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Sample records for stable barium carbonate

  1. Barium carbonate as an agent to improve the electrical properties of neodymium-barium-copper system at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, J.P. [Post-Graduate Program in Chemical Engineering, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, 88040-900 (Brazil); Duarte, G.W. [Post-Graduate Program in Chemical Engineering, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, 88040-900 (Brazil); Research Group in Technology and Information, Centro Universitário Barriga Verde (UNIBAVE), Santa Catarina, SC (Brazil); Caldart, C. [Post-Graduate Program in Science and Materials Engineering, Universidade do Extremo Sul Catarinense (UNESC), Criciúma, SC, 88806-000 (Brazil); Kniess, C.T. [Post-Graduate Program in Professional Master in Management, Universidade Nove de Julho, São Paulo, SP (Brazil); Montedo, O.R.K.; Rocha, M.R. [Post-Graduate Program in Science and Materials Engineering, Universidade do Extremo Sul Catarinense (UNESC), Criciúma, SC, 88806-000 (Brazil); Riella, H.G. [Post-Graduate Program in Chemical Engineering, Universidade Federal de Santa Catarina (UFSC), Florianópolis, SC, 88040-900 (Brazil); Fiori, M.A., E-mail: fiori@unochapeco.edu.br [Post-Graduate Program in Environmental Science, Universidade Comunitária da Região de Chapecó (UNOCHAPECÓ), Chapecó, SC, 89809-000 (Brazil); Post-Graduate Program in Technology and Management of the Innovation, Universidade Comunitária da Região de Chapecó (UNOCHAPECÓ), Chapecó, SC, 89809-000 (Brazil)

    2015-11-15

    Specialized ceramics are manufactured under special conditions and contain specific elements. They possess unique electrical and thermal properties and are frequently used by the electronics industry. Ceramics containing neodymium-barium-copper (NBC) exhibit high conductivities at low temperatures. NBC-based ceramics are typically combined with oxides, i.e., NBCo produced from neodymium oxide, barium oxide and copper oxide. This study presents NBC ceramics that were produced with barium carbonate, copper oxide and neodymium oxide (NBCa) as starting materials. These ceramics have good electrical conductivities at room temperature. Their conductivities are temperature dependent and related to the starting amount of barium carbonate (w%). - Highlights: • The new crystalline structure were obtained due presence of the barium carbonate. • The NBCa compound has excellent electrical conductivity at room temperature. • The grain crystalline morphology was modified by presence of the barium carbonate. • New Phases α and β were introduced by carbonate barium in the NBC compound.

  2. Barium carbonate as an agent to improve the electrical properties of neodymium-barium-copper system at high temperature

    International Nuclear Information System (INIS)

    Fernandes, J.P.; Duarte, G.W.; Caldart, C.; Kniess, C.T.; Montedo, O.R.K.; Rocha, M.R.; Riella, H.G.; Fiori, M.A.

    2015-01-01

    Specialized ceramics are manufactured under special conditions and contain specific elements. They possess unique electrical and thermal properties and are frequently used by the electronics industry. Ceramics containing neodymium-barium-copper (NBC) exhibit high conductivities at low temperatures. NBC-based ceramics are typically combined with oxides, i.e., NBCo produced from neodymium oxide, barium oxide and copper oxide. This study presents NBC ceramics that were produced with barium carbonate, copper oxide and neodymium oxide (NBCa) as starting materials. These ceramics have good electrical conductivities at room temperature. Their conductivities are temperature dependent and related to the starting amount of barium carbonate (w%). - Highlights: • The new crystalline structure were obtained due presence of the barium carbonate. • The NBCa compound has excellent electrical conductivity at room temperature. • The grain crystalline morphology was modified by presence of the barium carbonate. • New Phases α and β were introduced by carbonate barium in the NBC compound

  3. Barium isotope fractionation during experimental formation of the double carbonate BaMn[CO3](2) at ambient temperature.

    Science.gov (United States)

    Böttcher, Michael E; Geprägs, Patrizia; Neubert, Nadja; von Allmen, Katja; Pretet, Chloé; Samankassou, Elias; Nägler, Thomas F

    2012-09-01

    In this study, we present the first experimental results for stable barium (Ba) isotope ((137)Ba/(134)Ba) fractionation during low-temperature formation of the anhydrous double carbonate BaMn[CO(3)](2). This investigation is part of an ongoing work on Ba fractionation in the natural barium cycle. Precipitation at a temperature of 21±1°C leads to an enrichment of the lighter Ba isotope described by an enrichment factor of-0.11±0.06‰ in the double carbonate than in an aqueous barium-manganese(II) chloride/sodium bicarbonate solution, which is within the range of previous reports for synthetic pure BaCO (3) (witherite) formation.

  4. New efficient catalyst for ammonia synthesis: barium-promoted cobalt on carbon

    DEFF Research Database (Denmark)

    Hagen, Stefan; Barfod, Rasmus; Fehrmann, Rasmus

    2002-01-01

    Barium-promoted cobalt catalysts supported on carbon exhibit higher ammonia activities at synthesis temperatures than the commercial, multipromoted iron catalyst and also a lower ammonia......Barium-promoted cobalt catalysts supported on carbon exhibit higher ammonia activities at synthesis temperatures than the commercial, multipromoted iron catalyst and also a lower ammonia...

  5. Regeneration of barium carbonate from barium sulphide in a pilot-scale bubbling column reactor and utilization for acid mine drainage

    CSIR Research Space (South Africa)

    Mulopo, J

    2012-01-01

    Full Text Available Batch regeneration of barium carbonate (BaCO3) from barium sulphide (BaS) slurries by passing CO2 gas into a pilot-scale bubbling column reactor under ambient conditions was used to assess the technical feasibility of BaCO3 recovery in the Alkali...

  6. Regeneration of barium carbonate from barium sulphide in a pilot-scale bubbling column reactor and utilization for acid mine drainage.

    Science.gov (United States)

    Mulopo, J; Zvimba, J N; Swanepoel, H; Bologo, L T; Maree, J

    2012-01-01

    Batch regeneration of barium carbonate (BaCO(3)) from barium sulphide (BaS) slurries by passing CO(2) gas into a pilot-scale bubbling column reactor under ambient conditions was used to assess the technical feasibility of BaCO(3) recovery in the Alkali Barium Calcium (ABC) desalination process and its use for sulphate removal from high sulphate Acid Mine Drainage (AMD). The effect of key process parameters, such as BaS slurry concentration and CO(2) flow rate on the carbonation, as well as the extent of sulphate removal from AMD using the recovered BaCO(3) were investigated. It was observed that the carbonation reaction rate for BaCO(3) regeneration in a bubbling column reactor significantly increased with increase in carbon dioxide (CO(2)) flow rate whereas the BaS slurry content within the range 5-10% slurry content did not significantly affect the carbonation rate. The CO(2) flow rate also had an impact on the BaCO(3) morphology. The BaCO(3) recovered from the pilot-scale bubbling column reactor demonstrated effective sulphate removal ability during AMD treatment compared with commercial BaCO(3).

  7. Spectrophotometry of barium, CH, and R-type carbon stars

    International Nuclear Information System (INIS)

    Gow, C.E.

    1976-01-01

    Observations of 35 barium, CH, R, and hydrogen-deficient carbon stars, along with ten comparison K giants, have been made with the Indiana rapid spectrum scanner and the Indiana SIT vidicon spectrometer. The scanner observations cover a wavelength range of 3300--7000 A at 30-A resolution, while the SIT vidicon observations cover a wavelength range of 3800--5000 A at 2.5-A resolution. The data have been used to form molecular indices for a quantitative measurement of the strength of molecular features appearing in this region of the spectrum, and to compare the spectral energy distribution of carbon and oxygen stars over the entire observed wavelength range. We find the C 2 Swan index correlated strongly with both the strength of an unidentified feature centered near 4000 A, and the barium-to-hydrogen ratio. A detailed comparison of the spectral energy distribution of the barium stars with normal K giants shows that this unidentified absorption feature consists of two shallows depressions, one at 4000 A and another at 4325 A

  8. Modeling and minimization of barium sulfate scale

    Science.gov (United States)

    Alan W. Rudie; Peter W. Hart

    2006-01-01

    The majority of the barium present in the pulping process exits the digester as barium carbonate. Barium carbonate dissolves in the bleach plant when the pH drops below 7 and, if barium and sulfate concentrations are too high, begins to precipitate as barium sulfate. Barium is difficult to control because a mill cannot avoid this carbonate-to-sulfate transition using...

  9. Electromagnetic properties of carbon black and barium titanate composite materials

    International Nuclear Information System (INIS)

    Wang Guiqin; Chen Xiaodong; Duan Yuping; Liu Shunhua

    2008-01-01

    Nanocrystalline carbon black/barium titanate compound particle (CP) was synthesized by sol-gel method. The phase structure and morphology of compound particle were investigated by X-ray diffraction (XRD), transmission electron microscope (TEM) and Raman spectrum measurements, the electroconductivity was test by trielectrode arrangement and the precursor powder was followed by differential scanning calorimetric measurements (DSC) and thermal gravimetric analysis (TGA). In addition, the complex relative permittivity and permeability of compound particle were investigated by reflection method. The compound particle/epoxide resin composite (CP/EP) with different contents of CP were measured. The results show barium titanate crystal is tetragonal phase and its grain is oval shape with 80-100 nm which was coated by carbon black film. As electromagnetic (EM) complex permittivity, permeability and reflection loss (RL) shown that the compound particle is mainly a kind of electric and dielectric lossy materials and exhibits excellent microwave absorption performance in the X- and Ku-bands

  10. Ammonia synthesis with barium-promoted iron–cobalt alloys supported on carbon

    DEFF Research Database (Denmark)

    Hagen, Stefan; Barfod, Rasmus; Fehrmann, Rasmus

    2003-01-01

    Iron–cobalt alloys supported on carbon were investigated as ammonia synthesis catalysts. Barium was found to have a promoting effect for Fe with an optimum atomic ratio Ba/Fe of 0.35. At this Ba loading, a local maximum for the NH3 synthesis activity was found at 4 wt% Co by varying the Fe/Co ratio....... Samples containing only Co and no Fe, however, yielded by far the most active catalysts (7.0 μmol (NH3) g−1 s−1, 673 K, 10 bar). Barium was a very efficient promoter for Co, increasing the NH3 synthesis activity by more than two orders of magnitude compared to the unpromoted Co samples, while...

  11. Sulphate removal from sodium sulphate-rich brine and recovery of barium as a barium salt mixture.

    Science.gov (United States)

    Vadapalli, Viswanath R K; Zvimba, John N; Mulopo, Jean; Motaung, Solly

    2013-01-01

    Sulphate removal from sodium sulphate-rich brine using barium hydroxide and recovery of the barium salts has been investigated. The sodium sulphate-rich brine treated with different dosages of barium hydroxide to precipitate barium sulphate showed sulphate removal from 13.5 g/L to less than 400 mg/L over 60 min using a barium to sulphate molar ratio of 1.1. The thermal conversion of precipitated barium sulphate to barium sulphide achieved a conversion yield of 85% using coal as both a reducing agent and an energy source. The recovery of a pure mixture of barium salts from barium sulphide, which involved dissolution of barium sulphide and reaction with ammonium hydroxide resulted in recovery of a mixture of barium carbonate (62%) and barium hydroxide (38%), which is a critical input raw material for barium salts based acid mine drainage (AMD) desalination technologies. Under alkaline conditions of this barium salt mixture recovery process, ammonia gas is given off, while hydrogen sulfide is retained in solution as bisulfide species, and this provides basis for ammonium hydroxide separation and recovery for reuse, with hydrogen sulfide also recoverable for further industrial applications such as sulfur production by subsequent stripping.

  12. An easily sintered, chemically stable, barium zirconate-based proton conductor for high-performance proton-conducting solid oxide fuel cells

    KAUST Repository

    Sun, Wenping; Shi, Zhen; Liu, Mingfei; Bi, Lei; Liu, Wei

    2014-01-01

    Yttrium and indium co-doped barium zirconate is investigated to develop a chemically stable and sintering active proton conductor for solid oxide fuel cells (SOFCs). BaZr0.8Y0.2-xInxO3- δ possesses a pure cubic perovskite structure. The sintering

  13. Growth behaviour of twisted ribbons of barium carbonate/silica self-assembled ceramics

    International Nuclear Information System (INIS)

    Garcia-Ruiz, J.M.; Moreno, A.

    1997-01-01

    Twisted ribbons of self-assembled crystal aggregates of barium carbonate, in the presence of silicate ions at pH 9.5 grow at constant rate between 20 and 50 mu m/min. The morphological behaviour depends on temperature, while it was demonstrated to be independent of the viscosity of the growth environment. (Author) 7 refs

  14. Analysis of barium hydroxide and calcium hydroxide slurry carbonation reactors

    International Nuclear Information System (INIS)

    Patch, K.D.; Hart, R.P.; Schumacher, W.A.

    1980-05-01

    The removal of CO 2 from air was investigated by using a continuous-agitated-slurry carbonation reactor containing either barium hydroxide [Ba(OH) 2 ] or calcium hydroxide [Ca(OH) 2 ]. Such a process would be applied to scrub 14 CO 2 from stack gases at nuclear-fuel reprocessing plants. Decontamination factors were characterized for reactor conditions which could alter hydrodynamic behavior. An attempt was made to characterize reactor performance with models assuming both plug flow and various degrees of backmixing in the gas phase. The Ba(OH) 2 slurry enabled increased conversion, but apparently the process was controlled under some conditions by phenomena differing from those observed for carbonation by Ca(OH) 2 . Overall reaction mechanisms are postulated

  15. Atomization of magnesium, strontium, barium and lead nitrates on surface of graphite atomizers

    International Nuclear Information System (INIS)

    Nagdaev, V.K.; Pupyshev, A.A.

