stable analog. Differential thermal analysis of the compound Cs{sub 2}MoO{sub 4} (n = 1) in air showed a reversible phase transition followed by melting whereas compounds with n = 3, 5 and 7 did not show any phase transition up to their melting temperatures. Thermal expansion of all the molybdates were studied in vacuum using high temperature X-ray diffraction method. In quaternary Cs–Th–Mo–O system, Cs{sub 2}Th(MoO{sub 4}){sub 3} and Cs{sub 4}Th(MoO{sub 4}){sub 4} were synthesized by reacting cesium molybdate and thorium molybdate in 1:1 and 2:1 M ratios, respectively, at 873 K in air. Both compounds did not show any phase transition up to the melting and the compounds showed positive thermal expansion when heated in vacuum in the temperature range of 298–873 K.

  20. Stent Fracture after Everolimus-Eluting Stent Implantation

    Directory of Open Access Journals (Sweden)

    Ali S. Almasood

    2011-01-01

    Full Text Available Compared with bare-metal stents, drug-eluting stents (DES have greatly reduced the risk of in-stent restenosis (ISR by inhibiting neointimal growth. Nevertheless, DES are still prone to device failure, which may lead to cardiac events. Recently, stent fracture (SF has emerged as a potential mechanism of DES failure that is associated with ISR. Stent fracture is strongly related to stent type, and prior reports suggest that deployment of sirolimus eluting stents (SES may be associated with a higher risk of SF compared to other DES. Everolimus eluting stents (EESs represent a new generation of DES with promising results. The occurrence of SF with EES has not been well established. The present paper describes two cases of EES fracture associated with ISR.

  1. Immunoglobulin G elution in protein A chromatography employing the method of chromatofocusing for reducing the co-elution of impurities.

    Science.gov (United States)

    Pinto, Nuno D S; Uplekar, Shaunak D; Moreira, Antonio R; Rao, Govind; Frey, Douglas D

    2017-01-01

    Purification processes for monoclonal Immunoglobulin G (IgG) typically employ protein A chromatography as a capture step to remove most of the impurities. One major concern of the post-protein A chromatography processes is the co-elution of some of the host cell proteins (HCPs) with IgG in the capture step. In this work, a novel method for IgG elution in protein A chromatography that reduces the co-elution of HCPs is presented where a two-step pH gradient is self-formed inside a protein A chromatography column. The complexities involved in using an internally produced pH gradient in a protein A chromatography column employing adsorbed buffering species are discussed though equation-based modeling. Under the conditions employed, ELISA assays show a 60% reduction in the HCPs co-eluting with the IgG fraction when using the method as compared to conventional protein A elution without affecting the IgG yield. Evidence is also obtained which indicates that the amount of leached protein A present in free solution in the purified product is reduced by the new method. Biotechnol. Bioeng. 2017;114: 154-162. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. Preclinical evaluation of new indomethacin-eluting biodegradable urethral stent.

    Science.gov (United States)

    Kotsar, Andres; Nieminen, Riina; Isotalo, Taina; Mikkonen, Joonas; Uurto, Ilkka; Kellomäki, Minna; Talja, Martti; Moilanen, Eeva; Tammela, Teuvo L J

    2012-04-01

    To evaluate the effect of an indomethacin-eluting biodegradable urethral stent on the production of inflammatory cytokines in vitro and the degradation and biocompatibility of the new stent in vivo. The effects of an indomethacin and indomethacin-eluting biodegradable stent on monocyte chemoattractant protein (MCP)-1, RANTES (regulated on activation, normal T-cell expressed and secreted), and transforming growth factor-ß were measured in THP-1 cells by enzyme-linked immunosorbent assay. Stents (copolymer of L-lactide and glycolide acid) that were coated with 50L/50D polylactic acid and two different concentrations of indomethacin were inserted into the rabbit urethra. Stents without the drug were used as controls. Scanning electron microscopy (SEM) was used to assess the degradation of the stents. Biocompatibility was evaluated using histologic analyses of the urethral specimen. The measurements were performed at 3 weeks and 3 months. Indomethacin and indomethacin-releasing stent material inhibited MCP-1 and RANTES production in activated THP-1 macrophages. SEM analysis revealed that indomethacin coating had no effect on the degradation process of the stents and less epithelial polyposis had developed in the indomethacin stent group. In histologic analyses at 3 weeks, indomethacin-eluting stents caused more calcification but no significant differences in other tissue reactions. At 3 months, the indomethacin-eluting stents caused less inflammatory reaction and calcification compared with the control stents. Indomethacin-eluting property can be safely added to biodegradable stents without major influence on the degradation time. The development of epithelial polyposis in the urethra can be potentially reduced by the new indomethacin-eluting urethral stents.

  3. Strontium-90 and cesium-137 in total diet

    International Nuclear Information System (INIS)

    1977-01-01

    Under the commission of Science and Technology Agency, Japan Chemical Analysis Center has analysed total diet samples collected from 30 prefectures (2 times per year), and determined to content of strontium-90 and cesium-137 in these samples. Each Prefectural public health laboratories and institutes have collected all the daily regular diet consumed for five persons, namely three meals and other eating between meals, for radiochemical analysis in polyethylene containers. These samples were collected to Japan Chemical Analysis Center after carbonization without smoke rising in the large stainless dish. At Japan Chemical Analysis Center, these samples were asked in an electric muffle furnance. And the ask to which both some carriers and hydrochloric acid were added, was destroyed under heating. The nuclides were dissolved into hydrochloric acid and filtrated, after it was added with nitric acid and heated to dryness. The filtrates was analysed for strontium-90 and cesium-137 using the method recommended by Science and Technology Agency. (author)

  4. Strontium-90 and cesium-137 in service water

    International Nuclear Information System (INIS)

    1979-01-01

    Prefectural public health laboratories and institutes and Japan Chemical Analysis Center have analysed the contents of strontium-90 and cesium-137 in service water under the commission of Science and Technology Agency. At each prefectural public health laboratories and institutes, 100 literes of service water (8 prefectures, water from the intake of each station of water works) and tap water (32 prefectures) were collected as sample twice a year. The samples were filtrated with large filter papers after addition and mixture of both some carries. The filtration was then applied on a column filled the sodium cation exchange resin, and all the cations were absorbed on it. These resin and filter papers were collected at Japan Chemical Analysis Center. At Japan Chemical Analysis Center, these collected samples were radiochemically analysed for strontium-90 and cesium-137 using the method applied for the analysis of rain and dry fallout materials. (author)

  5. Cesium-137, a drama recounted; Cesio-137, um drama recontado

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Suzane de Alencar

    2013-01-15

    The radiological accident with Cesium-137, which started on Goiania in 1987, did not stop with the end of radiological contamination and continues in a judicial, scientific and narrative process of identification and recognition of new victims. The drama occupies a central place on the dynamics of radiological event, as it extends its limits, inflects its intensity and updates the event. As a narrative of the event, the ethnography incorporates and brings up to date the drama as an analysis landmark and the description of the theme as it is absorbed by a dramatic process. Cesium-137, a drama recounted is a textual experimentation based on real events and characters picked out from statements reported in various narratives about the radiological accident. (author)

  6. A cesium-sputtering negative ion source for AMS investigations

    Science.gov (United States)

    Håkansson, K.; Hellborg, R.; Erlandsson, B.; Skog, G.; Stenström, K.; Wiebert, A.

    1996-02-01

    Accelerator mass spectrometry (AMS) requires ion sources delivering intense negative ion beams of high stability. At the Lund 3 MV Pelletron tandem accelerator a new Cs-sputtering source has therefore been constructed and installed. The source is equipped with a mechanism for automatically cracking the cesium galss ampoule inside the oven when the source is evacuated. The source is also equipped with a multiple sample holder which permits on-line sample changing without disrupting the operation of the electrostatic accelerator. In order to maximise the negative ion beam current the sample holder has a mechanism for moving the sample relative to the cesium beam. By doing this the lifetime of the samples can be increased.

  7. Web technology in the separation of strontium and cesium from INEL-ICPP radioactive acid waste (WM-185)

    International Nuclear Information System (INIS)

    Bray, L.A.; Brown, G.N.

    1995-01-01

    Strontium and cesium were successfully removed from radioactive acidic waste (WM-185) at the Idaho National Engineering Laboratory, Idaho Chemical Processing Plant (ICPP), with web technology from 3M and IBC Advanced Technologies, Inc. (IBC). A technical team from Pacific Northwest Laboratory, ICPP, 3M and IBC conducted a very successful series of experiments from August 15 through 18, 1994. The ICPP, Remote Analytical Laboratory, Idaho Falls, Idaho, provided the hot cell facilities and staff to complete these milestone experiments. The actual waste experiments duplicated the initial 'cold' simulated waste results and confirmed the selective removal provided by ligand-particle web technology

  8. Hypotonic elution, a new desorption principle in immunoadsorbent chromatography

    DEFF Research Database (Denmark)

    Danielsen, Erik Michael; Sjöström, H; Norén, O

    1982-01-01

    -phlorizin hydrolase (EC 3.2.1.23-62) and maltase-glucoamylase (EC 3.2.1.20). This elution method proved capable of achieving an acceptable yield (30-70%) while at the same time preserving the purified enzymes in an enzymically active state. It hereby offers a solution to the problem in immunoadsorbent chromatography...... of the enzymes but were considered unlikely on several grounds. Hypotonic elution in immunoadsorbent chromatography, therefore, may have a much broader range of applicability, and the method is recommended to be tried out by workers in other areas of protein chemistry....

  9. Extraction of cesium and strontium from nuclear waste

    Science.gov (United States)

    Davis, Jr., Milton W.; Bowers, Jr., Charles B.

    1988-01-01

    Cesium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4'(5) [1-hydroxy-2-ethylhexyl]benzo 18-crown-6 compound and a cation exchanger in a matrix solution. Strontium is extracted from acidified nuclear waste by contacting the waste with a bis 4,4'(5') [1-hydroxyheptyl]cyclohexo 18-crown-6 compound, and a cation exchanger in a matrix solution.

  10. Percutaneous radiation therapy of peyronie's disease with 137cesium

    International Nuclear Information System (INIS)

    Schreiber, B.; Rossbach, T.; Schmitt, G.; Essen Univ.

    1978-01-01

    From 1966 to 1977, 49 patients suffering from Peyronie's disease received percutaneous radiation treatment with 137 Cesium ( 137 Cs). Therapy results were followed up for a period of from 2 months to 11 years. The method of 137 Cs radiation is described and the results compared with other forms of therapy. Percutaneous radiation therapy with 137 Cs seems to be the preferred treatment of Peyronie's disease because of its few side effects, rapid effectiveness, and low cost. (orig.) [de

  11. Cesium contamination of mosses in county Vas, Hungary

    International Nuclear Information System (INIS)

    Golya, I.; Sebestyen, R.

    1993-01-01

    Two species of mosses were examined to assess radiocesium contamination of Vas county, and to analyse some aspects of mosses for use as indicator of radioactive contamination. Experimental results demonstrated that the distribution of contamination in a given region could be characterized by the cesium contamination of mosses. Sampling sites should be selected with special attention paid to spots with high contamination. Regression analysis proved that the contamination of mosses originated from Chernobyl fallout. (author) 4 refs.; 2 figs

  12. Comparison of Durable-Polymer Zotarolimus-Eluting and Biodegradable-Polymer Biolimus-Eluting Coronary Stents in Patients With Coronary Artery Disease

    DEFF Research Database (Denmark)

    Raungaard, Bent; Christiansen, Evald H; Bøtker, Hans Erik

    2017-01-01

    OBJECTIVES: The authors sought to compare the safety and efficacy of the biocompatible durable-polymer zotarolimus-eluting stent with the biodegradable-polymer biolimus-eluting stent in unselected coronary patients. BACKGROUND: Biodegradable-polymer biolimus-eluting stents are superior to first......:1) to receive either the zotarolimus-eluting (1,502 patients) or the biolimus-eluting (1,497 patients) stent. At 3-year follow-up, MACE occurred in 128 (8.6%) patients assigned to the durable-polymer zotarolimus-eluting stent and in 144 (9.6%) assigned to the biodegradable-polymer biolimus-eluting stent (p = 0...... to the durable-polymer zotarolimus-eluting stent and in 10 (0.7%) assigned to the biodegradable-polymer biolimus-eluting stent (p = 0.33). CONCLUSIONS: At 3-year follow-up, the durable-polymer zotarolimus-eluting stent and the biodegradable-polymer biolimus-eluting stent were similar in clinical outcome...

  13. Test procedures and instructions for Hanford complexant concentrate supernatant cesium removal using CST

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, D.W.

    1997-01-08

    This document provides specific test procedures and instructions to implement the test plan for the preparation and conduct of a cesium removal test, using Hanford Complexant Concentrate supernatant liquor from tank 241-AN-107, in a bench-scale column. The cesium sorbent to be tested is crystalline silicotitanate. The test plan for which this provides instructions is WHC-SD-RE-TP-023, Hanford Complexant Concentrate Supernatant Cesium Removal Test Plan.

  14. Test procedures and instructions for Hanford tank waste supernatant cesium removal

    Energy Technology Data Exchange (ETDEWEB)

    Hendrickson, D.W., Westinghouse Hanford

    1996-05-31

    This document provides specific test procedures and instructions to implement the test plan for the preparation and conduct of a cesium removal test using Hanford Double-Shell Slurry Feed supernatant liquor from tank 251-AW-101 in a bench-scale column.Cesium sorbents to be tested include resorcinol-formaldehyde resin and crystalline silicotitanate. The test plan for which this provides instructions is WHC-SD-RE-TP-022, Hanford Tank Waste Supernatant Cesium Removal Test Plan.

  15. Separation of radio cesium from PUREX feed solution by sorption on composite ammonium molybdo phosphate (AMP)

    International Nuclear Information System (INIS)

    Singh, I.J.; Achuthan, P.V.; Jain, S.; Janardanan, C.; Gopalakrishnan, V.; Wattal, P.K.; Ramanujam, A.

    2001-01-01

    Composite AMP exchanger was developed and evaluated for separation of radio cesium from dissolver solutions of PUREX process using a column experiment. The composite shows excellent sorption of radio cesium from dissolver solutions without any loss of plutonium and uranium. The removal of radio cesium from dissolver solutions will help in lowering the degradation of tri-n-butyl phosphate (TBP) in the solvent extraction process and will also help in reducing the radiation related problems. (author)

  16. Example of cesium sorption database in natural minerals

    International Nuclear Information System (INIS)

    Yokoyama, Shingo; Nakata, Kotaro; Yamada, Hirohisa; Tamura, Kenji; Watanabe, Yujiro; Sato, Tsutomu; Ito, Kenichi; Hatta, Tamao

    2013-01-01

    In the database of the National Institute for Materials Science (MatNavi), the adsorption data of cesium, strontium, and iodine have been published. Among these data, the authors picked up the data of cesium adsorption against natural ores, which were measured and compiled by the authors, graphically expressed them for clarifying the overall trends, and described each mineral’s adsorption characteristics and future challenges. The partition coefficients for the following minerals are compiled: bentonite, acid clay, montmorillonite, beidellite, vermiculite, illite, mordenite, zeolite, etc. Many of the recorded data in MatNavi are the data obtained in the systems without existence of a large amount of competing ions. On the other hand, in the accumulated water at the Fukushima Daiichi Nuclear Power Station, competing ions due to seawater are contained. In the immersion liquid of incineration fly ash and the immersion liquid of plants/vegetation, too, competing ions are considered to be contained. Accumulation of adsorption data under different solution conditions are considered important. In addition, the concentrations of radioactive cesium in decontamination target are lower values by 5-7 orders, compared with the lower limit of 0.01 ppm in the existing data. In face of experiments, the influence of adsorption to containers and filters cannot be neglected. (A.O.)

  17. Transition of cesium in food chains [after Chernobyl catastrophe

    International Nuclear Information System (INIS)

    Procházka, H.; Brunclík, T.; Jandl, J.; Jirásek, V.; Novosad, J.; Hampl, J.

    1990-01-01

    An investigation of 25,000 samples of foodstuffs and feedstuffs in Czechoslovakia, contaminated by fall-out cesium after the accident in the Chernobyl nuclear power plant, performed from May 5, 1986 to March 31, 1988, revealed that both the values of cesium transfer-factors in food--animal tissues--milk transitions and the values of biological half-life of cesium are functions of internal and external conditions of contamination. Organism individuality as the main internal condition causes the variance of about +/- 50% of the mean value of the respective transfer-factor. Through the external conditions, mainly the environmental contamination level, type of ingested food and time of ingestion, the mean values of transfer-factors are influenced up to 500%, e.g. to the value of 0.5. But this value converges with growing up contamination of food and environment to the limit of 0.3. The first two to three biological half-lives after the last ingestion of contaminated food are up to ten-times shorter than those at stabilized state

  18. Mineral-deposit model for lithium-cesium-tantalum pegmatites

    Science.gov (United States)

    Bradley, Dwight C.; McCauley, Andrew D.; Stillings, Lisa L.

    2017-06-20

    Lithium-cesium-tantalum (LCT) pegmatites comprise a compositionally defined subset of granitic pegmatites. The major minerals are quartz, potassium feldspar, albite, and muscovite; typical accessory minerals include biotite, garnet, tourmaline, and apatite. The principal lithium ore minerals are spodumene, petalite, and lepidolite; cesium mostly comes from pollucite; and tantalum mostly comes from columbite-tantalite. Tin ore as cassiterite and beryllium ore as beryl also occur in LCT pegmatites, as do a number of gemstones and high-value museum specimens of rare minerals. Individual crystals in LCT pegmatites can be enormous: the largest spodumene was 14 meters long, the largest beryl was 18 meters long, and the largest potassium feldspar was 49 meters long.Lithium-cesium-tantalum pegmatites account for about one-fourth of the world’s lithium production, most of the tantalum production, and all of the cesium production. Giant deposits include Tanco in Canada, Greenbushes in Australia, and Bikita in Zimbabwe. The largest lithium pegmatite in the United States, at King’s Mountain, North Carolina, is no longer being mined although large reserves of lithium remain. Depending on size and attitude of the pegmatite, a variety of mining techniques are used, including artisanal surface mining, open-pit surface mining, small underground workings, and large underground operations using room-and-pillar design. In favorable circumstances, what would otherwise be gangue minerals (quartz, potassium feldspar, albite, and muscovite) can be mined along with lithium and (or) tantalum as coproducts.Most LCT pegmatites are hosted in metamorphosed supracrustal rocks in the upper greenschist to lower amphibolite facies. Lithium-cesium-tantalum pegmatite intrusions generally are emplaced late during orogeny, with emplacement being controlled by pre-existing structures. Typically, they crop out near evolved, peraluminous granites and leucogranites from which they are inferred to be

  19. Comparative study of crystalline silico-titanate and composition of ammonium molybdophosphate - polyacrylonitrile as sorbents for cesium separation from acid solutions

    International Nuclear Information System (INIS)

    Todd, T.A.; Romanovskij, V.N.

    2005-01-01

    Crystalline silico-titanate (UOP) and ammonium molybdophosphate - polyacrylonitrile (AMP-PAN) are tested as sorbents for purification from cesium of concentrated acid wastes of Idaho National Engineering and Ecological Laboratory (INEEL). Using solutions simulating concentrated wastes isotherms of sorption equilibrium are built. Experiments on nonequilibrium sorption are done in columns with 1.5 cm 3 volume with flow rate 5, 10, and 20 1/h. Results obtained are compared for two sorbents [ru

  20. Cesium Toxicity Alters MicroRNA Processing and AGO1 Expressions in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Il Lae Jung

    Full Text Available MicroRNAs (miRNAs are short RNA fragments that play important roles in controlled gene silencing, thus regulating many biological processes in plants. Recent studies have indicated that plants modulate miRNAs to sustain their survival in response to a variety of environmental stimuli, such as biotic stresses, cold, drought, nutritional starvation, and toxic heavy metals. Cesium and radio-cesium contaminations have arisen as serious problems that both impede plant growth and enter the food chain through contaminated plants. Many studies have been performed to define plant responses against cesium intoxication. However, the complete profile of miRNAs in plants during cesium intoxication has not been established. Here we show the differential expression of the miRNAs that are mostly down-regulated during cesium intoxication. Furthermore, we found that cesium toxicity disrupts both the processing of pri-miRNAs and AGONOUTE 1 (AGO1-mediated gene silencing. AGO 1 seems to be especially destabilized by cesium toxicity, possibly through a proteolytic regulatory pathway. Our study presents a comprehensive profile of cesium-responsive miRNAs, which is distinct from that of potassium, and suggests two possible mechanisms underlying the cesium toxicity on miRNA metabolism.

  1. Removal of radioactive cesium from soil by ammonium citrate solution and ionic liquid

    International Nuclear Information System (INIS)

    Ishiwata, Shunji; Kitakouji, Manabu; Taga, Atsushi; Ogata, Fumihiko; Ouchi, Hidekazu; Yamanishi, Hirokuni; Inagaki, Masayo

    2015-01-01

    Radioactive cesium has strongly bound soil as time proceeded, which could not be cleaved in mild condition. We have found that serial treatment of ammonium citrate solution and ionic liquid removed radioactive cesium from soil effectively. The sequence of the treatment is crucial, since inverse serial treatment or mixture of two kinds of solution did not show such an effect, which suggested that ammonium citrate unlocked trapped cesium in soil and ionic liquid solved it. We also found that repeating serial treatment and prolonged treatment time additively removed cesium from soil. (author)

  2. Structure of cesium loaded iron phosphate glasses: An infrared and Raman spectroscopy study

    International Nuclear Information System (INIS)

    Joseph, Kitheri; Premila, M.; Amarendra, G.; Govindan Kutty, K.V.; Sundar, C.S.; Vasudeva Rao, P.R.

    2012-01-01

    The structure of cesium loaded iron phosphate glasses (IPG) was investigated using infrared and Raman spectroscopy. The spectra of the cesium doped samples revealed a structural modification of the parent glass owing to the incorporation of cesium. The structural changes could be correlated with the variation observed in the glass transition temperature of these glasses. Increased Cs-mediated cationic cross linking appears to be the reason for the initial rise in glass transition temperature up to 21 mol% Cs 2 O in IPG; while, breakdown of the phosphate network with increasing cesium content, brings down the glass transition temperature.

  3. Next-generation drug-eluting stents in coronary artery disease: focus on everolimus-eluting stent (Xience V®

    Directory of Open Access Journals (Sweden)

    Imad Sheiban

    2008-02-01

    Full Text Available Imad Sheiban1, Gianluca Villata1, Mario Bollati1, Dario Sillano1, Marzia Lotrionte2, Giuseppe Biondi-Zoccai11Interventional Cardiology, Division of Cardiology, University of Turin, Turin, Italy; 2Institute of Cardiology, Catholic University, Rome, ItalyAbstract: Percutaneous coronary revascularization has been a mainstay in the management of coronary artery disease since its introduction in the late 1970s. Bare-metal stents and, more recently, first-generation drug-eluting stents (DES, such as sirolimus-eluting (Cypher® and paclitaxel-eluting stents (Taxus®, have further improved results of percutaneous coronary intervention (PCI by improving early results and reducing the risk of restenosis. There is currently debate on the safety of these first-generation DES, given the potential for late stent thrombosis, especially after discontinuation of dual antiplatelet therapy. There are well known caveats on the performance of their respective metallic stent platforms, delivery, and dilation systems, and polymer coatings. Second-generation DES, such as zotarolimus-eluting (Endeavor® and everolimus-eluting stents (Xience V®, have recently become available in the USA and/or Europe. The Xience V stent holds the promise of superior anti-restenotic efficacy as well as long-term safety. In addition, this stent is based on the Multi-link platform and delivery system. Recently available data already suggest the superiority of the Xience V stent in comparison to the Taxus stent in terms of prevention of restenosis, without significant untoward events. Nonetheless, the number of patients studied and the follow-up duration are still too limited to enable definitive conclusions. Only indirect meta-analyses can be used to date to compare the Xience V with the Cypher. This systematic review tries to provide a concise and critical appraisal of the data in support of the Xience V everolimus-eluting stent.Keywords: coronary artery disease, everolimus, percutaneous

  4. Radioactive cesium. Dynamics and transport in forestal food-webs; Radioaktivt cesium. Dynamik och transport i skogliga naeringsvaevar

    Energy Technology Data Exchange (ETDEWEB)

    Palo, T.; Nelin, P. [Swedish Univ. of Agricultural Sciences, Umeaa (Sweden). Dept. of Animal Ecology; Bergman, R.; Nylen, T. [FOA NBC Defence, Umeaa (Sweden)

    1995-12-01

    This report summarises results from a radioecological study during 1994-1995 concerning turnover, redistribution and loss of radioactive Cesium (134 and 137) in boreal forest ecosystems, as well as uptake and transfer in important food-chains over moose, vole and vegetation. The basis for this report are 9 publications published 1994-95. These reports are presented in summary form. 9 refs, 17 figs.

  5. Characteristics of radio-cesium transport and discharge between different basins near to the Fukushima Dai-ichi Nuclear Power Plant after heavy rainfall events.

    Science.gov (United States)

    Sakuma, Kazuyuki; Kitamura, Akihiro; Malins, Alex; Kurikami, Hiroshi; Machida, Masahiko; Mori, Koji; Tada, Kazuhiro; Kobayashi, Takamaru; Tawara, Yasuhiro; Tosaka, Hiroyuki

    2017-04-01

    This paper describes watershed modeling of catchments surrounding the Fukushima Dai-ichi Nuclear Power Plant to understand radio-cesium redistribution by water flows and sediment transport. We extended our previously developed three-dimensional hydrogeological model of the catchments to calculate the migration of radio-cesium in both sediment-sorbed and dissolved forms. The simulations cover the entirety of 2013, including nine heavy rainfall events, as well as Typhoon Roke in September 2011. Typhoons Man-yi and Wipha were the strongest typhoons in 2013 and had the largest bearing on radio-cesium redistribution. The simulated 137 Cs discharge quantities over the nine events in 2013 are in good agreement with field monitoring observations. Deposition mainly occurs on flood plains and points where the river beds broaden in the lower basins, and within dam reservoirs along the rivers. Differences in 137 Cs discharge ratios between the five basins are explained by differences in the initial fallout distribution within the basins, the presence of dam reservoirs, and the input supply to watercourses. It is possible to use these simulation results to evaluate future radioactive material distributions in order to support remediation planning. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Chemical and radiation stability of SuperLig{reg_sign}644, resorcinol-formaldehyde, and CS-100 cesium ion exchange materials

    Energy Technology Data Exchange (ETDEWEB)

    Brown, G.N.; Adami, S.R.; Bray, L.A. [and others

    1995-09-01

    At the request of the Initial Pretreatment Module Project within Westinghouse Hanford Company, Pacific Northwest Laboratory (PNL) conducted this study for the Efficient Separations and Processing Crosscutting Program (ESP) under the task ``Develop and Test Sorbents.`` The purpose of the study was to assess and compare the chemical and radiolytic stability of several cesium-selective ion exchange materials in simulated alkaline Hanford tank waste matrices. Pretreatment of nuclear process wastes to remove of cesium and other radionuclides by ion exchange was proposed previously as one method of minimizing the amount of high-level radioactive waste at Hanford. In this study, PNL evaluated three cesium-selective materials SuperLig{reg_sign}644, resorcinol-formaldehyde (R-F), and CS-100 for chemical and radiation stability in 1 M NaOH and a simulated neutralized current acid waste (NCAW). The objective of the study is to investigate the stability of the newly produced SuperLig{reg_sign}644 under a variety of conditions in an attempt to simulate and predict the degradation process. The following specific conclusions and recommendations resulted from the study.

  7. Chemical and radiation stability of SuperLig reg-sign 644, resorcinol-formaldehyde, and CS-100 cesium ion exchange materials

    International Nuclear Information System (INIS)

    Brown, G.N.; Adami, S.R.; Bray, L.A.

    1995-09-01

    At the request of the Initial Pretreatment Module Project within Westinghouse Hanford Company, Pacific Northwest Laboratory (PNL) conducted this study for the Efficient Separations and Processing Crosscutting Program (ESP) under the task ''Develop and Test Sorbents.'' The purpose of the study was to assess and compare the chemical and radiolytic stability of several cesium-selective ion exchange materials in simulated alkaline Hanford tank waste matrices. Pretreatment of nuclear process wastes to remove of cesium and other radionuclides by ion exchange was proposed previously as one method of minimizing the amount of high-level radioactive waste at Hanford. In this study, PNL evaluated three cesium-selective materials SuperLig reg-sign 644, resorcinol-formaldehyde (R-F), and CS-100 for chemical and radiation stability in 1 M NaOH and a simulated neutralized current acid waste (NCAW). The objective of the study is to investigate the stability of the newly produced SuperLig reg-sign 644 under a variety of conditions in an attempt to simulate and predict the degradation process. The following specific conclusions and recommendations resulted from the study

  8. Solid state cesium ion guns for surface studies

    International Nuclear Information System (INIS)

    Souzis, A.E.; Carr, W.E.; Kim, S.I.; Seidl, M.

    1990-01-01

    Three cesium ion guns covering the energy range of 5--5000 V are described. These guns use a novel source of cesium ions that combine the advantages of porous metal ionizers with those of aluminosilicate emitters. Cesium ions are chemically stored in a solid electrolyte pellet and are thermionically emitted from a porous thin film of tungsten at the surface. Cesium supply to the emitting surface is controlled by applying a bias across the pellet. A total charge of 10.0 C can be extracted, corresponding to greater than 2000 h of lifetime with an extraction current of 1.0 μA. This source is compact, stable, and easy to use, and produces a beam with >99.5% purity. It requires none of the differential pumping or associated hardware necessary in designs using cesium vapor and porous tungsten ionizers. It has been used in ultrahigh-vacuum (UHV) experiments at pressures of -10 Torr with no significant gas load. Three different types of extraction optics are used depending on the energy range desired. For low-energy deposition, a simple space-charge-limited planar diode with a perveance of 1x10 -7 A/V 3/2 is used. Current densities of 10.0 μA/cm 2 at the exit aperture for energies ≤20 V are typical. This type of source provides an alternative to vapor deposition with the advantage of precise flux calibration by integration of the ion current. For energies from 50 to 500 V and typical beam radii of 0.5 to 0.2 mm, a high perveance Pierce-type ion gun is used. This gun was designed with a perveance of 1x10 -9 A/V 3/2 and produces a beam with an effective temperature of 0.35 eV. For the energy range of 0.5 to 5 keV, the Pierce gun is used in conjunction with two Einzel lenses, enabling a large range of imaging ratios to be obtained. Beam radii of 60 to 300 μm are typical for beam currents of 50 nA to 1.0 μA

  9. Immunoglobulin G bound to ovine placenta is eluted by surgical ...

    African Journals Online (AJOL)

    Objective: To elute placental bound immunoglobulin G (IgG) in situ. Design: Laboratory based experimentation. Setting: Biological Sciences Department, The University of Newcastle Australia and the Department of Biochemistry, University of Nairobi, Kenya. Subjects: Twelve pregnant ewes 10 to 15 days before the onset of ...

  10. Tissue biocompatibility of new biodegradable drug-eluting stent materials.

    Science.gov (United States)

    Uurto, Ilkka; Kotsar, Andres; Isotalo, Taina; Mikkonen, Joonas; Martikainen, Paula M; Kellomäki, Minna; Törmälä, Pertti; Tammela, Teuvo L J; Talja, Martti; Salenius, Juha-Pekka

    2007-08-01

    Drug-eluting stents are a recent innovation for endovascular and endourethral purposes. The aim of this study was to assess the biocompatibility of new biodegradable drug-eluting stent materials in vivo. Rods made of SR-PLDLA (self-reinforced poly-96L,4D: -lactic acid) covered with P(50L/50D)LA and rods made of 96L/4D SR-PLA and covered with P(50L/50D)LA including indomethacin 3.3 microg/mm(2)or dexamethasone 1.5 microg/mm(2), were inserted into the dorsal muscles of 20 rabbits serving as test animals. Rods made of silicone and organotin-positive polyvinylchloride were used as negative and positive controls. The animals were sacrificed after 1 week, 1 month, 2 months or 4 months. Histological changes attributable to the operative trauma were seen in all specimens at 1 week and 1 month. At 2 months both dexamethasone and indomethacin induced less fibrosis than the plain SR-PLDLA covered with P(50L/50D)LA without drug. At 4 months dexamethasone induced both chronic inflammatory changes and foreign body reaction, whereas the reactions in the indomethacin and drug-free plain SR-PLDLA groups were insignificant. The new biodegradable drug-eluting stent materials are highly biocompatible. Drug-eluting biodegradable stents may offer a promising new treatment modality for vascular and urethral diseases. However, further studies are needed to demonstrate their feasibility and efficacy.

  11. Current manufacturing processes of drug-eluting sutures.

    Science.gov (United States)

    Champeau, Mathilde; Thomassin, Jean-Michel; Tassaing, Thierry; Jérôme, Christine

    2017-11-01

    Drug-eluting sutures represent the next generation of surgical sutures since they fulfill their mechanical functions but also deliver the drug in their vicinity after implantation. These implants are produced by a variety of manufacturing processes. Drug-eluting sutures represent the next generation of surgical sutures since they fulfill their mechanical functions but also deliver the drug in their vicinity after implantation. These implants are produced by a variety of manufacturing processes. Two general approaches can be followed: (i) the ones that add the API into the material during the manufacturing process of the suture and (ii) the ones that load the API to an already manufactured suture. Areas covered: This review provides an overview of the current manufacturing processes for drug-eluting suture production and discusses their benefits and drawbacks depending on the type of drugs. The mechanical properties and the drug delivery profile of drug-eluting sutures are highlighted since these implants must fulfill both criteria. Expert opinion: For limited drug contents, melt extrusion and electrospinning are the emerging processes since the drug is added during the suture manufacture process. Advantageously, the drug release profile can be tuned by controlling the processing parameters specific to each process and the composition of the drug-containing polymer. If high drug content is targeted, the coating or grafting of a drug layer on a pre-manufactured suture allows for preservation of the tensile strength requirements of the suture.

  12. Simulations

    CERN Document Server

    Ngada, Narcisse

    2015-06-15

    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  13. Sirolimus-eluting versus bare-metal stent implantation in patients with ostial lesions

    DEFF Research Database (Denmark)

    Jørgensen, Erik; Kelbæk, Henning; Kløvgaard, Lene

    2010-01-01

    To investigate the efficacy of implantation of sirolimus-eluting stents (SES) in the ostium of coronary arteries.......To investigate the efficacy of implantation of sirolimus-eluting stents (SES) in the ostium of coronary arteries....

  14. Cesium Carbonate-Catalyzed α-Phenylchalcogenation of Carbonyl Compounds with Diphenyl Dichalcogenide

    Directory of Open Access Journals (Sweden)

    Yutaka Nishiyama

    2009-09-01

    Full Text Available It was found that cesium carbonate has a unique catalytic ability on the reaction of carbonyl compounds with diphenyl diselenide to give the corresponding α-phenylseleno carbonyl compounds in moderate to good yields. Similarly, the α-phenylthiolation of carbonyl compounds with diphenyl disulfide was promoted by the cesium carbonate catalyst.

  15. Utilization of cesium-137 environmental contamination from fallout in erosion and sedimentation studies

    International Nuclear Information System (INIS)

    Guimaraes, M.F. da; Pessenda, L.C.R.; Fernandes, E.A.N.; Freire, O.; Nascimento Filho, V.F. do; Ferraz, E.S.B.

    1988-01-01

    The radioactivity of cesium-137 from fallout in different soils profiles for erosion and sedimentation studies are described. The potential of this technique for hydrographic basin in Piracicaba/Sao Paulo is evaluated. Due to the existence of natural radionuclides in soil, with energy near to cesium-137, the soil samples are determined by a high-purity Ge detectors. (author)

  16. Decorporation of mixture of strontium and cesium isotopes with domestic mineral waters

    International Nuclear Information System (INIS)

    Slavov, S.; Filev, G.; Kiradzhiev, G.

    1990-01-01

    The possibilities of Bulgarian mineral waters to decorporate mixtures of strontium and cesium radioisotopes, simultaneous entering the body, were studied. A modified effect in respect to radioactive strontium was found. Modification of the effect of mixing two diferent types of mineral waters was not proven. No effect was found of potassium-containing mineral water on radioactive cesium kinetics. 1 tab., 7 refs

  17. The effect of fertilizer application on 137 cesium accumulation in lucerne grown on a leached chernozem

    International Nuclear Information System (INIS)

    Konstantinov, G.; Kovachev, K.; Penchev, D.; Ermolaev, I.; Mirchev, M.

    1974-01-01

    On the basis of pot experiments, carried out in a glass-house the following conclusions on the effect of fertilizer application are made: nitrogen fertilizer application increases the amount of radioactive cesium in lucerne plants. Phosphorus fertilizer introduction, similarly to potassium fertilizer application decreases cesium uptake, resulting in an increase in available phosphorus in the soil. (M.Ts.)

  18. Cesium-137 uptake studies on ammonium phospho molybdate irradiated with electrons

    International Nuclear Information System (INIS)

    Rao, K.L.N.; Balasubramanian, K.R.; Shukla, J.P.

    1992-01-01

    Ammonium phospho molybdate is an important inorganic ion exchanger having high selectivity for cesium. This paper discusses the effects of electron irradiation to a dose of 1 mGy on this exchanger with special reference to its ion exchange performance using cesium-137 as a tracer. An explanation is attempted for the slight increase in the distribution coefficients. (author). 5 refs., 1 tab

  19. Study of the thermal diffusion of ion-alloyed cesium in aluminium, silicon and titanium by the Rutherford backscattering method

    International Nuclear Information System (INIS)

    Bulgakov, Yu.V.; Savel'eva, L.M.

    1987-01-01

    Thermal diffusion of cesium implanted at 120 keV energy in monocrystal silicon and in polycrystal aluminium and titanium is investigated by the method of Rutherford backscattering (RBS). Parameters of temperature dependence of the cesium diffusion coefficient in materials given above are determined. Cesium is shown to be one of the most movable impurities

  20. Cesium fallout in Norway after the Chernobyl accident

    International Nuclear Information System (INIS)

    Backe, S.; Bjerke, H.; Rudjord, A.L.; Ugletveit, F.

    1986-01-01

    Results of country-wide measurements of 137 Cs and 134 Cs in soil samples in Norway after the Chernobyl accident are reported. The results clearly demonstrates that municipalities in the central part of southern Norway, Troendelag and the southern part of Nordland, have been rather heavily contaminated. The total fallout of 137 Cs and 134 Cs from the Chernobyl accident in Norway is estimated to 2300 TBq and 1200 TBq, respectively. This is approximately 6% of the cesium activity released from the reactor

  1. Effect of illite particle shape on cesium sorption

    Science.gov (United States)

    Rajec, Pavol; Šucha, Vladimír; Eberl, Dennis D.; Środoń, Jan; Elsass, Françoise E.

    1999-01-01

    Samples containing illite and illite-smectite, having different crystal shapes (plates, “barrels”, and filaments), were selected for sorption experiments with cesium. There is a positive correlation between total surface area and Cs-sorption capacity, but no correlation between total surface area and the distribution coefficient, Kd. Generally Kd increases with the edge surface area, although “hairy” (filamentous) illite does not fit this pattern, possibly because elongation of crystals along one axis reduces the number of specific sorption sites.

  2. Low-temperature phase transformation in rubidium and cesium superoxides

    International Nuclear Information System (INIS)

    Alikhanov, R.A.; Toshich, B.S.; Smirnov, L.S.