    1982-01-01

    Modelling of the processes on graphite surface using differential-thermal analysis and graphite core with identification of decomposition products of magnesium, strontium, barium and lead nitrates by X-ray analysis has shown that carbon promotes the formation of strontium, barium and lead carbonates. The obtained temperatures of strontium and barium carbonate decomposition to oxides agree satisfactorily with calculation ones. Magnesium nitrate does not react with carbon. Formation of strontium and barium carbonates results in considerable slowing down of the process of gaseous oxide dissociation. Lead carbonate is unstable and rapidly decomposes to oxide with subsequent reduction to free metal. Formation of magnesium, strontium and barium free atoms is connected with appearance of gaseous oxides in analytical zone. Oxide and free metal lead are present on graphite surface simultaneously

  16. Barium hexaferrite nanoparticles: Synthesis and magnetic properties

    International Nuclear Information System (INIS)

    Martirosyan, K.S.; Galstyan, E.; Hossain, S.M.; Wang Yiju; Litvinov, D.

    2011-01-01

    Carbon combustion synthesis is applied to rapid and energy efficient fabrication of crystalline barium hexaferrite nanoparticles with the average particle size of 50-100 nm. In this method, the exothermic oxidation of carbon nanoparticles with an average size of 5 nm with a surface area of 80 m 2 /g generates a self-propagating thermal wave with maximum temperatures of up to 1000 deg. C. The thermal front rapidly propagates through the mixture of solid reactants converting it to the hexagonal barium ferrite. Carbon is not incorporated in the product and is emitted from the reaction zone as a gaseous CO 2 . The activation energy for carbon combustion synthesis of BaFe 12 O 19 was estimated to be 98 kJ/mol. A complete conversion to hexagonal barium ferrite is obtained for carbon concentration exceeding 11 wt.%. The magnetic properties H c ∼3000 Oe and M s ∼50.3 emu/g of the compact sintered ferrites compare well with those produced by other synthesis methods.

  17. Atomization mechanisms for barium in furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Styris, D.L.

    1984-01-01

    Atomic absorption spectrometry and mass spectrometry are used simultaneously in order to elucidate atomization mechanisms of barium dichloride in pyrolytic graphite, vitreous carbon, and tantalum furnaces. Gas-phase barium dicarbide is observed to appear concurrently with the free barium. Barium oxide and barium dihydroxide precursors appear with the chlorides. Surface reactions involving species that are absorbed on the various furnaces are postulated to explain the appearances of the species that are observed in the gas phase. 49 references, 4 figures, 1 table

  18. Thermal reactions of some calcium, strontium, and barium chromates

    International Nuclear Information System (INIS)

    Piekarska-Piesse, B.; Gontarz, Z.; Ostrowski, A.; Kucharski, R.

    2000-01-01

    Thermal decomposition of calcium chromates and solid state reactions of barium and strontium chromates(VI) with barium and strontium hydroxides and carbonates, as well as the reduction of chromates by carbon and hydrogen, have been investigated. The mechanisms of individual stages of the thermal decomposition have been proposed on the basis of morphological classification. (author)

  19. Preparation of meta-stable phases of barium titanate by Sol-hydrothermal method

    Directory of Open Access Journals (Sweden)

    Mahalakshmi Selvaraj

    2015-11-01

    Full Text Available Two low-cost chemical methods of sol–gel and the hydrothermal process have been strategically combined to fabricate barium titanate (BaTiO3 nanopowders. This method was tested for various synthesis temperatures (100 °C to 250 °C employing barium dichloride (BaCl2 and titanium tetrachloride (TiCl4 as precursors and sodium hydroxide (NaOH as mineralizer for synthesis of BaTiO3 nanopowders. The as-prepared BaTiO3 powders were investigated for structural characteristics using x-ray diffraction (XRD, scanning electron microscopy (SEM and transmission electron microscopy (TEM. The overall analysis indicates that the hydrothermal conditions create a gentle environment to promote the formation of crystalline phase directly from amorphous phase at the very low processing temperatures investigated. XRD analysis showed phase transitions from cubic - tetragonal - orthorhombic - rhombohedral with increasing synthesis temperature and calculated grain sizes were 34 – 38 nm (using the Scherrer formula. SEM and TEM analysis verified that the BaTiO3 nanopowders synthesized by this method were spherical in shape and about 114 - 170 nm in size. The particle distribution in both SEM and TEM shows that as the reaction temperature increases from 100 °C to 250 °C, the particles agglomerate. Selective area electron diffraction (SAED shows that the particles are crystalline in nature. The study shows that choosing suitable precursor and optimizing pressure and temperature; different meta-stable (ferroelectric phases of undoped BaTiO3 nanopowders can be stabilized by the sol-hydrothermal method.

  20. Particulate barium tracing of significant mesopelagic carbon remineralisation in the North Atlantic

    Science.gov (United States)

    Lemaitre, Nolwenn; Planquette, Hélène; Planchon, Frédéric; Sarthou, Géraldine; Jacquet, Stéphanie; García-Ibáñez, Maribel I.; Gourain, Arthur; Cheize, Marie; Monin, Laurence; André, Luc; Laha, Priya; Terryn, Herman; Dehairs, Frank

    2018-04-01

    The remineralisation of sinking particles by prokaryotic heterotrophic activity is important for controlling oceanic carbon sequestration. Here, we report mesopelagic particulate organic carbon (POC) remineralisation fluxes in the North Atlantic along the GEOTRACES-GA01 section (GEOVIDE cruise; May-June 2014) using the particulate biogenic barium (excess barium; Baxs) proxy. Important mesopelagic (100-1000 m) Baxs differences were observed along the transect depending on the intensity of past blooms, the phytoplankton community structure, and the physical forcing, including downwelling. The subpolar province was characterized by the highest mesopelagic Baxs content (up to 727 pmol L-1), which was attributed to an intense bloom averaging 6 mg chl a m-3 between January and June 2014 and by an intense 1500 m deep convection in the central Labrador Sea during the winter preceding the sampling. This downwelling could have promoted a deepening of the prokaryotic heterotrophic activity, increasing the Baxs content. In comparison, the temperate province, characterized by the lowest Baxs content (391 pmol L-1), was sampled during the bloom period and phytoplankton appear to be dominated by small and calcifying species, such as coccolithophorids. The Baxs content, related to oxygen consumption, was converted into a remineralisation flux using an updated relationship, proposed for the first time in the North Atlantic. The estimated fluxes were of the same order of magnitude as other fluxes obtained using independent methods (moored sediment traps, incubations) in the North Atlantic. Interestingly, in the subpolar and subtropical provinces, mesopelagic POC remineralisation fluxes (up to 13 and 4.6 mmol C m-2 d-1, respectively) were equalling and occasionally even exceeding upper-ocean POC export fluxes, deduced using the 234Th method. These results highlight the important impact of the mesopelagic remineralisation on the biological carbon pump of the studied area with a near

  1. Eliminating radium from uranium mill acid effluent with barium chloride-sodium carbonate precipitation

    International Nuclear Information System (INIS)

    Xiao Jiayuan

    1998-01-01

    The eliminating radium procedure, barium chloride-sodium carbonate-sand filtering, being used, radium can be eliminated to 3.7 x 10 -2 Bq/L order of magnitude from uranium mill acid effluents which contain 3.7 Bq/L Ra and pH 6∼9 when Ba 2+ is added by 3∼5 mg per litre, Na 2 CO 3 5mg. The radium elimination rate is more than 90%

  2. X-ray fluorescence analysis of strontium in environmental water by using barium carbonate coprecipitation method

    International Nuclear Information System (INIS)

    Nishioka, Hiroshi; Yoneda, Akio; Maeda, Yoshimichi; Azumi, Takatugu

    1986-01-01

    Determination of strontium in environmental water was studied by a coprecipitation method with barium carbonate and the subsequent X-ray fluorescence analysis. Fifty mg of barium ion and 1 g of sodium carbonate were added to sample water, which was then mixed for one hour by a magnetic stirrer. Precipitate was gathered onto a membrane filter paper to measure its XF intensity. The amount of strontium from 2 to 150 μg could be repeatedly determined by means of the calibration curve method, and the limit of detection was found to be 0.6 μg of strontium. A large amount of calcium and magnesium ions was found to interfere with the coprecipitation of strontium ion. However, this interference could be eliminated by using a small amount of sample water. Strontium in several environmental waters was determined by the above method. The results obtained from the calibration curve method and the standard addition method agreed with each other, and also agreed with those from the atomic absorption spectrometry. (author)

  3. Barium and Tc-poor S stars: Binary masqueraders among carbon stars

    OpenAIRE

    Jorissen, A.; Van Eck, S.

    1997-01-01

    The current understanding of the origin of barium and S stars is reviewed, based on new orbital elements and binary frequencies. The following questions are addressed: (i) Is binarity a necessary condition to produce a barium star? (ii) What is the mass transfer mode (wind accretion or RLOF?) responsible for their formation? (iii) Do barium stars form as dwarfs or as giants? (iv) Do barium stars evolve into Tc-poor S stars? (v) What is the relative frequency of Tc-rich and Tc-poor S stars?

  4. Cobalt phosphate-modified barium-doped tantalum nitride nanorod photoanode with 1.5% solar energy conversion efficiency

    KAUST Repository

    Li, Yanbo

    2013-10-03

    Spurred by the decreased availability of fossil fuels and global warming, the idea of converting solar energy into clean fuels has been widely recognized. Hydrogen produced by photoelectrochemical water splitting using sunlight could provide a carbon dioxide lean fuel as an alternative to fossil fuels. A major challenge in photoelectrochemical water splitting is to develop an efficient photoanode that can stably oxidize water into oxygen. Here we report an efficient and stable photoanode that couples an active barium-doped tantalum nitride nanostructure with a stable cobalt phosphate co-catalyst. The effect of barium doping on the photoelectrochemical activity of the photoanode is investigated. The photoanode yields a maximum solar energy conversion efficiency of 1.5%, which is more than three times higher than that of state-of-the-art single-photon photoanodes. Further, stoichiometric oxygen and hydrogen are stably produced on the photoanode and the counter electrode with Faraday efficiency of almost unity for 100 min. © 2013 Macmillan Publishers Limited. All rights reserved.

  5. Charge distributions of barium isotopes from muonic X-rays

    International Nuclear Information System (INIS)

    Shera, E.B.; Wohlfahrt, H.D.; Hoehn, M.V.; Tanaka, Y.

    1982-01-01

    The results of a muonic X-ray study of the charge radii of stable barium isotopes are presented and compared with optical isotope shifts. The isotope shifts Δ 2 > of a wide range of barium isotopes are found to be in good agreement with the droplet model and with IBA calculations. (orig.)

  6. Obtaining of a barium compound by combustion chemistry and their evaluation as Co adsorbent

    International Nuclear Information System (INIS)

    Rosas G, N.

    2008-01-01

    In this work, barium carbonate synthesized by chemical combustion method using a chemical precursor prepared by the combination of barium nitrate and urea as a fuel, with a 1:1 molar ratio in aqueous solution, the chemical precursor was heated to evaporate excess water, producing a homogeneous viscous liquid, that when heated to 900 centi grades for 5 minutes an exothermic reaction was produced very quickly and abruptly, forming a white powder final product, fine porous, little spongy, dry and crystalline ready to be used as material adsorbent. Additionally, the effect of water on the synthesis by chemical combustion was studied. Simultaneously, and with the purpose of comparing the advantages and disadvantages of the method by chemical combustion, barium carbonate was synthesized by precipitation method using barium nitrate salts and sodium carbonate. Synthesized barium carbonate, was characterized by X-ray diffraction, thermal gravimetric analysis, infrared spectrometry and scanning electron microscopy. We studied the adsorption capacity of Co present in aqueous solution by static tests on materials synthesized at room temperature using the neutron activation analysis. It was found that the synthesis by chemical combustion provides an interesting alternative compared to the synthesis by precipitation because it offers simplicity of synthesis and speed to have a good adsorbent material. It was found that the barium carbonate synthesized by the chemical combustion method using in their synthesis 1.0 ml of water, was the one who achieved the maximum adsorption capacity of 95.6% compared with the barium carbonate prepared by precipitation, which reached a capacity adsorption of 51.48%. (Author)

  7. Statistical properties of barium stars

    International Nuclear Information System (INIS)

    Hakkila, J.E.

    1986-01-01

    Barium stars are G- and K-giant stars with atmospheric excesses of s-process elements, and a broadband spectral depression in the blue portion of the spectrum. The strength of the λ4554 Ball line is used as a classification parameter known as the Barium Intensity. They have a mean absolute magnitude of 1.0 and a dispersion of 1.2 magnitudes (assuming a Gaussian distribution in absolute magnitude) as measured from secular and statistical parallaxes. These stars apparently belong to a young-disk population from analyses of both the solar reflex motion and their residual velocity distribution, which implies that they have an upper mass limit of around three solar masses. There is no apparent correlation of barium intensity with either luminosity or kinematic properties. The barium stars appear to be preferentially distributed in the direction of the local spiral arm, but show no preference to associate with or avoid the direction of the galactic center. They do not appear related to either the carbon or S-stars because of these tendencies and because of the stellar population to which each type of star belongs. The distribution in absolute magnitude combined with star count analyses implies that these stars are slightly less numerous than previously believed. Barium stars show infrared excesses that correlate with their barium intensities

  8. INFLUENCE OF BARIUM OXIDE ADDITIONS ON PORTLAND CLINKER

    Directory of Open Access Journals (Sweden)

    Anezka Zezulova

    2016-12-01

    Full Text Available Nowadays, nuclear power plants are widespread around the world and research is of great interest. Together with nuclear research, shielding of different types of radiation is an important current topic of research aiming at their safety. Portland cement has been an elementary building material for centuries. Since barium is very efficient in shielding different types of radiation, it can be assumed that the radiation shielding capability of cement can be improved by incorporation of barium. This work deals with the influence of barium oxide, added in the form of barium carbonate and sulphate, on the formation and properties of Portland clinker. The structure of burnt clinkers and the ratio of clinker phases were studied by polarizing microscopy and by X-ray diffraction. With increasing barium content, the alite-belite ratio decreases and the content of free lime gradually increases. Moreover, sulphates induce the growth of alite crystals. The ability of barium to be a part of the clinker minerals was observed by scanning electron microscopy. Belite and clinker melt contain the highest amount of barium, but aggregates of barium oxide are formed in the clinker melt. Furthermore, the rate of alite crystallization was studied under isothermal conditions.

  9. Photoluminescence properties and energy-transfer of thermal-stable Ce3+, Mn2+-codoped barium strontium lithium silicate red phosphors

    International Nuclear Information System (INIS)

    Zhang Xinguo; Gong Menglian

    2011-01-01

    Research highlights: → Excited by UV, strong red luminescence is observed from Ce 3+ , Mn 2+ -codoped barium strontium lithium silicate (BSLS), while violet-blue emission from Ce 3+ sole doped BSLS. → These results indicate the Mn 2+ -derived red emission is originated by an efficient Ce 3+ → Mn 2+ energy transfer. → The red emission becomes stronger with increased Sr content, and shows red-shift. → These phosphors demonstrate good thermal stability even in 180 o C, which is suitable for NUV LED application. - Abstract: A series of thermal-stable Ce 3+ , Mn 2+ -codoped barium strontium lithium silicate (BSLS) phosphors was synthesized by a high-temperature solid-state reaction. The XRD patterns of this phosphor seem to be a new phase that has not been reported before. BSLS:Ce 3+ , Mn 2+ showed two emission bands under 365 nm excitation: one observed at 421 nm was attributed to Ce 3+ emission, and the other found in red region was assigned to Mn 2+ emission through Ce 3+ -Mn 2+ efficient energy transfer. The Mn 2+ emission shifted red along with the replacement of barium by strontium, which was due to the change of crystal field. A composition-optimized phosphor, BSLS:0.10Ce 3+ , 0.05Mn 2+ (Ba = 65), exhibited strong and broad red-emitting and supreme thermal stability. The results suggest that this phosphor is suitable as a red component for NUV LED or high pressure Hg vapor (HPMV) lamp.

  10. Promotion of Water-mediated Carbon Removal by Nanostructured Barium Oxide/nickel Interfaces

    Energy Technology Data Exchange (ETDEWEB)

    L Yang; Y Choi; W Qin; H Chen; K Blinn; M Liu; P Liu; J Bai; T Tyson; M Liu

    2011-12-31

    The existing Ni-yttria-stabilized zirconia anodes in solid oxide fuel cells (SOFCs) perform poorly in carbon-containing fuels because of coking and deactivation at desired operating temperatures. Here we report a new anode with nanostructured barium oxide/nickel (BaO/Ni) interfaces for low-cost SOFCs, demonstrating high power density and stability in C{sub 3}H{sub 8}, CO and gasified carbon fuels at 750 C. Synchrotron-based X-ray analyses and microscopy reveal that nanosized BaO islands grow on the Ni surface, creating numerous nanostructured BaO/Ni interfaces that readily adsorb water and facilitate water-mediated carbon removal reactions. Density functional theory calculations predict that the dissociated OH from H2O on BaO reacts with C on Ni near the BaO/Ni interface to produce CO and H species, which are then electrochemically oxidized at the triple-phase boundaries of the anode. This anode offers potential for ushering in a new generation of SOFCs for efficient, low-emission conversion of readily available fuels to electricity.

  11. Formation of barium strontium titanate powder by solid state reaction using different calcination temperatures

    International Nuclear Information System (INIS)

    Teoh Wah Tzu; Ahmad Fauzi Mohd Noor; Zainal Arifin Ahmad

    2002-01-01

    The unique electrical properties of large permittivity in Barium Strontium Titanate have been widely used to make capacitors; it can be produced by solid state reaction. In this study, the mixture of Barium Carbonate, Strontium Carbonate and Titanium Dioxide was calcined at 500 degree C, 1000 degree C, 1100 degree C , 1150 degree C, 1200 degree C, 1250 degree C and 1300 degree C. The results of the phases change in each stage were investigated via X ay Diffraction. The results show that the formation of Barium Strontium Titanate started at 1100 degree C with the presence of other phases. The mixture is fully reacted to form Barium Strontium Titanate at 1150 degree C. Only Barium Strontium Titanate was formed as the calcination temperature was set higher. (Author)

  12. Complete sulphate removal from neutralised acidic mine drainage with barium carbonate

    CSIR Research Space (South Africa)

    Swanepoel, H

    2012-03-01

    Full Text Available -barium-calcium) Desalination process which uses barium salts to further reduce the sulphate concentration to acceptable levels with the added advantage that sulphate removal can be controlled due to the low solubility of BaSO4. This paper reports on the results...

  13. Novel thermally stable poly(vinyl chloride) composites for sulfate removal

    Energy Technology Data Exchange (ETDEWEB)

    Nadagouda, Mallikarjuna N., E-mail: Nadagouda.mallikarjuna@epa.gov [Water Supply and Water Resources Division, National Risk Management Research Laboratory U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive Cincinnati, Ohio 45268 (United States); Pressman, Jonathan; White, Colin; Speth, Thomas F.; McCurry, Daniel L. [Water Supply and Water Resources Division, National Risk Management Research Laboratory U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive Cincinnati, Ohio 45268 (United States)

    2011-04-15

    Graphical abstract: Barium carbonate and/or barium carbonate-loaded silica aero-gels dispersed polyvinyl chloride (PVC) composites were prepared by dissolving PVC in tetrahydrofuran (THF), dispersing BaCO{sub 3} and/or BaCO{sub 3}-loaded silica aero-gels, re-precipitating the PVC with water at room temperature. The PVC composites were then characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray mapping, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The obtained composites had better thermal properties than the control PVC. The composites were tested for sulfate removal and found to significantly reduce sulfate when compared with control PVC. - Abstract: BaCO{sub 3} dispersed PVC composites were prepared through a polymer re-precipitation method. The composites were tested for sulfate removal using rapid small scale column test (RSSCT) and found to significantly reduce sulfate concentration. The method was extended to synthesize barium carbonate-loaded silica aero-gels-polyvinyl chloride (PVC) polymer composites. The PVC composites were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray mapping, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The method has advantages over conventional sulfate precipitation (sulfate removal process) using BaCO{sub 3} wherein clogging of the filter can be avoided. The method is environmentally friendly and does not interfere with natural organic matter as the conventional resin does. Some of the composites were thermally more stable as compared with the pure PVC discussed in the literature.

  14. Novel thermally stable poly(vinyl chloride) composites for sulfate removal

    International Nuclear Information System (INIS)

    Nadagouda, Mallikarjuna N.; Pressman, Jonathan; White, Colin; Speth, Thomas F.; McCurry, Daniel L.

    2011-01-01

    Graphical abstract: Barium carbonate and/or barium carbonate-loaded silica aero-gels dispersed polyvinyl chloride (PVC) composites were prepared by dissolving PVC in tetrahydrofuran (THF), dispersing BaCO 3 and/or BaCO 3 -loaded silica aero-gels, re-precipitating the PVC with water at room temperature. The PVC composites were then characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray mapping, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The obtained composites had better thermal properties than the control PVC. The composites were tested for sulfate removal and found to significantly reduce sulfate when compared with control PVC. - Abstract: BaCO 3 dispersed PVC composites were prepared through a polymer re-precipitation method. The composites were tested for sulfate removal using rapid small scale column test (RSSCT) and found to significantly reduce sulfate concentration. The method was extended to synthesize barium carbonate-loaded silica aero-gels-polyvinyl chloride (PVC) polymer composites. The PVC composites were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray mapping, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The method has advantages over conventional sulfate precipitation (sulfate removal process) using BaCO 3 wherein clogging of the filter can be avoided. The method is environmentally friendly and does not interfere with natural organic matter as the conventional resin does. Some of the composites were thermally more stable as compared with the pure PVC discussed in the literature.

  15. BARIUM RECOVERY PROCESS

    Science.gov (United States)

    Blanco, R.E.

    1959-07-21

    A method of separating barium from nuclear fission products is described. In accordance with the invention, barium may be recovered from an acidic solution of neutron-irradiated fissionable material by carrying ihe barium cut of solution as a sulfate with lead as a carrier and then dissolving the barium-containing precipitate in an aqueous solution of an aliphatic diamine chelating reagent. The barium values together with certain other metallic values present in the diamine solution are then absorbed onto a cation exchange resin and the barium is selectively eluted from the resin bed with concentrated nitric acid.

  16. Nitrogen: Unraveling the Secret to Stable Carbon-Supported Pt-Alloy Electrocatalysts

    Science.gov (United States)

    2013-10-01

    release; distribution is unlimited. Nitrogen: unraveling the secret to stable carbon-supported Pt- alloy electrocatalysts The views, opinions and/or...Nitrogen: unraveling the secret to stable carbon-supported Pt-alloy electrocatalysts Report Title Nitrogen functionalities significantly improve...design and optimization of next generation high performance catalyst materials. Nitrogen: unraveling the secret to stable carbon-supported Pt-alloy

  17. Synthesis and characterization of nickel oxide doped barium strontium titanate ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, M. [Dept. of Electrical Engineering, Bengal Institute of Technology Kolkata (India); Mukherjee, S. [Dept. of Metallurgical Engineering, Jadavpur University, Kolkata (India); Maitra, S. [Govt. College of Engg. and Ceramic Technology, Kolkata (India)

    2012-01-15

    Barium strontium titanate (BST) ceramics (Ba{sub 0.6}Sr{sub 0.4})TiO{sub 3} were synthesized by solid state sintering using barium carbonate, strontium carbonate and rutile as the precursor materials. The samples were doped with nickel oxide in different proportions. Different phases present in the sintered samples were determined from X-ray diffraction investigation and the distribution of different phases in the microstructure was assessed from scanning electron microscopy study. It was observed that the dielectric properties of BST were modified significantly with nickel oxide doping. These ceramics held promise for applications in tuned circuits. (author)

  18. Effects of chemesthetic stimuli mixtures with barium on swallowing apnea duration.

    Science.gov (United States)

    Todd, J Tee; Butler, Susan G; Plonk, Drew P; Grace-Martin, Karen; Pelletier, Cathy A

    2012-10-01

    This study tested the hypotheses that swallowing apnea duration (SAD) will increase given barium versus water, chemesthetic stimuli (i.e., water barium, age (older > younger), and genetic taste differences (supertasters > nontasters). Prospective group design. University Medical Center. Eighty healthy women were identified as nontasters and supertasters, equally comprising two age groups: 18 to 35 years and 60+ years. The KayPentax Swallowing Signals Lab was used to acquire SAD via nasal cannula during individually randomized swallows of 5 mL barium, 2.7% w/v citric acid with barium, carbonation with barium, and 50:50 diluted ethanol with barium. Data were analyzed using path analysis, with the mediator of chemesthetic perception, adjusted for repeated measures. Significant main effects of age (P = .012) and chemesthetic stimuli (P = .014) were found, as well as a significant interaction between chemesthetic stimuli and age (P = .028). Older women had a significantly longer SAD than younger women. Post hoc analyses revealed that barium mixed with ethanol elicited a significantly longer SAD than other bolus conditions, regardless of age group. There were no significant differences in SAD between barium and water conditions, and no significant effect of chemesthetic perception (P > .05). Ethanol added to barium elicited longer SAD compared to plain barium, but not the other chemesthetic conditions. Older women had a longer SAD than younger women in all conditions. These findings may influence design of future studies examining effects of various stimuli on SAD. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

  19. Carbon dioxide sensor

    Science.gov (United States)

    Dutta, Prabir K [Worthington, OH; Lee, Inhee [Columbus, OH; Akbar, Sheikh A [Hilliard, OH

    2011-11-15

    The present invention generally relates to carbon dioxide (CO.sub.2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor that incorporates lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3). In another embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO.sub.2) sensors having lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3).

  20. Barium enema

    Science.gov (United States)

    ... series; Colorectal cancer - lower GI series; Colorectal cancer - barium enema; Crohn disease - lower GI series; Crohn disease - barium enema; Intestinal blockage - lower GI series; Intestinal blockage - ...

  1. Characterization of barium titanate powder doped with sodium and potassium ions by using Rietveld refining

    International Nuclear Information System (INIS)

    Andrade, M.C.; Assis, J.T.; Pereira, F.R.

    2009-01-01

    A solid-reaction synthesis of doped barium titanate was done by employing barium carbonates, sodium, potassium and titanium oxides with classic procedures. Rietveld refining of X ray diffraction data of perovskite samples with tetragonal symmetry was applying and show good agreement. Besides, the treatment performed from 600 deg C produces nanocrystals of barium titanate with average size of 33 nm. The presence of endothermic peaks related to BaTiO 3 formation at relatively low temperatures was determined by thermal analysis. A pseudo-Voigt Thompson-Cox-Hastings function was used to fit the standard samples of barium titanate. The Rietveld method has showed be efficient to detect the influences of temperature and doping on barium titanate microstructures. (author)

  2. Synthesis of barium mercaptides and application of antimony/barium mercaptides

    Institute of Scientific and Technical Information of China (English)

    瞿龙; 张露露; 舒万艮

    2001-01-01

    Mercaptoacetic acid, isooctyl thioglycolate and barium hydroxide used as start materials, barium bis (2-ethylhexyl thioglycolate) (Ba(2EHTG)2), barium thioglycolate (Ba(TG)) and barium bisthioglycolate (Ba(TG)2) were synthesized. Their optimum synthetic techniques were discussed, and some physicochemical data were reported. Infrared spectroscopy and elemental analysis methods were used to identify the structures. They were put into PVC plastic products together with antimony tris (2-ethylhexyl thioglycolate) (Sb(2EHTG)3) under the suitable compounding, and their heat stability to PVC was studied. It is shown that these barium mercaptides have remarkable synergisms with antimony mercaptides and the long-term stabilizing effect of organoantimony stabilizer can be effectively improved, reducing the amount of antimony compounds so as to avoid the decrease of its stabilizing effect.