    1980-01-01

    Crystal structures of rubidium and cesium superoxides which are two interpenetrating lattices of metal ions and oxygen molecule ions reveal a number of phase transformations with temperature decrease. Crystal-phase transformations in CsO 2 are 1-2, 2-3 and low temperature one 3-4 at 378, 190 and 10 K. Low temperature transition is considered as the instability of lattice quadrupoles of oxygen molecule ions to phase transformation of the order-disorder type. Calculated temperatures of low temperature phase transformations in PbO 2 and CsO 2 agree with experimental calculations satisfactory [ru

  3. System of fluorides and chromates of cesium and lead

    International Nuclear Information System (INIS)

    Belyaev, I.N.; Revina, O.Ya.

    1980-01-01

    The triple mutual system of CsF-Cs 2 CrO 4 -PbF 2 -PbCrO 4 hav been investigated by the visual-polythermal and, in part, by the thermographical methods with a view to find out the nature of reactions occurring in recrystallization of cesium and lead fluorides and chromates from a melt. The parameters of six nonvariant points have been determined. The system may be classified as an irreversibly-mutual stable cross-section diagonal analysis [ru

  4. Ternary phosphates of rubidium-cesium-rare earth element

    International Nuclear Information System (INIS)

    Mel'nikov, P.P.; Carrillo-Eredero, H.D.; Efremov, V.A.; Komissarova, L.N.; Quiroga, E.

    1986-01-01

    This article examines the possibility of the existence of ternary phosphates of the rare earth elements (REE) containing two large alkali cations in order to establish the morphological and physicochemical characteristics in the entire group of ternary REE phosphates. The synthesis of the ternary rubidium-cesium-REE phosphates was carried out with molten charges that did not contain an excess of components. Analysis for the uncommon alkali cations was done by the atomic absorption technique; for holmium, by complexometric titration; and for phosphorus, by gravimetry as NH 4 CdPO 4 . The data obtained fully confirm the composition of Rb 2 CsLn(PO 4 ) 2

  5. Standard method of test for radioactive cesium in water

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Concentrations of radioactive Cs greater than 1 μCi/l in water were determined by gamma counting after separation by extraction. The method is limited to 134 Cs, 136 Cs, 137 Cs, and 138 Cs. The radioactive Cs is extracted at pH 7.0 as cesium tetraphenylborate in amyl acetate with EDTA present to prevent the extraction of undesirable fission products. The γ activity of a sample of the organic phase is determined by γ spectroscopy. Large amounts of Na + , K + , Cs + , Rb + , NH 4 + , Ag + , and free acid interfere with the separation process in the procedure. The overall precision of the method is +-5 percent

  6. Sorption of trace cesium on 21 Hanford Site sediment types

    International Nuclear Information System (INIS)

    Routson, R.C.; Barney, G.S.; Smith, R.M.; Delegard, C.A.

    1980-03-01

    Sorption of trace cesium (Cs) was measured on 21 Hanford Site sediment types. A Box-Behnken statistical design was used to develop empirical-statistical equations predicting 137 Cs sorption as a function of the equilibrium concentrations of macroions Na + , K + , and Ca +2 in solution over the concentration ranges of 3.0 to 0.001M, 0.2 to 0.002M, and 0.2 to 0.002M, respectively. These equations are required to estimate trace Cs transport from Hanford ground disposal sites. Average Cs sorption equations for the 21 sediments will be presented and discussed

  7. Enhancing cognate target elution efficiency in gel-free chemical proteomics

    Directory of Open Access Journals (Sweden)

    Branka Radic-Sarikas

    2015-12-01

    Full Text Available Gel-free liquid chromatography mass spectrometry coupled to chemical proteomics is a powerful approach for characterizing cellular target profiles of small molecules. We have previously described a fast and efficient elution protocol; however, altered target profiles were observed. We hypothesised that elution conditions critically impact the effectiveness of disrupting drug-protein interactions. Thus, a number of elution conditions were systematically assessed with the aim of improving the recovery of all classes of proteins whilst maintaining compatibility with immunoblotting procedures. A double elution with formic acid combined with urea emerged as the most efficient and generically applicable elution method for chemical proteomics

  8. Drug-eluting stents in renal artery stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Zaehringer, M. [Marienhospital Stuttgart, Department of Radiology, Stuttgart (Germany); Pattynama, P.M.T. [Erasmus MC-University Medical Center Rotterdam, Rotterdam (Netherlands); Talen, A. [genae associates nv, Antwerp (Belgium); Sapoval, M. [Hopital Europeen Georges Pompidou, Service de Radiologie Cardio-Vasculaire, Paris (France); Inserm U 780 epidemiologie Cardio Vasculaire, Paris (France)

    2008-04-15

    Because of higher acute and long-term success rates compared with balloon angioplasty alone, percutaneous stent implantation has become an accepted therapy for the treatment of atherosclerotic renal artery stenosis. Restenosis rates after successful renal stent placement vary from 6 up to 40%, depending on the definition of restenosis, the diameter of the treated vessel segment and comorbidities. The safety and efficacy of drug-eluting stents for the treatment of renal-artery stenosis is poorly defined. The recently published GREAT study is the only prospective study, comparing bare-metal and sirolimus-coated low profile stent systems in renal artery stenosis, showing a relative risk reduction of angiographic binary in-stent restenosis by 50%. This is an opinion paper on indications, current treatment options and restenosis rates following renal artery stenting and the potential use of drug-eluting stents for this indication. (orig.)

  9. Biocompatibility of new drug-eluting biodegradable urethral stent materials.

    Science.gov (United States)

    Kotsar, Andres; Nieminen, Riina; Isotalo, Taina; Mikkonen, Joonas; Uurto, Ilkka; Kellomäki, Minna; Talja, Martti; Moilanen, Eeva; Tammela, Teuvo L J

    2010-01-01

    To investigate the effects of biodegradable stent material (poly-96L/4D-lactic acid [PLA]) on the production of cytokines and other inflammatory mediators in vitro and the biocompatibility of new drug-eluting biodegradable urethral stent materials in vivo. Indomethacin, dexamethasone, and simvastatin were used in the materials. The effects of the biodegradable stent material on cytokines and other inflammatory mediators were measured using the Human Cytokine Antibody Array and enzyme-linked immunosorbent assay in THP-1 cells, with bacterial lipopolysaccharide as a positive control. To assess the biocompatibility of the stent materials, we used muscle implantation. Biodegradable stent materials without drug-eluting properties and silicone and latex were used as controls. The measurements were done at 3 weeks and 3 months. The PLA stent material induced production of inflammatory mediators, especially interleukin-8, tumor necrosis factor-alpha, and transforming growth factor-beta, in vitro. The increase in the production of these mediators with the PLA stent material was smaller than in the cells treated with lipopolysaccharide. In vivo, the effects of the biodegradable materials did not differ at 3 weeks, although, at 3 months, dexamethasone had induced more tissue reactions than had the other materials. At 3 months, fibrosis and chronic inflammatory changes were decreased in the biodegradable material groups compared with the positive control. PLA stent material increased the production of cytokines and other inflammatory mediators less than did positive controls in vitro. The in vivo biocompatibility of the drug-eluting biodegradable materials was better than that of the positive controls. Drug-eluting biodegradable urethral stents could potentially offer a new treatment modality in the future. 2010 Elsevier Inc. All rights reserved.

  10. Bioresorbable drug-eluting scaffolds for treatment of vascular disease.

    Science.gov (United States)

    Suwannasom, Pannipa; Sotomi, Yohei; Tateishi, Hiroki; Tenekecioglu, Erhan; Zeng, Yaping; Kraak, Robin P; Wykrzykowska, Joanna J; De Winter, Robbert J; Serruys, Patrick W; Onuma, Yoshinobu

    2016-01-01

    Theoretical advantages of fully bioresorbable scaffold (BRS) stem from transient vessel support without rigid caging. Therefore, it could reduce long-term adverse events associated with the presence of foreign materials. This article will provide an overview of: drug-eluting BRS for various applications in the treatment of vascular disease; The mechanisms of active agent release from such scaffolds; currently available drug-eluting BRS and their future applications are also discussed. The current BRS have been developed in order to achieve optimal vascular patency while providing long-term safety. The clinical efficacy and safety of BRS in coronary treatment have been reported as equal to that of the current metallic drug eluting stents in simple lesions. The application of BRS can potentially be expanded to other vascular beds. The research in bioengineering for the appropriate materials should not only focus on biocompatibility but also should be tailored according to the sites of implantation, which may require different strength and supporting period. The ultimate goal in this field is to develop a biocompatible device that provides equivalent and complementary therapy to other devices, and is able to disappear when the mechanical support and drug delivery are no longer required.

  11. [Drug-eluting stent thrombosis and its pharmacological prevention].

    Science.gov (United States)

    Pershukov, I V; Batyraliev, T A

    2007-01-01

    The problem of drug eluting stents (DES) safety has been actively discussed throughout 2006 because of increase of frequency of development of late stent thromboses which were noted during almost 2 years after stenting. In December 2006 US Food and Drug Administration (FDA) advisory panel acknowledged increase of development of late stent thrombosis. At the same time FDA accepted new definition of stent-thrombosis suggested by the Academic Research Consortium. According to this definition thrombosis can be definite, probable and possible. Any unexplained death before end of follow-up in a trial should be considered thrombosis related. Recalculation of thrombosis rate using this definition caused pronounced increase of this parameter in previously conducted trials. Thrombosis rate rose from 0,6 to 3,3% for bare metal stents, from 0,8 to 3,6% for sirolimus eluting stents and from 1,3 to 3,5% for paclitaxel eluting stents. Professional cardiological and angiographical societies (ACC, AHA, SCAI) responding to FDA advisory panel published their proofs and vision of the problem of stent thrombosis. In February 2007 ACC, AHA, SCAI, American College of Surgeons and Association of Dentists published scientific bulletin in which described preventive measures aimed at lowering of risk of thrombosis development. This document contains strict recommendation to continue double antithrombotic therapy with aspirin and clopidogrel for 12 months after implantation of DES or abandonment of the use of this type of stents when long term double antithrombotic therapy is not possible.

  12. An Experimental Study of the Fluorescence Spectrum of Cesium Atoms in the Presence of a Buffer Gas

    Science.gov (United States)

    Davydov, V. G.; Kulyasov, V. N.

    2018-01-01

    A direct experiment is performed to determine the quantum efficiency of a cesium fluorescence filter. The fluorescence spectra of cesium atoms are recorded under excitation of the upper states of the second resonance doublet with a Bell-Bloom cesium lamp. Introduction of different noble gases into the cell with cesium leads to the appearance of additional fluorescence photons. It is found that a fluorescence filter based on atomic cesium vapor with addition of helium in the working cell has the highest efficiency and response rate of all known fluorescence filters based on alkali-metal atomic vapors.

  13. Composition-property relationships for radiopaque composite materials: pre-loaded drug-eluting beads for transarterial chemoembolization.

    Science.gov (United States)

    Kilcup, Nancy; Tonkopi, Elena; Abraham, Robert J; Boyd, Daniel; Kehoe, Sharon

    2015-07-01

    The purpose of this study was to synthesize and optimize intrinsically radiopaque composite embolic microspheres for sustained release of doxorubicin in drug-eluting bead transarterial chemoembolization. Using a design of experiments approach, 12 radiopaque composites composed of polylactic-co-glycolic acid and a radiopaque glass (ORP5) were screened over a range of compositions and examined for radiopacity (computed tomography) and density. In vitro cell viability was determined using an extract assay derived from each composition against the human hepatocellular carcinoma cell line, HepG2. Mathematical models based on a D-Optimal response surface methodology were used to determine the preferred radiopaque composite. The resulting radiopaque composite was validated and subsequently loaded with doxorubicin between 0 and 1.4% (wt% of polylactic-co-glycolic acid) to yield radiopaque composite drug-eluting beads. Thereafter, the radiopaque composite drug-eluting beads were subjected to an elution study (up to 168 h) to determine doxorubicin release profiles (UV-Vis spectroscopy) and in vitro cell viability. Radiopaque composites evaluated for screening purposes had densities between 1.28 and 1.67 g.cm(-3), radiopacity ranged between 211 and 1450HU and cell viabilities between 91 and 106% were observed. The optimized radiopaque composite comprised 23 wt% polylactic-co-glycolic acid and 60 wt% ORP5 with a corresponding density of 1.63 ± 0.001 g.cm(-3), radiopacity at 1930 ± 44HU and cell viability of 89 ± 7.6%. Radiopaque composite drug-eluting beads provided sustained doxorubicin release over 168 h. In conclusion, the mathematical models allowed for the identification and synthesis of a unique radiopaque composite. The optimized radiopaque composite had similar density and cell viability to commercially available embolic microspheres. It was possible to preload doxorubicin into radiopaque composite drug-eluting beads, such that sustained release

  14. Kelvin probe studies of cesium telluride photocathode for AWA photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    Wisniewski, Eric E., E-mail: ewisniew@anl.gov [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Velazquez, Daniel [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Yusof, Zikri, E-mail: zyusof@hawk.iit.edu [High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States); Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Spentzouris, Linda; Terry, Jeff [Physics Department, Illinois Institute of Technology, 3300 South Federal Street, Chicago, IL 60616 (United States); Sarkar, Tapash J. [Rice University, 6100 Main, Houston, TX 77005 (United States); Harkay, Katherine [Accelerator Science Division, Argonne National Laboratory, 9700 S. Cass, Lemont, IL 60439 (United States)

    2013-05-21

    Cesium telluride is an important photocathode as an electron source for particle accelerators. It has a relatively high quantum efficiency (>1%), is sufficiently robust in a photoinjector, and has a long lifetime. This photocathode is grown in-house for a new Argonne Wakefield Accelerator (AWA) beamline to produce high charge per bunch (≈50nC) in a long bunch train. Here, we present a study of the work function of cesium telluride photocathode using the Kelvin probe technique. The study includes an investigation of the correlation between the quantum efficiency and the work function, the effect of photocathode aging, the effect of UV exposure on the work function, and the evolution of the work function during and after photocathode rejuvenation via heating. -- Highlights: ► The correlation between Quantum Efficiency (QE) and work function. ► How QE and work function evolve together. ► Rejuvenation of the photocathode via heating and the effect on work function. ► The effects on the work function due to exposure to UV light.

  15. Design alternatives report for the cesium removal demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Walker, J.F. Jr.; Youngblood, E.L.

    1995-09-01

    The Cesium Removal Demonstration (CRD) project will use liquid low-level waste (LLLW) stored in the Oak Ridge National Laboratory Melton Valley Storage Tanks to demonstrate cesium removal from sodium nitrate-based supernates. This report presents the results of a conceptual design study to scope the alternatives for conducting the demonstration at ORNL. Factors considered included (1) sorbent alternatives, (2) facility alternatives, (3) process alternatives, (4) process disposal alternatives, and (5) relative cost comparisons. Recommendations included (1) that design of the CRD system move forward based on information obtained to date from tests with Savannah River Resin, (2) that the CRD system be designed so it could use crystalline silicotitanates (CST) if an engineered form of CST becomes available prior to the CRD, (3) that the system be designed without the capability for resin regeneration, (4) that the LLLW solidification facility be used for the demonstration (5) that vitrification of the loaded resins from the CRD be demonstrated at the Savannah River Site, and (6) that permanent disposal of the loaded and/or vitrified resin at the Nevada Test Site be pursued.

  16. Design alternatives report for the cesium removal demonstration

    International Nuclear Information System (INIS)

    Walker, J.F. Jr.; Youngblood, E.L.

    1995-09-01

    The Cesium Removal Demonstration (CRD) project will use liquid low-level waste (LLLW) stored in the Oak Ridge National Laboratory Melton Valley Storage Tanks to demonstrate cesium removal from sodium nitrate-based supernates. This report presents the results of a conceptual design study to scope the alternatives for conducting the demonstration at ORNL. Factors considered included (1) sorbent alternatives, (2) facility alternatives, (3) process alternatives, (4) process disposal alternatives, and (5) relative cost comparisons. Recommendations included (1) that design of the CRD system move forward based on information obtained to date from tests with Savannah River Resin, (2) that the CRD system be designed so it could use crystalline silicotitanates (CST) if an engineered form of CST becomes available prior to the CRD, (3) that the system be designed without the capability for resin regeneration, (4) that the LLLW solidification facility be used for the demonstration (5) that vitrification of the loaded resins from the CRD be demonstrated at the Savannah River Site, and (6) that permanent disposal of the loaded and/or vitrified resin at the Nevada Test Site be pursued

  17. Lasing in robust cesium lead halide perovskite nanowires

    Science.gov (United States)

    Eaton, Samuel W.; Lai, Minliang; Gibson, Natalie A.; Wong, Andrew B.; Dou, Letian; Ma, Jie; Wang, Lin-Wang; Leone, Stephen R.; Yang, Peidong

    2016-01-01

    The rapidly growing field of nanoscale lasers can be advanced through the discovery of new, tunable light sources. The emission wavelength tunability demonstrated in perovskite materials is an attractive property for nanoscale lasers. Whereas organic–inorganic lead halide perovskite materials are known for their instability, cesium lead halides offer a robust alternative without sacrificing emission tunability or ease of synthesis. Here, we report the low-temperature, solution-phase growth of cesium lead halide nanowires exhibiting low-threshold lasing and high stability. The as-grown nanowires are single crystalline with well-formed facets, and act as high-quality laser cavities. The nanowires display excellent stability while stored and handled under ambient conditions over the course of weeks. Upon optical excitation, Fabry–Pérot lasing occurs in CsPbBr3 nanowires with an onset of 5 μJ cm−2 with the nanowire cavity displaying a maximum quality factor of 1,009 ± 5. Lasing under constant, pulsed excitation can be maintained for over 1 h, the equivalent of 109 excitation cycles, and lasing persists upon exposure to ambient atmosphere. Wavelength tunability in the green and blue regions of the spectrum in conjunction with excellent stability makes these nanowire lasers attractive for device fabrication. PMID:26862172

  18. Everolimus-Eluting Bioresorbable Scaffolds for Coronary Artery Disease.

    Science.gov (United States)

    Ellis, Stephen G; Kereiakes, Dean J; Metzger, D Christopher; Caputo, Ronald P; Rizik, David G; Teirstein, Paul S; Litt, Marc R; Kini, Annapoorna; Kabour, Ameer; Marx, Steven O; Popma, Jeffrey J; McGreevy, Robert; Zhang, Zhen; Simonton, Charles; Stone, Gregg W

    2015-11-12

    In patients with coronary artery disease who receive metallic drug-eluting coronary stents, adverse events such as late target-lesion failure may be related in part to the persistent presence of the metallic stent frame in the coronary-vessel wall. Bioresorbable vascular scaffolds have been developed to attempt to improve long-term outcomes. In this large, multicenter, randomized trial, 2008 patients with stable or unstable angina were randomly assigned in a 2:1 ratio to receive an everolimus-eluting bioresorbable vascular (Absorb) scaffold (1322 patients) or an everolimus-eluting cobalt-chromium (Xience) stent (686 patients). The primary end point, which was tested for both noninferiority (margin, 4.5 percentage points for the risk difference) and superiority, was target-lesion failure (cardiac death, target-vessel myocardial infarction, or ischemia-driven target-lesion revascularization) at 1 year. Target-lesion failure at 1 year occurred in 7.8% of patients in the Absorb group and in 6.1% of patients in the Xience group (difference, 1.7 percentage points; 95% confidence interval, -0.5 to 3.9; P=0.007 for noninferiority and P=0.16 for superiority). There was no significant difference between the Absorb group and the Xience group in rates of cardiac death (0.6% and 0.1%, respectively; P=0.29), target-vessel myocardial infarction (6.0% and 4.6%, respectively; P=0.18), or ischemia-driven target-lesion revascularization (3.0% and 2.5%, respectively; P=0.50). Device thrombosis within 1 year occurred in 1.5% of patients in the Absorb group and in 0.7% of patients in the Xience group (P=0.13). In this large-scale, randomized trial, treatment of noncomplex obstructive coronary artery disease with an everolimus-eluting bioresorbable vascular scaffold, as compared with an everolimus-eluting cobalt-chromium stent, was within the prespecified margin for noninferiority with respect to target-lesion failure at 1 year. (Funded by Abbott Vascular; ABSORB III Clinical

  19. Development of volume reduction method of cesium contaminated soil with magnetic separation

    International Nuclear Information System (INIS)

    Yukumatsu, Kazuki; Nomura, Naoki; Mishima, Fumihito; Akiyama, Yoko; Nishijima, Shigehiro

    2016-01-01

    In this study, we developed a new volume reduction technique for cesium contaminated soil by magnetic separation. Cs in soil is mainly adsorbed on clay which is the smallest particle constituent in the soil, especially on paramagnetic 2:1 type clay minerals which strongly adsorb and fix Cs. Thus selective separation of 2:1 type clay with a superconducting magnet could enable to reduce the volume of Cs contaminated soil. The 2:1 type clay particles exist in various particle sizes in the soil, which leads that magnetic force and Cs adsorption quantity depend on their particle size. Accordingly, we examined magnetic separation conditions for efficient separation of 2:1 type clay considering their particle size distribution. First, the separation rate of 2:1 type clay for each particle size was calculated by particle trajectory simulation, because magnetic separation rate largely depends on the objective size. According to the calculation, 73 and 89 % of 2:1 type clay could be separated at 2 and 7 T, respectively. Moreover we calculated dose reduction rate on the basis of the result of particle trajectory simulation. It was indicated that 17 and 51 % of dose reduction would be possible at 2 and 7 T, respectively. The difference of dose reduction rate at 2 T and 7 T was found to be separated a fine particle. It was shown that magnetic separation considering particle size distribution would contribute to the volume reduction of contaminated soil

  20. Measurements of the cesium flow from a surface-plasma H- ion source

    International Nuclear Information System (INIS)

    Smith, H.V.; Allison, P.W.

    1979-01-01

    A surface ionization gauge (SIG) was constructed and used to measure the Cs 0 flow rate through the emission slit of a surface-plasma source (SPS) of H - ions with Penning geometry. The equivalent cesium density in the SPS discharge is deduced from these flow measurements. For dc operation the optimum H - current occurs at an equivalent cesium density of approx. 7 x 10 12 cm -3 (corresponding to an average cesium consumption rate of 0.5 mg/h). For pulsed operation the optimum H - current occurs at an equivalent cesium density of approx. 2 x 10 13 cm -3 (1-mg/h average cesium consumption rate). Cesium trapping by the SPS discharge was observed for both dc and pulsed operation. A cesium energy of approx. 0.1 eV is deduced from the observed time of flight to the SIG. In addition to providing information on the physics of the source, the SIG is a useful diagnostic tool for source startup and operation

  1. Accumulation and mobility of cesium in roots of tulip popular seedlings

    International Nuclear Information System (INIS)

    Cox, T.L.

    1975-01-01

    Tulip poplar, Liriodendron tulipifera L., seedlings were stem-well tagged with cesium, periodically harvested, and separated into root and shoot compartments to determine seasonal cesium distributions in different root-diameter classes and to delineate element pathways to forest soils. The cesium concentration (μCi/g) in roots less than 0.1 cm in diameter averaged 1.5 and 3.0 times greater than in roots in the 0.5- to 0.1-cm- and 1.0- to 0.5-cm-diameter classes, respectively. Roots contained 24 percent of the seedling pool of cesium in 1 week and about 40 percent in 7 weeks after inoculation. Sixty-five percent of the seedling content was in the root system 8 months after tagging. On an annual basis, roots of the less than 0.5-cm-diameter classes contained an average of 36 percent of the seedling pool (root and shoot) and 72 percent of the root pool of cesium. This is important because small roots constituted a considerable portion of the annual turnover in these root systems. Soil content of cesium (3.37 μCi) at the termination of the study and analysis of treatment effects (aboveground inputs to soil allowed or not allowed) indicated that root processes contributed twice as much cesium to the soil during the study period as the combined aboveground processes contributed

  2. Fast concentration of dissolved forms of cesium radioisotopes from large seawater samples

    International Nuclear Information System (INIS)

    Jan Kamenik; Henrieta Dulaiova; Ferdinand Sebesta; Kamila St'astna; Czech Technical University, Prague

    2013-01-01

    The method developed for cesium concentration from large freshwater samples was tested and adapted for analysis of cesium radionuclides in seawater. Concentration of dissolved forms of cesium in large seawater samples (about 100 L) was performed using composite absorbers AMP-PAN and KNiFC-PAN with ammonium molybdophosphate and potassium–nickel hexacyanoferrate(II) as active components, respectively, and polyacrylonitrile as a binding polymer. A specially designed chromatography column with bed volume (BV) 25 mL allowed fast flow rates of seawater (up to 1,200 BV h -1 ). The recovery yields were determined by ICP-MS analysis of stable cesium added to seawater sample. Both absorbers proved usability for cesium concentration from large seawater samples. KNiFC-PAN material was slightly more effective in cesium concentration from acidified seawater (recovery yield around 93 % for 700 BV h -1 ). This material showed similar efficiency in cesium concentration also from natural seawater. The activity concentrations of 137 Cs determined in seawater from the central Pacific Ocean were 1.5 ± 0.1 and 1.4 ± 0.1 Bq m -3 for an offshore (January 2012) and a coastal (February 2012) locality, respectively, 134 Cs activities were below detection limit ( -3 ). (author)

  3. Zotarolimus-eluting durable-polymer-coated stent versus a biolimus-eluting biodegradable-polymer-coated stent in unselected patients undergoing percutaneous coronary intervention (SORT OUT VI)

    DEFF Research Database (Denmark)

    Raungaard, Bent; Jensen, Lisette Okkels; Tilsted, Hans-Henrik

    2015-01-01

    -polymer zotarolimus-eluting stent or the biodegradable-polymer biolimus-eluting stent. The primary endpoint was a composite of safety (cardiac death and myocardial infarction not clearly attributable to a non-target lesion) and efficacy (target-lesion revascularisation) at 12 months, analysed by intention to treat...

  4. Test procedures and instructions for single shell tank saltcake cesium removal with crystalline silicotitanate

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, J.B.

    1997-01-07

    This document provides specific test procedures and instructions to implement the test plan for the preparation and conduct of a cesium removal test, using Hanford Single Shell Tank Saltcake from tanks 24 t -BY- I 10, 24 1 -U- 108, 24 1 -U- 109, 24 1 -A- I 0 1, and 24 t - S-102, in a bench-scale column. The cesium sorbent to be tested is crystalline siticotitanate. The test plan for which this provides instructions is WHC-SD-RE-TP-024, Hanford Single Shell Tank Saltcake Cesium Removal Test Plan.

  5. Historical Cost Curves for Hydrogen Masers and Cesium Beam Frequency and Timing Standards

    Science.gov (United States)

    Remer, D. S.; Moore, R. C.

    1985-01-01

    Historical cost curves were developed for hydrogen masers and cesium beam standards used for frequency and timing calibration in the Deep Space Network. These curves may be used to calculate the cost of future hydrogen masers or cesium beam standards in either future or current dollars. The cesium beam standards are decreasing in cost by about 2.3% per year since 1966, and hydrogen masers are decreasing by about 0.8% per year since 1978 relative to the National Aeronautics and Space Administration inflation index.

  6. Effects of mineralogy on sorption of strontium and cesium onto Calico Hills Tuff

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Case, F.I.; O'Kelley, G.D.; Land, J.F.

    1990-04-01

    The sorption properties of tuff formations at the proposed site for the high-level nuclear waste repository at Yucca Mountain, Nevada, have been extensively studied. Sorption and desorption measurements were made of strontium and cesium onto clinoptilolite and Calico Hills Tuff. The object was to see whether there was a correlation between sorption of strontium and cesium onto Calico Hills Tuff and the sorption of strontium and cesium onto clinoptilolite based on the content of clinoptilolite in the Calico Hills Tuff. 13 refs., 10 figs., 6 tabs

  7. Advance in the study of removal of cesium from radioactive wastewater by inorganic ion exchangers

    International Nuclear Information System (INIS)

    Wang Songping; Wang Xiaowei; Du Zhihui

    2014-01-01

    The excellent performance in the removal of cesium from radioactive wastewater by inorganic ion exchangers has received extensive attention due to their characteristic physico-chemical features. The paper summarized research progress of removal of cesium by different inorganic ion exchangers such as silicoaluminate, salts of hetero polyacid, hexacyanoferrate, insoluble salts of acid with multivalent metals, insoluble hydrous oxides of multivalent metals and silicotitanate and reviewed several removal systems of cesium by inorganic ion exchangers which might offer China some reference in treatment and disposal of radioactive wastewater. (authors)

  8. First-principles study of cesium adsorption to weathered micaceous clay minerals

    Science.gov (United States)

    Okumura, Masahiko; Nakamura, Hiroki; Machida, Masahiko

    2014-05-01

    A large amount of radioactive nuclides was produced into environment due to the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident. Residents near FDNPP were suffering from radioactive cesium and then evacuated, because which has long half-life and is retained by surface soil for long time. The Japanese government has been decontaminating the cesium by removing the surface soil in order to return them to their home. This decontamination method is very effective, but which produces huge amount of waste soil. This becomes another big problem in Fukushima, because it is not easy to find large storage sites. Then effective and economical methods to reduce the volume of the waste soil are needed. However, it has not been invented yet. One of the reasons is lack of knowledge about microscopic process of adsorption/desorption of cesium to/from soil. It is known that weathered micaceous clay minerals play crucial role on adsorption and retention of cesium. They are expected to have special sorption sites, called frayed edge sites (FESs), which adsorb cesium selectively and irreversibly. Properties of FES have been intensely investigated by experiments. But microscopic details of the adsorption process on FES are still unclear. Because direct observation of the process with current experimental techniques is quite difficult. We investigated the adsorption of cesium to FES in muscovite, which is a typical micaceous clay mineral, via first-principles calculations (density functional theory). We made a minimal model of FES and evaluate the energy difference before and after cesium adsorption to FES. This is the first numerical modeling of FES. It was shown that FES does adsorb cesium if the weathering of muscovite has been weathered. In addition, we revealed the mechanism of cesium adsorption to FES, which is competition between ion radius of cesium and the degree of weathering. I plan to discuss volume reduction of the waste soil based on our result. Reference M. Okumura

  9. Mathematical modeling of cross-linking monomer elution from resin-based dental composites.

    Science.gov (United States)

    Manojlovic, Dragica; Radisic, Marina; Lausevic, Mila; Zivkovic, Slavoljub; Miletic, Vesna

    2013-01-01

    Elution of potentially toxic substances, including monomers, from resin-based dental composites may affect the biocompatibility of these materials in clinical conditions. In addition to the amounts of eluted monomers, mathematical modeling of elution kinetics reveals composite restorations as potential chronic sources of leachable monomers. The aim of this work was to experimentally quantify elution of main cross-linking monomers from four commercial composites and offer a mathematical model of elution kinetics. Composite samples (n = 7 per group) of Filtek Supreme XT (3M ESPE), Tetric EvoCeram (Ivoclar Vivadent), Admira (Voco), and Filtek Z250 (3M ESPE) were prepared in 2-mm thick Teflon moulds and cured with halogen or light-emitting diode light. Monomer elution in ethanol and water was analyzed using high-performance liquid chromatography up to 28 days postimmersion. The mathematical model was expressed as a sum of two exponential regression functions representing the first-order kinetics law. Elution kinetics in all cases followed the same mathematical model though differences in rate constants as well as the extent of monomer elution were material-, LCU-, medium-dependent. The proposed mechanisms of elution indicate fast elution from surface and subsurface layers and up to 100 times slower monomer extraction from the bulk polymer. Copyright © 2012 Wiley Periodicals, Inc.

  10. Biodegradable-Polymer Biolimus-Eluting Stents versus Durable-Polymer Everolimus-Eluting Stents at One-Year Follow-Up: A Registry-Based Cohort Study.

    Science.gov (United States)

    Parsa, Ehsan; Saroukhani, Sepideh; Majlessi, Fereshteh; Poorhosseini, Hamidreza; Lofti-Tokaldany, Masoumeh; Jalali, Arash; Salarifar, Mojtaba; Nematipour, Ebrahim; Alidoosti, Mohammad; Aghajani, Hassan; Amirzadegan, Alireza; Kassaian, Seyed Ebrahim

    2016-04-01

    We compared outcomes of percutaneous coronary intervention patients who received biodegradable-polymer biolimus-eluting stents with those who received durable-polymer everolimus-eluting stents. At Tehran Heart Center, we performed a retrospective analysis of the data from January 2007 through December 2011 on 3,270 consecutive patients with coronary artery disease who underwent percutaneous coronary intervention with the biodegradable-polymer biolimus-eluting stent or the durable-polymer everolimus-eluting stent. We excluded patients with histories of coronary artery bypass grafting or percutaneous coronary intervention, acute ST-segment-elevation myocardial infarction, or the implantation of 2 different stent types. Patients were monitored for 12 months. The primary endpoint was a major adverse cardiac event, defined as a composite of death, nonfatal myocardial infarction, and target-vessel and target-lesion revascularization. Durable-polymer everolimus-eluting stents were implanted in 2,648 (81%) and biodegradable-polymer biolimus-eluting stents in 622 (19%) of the study population. There was no significant difference between the 2 groups (2.7% vs 2.7%; P=0.984) in the incidence of major adverse cardiac events. The cumulative adjusted probability of major adverse cardiac events in the biodegradable-polymer biolimus-eluting stent group did not differ from that of such events in the durable-polymer everolimus-eluting stent group (hazard ratio=0.768; 95% confidence interval, 0.421-1.44; P=0.388). We conclude that in our patients the biodegradable-polymer biolimus-eluting stent was as effective and safe, during the 12-month follow-up period, as was the durable-polymer everolimus-eluting stent.

  11. Radioactive and Stable Cesium Distributions in Fukushima Forests

    Science.gov (United States)

    Ioshchenko, V.; Kivva, S.; Konoplev, A.; Nanba, K.; Onda, Y.; Takase, T.; Zheleznyak, M.

    2015-12-01

    Fukushima Dai-ichi NPP accident has resulted in release into the environment of large amounts of 134Cs and 137Cs and in radioactive contamination of terrestrial and aquatic ecosystems. In Fukushima prefecture up to 2/3 of the most contaminated territory is covered with forests, and understanding of its further fate in the forest ecosystems is essential for elaboration of the long-term forestry strategy. At the early stage, radiocesium was intercepted by the trees' canopies. Numerous studies reported redistribution of the initial fallout in Fukushima forests in the followed period due to litterfall and leaching of radiocesium from the foliage with precipitations. By now these processes have transported the major part of deposited radiocesium to litter and soil compartments. Future levels of radiocesium activities in the aboveground biomass will depend on relative efficiencies of the radiocesium root uptake and its return to the soil surface with litterfall and precipitations. Radiocesium soil-to-plant transfer factors for typical tree species, soil types and landscape conditions of Fukushima prefecture have not been studied well; moreover, they may change in time with approaching to the equilibrium between radioactive and stable cesium isotopes in the ecosystem. The present paper reports the results of several ongoing projects carried out by Institute of Environmental Radioactivity of Fukushima University at the experimental sites in Fukushima prefecture. For typical Japanese cedar (Cryptomeria japonica) forest, we determined distributions of radiocesium in the ecosystem and in the aboveground biomass compartments by the end of 2014; available results for 2015 are presented, too, as well as the results of test application of D-shuttle dosimeters for characterization of seasonal variations of radiocesium activity in wood. Based on the radiocesium activities in biomass we derived the upper estimates of its incorporation and root uptake fluxes, 0.7% and 3% of the total

  12. Comparison of drug-eluting balloon versus drug-eluting stent treatment of drug-eluting stent in-stent restenosis: A meta-analysis of available evidence.

    Science.gov (United States)

    Bajraktari, Gani; Jashari, Haki; Ibrahimi, Pranvera; Alfonso, Fernando; Jashari, Fisnik; Ndrepepa, Gjin; Elezi, Shpend; Henein, Michael Y

    2016-09-01

    In-stent restenosis (ISR) remains an important concern despite the recent advances in the drug-eluting stent (DES) technology. The introduction of drug-eluting balloons (DEB) offers a good solution to such problem. We performed a meta-analysis to assess the clinical efficiency and safety of DEB compared with DES in patients with DES-ISR. A systematic search was conducted and all randomized and observational studies which compared DEB with DES in patients with DES-ISR were included. The primary outcome measure-major adverse cardiovascular events (MACE)-as well as individual events as target lesion revascularization (TLR), stent thrombosis (ST), myocardial infarction (MI), cardiac death (CD) and all-cause mortality, were analyzed. Three randomized and 4 observational studies were included with a total of 2052 patients. MACE (relative risk [RR]=1.00, 95% confidence interval (CI) 0.68 to 1.46, P=0.99), TLR (RR=1.15 [CI 0.79 to 1.68], P=0.44), ST (RR=0.37[0.10 to 1.34], P=0.13), MI (RR=0.97 [0.49 to 1.91], P=0.93) and CD (RR=0.73 [0.22 to 2.45], P=0.61) were not different between patients treated with DEB and with DES. However, all-cause mortality was lower in patients treated with DEB (RR=0.45 [0.23 to 0.87, P=0.019) and in particular when compared to only first generation DES (RR 0.33 [0.15-0.74], P=0.007). There was no statistical evidence for publication bias. The results of this meta-analysis showed that DEB and DES have similar efficacy and safety for the treatment of DES-ISR. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Comparison of the sirolimus-eluting versus paclitaxel-eluting coronary stent in patients with diabetes mellitus: the diabetes and drug-eluting stent (DiabeDES) randomized angiography trial

    DEFF Research Database (Denmark)

    Maeng, Michael; Jensen, Lisette Okkels; Galloe, Anders Michael

    2008-01-01

    The aim of the present study was to evaluate angiographic late luminal loss after the implantation of sirolimus-eluting Cypher stents and paclitaxel-eluting Taxus stents in patients with diabetes. The study was a Danish multicenter, open-label, randomized trial. One hundred fifty-three patients...... stent thrombosis, or target lesion revascularization) were observed in 17 patients (Cypher, n = 6; Taxus, n = 11; p = 0.19). In conclusion, angiographic in-stent late luminal loss is significantly reduced in patients with diabetes by use of the sirolimus-eluting Cypher stent compared with the paclitaxel...

  14. Norbadione A: synthetic approach and cesium complexation studies

    International Nuclear Information System (INIS)

    Desage - El Murr, M.

    2003-10-01

    This work was dedicated to the study of the synthesis and complexation studies of norbadione A: a pigment originating from a mushroom. A synthetic approach, based on a double Suzuki-Miyaura coupling, was developed. This strategy was applied with high yields to the synthesis of various norbadione A analogues, as well as to the synthesis of simple pulvinic acids. Access to functionalized precursors of the molecule was also studied and the final coupling remains to be done. Besides, a speciation study based on electro-spray ionization mass spectrometry was conducted with norbadione A and one of the analogues. This study allowed the assessment of the cesium complexation abilities of each molecule. Structural data was also obtained and complexation constants were calculated. Finally, norbadione A and various synthetic products have been tested via high-throughput screening methods and strong antioxidant properties were observed. Other biological results are also reported. (author)

  15. Decreasing radioactive cesium in lodged buckwheat grain after harvest

    Directory of Open Access Journals (Sweden)

    Katashi Kubo

    2016-01-01

    Full Text Available This study assessed soil contamination with high radioactive cesium (R–Cs concentration in buckwheat grains by lodging, and assessed the possibility of R–Cs reduction in grain through post-harvest preparation. Analysis of buckwheat grain produced in farmers’ fields and reports from farmers indicated that grain from fields that had lodging showed higher R–Cs than grain from fields with no lodging. A field experiment demonstrated that R–Cs in grain after threshing and winnowing (TW was about six times higher in lodged plants than in nonlodged plants. In lodged plants, R–Cs in grain was decreased to about one-fourth by polishing, and was decreased to about one-seventh by ultrasonic cleaning, compared with R–Cs in grain after TW. These results demonstrate that R–Cs of buckwheat grain of lodged plants can be decreased by removing soil from the grain surface by polishing and winnowing.

  16. Quality assurance program plan for cesium legacy project

    International Nuclear Information System (INIS)

    Tanke, J.M.

    1997-01-01

    This Quality Assurance Program Plan (QAPP) provides information on how the Quality Assurance Program is implemented for the Cesium Legacy Project. It applies to those items and tasks which affect the completion of activities identified in the work breakdown structure of the Project Management Plan (PMP). These activities include all aspects of cask transportation, project related operations within the 324 Building, and waste management as it relates to the specific activities of this project. General facility activities (i.e. 324 Building Operations, Central Waste Complex Operations, etc.) are covered in other appropriate QAPPs. The 324 Building is currently transitioning from being a Pacific Northwest National Laboratory (PNNL) managed facility to a B and W Hanford Company (BWHC) managed facility. During this transition process existing PNNL procedures and documents will be utilized until replaced by BWHC procedures and documents

  17. Estimating soil erosion losses in Korea with fallout cesium-137

    International Nuclear Information System (INIS)

    Menzel, R.G.; Pilkyun Jung; Kwanshig Ryu; Kitai Um

    1987-01-01

    The contents of fallout 137 Cs in soil profiles were used to estimate erosion losses from steeply sloping croplands in Korea. Seven undisturbed sites with no apparent erosion or deposition, and 15 cropland sites were examined to a depth of 30 cm. The cropland sites had been cultivated for periods ranging from 5 to more than 80 y (median 10 y), and their slopes ranged from 5 to 26% (median 13%). All except one of the cropland sites contained less 137 Cs than undisturbed sites in the same area. Three cropland sites contained essentially no 137 Cs, indicating erosion of the entire cultivated layer of soil in from 6 to 10 years. Other cropland sites, particularly those with sandy texture, showed little loss of 137 Cs over longer periods of cultivation. Cesium-137 measurements may be useful in identifying site characteristics that reduce the vulnerability of sloping soils to erosion damage. (author)

  18. Cesium-137 accident lessons in Goiania, Goias State, Brazil

    International Nuclear Information System (INIS)

    1990-11-01

    This document relates the experience obtained by several professionals which had an important role in the cesium-137 accident occurred in Goiania, Goias State, Brazil in September, 1987. It's divided into chapters, according to the action area - medical, nursing, social assistance, odontological and psychological. At first, some notions of radioprotection are explained, followed by the accident history and by the doctors and nurses action during the emergency phase and the medical, odontological, social and psychological assistance to the victims. The social assistance report shows some statistical data about the economic, occupational and social conditions of the accident victims. It is shown some information about the health institutions and the sanitary care in the ionizing radiation and about the occupational radiological protection in Goiania

  19. Prompt and delayed excitation and photolysis of cesium dimers

    International Nuclear Information System (INIS)

    Davanloo, F.; Collins, C.B.; Inamdar, A.S.; Mehendale, N.Y.; Nagvi, A.S.

    1984-01-01

    In this work a time-delayed, double resonance technique was used for the study of the state selective photolysis of Cs 2 excited in the yellow range of visible wavelengths. Particular attention being placed on the production of the fine structure components of the 5 2 D and 6 2 P states of Cs and upon the lifetimes of the product populations in the cesium vapor. A quantitative model was constructed to fit the data and rate coefficients were extracted for processes tending to attenuate the product state selectivity. Reported here is what appears to be the first value for the fine-structure mixing cross section for Cs(5 2 D5/2 → 5 2 D 3 /sub 3/2/) of 17 A 2 +-50%, close to the geometric cross section

  20. Electrostatic Focusing of Cesium Atoms in a Fountain

    Science.gov (United States)

    Gould, Harvey; Amini, Jason; Kalnins, Juris

    2004-05-01

    We have used a three element electrostatic lens, based upon the design in Ref. 1, to transversely focus a fountain of neutral cesium atoms (strong-field seeking) launched from a magneto-optic trap. Each of the three lens elements focuses in one transverse direction and defocuses in the other. Combined, the elements generate a net focusing in both transverse directions. Observations are compared with calculations. Collisional shifts in atomic fountain clocks could be significantly reduced, without loss of signal, by using electrostatic lenses and collimation. Focusing and collimation allows only atoms that will reach the detector to enter the interaction region, excluding atoms that contribute solely to collisional shifts. [1] J.G. Kalnins, G. Lambertson, and H. Gould, Rev. Sci. Instr. 73, 2557 (2002)

  1. Cost-Effectiveness Analysis of Infrapopliteal Drug-Eluting Stents

    Energy Technology Data Exchange (ETDEWEB)

    Katsanos, Konstantinos, E-mail: katsanos@med.upatras.gr; Karnabatidis, Dimitris; Diamantopoulos, Athanasios; Spiliopoulos, Stavros; Siablis, Dimitris [Patras University Hospital, Department of Interventional Radiology, School of Medicine (Greece)

    2013-02-15

    IntroductionThere are no cost-utility data about below-the-knee placement of drug-eluting stents. The authors determined the cost-effectiveness of infrapopliteal drug-eluting stents for critical limb ischemia (CLI) treatment. The event-free individual survival outcomes defined by the absence of any major events, including death, major amputation, and target limb repeat procedures, were reconstructed on the basis of two published infrapopliteal series. The first included spot Bail-out use of Sirolimus-eluting stents versus bare metal stents after suboptimal balloon angioplasty (Bail-out SES).The second was full-lesion Primary Everolimus-eluting stenting versus plain balloon angioplasty and bail-out bare metal stenting as necessary (primary EES). The number-needed-to-treat (NNT) to avoid one major event and incremental cost-effectiveness ratios (ICERs) were calculated for a 3-year postprocedural period for both strategies. Overall event-free survival was significantly improved in both strategies (hazard ratio (HR) [confidence interval (CI)]: 0.68 [0.41-1.12] in Bail-out SES and HR [CI]: 0.53 [0.29-0.99] in Primary EES). Event-free survival gain per patient was 0.89 (range, 0.11-3.0) years in Bail-out SES with an NNT of 4.6 (CI: 2.5-25.6) and a corresponding ICER of 6,518 Euro-Sign (range 1,685-10,112 Euro-Sign ). Survival gain was 0.91 (range 0.25-3.0) years in Primary EES with an NNT of 2.7 (CI: 1.7-5.8) and an ICER of 11,581 Euro-Sign (range, 4,945-21,428 Euro-Sign ) per event-free life-year gained. Two-way sensitivity analysis showed that stented lesion length >10 cm and/or DES list price >1000 Euro-Sign were associated with the least economically favorable scenario in both strategies. Both strategies of bail-out SES and primary EES placement in the infrapopliteal arteries for CLI treatment exhibit single-digit NNT and relatively low corresponding ICERs.

  2. Fabrication, characterization and radiation damage stability of hollandite based ceramics devoted to radioactive immobilisation; Synthese, caracterisation et etude du comportement sous irradiation electronique de matrices de type hollandite destinees au confinement du cesium radioactif

    Energy Technology Data Exchange (ETDEWEB)

    Aubin-Chevaldonnet, V. [CEA Valrho, Dir. de l' Energie Nucleaire (DEN/DETCD/SCDV), Dept. d' Etudes du Traitement et du Conditionnement des Dechets, Service de Conditionnement des Dechets et Vitrification, 30 - Marcoule (France)

    2004-11-01

    Research on treating specifically the long-lived and high level nuclear wastes, notably cesium, is currently carried out in France. Cesium immobilization in host matrices of high chemical durability constitutes the favoured option. Hollandite matrix is a good candidate because of its high cesium incorporation ability and its excellent chemical stability. During this study, different compositions of hollandite ceramics Ba{sub x}Cs{sub y}C{sub z}Ti{sub 8-z}O{sub 16} (C = Al{sup 3+}, Cr{sup 3+}, Ga{sup 3+}, Fe{sup 3+}, Mg{sup 2+}, Sc{sup 3+}), synthesized by oxide route, were characterized in terms of structure, microstructure and physical and chemical properties. Iron ions seems to be the most suitable of the studied C cations to get high-performance hollandites. The stability of these ceramics under external electron irradiation, simulating the {beta} particles emitted by radioactive cesium, were also estimated, at the macroscopic and atomic scale. The point defects creation and their thermal stability were followed by electron paramagnetic resonance. (author)

  3. New technique for synthesizing AMP : precipitation inside an ion-exchange resin and its application to separation of cesium from fission-products and to A137sub(m) Ba generator

    International Nuclear Information System (INIS)

    Matsuda, H.T.; Abrao, A.

    1980-06-01

    A new technique for synthesizing ammonium molybdophosphate, an inorganic ion exchanger which retains selectively cesium-137 from a mixture of fission products, is dealt with. Normally the use of this exchanger in column operation requires the use of asbestos, silica-gel or organic polymers as binder, due to its microcrystalline form. The new process employs a strong anionic resin, saturated with molybdate anions. This method enables the precipitation of ammonium molybdophosphate directly into the resinous structure by adding dihydrogen ammonium phosphate in 7,5M HNO 3 . The reactants maintened at 60 0 C for a period of four hours has been found to be the optimum condition for a maximum yield of this compound (anionic resin-ammonium molybdophosphate=R-AMP). The tests performed for characterizing this compound are: molybdenum-phosphorus ratio determination, electronic absorption spectra, infra-red absorption spectra, reflection microscopy observations, electron probe micro-analysis and X-ray powder patterns. The mentioned analysis confirmed the presence of the ammonium molybdophosphate in the resinous structure, permitting, thereby, its use as a cation exchanger. R-AMP showed a capacity of 0,48mE/g of dry material. The cesium retention studies were made using columns charged with R-AMP compound. The behavior of some polivalent fission products was also studied. The R-AMP columns was finally applied to separate cesium from irradiated uranium solutions. A method for the isolation of sup(137m)Ba by successive elutions from R-AMP ( 137 Cs) exchanger (generator) is described. (Author) [pt

  4. Vitrification of cesium-contaminated organic ion exchange resin

    International Nuclear Information System (INIS)

    Sargent, T.N. Jr.

    1994-08-01

    Vitrification has been declared by the Environmental Protection Agency (USEPA) as the Best Demonstrated Available Technology (BDAT) for the permanent disposal of high-level radioactive waste. Savannah River Site currently uses a sodium tetraphenylborate (NaTPB) precipitation process to remove Cs-137 from a wastewater solution created from the processing of nuclear fuel. This process has several disadvantages such as the formation of a benzene waste stream. It has been proposed to replace the precipitation process with an ion exchange process using a new resorcinol-formaldehyde resin developed by Savannah River Technical Center (SRTC). Preliminary tests, however, showed that problems such as crust formation and a reduced final glass wasteform exist when the resin is placed in the melter environment. The newly developed stirred melter could be capable of overcoming these problems. This research explored the operational feasibility of using the stirred tank melter to vitrify an organic ion exchange resin. Preliminary tests included crucible studies to determine the reducing potential of the resin and the extent of oxygen consuming reactions and oxygen transfer tests to approximate the extent of oxygen transfer into the molten glass using an impeller and a combination of the impeller and an external oxygen transfer system. These preliminary studies were used as a basis for the final test which was using the stirred tank melter to vitrify nonradioactive cesium loaded organic ion exchange resin. Results from this test included a cesium mass balance, a characterization of the semi-volatile organic compounds present in the off gas as products of incomplete combustion (PIC), a qualitative analysis of other volatile metals, and observations relating to the effect the resin had on the final redox state of the glass

  5. Beta-decay measurements of neutron-deficient cesium isotopes

    International Nuclear Information System (INIS)

    Parry, R.F.

    1983-03-01

    Beta decay endpoint energy measurements of the neutron deficient cesium isotopes were done using an energy spectrum shape fitting technique. This was a departure from the typical method of endpoint energy analysis, the Fermi-Kurie plot. A discussion of the shape fitting procedure and its improved features are discussed. These beta endpoint measurements have led to total decay energies (Q/sub EC/) of the neutron deficient 119 123 Cs isotopes. The total decay energies of /sup 122m/Cs (Q/sub EC/ = 6.95 +- 0.25 MeV) and 119 Cs (Q/sub EC/ = 6.26 +- 0.29 MeV) were new measurements. The total decay energies of 123 Cs (Q/sub EC/ = 4.05 +- 0.18 MeV), /sup 122g/Cs (Q/sub EC/ = 7.05 +- 0.18 MeV), 121 Cs (Q/sub EC/ = 5.21 +- 0.22 MeV), and 120 Cs (Q/sub EC/ = 7.38 +- 0.23 MeV) were measurements with significantly improved uncertainties as compared to the literature. Further, a combination of the energy levels derived from previous literature gamma-gamma coincident measurements and the experimental beta-coincident gamma decay energies has supported an improved level scheme for 121 Xe and the proposal of three new energy levels in 119 Xe. Comparison of the experimental cesium mass excesses (determined with our Q/sub EC/ values and known xenon mass excesses) with both the literature and theoretical predicted values showed general agreement except for 120 Cs. Possible explanations for this deviation are discussed

  6. Vitrification of cesium-contaminated organic ion exchange resin

    Energy Technology Data Exchange (ETDEWEB)

    Sargent, Jr., Thomas N. [Clemson Univ., SC (United States)

    1994-08-01

    Vitrification has been declared by the Environmental Protection Agency (USEPA) as the Best Demonstrated Available Technology (BDAT) for the permanent disposal of high-level radioactive waste. Savannah River Site currently uses a sodium tetraphenylborate (NaTPB) precipitation process to remove Cs-137 from a wastewater solution created from the processing of nuclear fuel. This process has several disadvantages such as the formation of a benzene waste stream. It has been proposed to replace the precipitation process with an ion exchange process using a new resorcinol-formaldehyde resin developed by Savannah River Technical Center (SRTC). Preliminary tests, however, showed that problems such as crust formation and a reduced final glass wasteform exist when the resin is placed in the melter environment. The newly developed stirred melter could be capable of overcoming these problems. This research explored the operational feasibility of using the stirred tank melter to vitrify an organic ion exchange resin. Preliminary tests included crucible studies to determine the reducing potential of the resin and the extent of oxygen consuming reactions and oxygen transfer tests to approximate the extent of oxygen transfer into the molten glass using an impeller and a combination of the impeller and an external oxygen transfer system. These preliminary studies were used as a basis for the final test which was using the stirred tank melter to vitrify nonradioactive cesium loaded organic ion exchange resin. Results from this test included a cesium mass balance, a characterization of the semi-volatile organic compounds present in the off gas as products of incomplete combustion (PIC), a qualitative analysis of other volatile metals, and observations relating to the effect the resin had on the final redox state of the glass.

  7. Biological effects of cesium-137 injected in beagle dogs of different ages

    International Nuclear Information System (INIS)

    Nikula, K.J.; Muggenburg, B.A.; Griffith, W.C.

    1995-01-01

    The toxicity of cesium-137 ( 137 Cs) in the Beagle dog was investigated at the Argonne National Laboratory (ANL) as part of a program to evaluate the biological effects of internally deposited radionuclides. The toxicity and health effects of 137 Cs are important to understand because 137 Cs is produced in large amounts in light-water nuclear reactors. Large quantities of cesium radioisotopes have entered the human food chain as a result of atmospheric nuclear weapons test, and additional cesium radioisotopes were released during the Chernobyl accident. Although the final analyses are not complete, three findings are significant: older dogs dies significantly earlier than juvenile and young adult dogs; greater occurrence of sarcomas in the cesium-137 injected dogs; the major nonneoplastic effect in dogs surviving beyond 52 d appears to be testicular atrophy

  8. IceBridge Scintrex CS-3 Cesium Magnetometer L0 Raw Magnetic Field

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Scintrex CS-3 Cesium Magnetometer L0 Raw Magnetic Field data set contains magnetic field readings and fluxgate values taken over Greenland using...

  9. Ability of phytoremediation for absorption of strontium and cesium from soils using Cannabis sativa

    Directory of Open Access Journals (Sweden)

    Parisa Seyed Hoseini

    2012-01-01

    Conclusion: Our findings suggest that strontium can be absorbed by Cannabis sativa, with the highest absorption by the roots, stems, and leaves. However, cesium does not reach the plant because of its single capacity and inactive complex formation.

  10. Heat capacity data for selected cesium- and iodine-containing electrolytes in water at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Saluja, P.P.S.; LeBlanc, J.C.

    1985-09-01

    The results of heat capacity measurements are presented for cesium halides and cesium iodate in water at 0.6 MPa and in the temperature range 25 to 100/sup 0/C. Partial molar heat capacity functions, partial molar heat capacity were evaluated by applying Pitzer's ion-interaction model for the extrapolation of calculated apparent molal heat capacity data, phi/sub c/, to infinite dilution. The partial molar heat capacity values in water depend strongly on the cesium salt and the temperature. For all salts, the partial molar heat capacity functions show maxima in the 75 to 93/sup 0/C range. These data can be used to determine various thermodynamic properties of aqueous cesium and iodine systems at elevated temperatures. 27 refs., 7 figs., 11 tabs.

  11. INTERACTIONS BETWEEN CESIUM AND DISPERSED KAOLINITE POWDERS AT HIGH TEMPERATURES FOR TREATMENT OF MIXED WASTES

    Science.gov (United States)

    Kaolinite sorbents were found to manage emissions of vapor phase cesium, when the kaolinite was injected into the combustor, having maximum value between 1400 and 1500 K. The mechanism of this process and its quantification await further research.

  12. Co-precipitation and solubility studies of cesium, potassium and sodium tetraphenylborate

    International Nuclear Information System (INIS)

    Peterson, R.A.

    1999-01-01

    This report contains the results from a study requested by High Level Waste Division on the co-precipitation and solubility of cesium, potassium, and sodium tetraphenylborate. Co-precipitation of cesium (Cs), potassium (K), and sodium (Na) tetraphenylborate (TPB) helps determine the efficiency of reagent usage in the Small Tank Precipitation Process. This process uses NaTPB to remove cesium from waste by means of precipitation. Previous studies by McCabe suggested that if the sodium ion concentration [Na+] increased the rate at which cesium tetraphenylborate (KTPB) in the presence of high [Na+] (∼5M) appears to produce a mixed solid phase composed of NaTPB and KTPB together in the crystal lattice

  13. Efficiency of Dry (Psidium guava) Leaves for The Removal of Cesium-137 from Aqueous Solutions

    International Nuclear Information System (INIS)

    Omar, H.A.; Abu-Kharda, S.A.; Abd El -Baset, L.A.; Abu-Shohba, R.M.

    2012-01-01

    Batch experiments for the removal of cesium-137 from aqueous solution onto guava leaves (psidium guava) and carbonized guava leaves were studied as a function of contact time, dosage, ph value and initial concentration ion. The sorption process was described by pseudo first-order, pseudo second-order, Morris and Elovich kinetic models. Cesium concentrations were ranged between 2x10 -5 - 1x10 -3 M. Sorption data have been interpreted in terms of Langmuir, Freundlich and Dubinin-Radushkevich isotherms. The maximum sorption capacity of carbonized guava leaves adsorbent for cesium removal was 8.02 mgg -1 . The results of the present study suggest that carbonized guava leaves can be used beneficially for cesium removal from aqueous solution.

  14. Next generation extractants for separation of cesium from high-level waste

    International Nuclear Information System (INIS)

    Bartsch, R.A.; Zhou, H.; Delmau, L.H.; Moyer, B.A.

    2008-01-01

    Using calix[4]arene as a scaffold, lipophilic, proton-ionizable ligands for cesium ion extraction have been synthesized. In the 1,3-alternate conformation, lipophilic octyl groups are attached to distal oxygens on one side of the calix[4]arene molecule, and an alkylated benzo-crown-6 unit is connected to distal oxygens on the other side. One phenyl octyl ether unit bears an acidic group in the para-position which orients it directly over the polyether ring. Solvent extractions of trace cesium ion from aqueous solutions into toluene have been performed. The efficiency of cesium ion extraction as a function of the aqueous phase pH and the identity of the acidic group have been assessed. Promising results are obtained for this new series of cesium ion extractants. (authors)

  15. Volatilization characteristics of cesium according to the waste melting method in a plasma torch melter

    International Nuclear Information System (INIS)

    Kim, T. W.; Cho, H. Z.; Park, S. C.; Park, J. K.; Shin, S. W.

    2001-01-01

    By using a batch type plasma torch melting system, melting tests of non-combustible waste were conducted. The relationship between the volatility of cesium and torch power was evaluated. The surrogates used in the tests were natural soil with 0.5 g of non-radioactive cesium (CsCl) per 1 kg of soil. The moisture content of soil was 9.5 wt%. No significant difference in retention ratio (86 ∼ 90 wt%) of cesium in molten slag was founded according to the torch power. The faster melting with high power, the more retentions of cesium into the slag was obtained. Reaching test (TCLP) results for all waste forms were low enough to meet the EPA criteria

  16. Testing Lorentz Invariance with Laser-Cooled Cesium Atomic Frequency Standards

    Science.gov (United States)

    Klipstein, William M.

    2004-01-01

    This slide presentation reviews the Lorentz invariance testing during the proposed PARCS experiment. It includes information on the primary atomic reference clock in space (PARCS), cesium, laser cooling, and the vision for the future.

  17. Investigations of the sorption of cesium from acid solutions by various inorganic sorbents

    International Nuclear Information System (INIS)

    Suess, M.; Pfrepper, G.

    1981-01-01

    Studies have been made to investigate the suitability of various inorganic sorbents for separating and obtaining cesium from acid solutions. In greater details, the distribution coefficients of cesium from nitric acid and ammonium nitrate solution were determined. To determine the saturation capacities it was necessary to plot the isotherms of adsorption from 0.5 N and 3.1 N nitric acid. Experimental sorption from a model solution, of which the composition was equal to that of the liquid Purex waste, enabled the suitability of the various exchangers for obtaining cesium from fission product solutions to be determined. From the results obtained it is apparent that ammonium phosphomolybdate is best suited for obtaining cesium from acid fission product solutions. (orig.)

  18. Total deposition of cesium-137 measured in Finland during the exercise `RESUME 95` in August 1995

    Energy Technology Data Exchange (ETDEWEB)

    Geer, L.E. De; Vintersved, I.; Arntsing, R. [National Defence Research Establisment, Nuclear Detection Group, Stockholm (Sweden)

    1997-12-31

    In the exercise called `RESUME 95` the Nuclear Detection Group from the National Defence Research Establishment in Stockholm participated with field gamma ray measurements combined with soil sampling and profile measurements. The results are presented in this report for the measurements of cesium-137. We considered the measurements of cesium-137 at the airfield the most important part of the in-situ exercise. Data was of course collected also for cesium-134 and natural radionuclides but time has not permitted a full analysis of these radionuclides. The methodology would, however, be the same as applied for cesium-137. Less attention was paid for area II and due to limited personnel resources the search exercise was not fully carried out. (au).

  19. IceBridge Geometrics 823A Cesium Magnetometer L0 Raw Magnetic Field

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Geometrics 823A Cesium Magnetometer L0 Raw Magnetic Field (IMGEO0) data set contains magnetic field readings taken over Antarctica using the...

  20. Studies on the synthesis and characterization of cesium-containing iron phosphate glasses

    Science.gov (United States)

    Joseph, Kitheri; Govindan Kutty, K. V.; Chandramohan, P.; Vasudeva Rao, P. R.

    2009-02-01

    Isotopes of cesium and strontium can be utilized as radiation source for various industrial and medical applications after their separation from high level nuclear waste. However, these elements need to be immobilized in a suitable matrix. In the present work, a systematic approach has been made to immobilize inactive cesium into iron phosphate glass. Up to 36 mol% of Cs 2O has been loaded successfully without crystallization. The glass transition temperature of the cesium loaded glass was found to increase initially and then decrease as a function of Cs 2O content. Mössbauer studies show that the concentration of Fe 3+ ions in the cesium loaded glasses is >95%. Volatilization experiments at 1263 K show that the weight loss is >0.5% for a period of 4 h. The 36 mol% of Cs 2O loaded iron phosphate glass with high Fe 3+ content described in this paper is reported for the first time.

  1. End-of-Life Indicators for NIMA's High-Performance Cesium Frequency Standards

    National Research Council Canada - National Science Library

    Brock, C; Tolman, B. W; Taylor, R. E

    2002-01-01

    .... The mean lifetime of the cesium-beam tube (CBT) is approximately 6 years; failure or end-of-life of the CBT is a significant cause in the reduction of data used to produce the NIMA GPS precise ephemeris...

  2. IceBridge Geometrics 823A Cesium Magnetometer L2 Geolocated Magnetic Anomalies

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Geometrics 823A Cesium Magnetometer L2 Geolocated Magnetic Anomalies (IMGEO2) data set contains magnetic anomaly measurements taken over...

  3. IceBridge Geometrics 823A Cesium Magnetometer L1B Time-Tagged Magnetic Field

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Geometrics 823A Cesium Magnetometer L1B Time-Tagged Magnetic Field (IMGEO1B) data set contains magnetic field strength measurements taken over...

  4. IceBridge Scintrex CS-3 Cesium Magnetometer L1B Geolocated Magnetic Anomalies, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Scintrex CS-3 Cesium Magnetometer L1B Geolocated Magnetic Anomalies (IMCS31B) data set contains magnetic field readings taken over Greenland using...

  5. IceBridge Scintrex CS-3 Cesium Magnetometer L0 Raw Magnetic Field, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Scintrex CS-3 Cesium Magnetometer L0 Raw Magnetic Field data set contains magnetic field readings and fluxgate values taken over Greenland using...

  6. IceBridge Scintrex CS-3 Cesium Magnetometer L1B Geolocated Magnetic Anomalies

    Data.gov (United States)

    National Aeronautics and Space Administration — The NASA IceBridge Scintrex CS-3 Cesium Magnetometer L1B Geolocated Magnetic Anomalies (IMCS31B) data set contains magnetic field readings taken over Antarctica...

  7. Biological effects of cesium-137 injected in beagle dogs of different ages

    Energy Technology Data Exchange (ETDEWEB)

    Nikula, K.J.; Muggenburg, B.A.; Griffith, W.C. [and others

    1995-12-01

    The toxicity of cesium-137 ({sup 137}Cs) in the Beagle dog was investigated at the Argonne National Laboratory (ANL) as part of a program to evaluate the biological effects of internally deposited radionuclides. The toxicity and health effects of {sup 137}Cs are important to understand because {sup 137}Cs is produced in large amounts in light-water nuclear reactors. Large quantities of cesium radioisotopes have entered the human food chain as a result of atmospheric nuclear weapons test, and additional cesium radioisotopes were released during the Chernobyl accident. Although the final analyses are not complete, three findings are significant: older dogs dies significantly earlier than juvenile and young adult dogs; greater occurrence of sarcomas in the cesium-137 injected dogs; the major nonneoplastic effect in dogs surviving beyond 52 d appears to be testicular atrophy.

  8. Safety and efficacy of limus-eluting stents and balloon angioplasty for sirolimus-eluting in-stent restenosis

    Energy Technology Data Exchange (ETDEWEB)

    Ota, Hideaki [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States); Mahmoudi, Michael [University of Surrey, Guildford Road, Surrey, GU2-7XH (United Kingdom); Kitabata, Hironori; Torguson, Rebecca; Chen, Fang; Satler, Lowell F.; Suddath, William O.; Pichard, Augusto D. [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States); Waksman, Ron, E-mail: ron.waksman@medstar.net [Division of Interventional Cardiology, MedStar Washington Hospital Center, Washington, DC 20010 (United States)

    2015-03-15

    Objectives: The aim of this study was to compare the safety and efficacy of everolimus-eluting stent (EES), sirolimus-eluting stent (SES), and plain old balloon angioplasty (POBA) for the treatment of SES in-stent restenosis (S-ISR). Background: The optimal treatment for drug-eluting in-stent restenosis remains controversial. Methods: The study cohort comprised 310 consecutive patients (444 lesions) who presented with S-ISR to our institution and underwent treatment with EES (43 patients), SES (102), or POBA (165). The analyzed clinical parameters were the 1-year rates of death, Q-wave myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), definite stent thrombosis (ST) and major adverse cardiac event (MACE) defined as the composite of death, MI, or TLR at 1-year. Results: The three groups were well matched for the conventional risk factors for coronary artery disease except for smoking. The 1-year analyzed clinical parameters were similar in the three groups: MACE (EES = 14%, SES = 18%, POBA = 20%; p = 0.65), death (EES = 2.3%, SES = 6.2%, POBA = 6.1%; p = 0.61), MI (EES = 4.8%, SES = 2.1%, POBA = 2.5%; p = 0.69), TLR (EES = 11.9%, SES = 12.1%, POBA = 24%; p = 0.78), and TVR (EES = 11.9%, SES = 24.8%, POBA = 22.2%; p = 0.23). There were no cases of definite ST. MACE-free rate was significantly lower in patients with recurrent in-stent restenosis (log-rank p = 0.006). Presentation with acute MI, number of treated lesions and a previous history of MI were found to be independent predictors of MACE. Conclusions: In patients presenting with S-ISR, treatment with implantation of an EES, SES, or POBA is associated with similar clinical outcomes. Patients presenting with recurrent ISR may have a poorer clinical outcome.

  9. Demonstration of fly-ash filter for trapping volatile radioactive cesium in off-gas stream

    International Nuclear Information System (INIS)

    Chun, K. S.; Park, J. J.; Shon, J. S.; Shin, J. M.; Choi, K. W.

    2000-02-01

    The object of this study is to design and operate the fly ash filter unit for trapping cesium in the vitrification pilot process of radioactive waste in the low and medium level. It is necessary to reuse fly ash, which is a kind of waste from coal fired power plant, in trapping cesium generated from vitrification process and improving safety and removal efficiency of off gas treatment system. According to the XRD analysis on the trapping cesium compounds by the fly ash filter, the thermally stable pollucite phase was formed when the SO x or NO x was used as the carrier gas. The trapping efficiency of volatile cesium by the fly ash filter was decreased with the increase of face velocity, whereas the efficiency was increased with the increase of the reaction temperature. And also, by increasing the reaction time, the efficiency was decreased. The trapping efficiency of volatile cesium by the fly ash filter was higher than 99.5 percent under the air or NO x /air as a carrier gas, however, the efficiency was decreased to 99.0 percent under the NO x /N 2 as a carrier gas. By the way, the effect of NO x in the vitrification pilot process might be negligible due to the supply of the significant amount of oxygen. However, because using the SO x as the carrier gas the efficiency was slightly decreased to 93.5 percent, the influence of the SO x on the trapping cesium by the fly ash filter seems to be concerned in that pilot process. The fly ash filter unit was performed in the vitrification pilot process, but the trapping efficiency of cesium by that filter could not measured because analytical instruments can not detect the cesium. However, it is confirmed that the the stainless steel 310 can be used for the material of filter frame and housing and shows the corrosion resistance at high temperature (1000 deg C). (author)

  10. Modelling of the earth atmosphere contamination as result of cesium 137 deflation from contaminated territories

    International Nuclear Information System (INIS)

    Zhmura, G.M.; Zhmura, N.V.

    1998-01-01

    The results of calculation of cesium 137 average annual ground atmosphere concentrations on the Belarus territory in the knots of net (50*50) km are given. The calculations were made on the base of a model notions about dusting area sources. Analysis of the results shows that cesium 137 average annual ground atmosphere concentrations on the Belarus territory are varied more than two orders depending on a point of calculation from 1 to 400 micro Bq/m 3

  11. Contribution of the pectin in the cesium elimination in organism. results of analysis on Belarus children

    International Nuclear Information System (INIS)

    2007-01-01

    The results make appear that the cesium 137 would be eliminated less quick than what the ICRP considered for its models. Pectin would accelerate the cesium elimination but less quick than what is announced by its promotors. Politically speaking, the pectin is ignored by the officials of medicine and radiation protection at the pretext that its efficiency is not proved but no study is made. (N.C.)

  12. Size distribution of DNA molecules recovered from non-denaturing filter elution

    International Nuclear Information System (INIS)

    Bloecher, D.; Iliakis, G.

    1991-01-01

    DNA fragments removed from the filter during non-denaturing filter elution were collected and loaded on top of neutral sucrose gradients. Their size distribution was determined by low-speed centrifugation in neutral sucrose gradients. The average size of eluted DNA was found to be approximately 110 S; the average size of DNA collected after short elution times was found to be slightly larger than after long elution times. It is concluded that the size of eluted DNA fragments is not correlated with elution rate, and it is proposed that shear forces generated at the filter pores cause degradation of the DNA. Comparison of sedimentation profiles of carefully prepared cellular DNA before and after elution revealed that generated shear forces during elution break down DNA to an extent equivalent to around 20 000 DNA double-strand breaks (dsb) per G 1 cell. The size of DNA fragments decreased with increasing radiation dose; five times more dsb were found than expected after exposure to radiation alone. It is proposed that excess of dsb may derive from the transformation of other radiation-induced lesions to dsb under the action of shear forces generated during elution. (author)

  13. Drug-Eluting Fibers for HIV-1 Inhibition and Contraception

    Science.gov (United States)

    Ball, Cameron; Krogstad, Emily; Chaowanachan, Thanyanan; Woodrow, Kim A.

    2012-01-01

    Multipurpose prevention technologies (MPTs) that simultaneously prevent sexually transmitted infections (STIs) and unintended pregnancy are a global health priority. Combining chemical and physical barriers offers the greatest potential to design effective MPTs, but integrating both functional modalities into a single device has been challenging. Here we show that drug-eluting fiber meshes designed for topical drug delivery can function as a combination chemical and physical barrier MPT. Using FDA-approved polymers, we fabricated nanofiber meshes with tunable fiber size and controlled degradation kinetics that facilitate simultaneous release of multiple agents against HIV-1, HSV-2, and sperm. We observed that drug-loaded meshes inhibited HIV-1 infection in vitro and physically obstructed sperm penetration. Furthermore, we report on a previously unknown activity of glycerol monolaurate (GML) to potently inhibit sperm motility and viability. The application of drug-eluting nanofibers for HIV-1 prevention and sperm inhibition may serve as an innovative platform technology for drug delivery to the lower female reproductive tract. PMID:23209601

  14. Elution of monomer from different bulk fill dental composite resins.

    Science.gov (United States)

    Cebe, Mehmet Ata; Cebe, Fatma; Cengiz, Mehmet Fatih; Cetin, Ali Rıza; Arpag, Osman Fatih; Ozturk, Bora

    2015-07-01

    The purpose of this study was to evaluate the elution of Bis-GMA, TEGDMA, HEMA, and Bis-EMA monomers from six bulk fill composite resins over four different time periods, using HPLC. Six different composite resin materials were used in the present study: Tetric Evo Ceram Bulk Fill (Ivoclar Vivadent, Amherst, NY), X-tra Fill (VOCO, Cuxhaven, Germany), Sonic Fill (Kerr, Orange, CA, USA), Filtek Bulk Fill (3M ESPE Dental Product, St. Paul, MN), SDR (Dentsply, Konstanz, Germany), EQUIA (GC America INC, Alsip, IL). The samples (4mm thickness, 5mm diameter) were prepared and polymerized for 20s with a light emitted diode unit. After fabrication, each sample was immediately immersed in 75wt% ethanol/water solution used as extraction fluid and stored in the amber colored bottles at room temperature. Ethanol/water samples were taken (0.5mL) at predefined time intervals:10m (T1), 1h (T2), 24h (T3) and 30 days (T4). These samples were analyzed by HPLC. The obtained data were analyzed with one-way ANOVA and Tukey HSD at significance level of pcomposites (pcomposite resins in all time periods and the amount of eluted monomers was increased with time. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. Drug-eluting fibers for HIV-1 inhibition and contraception.

    Directory of Open Access Journals (Sweden)

    Cameron Ball

    Full Text Available Multipurpose prevention technologies (MPTs that simultaneously prevent sexually transmitted infections (STIs and unintended pregnancy are a global health priority. Combining chemical and physical barriers offers the greatest potential to design effective MPTs, but integrating both functional modalities into a single device has been challenging. Here we show that drug-eluting fiber meshes designed for topical drug delivery can function as a combination chemical and physical barrier MPT. Using FDA-approved polymers, we fabricated nanofiber meshes with tunable fiber size and controlled degradation kinetics that facilitate simultaneous release of multiple agents against HIV-1, HSV-2, and sperm. We observed that drug-loaded meshes inhibited HIV-1 infection in vitro and physically obstructed sperm penetration. Furthermore, we report on a previously unknown activity of glycerol monolaurate (GML to potently inhibit sperm motility and viability. The application of drug-eluting nanofibers for HIV-1 prevention and sperm inhibition may serve as an innovative platform technology for drug delivery to the lower female reproductive tract.

  16. Dynamics of silver elution from functionalised antimicrobial nanofiltration membranes.

    Science.gov (United States)

    Choudhari, S; Habimana, O; Hannon, J; Allen, A; Cummins, E; Casey, E

    2017-07-01

    In an effort to mitigate biofouling on thin film composite membranes such as nanofiltration and reverse osmosis, a myriad of different surface modification strategies has been published. The use of silver nanoparticles (Ag-NPs) has emerged as being particularly promising. Nevertheless, the stability of these surface modifications is still poorly understood, particularly under permeate flux conditions. Leaching or elution of Ag-NPs from the membrane surface can not only affect the antimicrobial characteristics of the membrane, but could also potentially present an environmental liability when applied in industrial-scale systems. This study sought to investigate the dynamics of silver elution and the bactericidal effect of an Ag-NP functionalised NF270 membrane. Inductively coupled plasma-atomic emission spectroscopy was used to show that the bulk of leached silver occurred at the start of experimental runs, and was found to be independent of salt or permeate conditions used. Cumulative amounts of leached silver did, however, stabilise following the initial release, and were shown to have maintained the biocidal characteristics of the modified membrane, as observed by a higher fraction of structurally damaged Pseudomonas fluorescens cells. These results highlight the need to comprehensively assess the time-dependent nature of bactericidal membranes.

  17. Drug Release Analysis and Optimization for Drug-Eluting Stents

    Directory of Open Access Journals (Sweden)

    Hongxia Li

    2013-01-01

    Full Text Available The drug release analysis and optimization for drug-eluting stents in the arterial wall are studied, which involves mechanics, fluid dynamics, and mass transfer processes and design optimization. The Finite Element Method (FEM is used to analyze the process of drug release in the vessels for drug-eluting stents (DES. Kriging surrogate model is used to build an approximate function relationship between the drug distribution and the coating parameters, replacing the expensive FEM reanalysis of drug release for DES in the optimization process. The diffusion coefficients and the coating thickness are selected as design variables. An adaptive optimization approach based on kriging surrogate model is proposed to optimize the lifetime of the drug in artery wall. The adaptive process is implemented by an infilling sampling criterion named Expected Improvement (EI, which is used to balance local and global search and tends to find the global optimal design. The effect of coating diffusivity and thickness on the drug release process for a typical DES is analyzed by means of FEM. An implementation of the optimization method for the drug release is then discussed. The results demonstrate that the optimized design can efficiently improve the efficacy of drug deposition and penetration into the arterial walls.