  3. Determination of barium in natural waters by ICP-OES technique. Part II: Assessment of human exposure to barium in bottled mineral and spring waters produced in Poland.

    Science.gov (United States)

    Garboś, Sławomir; Swiecicka, Dorota

    2013-01-01

    A method of the classification of natural mineral and spring waters and maximum admissible concentration (MAC) levels of metals present in such types of waters are regulated by Commission Directive 2003/40/EC, Directive 2009/54/EC of the European Parliament and of the Council and Ordinance of Minister of Health of 30 March 2011 on the natural mineral waters, spring waters and potable waters. MAC of barium in natural mineral and spring waters was set at 1.0 mg/l, while World Health Organization determined the Ba guideline value in water intended for human consumption at the level of 0.7 mg/l. The aims of the study were: the determination of barium in natural mineral and spring waters (carbonated, non-carbonated and medium-carbonated waters) produced and bottled on the area of Poland, and assessment of human exposure to this metal presents in the above-mentioned types of waters. The study concerning barium determinations in 23 types of bottled natural mineral waters and 15 types of bottled spring waters (bought in Polish retail outlets) was conducted in 2010. The analyses were performed by validated method of determination of barium in water based on inductively coupled plasma optical emission spectrometry, using modern internal quality control scheme. Concentrations of barium determined in natural mineral and spring waters were in the ranges from 0.0136 mg/l to 1.12 mg/l and from 0.0044 mg/l to 0.43 mg/l, respectively. Only in the single case of natural mineral water the concentration of barium (1.12 mg/l), exceeded above-mentioned MAC for this metal, which is obligatory in Poland and the European Union - 1.0 mg/l. The long-term monitoring of barium concentration in another natural mineral water (2006 - 2010), in which incidental exceeding MAC was observed in 2006, was conducted. All measured barium concentrations in this water were lower than 1.0 mg/l and therefore, it is possible to state that the proper method of mixing waters taken from six independent

  4. SALT reveals the barium central star of the planetary nebula Hen 2-39

    Science.gov (United States)

    Miszalski, B.; Boffin, H. M. J.; Jones, D.; Karakas, A. I.; Köppen, J.; Tyndall, A. A.; Mohamed, S. S.; Rodríguez-Gil, P.; Santander-García, M.

    2013-12-01

    Classical barium stars are binary systems which consist of a late-type giant enriched in carbon and slow neutron capture (s-process) elements and an evolved white dwarf (WD) that is invisible at optical wavelengths. The youngest observed barium stars are surrounded by planetary nebulae (PNe), ejected soon after the wind accretion of polluted material when the WD was in its preceding asymptotic giant branch (AGB) phase. Such systems are rare but powerful laboratories for studying AGB nucleosynthesis as we can measure the chemical abundances of both the polluted star and the nebula ejected by the polluter. Here, we present evidence for a barium star in the PN Hen 2-39 (PN G283.8-04.2) as one of only a few known systems. The polluted giant is very similar to that found in WeBo 1 (PN G135.6+01.0). It is a cool (Teff = 4250 ± 150 K) giant enhanced in carbon ([C/H] = 0.42 ± 0.02 dex) and barium ([Ba/Fe] = 1.50 ± 0.25 dex). A spectral type of C-R3 C24 nominally places Hen 2-39 amongst the peculiar early R-type carbon stars; however, the barium enhancement and likely binary status mean that it is more likely to be a barium star with similar properties, rather than a true member of this class. An AGB star model of initial mass 1.8 M⊙ and a relatively large carbon pocket size can reproduce the observed abundances well, provided mass is transferred in a highly conservative way from the AGB star to the polluted star (e.g. wind Roche lobe overflow). It also shows signs of chromospheric activity and photometric variability with a possible rotation period of ˜5.5 d likely induced by wind accretion. The nebula exhibits an apparent ring morphology in keeping with the other PNe around barium stars (WeBo 1 and A 70) and shows a high degree of ionization implying the presence of an invisible hot pre-WD companion that will require confirmation with UV observations. In contrast to A 70, the nebular chemical abundance pattern is consistent with non-Type I PNe, in keeping with the

  5. Making of Magnet Barium Ferit Anisotropic

    International Nuclear Information System (INIS)

    Idayati, Novrita; Dedi

    2003-01-01

    Barium Hexa ferrite (BaFe 12 O 19 ) is ceramic and materials which usually used for making of permanent magnet. In this research Barium Hexa ferrite were made Anisotropic, and applied for loudspeaker, electro motors, dynamo, KWh metre, etc. this Magnet is commonly used due to its high Induction of Remanen (Br) and coercivity (high Hc). Besides it applies a more simple and easier process technology, cheaper raw material, and easy to find it, hence the magnetic component is much cheaper. Powder Metallurgy was used for the process technology, by reacting all materials in the powder (oxide), with a certain size distribution and a tight preparation step. The next step was mixing ferrite and Barium Carbonate (in the form of oxide), calcination, compaction, cantering and characterisation. The Anisotropic particle effects a high Induce Remanen (Br) and of koersifitas (high Hc). All the process steps will is determine physical and chemical characteristics of the magnet. The best Magnet characteristic of the magnet produced in this research is Induction of Remanen (Br) = 4,27 kg, Coercivity (Hc) = 1,745 kOe, Energy Product max (BHmaks) = 2,31 MGOe

  6. Barium isotopes in Allende meteorite - Evidence against an extinct superheavy element

    Science.gov (United States)

    Lewis, R. S.; Anders, E.; Shimamura, T.; Lugmair, G. W.

    1983-01-01

    Carbon and chromite fractions from the Allende meteorite that contain isotopically anomalous xenon-131 to xenon-136 (carbonaceous chondrite fission or CCF xenon) at up to 5 x 10 to the 11th atoms per gram show no detectable isotopic anomalies in barium-130 to barium-138. This rules out the possibility that the CCF xenon was formed by in situ fission of an extinct superheavy element. Apparently the CCF xenon and its carbonaceous carrier are relics from stellar nucleosynthesis.

  7. MR Colonography with fecal tagging: Barium vs. barium ferumoxsil

    DEFF Research Database (Denmark)

    Achiam, M.P.; Chabanova, E.; Logager, V.B.

    2008-01-01

    and Methods. Twenty patients referred to CC underwent dark lumen MRC prior to the colonoscopy. Two groups of patients received two different oral contrast agents (barium sulfate and barium sulfate/ferumoxsil) as a laxative-free fecal tagging prior to the MRC. After MRC, the contrast agent was rated...... qualitatively (with the standard method using contrast-to-wall ratio) and subjectively (using a visual analog scale [VAS]) by three different blinded observers. Results. Evaluated both qualitatively and subjectively, the tagging efficiency of barium sulfate/ferumoxsil was significantly better (P ... barium sulfate alone. The VAS method for evaluating the tagging efficiency of contrast agents showed a high correlation (observer 11, r = 0.91) to the standard method using contrast-to-wall ratio and also a high interclass correlation (observer 11 and III = 0.89/0.85). MRC found I of 22 (5%) polyps

  8. Isotopic exchange reaction between barium ion and tri barium phosphate

    International Nuclear Information System (INIS)

    Bilgin, G.B.; Cetin, I.

    1982-01-01

    Heterogeneous exchange reaction of tri barium phosphate in barium chloride solution has been studied using 133 Ba as a tracer. The results show that the exchange fraction increases as barium chloride concentration increases for different mole ratio of the exchange ion on the solid surface and in the solution. The phenomenon was studied with respect to the previous treatment of the precipitate leading to different crystal sizes and the effect of reaction time. (author)

  9. On barium oxide solubility in barium-containing chloride melts

    International Nuclear Information System (INIS)

    Nikolaeva, Elena V.; Zakiryanova, Irina D.; Bovet, Andrey L.; Korzun, Iraida V.

    2016-01-01

    Oxide solubility in chloride melts depends on temperature and composition of molten solvent. The solubility of barium oxide in the solvents with barium chloride content is essentially higher than that in molten alkali chlorides. Spectral data demonstrate the existence of oxychloride ionic groupings in such melts. This work presents the results of the BaO solubility in two molten BaCl 2 -NaCl systems with different barium chloride content. The received data together with earlier published results revealed the main regularities of BaO solubility in molten BaO-BaCl 2 -MCl systems.

  10. Patient dose variation investigated in four Irish hospitals for barium meal and barium enema examinations

    International Nuclear Information System (INIS)

    Carroll, E.; Brennan, P.C.

    2001-01-01

    Four hospitals have been studied, intra- and inter-hospital variations examined and the mean DAP values recorded for barium enemas and barium meals. Mean DAP values for barium meals and barium enemas at 11.4 Gy.cm 2 and 20.1 Gy.cm 2 respectively have been shown. Differences between individual examinations for barium meals varied by up to a factor of 185 and for barium enemas, up to a factor of 19, with hospital means for barium meal and enema examinations each differing by up to a factor of 3. The data provided by this study have suggested that large variations in patient dose do exist in Ireland for barium meal and barium enema examinations. Fluoroscopy time was shown to be a major contributor to the variations reported, with number of images playing a minor role. Results have demonstrated the need for standardisation of technique throughout the country for these examinations. (author)

  11. Reducing conditions on barium absorption in rice plants cultured in BaSO4-enriched soil doi: 10.4025/actasciagron.v36i1.17539

    Directory of Open Access Journals (Sweden)

    Marcio Osvaldo Lima Magalhães

    2014-01-01

    Full Text Available To evaluate the possible solubilization of barium sulfate in soils under reducing conditions and its effects on barium bioavailability, an Oryza sativa pot trial was established. Increasing barium doses and two redox potential conditions were evaluated. The geochemical fractionation data demonstrated that reducing conditions led to an increase in the levels of more labile forms of barium and a reduction in more stable forms. Furthermore, higher doses of barium were found to have a negative impact on grain production. The highest levels of barium accumulation in the leaves, roots, and grains were observed with the highest barium dose under reducing conditions. These results demonstrate that reducing conditions increased barium bioavailability and absorption by rice plants.

  12. Stable-carbon isotope variability in tree foliage and wood

    International Nuclear Information System (INIS)

    Leavitt, S.W.; Long, A.

    1986-01-01

    This study documents variation of stable-carbon isotope ratios ( 13 C/ 12 C) in trees of genera Juniperus and Pinus under field conditions. Results are from cellulose analysis on leaves, twigs, and wood from a number of localities in the southwestern US. Substantial variability, typically 1-3%, exists among leaves, within wood (radially, vertically, circumferentially), and between individuals at a site. These results may help guide sampling in tracer-type studies with stable-carbon isotope ratios and aid in the interpretation of isotopic results from such studies

  13. Biosynthetic effects on the stable carbon isotopic compositions of agal lipids: Implications for deciphering the carbon isotopic biomarker record

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Schouten, S.; Klein Breteler, W.C.M.; Blokker, P.; Schogt, N.; Rijpstra, W.I.C.; Grice, K.; Baas, M.

    1998-01-01

    Thirteen species of algae covering an extensive range of classes were cultured and stable carbon isotopic compositions of their lipids were analysed in order to assess carbon isotopic fractionation effects during their biosynthesis. The fatty acids were found to have similar stable carbon isotopic

  14. Inconceivable Hypokalemia: A Case Report of Acute Severe Barium Chloride Poisoning

    Directory of Open Access Journals (Sweden)

    Haibo Tao

    2016-01-01

    Full Text Available Barium is a heavy divalent alkaline earth metal that has been known as a muscle poison. Barium can cause human toxicity, which may lead to significant hypokalemia and have serious consequences. This paper reports a case of unprecedented barium intoxication in which the patient, who suffered from depression, swallowed at least 3.0 g barium chloride to commit suicide. On admission, the patient presented with nausea, vomiting, stomach burning feeling, dizziness, and weakness. Emergency biochemical testing showed that the patient was suffering from severe hypokalemia (K+ 1.7 mmol/L. His electrocardiogram (ECG prompted atrioventricular blocking, ventricular tachycardia, prolongation of PR interval, ST segment depression with U waves, and T wave inversion. Intravenous potassium supplements were given immediately to correct hypokalemia and regular monitoring of vital signs and fluid balance was arranged. After all-out rescue of our hospital personnel, the condition of the patient is currently stable and he is gradually recovering. This case exemplifies the weaknesses of the management of toxic substances and the lack of mental health education for young people. We hope to get more attention for the supervision of toxic substances and the healthy development of young people.

  15. Lithium in the barium stars

    International Nuclear Information System (INIS)

    Pinsonneault, M.H.; Sneden, C.

    1984-01-01

    New high-resolution spectra of the lithium resonance doublet have provided lithium abundances or upper limits for 26 classical and mild barium stars. The lithium lines always are present in the classical barium stars. Lithium abundances in these stars obey a trend with stellar masses consistent with that previously derived for ordinary K giants. This supports the notion that classical barium stars are post-core-He-flash or core-He-burning stars. Lithium contents in the mild barium stars, however, often are much smaller than those of the classical barium stars sometimes only upper limits may be determined. The cause for this difference is not easily understood, but may be related to more extensive mass loss by the mild barium stars. 45 references

  16. Barium enema (image)

    Science.gov (United States)

    A barium enema is performed to examine the walls of the colon. During the procedure, a well lubricated enema tube is inserted gently into the rectum. The barium, a radiopaque (shows up on X-ray) contrast ...

  17. Barium light source method and apparatus

    Science.gov (United States)

    Curry, John J. (Inventor); MacDonagh-Dumler, Jeffrey (Inventor); Anderson, Heidi M. (Inventor); Lawler, James E. (Inventor)

    2002-01-01

    Visible light emission is obtained from a plasma containing elemental barium including neutral barium atoms and barium ion species. Neutral barium provides a strong green light emission in the center of the visible spectrum with a highly efficient conversion of electrical energy into visible light. By the selective excitation of barium ionic species, emission of visible light at longer and shorter wavelengths can be obtained simultaneously with the green emission from neutral barium, effectively providing light that is visually perceived as white. A discharge vessel contains the elemental barium and a buffer gas fill therein, and a discharge inducer is utilized to induce a desired discharge temperature and barium vapor pressure therein to produce from the barium vapor a visible light emission. The discharge can be induced utilizing a glow discharge between electrodes in the discharge vessel as well as by inductively or capacitively coupling RF energy into the plasma within the discharge vessel.

  18. Barium granuloma of the rectum: case report

    International Nuclear Information System (INIS)

    Kim, Dae Jin; Kim, Se Hyung; Jeoung, Ah Young; Lee, Kyoung Ho; Choi, Byung Ihn; Han, Joon Koo

    2003-01-01

    Barium granulomas usually occur after barium enema within 8 cm of the anal verge probably due to minute laceration of rectal wall by enema tip and extravasation of barium during barium enema. We report a case of barium granuloma of rectum in a 47-year-old man, who did not have history of barium enema. In rare instance, barium granuloma can occur without a history of barium enema and careful interpretation of radiologic image is essential to make a correct diagnosis

  19. Barium toxicosis in a dog.

    Science.gov (United States)

    Adam, Fiona H; Noble, Peter J M; Swift, Simon T; Higgins, Brent M; Sieniawska, Christine E

    2010-09-01

    A 2-year-old 14.9-kg (32.8-lb) neutered female Shetland Sheepdog was admitted to the University of Liverpool Small Animal Teaching Hospital for evaluation of acute collapse. At admission, the dog was tachypneic and had reduced limb reflexes and muscle tone in all limbs consistent with diffuse lower motor neuron dysfunction. The dog was severely hypokalemic (1.7 mEq/L; reference range, 3.5 to 5.8 mEq/L). Clinical status of the dog deteriorated; there was muscle twitching, flaccid paralysis, and respiratory failure, which was considered a result of respiratory muscle weakness. Ventricular arrhythmias and severe acidemia (pH, 7.18; reference range, 7.35 to 7.45) developed. Intoxication was suspected, and plasma and urine samples submitted for barium analysis had barium concentrations comparable with those reported in humans with barium toxicosis. Analysis of barium concentrations in 5 control dogs supported the diagnosis of barium toxicosis in the dog. Fluids and potassium supplementation were administered IV. The dog recovered rapidly. Electrolyte concentrations measured after recovery were consistently unremarkable. Quantification of plasma barium concentration 56 days after the presumed episode of intoxication revealed a large decrease; however, the plasma barium concentration remained elevated, compared with that in control dogs. To our knowledge, this case represented the first description of barium toxicosis in the veterinary literature. Barium toxicosis can cause life-threatening hypokalemia; however, prompt supportive treatment can yield excellent outcomes. Barium toxicosis is a rare but important differential diagnosis in animals with hypokalemia and appropriate clinical signs.

  20. Barium uranyl diphosphonates

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Anna-Gay D., E-mail: nelsoa@umich.edu [Department of Civil Engineering and Geological Sciences and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States); Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States); Alekseev, Evgeny V. [Institute of Energy and Climate Research (IEK-6), Forschungszentrum Juelich Wilhelm-Johnen-Strasse, Juelich 52428 (Germany); Ewing, Rodney C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109-1005 (United States); Albrecht-Schmitt, Thomas E. [Department of Civil Engineering and Geological Sciences and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556 (United States)

    2012-08-15

    Three Ba{sup 2+}/UO{sub 2}{sup 2+} methylenediphosphonates have been prepared from mild hydrothermal treatment of uranium trioxide, methylendiphosphonic acid (C1P2) with barium hydroxide octahydrate, barium iodate monohydrate, and small aliquots of HF at 200 Degree-Sign C. These compounds, Ba[UO{sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{center_dot}1.4H{sub 2}O (Ba-1), Ba{sub 3}[(UO{sub 2}){sub 4}(CH{sub 2}(PO{sub 3}){sub 2}){sub 2}F{sub 6}]{center_dot}6H{sub 2}O (Ba-2), and Ba{sub 2}[(UO{sub 2}){sub 2}(CH{sub 2}(PO{sub 3}){sub 2})F{sub 4}]{center_dot}5.75H{sub 2}O (Ba-3) all adopt layered structures based upon linear uranyl groups and disphosphonate molecules. Ba-2 and Ba-3 are similar in that they both have UO{sub 5}F{sub 2} pentagonal bipyramids that are bridged and chelated by the diphosphonate moiety into a two-dimensional zigzag anionic sheet (Ba-2) and a one-dimensional ribbon anionic chain (Ba-3). Ba-1, has a single crystallographically unique uranium metal center where the C1P2 ligand solely bridges to form [UO{sub 2}[CH{sub 2}(PO{sub 3}){sub 2}]{sup 2-} sheets. The interlayer space of the structures is occupied by Ba{sup 2+}, which, along with the fluoride ion, mediates the structure formed and maintains overall charge balance. - Graphical abstract: Illustration of the stacking of the layers in Ba{sub 3}[(UO{sub 2}){sub 4}(CH{sub 2}(PO{sub 3}){sub 2}){sub 2})F{sub 6}]{center_dot}6H{sub 2}O viewed along the c-axis. The structure is constructed from UO{sub 7} pentagonal bipyramidal units, U(1)O{sub 7}=gray, U(2)O{sub 7}=yellow, barium=blue, phosphorus=magenta, fluorine=green, oxygen=red, carbon=black, and hydrogen=light peach. Highlights: Black-Right-Pointing-Pointer The polymerization of the UO{sub 2}{sup 2+} sites to form uranyl dimers leads to structural variations in compounds. Black-Right-Pointing-Pointer Barium cations stitch uranyl diphosphonate anionic layers together, and help mediate structure formation. Black-Right-Pointing-Pointer HF acts as both a

  1. Obtaining of a barium compound by combustion chemistry and their evaluation as Co adsorbent; Obtencion de un compuesto de bario por combustion quimica y su evaluacion como adsorbente de Co

    Energy Technology Data Exchange (ETDEWEB)

    Rosas G, N [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2008-07-01

    In this work, barium carbonate synthesized by chemical combustion method using a chemical precursor prepared by the combination of barium nitrate and urea as a fuel, with a 1:1 molar ratio in aqueous solution, the chemical precursor was heated to evaporate excess water, producing a homogeneous viscous liquid, that when heated to 900 centi grades for 5 minutes an exothermic reaction was produced very quickly and abruptly, forming a white powder final product, fine porous, little spongy, dry and crystalline ready to be used as material adsorbent. Additionally, the effect of water on the synthesis by chemical combustion was studied. Simultaneously, and with the purpose of comparing the advantages and disadvantages of the method by chemical combustion, barium carbonate was synthesized by precipitation method using barium nitrate salts and sodium carbonate. Synthesized barium carbonate, was characterized by X-ray diffraction, thermal gravimetric analysis, infrared spectrometry and scanning electron microscopy. We studied the adsorption capacity of Co present in aqueous solution by static tests on materials synthesized at room temperature using the neutron activation analysis. It was found that the synthesis by chemical combustion provides an interesting alternative compared to the synthesis by precipitation because it offers simplicity of synthesis and speed to have a good adsorbent material. It was found that the barium carbonate synthesized by the chemical combustion method using in their synthesis 1.0 ml of water, was the one who achieved the maximum adsorption capacity of 95.6% compared with the barium carbonate prepared by precipitation, which reached a capacity adsorption of 51.48%. (Author)

  2. Lower GI Series (Barium Enema)

    Science.gov (United States)

    ... uses x-rays and a chalky liquid called barium to view your large intestine . The barium will make your large intestine more visible on ... single-contrast lower GI series, which uses only barium a double-contrast or air-contrast lower GI ...

  3. Monitoring in situ biodegradation of hydrocarbons by using stable carbon isotopes

    International Nuclear Information System (INIS)

    Aggarwal, P.K.; Hinchee, R.E.

    1991-01-01

    Spilled or leaked nonhalogenated petroleum hydrocarbons in the soil can generally be metabolized by indigenous, aerobic bacteria. In situ biological degradation of hydrocarbons may be accelerated by supplying inorganic nutrients and/or oxygen. Approaches to monitoring and verifying enhanced in situ biodegradation have included measurements of changes over time in the (a) concentration of hydrocarbons, (b) temperature, (c) number of hydrocarbon-degrading microorganisms, (d) ratio of fast-degrading hydrocarbons (e.g., pristanes or phytanes), and (e) metabolic intermediates. Measurements of oxygen consumption over time and elevated carbon dioxide concentrations in soil gas also have been used as indicators of hydrocarbon degradation. An alternative approach that may help substantiate biodegradation is to measure stable carbon isotope ratios in soil gas CO 2 . Stable carbon isotope ratio analysis is inexpensive and commercially available at many laboratories. Carbon dioxide produced by hydrocarbon degradation may be distinguished from that produced by other processes based on the carbon isotopic compositions characteristic of the source material and/or fractionation accompanying microbial metabolism. Here the authors demonstrate the applicability of the stable isotope technique for monitoring enhanced. aerobic biodegradation of hydrocarbons using data from three locations in the United States

  4. Barium Depletion in Hollow Cathode Emitters

    Science.gov (United States)

    Polk, James E.; Capece, Angela M.; Mikellides, Ioannis G.; Katz, Ira

    2009-01-01

    The effect of tungsten erosion, transport and redeposition on the operation of dispenser hollow cathodes was investigated in detailed examinations of the discharge cathode inserts from an 8200 hour and a 30,352 hour ion engine wear test. Erosion and subsequent re-deposition of tungsten in the electron emission zone at the downstream end of the insert reduces the porosity of the tungsten matrix, preventing the ow of barium from the interior. This inhibits the interfacial reactions of the barium-calcium-aluminate impregnant with the tungsten in the pores. A numerical model of barium transport in the internal xenon discharge plasma shows that the barium required to reduce the work function in the emission zone can be supplied from upstream through the gas phase. Barium that flows out of the pores of the tungsten insert is rapidly ionized in the xenon discharge and pushed back to the emitter surface by the electric field and drag from the xenon ion flow. This barium ion flux is sufficient to maintain a barium surface coverage at the downstream end greater than 0.6, even if local barium production at that point is inhibited by tungsten deposits. The model also shows that the neutral barium pressure exceeds the equilibrium vapor pressure of the impregnant decomposition reaction over much of the insert length, so the reactions are suppressed. Only a small region upstream of the zone blocked by tungsten deposits is active and supplies the required barium. These results indicate that hollow cathode failure models based on barium depletion rates in vacuum dispenser cathodes are very conservative.

  5. Carbon-14 waste management

    International Nuclear Information System (INIS)

    Bush, R.P.

    1984-01-01

    As part of their research programme on Radioactive Waste Management, the Commission of the European Communities has provided financial support for a detailed study of wastes containing 14 C and the options for their management. The main results of this study are outlined. Carbon-14 is formed by neutron activation reactions in core materials and is therefore present in a variety of waste streams both at reactors and at reprocessing plants. Data on the production and release of 14 C from various reactor systems are presented. A possible management strategy for 14 C might be reduction of 14 N impurity levels in core materials, but only reductions of about a factor of five in arisings could be achieved in this way. The key problem in 14 C management is its retention in off-gas streams, particularly in the dissolver off-gas stream at reprocessing plants. In this stream the nuclide is present as carbon dioxide and is extensively isotopically diluted by the carbon dioxide content of the air. Processes for trapping 14 C from these off-gases must be integrated with the other processes in the overall off-gas treatment system, and should provide for conversion to a stable solid compound of carbon, suitable for subsequent immobilization and disposal. Three trapping processes that convert carbon dioxide into insoluble carbonates can be identified: the double alkali (NaOH/Ca(OH) 2 ) process, the direct calcium hydroxide slurry process, and the barium ocathydrate gas/solid process. Calcium or barium carbonates, produced in the above processes, could probably be incorporated into satisfactory immobilized waste forms. However, the stability of such waste forms to prolonged irradiation and to leaching remains to be investigated. (author)

  6. Tracing organic matter sources of estuarine tidal flat nematodes with stable carbon isotopes

    NARCIS (Netherlands)

    Moens, T.; Luyten, C.; Middelburg, J.J.; Herman, P.M.J.; Vincx, M.

    2002-01-01

    The present study explores the use of stable carbon isotopes to trace organic matter sources of intertidal nematodes in the Schelde estuary (SW Netherlands). Stable carbon isotope signatures of nematodes from a saltmarsh and 4 tidal flat stations were determined in spring and winter situations, and

  7. Barium diffusion in metallo-organic solution deposited barrier layers and Y1Ba2Cu3O7-x films

    International Nuclear Information System (INIS)

    Lipeles, R.A.; Leung, M.S.; Thiede, D.A.