  18. Advantages and disadvantages of biodegradable platforms in drug eluting stents.

    Science.gov (United States)

    Rodriguez-Granillo, Agustina; Rubilar, Bibiana; Rodriguez-Granillo, Gaston; Rodriguez, Alfredo E

    2011-03-26

    Coronary angioplasty with drug-eluting stent (DES) implantation is currently the most common stent procedure worldwide. Since the introduction of DES, coronary restenosis as well as the incidence of target vessel and target lesion revascularization have been significantly reduced. However, the incidence of very late stent thrombosis beyond the first year after stent deployment has more commonly been linked to DES than to bare-metal stent (BMS) implantation. Several factors have been associated with very late stent thrombosis after DES implantation, such as delayed healing, inflammation, stent mal-apposition and endothelial dysfunction. Some of these adverse events were associated with the presence of durable polymers, which were essential to allow the elution of the immunosuppressive drug in the first DES designs. The introduction of erodable polymers in DES technology has provided the potential to complete the degradation of the polymer simultaneously or immediately after the release of the immunosuppressive drug, after which a BMS remains in place. Several DES designs with biodegradable (BIO) polymers have been introduced in preclinical and clinical studies, including randomized trials. In this review, we analyze the clinical results from 6 observational and randomized studies with BIO polymers and discuss advantages and disadvantages of this new technology.

  19. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J

    2012-01-01

    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used....

  20. Experimental and analytical study on cesium iodide behavior in piping in wave experiment

    Energy Technology Data Exchange (ETDEWEB)

    Hidaka, A.; Igarashi, M.; Hashimoto, K.; Sugimoto, J. [Japan Atomic Energy Research Inst., Dep. of Reactor Safety Research, Tokai-mura (Japan); Yoshino, T. [Toshiba Advanced System Corp., Isago Kawasaki-ku (Japan)

    1996-12-01

    The WAVE (Wide range Aerosol model VErification) experiments have been performed at JAERI to investigate cesium iodide (CsI) deposition onto an inner surface of piping wall under typical severe accident conditions. The test facility consists of a dish containing CsI powder, electrical heaters and a straight pipe of 1.5 m in length with diameter of 0.042m. Nitrogen gas and superheated steam were injected into the pipe to carry the vaporized CsI and to simulate the thermohydraulic condition for the PWR hot-leg inlet. Analyses of the experiments have been conducted with a three-dimensional thermohydraulic code, SPRAC and the radionuclide behavior analysis codes, ART and VICTORIA. A clear difference was found in the deposition behavior between nitrogen and steam conditions as carrier gases. For nitrogen gas, the analyses well reproduced the experimental results by closely coupling the CsI behavior and the detailed thermohydraulic analyses. For steam carrier gas, on the contrary, the experimental results could not be well reproduced without the use of larger aerosol size. Since the observed enhancement of aerosol size in superheated steam cannot be explained by existing models, it is necessary to further investigate this mechanisms by experiment and analysis. (author) 34 figs., 23 refs.

  1. Water-Mediated Differential Binding of Strontium and Cesium Cations in Fulvic Acid.

    Science.gov (United States)

    Sadhu, Biswajit; Sundararajan, Mahesh; Bandyopadhyay, Tusar

    2015-08-27

    The migration of potentially harmful radionuclides, such as cesium ((137)Cs) and strontium ((90)Sr), in soil is governed by the chemical and biological reactivity of soil components. Soil organic matter (SOM) that can be modeled through fulvic acid (FA) is known to alter the mobility of radionuclide cations, Cs(+) and Sr(2+). Shedding light on the possible interaction mechanisms at the atomic level of these two ions with FA is thus vital to explain their transport behavior and for the design of new ligands for the efficient extraction of radionuclides. Here we have performed molecular dynamics, metadynamics simulations, and density-functional-theory-based calculations to understand the binding mechanism of Sr(2+) and Cs(+) cations with FA. Our studies predict that interaction of Cs(+) to FA is very weak as compared with Sr(2+). While the water-FA interaction is largely responsible for the weak binding of Cs(+) to FA, leading to the outer sphere complexation of the ion with FA, the interaction between Sr(2+) and FA is stronger and thus can surpass the existing secondary nonbonding interaction between coordinated waters and FA, leading to inner sphere complexation of the ion with FA. We also find that entropy plays a dominant role for Cs(+) binding to FA, whereas Sr(2+) binding is an enthalpy-driven process. Our predicted results are found to be in excellent agreement with the available experimental data on complexation of Cs(+) and Sr(2+) with SOM.

  2. MODELING CST ION EXCHANGE FOR CESIUM REMOVAL FROM SCIX BATCHES 1 - 4

    Energy Technology Data Exchange (ETDEWEB)

    Smith, F.

    2011-04-25

    The objective of this work is, through modeling, to predict the performance of Crystalline Silicotitinate (CST) for the removal of cesium from Small Column Ion Exchange (SCIX) Batches 1-4 (as proposed in Revision 16 of the Liquid Waste System Plan). The scope of this task is specified in Technical Task Request (TTR) 'SCIX Feed Modeling', HLE-TTR-2011-003, which specified using the Zheng, Anthony, Miller (ZAM) code to predict CST isotherms for six given SCIX feed compositions and the VErsatile Reaction and SEparation simulator for Liquid Chromatography (VERSE-LC) code to predict ion-exchange column behavior. The six SCIX feed compositions provided in the TTR represent SCIX Batches 1-4 and Batches 1 and 2 without caustic addition. The study also investigated the sensitivity in column performance to: (1) Flow rates of 5, 10, and 20 gpm with 10 gpm as the nominal flow; and (2) Temperatures of 25, 35, and 45 C with 35 C as the nominal temperature. The isotherms and column predictions presented in this report reflect the expected performance of engineered CST IE-911. This form of CST was used in experiments conducted at the Savannah River National Laboratory (SRNL) that formed the basis for estimating model parameters (Hamm et al., 2002). As has been done previously, the engineered resin capacity is estimated to be 68% of the capacity of particulate CST without binder.

  3. Competitive adsorption of cesium, cobalt and strontium in conditioned clayey soil suspensions

    International Nuclear Information System (INIS)

    Gutierrez, M.; Fuentes, H.R.; Texas Univ., El Paso, TX

    1991-01-01

    Competitive adsorption of the ions (solutes) cesium, cobalt and strontium by soil samples from Hudspeth County, Texas, was investigated in laboratory experiments. Binary and ternary mixtures containing same weight percentage of each ion were placed in contact with the soil, at constant soil:solution ratio, temperature and pressure, until equilibrium was reached. Once it was determined that the adsorption of single adsorbates was well represented by the Freundlich equation, the Sheindorf-Rehbun-Sheintuck (SRS) equation was used to obtain the competitive coefficients for each component of the binary mixtures. The SRS-equation for ternary mixtures predicts the adsorption of each ion based on the parameters of its respective single-analog isotherm and the competitive coefficients obtained for binary mixtures. Predicted values were very close to those obtained experimentally for ternary mixtures. Competition coefficients vary from 0.15 to 0.20 for cobalt in the presence of strontium and 1.0 to 1.3 in the presence of cesium: 0.3 to 0.6 for cesium in the presence of strontium and 0.4 to 0.8 in the presence of cobalt; 3.0 to 6.3 for strontium in the presence of cesium, and 4.5 in the presence of cobalt. These values suggest heterogeneous interactions between ions and adsorption sites: cobalt and cesium do not compete for adsorption sites as much as cobalt does with strontium, or cesium with strontium. (author)

  4. Concentrating cesium-137 from seawater using resorcinol-formaldehyde resin for radioecological monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Egorin, Andrei; Tokar, Eduard; Tutov, Mikhail; Avramenko, Valentin [Institute of Chemistry FEBRAS, Vladivostok (Russian Federation); Far Eastern Federal Univ., Vladivostok (Russian Federation); Palamarchuk, Marina; Marinin, Dmitry [Institute of Chemistry FEBRAS, Vladivostok (Russian Federation)

    2017-04-01

    A method of preconcentrating cesium-137 from seawater using a resorcinol-formaldehyde resin, which enables one to optimize the ecological monitoring procedure, has been suggested. Studies of sorption of cesium-137 from seawater by resorcinol-formaldehyde resin have been performed, and it has been demonstrated that the cation exchanger is characterized by high selectivity with respect to cesium-137. It was found that the selectivity depended on the temperature of resin solidification and the seawater pH value. The maximal value of the cesium-137 distribution coefficient is equal to 4.1-4.5 x 10{sup 3} cm{sup 3} g{sup -1}. Under dynamic conditions, the ion-exchange resin capacity is 310-910 bed volumes depending on the seawater pH, whereas the efficiency of cesium removal exceeds 95%. The removal of more than 95% of cesium-137 has been attained using 1-3 M solutions of nitric acid: here, the eluate volume was 8-8.4 bed volumes. Application of 3 M solution of nitric acid results in resin degradation with the release of gaseous products.

  5. Crystalline silicotitanates--new ion exchanger for selective removal of cesium and strontium from radwastes

    International Nuclear Information System (INIS)

    Dosch, R.G.; Klavetter, E.A.; Stephens, H.P.; Brown, N.E.; Anthony, R.G.

    1996-08-01

    A new class of inorganic ion exchange material called crystalline silicotitanates (CST) has been developed for radioactive waste treatment in a collaborative effort between Sandia National Laboratories and Texas A ampersand M University. The Sandia National Laboratories Laboratory Directed Research and Development program provided the initial funding for this effort and this report summarizes the rapid progress that was achieved. A wide range of compositions were synthesized, evaluated for cesium (Cs) removal efficiency, and a composition called TAM-5 was developed that exhibits high selectivity and affinity for Cs and strontium (Sr). Tests show it can remove parts per million concentrations of Cs + from highly alkaline, high-sodium, simulated radioactive waste solutions modeled after those at Hanford, Oak Ridge, and Savannah River. In experiments with solutions that simulate highly alkaline Hanford defense wastes, the crystalline silicotitanates exhibit distribution coefficients for Cs + of greater than 2,000 ml/g, and distribution coefficients greater than 10,000 ml/g for solutions adjusted to a pH between 1 and 10. In addition, the CSTs were found to exhibit distribution coefficients for Sr + greater than 100,000 ml/g and for plutonium of 2,000 ml/g from simulated Hanford waste. The CST crystal structure was determined and positions of individual atoms identified using x-ray and neutron diffraction. The structural information has permitted identification of the ion exchange sites and provided insights into the strong effect of pH on Cs ion exchange. Information on the synthesis, composition, and structure of CST is considered proprietary and is not discussed in this report

  6. Alkaline-Side Extraction of Cesium from Savannah River Tank Waste Using a Calixarene-Crown Ether Extractant

    Energy Technology Data Exchange (ETDEWEB)

    Bonnesen, P.V.; Delmau, L.H.; Haverlock, T.J.; Moyer, B.A.

    1998-12-01

    Results are presented supporting the viability of the alkaline-side CSEX process as a potential replacement for the In-Tank Precipitation process for removal of cesium from aqueous high-level waste (HLW) at the Savannah River Site (SRS). Under funding from the USDOE Efficient Separations and Crosscutting program, a flowsheet was suggested in early June of 1998, and in the following four months, this flowsheet underwent extensive testing, both in batch tests at ORNL and ANL and in two centrifugal-contactor tests at ANL. To carry out these tests, the initial ESP funding was augmented by direct funds from Westinghouse Savannah River Corporation. The flowsheet employed a solvent containing a calixarene-crown hybrid compound called BoBCalixC6 that was invented at ORNL and can now be obtained commercially for government use from IBC Advanced Technologies. This special extractant is so powerful and selective that it can be used at only 0.01 M, compensating for its expense, but a modifier is required for use in an aliphatic diluent, primarily to increase the cesium distribution ratio D{sub Cs} in extraction. The modifier selected is a relatively economical fluorinated alcohol called Cs3, invented at ORNL and so far available. only from ORNL. For the flowsheet, the modifier is used at 0.2 M in the branched aliphatic kerosene Isopar{reg_sign} L. Testing at ORNL and ANL involved simulants of the SRS HLW. After extraction of the Cs from the waste simulant, the solvent is scrubbed with 0.05 M HNO{sub 3} and stripped with a solution comprised of 0.0005 M HNO{sub 3} and 0.0001 M CsNO{sub 3}. The selection of these conditions is justified in this report, both on the basis of experimental data and underlying theory.

  7. Effects of experimental parameters on the sorption of cesium, strontium, and uranium from saline groundwaters onto shales: Progress report

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Case, F.I.; O'Kelley, G.D.

    1988-11-01

    This report concerns an extension of the first series of experiments on the sorption properties of shales and their clay mineral components reported earlier. Studies on the sorption of cesium and strontium were carried out on samples of Chattanooga (Upper Dowelltown), Pierre, Green River Formation, Nolichucky, and Pumpkin Valley Shales that had been heated to 120/degree/C in a 0.1-mol/L NaCl solution for periods up to several months and on samples of the same shales which had been heated to 250/degree/C in air for six months, to simulate limiting scenarios in a HLW repository. To investigate the kinetics of the sorption process in shale/groundwater systems, strontium sorption experiments were done on unheated Pierre, Green River Formation, Nolichucky, and Pumpkin Valley Shales in a diluted, saline groundwater and in 0.03-mol/L NaHCO 3 , for periods of 0.25 to 28 days. Cesium sorption kinetics tests were performed on the same shales in a concentrated brine for the same time periods. The effect of the water/rock (W/R) ratio on sorption for the same combinations of unheated shales, nuclides, and groundwaters used in the kinetics experiments was investigated for a range of W/R ratios of 3 to 20 mL/g. Because of the complexity of the shale/groundwater interaction, a series of tests was conducted on the effects of contact time and W/R ratio on the pH of a 0.03-mol/L NaHCO 3 simulated groundwater in contact with shales. 8 refs., 12 figs., 15 tabs

  8. Determinants of protein elution rates from preparative ion-exchange adsorbents.

    Science.gov (United States)

    Angelo, James M; Lenhoff, Abraham M

    2016-04-01

    The rate processes involved in elution in preparative chromatography can affect both peak resolution and hence selectivity as well as practical factors such as facility fit. These processes depend on the physical structure of the adsorbent particles, the amount of bound solute, the solution conditions for operation or some combination of these factors. Ion-exchange adsorbents modified with covalently attached or grafted polymer layers have become widely used in preparative chromatography. Their often easily accessible microstructures offer substantial binding capacities for biomolecules, but elution has sometimes been observed to be undesirably slow. In order to determine which physicochemical phenomena control elution behavior, commercially available cellulosic, dextran-grafted and unmodified agarose materials were characterized here by their elution profiles at various conditions, including different degrees of loading. Elution data were analyzed under the assumption of purely diffusion-limited control, including the role of pore structure properties such as porosity and tortuosity. In general, effective elution rates decreased with the reduction of accessible pore volume, but differences among different proteins indicated the roles of additional factors. Additional measurements and analysis, including the use of confocal laser scanning microscopy to observe elution within single chromatographic particles, indicated the importance of protein association within the particle during elution. The use of protein stabilizing agents was explored in systems presenting atypical elution behavior, and l-arginine and disaccharide excipients were shown to alleviate the effects for one protein, lysozyme, in the presence of sodium chloride. Incorporation of these excipients into eluent buffer gave rise to faster elution and significantly lower pool volumes in elution from polymer-modified adsorbents. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Simulation

    CERN Document Server

    Ross, Sheldon

    2006-01-01

    Ross's Simulation, Fourth Edition introduces aspiring and practicing actuaries, engineers, computer scientists and others to the practical aspects of constructing computerized simulation studies to analyze and interpret real phenomena. Readers learn to apply results of these analyses to problems in a wide variety of fields to obtain effective, accurate solutions and make predictions about future outcomes. This text explains how a computer can be used to generate random numbers, and how to use these random numbers to generate the behavior of a stochastic model over time. It presents the statist

  10. Ultrathin, bioresorbable polymer sirolimus-eluting stents versus thin, durable polymer everolimus-eluting stents in patients undergoing coronary revascularisation (BIOFLOW V): a randomised trial.

    Science.gov (United States)

    Kandzari, David E; Mauri, Laura; Koolen, Jacques J; Massaro, Joseph M; Doros, Gheorghe; Garcia-Garcia, Hector M; Bennett, Johan; Roguin, Ariel; Gharib, Elie G; Cutlip, Donald E; Waksman, Ron

    2017-10-21

    The development of coronary drug-eluting stents has included use of new metal alloys, changes in stent architecture, and use of bioresorbable polymers. Whether these advancements improve clinical safety and efficacy has not been shown in previous randomised trials. We aimed to examine the clinical outcomes of a bioresorbable polymer sirolimus-eluting stent compared with a durable polymer everolimus-eluting stent in a broad patient population undergoing percutaneous coronary intervention. BIOFLOW V was an international, randomised trial done in patients undergoing elective and urgent percutaneous coronary intervention in 90 hospitals in 13 countries (Australia, Belgium, Canada, Denmark, Germany, Hungary, Israel, the Netherlands, New Zealand, South Korea, Spain, Switzerland, and the USA). Eligible patients were those aged 18 years or older with ischaemic heart disease undergoing planned stent implantation in de-novo, native coronary lesions. Patients were randomly assigned (2:1) to either an ultrathin strut (60 μm) bioresorbable polymer sirolimus-eluting stent or to a durable polymer everolimus-eluting stent. Randomisation was via a central web-based data capture system (mixed blocks of 3 and 6), and stratified by study site. The primary endpoint was 12-month target lesion failure. The primary non-inferiority comparison combined these data from two additional randomised trials of bioresorbable polymer sirolimus-eluting stent and durable polymer everolimus-eluting stent with Bayesian methods. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT02389946. Between May 8, 2015, and March 31, 2016, 4772 patients were recruited into the study. 1334 patients met inclusion criteria and were randomly assigned to treatment with bioresorbable polymer sirolimus-eluting stents (n=884) or durable polymer everolimus-eluting stents (n=450). 52 (6%) of 883 patients in the bioresorbable polymer sirolimus-eluting stent group and 41 (10%) of

  11. 2-year clinical outcomes after implantation of sirolimus-eluting, paclitaxel-eluting, and bare-metal coronary stents: results from the WDHR (Western Denmark Heart Registry)

    DEFF Research Database (Denmark)

    Kaltoft, Anne; Jensen, Lisette Okkels; Maeng, Michael

    2009-01-01

    OBJECTIVES: This registry study assessed the safety and efficacy of the 2 types of drug-eluting stents (DES), sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES), compared with bare-metal stents (BMS). BACKGROUND: Drug-eluting stents may increase the risk of stent thrombosis (ST...... databases. We used Cox regression analysis to control for confounding. RESULTS: The 2-year incidence of definite ST was 0.64% in BMS patients, 0.79% in DES patients (adjusted relative risk [RR]: 1.09; 95% confidence interval [CI]: 0.72 to 1.65), 0.50% in SES patients (adjusted RR: 0.63, 95% CI: 0.35 to 1...

  12. Formation, decomposition and cesium adsorption mechanisms of highly alkali-tolerant nickel ferrocyanide prepared by interfacial synthesis

    International Nuclear Information System (INIS)

    Ichikawa, Tsuneki; Yamada, Kazuo; Osako, Masahiro; Haga, Kazuko

    2017-01-01

    Highly alkali-tolerant nickel ferrocyanide was prepared as an adsorbent for preventing the leaching of radioactive cesium from municipal solid waste incinerator fly ash containing large amounts of calcium hydroxide and potassium chloride, which act as an alkaline source and the suppressor for cesium adsorption, respectively. Nickel ferrocyanide prepared by contacting concentrated nickel and ferrocyanide solutions without mixing adsorbed cesium ions in alkaline conditions even the concentration of coexisting potassium ions was more than ten thousand times higher than that of the cesium ions. Large particles of nickel ferrocyanide slowly grew at the interface between the two solutions, which reduced the surface energy of the particles and therefore increased the alkali tolerance. The interfacially-synthesized nickel ferrocyanide was possible to prevent the leaching of radioactive cesium from cement-solidified fly ash for a long period. The mechanisms of the formation, selective cesium adsorption, and alkali-induced decomposition of the nickel ferrocyanide were elucidated. Comparison of the cesium adsorption mechanism with that of the other adsorbents revealed that an adsorbent can selectively adsorb cesium ions without much interference from potassium ions, if the following conditions are fulfilled. 1) The adsorption site is small enough for supplying sufficient electrostatic energy for the dehydration of ions adsorbed. 2) Both the cesium and potassium ions are adsorbed as dehydrated ions. 3) The adsorption site is flexible enough for permitting the penetration of dehydrated ions with the size comparable to that of the site. (author)

  13. Quantitative analysis on dose to humans as a result of consuming tuna fish contaminated by cesium radionuclides

    International Nuclear Information System (INIS)

    Khani, J.; Donev, J.M.K.C.

    2014-01-01

    Quantitative empirical data is presented on the dose exposure to North Americans consuming tuna fish that have accumulated concentrations of radioactive isotopes. The two particular radioactive isotopes of interest are cesium-137 and cesium-134. Though biological effects of radiation are a widely debatable topic, the consumption of tuna fish does not support significant increased risk of cancer to humans. An important comparison is made between the elevated levels of radioactive cesium concentrations to naturally occurring radionuclides, namely potassium-40 and polonium-210. It is calculated that naturally occurring radioactive isotopes are in the orders of magnitude greater than the cesium radionuclides in tuna fish. (author)

  14. Comparison of an everolimus-eluting bioresorbable scaffold with an everolimus-eluting metallic stent for the treatment of coronary artery stenosis (ABSORB II)

    DEFF Research Database (Denmark)

    Serruys, Patrick W; Chevalier, Bernard; Sotomi, Yohei

    2016-01-01

    BACKGROUND: No medium-term data are available on the random comparison between everolimus-eluting bioresorbable vascular scaffolds and everolimus-eluting metallic stents. The study aims to demonstrate two mechanistic properties of the bioresorbable scaffold: increase in luminal dimensions...... by intravascular ultrasound assessment of the minimum lumen area (4·32 mm(2) [SD 1·48] vs 5·38 mm(2) [1·51]; p

  15. Are drug-eluting stents the future of SFA treatment?

    Science.gov (United States)

    Bosiers, M; Deloose, K; Keirse, K; Verbist, J; Peeters, P

    2010-02-01

    Drug-eluting stent (DES) technology was developed to prevent early thrombosis and late luminal loss to potentially improve long-term patency rates. Although favorable DES results have recently become available with the Zilver PTX and STRIDES studies, the high price of DES is a major drawback for this technology to become the golden standard for peripheral endovascular therapy in de novo femoro-popliteal (FP) lesions. Nevertheless, DES has the potential to make the difference and to establish itself as an important treatment option in patients presenting with TASC C&D FP lesions who are at high-risk for surgery and for the treatment of in-stent restenosis, where until now, no valuable treatment option has proven to be beneficial.

  16. Alkaline elution of uranium and molybdenum and their recovery

    International Nuclear Information System (INIS)

    Song Wenlan; Wu Peisheng; Zhao Pinzhi; Tao Dening; Xie Chaoyan

    1987-01-01

    The uranium and molybdenum can be simultaneously eluted by using eluant (NH 4 ) 2 CO 3 + (NH 4 ) 2 SO 4 from resin loaded uranium and molybdenum. The ADU is precipitated from eluant by volatilization of ammonia. The molybdenum is extracted by TFA-TBP-kerosene from the filtrate at pH 3.0-3.2 with molybdenum extraction > 98%. Uranium is nearly not extracted. The precipitation of Mo is reached by sulphuric acid after stripping and the ammonium multimolybdate is obtained. This process can give the total recovery more than 99% for U and 90% for Mo. Because of the use of sulphate salt system, the hazard of NO 3 - can be avoided

  17. A prospective, randomized evaluation of a novel everolimus-eluting coronary stent

    DEFF Research Database (Denmark)

    Stone, Gregg W; Teirstein, Paul S; Meredith, Ian T

    2011-01-01

    We sought to evaluate the clinical outcomes with a novel platinum chromium everolimus-eluting stent (PtCr-EES) compared with a predicate cobalt chromium everolimus-eluting stent (CoCr-EES) in patients undergoing percutaneous coronary intervention (PCI)....

  18. 40 CFR 799.6784 - TSCA water solubility: Column elution method; shake flask method.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true TSCA water solubility: Column elution... AND MIXTURE TESTING REQUIREMENTS Product Properties Test Guidelines § 799.6784 TSCA water solubility: Column elution method; shake flask method. (a) Scope—(1) Applicability. This section is intended to meet...

  19. Alternative sample-introduction technique to avoid breakthrough in gradient-elution liquid chromatography of polymers

    NARCIS (Netherlands)

    Reingruber, E.; Bedani, F.; Buchberger, W.; Schoenmakers, P.

    2010-01-01

    Gradient-elution liquid chromatography (GELC) is a powerful tool for the characterization of synthetic polymers. However, gradient-elution chromatograms often suffer from breakthrough phenomena. Breakthrough can be averted by using a sample solvent as weak as the mobile phase. However, this approach

  20. Biolimus-eluting stents with biodegradable polymer versus bare-metal stents in acute myocardial infarction

    DEFF Research Database (Denmark)

    Räber, Lorenz; Kelbæk, Henning; Taniwaki, Masanori

    2014-01-01

    BACKGROUND: This study sought to determine whether the 1-year differences in major adverse cardiac event between a stent eluting biolimus from a biodegradable polymer and bare-metal stents (BMSs) in the COMFORTABLE trial (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Metal...

  1. Cefoperazone and cefoperazone-sulbactam susceptibility tests with anaerobic bacteria by the thioglycolate disk elution method.

    OpenAIRE

    Barry, A L; Packer, R R; Jones, R N

    1985-01-01

    Tests were performed with 104 anaerobic microorganisms to evaluate the thioglycolate disk elution technique for the detection of resistance to cefoperazone and cefoperazone-sulbactam. An unacceptably high false-resistance rate and a poor reproducibility record make the disk elution procedure unsatisfactory for routine testing of this drug or combination of drugs.

  2. A pooled analysis of data comparing sirolimus-eluting stents with bare-metal stents

    NARCIS (Netherlands)

    C.M. Spaulding (Christian); J. Daemen (Joost); H. Boersma (Eric); D.E. Cutlip (Donald); P.W.J.C. Serruys (Patrick)

    2007-01-01

    textabstractBACKGROUND: Although randomized studies have shown a beneficial effect of drug-eluting stents in reducing the risk of repeated revascularization, these trials were underpowered to compare rates of death and myocardial infarction. The long-term safety of drug-eluting stents has been

  3. Drug-eluting stents studies in mice: do we need atherosclerosis to study restenosis?

    NARCIS (Netherlands)

    Pires, Nuno M. M.; Jukema, J. Wouter; Daemen, Mat J. A. P.; Quax, Paul H. A.

    2006-01-01

    In 2001, the first human study with drug-eluting stents (DES) was published showing a nearly complete abolition of restenosis by using a sirolimus-eluting stent. This success was very encouraging to test new compounds in combination with the DES platform. Nevertheless, several other anti-restenotic

  4. Elution of labile fluorescent dye from nanoparticles during biological use.

    Directory of Open Access Journals (Sweden)

    Tiziana Tenuta

    Full Text Available Cells act as extremely efficient filters for elution of unbound fluorescent tags or impurities associated with nanoparticles, including those that cannot be removed by extensive cleaning. This has consequences for quantification of nanoparticle uptake and sub-cellular localization in vitro and in vivo as a result of the presence of significant amount of labile dye even following extensive cleaning by dialysis. Polyacrylamide gel electrophoresis (PAGE can be used to monitor the elution of unbound fluorescent probes from nanoparticles, either commercially available or synthesized in-house, and to ensure their complete purification for biological studies, including cellular uptake and sub-cellular localisation. Very different fluorescence distribution within cells is observed after short dialysis times versus following extensive dialysis against a solvent in which the free dye is more soluble, due to the contribution from free dye. In the absence of an understanding of the presence of residual free dye in (most labeled nanoparticle solutions, the total fluorescence intensity in cells following exposure to nanoparticle solutions could be mis-ascribed to the presence of nanoparticles through the cell, rather than correctly assigned to either a combination of free-dye and nanoparticle-bound dye, or even entirely to free dye depending on the exposure conditions (i.e. aggregation of the particles etc. Where all of the dye is nanoparticle-bound, the particles are highly localized in sub-cellular organelles, likely lysosomes, whereas in a system containing significant amounts of free dye, the fluorescence is distributed through the cell due to the free diffusion of the molecule dye across all cellular barriers and into the cytoplasm.

  5. Elution Profiles of Two Methods of Antibiotic Tibial Nail Preparations.

    Science.gov (United States)

    Karek, Matthew R; Jackson, Nancy M; Flynn, Jeffrey C; Vaidya, Rahul; Markel, David C

    2017-05-01

    Interlocking nails coated with antibiotic-supplemented cement provide effective treatment of infected long bone nonunion, but the thicker coating on guidewires may provide greater antibacterial activity. This study compared the properties of cement cured on each construct by evaluating 2-cm segments of 8-mm interlocking nails and 3.5-mm guidewires coated with antibiotic-supplemented cement. Each construct (n=7 for each group) was coated with polymethylmethacrylate cement (Simplex; Stryker Orthopaedics, Mahwah, New Jersey) containing either 1 g tobramycin or 1 g vancomycin powder plus 2.2 g tobramycin powder. A No. 40 French polyvinyl chloride chest tube was used as a mold for all constructs. Segments were soaked in sterile phosphate-buffered saline, and entire aliquots were exchanged at various intervals over a 6-week period. Antibiotic concentration, antibacterial activity, cement curing temperature, and porosity were measured. At least half of the total elution of antibiotics occurred within the first 24 hours for all constructs. For the tobramycin-only cement, no differences between constructs were observed. For constructs containing both antibiotics, interlocking nails showed more antibiotic release than guidewires at most time points (PAntibiotics were released for 6 weeks and continued to inhibit Staphylococcus aureus growth. Cement curing temperatures for interlocking nails were lower than those for guidewires (Pantibiotic released did not directly relate to porosity for any construct type. Interlocking nails coated with antibiotic-supplemented cement may provide greater antibiotic delivery to infected long bone nonunion compared with guidewires. A thin mantle of cement may allow greater elution, possibly as a result of cooler exothermic reactions. [Orthopedics. 2017; 40(3):e436-e442.]. Copyright 2017, SLACK Incorporated.

  6. Co-precipitation and solubility studies of cesium, potassium and sodium tetraphenylborate

    International Nuclear Information System (INIS)

    Peterson, R.A.

    2000-01-01

    This report contains the results from a study requested by High Level Waste on the co-precipitation and solubility of cesium, potassium, and sodium tetraphenylborate. Co-precipitation of cesium (Cs), potassium (K), and sodium (Na) tetraphenylborate (TPB) helps determine the efficiency of reagent usage in the Small Tank Precipitation Process. This process uses NaTPB to remove cesium from waste by means of precipitation. Previous studies by McCabe suggested that if the sodium ion concentration [Na + ] increased the rate at which cesium tetraphenylborate (CsTPB) precipitates also increases. Serkiz also demonstrated that the precipitation of potassium tetraphenylborate (KTPB) in the presence of high [Na + ] (∼5M) appears to produce a mixed solid phase composed of NaTPB and KTPB together in the crystal lattice. In the crystallographic structure of these three tetraphenylborate salts (Cs,K,NaTPB), the tetraphenylborate ion dominates the size of the crystals. Also, note that the three crystals have nearly identical structures with the exception of two additional peaks in the cesium pattern. Given these similarities, TPB precipitation in the presence of Na + , Cs + and K + likely produces an impure isomorphic crystalline mixture of CsTPB, KTPB and NaTPB. The authors speculate that the primary crystalline structure resembles that of KTPB with NaTPB and CsTPB mixed throughout the crystal structure. The precipitation of NaTPB makes some of the anticipated excess tetraphenylborate relatively unavailable for precipitation of cesium. Thus, the amount of excess tetraphenylborate required to completely precipitate all of the potassium and cesium may increase significantly

  7. Preparation and characterization of cesium-137 aluminosilicate pellets for radioactive source applications

    International Nuclear Information System (INIS)

    Schultz, F.J.; Tompkins, J.A.; Haff, K.W.; Case, F.N.

    1981-07-01

    Twenty-seven fully loaded 137 Cs aluminosilicate pellets were fabricated in a hot cell by the vacuum hot pressing of a cesium carbonate/montmorillonite clay mixture at 1500 0 C and 570 psig. Four pellets were selected for characterization studies which included calorimetric measurements, metallography, scanning electron microscope and electron backscattering (SEM-BSE), electron microprobe, x-ray diffraction, and cesium ion leachability measurements. Each test pellet contained 437 to 450 curies of 137 Cs as determined by calorimetric measurements. Metallographic examinations revealed a two-phase system: a primary, granular, gray matrix phase containing large and small pores and small pore agglomerations, and a secondary fused phase interspersed throughout the gray matrix. SEM-BSE analyses showed that cesium and silicon were uniformly distributed throughout both phases of the pellet. This indicated that the cesium-silicon-clay reaction went to completion. Aluminum homogeneity was unconfirmed due to the high background noise associated with the inherent radioactivity of the test specimens. X-ray diffraction analyses of both radioactive and non-radioactive aluminosilicate pellets confirmed the crystal lattice structure to be pollucite. Cesium ion quasistatic leachability measurements determined the leach rates of fully loaded 137 Cs sectioned pollucite pellets to date to be 4.61 to 34.4 x 10 -10 kg m -2 s -1 , while static leach tests performed on unsectioned fully loaded pellets showed the leach rates of the cesium ion to date to be 2.25 to 3.41 x 10 -12 kg m -2 s -1 . The cesium ion diffusion coefficients through the pollucite pellet were calculated using Fick's first and second laws of diffusion. The diffusion coefficients calculated for three tracer level 137 Cs aluminosilicate pellets were 1.29 x 10 -16 m 2 s -1 , 6.88 x 10 -17 m 2 s -1 , and 1.35 x 10 -17 m 2 s -1 , respectively

  8. Modeling and analysis of the affinity filtration process, including broth feeding, washing, and elution steps.

    Science.gov (United States)

    He, L Z; Dong, X Y; Sun, Y

    1998-01-01

    Affinity filtration is a developing protein purification technique that combines the high selectivity of affinity chromatography and the high processing speed of membrane filtration. In this work a lumped kinetic model was developed to describe the whole affinity filtration process, including broth feeding, contaminant washing, and elution steps. Affinity filtration experiments were conducted to evaluate the model using bovine serum albumin as a model protein and a highly substituted Blue Sepharose as an affinity adsorbent. The model with nonadjustable parameters agreed fairly to the experimental results. Thus, the performance of the affinity filtration in processing a crude broth containing contaminant proteins was analyzed by computer simulations using the lumped model. The simulation results show that there is an optimal protein loading for obtaining the maximum recovery yield of the desired protein with a constant purity at each operating condition. The concentration of a crude broth is beneficial in increasing the recovery yield of the desired protein. Using a constant amount of the affinity adsorbent, the recovery yield can be enhanced by decreasing the solution volume in the stirred tank due to the increase of the adsorbent weight fraction. It was found that the lumped kinetic model was simple and useful in analyzing the whole affinity filtration process.

  9. Primary standardization of cesium-137 for international intercomparison

    International Nuclear Information System (INIS)

    Srivastava, P.K.

    1977-01-01

    Primary standards of cesium-137 are of great importance for precise radiation measurements because, due to its simple decay-scheme and long half-life, it is widely used for the calibration of radiation detectors. Also 137 Cs is used for the measurement of fission-yield and uranium burn-up in reactor engineering studies. In view of these, an international intercomparison was organised on a limited scale to correlate the standards established at the Bhabha Atomic Research Centre (BARC), Bombay(India) and Physikalisch-Technische Bundesanstalt (PTB), West Germany. The ''efficiency tracing technique'' was developed at BARC for the primary standardization of 137 Cs for this intercomparison. Two tracers, namely 82 Br and 60 Co, were employed to trace the beta efficiency of the 4 πβ-γ coincidence counting system. It is shown that this technique offers high accuracy and inherent reliability. The ''tracing-technique'' for 137 Cs standardization is briefly described. The gravimetric method of dilution and preparation of mixed sources of 137 Cs - 82 Br and 137 Cs - 60 Co are given. The various counting parameters and settings are included. Data reduction and the estimation of systematic and statistical errors are discussed. The results of the intercomparison, which are also included, show that the agreement between the measurments of BARC and PTB is within 0.5%. (author)

  10. Desorption of cesium from granite under various aqueous conditions

    International Nuclear Information System (INIS)

    Wang, T.-H.; Li, M.-H.; Wei, Y.-Y.; Teng, S.-P.

    2010-01-01

    In this work the desorption of cesium ions from crushed granite in synthetic groundwater (GW) and seawater (SW) was investigated. Results were compared with those obtained in deionized water (DW) and in two kinds of extraction solutions, namely: MgCl 2 and NaOAc (sodium acetate). In general, the desorption rate of Cs from crushed granite increased proportionally with initial Cs loadings. Also, amounts of desorbed Cs ions followed the tendency in the order SW>GW>NaOAc∼MgCl 2 >DW solutions. This indicated that the utilization of extraction reagents for ion exchange will underestimate the Cs desorption behavior. Fitting these experimental data by Langmuir model showed that these extraction reagents have reduced Cs uptake by more than 90%, while only less than 1% of adsorbed Cs ions are still observed in GW and SW solutions in comparison to those in DW. Further SEM/EDS mapping studies clearly demonstrate that these remaining adsorbed Cs ions are at the fracture areas of biotite.

  11. Cesium immobilization in (Ba,Cr)-hollandites: Effects on structure

    Science.gov (United States)

    Tumurugoti, Priyatham; Sundaram, S. K.; Misture, Scott T.

    2018-02-01

    Hollandites with compositions Ba1.15-xCs2xCr2.3Ti5.7O16 (0 ≤ x ≤ 1.15) intended for the immobilization of cesium (Cs) from nuclear waste have been prepared, characterized, and analyzed for Cs retention properties. Sol-gel synthesized powders were used for structural characterization using a combination of X-ray, neutron, and electron diffraction techniques. Phase-pure hollandites adopting tetragonal (I4/m) or monoclinic symmetry (I2/m) were observed to form in the compositional range 0 ≤ x ≤ 0.4. Structural models for the compositions, x = 0, 0.15, and 0.25 were developed from Rietveld analysis of powder diffraction data. Refined anisotropic displacement parameters (βij) for the Ba and Cs ions in the hollandite tunnels indicate local disorder of Ba/Cs along the tunnel direction. In addition, weak superlattice reflections were observed in X-ray and electron diffraction patterns that were due to the compositional modulation i.e., ordering of ions and vacancies along tunnel direction. Our overall observations suggest the phase-pure hollandites studied assumed supercell structures with ordered tunnel cations, which in turn have positional disorder in individual supercells.

  12. Hanford Isotope Project strategic business analysis Cesium-137 (Cs-137)

    International Nuclear Information System (INIS)

    1995-10-01

    The purpose of this business analysis is to address the beneficial reuse of Cesium 137 (Cs-137) in order to utilize a valuable national asset and possibly save millions of tax dollars. Food irradiation is the front runner application along with other uses. This business analysis supports the objectives of the Department of Energy National Isotope Strategy distributed in August 1994 which describes the DOE plans for the production and distribution of isotope products and services. As part of the Department's mission as stated in that document. ''The Department of Energy will also continue to produce and distribute other radioisotopes and enriched stable isotopes for medical diagnostics and therapeutics, industrial, agricultural, and other useful applications on a businesslike basis. This is consistent with the goals and objectives of the National Performance Review. The Department will endeavor to look at opportunities for private sector to co-fund or invest in new ventures. Also, the Department will seek to divest from ventures that can more profitably or reliably be operated by the private sector.''