    1990-01-01

    This paper reports on barium silicate and barium aluminate films that were studied for use as chemical reaction and diffusion barrier layers for Y 1 Ba 2 Cu 3 O 7-x (YBC) deposited on sapphire and fused silica substrates by the sol-gel technique. Depth profiling by secondary ion mass spectrometry (SIMS) was used to characterize the abruptness of the interfaces between the barrier layer and the YBC film as well as the barrier layer and the substrate. The authors found that barium aluminate films reacted with fused silica substrates forming a coarse-grained barium silicate phase. Barium silicate, BaSiO 3 , also reacted with silica substrates forming a broad, amorphous reaction zone containing some BaSi 2 O 5 . Although barium silicate and barium aluminate deposited on sapphire formed a BaAl 12 O 19 phase, they provided a barrier to barium diffusion from sol-gel deposited YBC. Crystalline barium aluminate grown on c-cut sapphire was the most effective barrier layer for the growth of YBC films; compositionally uniform YBC films were made similar to that grown on strontium titanate substrates. These data show that chemically stable, crystalline films are more effective barrier layers than amorphous films

  8. Methodologies for extraction of dissolved inorganic carbon for stable carbon isotope studies : evaluation and alternatives

    Science.gov (United States)

    Hassan, Afifa Afifi

    1982-01-01

    The gas evolution and the strontium carbonate precipitation techniques to extract dissolved inorganic carbon (DIC) for stable carbon isotope analysis were investigated. Theoretical considerations, involving thermodynamic calculations and computer simulation pointed out several possible sources of error in delta carbon-13 measurements of the DIC and demonstrated the need for experimental evaluation of the magnitude of the error. An alternative analytical technique, equilibration with out-gassed vapor phase, is proposed. The experimental studies revealed that delta carbon-13 of the DIC extracted from a 0.01 molar NaHC03 solution by both techniques agreed within 0.1 per mil with the delta carbon-13 of the DIC extracted by the precipitation technique, and an increase of only 0.27 per mil in that extracted by the gas evolution technique. The efficiency of extraction of DIC decreased with sulfate concentration in the precipitation technique but was independent of sulfate concentration in the gas evolution technique. Both the precipitation and gas evolution technique were found to be satisfactory for extraction of DIC from different kinds of natural water for stable carbon isotope analysis, provided appropriate precautions are observed in handling the samples. For example, it was found that diffusion of atmospheric carbon dioxide does alter the delta carbon-13 of the samples contained in polyethylene bottles; filtration and drying in the air change the delta carbon-13 of the samples contained in polyethylene bottles; filtration and drying in the air change the delta carbon-13 of the precipitation technique; hot manganese dioxide purification changes the delta carbon-13 of carbon dioxide. (USGS)

  9. Microwave-hydrothermal synthesis of barium strontium titanate nanoparticles

    International Nuclear Information System (INIS)

    Simoes, A.Z.; Moura, F.; Onofre, T.B.; Ramirez, M.A.; Varela, J.A.; Longo, E.

    2010-01-01

    Research highlights: → Barium strontium titanate nanoparticles were obtained by the Hydrothemal microwave technique (HTMW) → This is a genuine technique to obtain nanoparticles at low temperature and short times → Barium strontium titanate free of carbonates with tetragonal structure was grown at 130 o C. - Abstract: Hydrothermal-microwave method (HTMW) was used to synthesize crystalline barium strontium titanate (Ba 0.8 Sr 0.2 TiO 3 ) nanoparticles (BST) in the temperature range of 100-130 o C. The crystallization of BST with tetragonal structure was reached at all the synthesis temperatures along with the formation of BaCO 3 as a minor impurity at lower syntheses temperatures. Typical FT-IR spectra for tetragonal (BST) nanoparticles presented well defined bands, indicating a substantial short-range order in the system. TG-DTA analyses confirmed the presence of lattice OH- groups, commonly found in materials obtained by HTMW process. FE/SEM revealed that lower syntheses temperatures led to a morphology that consisted of uniform grains while higher syntheses temperature consisted of big grains isolated and embedded in a matrix of small grains. TEM has shown BST nanoparticles with diameters between 40 and 80 nm. These results show that the HTMW synthesis route is rapid, cost effective, and could serve as an alternative to obtain BST nanoparticles.

  10. Stable and radioactive carbon in Indian soils: implications to soil carbon dynamics

    International Nuclear Information System (INIS)

    Laskar, A.H.; Yadava, M.G.; Ramesh, R.

    2011-01-01

    Radiocarbon is a very useful tool to study soil carbon dynamic. The mean residence time of SOC in Indian soils is about a century at the top 0-15 cm, increases linearly to reach values ranging from 2000 to 4000 yrs at a depth of 100 cm. It mainly depends on the clay content indicating that the clay is the main governing factor for SOC stabilization. Stable carbon and oxygen isotopes in soil carbonates and SOC are good proxies for paleoclimate and paleovegetation reconstruction. The present day sub-humid climate in the lower Narmada valley has been established prior to ∼ 3 ka. Two comparatively arid phases around 2.1 and 1.3 ka are recorded by oxygen isotopes of soil carbonates; consistent with other proxy records showing its regional significance

  11. Stable carbon isotope biogeochemistry of lakes along a trophic gradient

    NARCIS (Netherlands)

    de Kluijver, A.; Schoon, P.L.; Downing, J.A.; Schouten, S.; Middelburg, J.J.

    2014-01-01

    The stable carbon (C) isotope variability of dissolved inorganic and organic C (DIC and DOC), particulate organic carbon (POC), glucose and polar-lipid derived fatty acids (PLFAs) was studied in a survey of 22 North American oligotrophic to eutrophic lakes. The d13C of different PLFAs were used as

  12. Theoretical study of phonon dispersion, elastic, mechanical and thermodynamic properties of barium chalcogenides

    Science.gov (United States)

    Musari, A. A.; Orukombo, S. A.

    2018-03-01

    Barium chalcogenides are known for their high-technological importance and great scientific interest. Detailed studies of their elastic, mechanical, dynamical and thermodynamic properties were carried out using density functional theory and plane-wave pseudo potential method within the generalized gradient approximation. The optimized lattice constants were in good agreement when compared with experimental data. The independent elastic constants, calculated from a linear fit of the computed stress-strain function, were used to determine the Young’s modulus (E), bulk modulus (B), shear modulus (G), Poisson’s ratio (σ) and Zener’s anisotropy factor (A). Also, the Debye temperature and sound velocities for barium chalcogenides were estimated from the three independent elastic constants. The calculations of phonon dispersion showed that there are no negative frequencies throughout the Brillouin zone. Hence barium chalcogenides have dynamically stable NaCl-type crystal structure. Finally, their thermodynamic properties were calculated in the temperature range of 0-1000 K and their constant-volume specific heat capacities at room-temperature were reported.

  13. Barium and iron abundances in red giants

    International Nuclear Information System (INIS)

    Fernandez-Villacanas, J.L.; Rego, M.; Cornide, M.

    1990-01-01

    An intermediate-dispersion abundance analysis has been carried out on a sample of 21 barium and 14 comparison stars. The excess of barium over iron has been used as the most representative indicator of peculiarity. These excesses are higher in the peculiar stars than in the nonpeculiar stars. Particularly interesting is the case of HD 67447, included in the comparison stars, with an excess Ba/Fe abundance = 1.61, probably a new barium star. A trend indicating a possible anticorrelation between barium overabundance and metallicity favors the suggestion that the barium strong group is older than the barium weak one. 36 refs

  14. A new double contrast barium enema

    International Nuclear Information System (INIS)

    Park, Jun Sang; Cho, Won Sik; Lee, Sung Woo; Lee, Mun Gyu; Jeon, Jeong Dong; Jaun, Woo Ki; Han, Chung Yul

    1987-01-01

    A new technic of the barium enema was proposed for the better colonic double contrast study with the average 204ml of 50w/v% barium, applied to 109 serial patients. The barium was introduced to sigmoid colon, and then pushed to a mid transverse colon by the air insufflation through an enema syringe, a new device. An advance to cecum is accomplished by the air insufflation and/or the position change of the patient. The barium transfer method was developed for the best spot film exposure, through colon, by the position change of the patient, the tilting of the x-ray table and the air insufflation with the enema syringe. The mean angle of the x-ray table tilted was -10 .deg. at the beginning the barium enema till the barium sent past the splenic flexure, -15 . deg. for the best lateral view of rectum and -18 .deg. for the bet prone PA view of rectosigmoid colon. This was a simple, better and economic double contrast barium enema for the cooperative patients

  15. Discrimination factors of carbon and nitrogen stable isotopes in meerkat feces

    Directory of Open Access Journals (Sweden)

    Shaena Montanari

    2017-06-01

    Full Text Available Stable isotope analysis of feces can provide a non-invasive method for tracking the dietary habits of nearly any mammalian species. While fecal samples are often collected for macroscopic and genetic study, stable isotope analysis can also be applied to expand the knowledge of species-specific dietary ecology. It is somewhat unclear how digestion changes the isotope ratios of animals’ diets, so more controlled diet studies are needed. To date, most diet-to-feces controlled stable isotope experiments have been performed on herbivores, so in this study I analyzed the carbon and nitrogen stable isotope ratios in the diet and feces of the meerkat (Suricata suricatta, a small omnivorous mammal. The carbon trophic discrimination factor between diet and feces (Δ13Cfeces is calculated to be 0.1 ± 1.5‰, which is not significantly different from zero, and in turn, not different than the dietary input. On the other hand, the nitrogen trophic discrimination factor (Δ15Nfeces is 1.5 ± 1.1‰, which is significantly different from zero, meaning it is different than the average dietary input. Based on data generated in this experiment and a review of the published literature, carbon isotopes of feces characterize diet, while nitrogen isotope ratios of feces are consistently higher than dietary inputs, meaning a discrimination factor needs to be taken into account. The carbon and nitrogen stable isotope values of feces are an excellent snapshot of diet that can be used in concert with other analytical methods to better understand ecology, diets, and habitat use of mammals.

  16. Radioactive Barium Ion Trap Based on Metal-Organic Framework for Efficient and Irreversible Removal of Barium from Nuclear Wastewater.

    Science.gov (United States)

    Peng, Yaguang; Huang, Hongliang; Liu, Dahuan; Zhong, Chongli

    2016-04-06

    Highly efficient and irreversible capture of radioactive barium from aqueous media remains a serious task for nuclear waste disposal and environmental protection. To address this task, here we propose a concept of barium ion trap based on metal-organic framework (MOF) with a strong barium-chelating group (sulfate and sulfonic acid group) in the pore structures of MOFs. The functionalized MOF-based ion traps can remove >90% of the barium within the first 5 min, and the removal efficiency reaches 99% after equilibrium. Remarkably, the sulfate-group-functionalized ion trap demonstrates a high barium uptake capacity of 131.1 mg g(-1), which surpasses most of the reported sorbents and can selectively capture barium from nuclear wastewater, whereas the sulfonic-acid-group-functionalized ion trap exhibits ultrafast kinetics with a kinetic rate constant k2 of 27.77 g mg(-1) min(-1), which is 1-3 orders of magnitude higher than existing sorbents. Both of the two MOF-based ion traps can capture barium irreversibly. Our work proposes a new strategy to design barium adsorbent materials and provides a new perspective for removing radioactive barium and other radionuclides from nuclear wastewater for environment remediation. Besides, the concrete mechanisms of barium-sorbent interactions are also demonstrated in this contribution.

  17. An experimental study on barium peritonitis in rats

    International Nuclear Information System (INIS)

    Kang, Heung Sik; Han, Man Chung; Kim, Chu Wan

    1985-01-01

    Barium sulfate is universally used contrast media in gastrointestinal roentgenology, and spillage of barium into peritoneal cavity can occur. The references on effect of barium sulfate in the peritoneal cavity have been scattered and the results are varied. In 80 rats, body weight of 130 gm to 150 gm, sterile pure barium, sterile commercial barium, intestinal content, and mixed pure barium and intestinal content were experimentally injected into the peritoneal cavity. Consecutive weekly laparotomy and microscopic examination were done for 4 weeks. The results are as followings: 1. Mind inflammatory reaction and mild adhesion after sterile pure barium injection. 2. Mild inflammatory reaction and moderate adhesion after sterile commercial barium injection. 3. Acute peritonitis and abscess formation after intestinal content injection. 4. High mortality due to severe acute peritonitis, and severe adhesion in survivors after injection of both pure barium and intestinal content.

  18. Attainment of barium hexaferrite nanoparticles by a Pechini Method

    International Nuclear Information System (INIS)

    Galvao, S.B.; Timoteo, Jr.J.F.; Melo, G.M.; Souto, K.K.O.; Florioto, N.T.; Paskocimas, C.A.

    2009-01-01

    The barium hexaferrites (BaFe 12 O 19 ) are used as a compound of materials applied in electronic devices, as medical devices, satellites, dada servers systems, wireless systems and others. The general properties are strongly related to the microstructure and morphology, and the particles size decrease results in advantages to the majority applications, mainly the high-tech thumbnail devices. These magnetic ceramic materials, with perovskite structure, are traditionally prepared my conventional oxide mixture synthesis. In this work was studied the nanoparticle synthesis of BaFe 12 O 19 by the precursors polymeric method (Pechini), using as precursors the barium carbonate and the iron nitrate, under different thermal treatment conditions. The samples were characterized by XRD, SEM, BET, DTA and TGA. The results presented the attainment of a monophasic powder with particles size around 100 nm. (author)

  19. Morphology, molecular structure, and stable carbon isotopic composition of black carbon (BC) in urban topsoils.

    Science.gov (United States)

    Zong, Yutong; Xiao, Qing; Lu, Shenggao

    2018-02-01

    Urban soils contain significant amounts of black carbon (BC) from biomass and fossil fuel combustion and regard to be a pool of BC. BC in urban soils has multiple effects on environmental processes in urban system, such as global climate change, air quality, and public health. Urban topsoil samples (0-10 cm) were collected from Anshan, Liaoning Province, northeast China, which is one of the most important old steel industrial bases in China. The BC in urban topsoils was extracted using the density method. Their chemical composition, morphology, molecular structure, and stable carbon isotopic composition were examined using elemental analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and stable carbon isotope (δ 13 C). Elemental analysis shows that carbon content in the BC of studied soils ranged from 64.5 to 78.4%, with the average more than 70%. The O/C atomic ratio of BC is on average 0.18. The BC particle displays different morphology, including porous spherical, irregular porous fragmentary, and blocky shapes. The porous spherical BC particles has atomic molar O/C ratio determined by SEM-EDS ranging from 0.04 to 0.37. XRD indicates that BC exists in mainly combining with mineral phases hematite (Fe 2 O 3 ), kaolinite (Al 2 Si 2 O 5 (OH) 4 ), quartz (SiO 2 ), and calcite (CaCO 3 ). The FTIR spectra of BC particles show major bands at approximately 3400 cm -1 (O-H), 2920 cm -1 (C = H), 1600 cm -1 (C = C), 1230 cm -1 (C = O), and 1070 cm -1 (C = O). The stable carbon isotope (δ 13 C) of BC ranges from -24.48 to -23.18‰ with the average of -23.79 ± 0.39‰. The concentration of BC in the industrial area is significantly (p fuel combustion. Results indicated that a combination of atomic O/C ratio, porous structure, and stable carbon isotopic (δ 13 C) of BC could reflect effectively the origin of BC

  20. Carbon nanotubes allow capture of krypton, barium and lead for multichannel biological X-ray fluorescence imaging.

    Science.gov (United States)

    Serpell, Christopher J; Rutte, Reida N; Geraki, Kalotina; Pach, Elzbieta; Martincic, Markus; Kierkowicz, Magdalena; De Munari, Sonia; Wals, Kim; Raj, Ritu; Ballesteros, Belén; Tobias, Gerard; Anthony, Daniel C; Davis, Benjamin G

    2016-10-26

    The desire to study biology in situ has been aided by many imaging techniques. Among these, X-ray fluorescence (XRF) mapping permits observation of elemental distributions in a multichannel manner. However, XRF imaging is underused, in part, because of the difficulty in interpreting maps without an underlying cellular 'blueprint'; this could be supplied using contrast agents. Carbon nanotubes (CNTs) can be filled with a wide range of inorganic materials, and thus can be used as 'contrast agents' if biologically absent elements are encapsulated. Here we show that sealed single-walled CNTs filled with lead, barium and even krypton can be produced, and externally decorated with peptides to provide affinity for sub-cellular targets. The agents are able to highlight specific organelles in multiplexed XRF mapping, and are, in principle, a general and versatile tool for this, and other modes of biological imaging.