  13. Sorption Coefficients for Iodine, Silver, and Cesium on Dust Particles

    International Nuclear Information System (INIS)

    Stempniewicz, M.M.; Goede, P.

    2014-01-01

    This paper describes the work performed to find relevant experimental data and find the sorption coefficients that represent well the available data for cesium, iodine, and silver on dust particles. The purpose of this work is to generate a set of coefficients that may be recommended for the computer code users. The work was performed using the computer code SPECTRA. Calculations were performed for the following data: • I-131 on AVR dust; • Ag-110m on AVR dust; • Cs-13 and Cs-137 on AVR dust. Available data was matched using the SPECTRA Sorption Model. S = A(T) · C V -B(T) · C d . The results are summarized as follows: • The available data can be correlated. The data scatter is about 4 orders of magnitude. Therefore the coefficients of the Langmuir isotherms vary by 4 orders of magnitude. • Sorption rates are higher at low temperatures and lower at high temperatures. This tendency has been observed in the data compiled at Oak Ridge. It is therefore surmised that the highest value of the sorption coefficients are appropriate for the low temperatures and the lowest value of the sorption coefficients are appropriate for the high temperatures. The recommended sorption coefficients are presented in this paper. • The present set of coefficients is very rough and should be a subject for future verification against experimental data. (author)

  14. Hanford Isotope Project strategic business analysis Cesium-137 (Cs-137)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    The purpose of this business analysis is to address the beneficial reuse of Cesium 137 (Cs-137) in order to utilize a valuable national asset and possibly save millions of tax dollars. Food irradiation is the front runner application along with other uses. This business analysis supports the objectives of the Department of Energy National Isotope Strategy distributed in August 1994 which describes the DOE plans for the production and distribution of isotope products and services. As part of the Department`s mission as stated in that document. ``The Department of Energy will also continue to produce and distribute other radioisotopes and enriched stable isotopes for medical diagnostics and therapeutics, industrial, agricultural, and other useful applications on a businesslike basis. This is consistent with the goals and objectives of the National Performance Review. The Department will endeavor to look at opportunities for private sector to co-fund or invest in new ventures. Also, the Department will seek to divest from ventures that can more profitably or reliably be operated by the private sector.``

  15. Drug eluting balloon versus drug eluting stent in percutaneous coronary interventions: insights from a meta-analysis of 1462 patients.

    Science.gov (United States)

    Lupi, Alessandro; Rognoni, Andrea; Secco, Gioel Gabrio; Porto, Italo; Nardi, Federico; Lazzero, Maurizio; Rossi, Lidia; Parisi, Rosario; Fattori, Rossella; Genoni, Giulia; Rosso, Roberta; Stella, Pieter R; Sheiban, Imad; Bolognese, Leonardo; Liistro, Francesco; Bongo, Angelo Sante; Agostoni, Pierfrancesco

    2013-10-12

    Drug eluting balloons (DEB) have been developed to overcome the limitations of drug eluting stents (DES), but clinic results of various DEB studies are still not consistent. Thus, we performed a meta-analysis to compare outcomes of DEB and DES for the treatment of coronary artery disease (CAD). Medline/Web databases were searched for studies comparing DEB and DES for obstructive CAD, reporting late lumen loss (LLL) and rates for overall mortality, myocardial infarction (MI), stent thrombosis (ST) and target lesion revascularization (TLR). 8 studies (1462 patients) were included in the meta-analysis. Compared with DES, DEB treated patients showed non-significantly higher LLL (weighted mean difference [WMD] 0.32, 95% confidence interval [CI] -0.15 to 0.78, P=0.18) and non-significantly higher rate of binary restenosis (odds ratio [OR] 1.40 [0.68-2.48], P=0.36). Mortality (OR 1.13[0.54-2.37], P=0.74), MI (OR 0.95, [0.50-1.80], P=0.87), ST (OR 1.12, [0.34-4.19], P=0.77) and TLR rates (OR 1.19[0.60-2.38], P=0.61) were similar between the 2 treatments. A pre-specified meta-regression analysis showed that LLL WMD and TLR OR were inversely correlated to the prevalence of diabetes (Pmeta-analysis showed that compared to DES, DEB use resulted in similar clinical efficacy and safety. Thus DEB could be considered a reasonable alternative to DES for the treatment of CAD in selected clinical settings (Clinicaltrials.gov identifier: NCT01760200). © 2013.

  16. Tribological properties of pulsed laser deposited thin films of cesium oxythiomolybdate

    Science.gov (United States)

    Strong, Karla Lynne

    Cesium oxythiomolybdate, Cs2MoOS3, has been investigated as a pulsed laser deposited solid lubricant for Si3N4 bearings. First, the dynamics of pulsed laser ablation of Cs2MoOS 3 were studied. Based on film thicknesses grown at angles to the target normal, the ejected species were not markedly forward peaked (thickness = cos2.3theta). In addition, there was no discernible variation in film stoichiometry with angle. The primary positive ions detected by time of flight mass spectrometry were OS+, S2 +, Mo+, Cs+, and Mo2 +. The drifted Maxwell-Boltzmann velocity distribution applied. The positive ions had energies between 120--820 eV, and likely contributed the excellent adhesion of the film to substrate surfaces. Cesium oxythiomolybdate powders and a Cs2MoOS3/Si 3N4, mixture were heated in air and analyzed to study the compound's oxidative stability. Oxidation of Cs2MoOS3 was complex, producing cesium oxides, Cs2, MoO4, Cs 2So4, and molybdenum oxides at 600°C. Oxidation of the mixture produced cesium silicate glass in addition to the other compounds. Cesium oxides were not detected in the mixture at higher temperatures. Cesium oxythiomolybdate coatings were produced by pulsed laser deposition and tested in sliding friction between 25 - 800°C. Several substrates were chosen to study lubricant/substrate interaction, including Si3N 4, SiC, Al2O3, ZrO2, and Inconel. Cs 2MoOS3 was a superb lubricant on Si3N4 from 600--750°C, and on SiC between 500--600°C, with coefficients of friction below 0.1. Wear protection was also excellent under these conditions. The formation of a silica scale on the substrate surface, followed by diffusion of melted cesium oxides, created a low shear strength cesium silicate glass with an optimum viscosity for lubrication. Cesium molybdate and MoO3 provided lubrication between 400--700°C, regardless of the presence of a silica scale. Coefficients of friction on non Si-containing substrates were below 0.2 at 600°C, and good wear protection

  17. Strontium-90 and cesium-137 in sea water (from Jul 1984 to Sep 1984)

    International Nuclear Information System (INIS)

    1984-01-01

    Monitoring results are presented on strontium-90 and cesium-137 contents in sea water of 11 sampling points all over Japan from Hokkaido to Okinawa coast. Sampling points were selected by the criterion that the effect of terrestrial fresh water and atmospheric precipitation was expected to be ignorable. Sample collection was carried out in the Period from July to September, 1984. With a special care for prevention of any contamination. The collected sea water samples were acidified immediately and they were served for radiochemical separation and purification of strontium-90 and cesium-137. Radiation counting was made for yttrium-90 hydroxide sample and cesium chloroplatinate sample with a low background beta counter normally for 60 minutes. As for strontium-90 contents in sea water, they were ranged from 0.07 +- 0.010 pCi/l (Mutsu Bay, Aomori) to 0.11 +- 0.012 pCi/l (Off Niigata Port, Niigata) and the average value was 0.09 pCi/l. As for cesium-137 contents, they were ranged from 0.08 +- 0.011 pCi/l (Ise Bay, Aichi) to 0.14 +- 0.012 pCi/l (Yamaguchi Bay, Yamaguchi) and the average value was 0.106 pCi/l. It is clarified that no abnormal values were determined for strontium-90 or cesium-137 contents in coastal sea water around Japan from a fallout origin. (Takagi, S.)

  18. Preparation of Modified Kaolin Filler with Cesium and Its Application in Security Paper

    Directory of Open Access Journals (Sweden)

    Houssni El-Saied

    2013-01-01

    Full Text Available In this study, cesium was added intentionally during paper manufacture for protecting the papers against forgery and counterfeiting by sorbing cesium ions (Cs+ on kaolin, used as special filler in papermaking. The sorption of cesium from aqueous solution by kaolin was studied as a function of pH, shaking time, cesium initial concentration, and mass of kaolin using batch technique. The results showed that a solution containing 10 mg/L Cs+ and 250 mg of kaolin at pH 6 can be used to modify the kaolin. Paper handsheets were prepared containing various percentages of the modified kaolin. The mechanical and optical properties of paper handsheets were studied. The prepared paper handsheets were irradiated by gamma irradiation using different doses. Fourier transform infrared (FTIR spectroscopy was used to study the effect of kaolin modification by cesium and gamma irradiation on paper handsheets properties. The results indicated that modified kaolin enhanced the mechanical and optical properties of paper handsheets. Electron spin resonance (ESR spectroscopy and laser-induced breakdown spectroscopy (LIBS were also used. They provided rapid, sensitive and nondestructive techniques in differentiating between different questioned documents. This study presents a new concept in manufacturing security papers and anticounterfeiting applications.

  19. Efficiency of fly ash belite cement and zeolite matrices for immobilizing cesium

    International Nuclear Information System (INIS)

    Goni, S.; Guerrero, A.; Lorenzo, M.P.

    2006-01-01

    The efficiency of innovative matrices for immobilizing cesium is presented in this work. The matrix formulation included the use of fly ash belite cement (FABC-2-W) and gismondine-type Na-P1 zeolite, both of which are synthesized from fly ash of coal combustion. The efficiency for immobilizing cesium is evaluated from the leaching test ANSI/ANS 16.1-1986 at the temperature of 40 deg. C, from which the apparent diffusion coefficient of cesium is obtained. Matrices with 100% of FABC-2-W are used as a reference. The integrity of matrices is evaluated by porosity and pore-size distribution from mercury intrusion porosimetry, X-ray diffraction and nitrogen adsorption analyses. Both matrices can be classified as good solidify systems for cesium, specially the FABC-2-W/zeolite matrix in which the replacement of 50% of belite cement by the gismondine-type Na-P1 zeolite caused a decrease of two orders of magnitude of cesium mean Effective Diffusion Coefficient (D e ) (2.8e-09 cm 2 /s versus 2.2e-07 cm 2 /s, for FABC-2-W/zeolite and FABC-2-W matrices, respectively)

  20. Cesium-137 in soil texture fractions and its impact on Cesium-137 soil-to-plant transfer

    International Nuclear Information System (INIS)

    Gerzabek, M.H.; Mohamad, S.A.; Mueck, K.

    1992-06-01

    Field studies at two sites contaminated by the Chernobyl fallout showed 137 Cesium (Cs) soil-to-plant transfer factors in wheat, rye and potato. Transfer values ranged from 0.0017 (potato tuber) to 0.07 (wheat straw). Generally transfer coefficients in cereal grains and potato tubers were significantly below the values of the shoots. A comparison of the two sites led to the conclusion that for all plants investigated 137 Cs transfer factors were higher in Lower Austria (Calcic Chernozem) than in Upper Austria (Eutric Cambisol). The specific activities of the texture fractions of the two soil types increased from sand to silt and clay. In the Calcic Chernozem the ratio of the 137 Cs activity in the silt fraction to the total activity in the soil was considerably higher than in the Eutric Cambisol. At the same time extractability of 137 Cs from the silt fraction of the latter soil was clearly lower. Both results mainly were attributed to the differences between the soils according to the organic matter content of the silt fractions, the Calcic Chernozem being seven times higher. Therefore, the differences in the 137 Cs-soil-to-plant transfer can be attributed partly to these soil characteristics. (authors)

  1. Sympathetic cooling in a rubidium cesium mixture: Production of ultracold cesium atoms; Sympathetisches Kuehlen in einer Rubidium-Caesium-Mischung: Erzeugung ultrakalter Caesiumatome

    Energy Technology Data Exchange (ETDEWEB)

    Haas, M.

    2007-07-01

    This thesis presents experiments for the production of ultracold rubidium cesium mixture in a magnetic trap. The long-termed aim of the experiment is the study of the interaction of few cesium atoms with a Bose-Einstein condensate of rubidium atoms. Especially by controlled variation of the cesium atom number the transition in the description of the interaction by concepts of the one-particle physics to the description by concepts of the many-particle physics shall be studied. The rubidium atoms are trapped in a magneto-optical trap (MOT) and from there reloaded into a magnetic trap. In this the rubidium atoms are stored in the state vertical stroke f=2,m{sub f}=2 right angle of the electronic ground state and evaporatively cooled by means of microwave-induced transitions into the state vertical stroke f=1,m{sub f}=1] (microwave cooling). The cesium atoms are also trppaed in a MOT and into the same magnetic trap reloaded, in which they are stored in the state vertical stroke f=4,m{sub f}=4 right angle of the electronic ground state together with rubidium. Because of the different hyperfine splitting only rubidium is evaporatively cooled, while cesium is cooled jointly sympathetically - i.e. by theramal contact via elastic collisions with rubidium atoms. The first two chapters contain a description of interatomic interactions in ultracold gases as well as a short summary of theoretical concepts in the description of Bose-Einstein condensates. The chapters 3 and 4 contain a short presentation of the methods applied in the experiment for the production of ultracold gases as well as the experimental arrangement; especially in the framework of this thesis a new coil system has been designed, which offers in view of future experiments additionally optical access for an optical trap. Additionally the fourth chapter contains an extensive description of the experimental cycle, which is applied in order to store rubidium and cesium atoms together into the magnetic trap. The

  2. Effect of doping on the electronic structures and optical properties of Cesium Iodide

    Science.gov (United States)

    Weir, Victor Julian

    Cesium Iodide (CsI) is an important phosphor in medical imaging. It converts x-rays into visible light. The effects of dopants on the electronic band structure and optical properties were studied theoretically using density functional theory with a local density approximation. The studies were done using Dmol 3 and visualized with Material Studio. The effect of Thallium (Tl) doping on the surfaces was simulated by introducing Thallium as a substitutional impurity. The effect of the dopant on the surfaces was investigated by calculating the plasma frequency edge and radiant quantum efficiencies (RQE) from the analysis of the band structure. The results for the plasma frequency edge are in agreement with the known experimental data on the transmission and reflectivity of thin CsI films as well as bulk CsI crystals. The radiant quantum efficiencies and relative light output increase for increasing doping concentrations and then level off probably due to saturation. The effect of oxygen poisoning was simulated by substituting oxygen as an impurity on the CsI 110 surface. Water adsorption was simulated by docking a water molecule onto the CsI 110 surface. There was no significant change in the radiant quantum efficiency for different doping concentrations of oxygen on the surface. The effect of water adsorption on the surface, likewise, showed no effect on the radiant QE. The effect of Europium (Eu) co-dopant was simulated by co-doping CsI:Tl with Europium as a substitutional impurity. The reduction in the afterglow of CsI:Tl,Eu is explained by the reduction in the contribution of Tl 0, and Tl2+ centers. The red-shift of luminescence is explained by the dominance of the Eu2+ ion that has a transition state emitting in the yellow part of the spectrum compared with the Tl transition that emits in the green range. Furthermore, the narrowing of the band gap with increasing Eu doping concentration contributes to reducing the emission from Tl. There were no significant

  3. The effectiveness of radioactive cesium removal countermeasure due to the Prussian blue nonwoven-textile fabrics proposed by International Research Institute for Nuclear Decommissioning

    International Nuclear Information System (INIS)

    Inamori, Yuhei; Inamori, Ryuhei; Kakazu, Kunihiko; Miura, Nozomu

    2014-01-01

    The effectiveness of radioactive-cesium removal countermeasure by using Prussian blue is described: The verified technique for practical use to countermeasure of cesium-contaminated water by using nonwoven textile fabrics; the evaluation of effectiveness of cesium adsorbent, Prussian blue, by using model ecosystem of aquatic animals and plants. (M.H.)

  4. Exploring doxorubicin localization in eluting TiO2 nanotube arrays through fluorescence correlation spectroscopy analysis.

    Science.gov (United States)

    De Santo, Ilaria; Sanguigno, Luigi; Causa, Filippo; Monetta, Tullio; Netti, Paolo A

    2012-11-07

    Drug elution properties of TiO(2) nanotube arrays have been largely investigated by means of solely macroscopic observations. Controversial elution performances have been reported so far and a clear comprehension of these phenomena is still missing as a consequence of a lack of molecular investigation methods. Here we propose a way to discern drug elution properties of nanotubes through the evaluation of drug localization by Fluorescence Correlation Spectroscopy (FCS) analysis. We verified this method upon doxorubicin elution from differently loaded TiO(2) nanotubes. Diverse elution profiles were obtained from nanotubes filled by soaking and wet vacuum impregnation methods. Impregnated nanotubes controlled drug diffusion up to thirty days, while soaked samples completed elution in seven days. FCS analysis of doxorubicin motion in loaded nanotubes clarified that more than 90% of drugs dwell preferentially in inter-nanotube spaces in soaked samples due to decorrelation in a 2D fashion, while a 97% fraction of molecules showed 1D mobility ascribable to displacements along the nanotube vertical axis of wet vacuum impregnated nanotubes. The diverse drug localizations inferred from FCS measurements, together with distinct drug-surface interaction strengths resulting from diverse drug filling techniques, could explain the variability in elution kinetics.

  5. Towards enhanced automated elution systems for waterborne protozoa using megasonic energy.

    Science.gov (United States)

    Horton, B; Katzer, F; Desmulliez, M P Y; Bridle, H L

    2018-02-01

    Continuous and reliable monitoring of water sources for human consumption is imperative for public health. For protozoa, which cannot be multiplied efficiently in laboratory settings, concentration and recovery steps are key to a successful detection procedure. Recently, the use of megasonic energy was demonstrated to recover Cryptosporidium from commonly used water industry filtration procedures, forming thereby a basis for a simplified and cost effective method of elution of pathogens. In this article, we report the benefits of incorporating megasonic sonication into the current methodologies of Giardia duodenalis elution from an internationally approved filtration and elution system used within the water industry, the Filta-Max®. Megasonic energy assisted elution has many benefits over current methods since a smaller final volume of eluent allows removal of time-consuming centrifugation steps and reduces manual involvement resulting in a potentially more consistent and more cost-effective method. We also show that megasonic sonication of G. duodenalis cysts provides the option of a less damaging elution method compared to the standard Filta-Max® operation, although the elution from filter matrices is not currently fully optimised. A notable decrease in recovery of damaged cysts was observed in megasonic processed samples, potentially increasing the abilities of further genetic identification options upon isolation of the parasite from a filter sample. This work paves the way for the development of a fully automated and more cost-effective elution method of Giardia from water samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Neointimal hyperplasia after sirolimus-eluting and paclitaxel-eluting stent implantation in diabetic patients: the Randomized Diabetes and Drug-Eluting Stent (DiabeDES) Intravascular Ultrasound Trial

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Maeng, Michael; Thayssen, Per

    2008-01-01

    AIMS: Patients with diabetes have increased risk of in-stent restenosis after coronary stent implantation owing to neointimal hyperplasia (NIH). The aim of the study was to evaluate the extent and distribution of NIH with intravascular ultrasound (IVUS) after coronary artery stenting with sirolimus......-eluting (Cypher) or paclitaxel-eluting (Taxus) stents in diabetic patients. METHODS AND RESULTS: One hundred and thirty diabetic patients were randomized to Cypher or Taxus stent implantation. IVUS was performed at 8 month follow-up. NIH volume was significantly reduced in the Cypher group when compared...

  7. Use of cesium-137 methodology in the evaluation of superficial erosive processes

    International Nuclear Information System (INIS)

    Andrello, Avacir Casanova; Appoloni, Carlos Roberto; Guimaraes, Maria de Fatima; Nascimento Filho, Virgilio Franco do

    2003-01-01

    Superficial erosion is one of the main soil degradation agents and erosion rates estimations for different edaphic climate conditions for the conventional models, as USLE and RUSLE, are expensive and time-consuming. The use of cesium- 137 anthropogenic radionuclide is a new methodology that has been much studied and its application in the erosion soil evaluation has grown in countries as USA, UK, Australia and others. A brief narration of this methodology is being presented, as the development of the equations utilized for the erosion rates quantification through the cesium- 137 measurements. Two watersheds studied in Brazil have shown that the cesium- 137 methodology was practicable and coherent with the survey in field for applications in erosion studies. (author)

  8. Fluoro-alcohol phase modifiers and process for cesium solvent extraction

    Science.gov (United States)

    Bonnesen, Peter V.; Moyer, Bruce A.; Sachleben, Richard A.

    2003-05-20

    The invention relates to a class of phenoxy fluoro-alcohols, their preparation, and their use as phase modifiers and solvating agents in a solvent composition for the extraction of cesium from alkaline solutions. These phenoxy fluoro-alcohols comply with the formula: ##STR1## in which n=2 to 4; X represents a hydrogen or a fluorine atom, and R.sup.2 -R.sup.6 are hydrogen or alkyl substituents. These phenoxy fluoro-alcohol phase modifiers are a necessary component to a robust solvent composition and process useful for the removal of radioactive cesium from alkaline nuclear waste streams. The fluoro-alcohols can also be used in solvents designed to extract other cesium from acidic or neutral solutions.

  9. Effects of mineralogy on the sorption of strontium and cesium onto Calico Hills tuff

    International Nuclear Information System (INIS)

    Meyer, R.E.; Arnold, W.D.; Case, F.I.; O'Kelley, G.D.; Land, J.F.

    1990-01-01

    Sorption and desorption measurements were made of strontium and cesium onto clinoptilolite and Calico Hills Tuff. The object was to see whether there was a correlation between sorption of strontium and cesium onto Calico Hills Tuff and the clinoptilolite based on the content of clinoptilolite in the Calico Hills Tuff. If sorption onto Calico Hills Tuff is solely due to the presence of clinoptilolite, then the ratios of the sorption ratios on tuff to those on clinoptilolite at similar conditions should be the weight fraction of the clinoptilolite in the tuff. The experimental evidence showed that the ratios were generally near 0.5 for both cesium and strontium sorption and that ion-exchange processes were operative for the clinoptilolite and the tuff. However, the ratios differed to a small extent for different conditions, and there were indications that other sorption processes were also involved. 7 refs., 7 figs., 2 tabs

  10. Use of cesium-137 to assess soil erosion rates under soybean, coffee and pasture

    International Nuclear Information System (INIS)

    Andrello, A.C.; Appoloni, C.R.; Guimaraes, M.F.

    2003-01-01

    The methodology cesium-137 was used to assess soil erosion and deposition rates in a small watershed with varied crops, at 23 deg 16' S and 51 deg 17' W, in a district of Cambe, Parana State, Brazil. A theoretical equation which considers soil loss or gain directly proportional to the cesium-137 redistribution was utilized in this study. In the watershed, soil redistribution was assessed by transect sampling, and the regional input of cesium-137 by radioactive rainfall determined based on samples from a point in the native forest. Most sampled pasture points presented soil loss, as well as the points in the soybean area under conventional tillage, while in the coffee crop there was neither soil loss nor gain. (author)

  11. Studies of cesium and strontium migration in unconsolidated Canadian geological materials

    International Nuclear Information System (INIS)

    Gillham, R.W.; Lindsay, L.E.; Reynolds, W.D.; Kewen, T.J.; Cherry, J.A.; Reddy, M.R.

    1981-06-01

    Distribution coefficients (Ksub(d)) were measured for cesium and strontium in 16 samples of Canadian unconsolidated geological materials. The samples were collected to cover a wide range of grain size, clay-mineral composition, cation exchange capacity and carbonate mineral content. Distribution coefficients ranged between 10 2 and 2.0 x 10 4 ml/g for cesium and between 2.5 and 10 2 ml/g for strontium, indicating that most unconsolidated geological materials have a substantial ability to retard the migration of cesium, while strontium could generally be expected to be somewhat more mobile. The measured K values were not significantly correlated with the measured soil properties, but appeared to be significantly affected by the background concentration of stable isotopes of the respective radionuclides

  12. Determination of the cesium distribution coeficient in Goiania and Abadia de Goias cities soils

    International Nuclear Information System (INIS)

    Marumo, J.T.; Suarez, A.A.

    1989-01-01

    In September, 1987, an unauthorized removal of a cesium-therapy unit and its violation caused an accident, where several places of Goiania's city, capital of Goias, Brazil, were contaminated. The removal of the radioactive wastes generated from decontamination process, was made to Abadia de Goias's city (near Goiania), where an interim storage was constructed. Soil samples collected from the 57 th Street (Goiania) and from the interim storage permitted to determine, through static method, the cesium distribution coefficient for different cesium solution concentrations. Those results allows for some migration/retention evaluations in disposal site selection. Some soils parameters (water content, density, granulometric analysis etc) as well as clay minerals constituents were also determined. (author) [pt

  13. Determination of the cesium distribution coefficient in Goiania and Abadia de Goias cities soils

    International Nuclear Information System (INIS)

    Marumo, J.T.; Suarez, A.A.

    1989-10-01

    In September, 1987, an unauthorized removal of a cesium-therapy unit and its violation caused an accident, where several places of Goiania's city, capital of Goias, Brazil, were contaminated. The removal of the radioactive wastes generated from decontamination process, was made to Abadia de Goias city (near Goiania), where an interim storage was constructed. Soil samples collected from the 57 th Street (Goiania) and from the interim storage permitted to determine, through static method, the cesium distribution coefficent for different cesium solution concentrations. Those results allows for some migration/retention evaluations in disposal site selection. Some soils parameters (water content, density, granulometric analysis etc) as well as clay minerals constituents were also determined. (author) [pt

  14. Crown bridged thiacalix[4]arenes as cesium-selective ionophores in solvent polymeric membrane electrodes

    International Nuclear Information System (INIS)

    Bereczki, Robert; Csokai, Viktor; Gruen, Alajos; Bitter, Istvan; Toth, Klara

    2006-01-01

    Novel 1,3-alternate thiacalix[4]mono- and biscrown-6 ethers were studied as ionophores in poly(vinyl chloride) membrane electrodes. Their selectivity behavior was characterized with respect to large number of cations, including potential interferents in environmental samples, and the membrane composition was optimized for cesium ion response. Among the ionophores, 1,3-alternate thiacalix[4]mono(crown-6) ether showed, especially high selectivity for cesium over other alkali-metal ions. Transition and heavy metal ions did not interfere seriously with the electrode response, which indicates that the bridging sulfur atoms do not take part in the ion recognition process. The potentiometric cesium responses of all electrodes involved in this study were found close to Nernstian and the detection limits were lower than 10 -7 M. The Cs + /Na + selectivity of the different ionophore-based sensors and the solvent extraction ability of the ligands were interpreted based on the respective constants of complex formation

  15. Cesium and Strontium Specific Exchangers for Nuclear Waste Effluent Remediation

    International Nuclear Information System (INIS)

    Clearfield, A.; Bortun, A. I.; Bortun, L. A.; Bhlume, E. A.; Sylvester, P.; Graziano, G. M.

    2000-01-01

    During the past 50 years, nuclear defense activities have produced large quantities of nuclear waste that now require safe and permanent disposal. The general procedure to be implemented involves the removal of cesium and strontium from the waste solutions for disposal in permanently vitrified media. This requires highly selective sorbents or ion exchangers. Further, at the high radiation doses present in the solution, organic exchangers or sequestrants are likely to decompose over time. Inorganic ion exchangers are resistant to radiation damage and can exhibit remarkably high selectivities. We have synthesized three families of tunnel-type ion exchangers. The crystal structures of these compounds as well as their protonated phases, coupled with ion exchange titrations, were determined and this information was used to develop an understanding of their ion exchange behavior. The ion exchange selectivities of these phases could be regulated by isomorphous replacement of the framework metals by larger or smaller radius metals. In the realm of layered compounds, we prepared alumina, silica, and zirconia pillared clays and sodium micas. The pillared clays yielded very high Kd values for Cs+ and were very effective in removing Cs+ from groundwaters. The sodium micas also had a high affinity for Cs+ but an even greater attraction for S42+. They also possess the property of trapping these ions permanently as the layers slowly decrease their interlayer distance as loading occurs. Sodium nonatitanate exhibited extremely high Kd values for Sr2+ in alkaline tank wastes and should be considered for removal of Sr2+ in such cases. For tank wastes containing complexing agents, we have found that adding Ca2+ to the solution releases the complexed Sr2+ which may then be removed with the CST exchanger

  16. 3D Planetary Data Visualization with CesiumJS

    Science.gov (United States)

    Larsen, K. W.; DeWolfe, A. W.; Nguyen, D.; Sanchez, F.; Lindholm, D. M.

    2017-12-01

    Complex spacecraft orbits and multi-instrument observations can be challenging to visualize with traditional 2D plots. To facilitate the exploration of planetary science data, we have developed a set of web-based interactive 3D visualizations for the MAVEN and MMS missions using the free CesiumJS library. The Mars Atmospheric and Volatile Evolution (MAVEN) mission has been collecting data at Mars since September 2014. The MAVEN3D project allows playback of one day's orbit at a time, displaying the spacecraft's position and orientation. Selected science data sets can be overplotted on the orbit track, including vectors for magnetic field and ion flow velocities. We also provide an overlay the M-GITM model on the planet itself. MAVEN3D is available at the MAVEN public website at: https://lasp.colorado.edu/maven/sdc/public/pages/maven3d/ The Magnetospheric MultiScale Mission (MMS) consists of one hundred instruments on four spacecraft flying in formation around Earth, investigating the interactions between the solar wind and Earth's magnetic field. While the highest temporal resolution data isn't received and processed until later, continuous daily observations of the particle and field environments are made available as soon as they are received. Traditional `quick-look' static plots have long been the first interaction with data from a mission of this nature. Our new 3D Quicklook viewer allows data from all four spacecraft to be viewed in an interactive web application as soon as the data is ingested into the MMS Science Data Center, less than one day after collection, in order to better help identify scientifically interesting data.

  17. All-cause mortality after drug-eluting stent implantation in African-Americans.

    Science.gov (United States)

    Poludasu, Shyam; Cavusoglu, Erdal; Khan, Waqas; Marmur, Jonathan D

    2008-12-01

    Recent studies have questioned the safety of drug-eluting stents because of a higher incidence of late stent thrombosis, raising the possibility that drug-eluting stents may be associated with an increased mortality. The effect of drug-eluting stents on mortality in African-Americans is unknown. We evaluated 628 African-American patients (354 patients treated with drug-eluting stents and 274 patients treated with bare metal stents) between January 2003 and August 2005, using data from our bolus-only platelet glycoprotein IIb/IIIa inhibitor database. The primary end point was all-cause mortality obtained using social security death index. After a mean follow-up of 3+/-0.9 years, the mortality rate in the bare metal stents group was 12.8% compared with 7.1% in the drug-eluting stents group [adjusted P value=0.19; hazard ratio (HR) for bare metal stents group compared with drug-eluting stents group for death=1.4; 95% confidence interval (CI): 0.8-2.4]. In a subgroup analysis, patients presenting with acute coronary syndrome had a higher mortality when treated with bare metal stents compared with drug-eluting stents (17.1 vs. 6.3%, P=0.022; HR=2.2; 95% CI: 1.1-4.4). Patients with chronic kidney disease (all patients with creatinine >1.5 mg/dl) also had a higher mortality with bare metal stents compared with drug-eluting stents (36.7 vs. 20.4%, P=0.044; HR=2.3; 95% CI: 1.02-5.2). Drug-eluting stents seem to be safe in African-Americans and may improve survival in certain subgroups such as patients with acute coronary syndromes and chronic kidney disease.

  18. Cesium removal from liquid acidic wastes with the primary focus on ammonium molybdophosphate as an ion exchanger: A literature review

    International Nuclear Information System (INIS)

    Miller, C.J.

    1995-03-01

    Many articles have been written concerning the selective removal of cesium from both acidic and alkaline defense wastes. The majority of the work performed for cesium removal from defense wastes involves alkaline feed solutions. Several different techniques for cesium removal from acidic solutions have been evaluated such as precipitation, solvent extraction, and ion exchange. The purpose of this paper is to briefly review various techniques for cesium removal from acidic solutions. The main focus of the review will be on ion exchange techniques, particularly those involving ammonium molybdophosphate as the exchanger. The pertinent literature sources are condensed into a single document for quick reference. The information contained in this document was used as an aid in determining techniques to evaluate cesium removal from the acidic Idaho Chemical Processing Plant waste matrices. 47 refs., 2 tabs

  19. Forcing Cesium into Higher Oxidation States Using Useful hard x-ray Induced Chemistry under High Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Sneed, D.; Pravica, M.; Kim, E.; Chen, N.; Park, C.; White, M.

    2017-10-01

    This paper discusses our attempt to synthesize higher oxidation forms of cesium fluoride by pressurizing cesium fluoride in a fluorine-rich environment created via the x-ray decomposition of potassium tetrafluoroborate. This was done in order to confirm recent theoretical predictions of higher oxidation forms of CsFn. We discuss the development of a technique to produce molecular fluorine in situ via useful hard x-ray photochemistry, and the attempt to utilize this technique to form higher oxidation states of cesium fluoride. In order to verify the formation of the novel stoichiometric species of CsFn. X-ray Absorption Near Edge Spectroscopy (XANES) centered on the cesium K-edge was performed to probe the oxidation state of cesium as well as the local molecular coordination around Cs.

  20. Cesium removal from liquid acidic wastes with the primary focus on ammonium molybdophosphate as an ion exchanger: A literature review

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C.J.

    1995-03-01

    Many articles have been written concerning the selective removal of cesium from both acidic and alkaline defense wastes. The majority of the work performed for cesium removal from defense wastes involves alkaline feed solutions. Several different techniques for cesium removal from acidic solutions have been evaluated such as precipitation, solvent extraction, and ion exchange. The purpose of this paper is to briefly review various techniques for cesium removal from acidic solutions. The main focus of the review will be on ion exchange techniques, particularly those involving ammonium molybdophosphate as the exchanger. The pertinent literature sources are condensed into a single document for quick reference. The information contained in this document was used as an aid in determining techniques to evaluate cesium removal from the acidic Idaho Chemical Processing Plant waste matrices. 47 refs., 2 tabs.

  1. Radioactive fallout cesium in sewage sludge ash produced after the Fukushima Daiichi nuclear accident.

    Science.gov (United States)

    Kozai, Naofumi; Suzuki, Shinichi; Aoyagi, Noboru; Sakamoto, Fuminori; Ohnuki, Toshihiko

    2015-01-01

    The radioactive fallout cesium (¹³⁷Cs) in the sewage sludge ashes (SSAs) produced in Japan after the Fukushima Daiichi Nuclear Accident was tested. Five samples of SSAs produced in 2011 and 2012 were tested. Two of the samples contained ¹³⁷Cs (23 and 9.6 kBq/kg, respectively) above the radioactivity criterion (8 kBq of radioactive Cs/kg of solid) for controlled landfill disposal in Japan. The mineral components of SSA are roughly divided into two groups: an HCl-soluble phase mainly composed of phosphates and oxides; and silicates, including quartz, feldspar, and clay. Both phases contained ¹³⁷Cs. The majority (up to 90%) of ¹³⁷Cs was contained in the HCl-soluble phase. Among the HCl-soluble subphases, Fe-bearing phases that were probably iron oxides were mainly responsible for ¹³⁷Cs retention. No positive evidence was obtained that showed that phosphate-bearing phases, which were included most in SSAs along with the silicate phase, retained ¹³⁷Cs. Pre-pulverizing SSAs and heating them at 95 °C in a 6 M or a concentrated aqueous HCl was the most effective method of dissolving the HCl-soluble phase. The radioactivity concentrations of ¹³⁷Cs in all the HCl-treatment residues were below the radioactivity criterion. This residue was mostly composed of silicates. After static leaching tests of the residue at 60 °C for 28 days, no ¹³⁷Cs was detected in simulated environmental water leachates (pure water and synthetic seawater), demonstrating that 137Cs in the residue is very stably immobilized in the silicates.

  2. Selecting and applying cesium-137 conversion models to estimate soil erosion rates in cultivated fields.

    Science.gov (United States)

    Li, Sheng; Lobb, David A; Tiessen, Kevin H D; McConkey, Brian G

    2010-01-01

    The fallout radionuclide cesium-137 ((137)Cs) has been successfully used in soil erosion studies worldwide. However, discrepancies often exist between the erosion rates estimated using various conversion models. As a result, there is often confusion in the use of the various models and in the interpretation of the data. Therefore, the objective of this study was to test the structural and parametrical uncertainties associated with four conversion models typically used in cultivated agricultural landscapes. For the structural uncertainties, the Soil Constituent Redistribution by Erosion Model (SCREM) was developed and used to simulate the redistribution of fallout (137)Cs due to tillage and water erosion along a simple two-dimensional (horizontal and vertical) transect. The SCREM-predicted (137)Cs inventories were then imported into the conversion models to estimate the erosion rates. The structural uncertainties of the conversion models were assessed based on the comparisons between the conversion-model-estimated erosion rates and the erosion rates determined or used in the SCREM. For the parametrical uncertainties, test runs were conducted by varying the values of the parameters used in the model, and the parametrical uncertainties were assessed based on the responsive changes of the estimated erosion rates. Our results suggest that: (i) the performance/accuracy of the conversion models was largely dependent on the relative contributions of water vs. tillage erosion; and (ii) the estimated erosion rates were highly sensitive to the input values of the reference (137)Cs level, particle size correction factors and tillage depth. Guidelines were proposed to aid researchers in selecting and applying the conversion models under various situations common to agricultural landscapes.

  3. An Integrated Hydrologic Modeling Approach to Cesium-137 Transport in Forested Fukushima Watersheds

    Science.gov (United States)

    Siirila-Woodburn, E. R.; Steefel, C. I.; Williams, K. H.; Birkholzer, J. T.

    2015-12-01

    The 2011 Fukushima Daiichi Nuclear Power Plant (FDNPP) accident in Japan resulted in a significant dissemination of cesium-137 (Cs-137) over a wide area west of the plant, including the contamination of many watersheds and the subsequent evacuation of many communities. Today approximately 90% of on-land Cs-137 fallout following the accident resides in the upper 5 cm of forest soils. While this can be partially attributed to the forested composition of the prefecture (70%), there is also difficulty in cleanup efforts in these regions due to a lack of understanding and predictive capability of radioisotopes transport at the catchment to watershed scale. Subsequently, there is an uncertain, but likely long-term impact on local communities with implications for the use of nuclear energy use worldwide. Due to the complex nature of forest eco-hydrology, sophisticated modeling tools to accurately predict Cs-137 fluxes across different spatial and temporal scales are required. High fidelity, high resolution numerical modeling techniques in conjunction with parallel high performance computing is required to accurately determine transport and feedbacks in these complex systems. To better understand the fundamental transport of Cs-137, a watershed near the FDNPP is modeled with an integrated hydrologic model that includes variably saturated groundwater and overland flow in addition to atmospheric and vegetative processes via a coupled land surface model. Of specific interest is the impact of land cover type on hydrologic flow in the area, which will likely play an important role in erosion patterns and the consequent transport of Cs-137 strongly sorbed to surface soils. Risk management practices (for example, passive remediation versus active remediation such as targeted logging) for two principal tree types (evergreen and deciduous) are informed given the simulated responses to flow patterns assuming different quantities and spatial distribution patterns of each tree type.

  4. Cesium removal from high-pH, high-salt wastwater using crystalline silicotitanate sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Walker, J.F. Jr.; Taylor, P.A.; Lee, D.D.

    1997-11-01

    Treatment and disposal options for Department of Energy (DOE) underground storage tank waste at Hanford, Savannah River, and Oak Ridge National Laboratory (ORNL) are limited by high gamma radiation fields that are produced by high concentrations of cesium in the waste. Treatment methods are needed to remove the cesium from the liquid waste and thus concentrate the cesium into high-activity, remote-handled waste forms. The treated liquids could then be processed and disposed of by more cost-effective means with less radiation exposure to workers. A full-scale demonstration of one cesium removal technology is currently being conducted at ORNL. This demonstration utilizes a modular, mobile ion-exchange system and existing facilities for the off-gas system, secondary containment, and utilities. The ion-exchange material, crystalline silicotitanate (CST), was chosen on the basis of its effectiveness in laboratory tests. The CST, which was developed through a Cooperative Research and Development Agreement between DOE and private industry, has several advantages over current organic ion-exchange technologies. These advantages include (1) the ability to remove cesium in the presence of high concentrations of potassium, (2) a high affinity for cesium in both alkaline and acidic conditions, (3) physical stability over wide alkaline and acidic ranges, and (4) the elimination of large volumes of secondary waste required for regeneration of organic ion exchangers. Approximately 100,000 L of wastewater will be processed during the demonstration. The wastewater being processed has a high salt content, about 4 M NaNO{sub 3}, and a pH of 12 to 13. This paper discusses the results of the full-scale demonstration and compares these results with data from the laboratory tests.

  5. Metabolism of 137cesium, 137barium in the rat. Therapeutics of the contamination

    International Nuclear Information System (INIS)

    Remy, J.; Philippon, A.; Lafuma, J.; Walter, C.

    1967-01-01

    The authors carry out research into the distribution kinetics, the metabolism and the excretion of 137 Cs - 137 Ba in the rat. They show that these phenomena are independent of the method of applying a single dose. The distribution tends to adopt in all cases a typical shape which remains the same depending on the body burden. Biological analysis of the state of the cesium in the biological media shows that it is transported in the free and ionised form. Considering the problem of the method of penetration of the cesium ion in the intracellular medium, and in particular by the in vivo and in vitro kinetic study of the plasma - red cell system, the authors make the assumption that an active transport of cesium occurs by the cell membrane. They thus arrive at an overall picture of the cesium distribution in the organism which is essentially characterized by a dynamic distribution equilibrium between two compartments: 99 per cent of the cesium accumulates in the intracellular pool, 1 per cent in the extracellular liquids. This latter compartment is open to the emunctories. Because, of the active transport by the cell membranes, the intracellular pool is filled rapidly but discharge is slow. This phenomenon is the limiting factor in the decrease of the body burden. From this representation, the authors deduce the reasons for the relative failure of the various therapeutic methods examined up till now by themselves or by other authors. The stimulation of the natural emunctories in the case of diuretics for example, can only improve the purification of the extracellular compartment. Now this latter contains only 1 per cent of the body burden and recharging is slow. Furthermore the methods designed to counteract or inhibit the active transport of cesium by the cell membrane are still at the present time incompatible with the survival of the cell. (authors) [fr

  6. Increasing flexibility in two-dimensional liquid chromatography by pulsed elution of the first dimension

    DEFF Research Database (Denmark)

    Jakobsen, Simon S.; Christensen, Jan H.; Verdier, Sylvain

    2017-01-01

    This work demonstrates the development of an online two-dimensional liquid chromatography (2D-LC) method where the first dimension column is eluted by a sequence of pulses of increasing eluotropic strength generated by the LC pumps (pulsed-elution 2D-LC). Between the pulses, the first dimension...... online comprehensive 2D-LC: undersampling, difficulties in refocusing, and lack of flexibility in the selection of column dimensions and flow rates because the two dimensions constrain each other. The pulsed-elution 2D-LC was applied for the analysis of a basic fraction of vacuum gas oil. Peak capacity...

  7. Porous Polymer Drug-Eluting Coating Prepared by Radiation Induced Polymerization

    International Nuclear Information System (INIS)

    Veres, M.; Tóth, S.; Koós, M.; Beiler, B.

    2009-01-01

    Drug-eluting stents have several advantages over bare metal implants. They eliminate restenosis, the main drawback of bare metal stents. In addition the locally delivered drug is more effective and causes less side-effects. However in some cases dangerous stent thrombosis, inflammatory and allergy reactions were observed after their implantation, which first of all related to the drug-eluting coating. This project is aimed to develop a novel biocompatible nanoporous polymer layer by radiation induced polymerization that is capable of holding and eluting drugs and promotes endothelization after the release of the drug. (author)

  8. Porous orthopedic steel implant as an antibiotic eluting device: prevention of post-surgical infection on an ovine model.

    Science.gov (United States)

    Gimeno, Marina; Pinczowski, Pedro; Vázquez, Francisco J; Pérez, Marta; Santamaría, Jesús; Arruebo, Manuel; Luján, Lluís

    2013-08-16

    Traumatology and orthopedic surgery can benefit from the use of efficient local antibiotic-eluting systems to avoid bacterial contamination of implanted materials. In this work a new percutaneous porous-wall hollow implant was successfully used as a local antibiotic-eluting device both in vitro and in vivo. The implant is a macroporous 316 L stainless steel filter tube with a nominal filtration cut-off size of 200 nm with one open end which was used to load the synthetic antibiotic linezolid and an opposite blind end. The antibiotic release kinetics from the device on a simulated biological fluid under in vitro conditions demonstrated an increased concentration during the first five days that subsequently was sustained for at least seven days, showing a kinetic close to a zero order release. Antibiotic-loaded implants were placed in the tibia of four sheep which were trans-surgically experimentally infected with a biofilm forming strain of Staphylococcus aureus. After 7 and 9 days post infection, sheep did not show any evidence of infection as demonstrated by clinical, pathological and microbiological findings. These results demonstrate the capability of such an antibiotic-loaded implant to prevent infection in orthopedic devices in vivo. Further research is needed to assess its possible use in traumatology and orthopedic surgery. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. Determining and correcting "moment bias" in gradient polymer elution chromatography.

    Science.gov (United States)

    Striegel, André M

    2003-05-09

    Gradient polymer elution chromatography (GPEC) is rapidly becoming the analytical method of choice for determining the chemical composition distribution (CCD) of synthetic polymers. GPEC can be performed in traditional (strict precipitation-redissolution mechanism) or interactive (normal- and reversed-phase) modes, and results may be qualitative, semi-quantitative, or fully quantitative. Quantitative approaches have thus far relied on colligative or end group techniques for determining the values of standards used in constructing the GPEC calibration curve. While the values obtained from said methods are number-averages, they are assigned to the peak apexes of the standards (i.e. assigned as peak averages). This creates a determinate error in the quantitation, referred to herein as "moment bias". In this paper we determine moment bias for a series of styrene-acrylonitrile (SAN) copolymers, where the distribution and averages of the AN% have been measured using normal-phase (NP) GPEC. We also correct for the effect via statistical treatment of the chromatographic data.

  10. Fragments of protein A eluted during protein A affinity chromatography.

    Science.gov (United States)

    Carter-Franklin, Jayme N; Victa, Corazon; McDonald, Paul; Fahrner, Robert

    2007-09-07

    Protein A affinity chromatography is a common method for process scale purification of monoclonal antibodies. During protein A affinity chromatography, protein A ligand co-elutes with the antibody (commonly called leaching), which is a potential disadvantage since the leached protein A may need to be cleared for pharmaceutical antibodies. To determine the mechanism of protein A leaching and characterize the leached protein A, we fluorescently labeled the protein A ligand in situ on protein A affinity chromatography media. We found that intact protein A leaches when loading either purified antibody or unpurified antibody in harvested cell culture fluid (HCCF), and that additionally fragments of protein A leach when loading HCCF. The leaching of protein A fragments can be reduced by EDTA, suggesting that proteinases contribute to the generation of protein A fragments. We found that protein A fragments larger than about 6000 Da can be measured by enzyme linked immunosorbent assay, and that they can be more difficult to clear than whole protein A by cation-exchange chromatography.

  11. Summary of cesium-137 sludge irradiation activities in the United States

    Science.gov (United States)

    Sivinski, J.; Ahlstrom, S.

    Research initiated in 1975 has demonstrated that cesium-137 is an effective isotope for reducing pathogens in sewage sludge to levels where reuse of the material in public areas meets criteria for protection of the public health. Complementary research has demonstrated the value of the irradiated sludge in both agronomic and animal science applications. A 7,250 kg/day cesium-137 sludge irradiator is operating at Sandia National Laboratories. A full-scale facility will be constructed and operated by the City of Albuquerque, New Mexico to disinfect the City's sludge prior to reuse.

  12. Sensitivity of cesium chemistry to the O/U radio in UO2+x

    International Nuclear Information System (INIS)

    McFarlane, J.; LeBlanc, J.C.; Owen, D.G.

    1995-01-01

    The effect of O/U ratio on chemical reactivity was investigated in a cesium-iodide/uranium/tungsten system at temperatures up to 2200 K. It was found that slight changes in the oxidation of the urania had a large effect on reactivity. Crushed fresh fuel samples showed little reaction with CsI; however, slightly hyperstoichiometric fuel showed considerable reaction. The tungsten participated in the reaction by removing excess oxygen from the urania, eventually leading to a cesium tungstate species that was analyzed by Fourier Transform Infrared (FTIR) and X-ray diffraction (XRD) techniques. (author)

  13. Strontium and cesium extraction into hydrocarbons using alkyl cobalt dicarbollide and polyethylene glycols

    International Nuclear Information System (INIS)

    Chamberlin, R.M.; Abney, K.D.

    1999-01-01

    The extraction of strontium and cesium ions from high ionic strength acid, base, and salt solutions into an organic extractant consisting of alkyl cobalt dicarbollide and polyethylene glycol (PEG) in diethylbenzene was investigated. Adding hexaethylene glycol or PEG-400 improved the strontium extraction ≥ 100-fold, while cesium extraction was decreased at high PEG concentrations. The extractions are rapid and selective, even in the presence of molar concentrations of sodium ion, suggesting that alkyl cobalt dicarbollide extractants are useful for the treatment of alkaline nuclear wastes. A method for the synthesis of tetra-n-hexyl(cobalt dicarbollide) is described. (author)

  14. Decision document for the final disposition of cesium and strontium capsules

    Energy Technology Data Exchange (ETDEWEB)

    Claghorn, R.D., Fluor Daniel Hanford

    1997-03-01

    This report was prepared to document decisions regarding the disposition of cesium and strontium capsules. A Decision Support Board was established to consider the multiple drivers for decisions regarding disposition of cesium and strontium capsules and make decisions that form the near-term guidance for the project. The decision process included several Decision Board meetings, documented in this report, in which technical and programmatic information was presented by Tank Waste Remediation System (TWRS) technical staff and considered by the Decision Board. The process also included preparation of the decision documentation, which is presented in this report.

  15. Deviation from local thermodynamic equilibrium in a cesium-seeded argon plasma

    International Nuclear Information System (INIS)

    Stefanov, B.; Zarkova, L.

    1985-11-01

    The possibility of deviations from local thermodynamic equilibrium of a cesium seeded argon plasma has been analyzed. A four level model of cesium has been employed. Overpopulations of the ground state and the first excited state as well as the corresponding reduction of the electron density are calculated for cylindrical discharge structures by solving stationary rate equations. Numerical results are presented. These results indicate that in a large regime of plasma conditions the LTE assumption is valid for electron temperatures larger than 3000 K. (orig.)

  16. On-Chip Microplasmas for the Detection of Radioactive Cesium Contamination in Seawater

    Directory of Open Access Journals (Sweden)

    Joshua B. Joffrion

    2017-08-01

    Full Text Available On-chip microplasmas have previously been used in designing a compact and portable device for identifying pollutants in a water sample. By exciting a liquid sample with a high energy microdischarge and recording the spectral wavelengths emitted, the individual elements in the liquid are distinguishable. In particular, this study focuses on cesium, a contaminant from nuclear incidents such as the collapse of the nuclear power plant in Fukushima, Japan. This article shows that not only can the presence of cesium be clearly determined at concentrations as low as 10 ppb, but the relative concentration contained in the sample can be determined through the discharges’ relative spectral intensity.

  17. Heat Transfer During Evaporation of Cesium From Graphite Surface in an Argon Environment

    Directory of Open Access Journals (Sweden)

    Bespala Evgeny

    2016-01-01

    Full Text Available The article focuses on discussion of problem of graphite radioactive waste formation and accumulation. It is shown that irradiated nuclear graphite being inalienable part of uranium-graphite reactor may contain fission and activation products. Much attention is given to the process of formation of radioactive cesium on the graphite element surface. It is described a process of plasma decontamination of irradiated graphite in inert argon atmosphere. Quasi-one mathematical model is offered, it describes heat transfer process in graphite-cesium-argon system. Article shows results of calculation of temperature field inside the unit cell. Authors determined the factors which influence on temperature change.

  18. Release of tellurium and cesium from UO2 in LWR fuel rods during irradiation

    International Nuclear Information System (INIS)

    Malen, K.A.

    1983-01-01

    In this paper the release of tellurium (Te-132) and cesium (Cs-134 and Cs-137) from UO 2 -fuel is analyzed. The basis for the analysis is the experimental results from the S176 series of experiments performed at Studsvik. It seems that the model developed earlier for release of iodine applies also to tellurium and cesium. This model assumes sweeping up of the species in question by moving grain boundaries and subsequent release through grain boundary porosity. An interesting extra feature is deposition of tellurium at temperatures in the range 1500-2000 K believed to be due to condensation. (author)

  19. Study of the removal of cesium from aqueous solutions by graphene oxide

    International Nuclear Information System (INIS)

    Bueno, Vanessa N.; Rodrigues, Debora F.; Vitta, Patricia B. Di

    2013-01-01

    Graphene oxide, used in this work, was synthesized from the oxidation of graphite by Hummer method. The experiments were performed in batch and analyzed for the following parameters: contact time, pH, cesium ion concentration in aqueous solution and removing capacity of the graphene oxide. After the experiments the samples were vacuum filtered and the remaining cesium in solution was quantified by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The equilibrium was reached after 60 minutes of contact in neutral solution. The percentage of removal was around 80%

  20. Alkali-iodide/urania systems at high temperatures. 1. Cesium uranate chemistry

    International Nuclear Information System (INIS)

    McFarlane, J.; LeBlanc, J.C.

    1994-09-01

    Uranate compounds are likely to form in irradiated fuel from the reaction between UO 2 and fission products along UO 2 grain boundaries and in the fuel-cladding gap. Literature on the high-temperature chemistry of cesium and rubidium uranates was reviewed. Results from Knudsen cell experiments from 900 to 2600 K on cesium uranates are discussed. These studies indicate that the uranate phases formed depend on the oxygen potential of the system, which varies with the composition of the condensed phase. 62 refs., 12 figs., 6 tabs., 2 appendices

  1. Psychological and mobile evaluation of intra-uterus children exposed to the radiation with cesium-137

    International Nuclear Information System (INIS)

    Ferreira, Celia Marly

    1995-01-01

    The presented work had as objective the accomplishment of a comparative study of cesium-137 radioactive element effects in the psychological and motor development of children which were going submitted the intra-uterus irradiation during the chronological age of three years. The comparison of the results of study is done through a group-control composed for five children without any involvement with the cesium-137 accident - occurred in 1987 in Goiania, Brazil - of same social, economic and cultural level and with the same age of the reached

  2. Analysis method of fractional release of cesium from fuel elements of HTTR

    International Nuclear Information System (INIS)

    Sawa, Kazuhiro; Okamoto, Futoshi; Shiozawa, Shusaku; Sasaki, Katsunori.

    1990-03-01

    This report describes an analytical model and parameters to evaluate the fractional release of metallic fission product (cesium) during normal operation of High Temperature Engineering Test Reactor (HTTR). The fractional releases, which are calculated by TRAFIC code, on the basis of the present analytical model and parameters show about ten times larger than that measured in the sweep gas capsule irradiation test and the OGL-1 fuel element irradiation test. Thus, the analytical model and the parameters are concluded to be applicable to the evaluation of the cesium release from the HTTR fuel element in the safety analysis. (author)

  3. Transfer of radio-cesium from forest soil to woodchips using fungal activities

    Science.gov (United States)

    Kaneko, Nobuhiro; Huang, Yao; Tanaka, Yoichiro; Fujiwara, Yoshihiro; Sasaki, Michiko; Toda, Hiroto; Takahashi, Terumasa; Kobayashi, Tatsuaki; Harada, Naoki; Nonaka, Masahiro

    2014-05-01

    Raido-cesium released to terrestrial ecosystems by nuclear accidents is know to accumulate forest soil and organic layer on the soil. Forests in Japan are not exceptions. Practically it is impossible to decontaminate large area of forests. However, there is a strong demand from local people, who has been using secondary forests (Satoyama) around croplands in hilly areas, to decontaminate radio-cesium, because those people used to collect wild mushrooms and edible plants, and there are active cultures of mushrooms using logs and sawdusts. These natural resource uses consist substantial part of their economical activities, Therefore it is needed to decontaminate some selected part of forests in Japan to local economy. Clear cutting and scraping surface soil and organic matter are common methods of decontamination. However the efficiency of decontamination is up to 30% reduction of aerial radiation, and the cost to preserve contaminated debris is not affordable. In this study we used wood chips as a growth media for saprotrophic fungi which are known to accumulate redio-cesium. There are many studies indicated that mushrooms accumulated redio-cesium from forest soil and organic layer. It is not practical to collect mushrooms to decontaminate redio-cesium, because biomass of mushrooms are not enough to collect total contaminants. Mushrooms are only minor part of saprotrophic fungi. Fungal biomass in forest soil is about 1% of dead organic matter on forest floor. Our previous study to observe Cs accumulation to decomposing leaf litter indicated 18% absorption of total soil radio-Cs to litter during one year field incubation (Kaneko et al., 2013), and Cs concentration was proportional to fungal biomass on litter. This result indicated that fungi transferred radio-cesium around newly supplied leaf litter free of contamination. Therefore effective decontamination will be possible if we can provide large amount of growth media for saprotrophic fungi, and the media can be

  4. Production of bio-fuel ethanol from distilled grain waste eluted from Chinese spirit making process.

    Science.gov (United States)

    Tan, Li; Sun, Zhaoyong; Zhang, Wenxue; Tang, Yueqin; Morimura, Shigeru; Kida, Kenji

    2014-10-01

    Distilled grain waste eluted from Chinese spirit making is rich in carbohydrates, and could potentially serve as feedstock for the production of bio-fuel ethanol. Our study evaluated two types of saccharification methods that convert distilled grain waste to monosaccharides: enzymatic saccharification and concentrated H2SO4 saccharification. Results showed that enzymatic saccharification performed unsatisfactorily because of inefficient removal of lignin during pretreatment. Concentrated H2SO4 saccharification led to a total sugar recovery efficiency of 79.0 %, and to considerably higher sugar concentrations than enzymatic saccharification. The process of ethanol production from distilled grain waste based on concentrated H2SO4 saccharification was then studied. The process mainly consisted of concentrated H2SO4 saccharification, solid-liquid separation, decoloration, sugar-acid separation, oligosaccharide hydrolysis, and continuous ethanol fermentation. An improved simulated moving bed system was employed to separate sugars from acid after concentrated H2SO4 saccharification, by which 95.8 % of glucose and 85.8 % of xylose went into the sugar-rich fraction, while 83.3 % of H2SO4 went into the acid-rich fraction. A flocculating yeast strain, Saccharomyces cerevisiae KF-7, was used for continuous ethanol fermentation, which produced an ethanol yield of 91.9-98.9 %, based on glucose concentration.

  5. Adsorptive removal of cesium using bio fuel extraction microalgal waste

    International Nuclear Information System (INIS)

    Inoue, Katsutoshi; Gurung, Manju; Adhikari, Birendra Babu; Alam, Shafiq; Kawakita, Hidetaka; Ohto, Keisuke; Kurata, Minoru; Atsumi, Kinya

    2014-01-01

    Highlights: • A novel biosorbent was prepared from the microalgal waste after biofuel extraction. • Higher selectivity and adsorption efficiency of the adsorbent for Cs + over Na + ions from aqueous solutions. • Potential candidate and eco-friendly alternative to the commercial resins such as zeolite. - Abstract: An adsorption gel was prepared from microalgal waste after extracting biodiesel oil by a simple chemical treatment of crosslinking using concentrated sulfuric acid. The adsorbent exhibited notably high selectivity and adsorption capacity towards Cs + over Na + from aqueous solutions, within the pH range of slightly acidic to neutral. The adsorption followed Langmuir isotherm and the maximum adsorption capacity of the gel for Cs + calculated from Langmuir model was found to be 1.36 mol kg −1 . Trace concentration of Cs + ions present in aqueous streams was successfully separated from Na + ions using a column packed with the adsorbent at pH 6.5. The adsorption capacity of the gel towards Cs + in column operation was 0.13 mol kg −1 . Although the adsorbed Cs + ions were easily eluted using 1 M hydrochloric acid solution, simple incineration is proposed as an alternative for the treatment of adsorbent loaded with radioactive Cs + ions due to the combustible characteristics of this adsorbent

  6. Adsorptive removal of cesium using bio fuel extraction microalgal waste.

    Science.gov (United States)

    Inoue, Katsutoshi; Gurung, Manju; Adhikari, Birendra Babu; Alam, Shafiq; Kawakita, Hidetaka; Ohto, Keisuke; Kurata, Minoru; Atsumi, Kinya

    2014-04-30

    An adsorption gel was prepared from microalgal waste after extracting biodiesel oil by a simple chemical treatment of crosslinking using concentrated sulfuric acid. The adsorbent exhibited notably high selectivity and adsorption capacity towards Cs(+) over Na(+) from aqueous solutions, within the pH range of slightly acidic to neutral. The adsorption followed Langmuir isotherm and the maximum adsorption capacity of the gel for Cs(+) calculated from Langmuir model was found to be 1.36 mol kg(-1). Trace concentration of Cs(+) ions present in aqueous streams was successfully separated from Na(+) ions using a column packed with the adsorbent at pH 6.5. The adsorption capacity of the gel towards Cs(+) in column operation was 0.13 mol kg(-1). Although the adsorbed Cs(+) ions were easily eluted using 1M hydrochloric acid solution, simple incineration is proposed as an alternative for the treatment of adsorbent loaded with radioactive Cs(+) ions due to the combustible characteristics of this adsorbent. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Transport of the radioisotopes iodine-131, cesium-134, and cesium-137 from the fallout following the accident at the Chernobyl nuclear reactor into cheesemaking products

    International Nuclear Information System (INIS)

    Assimakopoulos, P.A.; Ioannides, K.G.; Pak; Paradopoulou, C.V.

    1987-01-01

    The transport of radiation contamination from milk to products of the cheese making process has been studied. The concentration of radioactive iodine and cesium in samples of sheep milk and cheese (Gruyere) products was measured for 10 consecutive production d. Milk with concentration 100 Bq/L in each of the radionuclides 131 I, 134 Cs, and 137 Cs cheese with concentration 82.2 +/- 3.9 Bq/kg in iodine and an average of 42.3 +/- 2.3 Bq/kg in the cesium isotopes is produced. The corresponding concentrations in cream extracted from the same milk are 26.7 +/- 2.8 Bq/kg ( 131 I) and 18.6 +/- 1.9 Bq/kg ( 134 Cs, 137 Cs)

  8. Optimization of elution salt concentration in stepwise elution of protein chromatography using linear gradient elution data. Reducing residual protein A by cation-exchange chromatography in monoclonal antibody purification.

    Science.gov (United States)

    Ishihara, Takashi; Kadoya, Toshihiko; Endo, Naomi; Yamamoto, Shuichi

    2006-05-05

    Our simple method for optimization of the elution salt concentration in stepwise elution was applied to the actual protein separation system, which involves several difficulties such as detection of the target. As a model separation system, reducing residual protein A by cation-exchange chromatography in human monoclonal antibody (hMab) purification was chosen. We carried out linear gradient elution experiments and obtained the data for the peak salt concentration of hMab and residual protein A, respectively. An enzyme-linked immunosorbent assay was applied to the measurement of the residual protein A. From these data, we calculated the distribution coefficient of the hMab and the residual protein A as a function of salt concentration. The optimal salt concentration of stepwise elution to reduce the residual protein A from the hMab was determined based on the relationship between the distribution coefficient and the salt concentration. Using the optimized condition, we successfully performed the separation, resulting in high recovery of hMab and the elimination of residual protein A.

  9. Cesium 137 and cesium 134 in roe deer from the north and central Hessen area: Measurement of the contamination in muscle tissue after the Chernobyl accident

    International Nuclear Information System (INIS)

    Georgii, S.; Brunn, H.; Eskens, U.

    1989-01-01

    The present report describes the amount of incorporated 134 and 137 cesium in the muscle tissue of 330 roe deer, which were referred for routine necropsy between 1986 and 1988. The amount of incorporated radiocesium was markedly decreased in 1987 and 1988 compared with 1986. However, a seasonal fluctuation with increase of the measured incorporated radioactivity during the autumn months was observed in 1987 and 1988. (orig.) [de

  10. REUSABILITY OF BOND ELUT CERTIFY COLUMNS FOR THE EXTRACTION OF DRUGS FROM PLASMA

    NARCIS (Netherlands)

    CHEN, XH; FRANKE, JP; WIJSBEEK, J; DEZEEUW, RA

    1993-01-01

    The reusability of Bond Elut Certify columns for the extraction of toxicologically relevant drugs from plasma has been evaluated. Pentobarbital, hexobarbital, mepivacaine, trimipramine and clonazepam were selected as test drugs to represent various classes of drugs. The columns were regenerated

  11. Alendronate-Eluting Biphasic Calcium Phosphate (BCP) Scaffolds Stimulate Osteogenic Differentiation

    Science.gov (United States)

    Kim, Sung Eun; Lee, Deok-Won; Kang, Eun Young; Jeong, Won Jae; Lee, Boram; Jeong, Myeong Seon; Kim, Hak Jun; Park, Kyeongsoon; Song, Hae-Ryong

    2015-01-01

    Biphasic calcium phosphate (BCP) scaffolds have been widely used in orthopedic and dental fields as osteoconductive bone substitutes. However, BCP scaffolds are not satisfactory for the stimulation of osteogenic differentiation and maturation. To enhance osteogenic differentiation, we prepared alendronate- (ALN-) eluting BCP scaffolds. The coating of ALN on BCP scaffolds was confirmed by scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). An in vitro release study showed that release of ALN from ALN-eluting BCP scaffolds was sustained for up to 28 days. In vitro results revealed that MG-63 cells grown on ALN-eluting BCP scaffolds exhibited increased ALP activity and calcium deposition and upregulated gene expression of Runx2, ALP, OCN, and OPN compared with the BCP scaffold alone. Therefore, this study suggests that ALN-eluting BCP scaffolds have the potential to effectively stimulate osteogenic differentiation. PMID:26221587

  12. Alendronate-Eluting Biphasic Calcium Phosphate (BCP Scaffolds Stimulate Osteogenic Differentiation

    Directory of Open Access Journals (Sweden)

    Sung Eun Kim

    2015-01-01

    Full Text Available Biphasic calcium phosphate (BCP scaffolds have been widely used in orthopedic and dental fields as osteoconductive bone substitutes. However, BCP scaffolds are not satisfactory for the stimulation of osteogenic differentiation and maturation. To enhance osteogenic differentiation, we prepared alendronate- (ALN- eluting BCP scaffolds. The coating of ALN on BCP scaffolds was confirmed by scanning electron microscopy (FE-SEM, energy-dispersive X-ray spectroscopy (EDS, and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR. An in vitro release study showed that release of ALN from ALN-eluting BCP scaffolds was sustained for up to 28 days. In vitro results revealed that MG-63 cells grown on ALN-eluting BCP scaffolds exhibited increased ALP activity and calcium deposition and upregulated gene expression of Runx2, ALP, OCN, and OPN compared with the BCP scaffold alone. Therefore, this study suggests that ALN-eluting BCP scaffolds have the potential to effectively stimulate osteogenic differentiation.

  13. Analysis of LSD in human body fluids and hair samples applying ImmunElute columns.

    Science.gov (United States)

    Röhrich, J; Zörntlein, S; Becker, J

    2000-01-10

    Immunoaffinity extraction units (LSD ImmunElute) are commercially available for the analysis of lysergic acid diethylamide (LSD) in urine. The ImmunElute resin contains immobilized monoclonal antibodies to LSD. We applied the ImmunElute procedure to serum and also to human hair samples. For hair analysis the samples were first extracted with methanol under sonication. The extracts were then purified using the ImmunElute resin. LSD analysis was carried out with HPLC and fluorescence detection. The immunoaffinity extraction provides highly purified extracts for chromatographic analysis. The limit of detection (signal-to-noise ratio = 3) has been determined to be hair samples from drug abusers (n = 11). One of these samples tested positive with an amount of 110 pg LSD in 112 mg extracted hair corresponding to a concentration of 1 pg/mg.

  14. Mechanisms of Very Late Drug-Eluting Stent Thrombosis Assessed by Optical Coherence Tomography

    DEFF Research Database (Denmark)

    Taniwaki, Masanori; Radu, Maria D; Zaugg, Serge

    2016-01-01

    BACKGROUND: The pathomechanisms underlying very late stent thrombosis (VLST) after implantation of drug-eluting stents (DES) are incompletely understood. Using optical coherence tomography, we investigated potential causes of this adverse event. METHODS AND RESULTS: Between August 2010 and Decemb...

  15. Development of a probucol-releasing antithrombogenic drug eluting stent.

    Science.gov (United States)

    Vedantham, Kumar; Chaterji, Somali; Kim, Sung Won; Park, Kinam

    2012-05-01

    The success of drug eluting stents (DESs) has been challenged by the manifestation of late stent thrombosis after DES implantation. The incomplete regeneration of the endothelial layer poststenting triggers adverse signaling processes precipitating in thrombosis. Various approaches have been attempted to prevent thrombosis, including the delivery of biological agents, such as estradiol, that promote endothelialization, and the use of natural polymers as coating materials. The underlying challenge has been the inability to release the biological agent in synchronization with the temporal sequence of vascular wound healing in vivo. The natural healing process of the endothelium after an injury starts after a week and may take up to a month in humans. This article presents a novel DES formulation using a hemocompatible polyurethane (PU) matrix to sustain the release of probucol (PB), an endothelial agonist, by exploiting the greater difference in the solubility parameters of PB and PU. This results in the formation of crystalline PB aggregates retarding drug release from PU. The physicochemical properties of PB in PU were confirmed using differential scanning calorimetry and X-ray diffraction. Drug-polymer compatibility was examined using infrared spectral analysis. Also, in vitro studies using primary human aortic endothelial cells resulted in the selection of 5% w/w PB as the optimal dose, to be further tested in vitro and in vivo. This work develops and tests a promising new DES formulation to enable faster endothelial cell proliferation poststenting, potentially minimizing the incidence and severity of thrombotic events after DES implantation. Copyright © 2012 Wiley Periodicals, Inc.

  16. Elution of lead from lead zirconate titanate ceramics to acid rain

    Science.gov (United States)

    Tsurumi, Takaaki; Takezawa, Shuhei; Hoshina, Takuya; Takeda, Hiroaki

    2017-10-01

    The amount of lead that eluted from lead zirconate titanate (PZT) ceramics to artificial acid rain was evaluated. Four kinds of PZT ceramics, namely, pure PZT at MPB composition, CuO-added PZT, PZT with 10 mol % substitution of Ba for Pb, and CuO-added PZT with 10 mol % substitution of Ba for Pb, were used as samples of the elution test. These PZT ceramics of 8 mm2 and 1.1-1.2 mm thickness were suspended in 300 ml of H2SO4 solution of pH 4.0. The concentration of lead eluted from PZT was in the range from 0.2 to 0.8 ppm. It was found that both liquid phase formation by the addition of CuO and the substitution of Ba for Pb were effective to reduce the amount of lead that eluted. By fitting the leaching out curve with a classical equation, a master curve assuming no sampling effect was obtained. The lead concentration evaluated from the amount of lead that eluted from a commercial PZT plate to H2SO4 solution of pH 5.3 was almost the same as the limit in city water. It is concluded that PZT is not harmful to health and the environment and the amount of lead that eluted from PZT can be controlled by modifying PZT composition.

  17. Nonspecific native elution of proteins and mumps virus in immunoaffinity chromatography.

    Science.gov (United States)

    Brgles, Marija; Sviben, Dora; Forčić, Dubravko; Halassy, Beata

    2016-05-20

    Immunoaffinity chromatography, based on the antigen-antibody recognition, enables specific purification of any antigen (protein, virus) by its antibody. The problem with immunoaffinity chromatography is the harsh elution conditions required for disrupting strong antigen-antibody interactions, such as low pH buffers, which are often deleterious for the immobilized protein and the protein to be isolated since they can also disrupt the intramolecular forces. Therefore, immunoaffinity chromatography can only be partially used for protein and virus purification. Here we report on a nonspecific elution in immunoaffinity chromatography using native conditions by elution with amino acid solution at physiological pH for which we suppose possible competing mechanism of action. Elution potential of various amino acid solutions was tested using immunoaffinity columns specific for ovalbumin and mumps virus, and protein G affinity column. Results have shown that the most successful elution solutions were those containing imidazole and arginine of high molarity. Imidazole represents aromatic residues readily found at the antigen-antibody interaction surface and arginine is most frequently found on protein surface in general. Therefore, results on their eluting power in immunoaffinity chromatography, which increases with increasing molarity, are in line with the competing mechanism of action. Virus immunoaffinity chromatography resulted in removal on nonviable virus particles, which is important for research and biotechnology purposes. In addition, amino acids are proven stabilizers for proteins and viruses making approach presented in this work a very convenient purification method. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Dual cesium and rubidium atomic fountain with a 10-16 level accuracy and applications

    International Nuclear Information System (INIS)

    Chapelet, F.

    2008-05-01

    Atomic fountains are the most accomplished development of the atomic clocks based on the cesium atom whose hyperfine resonance defines the SI second since 1967. Today these systems are among those which realize the second with the best accuracy. We present the last developments of the cold cesium and rubidium atom dual fountain experiment at LNE-SYRTE. This unique dual setup would allow to obtain an outstanding resolution in fundamental physics tests based on atomic transition frequency comparisons. In order to enable operation with both atomic species simultaneously, we designed, tested and implemented on the fountain new collimators which combine the laser lights corresponding to each atom. By comparing our rubidium fountain to another cesium fountain over a decade, we performed a test of the stability of the fine structure constant at the level of 5 * 10 -16 per year. We carried on the work on the clock accuracy and we focused on the phase gradients effects in the interrogation cavity and on the microwave leakage. The fountain accuracy has been evaluated to 4 * 10 -16 for the cesium clock and to 5 * 10 -16 for the refurbished rubidium clock. As a powerful instrument of metrology, our fountain was implicated in many clock comparisons and contributed many times to calibrate the International Atomic Time. Furthermore, we used the fountain to perform a new test of Lorentz local invariance. (author)

  19. Physical barrier effect of geopolymeric waste form on diffusivity of cesium and strontium

    Energy Technology Data Exchange (ETDEWEB)

    Jang, J.G.; Park, S.M.; Lee, H.K., E-mail: haengki@kaist.ac.kr

    2016-11-15

    Highlights: • Physical immobilization of radionuclides in geopolymer was quantitatively assessed. • Fly ash-based geopolymer showed excellent immobilization performance. • Diffusivity of soluble Cs and Sr was highly correlated with critical pore diameter. - Abstract: The present study investigates the physical barrier effect of geopolymeric waste form on leaching behavior of cesium and strontium. Fly ash-based geopolymers and slag-blended geopolymers were used as solidification agents. The leaching behavior of cesium and strontium from geopolymers was evaluated in accordance with ANSI/ANS-16.1. The diffusivity of cesium and strontium in a fly ash-based geopolymer was lower than that in Portland cement by a factor of 10{sup 3} and 10{sup 4}, respectively, showing significantly improved immobilization performance. The leaching resistance of fly ash-based geopolymer was relatively constant regardless of the type of fly ash. The diffusivity of water-soluble cesium and strontium ions were highly correlated with the critical pore diameter of the binder. The critical pore diameter of the fly ash-based geopolymer was remarkably smaller than those of Portland cement and slag-blended geopolymer; consequently, its ability physically to retard the diffusion of nuclides (physical barrier effect) was superior.

  20. Interaction of the cesium cation with meso-octamethylcalix[4]pyrrole: Experimental and theoretical study

    Czech Academy of Sciences Publication Activity Database

    Polášek, Miroslav; Makrlík, E.; Kvíčala, J.; Křížová, Věra; Vaňura, P.

    2017-01-01

    Roč. 670, FEB 2017 (2017), s. 22-26 ISSN 0009-2614 Grant - others:GA MŠk(CZ) 20/2015; GA MŠk(CZ) LM2010005 Institutional support: RVO:61388955 Keywords : Aromatic compounds * Cesium * Electrospray ionization Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.815, year: 2016

  1. Strontium-90 and cesium-137 in total diet (from Oct. 1981 to Jul. 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in total diet (from Oct. 1981 to Jul. 1982) were determined. A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet'' from 26 sampling locations. The results are shown in a table. (Namekawa, K.)

  2. Strontium-90 and cesium-137 in total diet (from Nov. 1982 to Jun. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Strontium-90 and cesium-137 in total diet (from Nov. 1982 to Jun. 1983) were determined. A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet'' from 26 sampling locations. The results are shown in a table. (J.P.N.)

  3. Strontium-90 and cesium-137 in total diet (from Jun. 1982 to Dec. 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in total diet (from Jun. to Dec. 1982) were determined. A full one day ordinary diet including three meals, water, tea and other in-between snacks for five persons was collected as a sample of ''total diet'' from 22 sampling locations. The results are shown in a table. (Namekawa, K.)

  4. Immobilisation of radio cesium loaded ammonium molybdo phosphate in glass matrices

    International Nuclear Information System (INIS)

    Yalmali, Vrunda S.; Singh, I.J.; Sathi Sasidharan, N.; Deshingkar, D.S.

    2004-11-01

    Long half life and easy availability from high level wastes make 137 Cesium most economical radiation source. High level liquid waste processing for 137 Cesium removal has become easier due to development of Cesium specific granulated ammonium molybdophosphate (AMP) composite. In such applications, resulting spent composite AMP itself represents high active solid waste and immobilization of these materials in cement may not be acceptable. Studies on immobilization of 137 Cs loaded AMP were taken up in order to achieve twin goals of increasing safety and minimizing processing costs of the final matrix. Studies indicated that phosphate modified sodium borosilicate SPNM glasses prepared under usual oxidizing conditions are not suitable for immobilization of 137 Cs loaded on AMP .Phosphate glasses containing Na 2 O, P 2 O 5 , B 2 O 3 , Fe 2 O 3 , Al 2 O 3 and SiO 2 as major constituents are capable of incorporating 6 to 8 % AMP. The Normalized Leach rates of these glasses for sodium, cesium, boron and silica are 10 -4 to 10 -6 gm/cm 2 /day which are comparable to or better than those reported for NBS glasses incorporating HLW. Homogeneity of the final matrix was confirmed by x-ray diffraction analysis. Further studies on characterization of these glasses would establish their acceptability. (author)

  5. Cyclotron production of cesium radionuclides as analogues for francium-221 biodistribution

    International Nuclear Information System (INIS)

    Finn, R.; McDevitt, M.; Sheh, Y.; Lom, C.; Qiao, J.; Cai, S.; Burnazi, E.; Nacca, A.; Pillarsetty, N.; Jaggi, J.; Scheinberg, D.