  1. Barium aspiration and alveolarisation of barium in an infant: A case report and review of management

    Directory of Open Access Journals (Sweden)

    Alan F. Isles

    2014-05-01

    Full Text Available We describe a case of bilateral inhalation and alveolarisation of barium in an infant following a barium swallow for investigation of dusky spells associated with feeds. A bronchoscopy subsequently revealed the presence of a mid-tracheal tracheo-oesophageal cleft. We review the literature on barium aspiration, its consequences and make recommendations for management.

  2. Origin of thermally stable ferroelectricity in a porous barium titanate thin film synthesized through block copolymer templating

    Directory of Open Access Journals (Sweden)

    Norihiro Suzuki

    2017-07-01

    Full Text Available A porous barium titanate (BaTiO3 thin film was chemically synthesized using a surfactant-assisted sol-gel method in which micelles of amphipathic diblock copolymers served as structure-directing agents. In the Raman spectrum of the porous BaTiO3 thin film, a peak corresponding to the ferroelectric tetragonal phase was observed at around 710 cm−1, and it remained stable at much higher temperature than the Curie temperature of bulk single-crystal BaTiO3 (∼130 °C. Measurements revealed that the ferroelectricity of the BaTiO3 thin film has high thermal stability. By analyzing high-resolution transmission electron microscope images of the BaTiO3 thin film by the fast Fourier transform mapping method, the spatial distribution of stress in the BaTiO3 framework was clearly visualized. Careful analysis also indicated that the porosity in the BaTiO3 thin film introduced anisotropic compressive stress, which deformed the crystals. The resulting elongated unit cell caused further displacement of the Ti4+ cation from the center of the lattice. This displacement increased the electric dipole moment of the BaTiO3 thin film, effectively enhancing its ferro(piezoelectricity.

  3. Activated carbon derived from waste coffee grounds for stable methane storage

    International Nuclear Information System (INIS)

    Kemp, K Christian; Baek, Seung Bin; Lee, Wang-Geun; Kim, Kwang S; Meyyappan, M

    2015-01-01

    An activated carbon material derived from waste coffee grounds is shown to be an effective and stable medium for methane storage. The sample activated at 900 °C displays a surface area of 1040.3 m"2 g"−"1 and a micropore volume of 0.574 cm"3 g"−"1 and exhibits a stable CH_4 adsorption capacity of ∼4.2 mmol g"−"1 at 3.0 MPa and a temperature range of 298 ± 10 K. The same material exhibits an impressive hydrogen storage capacity of 1.75 wt% as well at 77 K and 100 kPa. Here, we also propose a mechanism for the formation of activated carbon from spent coffee grounds. At low temperatures, the material has two distinct types with low and high surface areas; however, activation at elevated temperatures drives off the low surface area carbon, leaving behind the porous high surface area activated carbon. (paper)

  4. Gas thermodesorption study of barium and strontium cerates

    International Nuclear Information System (INIS)

    Aksenova, T.I.; Khromushin, I.V.; Zhotabaev, Zh.R.; Bukenov, K.D.; Medvedeva, Z.V.; Berdauletov, A.K.

    2002-01-01

    Kinetic of water, oxygen, hydrogen and carbon dioxide molecules release from doped and undoped samples of barium cerates and doped strontium cerates during vacuum heating was studied. The samples were prepared by inductive melting method. The following two kinds of preliminary samples treatments were used: annealing in air (650-750 deg. C) and wet nitrogen atmosphere (625 deg.C). Main results of thermodesorption studies of barium and strontium cerates are represented in the table. The samples of doped LaSrMnO were investigated also. It was found that the initial doped samples (without preliminary annealing) did not show any gas release in temperature range of 20-1100 deg. C. This fact indicates on high stability of compositions and strong bond of 'host' oxygen in their lattice. A significant amount of water and oxygen molecules were released from BaCe 0.9 Nd 0.1 O 3 samples whereas water and hydrogen molecules desorption from SrCe 0.95 Y 0.05 O 3 samples took place. Hydrogen molecules desorption was found for strontium cerates samples; no hydrogen molecules release was observed for doped and pure barium cerate samples.Intensive water molecules release from doped samples confirms the necessity of oxygen vacancies creation in these compounds to get properties of proton conductivity, since it was not found any water molecules release from annealed undoped samples of BaCeO 3 It is necessary to notice that oxygen molecules release from these samples took place at ∼1000 deg. C that is significantly higher then from BaCeNdO samples. Forms of high temperatures part of oxygen and low temperature part of water spectra indicate that phase transformations are responsible for oxygen and water molecules desorption in this cases. These results are in good agreement with literature data. Desorption of water molecules from barium and strontium cerates took place. Oxygen desorption took place only from barium cerates. It can be explained as the following: doped barium cerates have

  5. Studying biosphere-atmosphere exchange of CO2 through Carbon-13 stable isotopes

    NARCIS (Netherlands)

    Velde, van der I.R.

    2015-01-01

    Summary Thesis ‘Studying biosphere-atmosphere exchange of CO2 through

    carbon-13 stable isotopes’

    Ivar van der Velde

    Making predictions of future climate is difficult, mainly due to large uncertainties in the carbon cycle. The rate at which carbon is stored in the oceans and

  6. Stable carbon isotope ratios: implications for the source of sediment carbon and for phytoplankton carbon assimilation in Lake Memphremagog, Quebec

    International Nuclear Information System (INIS)

    LaZerte, B.D.

    1983-01-01

    The stable carbon isotope (SCI) ratio of the sediment of Lake Memphremagog, Quebec is compared with that ot terrestrial sources and the phytoplankton to determine the relative proportion of allochthonous carbon incorporated into the sediments. Approximately 40-50% of the organic carbon in the main basins' pelagic sediment was terrestrial in origin, whereas up to 100% was terrestrial in littoral areas. The SCI method of determining the organic carbon source of sediments appears more reliable than the C/N method. A comparison of the SCI fractionation of the phytoplankton with laboratory cultures under different degrees of carbon limitation indicates that the phytoplankton of Lake Memphremagog are not carbon limited and fix carbon primarily by the C 3 pathway

  7. Attainment of barium hexa ferrite nanoparticles by a Pechini method

    International Nuclear Information System (INIS)

    Galvao, Sheila B.; Timoteo, Flavio Junior J.; Machado, Tercio G.; Souto, Kesia K.O.; Floreoto, Neide T.; Paskocimas, Carlos A.

    2009-01-01

    The barium hexa ferrites (BaFe 12 O 19 ) are used as a compound of materials applied in electronic devices, as medical devices, satellites, dada servers systems, wireless systems and others. The general properties are strongly related to the microstructure and morphology, and the particles size decrease results in advantages to the majority applications, mainly the high-tech thumbnail devices. These magnetic ceramic materials, with perovskite structure, are traditionally prepared my conventional oxide mixture synthesis. In this work was studied the nanoparticle synthesis of BaFe 12 O 19 by the precursors polymeric method (Pechini), using as precursors the barium carbonate and the iron nitrate, under different thermal treatment conditions. The samples were characterized by XRD, Raman spectroscopy, SEM, BET, DTA and TGA. The results presented the attainment of a monophasic powder with particles size around 100 nm. (author)

  8. Barium sulfate aspiration: Severe chemical pneumonia induced by a massive reflux of contrast medium during small bowel barium enema.

    Science.gov (United States)

    Zhang, Lin; Yang, Yi; Zhang, Ji; Zhou, Xiaowei; Dong, Hongmei; Zhou, Yiwu

    2015-08-01

    Barium contrast radiography is a conventional procedure aimed at revealing lesions of the alimentary tract using barium sulfate on X-ray irradiation. Although it is widely used in clinics, adverse effects and complications are observed, such as anaphylaxis, granuloma, fecalithes, abdomen-leaking, embolism, bacterial contamination, and aspiration. We report a case of death due to a massive barium sulfate aspiration resulted from an air-barium double contrast enema radiography. A 25-year-old female patient was hospitalized with symptoms of abdominal distention, nausea, vomiting and diarrhea for three days. A progressive respiratory distress presented only 1h after a small bowel air-barium double contrast enema. The patient died 11h later. The result of autopsy revealed the cause of death to be severe chemical pneumonitis induced by gastric fluid which was aspirated into her lungs. Barium sulfate is generally recognized to be chemically inert for the respiratory system, but a mixture of barium sulfate with gastric contents is fatal. Here we intend to suggest that, when determining the potential cause of death, medical examiners should consider a patient's status quo as well as the possible adverse effects and complications caused by the barium sulfate preparation during gastrointestinal radiography. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Bacterial Reduction Of Barium Sulphate By Sulphate-Reducing Bacteria

    Directory of Open Access Journals (Sweden)

    Luptáková Alena

    2015-12-01

    Full Text Available Acid mine drainage (AMD is a worldwide problem leading to contamination of water sources. AMD are characterized by low pH and high content of heavy metals and sulphates. The barium salts application presents one of the methods for the sulphates removing from AMD. Barium chloride, barium hydroxide and barium sulphide are used for the sulphates precipitation in the form of barium sulphate. Because of high investment costs of barium salts, barium sulphide is recycled from barium sulphate precipitates. It can be recycled by thermic or bacterial reduction of barium sulphate. The aim of our study was to verify experimentally the possibility of the bacterial transformation of BaSO4 to BaS by sulphate-reducing bacteria. Applied BaSO4 came from experiments of sulphates removal from Smolnik AMD using BaCl2.

  10. Barium aluminate cement: its application

    International Nuclear Information System (INIS)

    Drozdz, M.; Wolek, W.

    1975-01-01

    The technology of manufacturing barium aluminate cement from barium sulfate and alumina, using a rotary kiln for firing the clinker is described. The method of granulation of the homogenized charge was used. Conditions of using the ''to mud'' method in industry were indicated. The physical and chemical properties of barium aluminate cement are determined and the quality of several batches of cement prepared on a semi-industrial scale and their suitability for making highly refractory concretes are tested. The optimal composition of the concretes is determined as a function of the mixing water and barium aluminate cement contents. Several experimental batches of concretes were used in the linings of furnaces in the steel industry. The suitability of these cements for use in fields other than steelmaking is examined. It is established that calcium aluminate cement has certain limited applications [fr

  11. Analysis of barium by isotope mass spectrometry

    International Nuclear Information System (INIS)

    Long Kaiming; Jia Baoting; Liu Xuemei

    2004-01-01

    The isotopic abundance ratios for barium at sub-microgram level are analyzed by thermal surface ionization mass spectrometry (TIMS). Rhenium trips used for sample preparation are firstly treated to eliminate possible barium background interference. During the preparation of barium samples phosphoric acid is added as an emitting and stabilizing reagent. The addition of phosphoric acid increases the collection efficiency and ion current strength and stability for barium. A relative standard deviation of 0.02% for the isotopic abundance ratio of 137 Ba to 138 Ba is achieved when the 138 Ba ion current is (1-3) x 10 -12 A. The experimental results also demonstrate that the isotope fractionation effect is negligibly small in the isotopic analysis of barium

  12. Oesophageal motility disorders - diagnosis with a barium-rice study

    International Nuclear Information System (INIS)

    Schwickert, H.C.; Schadmand-Fischer, S.; Klose, P.; Staritz, M.; Ueberschaer, B.; Thelen, M.

    1993-01-01

    The purpose of this study was to evaluate the role of a 'barium-rice' study for diagnosis of dysphagia and oesophageal motility disorders. Material and methods: 203 patients with oesophageal motility disorders of various aetiologies were examined by both conventional barium study and a 'barium-rice' study. During the latter, oesophageal clearance of a defined mixture of barium sulfate and boiled rice was measured. Results: The conventional barium study revealed prolonged transit time in only 15.8% (32 of 203 cases), whereas barium-rice study was pathological in 50.8% (103 of 203 cases). In 71 of 171 patients (41.5%) with a normal barium study, barium-rice passage was prolonged. In 23 patients, radiological results were confirmed by manometric measurements. Conclusion: Oesophageal motility disorders are detected by a barim-rice study with high sensitivity independent of the underlying disease. The barium-rice study offers a simple diagnostic tool revealing quantitative and reliable results. The barium-rice study is a suitable method for screening and follow-up of patients with dysphagia and oesophageal motility disorders. (orig.) [de

  13. Effect of sodium bicarbonate pretreatment on barium coating of mucosa during double contrast barium meal

    International Nuclear Information System (INIS)

    Kinnunen, J.; Toetterman, S.; Kaila, R.; Pietilae, J.; Linden, H.; Tervahartiala, P.