    2005-01-01

    In our clinical investigations focussing on improved therapeutic treatment of specific tumors we have concentrated on a targeted therapy approach utilizing designed radiolabeled monoclonal antibodies as the cytotoxic reagent. The physical characteristics of the alpha particle emitting radionuclide bismuth-213 including the short half-life of 45.6 min, has shown promise for the treatment of specific cancers such as leukemias and lymphomas or micrometastatic carcinomas. In an effort to increase the cytocidal effect of the HuM195, a humanized monoclonal antibody carrier to the CD33 antigen expressed on leukemia cells, our focus is directed toward an 'internal' nano-generator composed of Ac-225 radionuclide, the parent of the bismuth-213. The actinium-225 radionuclide decays through several short-lived, alpha emitting daughters including francium-221, astatine-217 and bismuth-213. In order to study the biodistribution and the pharmacokinetics of the individual daughter nuclide, francium-221, the cyclotron production and separation of cesium radionuclides, specifically cesium-132, from a natural xenon gas target was undertaken. The choice of cesium as an analogue for francium was predicated upon both elements being in Group 1A alkali metals and cesium radionuclide possesses a sufficient half-life to allow biodistribution studies to be performed. The preliminary experimental results of this investigation are presented

  6. Physical barrier effect of geopolymeric waste form on diffusivity of cesium and strontium.

    Science.gov (United States)

    Jang, J G; Park, S M; Lee, H K

    2016-11-15

    The present study investigates the physical barrier effect of geopolymeric waste form on leaching behavior of cesium and strontium. Fly ash-based geopolymers and slag-blended geopolymers were used as solidification agents. The leaching behavior of cesium and strontium from geopolymers was evaluated in accordance with ANSI/ANS-16.1. The diffusivity of cesium and strontium in a fly ash-based geopolymer was lower than that in Portland cement by a factor of 10(3) and 10(4), respectively, showing significantly improved immobilization performance. The leaching resistance of fly ash-based geopolymer was relatively constant regardless of the type of fly ash. The diffusivity of water-soluble cesium and strontium ions were highly correlated with the critical pore diameter of the binder. The critical pore diameter of the fly ash-based geopolymer was remarkably smaller than those of Portland cement and slag-blended geopolymer; consequently, its ability physically to retard the diffusion of nuclides (physical barrier effect) was superior. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Evaluating water erosion prediction project model using Cesium-137-derived spatial soil redistribution data

    Science.gov (United States)

    The lack of spatial soil erosion data has been a major constraint on the refinement and application of physically based erosion models. Spatially distributed models can only be thoroughly validated with distributed erosion data. The fallout cesium-137 has been widely used to generate spatial soil re...

  8. Using Radioactive Fallout Cesium (137Cs) to Distinguish Sediment Sources in an Agricultural Watershed

    Science.gov (United States)

    Radioactive fallout Cesium (Cs-137) has been used for quantifying sources of accumulating sediment in water bodies and to determine the rates and pattern of soil erosion. The objectives of this research are to use Cs-137 as a tracer to determine patterns of soil erosion and deposition of eroding soi...

  9. HIGH TEMPERATURE SORPTION OF CESIUM AND STRONTIUM ON DISPERSED KAOLINITE POWDERS

    Science.gov (United States)

    Sorption of cesium and strontium on kaolinite powders was investigated as a means to minimize the emissions of these metals during certain high-temperature processes currently being developed to isolate and dispose of radiological and mixed wastes. In this work, nonradioactive aq...

  10. Surface Termination, Morphology and Bright Photoluminescence of Cesium Lead Halide Perovskite Nanocrystals

    NARCIS (Netherlands)

    ten Brinck, Stephanie; Infante, Ivan

    2016-01-01

    Colloidal cesium lead halide perovskite nanocrystals (CsPbX3 PNC, X=Cl, Br, I) exhibit important optoelectronic properties that make them amenable for a plethora of applications. The origin of these properties, even for as-synthesized and unpurified PNCs, is however largely unknown. Electronic

  11. Synthesis, characterization of cesium and cobalt substituted wells–Dawson heteropolyoxotungstates salts and their photocatalytic applications

    Directory of Open Access Journals (Sweden)

    Balaska A.

    2013-09-01

    Full Text Available Heteropoly compounds in the solid state are ionic crystals (sometimes amorphous consisting of large polyanions, cations, water of crystallization, and other molecules. Heteropolyacids (HPAs have several advantages as catalysts. On the one hand, they have a very strong Brønsted acidity, especially the cobalt and cesium salts; on the other hand they are exhibiting fast reversible multielectron redox transformations under mild conditions. The cobalt and cesium salts of wells–Dawson HPAs were synthesized and characterized using elemental analysis and spectroscopic techniques (31P-NMR, FT-IR. The wells–Dawson anions possess the ability to accept or release electrons through an external potential or upon exposure to UV radiation (photochemical reactions. The catalytic tests of these salts were investigated on phenol degradation where the UV photodegradation of acidified aqueous solutions (pH = 2 were studied in a batch photoreactor under ambient temperature and continuous circulation of phenol solution. The results reveal high catalytic activity for two HPAs, the best catalyst is the salt of cesium; where the presence of cesium improves significantly both the photcatalytic activity and the selectivity to oxalic acid.

  12. Vitrification of Cesium-Laden Organic Ion Exchange Resin in a Stirred Melter

    Energy Technology Data Exchange (ETDEWEB)

    Cicero-Herman, C.A [Westinghouse Savannah River Company, AIKEN, SC (United States); Sargent, T.N.; Overcamp, T.J.; Bickford, D.F.

    1997-07-09

    The goal of this research was a feasibility study for vitrifying the organic ion exchange resin in a stirred-tank melter. Tests were conducted to determine the fate of cesium including the feed, exit glass, and offgas streams and to assess any impact of feeding the resin on the melter or its performance.

  13. Assessment of commercially available ion exchange materials for cesium removal from highly alkaline wastes

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, K.P.; Kim, A.Y.; Kurath, D.E.

    1996-04-01

    Approximately 61 million gallons of nuclear waste generated in plutonium production, radionuclide removal campaigns, and research and development activities is stored on the Department of Energy`s Hanford Site, near Richland, Washington. Although the pretreatment process and disposal requirements are still being defined, most pretreatment scenarios include removal of cesium from the aqueous streams. In many cases, after cesium is removed, the dissolved salt cakes and supernates can be disposed of as LLW. Ion exchange has been a leading candidate for this separation. Ion exchange systems have the advantage of simplicity of equipment and operation and provide many theoretical stages in a small space. The organic ion exchange material Duolite{trademark} CS-100 has been selected as the baseline exchanger for conceptual design of the Initial Pretreatment Module (IPM). Use of CS-100 was chosen because it is considered a conservative, technologically feasible approach. During FY 96, final resin down-selection will occur for IPM Title 1 design. Alternate ion exchange materials for cesium exchange will be considered at that time. The purpose of this report is to conduct a search for commercially available ion exchange materials which could potentially replace CS-100. This report will provide where possible a comparison of these resin in their ability to remove low concentrations of cesium from highly alkaline solutions. Materials which show promise can be studied further, while less encouraging resins can be eliminated from consideration.

  14. Potassium, rubidium and cesium oxodiselenatovanadates (5), MVO(SeO4)2

    International Nuclear Information System (INIS)

    Krasil'nikov, V.N.; Glazyrin, M.P.; Ivakin, A.A.

    1987-01-01

    Conditions of formation and properties of potassium, rubidium and cesium oxodiselenatovanadates (5), MVO(SeO 4 ) 2 were studied. Their chemical and structural similarity to the known oxosulfatovanadates (5) of alkali metals and thallium, MVO(SO 4 ) 2 was established

  15. Reaction kinetics of iodine and cesium in steam/hydrogen mixtures

    International Nuclear Information System (INIS)

    Cronenberg, A.W.; Osetek, D.J.

    1988-01-01

    The chemical reaction kinetics of fission product iodine and cesium released from fuel to a steam/hydrogen atmosphere are investigated at conditions associated with severe core damage accidents. The results are used to assess the time to establish equilibrium and the ultimate chemical form of iodine and cesium as a function of gas mixture concentration and temperature conditions. Illustrative calculations are presented for interpretation of the chemical form of iodine and cesium during the Three Mile Island Unit 2 accident, as well as for recent severe fuel damage experiments. At low fusion product concentrations (fission product/steam mole ratio < 10/sup -8/), the time to establish equilibrium may be on the order of tens of seconds, with the principal species being CsOH and H1. However, at fission product/steam mole ratios exceeding 10/sup -5/, the principal species are CsOH and CsI, with an equilibrium time of -- 10/sup -4/s. Concentration conditions thus influence the ultimate chemical form of fission products in a steam/hydrogen gas mixture and the time to establish thermochemical equilibrium. Fission product concentration conditions should therefore be considered in the specification of the chemical form of iodine and cesium gas-phase transport for nuclear plant accident consequence analysis

  16. Adsorption of cesium on Czech smectite-rich clays - A comparative study

    Czech Academy of Sciences Publication Activity Database

    Vejsada, J.; Hradil, D.; Řanda, Zdeněk; Jelínek, E.; Stulík, K.

    2005-01-01

    Roč. 30, č. 1 (2005), s. 53-66 ISSN 0169-1317 R&D Projects: GA ČR GA104/02/1464; GA MŠk LN00A028 Institutional research plan: CEZ:AV0Z10480505 Keywords : cesium * adsorption * Freundlich isotherm Subject RIV: EF - Botanics Impact factor: 1.324, year: 2005

  17. Adsorption of cesium on Czech smectite-rich clays - A comparative study

    Czech Academy of Sciences Publication Activity Database

    Vejsada, J.; Hradil, David; Řanda, Zdeněk; Jelínek, E.; Štulík, K.

    2005-01-01

    Roč. 30, č. 1 (2005), s. 53-66 ISSN 0169-1317 R&D Projects: GA ČR GA104/02/1464; GA AV ČR IAA3032401 Institutional research plan: CEZ:AV0Z40320502 Keywords : cesium * adsorption * batch method Subject RIV: CA - Inorganic Chemistry Impact factor: 1.324, year: 2005

  18. Extraction and DFT study on the complexation of the cesium cation with dibenzo-21-crown-7

    Czech Academy of Sciences Publication Activity Database

    Makrlík, E.; Toman, Petr; Vaňura, P.

    2011-01-01

    Roč. 289, č. 3 (2011), s. 667-670 ISSN 0236-5731 R&D Projects: GA ČR(CZ) GAP205/10/2280 Institutional research plan: CEZ:AV0Z40500505 Keywords : cesium dibenzo-21-crown-7 * nitrobenzene * stability constant Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.520, year: 2011

  19. Experimental and theoretical study on the complexation of the cesium cation with dibenzo-30-crown-10

    Czech Academy of Sciences Publication Activity Database

    Makrlík, E.; Toman, Petr; Vaňura, P.

    2012-01-01

    Roč. 292, č. 3 (2012), s. 1137-1140 ISSN 0236-5731 R&D Projects: GA ČR(CZ) GAP205/10/2280 Institutional research plan: CEZ:AV0Z40500505 Keywords : cesium * picrate * extraction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.467, year: 2012

  20. Removal of cesium and strontium from low active waste solutions by zeolites

    International Nuclear Information System (INIS)

    Jain, Savita; Ramaswamy, M.; Theyyunni, T.K.

    1994-01-01

    Ion exchange, crystallographic and thermal characteristics of sodium, cesium and strontium forms of locally available synthetic zeolites have been investigated. X-ray and differential thermal analyses have confirmed that the synthetic materials AR1 and 4A belonged to the mordenite and A type families of zeolites respectively. Equilibrium uptake of cesium and strontium ions by sodium forms of zeolite was studied as a function of time, pH and sodium concentration. It was found that the rate of sorption by AR1 was higher than that by 4A. In regard to pH, distribution of nuclides on zeolites was found to pass through maxima at a pH value of around 9. Sodium ion interfered with the sorption of cesium and strontium by zeolites. However, at sodium concentration ≤ 0.01 M, distribution coefficient values for these nuclides were sufficiently high to merit consideration of these zeolites for low level waste treatment. Lab-scale column runs using 5 ml beds of materials showed that the zeolites AR1 and 4A were very effective in removing cesium and strontium nuclides respectively from large volumes (a decontamination factor of 50 for a throughput of 6000 bed volumes) of actual low level waste solutions. Thus, the zeolite system has a potential future for large scale application in the treatment of low level wastes. (author). 6 refs., 5 figs., 6 tabs

  1. Assessment of commercially available ion exchange materials for cesium removal from highly alkaline wastes

    International Nuclear Information System (INIS)

    Brooks, K.P.; Kim, A.Y.; Kurath, D.E.

    1996-04-01

    Approximately 61 million gallons of nuclear waste generated in plutonium production, radionuclide removal campaigns, and research and development activities is stored on the Department of Energy's Hanford Site, near Richland, Washington. Although the pretreatment process and disposal requirements are still being defined, most pretreatment scenarios include removal of cesium from the aqueous streams. In many cases, after cesium is removed, the dissolved salt cakes and supernates can be disposed of as LLW. Ion exchange has been a leading candidate for this separation. Ion exchange systems have the advantage of simplicity of equipment and operation and provide many theoretical stages in a small space. The organic ion exchange material Duolite trademark CS-100 has been selected as the baseline exchanger for conceptual design of the Initial Pretreatment Module (IPM). Use of CS-100 was chosen because it is considered a conservative, technologically feasible approach. During FY 96, final resin down-selection will occur for IPM Title 1 design. Alternate ion exchange materials for cesium exchange will be considered at that time. The purpose of this report is to conduct a search for commercially available ion exchange materials which could potentially replace CS-100. This report will provide where possible a comparison of these resin in their ability to remove low concentrations of cesium from highly alkaline solutions. Materials which show promise can be studied further, while less encouraging resins can be eliminated from consideration

  2. Evaluation of selected ion exchangers for the removal of cesium from MVST W-25 supernate

    International Nuclear Information System (INIS)

    Collins, J.L.; Egan, B.Z.; Anderson, K.K.; Chase, C.W.; Mrochek, J.E.; Bell, J.T.; Jernigan, G.E.

    1995-04-01

    The goal of this batch-test equilibration study was to evaluate the effectiveness of certain ion exchangers for removing cesium from supernate taken from tank W-25 of the Melton Valley Storage Tank (MVST) Facility located at the Oak Ridge National Laboratory (ORNL). These exchangers were selective for removing cesium from alkaline supernatant solutions with high salt concentrations. Since the supernates of evaporator concentrates stored in tanks at the MVST facility have compositions similar to some of those stored in tanks at Hanford, the data generated in this study should prove useful in the overall evaluation of the ion exchangers for applications to Hanford and other US Department of Energy (USDOE) sites. A goal of the waste processing effort at Hanford is to remove enough cesium to ensure that the resulting LLW will meet the Nuclear Regulatory Commission (NRC) 10 CFR 61 class A limit for 137 Cs (1 Ci/m 3 or 1 μCi/mL). The separated cesium may be concentrated and vitrified for disposal in the high-level waste repository. The decontaminated effluent would be solidified for near-surface disposal

  3. Decontamination of spent ion-exchangers contaminated with cesium radionuclides using resorcinol-formaldehyde resins

    Energy Technology Data Exchange (ETDEWEB)

    Palamarchuk, Marina, E-mail: marina_p@ich.dvo.ru; Egorin, Andrey; Tokar, Eduard; Tutov, Mikhail; Marinin, Dmitry; Avramenko, Valentin

    2017-01-05

    Highlights: • Cesium radionuclides not removable by regeneration are bound to silicate deposits. • Application of RFR substantially increases cesium desorption from an ion-exchanger. • The radwaste volume was reduced at least 2-fold for zeolites and 10-fold for SIER. • The distribution coefficient values for RFR were high (K{sub d} > 10{sup 4}) after 6 regenerations. • The volume of secondary waste formed after regeneration of RFR was reduced 600-fold. - Abstract: The origin of the emergence of radioactive contamination not removable in the process of acid-base regeneration of ion-exchange resins used in treatment of technological media and liquid radioactive waste streams has been determined. It has been shown that a majority of cesium radionuclides not removable by regeneration are bound to inorganic deposits on the surface and inside the ion-exchange resin beads. The nature of the above inorganic inclusions has been investigated by means of the methods of electron microscopy, IR spectrometry and X-ray diffraction. The method of decontamination of spent ion-exchange resins and zeolites contaminated with cesium radionuclides employing selective resorcinol-formaldehyde resins has been suggested. Good prospects of such an approach in deep decontamination of spent ion exchangers have been demonstrated.

  4. Decontamination of spent ion-exchangers contaminated with cesium radionuclides using resorcinol-formaldehyde resins

    International Nuclear Information System (INIS)

    Palamarchuk, Marina; Egorin, Andrey; Tokar, Eduard; Tutov, Mikhail; Marinin, Dmitry; Avramenko, Valentin

    2017-01-01

    Highlights: • Cesium radionuclides not removable by regeneration are bound to silicate deposits. • Application of RFR substantially increases cesium desorption from an ion-exchanger. • The radwaste volume was reduced at least 2-fold for zeolites and 10-fold for SIER. • The distribution coefficient values for RFR were high (K d > 10 4 ) after 6 regenerations. • The volume of secondary waste formed after regeneration of RFR was reduced 600-fold. - Abstract: The origin of the emergence of radioactive contamination not removable in the process of acid-base regeneration of ion-exchange resins used in treatment of technological media and liquid radioactive waste streams has been determined. It has been shown that a majority of cesium radionuclides not removable by regeneration are bound to inorganic deposits on the surface and inside the ion-exchange resin beads. The nature of the above inorganic inclusions has been investigated by means of the methods of electron microscopy, IR spectrometry and X-ray diffraction. The method of decontamination of spent ion-exchange resins and zeolites contaminated with cesium radionuclides employing selective resorcinol-formaldehyde resins has been suggested. Good prospects of such an approach in deep decontamination of spent ion exchangers have been demonstrated.

  5. Proceedings of the 1. International Symposium on radioactive accident with cesium 137 in Goiania

    International Nuclear Information System (INIS)

    1988-01-01

    The 1. International Symposium about Radioactive Accident with cesium 137 in Goiania - Brazil had the purpose to know all the aspects of the accident such as the medical emergencial surveillance, odontological care with the victims, anatomo-pathologic examinations in the lethal cases radio lesions treatment. (L.M.J.)

  6. Strontium-90 and cesium-137 in sea fish (from Oct. 1981 to Jun. 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in sea fishes (from Oct. 1981 to Jun. 1982) were determined. Fish was collected from eight sampling locations. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. The results are shown in a table. (Namekawa, K.)

  7. Strontium-90 and cesium-137 in sea fish (from Nov. 1982 to Jun. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Strontium-90 and cesium-137 in sea fish (from Nov. 1982 to Jun. 1983) were determined. Fishes were collected from eight sampling locations. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. The results are shown in a table. (J.P.N.)

  8. Strontium-90 and cesium-137 in sea fish (from Jun. 1982 to Dec. 1982)

    International Nuclear Information System (INIS)

    1982-01-01

    Strontium-90 and cesium-137 in sea fish (from Jun. to Dec. 1982) were determined. Fish was collected from 22 sampling locations. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. The results are sown in a table. (Namekawa, K.)

  9. Cyclotron production of cesium radionuclides as analogues for francium-221 biodistribution

    Energy Technology Data Exchange (ETDEWEB)

    Finn, R. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States) and Cyclotron Core Facility, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States)]. E-mail: finnr@mskcc.org; McDevitt, M. [Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Department of Medicine, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Sheh, Y. [Cyclotron Core Facility, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Lom, C. [Cyclotron Core Facility, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Qiao, J. [Cyclotron Core Facility, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Cai, S. [Cyclotron Core Facility, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Burnazi, E. [Cyclotron Core Facility, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Nacca, A. [Cyclotron Core Facility, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Pillarsetty, N. [Cyclotron Core Facility, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Jaggi, J. [Department of Medicine, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States); Scheinberg, D. [Department of Medicine, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021 (United States)

    2005-12-15

    In our clinical investigations focussing on improved therapeutic treatment of specific tumors we have concentrated on a targeted therapy approach utilizing designed radiolabeled monoclonal antibodies as the cytotoxic reagent. The physical characteristics of the alpha particle emitting radionuclide bismuth-213 including the short half-life of 45.6 min, has shown promise for the treatment of specific cancers such as leukemias and lymphomas or micrometastatic carcinomas. In an effort to increase the cytocidal effect of the HuM195, a humanized monoclonal antibody carrier to the CD33 antigen expressed on leukemia cells, our focus is directed toward an 'internal' nano-generator composed of Ac-225 radionuclide, the parent of the bismuth-213. The actinium-225 radionuclide decays through several short-lived, alpha emitting daughters including francium-221, astatine-217 and bismuth-213. In order to study the biodistribution and the pharmacokinetics of the individual daughter nuclide, francium-221, the cyclotron production and separation of cesium radionuclides, specifically cesium-132, from a natural xenon gas target was undertaken. The choice of cesium as an analogue for francium was predicated upon both elements being in Group 1A alkali metals and cesium radionuclide possesses a sufficient half-life to allow biodistribution studies to be performed. The preliminary experimental results of this investigation are presented.

  10. Novel matching lens and spherical ionizer for a cesium sputter ion ...

    Indian Academy of Sciences (India)

    Department of Nuclear Physics, Research School of Physical Sciences and Engineering,. Australian National University ... ionizer power and Cs reservoir temperature are shown. The three curves correspond to .... Cesium sputter ion source. One could gain the benefits of the higher C energy by just increasing the extractor.

  11. Complexation of the cesium cation with lithium ionophore VIII: extraction and DFT study

    Czech Academy of Sciences Publication Activity Database

    Makrlík, E.; Novák, Vít; Vaňura, P.; Bouř, Petr

    2013-01-01

    Roč. 298, č. 3 (2013), s. 2065-2068 ISSN 0236-5731 Institutional support: RVO:61388963 Keywords : cesium cation * lithium ionophore VIII * complexation * extraction and stability constants * water-nitrobenzene system * DFT calculations * structures Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 1.415, year: 2013

  12. Complexation of the cesium cation with nonactin: extraction and DFT study

    Czech Academy of Sciences Publication Activity Database

    Makrlík, E.; Toman, Petr; Vaňura, P.

    2013-01-01

    Roč. 295, č. 1 (2013), s. 615-619 ISSN 0236-5731 R&D Projects: GA ČR(CZ) GAP205/10/2280 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : cesium * nonactin * complexation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.415, year: 2013

  13. The prognostic utility of the SYNTAX score on 1-year outcomes after revascularization with zotarolimus- and everolimus-eluting stents: a substudy of the RESOLUTE All Comers Trial

    DEFF Research Database (Denmark)

    Garg, Scot; Serruys, Patrick W; Silber, Sigmund

    2011-01-01

    This study assessed the ability of the SYNTAX score (SXscore) to stratify risk in patients treated with percutaneous coronary intervention (PCI) using zotarolimus-eluting or everolimus-eluting stents.......This study assessed the ability of the SYNTAX score (SXscore) to stratify risk in patients treated with percutaneous coronary intervention (PCI) using zotarolimus-eluting or everolimus-eluting stents....

  14. Impact of alkaline alterations to a Brazilian soil on cesium retention under low temperature conditions.

    Science.gov (United States)

    Calábria, Jaqueline Alves de Almeida; Cota, Stela Dalva Santos; de Morais, Gustavo Ferrari; Ladeira, Ana Cláudia Queiroz

    2017-11-01

    To be used as backfilling materials in radioactive waste disposal facilities, a natural material must have a suitable permeability, mechanical properties and a high sorption capacity for radionuclides. Also important when considering a material as a backfill is the effect of its interaction with the alkaline solution generated from concrete degradation. This solution promotes mineralogical alterations that result in significant changes in the material key properties influencing its performance as a safety component of the repository. This paper presents results of an investigation on the effect of alkaline interaction under a low temperature on cesium retention properties of a local soil being considered suitable as a backfill for the Brazilian near surface disposal facility. A sample of the Brazilian soil was mixed with an alkaline solution, simulating the pore water leached in the first stage of cement degradation, during 1, 7, 14 and 28 days. The experiments were conducted under low temperature (25 °C) aiming to evaluate similar conditions found on a low and intermediate level radioactive waste disposal installation. A non-classical isotherm sorption model was fitted to sorption data obtained from batch experiments, for unaltered and altered samples, providing parameters that allowed us to assess the effect of the interaction on material quality as Cs sorbent. The sorption parameters obtained from the data-fitted isotherm were used then to estimate the corresponding retardation factor (R). Alkaline interaction significantly modified the soil sorption properties for Cs. The parameter Q, related to the maximum sorption capacity, as well as the affinity parameter (K) and the retardation coefficients became significantly smaller (about 1000 times for the R coefficient) after pretreatment with the simulated alkaline solutions. Moreover, the increase in n-values, which is related with the energy distribution width and heterogeneity of surface site energies

  15. Radioactive cesium removal from seawater using adsorptive fibers prepared by radiation-induced graft polymerization

    International Nuclear Information System (INIS)

    Goto, Shota; Kawai-Noma, Shigeko; Umeno, Daisuke; Saito, Kyoichi; Fujiwara, Kunio; Sugo, Takanobu; Kikuchi, Takahiro; Morimoto, Yasutomi

    2015-01-01

    The meltdown of three reactors of the TEPCO Fukushima Daiichi nuclear power station (NPS) caused by the Great East Japan Earthquake on March 11th 2011 resulted in the emission of radionuclides such as cesium-137 and strontium-90 to the environment. For example, radioactive cesium exceeding the legal discharge limit (90 Bq/L, 2×10 -13 M) was detected in the seawater of the seawater-intake area of the NPS at the end of September 2014. Adsorbents with a high selectivity for cesium ions over other alkali metal ions such as sodium and potassium ions are required for cesium removal from seawater because sodium and potassium ions dissolve respectively at much higher concentrations of 5×10 -1 and 1×10 -2 M than cesium ions (2×10 -9 M). In addition, the simple operations of the immersion in seawater and the recovery of the adsorbents from seawater are desirable at decontamination sites. We prepared a cobalt-ferrocyanide-impregnated fiber capable of specifically capturing cesium ions in seawater by radiation-induced graft polymerization and chemical modifications. First, a commercially available 6-nylon fiber was irradiated with γ-rays. Second, an epoxy-group-containing vinyl monomer, glycidyl methacrylate, was graft-polymerized onto the γ-ray-irradiated nylon fiber. Third, the epoxy ring of the grafted polymer chain was reacted with triethylenediamine to obtain an anion-exchange fiber. Fourth, ferrocyanide ions, [Fe(CN) 6 ] 4 - , were bound to the anion-exchange group of the polymer chains. Finally, the ferrocyanide-ion-bound-fiber was placed in contact with cobalt chloride to precipitate insoluble cobalt ferrocyanide onto the polymer chains. Insoluble cobalt ferrocyanide was immobilized at the periphery of the fiber. However, the impregnation structure remains unclear. Here, we clarified the structure of insoluble cobalt ferrocyanide impregnated onto the polymer chain grafted onto the fiber to ensure the chemical and physical stability of the adsorptive fiber in

  16. Randomized comparison of a sirolimus-eluting Orsiro stent with a biolimus-eluting Nobori stent in patients treated with percutaneous coronary intervention

    DEFF Research Database (Denmark)

    Jensen, Lisette Okkels; Thayssen, Per; Maeng, Michael

    2015-01-01

    -coating releasing sirolimus from a biodegradable polymer (O-SES, Orsiro; Biotronik, Bülach, Switzerland) with the stainless steel biodegradable polymer biolimus-eluting Nobori stents (N-BES, Nobori; Terumo, Tokyo, Japan) in an all-comer patient population. DESIGN: The multicenter SORT OUT VII trial (NCT01879358...

  17. Everolimus eluting stent vs first generation drug-eluting stent in primary angioplasty: A pooled patient-level meta-analysis of randomized trials

    NARCIS (Netherlands)

    Luca, G. De; Smits, Peter; Hofma, S.H.; Lorenzo, E. Di; Vlachojannis, G.J.; Hof, A.W. van 't; Boven, A.J. van; Kedhi, E.; Stone, G.W.; Suryapranata, H.

    2017-01-01

    BACKGROUND: Several concerns have emerged about the higher risk of very late stent thrombosis (ST) with first generation drug-eluting stent (DES) especially among STEMI patients. Newer generation DES has demonstrated to reduce ST at mid-term follow-up. Therefore, the aim of the present study is to

  18. Intravascular ultrasound assessment of expansion of the sirolimus-eluting (Cypher Select) and paclitaxel-eluting (Taxus Express-2) stent in patients with diabetes mellitus

    DEFF Research Database (Denmark)

    Jensen, L.O.; Maeng, M.; Mintz, G.S.

    2008-01-01

    Patients with diabetes have a higher risk for in-stent restenosis after coronary stent implantation. Drug-eluting stents (DES) are highly effective in reducing in-stent restenosis. Once neointimal hyperplasia is suppressed with DES, the impact of stent underexpansion becomes magnified. The aim of...

  19. Nonequilibrium sorptive behavior of cobalt, cesium, and strontium on Bandelier Tuff: experiments and analysis

    International Nuclear Information System (INIS)

    Fuentes, H.R.; Polzer, W.L.; Essington, E.H.; Roensch, F.R.

    1985-01-01

    Information is presented on the nonequilibrium sorption of cobalt, cesium and strontium on Bandelier Tuff. Both adsorption and desorption were studied in the batch at 25 0 C with constant mixing. The reaction solutions consisted of 20 mg/L of stable cobalt, cesium or strontium with their radioactive tracers 60 Co, 137 Cs or 85 Sr, in 0.01N CaCl 2 solution. Adsorption equilibrium occurs rapidly for strontium, somewhat more slowly for cesium, and very slowly for cobalt. The degree of adsorption is approximately 19% for stronium 49% for cesium, and 84% for cobalt. Desorption (leaching) initially occurs in a relatively rapid step followed by a much slower rate. The relative adsorption and desorption rates can be explained or predicted by theoretical considerations of the Modified Freundlich isotherm and Hill Plot analyses of equilibrium sorption data. The Modified Freundlich isotherm analysis predicts that soil will exhibit ranges in relative energies of sorption and in reaction rates; the Hill Plot analysis predicts interactions among sorption sites. Nonequilibrium sorption data indicate that the ranges in relative energies and reaction rates are different for specific solutes and are dependent on interactions among sorption sites; the greater the interaction among sorption sites, the greater the range of reaction rates. The results of this study suggest that equilibrium models may be adequate to describe the movement of strontium in Bandelier Tuff under dynamic flow conditions. However, nonequilibrium models, in all probability, will be needed to describe the movement of cesium and cobalt under those same conditions. 9 references, 6 figures, 4 tables

  20. Web-Based Geospatial Visualization of GPM Data with CesiumJS

    Science.gov (United States)

    Lammers, Matt

    2018-01-01

    Advancements in the capabilities of JavaScript frameworks and web browsing technology have made online visualization of large geospatial datasets such as those coming from precipitation satellites viable. These data benefit from being visualized on and above a three-dimensional surface. The open-source JavaScript framework CesiumJS (http://cesiumjs.org), developed by Analytical Graphics, Inc., leverages the WebGL protocol to do just that. This presentation will describe how CesiumJS has been used in three-dimensional visualization products developed as part of the NASA Precipitation Processing System (PPS) STORM data-order website. Existing methods of interacting with Global Precipitation Measurement (GPM) Mission data primarily focus on two-dimensional static images, whether displaying vertical slices or horizontal surface/height-level maps. These methods limit interactivity with the robust three-dimensional data coming from the GPM core satellite. Integrating the data with CesiumJS in a web-based user interface has allowed us to create the following products. We have linked with the data-order interface an on-the-fly visualization tool for any GPM/partner satellite orbit. A version of this tool also focuses on high-impact weather events. It enables viewing of combined radar and microwave-derived precipitation data on mobile devices and in a way that can be embedded into other websites. We also have used CesiumJS to visualize a method of integrating gridded precipitation data with modeled wind speeds that animates over time. Emphasis in the presentation will be placed on how a variety of technical methods were used to create these tools, and how the flexibility of the CesiumJS framework facilitates creative approaches to interact with the data.

  1. Strontium-90 and cesium-137 in soil (from Jun. 1983 to Sept. 1983)

    International Nuclear Information System (INIS)

    1983-01-01

    Results are presented for the determination of strontium-90 and cesium-137 in soils in Japan. Twenty-seven sampling points were selected all over Japan from Hokkaido to Okinawa by the criteria that the points were spacious and flat without past disturbance and those located in a forest, in a stony area or inside of river banks should be avoided. Soils were taken from two layers of depth, 0 to 5 cm and 5 to 20 cm. After drying, soils were passed through a 2 mm sieve and were employed for radiochemical leaching, separation, and purification of strontium-90 or cesium-137. Radioactivity of strontium-90 or cesium-137 was determined with a low background beta counter normally for 60 minutes. Determined values are presented as pCi/kg and mCi/km 2 for two different depth layers. As for strontium-90 contents, they were ranged from 13.0 +- 3.3 pCi/kg-dry (Aomori, 5 to 20 cm) to 1300 +- 20 pCi/kg-dry (Oota, Shimane Pref., 0 to 5 cm), or from 1.1 +- 0.14 mCi/km 2 (Tsuyama, Okayama Pref., 0 to 5 cm) to 50.0 +- 1.7 mCi/km 2 (Sapporo, 5 to 20 cm). As for cesium-137 contents, they were ranged from 0.5 +- 2.2 pCi/kg-dry (Saga, 5 to 20 cm) to 4700 +- 40 pCi/kg-dry (Oota, Shimane Pref., 0 to 5 cm) or from 0.1 +- 0.42 mCi/km 2 (Saga, 5 to 20 cm) to 120.0 +- 2.0 mCi/km 2 (Oota, Shimane Pref., 5 to 20 cm), and the variance for cesium-137 values were larger than those for strontium-90. Seasonal or local tendency for the contents of the two nuclides were not clarified. (Takagi, S.)

  2. Preparation and use of polymeric materials containing hydrophobic anions and plasticizers for separation of cesium and strontium

    Science.gov (United States)

    Abney, K.D.; Kinkead, S.A.; Mason, C.F.V.; Rais, J.

    1997-09-09

    Preparation and use is described for polymeric materials containing hydrophobic anions and plasticizers for extraction of cesium and strontium. The use of polymeric materials containing plasticizers which are solvents for hydrophobic anions such as derivatives of cobalt dicarbollide or tetraphenylborate which are capable of extracting cesium and strontium ions from aqueous solutions in contact with the polymeric materials, is described. The polymeric material may also include a synergistic agent for a given ion like polyethylene glycol or a crown ether, for removal of radioactive isotopes of cesium and strontium from solutions of diverse composition and, in particular, for solutions containing large excess of sodium nitrate.

  3. The Influence of Irradiation Time and Layer Thickness on Elution of Triethylene Glycol Dimethacrylate from SDR® Bulk-Fill Composite

    Directory of Open Access Journals (Sweden)

    Ryta Łagocka

    2016-01-01

    Full Text Available Objective. This study aimed to evaluate triethylene glycol dimethacrylate (TEGDMA elution from SDR bulk-fill composite. Methods. Three groups of samples were prepared, including samples polymerized in a 4 mm layer for 20 s, in a 4 mm layer for 40 s, and in a 2 mm layer for 20 s. Elution of TEGDMA into 100% ethanol, a 75% ethanol/water solution, and distilled water was studied. The TEGDMA concentration was measured using HPLC. Results. The TEGDMA concentration decreased in the following order: 100% ethanol > 75% ethanol > distilled water. Doubling the energy delivered to the 4 mm thick sample caused decrease (p<0.05 in TEGDMA elution to distilled water. In ethanol solutions, the energy increase had no influence on TEGDMA elution. Decreasing the sample thickness resulted in decrease (p<0.05 in TEGDMA elution for all the solutions. Conclusions. The concentration of eluted TEGDMA and the elution time were both strongly affected by the hydrophobicity of the solvent. Doubling the energy delivered to the 4 mm thick sample did not decrease the elution of TEGDMA but did decrease the amount of the monomer available to less aggressive solvents. Elution of TEGDMA was also correlated with the exposed sample surface area. Clinical Relevance. Decreasing the SDR layer thickness decreases TEGDMA elution.

  4. 137Cesium and soil carbon in a small agricultural watershed

    International Nuclear Information System (INIS)

    Ritchie, J.C.; McCarty, G.W.

    2003-01-01

    Scientific, political, and social interests have developed recently in the concept of using agricultural soils to sequester carbon. Studies supporting this concept indicate that soil erosion and subsequent redeposition of eroded soils in the same field may establish an ecosystem disequilibrium that promotes the buildup of carbon on agricultural landscapes. The problem is to determine the patterns of soil erosion and redeposition on the landscape and to relate these to soil carbon patterns. Radioactive 137 cesium ( 137 Cs) can be used to estimate soil erosion patterns and, more importantly, redeposition patterns at the field level. The purpose of this study was to determine the relationship between 137 Cs, soil erosion, and soil carbon patterns on a small agricultural watershed. Profiles of soils from an upland area and soils in an adjacent riparian system were collected in 5 cm increments and the concentrations of 137 Cs and carbon were determined. 137 Cs and carbon were uniformly mixed in the upper 15-20 cm of upland soils. 137 Cs (Bq g -1 ) and carbon (%) in the upland soils were significantly correlated (r 2 =0.66). Carbon content of the 0-20 cm layer was higher (1.4±0.3%) in areas of soil deposition than carbon content (1.1±0.3%) in areas of soil erosion as determined by the 137 Cs technique. These data suggest that measurements of 137 Cs in the soils can be useful for understanding carbon distribution patterns in surface soil. Carbon content of the upland soils ranged from 0.5 to 1.9% with an average of 1.2±0.4% in the 0-20 cm layer while carbon below this upper tilled layer (20-30 cm) ranged from 0.2 to 1.5% with an average of 0.5±0.3%. Total carbon was 2.66 and 3.20 kg m -2 in the upper 20 cm and upper 30 cm of the upland soils, respectively. Carbon content of the 0-20 cm layer in the riparian system ranged from 1.1 to 67.0% with an average 11.7±17.1%. Carbon content below 20 cm ranged from 1.8 to 79.3% with an average of 18.3±17.5%. Soil carbon in the

  5. Paclitaxel Drug-eluting Tracheal Stent Could Reduce Granulation Tissue Formation in a Canine Model.

    Science.gov (United States)

    Wang, Ting; Zhang, Jie; Wang, Juan; Pei, Ying-Hua; Qiu, Xiao-Jian; Wang, Yu-Ling

    2016-11-20

    Currently available silicone and metallic stents for tracheal stenosis are associated with many problems. Granulation proliferation is one of the main complications. The present study aimed to evaluate the efficacy of paclitaxel drug-eluting tracheal stent in reducing granulation tissue formation in a canine model, as well as the pharmacokinetic features and safety profiles of the coated drug. Eight beagles were randomly divided into a control group (bare-metal stent group, n = 4) and an experimental group (paclitaxel-eluting stent group, n = 4). The observation period was 5 months. One beagle in both groups was sacrificed at the end of the 1st and 3rd months, respectively. The last two beagles in both groups were sacrificed at the end of 5th month. The proliferation of granulation tissue and changes in tracheal mucosa were compared between the two groups. Blood routine and liver and kidney function were monitored to evaluate the safety of the paclitaxel-eluting stent. The elution method and high-performance liquid chromatography were used to characterize the rate of in vivo release of paclitaxel from the stent. Compared with the control group, the proliferation of granulation tissue in the experimental group was significantly reduced. The drug release of paclitaxel-eluting stent was the fastest in the 1st month after implantation (up to 70.9%). Then, the release slowed down gradually. By the 5th month, the release reached up to 98.5%. During the observation period, a high concentration of the drug in the trachea (in the stented and adjacent unstented areas) and lung tissue was not noted, and the blood test showed no side effect. The paclitaxel-eluting stent could safely reduce the granulation tissue formation after stent implantation in vivo, suggesting that the paclitaxel-eluting tracheal stent might be considered for potential use in humans in the future.

  6. Reduction of Solvent Effect in Reverse Phase Gradient Elution LC-ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Patrick Allen [Iowa State Univ., Ames, IA (United States)

    2005-12-17

    %-35% (simulated) and 8%-32% (actual). Quadrupole (low resolution) and sector field (high resolution) ICP-MS instrumentation were utilized in these studies. Once an AIS pair is determined, quantification studies can be performed. First, an analysis is performed by adding both elements of the AIS pair post-column while performing the gradient elution without sample injection. A comparison of the ratio of the measured intensities to the atomic ratio of the two standards is used to determine a correction factor that can be used to account for the matrix effects caused by the mobile phase. Then, organic and/or biological molecules containing one of the two elements in the AIS pair are injected into the LC column. A gradient method is used to vary the methanol-water mixture in the mobile phase and to separate out the compounds in a given sample. A standard solution of the second ion in the AIS pair is added continuously post-column. By comparing the ratio of the measured intensities to the atomic ratio of the eluting compound and internal standard, the concentration of the injected compound can be determined.

  7. Cesium platinide hydride 4Cs{sub 2}Pt.CsH: an intermetallic double salt featuring metal anions

    Energy Technology Data Exchange (ETDEWEB)

    Smetana, Volodymyr [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Mudring, Anja-Verena [Ames Laboratory, US Department of Energy, and Critical Materials Institute, Ames, Iowa, 50011-3020 (United States); Department of Materials Sciences and Engineering, Iowa State University, Ames, Iowa, 50011-3111 (United States)

    2016-11-14

    With Cs{sub 9}Pt{sub 4}H a new representative of ionic compounds featuring metal anions can be added to this rare-membered family. Cs{sub 9}Pt{sub 4}H exhibits a complex crystal structure containing Cs{sup +} cations, Pt{sup 2-} and H{sup -} anions. Being a red, transparent compound its band gap is in the visible range of the electromagnetic spectrum and the ionic type of bonding is confirmed by quantum chemical calculations. This cesium platinide hydride can formally be considered as a double salt of the ''alloy'' cesium-platinum, or better cesium platinide, Cs{sub 2}Pt, and the salt cesium hydride CsH according to Cs{sub 9}Pt{sub 4}H≡4 Cs{sub 2}Pt.CsH. (copyright 2016 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Cesium platinide hydride 4Cs2Pt.CsH: an intermetallic double salt featuring metal anions

    International Nuclear Information System (INIS)

    Smetana, Volodymyr; Mudring, Anja-Verena

    2016-01-01

    With Cs 9 Pt 4 H a new representative of ionic compounds featuring metal anions can be added to this rare-membered family. Cs 9 Pt 4 H exhibits a complex crystal structure containing Cs + cations, Pt 2- and H - anions. Being a red, transparent compound its band gap is in the visible range of the electromagnetic spectrum and the ionic type of bonding is confirmed by quantum chemical calculations. This cesium platinide hydride can formally be considered as a double salt of the ''alloy'' cesium-platinum, or better cesium platinide, Cs 2 Pt, and the salt cesium hydride CsH according to Cs 9 Pt 4 H≡4 Cs 2 Pt.CsH. (copyright 2016 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Removal of cesium using coconut fiber in raw and modified forms for the treatment of radioactive liquid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Nella N.M. de; Nobre, Vanessa B.; Potiens Junior, Ademar J.; Sakata, Solange K., E-mail: sksakata@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Di Vitta, Patricia B. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Quimica

    2013-07-01

    Sorption is one of the most studied methods to reduce the volume of radioactive waste streams. Cesium-137 is a radioisotope formed by the fission of uranium and it can cause health problems due to its easy assimilation by cells. The aim of this study is to evaluate the potential of coconut fiber in removing cesium from radioactive liquid wastes; this process can help in disposing radioactive waste. The experiments were performed in batch and the particle size of the fiber ranged between 0.30 mm and 0.50 mm. The fiber was treated with hydrogen peroxide in alkaline medium. The following parameters were analyzed: contact time, pH and concentration of cesium ions in aqueous solution. After the experiments the samples were filtered and cesium remaining in solution was quantified by inductively coupled plasma optical emission spectrometry. (author)

  10. Radiochemical determination of strontium-90 and cesium-137 in waters of the Pacific Ocean and its neighboring seas

    International Nuclear Information System (INIS)

    Borisenko, G.S.; Kandinskii, P.A.; Gedeonov, L.I.; Ivanova, L.M.; Petrov, A.A.

    1987-01-01

    Depending on the salinity of the water, two versions of strontium-90 and cesium-137 concentration from water samples are presented. Cesium-137 was concentrated by precipitating sparingly soluble mixed hexacyanoferrates (II), and strontium-90 by precipitating carbonates together with calcium. A scheme has been given for radiochemical analysis of the concentrates. Strontium-90 and cesium-137 contents in the waters of the Pacific Ocean and its neighboring seas have been determined by the radiochemical method described. The levels of radionuclide content in the water and atmospheric precipitations have been shown to be inter-related. Strontium-90 and cesium-137 contents in the surface water of the northwestern Pacific were found to be much lower in 1980 than in the early seventies. The area of technogenic radioactive pollution was found to persist in the region of the Columbia mouth into the Pacific Ocean

  11. Analysis of cesium-137 vertical distribution in the profile of plowed chernozems at different schemes of their assaying

    International Nuclear Information System (INIS)

    Paramonova, T.A.; Komissarova, O.L.; Belyaev, V.R.; Ivanov, M.M.

    2016-01-01

    In 2011-2015 the assessment of profile cesium-137 distribution in agrocenosis of chernozem zone on the territory of the Plavsk radioactive spot in Tula region formed after the Chernobyl accident has been carried out. It is shown that up until now non-uniformity of cesium-137 vertical distribution over the plowed chernozems profile may be occurred, it should be taken into account at radioecological survey of post-Chernobyl landscapes. For correct evaluation of radioecological state of plowed soils their systematic monitoring on the base of preliminary analysis of cesium-137 distribution and also with the account of agrotechnical peculiarities of various crops cultivation is recommended. On the Plavsk radioactive spot territory the most adequate assessments of cesium-137 stores in plowed chernozems one can obtain on the base of assaying the upper 30-cm soil depth, including not only current topsoil, but also old-arable horizon formed by deep rehabilitation plowing [ru

  12. Investigation into the Effects of VHF and UHF Band Radiation on Hewlett-Packard (HP) Cesium Beam Frequency Standards

    National Research Council Canada - National Science Library

    Dickens, Andrew

    1994-01-01

    This paper documents an investigation into reports which have indicated that exposure to VHF and UHF band radiation has adverse effects on the frequency stability of HP cesium beam frequency standards...

  13. Strontium 90 and cesium 137 content in the daily diet of two groups of people in Plovdiv

    International Nuclear Information System (INIS)

    Babakova, I.; Trendafilov, I.; Todorov, D.

    1975-01-01

    The contents of strontium 90 and cesium 137 in the daily diet of children, 7-11 years old, and teenagers, 14-18 years old, living under boarding house conditions is determined. The daily strontium 90 intake in the organism of children and teenagers amounts to 9,78 pCi, respectively 17,96 pCi and the daily intake of cesium 137 - to 13,21 pCi, respectively 21,33 pCi. The bigger part of the strontium 90 and cesium 137 intake comes from the bread, accounting for 4,85 pCi stroncium 90 and 5,08 to 7,0 pCi cesium 137. (author)

  14. Removal of cesium using coconut fiber in raw and modified forms for the treatment of radioactive liquid wastes

    International Nuclear Information System (INIS)

    Jesus, Nella N.M. de; Nobre, Vanessa B.; Potiens Junior, Ademar J.; Sakata, Solange K.; Di Vitta, Patricia B.

    2013-01-01

    Sorption is one of the most studied methods to reduce the volume of radioactive waste streams. Cesium-137 is a radioisotope formed by the fission of uranium and it can cause health problems due to its easy assimilation by cells. The aim of this study is to evaluate the potential of coconut fiber in removing cesium from radioactive liquid wastes; this process can help in disposing radioactive waste. The experiments were performed in batch and the particle size of the fiber ranged between 0.30 mm and 0.50 mm. The fiber was treated with hydrogen peroxide in alkaline medium. The following parameters were analyzed: contact time, pH and concentration of cesium ions in aqueous solution. After the experiments the samples were filtered and cesium remaining in solution was quantified by inductively coupled plasma optical emission spectrometry. (author)

  15. Cesium-137 in ash from combustion of biofuels. Application of regulations from the Swedish Radiation Safety Authority; Cesium-137 i aska fraan foerbraenning av biobraenslen. Tillaempning av Straalsaekerhetsmyndighetens regler

    Energy Technology Data Exchange (ETDEWEB)

    Sjoeblom, Rolf (Tekedo AB, Nykoeping (SE))

    2009-03-19

    The Swedish Radiation Safety Authority, SSM, has issued an ordinance on ash contaminated with Cesium-137. It implies amongst other things that ash containing 0,5 - 10 kBq/kg Cesium-137 (so-called contaminated ash) can be used for geotechnical purposes provided that the content in a near-by well does not exceed 1 Bq/litre and that the increase in a near-by fish producing recipient does not exceed 0,1 Bq/litre. The initial plan with the presently reported work was to provide a compilation of how the ordinance for Cesium-137 can be applied in practical work. It became evident, however, in the course of the work that issues related to the co-variation between potassium and Cesium needed further investigation. As a result, the present report comprises also a compilation of this extended information search. Cesium-137 is present in ash as a result of the accident in a nuclear power reactor in Chernobyl in 1986 during which material having a very small grain size was spread to a high altitude. A few days later, Cesium-137 was deposited during rains over large parts of Sweden. This activity penetrated to a depth of one or a few decimetres during the course of the subsequent few days and weeks, after which it was partially taken up by plants and spread in the ecosystem. Section 2 has the character of a handbook. It provides basic information on radiation, and also about the ordinance and other material from the SSI. Section 3 comprises compilations of relevant international status of knowledge. This regards how potassium and Cesium behave in soil and ash, and also how spreading of Cesium can be modelled. Cesium behaves similarly to Potassium but with the difference that Cesium is bonded much more strongly to mineral soil and ash. Potassium and Cesium appears in soil in four different forms: dissolved in the pore water, exchangeable, non-exchangeable and as bonded to minerals. The amount dissolved in the pore water is the smallest and that bonded to minerals is the largest

  16. Elution of Artificial Sputum from Swab by Rotating Magnetic Field-Induced Mechanical Impingement

    Directory of Open Access Journals (Sweden)

    Shubham Banik

    2017-12-01

    Full Text Available Cotton-tipped applicator swabs are used as a collection device for many biological samples and its complete elution is a desired step for clinical and forensic diagnostics. Swabs are used to collect infectious body fluids, where the concentration of pathogens can range from 1 × 104 CFU/mL (colony forming units/mL in respiratory-tract infections and 1 × 105 in urinary-tract infections, to up to 1 × 109 CFU/mL in salivary samples. These samples are then eluted and lysed, prior to DNA (De-oxy Ribonucleic Acid analysis. The recovery of micro-organisms from a matrix of swab fibres depends on the nature of the body fluid, the type of the swab fibres, and the process of elution. Various methods to elute samples from swab include chemical digestion of fibres (~20% recovery, centrifugation (~58% recovery, piezoelectric vibration, or pressurized fluid-flow (~60% recovery. This study reports a magnetically-actuated physical impingement method for elution and recovery of artificial sputum samples from cotton fibres. A device has been fabricated to induce a rotating magnetic field on smaller magnetic particles in a vial that strikes the swab within a confined gap. Elution from the swab in this device was characterized using 2% Methyl cellulose in deionised water, loaded with fluorescent-tagged polystyrene beads and E. coli at various concentrations. The recovery efficiency was found to increase with both rotational speed and elution time, but plateaus after 400 RPM (Revolutions per minute and 120 s, respectively. At a higher concentration of polystyrene beads (5 × 108 particles/mL, a maximum recovery of ~85% was achieved. With lower concentration, (1 × 105 particles/mL the maximum efficiency (~92.8% was found to be almost twice of passive elution (46.7%. In the case of E. coli, the corresponding recovery efficiency at 3.35 × 105 CFU/mL is 90.4% at 500 RPM and 120 s. This elution method is expected to have a wide applicability in clinical diagnostics.

  17. The promotional effects of cesium promoter on higher alcohol synthesis from syngas over cesium-promoted Cu/ZnO/Al2O3 catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Jie; Cai, Qiuxia; Wan, Yan; Wan, Shaolong; Wang, Li; Lin, Jingdong; Mei, Donghai; Wang, Yong

    2016-09-02

    In this study, the promotional effects of cesium promoter on higher alcohol (C2+OH) synthesis from syngas over Cs-Cu/ZnO/Al2O3 catalysts were investigated using a combined experimental and theoretical density functional theory (DFT) calculation method. In the presence of cesium, the C2+OH productivity increases from 77.1 g•kgcat-1•h-1 to 157.3 g•kgcat-1•h-1 at 583 K due to the enhancement of the initial C–C bond formation. Detailed analysis of chain growth probabilities (CGPs) confirms that initial C–C bond formation is the rate-determining step in the temperature range of 543-583 K. Addition of cesium promoter significantly increases the productivities of 2-methyl-1-propanol, while the CGPs values (C3* to 2-methyl-C3*) is almost unaffected. With the assistance of cesium promoter, the CGPs of the initial C–C bond formation step (C1* to C2*) could be increased from 0.13 to 0.25 at 583 K. DFT calculations indicate that the initial C–C bond formation is mainly contributed by the HCO+HCO coupling reaction over the ZnCu(211) model surface. In the presence of the Cs2O, the stabilities of key reaction intermediates such as HCO and H2CO are enhanced which facilitates both HCO+HCO and HCO+H2CO coupling reaction steps with lower activation barriers over the Cs2O-ZnCu(211) surface. The promotional effects of cesium on the C2+OH productivity are also benefited from the competitive CH+HCO coupling reaction over CH hydrogenation that leads to lower alkane formation. In addition, Bader charge analysis suggests that the presence of cesium ions would facilitate the nucleophilic reaction between HCO and H2CO for initial C–C bond formation. This work was supported by the National Natural Science Foundation of China (No. 91545114 and No. 91545203). We appreciate the joint PhD scholarship support from the China Scholarship Council. The authors would also like to thank the support from Collaborative Innovation Center of Chemistry for Energy Materials (2011-iChEM). DM

  18. A simple and convenient gradient elution set-up and its application in the separation of rare earth elements

    International Nuclear Information System (INIS)

    Niu, Chungi; Yu, Decai; Yang, Fu

    1982-01-01

    The operation principles, construction flowsheet, and electronic control circuit of a gradient elution device are described. The device was used for the separation of rare earth elements, (Lu, Yb, Tm, Er, Ho, Y, Dy, Tb, Gd, Eu, Sm, Nd, Pr, Ce and La) on a polystyrene sulfonic acid cation exchanger by elution with hydroxyisobutyric acid. The gradient elution device was easy to operate reliable and could be used continuously for a long period of time [fr

  19. Elution strategies for reversed-phase high-performance liquid chromatography analysis of sucrose alkanoate regioisomers with charged aerosol detection

    DEFF Research Database (Denmark)

    Lie, Aleksander; Pedersen, Lars Haastrup

    2013-01-01

    A broad range of elution strategies for RP-HPLC analysis of sucrose alkanoate regioisomers with CAD was systematically evaluated. The HPLC analyses were investigated using design-of-experiments methodology and analysed by analysis of variance (ANOVA) and regression modelling. Isocratic elutions, ......L/min reduced RDm by 29% and analysis time by 6%, compared to isocratic elution at 38% acetonitrile with standard flow (1.0 mL/min)....

  20. Properties of human gonadotrophins eluted from human corpus luteum and mouse luteoma LH-HCG receptors

    International Nuclear Information System (INIS)

    Cole, F.E.; Arquembourg, P.C.; Rice, B.F.

    1977-01-01

    Studies were performed to try to determine if gonadotrophins are altered during their interaction with tissue receptors. Immunologic, electrophoretic and binding properties of lactoperoxidase labelled [ 125 I]HLH and [ 125 I]HCG were examined before and after elution from mouse lutomea and human corpora lutea receptor preparations. The anti-HCG used in these studies at a 1:10 000 dilution precipitated 92% of a freshly iodinated [ 125 I]HCG preparation. Receptor eluted [ 125 I]HCG, derived from the same batch of labelled ligand, was virtually quantitatively precipitated by the same dilution of anti-HCG. [ 125 I]HCG eluted from the human corpus luteum was electrophoretically more homogeneous when compared to its heterogenous parent labelled preparation and migrated to a position similar to that of native HCG. In Ouchterlony double diffusion experiments against anti-HCG antiserum, corpus lutheum eluted [ 125 I]HCG and [ 125 I]HLH showed immunologic identity with each other as well as with native HCG and HLH. Receptor eluted [ 125 I]HCG from the mouse luteoma, following in vivo administration via tail vein injection or after incubation in vitro with labelled hormones, was immunologically indistinguishable from native HCG. The electrophoretic mobility of HCG was retarded when HCG was added to extracts of mouse luteoma, liver and kidney. Eluates of mouse luteoma, applied to Bio-Gel columns previously equilibrated with [ 125 I]HCG showed the ability to concentrate [ 125 I]HCG in the high molecular weight column fractions. (author)

  1. Aluminum elution and precipitation in glass vials: effect of pH and buffer species.

    Science.gov (United States)

    Ogawa, Toru; Miyajima, Makoto; Wakiyama, Naoki; Terada, Katsuhide

    2015-02-01

    Inorganic extractables from glass vials may cause particle formation in the drug solution. In this study, the ability of eluting Al ion from borosilicate glass vials, and tendencies of precipitation containing Al were investigated using various pHs of phosphate, citrate, acetate and histidine buffer. Through heating, all of the buffers showed that Si and Al were eluted from glass vials in ratios almost the same as the composition of borosilicate glass, and the amounts of Al and Si from various buffer solutions at pH 7 were in the following order: citrate > phosphate > acetate > histidine. In addition, during storage after heating, the Al concentration at certain pHs of phosphate and acetate buffer solution decreased, suggesting the formation of particles containing Al. In citrate buffer, Al did not decrease in spite of the high elution amount. Considering that the solubility profile of aluminum oxide and the Al eluting profile of borosilicate glass were different, it is speculated that Al ion may be forced to leach into the buffer solution according to Si elution on the surface of glass vials. When Al ions were added to the buffer solutions, phosphate, acetate and histidine buffer showed a decrease of Al concentration during storage at a neutral range of pHs, indicating the formation of particles containing Al. In conclusion, it is suggested that phosphate buffer solution has higher possibility of forming particles containing Al than other buffer solutions.

  2. Innovative Elution Processes for Recovering Uranium and Transition Metals from Amidoxime-based Adsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Wai, Chien M. [Univ. of Idaho, Moscow, ID (United States). Dept. of Chemistry

    2017-04-18

    Amidoxime-based polymer fibers are considered one of the most promising materials for sequestering uranium from seawater. The high-surface-area polymer fibers containing amidoxime and carboxylate groups synthesized by Oak Ridge National Lab (ORNL-AF1) show very high uranium adsorption capacities known in the literature. Effective elution of uranium and repeated use of the adsorbent are important factors affecting the cost of producing uranium from seawater using this material. Traditional acid leaching of uranium followed by KOH conditioning of the fiber causes chemical changes and physical damage to the ORNL-AF1 adsorbent. Two alkaline solution leaching methods were developed by this project, one uses a highly concentrated (3 M) potassium bicarbonate solution at pH 8.3 and 40 °C; the other uses a mixture of sodium carbonate and hydrogen peroxide at pH 10.4. Both elution methods do not require KOH conditioning prior to reusing the fiber adsorbent. The conditions of eluting uranium from the amidoxime-based adsorbent using these alkaline solutions are confirmed by thermodynamic calculations. The bicarbonate elution method is selective for uranium recovery compared to other elution methods and causes no chemical change to the fiber material based on FTIR spectroscopy

  3. DNA Adsorption to and Elution from Silica Surfaces: Influence of Amino Acid Buffers

    Science.gov (United States)

    Vandeventer, Peter E.; Mejia, Jorge; Nadim, Ali; Johal, Malkiat S.; Niemz, Angelika

    2014-01-01

    Solid phase extraction and purification of DNA from complex samples typically requires chaotropic salts that can inhibit downstream polymerase amplification if carried into the elution buffer. Amino acid buffers may serve as a more compatible alternative for modulating the interaction between DNA and silica surfaces. We characterized DNA binding to silica surfaces, facilitated by representative amino acid buffers, and the subsequent elution of DNA from the silica surfaces. Through bulk depletion experiments, we found that more DNA adsorbs to silica particles out of positively compared to negatively charged amino acid buffers. Additionally, the type of the silica surface greatly influences the amount of DNA adsorbed, and the final elution yield. Quartz crystal microbalance experiments with dissipation monitoring (QCM-D) revealed multiphasic DNA adsorption out of stronger adsorbing conditions such as arginine, glycine, and glutamine, with DNA more rigidly bound during the early stages of the adsorption process. The DNA film adsorbed out of glutamate was more flexible and uniform throughout the adsorption process. QCM-D characterization of DNA elution from the silica surface indicates an uptake in water mass during the initial stage of DNA elution for the stronger adsorbing conditions, which suggests that for these conditions the DNA film is partly dehydrated during the prior adsorption process. Overall, several positively charged and polar neutral amino acid buffers show promise as an alternative to methods based on chaotropic salts for solid phase DNA extraction. PMID:23931415

  4. Biosorption of cesium by native and chemically modified biomass of marine algae: introduce the new biosorbents for biotechnology applications.

    Science.gov (United States)

    Jalali-Rad, R; Ghafourian, H; Asef, Y; Dalir, S T; Sahafipour, M H; Gharanjik, B M

    2004-12-10

    Biosorption batch experiments were conducted to determine the cesium binding ability of native biomass and chemically modified biosorbents derived from marine algae, namely ferrocyanide algal sorbents type 1 and type 2 (FASs1 and FASs2). The applicability of the Langmuir and Freundlich isotherms for representation of the experimental data was investigated. The cesium sorption performances of the various types of sorbents were compared using the maximum capacities (qmax values) obtained from fitting the Langmuir isotherm to the values calculated from the sorption experiments, which FASs type 1 and type 2 showed better sorption performances for cesium. FASs1 and FASs2 derived from formaldehyde and glutaraldehyde crosslinked Padina australis exhibited lower sorption capacities than those prepared from the non-crosslinked one. Most of the cesium ions were bound to FASs1, derived from Sargassum glaucescens and P. australis, in australis and Cystoseria indica was constantly occurred at a wide range of pH, between 1 and 10, and the highest removal took place at pH 4. The presence of sodium and potassium at 0.5 and 1mM did not inhibit cesium biosorption by algae biomass. The maximum cesium uptake was acquired using the large particles of FAS2 originated from S. glaucescens (2-4 mm). Desorption of cesium from the metal-laden FASs1 (from P. australis, S. glaucescens and Dictyota indica) was completely achieved applying 0.5 and 1 M NaOH and KOH, although the cesium sorption capacity of the biosorbents (from C. indica and S. glaucescens) decreased by 46-51% after 9 sorption-desorption cycles.

  5. Synthesis and leachability study of a new cesium immobilized langbeinite phosphate: KCsFeZrP3O12

    International Nuclear Information System (INIS)

    Kumar, Sathasivam Pratheep; Gopal, Buvaneswari

    2014-01-01

    Highlights: • Synthesis of novel potassium cesium iron zirconium phosphate by simple solution method. • Characterization of the compound by various spectroscopic techniques. • Immobilization of cesium into the langbeinite structure with negligible leachability of cesium. • Comparative leachability study of cesium immobilized langbeinite phosphate and sodium zirconium phosphate. - Abstract: A potassium cesium iron zirconium phosphate, KCsFeZrP 3 O 12 , was synthesized by simple solution method for the first time. Powder X-ray diffraction analysis confirmed that the compound crystallizes in cubic langbeinite structure (space group: P2 1 3) with the cell parameters of a = 10.103 (2) Å and V = 1031 Å 3 . Fourier transform infrared spectrum showed the stretching and bending vibrational bands of phosphate tetrahedra. Energy dispersive X-ray analysis proved the presence of elements. Leachability of a powder specimen was studied by MCC-5 test for a period of one month. Inductive coupled plasma and atomic absorption spectroscopic results revealed the negligible leaching of cesium. The normalized mass loss of potassium, iron, zirconium and phosphorous were found to be in the order of 10 −4 –10 −3 g/m 2 , 10 −6 –10 −4 g/m 2 , 10 −5 –10 −3 g/m 2 and 10 −4 –10 −3 g/m 2 respectively. For comparison, a cesium zirconium phosphate (CsZr 2 P 3 O 12 ) with the sodium zirconium phosphate structure was synthesized, and its leach rates of zirconium and phosphorous were comparable to those of the langbeinite phase. The cesium leach rate was negligible for both compounds

  6. Entrapment of 137Cs vapour generated during vitrification and casting of cesium borosilicate glass by inorganic materials

    International Nuclear Information System (INIS)

    Ram, Ramu; Gandhi, Shyamala; Dash, A.; Varma, R.N.

    2003-01-01

    Efficiency of different inorganic materials like zirconium antimonate (ZrA), ammonium molybdophosphate (AMP), synthetic zeolites, activated charcoal, glass wool etc, towards the entrapment of 137 Cs vapour escaping during vitrification and casting of cesium borosilicate glass required for the preparation of 137 Cs sources for medical and industrial applications have been determined. The recovery of entrapped cesium using dilute acids for subsequent recycling has also been explored. (author)

  7. 3-Year clinical outcomes in the randomized SORT OUT III superiority trial comparing zotarolimus- and sirolimus-eluting coronary stents

    DEFF Research Database (Denmark)

    Maeng, Michael; Tilsted, Hans-Henrik; Jensen, Lisette Okkels

    2012-01-01

    This study sought to examine the 3-year clinical outcomes in patients treated with the Endeavor (Medtronic, Santa Rosa, California) zotarolimus-eluting stent (ZES) or the Cypher (Cordis, Johnson & Johnson, Warren, New Jersey) sirolimus-eluting stent (SES) in routine clinical practice.......This study sought to examine the 3-year clinical outcomes in patients treated with the Endeavor (Medtronic, Santa Rosa, California) zotarolimus-eluting stent (ZES) or the Cypher (Cordis, Johnson & Johnson, Warren, New Jersey) sirolimus-eluting stent (SES) in routine clinical practice....

  8. Analysis of the role of elution buffers on the separation capabilities of dielectrophoretic devices

    Directory of Open Access Journals (Sweden)

    Rossana Di Martino

    2016-03-01

    Full Text Available Field flow fractionation dielectrophoretic (FFF-DEP devices are currently used, among the others, for the separation of tumor cells from healthy blood cells. To this end specific suspension/elution buffers (EBs, with reduced conductivity (with respect to that of the cell cytoplasm are generally used. In this paper we investigate the long-term alterations of the cells and elution buffers. We find that the EB conductivity is critically modified within few minutes after cells suspension. In turn, this modification results in a change the ideal separation frequency of the FFF-DEP device. On the other hand we prove that DEP manipulation is preserved for more than three hours for cells suspended in the considered EBs. Keywords: Dielectrophoresis, Elution buffer, Circulating tumor cells, Cell motility

  9. Modulator Dynamics Shape the Design Space for Stepwise-Elution Simulated Moving Bed Chromatographic Separations.

    Science.gov (United States)

    Wayne, Chris J; Velayudhan, Ajoy

    2018-03-31

    For proteins and other biological macromolecules, SMB chromatography is best operated non-isocratically. However, traditional modes of non-isocratic SMB operation generate significant mobile-phase modulator dynamics. The mechanisms by which these modulator dynamics affect a separation's success, and thus frame the design space, have yet to be explained quantitatively. Here, the dynamics of the modulator (e.g. salts in ion exchange and hydrophobic interaction chromatography) are explicitly accounted for. This leads to the elucidation of two new design constraints, presented as dimensionless numbers, which quantify the effects of the modulator phenomena and thus predict the success of a non-isocratic SMB separation. Consequently, these two new design constraints re-define the SMB design space. Computational and experimental studies at the boundaries of this design space corroborate the theoretical predictions. The design of efficient and robust operating conditions through use of the new design space is also demonstrated. This article is protected by copyright. All rights reserved.

  10. Final five-year outcomes after implantation of biodegradable polymer-coated biolimus-eluting stents versus durable polymer-coated sirolimus-eluting stents

    DEFF Research Database (Denmark)

    Jakobsen, Lars; Christiansen, Evald H; Maeng, Michael

    2017-01-01

    AIMS: Our aim was to report the long-term safety and efficacy of the biodegradable polymer-coated biolimus- eluting Nobori stent compared to the durable polymer-coated sirolimus-eluting CYPHER stent. METHODS AND RESULTS: SORT OUT V randomised 2,468 patients 1:1 to the Nobori (n=1,229) versus...... also found to be similar in patients treated with the two study stents (Nobori 23/1,229 [1.9%] vs. CYPHER 18/1,239 [1.5%]; OR 1.31, 95% CI: 0.70-2.47; p=0.40), as were the other secondary endpoints. CONCLUSIONS: At five-year follow-up, the Nobori stent with a biodegradable polymer coating provided...... a similar safety and efficacy profile when compared to the durable polymer first-generation CYPHER stent....

  11. Outcome of Sirolimus-Eluting Versus Zotarolimus-Eluting Coronary Stent Implantation in Patients With and Without Diabetes Mellitus (a SORT OUT III Substudy)

    DEFF Research Database (Denmark)

    Maeng, Michael; Jensen, Lisette O; Tilsted, Hans-Henrik

    2011-01-01

    Diabetes is associated with an increased risk of major adverse cardiac events after percutaneous coronary intervention. We compared clinical outcomes in patients with and without diabetes mellitus treated with the second-generation Endeavor zotarolimus-eluting stent (ZES) or the first......-generation Cypher Select+ sirolimus-eluting stent (SES). We randomized 2,332 patients to treatment with ZESs (n = 1,162, n = 169 diabetics) or SESs (n = 1,170, n = 168 diabetics) and followed them for 18 months. Randomization was stratified by presence/absence of diabetes. The primary end point was major adverse...... cardiac events defined as a composite of cardiac death, myocardial infarction, or target vessel revascularization. Secondary end points included these individual end points plus all-cause mortality and target lesion revascularization. In diabetic patients, use of ZES compared to SES was associated...

  12. Effect of Post-Dilatation Following Primary PCI With Everolimus-Eluting Bioresorbable Scaffold Versus Everolimus-Eluting Metallic Stent Implantation

    DEFF Research Database (Denmark)

    Yamaji, Kyohei; Brugaletta, Salvatore; Sabaté, Manel

    2017-01-01

    OBJECTIVES: This study sought to investigate the effect of post-dilatation on angiographic and intracoronary imaging parameters in the setting of primary percutaneous coronary intervention comparing the everolimus-eluting bioresorbable scaffold (BRS) with the everolimus-eluting metallic stent (EES......). BACKGROUND: Routine post-dilatation of BRS has been suggested to improve post-procedural angiographic and subsequent device-related clinical outcomes. METHODS: In the ABSORB STEMI TROFI II trial, 191 patients with ST-segment elevation myocardial infarction were randomly assigned to treatment with BRS (n = 95......) or EES (n = 96). Minimal lumen area and healing score as assessed by optical coherence tomography at 6 months were compared between BRS- and EES-treated patients stratified according to post-dilatation status. RESULTS: Primary percutaneous coronary intervention with post-dilatation was performed in 48...

  13. Differential clinical outcomes after 1 year versus 5 years in a randomised comparison of zotarolimus-eluting and sirolimus-eluting coronary stents (the SORT OUT III study)

    DEFF Research Database (Denmark)

    Maeng, Michael; Tilsted, Hans Henrik; Jensen, Lisette Okkels

    2014-01-01

    allocation service. The primary endpoint of the SORT OUT III study was a composite of major adverse cardiac events-cardiac death, myocardial infarction, and target vessel revascularisation-at 9 months' follow-up. In this study, endpoints included the occurrence of major adverse cardiac events and definite...... stent thrombosis at follow-up times of up to 5 years. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00660478. FINDINGS: We randomly allocated 1162 patients to receive the zotarolimus-eluting stent and 1170 to the sirolimus-eluting stent. At 5-year follow...... for rates of major adverse cardiac events at 1-year follow up (zotarolimus 93/1162 [8.0%] vs sirolimus 46/1170 [3.9%]; OR 2.13, 95% CI 1.48-3.07; pdefinite...

  14. Determination of microquantities of cesium in leaching tests by atomic absorption spectrometry with electrothermal atomization

    International Nuclear Information System (INIS)

    Crubellati, R.O.; Di Santo, N.R.

    1988-01-01

    An original method for cesium determinations by atomic absorption spectrometry with electrothermal atomization is described. The effect of foreign ions (alkali and earth alkaline metals) present in leaching test of glasses with incorporated radioactive wastes was studied. The effect of different mineral acids was also investigated. A comparison between the flame excitation method and the electrothermal atomization one was made. Under optimum conditions, cesium in quantities down to 700 ng in 1000 ml of sample could be determined. The calibration curve was linear in the range of 0.7 - 15 ng/mL. The fact that the proposed determinations can be performed in a short time and that a small sample volume is required are fundamental advantages of this method, compared with the flame excitation procedure. Besides, it is adaptable to be applied in hot cells and glove boxes. (Author) [es

  15. A model for cesium-137 tranfer in the compartments of a simplified freshwater ecosystem

    International Nuclear Information System (INIS)

    Lambrechts, A.

    1984-05-01

    Cesium-137 transfer was monitored in an experimental ecosystem comprising water, sediment, a benthic organism (midge larvae), a macroplankton (waterfleas) and a fish (carp). A transfer equation was derived from experimentation at each exchange level. It was shown experimentally that these exchanges are cumulative, and their equations can be integrated in a model that takes account of the quantity and quality of the food uptake; the biological half-life and the fish growth. The model reveals the influence of factors such as the contamination duration, or the age and dietary habits of the fish; it can be used to predict their activity level according to the activity of the water, and shows the relative importance of the contamination vectors. The calculated results are coherent with the cesium content measured in fish in the Rhone river [fr

  16. Hyperfine structure, nuclear spins and magnetic moments of some cesium isotopes

    International Nuclear Information System (INIS)

    Ekstroem, C.; Ingelman, S.; Wannberg, G.

    1977-03-01

    Using an atomic-beam magnetic resonance apparatus connected on-line with the ISOLDE isotope separator, CERN, hyperfine structure measurements have been performed in the 2 Ssub(1/2) electronic ground state of some cesium isotopes. An on-line oven system which efficiently converts a mass separated ion-beam of alkali isotopes to an atomic beam is described in some detail. Experimentally determined nuclear spins of sup(120, 121, 121m, 122, 122m, 123, 124, 126, 128, 130m, 135m)Cs and magnetic moments of sup(122, 123, 124, 126, 128, 130)Cs are reported and discussed in terms of different nuclear models. The experimental data indicate deformed nuclear shapes of the lightest cesium isotopes. (Auth.)

  17. An expander system of high stable laser beam for cesium atomic fountain clocks

    Science.gov (United States)

    Chen, Jiang; Lin, Rui; Liu, Dandan; Zhang, Hui; Ruan, Jun; Shi, Junru; Yu, Fengxiang; Zhang, Shougang

    2017-10-01

    The quality of the cold atoms sample plays an important role to improve the performance of cesium atomic fountain clocks. The preparation of cold atoms sample has a strict requirement for cooling lasers characteristics such as power stability, polarization, collimation, uniformity and verticality. This work implements a design of an expander system of high stable laser beam for the cold atom preparation. The cooling laser characteristics can be adjusted by the design, and the use of non-magnetic materials to avoid the magnetic field on the impact of cold atom. The cold atom sample with the number of 2×108 and temperature of 5μk was obtained by expander system. The result meets the requirements of the preparation of cold atoms for cesium atomic fountain clocks.

  18. Adsorption isotherms for cesium ions in seawater of insoluble cobalt and nickel ferrocyanide-impregnated fibers

    International Nuclear Information System (INIS)

    Amakai, Wataru; Sugiyama, Mai; Fujiwara, Kunio; Umeno, Daisuke; Saito, Kyoichi; Sugo, Takanobu

    2014-01-01

    Cobalt or nickel ferrocyanide was impregnated into an anion-exchange polymer chain grafted onto a commercially available 6-nylon fiber. First, ferrocyanide ions (Fe(CN) 6 4- ) were bound to the anion-exchange fiber. Second, the fiber was made to reach with cobalt or nickel ions to form insoluble cobalt or nickel ferrocyanide via precipitation. For comparison, a commercially available anion-exchange bead was used as a support for the impregnation of insoluble cobalt or nickel ferrocyanide. The contents of metal ferrocyanides impregnated onto the fiber were approximately half those impregnated onto the bead. Adsorption isotherms of insoluble cobalt or nickel ferro-cyanide-impregnated fiber and bead for cesium ions in seawater correlated well with a Langmuir-type isotherm. The saturation capacity for cesium ions in seawater per gram of insoluble metal ferrocyanides was almost identical between the fiber and the bead. (author)

  19. Influence of metallic silver and oxygen on the radiolysis of cesium iodide solutions

    International Nuclear Information System (INIS)

    Furrer, M.; Gloor, T.

    1988-01-01

    Silver iodide formation by radiolysis has been studied in the system water/cesium iodide/silver metal. In a number of scenarios for hypothetical core melt accidents, silver iodide has been considered as an effective scavenger for fission product iodine. The influence of dissolved oxygen and the consequences of a variable silver/cesium iodide ratio are shown in detail. Partial kinetic reaction constants for the different parameters are presented and it is shown that they can be simply added together to form an overall reaction rate constant. In a radiation field just short of 5 kGy/h, the influences of oxygen (air) and of the radiation are of the same order of magnitude. A linear relation is shown between specific metal surface and reaction rates. Data shown are compatible with earlier measurements made at Oak Ridge National Laboratory, US

  20. Improvement of Laser Frequency Stabilization for the Optical Pumping Cesium Beam Standard

    International Nuclear Information System (INIS)

    Wang Qing; Duan Jun; Qi Xiang-Hui; Zhang Yin; Chen Xu-Zong

    2015-01-01

    A method is presented to improve the laser frequency stabilization for the optical pumping cesium clock. By comparing the laser frequency stabilization of different schemes, we verify that the light angle is an important factor that limits the long-term frequency stability. We minimize the drift of the light angle by using a fiber-coupled output, and lock the frequency of a distributed-feedback diode laser to the fluorescence spectrum of the atomic beam. The measured frequency stability is about 3.5 × 10 −11 at 1 s and reaches 1.5 × 10 −12 at 2000 s. The Allan variance keeps going down for up to thousands of seconds, indicating that the medium- and long-term stability of the laser frequency is significantly improved and perfectly fulfills the requirement for the optical pumping cesium clock. (paper)