    1983-01-01

    The radiographic pattern of the areae gastricae is produced by barium lying in the intersecting furrows of the gastric mucosal surface. However, if the mucus layer on the gastric mucosa is thick, it interferes with the barium coating of the areae gastricae during double contrast barium meal. As sodium bicarbonate decreases the viscosity of mucus and thus may make the gastric mucus layer thinner, it was evaluated as a pretreatment agent in a routine double contrast upper-gastrointestinal study to improve the visualization of the areae gastricae. In a single blind study, 53 of 106 patients took sodium bicarbonate water mixtures at bedtime the day before and on the morning of the examination. According to the results of the present study mucolysis induced by the used doses of sodium bicarbonate does not significantly affect micromucosal visualization during double-contrast barium meal. (orig.) [de

  14. Effect of sodium bicarbonate pretreatment on barium coating of mucosa during double contrast barium meal

    Energy Technology Data Exchange (ETDEWEB)

    Kinnunen, J.; Toetterman, S.; Kaila, R.; Pietilae, J.; Linden, H.; Tervahartiala, P.

    1983-08-01

    The radiographic pattern of the areae gastricae is produced by barium lying in the intersecting furrows of the gastric mucosal surface. However, if the mucus layer on the gastric mucosa is thick, it interferes with the barium coating of the areae gastricae during double contrast barium meal. As sodium bicarbonate decreases the viscosity of mucus and thus may make the gastric mucus layer thinner, it was evaluated as a pretreatment agent in a routine double contrast upper-gastrointestinal study to improve the visualization of the areae gastricae. In a single blind study, 53 of 106 patients took sodium bicarbonate water mixtures at bedtime the day before and on the morning of the examination. According to the results of the present study mucolysis induced by the used doses of sodium bicarbonate does not significantly affect micromucosal visualization during double-contrast barium meal.

  15. Aspiration of Barium Contrast

    Directory of Open Access Journals (Sweden)

    Cristina Fuentes Santos

    2014-01-01

    Full Text Available The aspiration of barium contrast is a rare complication that may occur during studies of the digestive tract. Barium is an inert material that can cause anywhere from an asymptomatic mechanical obstruction to serious symptoms of respiratory distress that can result in patient death. We present the case of a 79-year-old male patient in whom we observed the presence of contrast medium residue in the lung parenchyma as an incidental finding during hospitalization. When the patient’s medical file was reviewed, images were found of a barium swallow study that the patient had undergone months earlier, and we were able to observe the exact moment of the aspiration of the contrast material. The patient had been asymptomatic since the test.

  16. Barite (Barium)

    Science.gov (United States)

    Johnson, Craig A.; Piatak, Nadine M.; Miller, M. Michael; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Barite (barium sulfate, BaSO4) is vital to the oil and gas industry because it is a key constituent of the mud used to drill oil and gas wells. Elemental barium is an additive in optical glass, ceramic glazes, and other products. Within the United States, barite is produced mainly from mines in Nevada. Imports in 2011 (the latest year for which complete data were available) accounted for 78 percent of domestic consumption and came mostly from China.Barite deposits can be divided into the following four main types: bedded-sedimentary; bedded-volcanic; vein, cavity-fill, and metasomatic; and residual. Bedded-sedimentary deposits, which are found in sedimentary rocks with characteristics of high biological productivity during sediment accumulation, are the major sources of barite production and account for the majority of reserves, both in the United States and worldwide. In 2013, China and India were the leading producers of barite, and they have large identified resources that position them to be significant producers for the foreseeable future. The potential for undiscovered barite resources in the United States and in many other countries is considerable, however. The expected tight supply and rising costs in the coming years will likely be met by increased production from such countries as Kazakhstan, Mexico, Morocco, and Vietnam.Barium has limited mobility in the environment and exposed barium in the vicinity of barite mines poses minimal risk to human or ecosystem health. Of greater concern is the potential for acidic metal-bearing drainage at sites where the barite ores or waste rocks contain abundant sulfide minerals. This risk is lessened naturally if the host rocks at the site are acid-neutralizing, and the risk can also be lessened by engineering measures.

  17. [Relationship between Fe, Al oxides and stable organic carbon, nitrogen in the yellow-brown soils].

    Science.gov (United States)

    Heng, Li-Sha; Wang, Dai-Zhang; Jiang, Xin; Rao, Wei; Zhang, Wen-Hao; Guo, Chun-Yan; Li, Teng

    2010-11-01

    The stable organic carbon and nitrogen of the different particles were gained by oxidation of 6% NaOCl in the yellow-brown soils. The relationships between the contents of selective extractable Fe/Al and the stable organic carbon/nitrogen were investigated. It shown that amounts of dithionite-citrate-(Fe(d)) and oxalate-(Fe(o)) and pyrophosphate extractable (Fe(p)) were 6-60.8 g x kg(-1) and 0.13-4.8 g x kg(-1) and 0.03-0.47 g x kg(-1) in 2-250 microm particles, respectively; 43.1-170 g x kg(-1) and 5.9-14.0 g x kg(-1) and 0.28-0.78 g x kg(-1) in soils than in arid yellow-brown soils, and that of selective extractable Al are lower in the former than in the latter. Amounts of the stable organic carbon and nitrogen, higher in paddy yellow-brown soils than in arid yellow-brown soils, were 0.93-6.0 g x kg(-1) and 0.05-0.36 g x kg(-1) in 2-250 microm particles, respectively; 6.05-19.3 g x kg(-1) and 0.61-2.1 g x kg(-1) in stabilization index (SI(C) and SI(N)) of the organic carbon and nitrogen were 14.3-50.0 and 11.9-55.6 in 2-250 microm particles, respectively; 53.72-88.80 and 40.64-70.0 in soils than in paddy yellow-brown soils. The organic carbon and nitrogen are advantageously conserved in paddy yellow-brown soil. An extremely significant positive correlation of the stable organic carbon and nitrogen with selective extractable Fe/Al is observed. The most amounts between the stable organic carbon and nitrogen and selective extractable Fe/Al appear in clay particles, namely the clay particles could protect the soil organic carbon and nitrogen.

  18. Binding and leakage of barium in alginate microbeads.

    Science.gov (United States)

    Mørch, Yrr A; Qi, Meirigeng; Gundersen, Per Ole M; Formo, Kjetil; Lacik, Igor; Skjåk-Braek, Gudmund; Oberholzer, Jose; Strand, Berit L

    2012-11-01

    Microbeads of alginate crosslinked with Ca(2+) and/or Ba(2+) are popular matrices in cell-based therapy. The aim of this study was to quantify the binding of barium in alginate microbeads and its leakage under in vitro and accumulation under in vivo conditions. Low concentrations of barium (1 mM) in combination with calcium (50 mM) and high concentrations of barium (20 mM) in gelling solutions were used for preparation of microbeads made of high-G and high-M alginates. High-G microbeads accumulated barium from gelling solution and contained higher concentrations of divalent ions for both low- and high-Ba exposure compared with high-G microbeads exposed to calcium solely and to high-M microbeads for all gelling conditions. Although most of the unbound divalent ions were removed during the wash and culture steps, leakage of barium was still detected during storage. Barium accumulation in blood and femur bone of mice implanted with high-G beads was found to be dose-dependent. Estimated barium leakage relevant to transplantation to diabetic patients with islets in alginate microbeads showed that the leakage was 2.5 times lower than the tolerable intake value given by WHO for high-G microbeads made using low barium concentration. The similar estimate gave 1.5 times higher than is the tolerable intake value for the high-G microbeads made using high barium concentration. To reduce the risk of barium accumulation that may be of safety concern, the microbeads made of high-G alginate gelled with a combination of calcium and low concentration of barium ions is recommended for islet transplantation. Copyright © 2012 Wiley Periodicals, Inc.

  19. Stable carbon and nitrogen isotopes in vertical peat profiles of natural and drained boreal peatlands

    Science.gov (United States)

    Nykänen, Hannu; Mpamah, Promise; Rissanen, Antti; Pitkänen, Aki; Turunen, Jukka; Simola, Heikki

    2015-04-01

    Peatlands form a significant carbon pool in the global carbon cycle. Change in peat hydrology, due to global warming is projected to change microbiological processes and peat carbon pool. We tested if bulk stable carbon and nitrogen isotopes serve as indicators of severe long term drying in peatlands drained for forestry. Depth profile analysis of peat, for their carbon and nitrogen content as well as their carbon and nitrogen stable isotopic signatures, were conducted for peatlands in southern and eastern Finland, having ombrotrophic and minerotrophic natural and corresponding drained pairs or separate drained sites. The selection of sites allowed us to compare changes due to different fertility and changes due to long term artificial drying. Drainage lasting over 40 years has led to changes in hydrology, vegetation, nutrient mineralization and respiration. Furthermore, increased nutrient uptake and possible recycling of peat nitrogen and carbon trough vegetation back to the peat surface, also possibly has an effect on the stable isotopic composition of peat carbon and nitrogen. We think that drainage induced changes somehow correspond to those caused by changed hydrology due to climate change. We will present data from these measurements and discuss their implications for carbon and nitrogen flows in peatlands.

  20. Elemental and stable isotopic approaches for studying the organic and inorganic carbon components in natural samples

    International Nuclear Information System (INIS)

    Helie, J-F

    2009-01-01

    The carbon cycle is an important part of major biogeochemical cycles. Many techniques may be used to characterize carbon amounts and sources in the environment. Here we first review the most popular techniques for the determination of organic and inorganic carbon concentrations. Decarbonatation techniques are also reviewed in details since it is often an important part of organic carbon analysis. The second part of this paper addresses the use of carbon stable isotopes to characterize organic carbon sources and processes in the environment. An overview of general stable isotopes background and terminology is given as well as the most popular analytical techniques.

  1. Grasland Stable Isotope Flux Measurements: Three Isotopomers of Carbon Dioxide Measured by QCL Spectroscopy

    Science.gov (United States)

    Zeeman, M. J.; Tuzson, B.; Eugster, W.; Werner, R. A.; Buchmann, N.; Emmenegger, L.

    2007-12-01

    To improve our understanding of greenhouse gas dynamics of managed ecosystems such as grasslands, we not only need to investigate the effects of management (e.g., grass cuts) and weather events (e.g., rainy days) on carbon dioxide fluxes, but also need to increase the time resolution of our measurements. Thus, for the first time, we assessed respiration and assimilation fluxes with high time resolution (5Hz) stable isotope measurements at an intensively managed farmland in Switzerland (Chamau, 400m ASL). Two different methods were used to quantify fluxes of carbon dioxide and associated fluxes of stable carbon isotopes: (1) the flux gradient method, and (2) the eddy covariance method. During a week long intensive measurement campaign, we (1) measured mixing ratios of carbon dioxide isotopomers (12C16O2, 12C16O18O, 13C16O2) with a Quantum Cascade Laser (QCL, Aerodyne Inc.) spectroscope and (2) collected air samples for isotope analyses (13C/12C) and (18O/16O) of carbon dioxide by Isotope Ratio Mass Spectrometry (IRMS, Finnigan) every two hours, concurrently along a height profile (z = 0.05; 0.10; 0.31; 2.15m). In the following week, the QCL setup was used for closed-path eddy covariance flux measurement of the carbon dioxide isotopomers, with the air inlet located next to an open-path Infra Red Gas Analyzers (IRGA, LiCor 7500) used simultaneously for carbon dioxide measurements. During this second week, an area of grass inside the footprint was cut and harvested after several days. The first results of in-field continuous QCL measurements of carbon dioxide mixing ratios and their stable isotopic ratios show good agreement with IRGA measurements and isotope analysis of flask samples by IRMS. Thus, QCL spectroscopy is a very promising tool for stable isotope flux investigations.

  2. Stable isotope compositions of organic carbon and contents of ...

    African Journals Online (AJOL)

    The stable isotope compositions of organic carbon (OC), and contents of OC and nitrogen for four sediment cores recovered from lakes Makat (located in the Ngorongoro Crater), Ndutu and Masek (located in the Serengeti Plains) are used to document sources of organic matter (OM) and climatic changes in sub-arid ...

  3. Investigating Pathways of Nutrient and Energy Flows Through Aquatic Food Webs Using Stable Isotopes of Carbon and Nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Hadwen, W. L.; Bunn, S. E. [Australian Rivers Institute, Griffith School of Environment, Griffith University, Nathan Campus, Brisbane, Queensland (Australia)

    2013-05-15

    Carbon and nitrogen stable isotopes can provide valuable insights into pathways of nutrient and energy flows in aquatic ecosystems. Carbon stable isotopes are principally used to trace pathways of organic matter transfer through aquatic food webs, particularly with regard to identifying the dominant sources of nutrition for aquatic biota. Stable isotopes of carbon have been widely used to answer one of the most pressing questions in aquatic food web ecology - to what degree do in-stream (autochthonous) and riparian (allochthonous) sources of energy fuel riverine food webs? In conjunction with carbon stable isotopes, nitrogen stable isotopes have been used to determine the trophic position of consumers and to identify the number of trophic levels in aquatic food webs. More recently, stable nitrogen isotopes have been recommended as indicators of anthropogenic disturbances. Specifically, agricultural land uses and/or sewage effluent discharge have been shown to significantly increase {delta}{sup 15}N signatures in primary producers and higher order consumers in freshwater, estuarine and marine environments. Together, carbon and nitrogen stable isotopes can be used to examine natural food web functions as well as the degree to which human modifications to catchments and aquatic environments can influence aquatic ecosystem function. (author)

  4. Stable carbon, nitrogen and sulfur isotopes in non-carbonate fractions of cold-seep carbonates

    Science.gov (United States)

    Feng, Dong; Peng, Yongbo; Peckmann, Jörn; Roberts, Harry; Chen, Duofu

    2017-04-01

    Sulfate-driven anaerobic oxidation of methane (AOM) supports chemosynthesis-based communities and limits the release of methane from marine sediments. This process promotes the formation of carbonates close to the seafloor along continental margins. The geochemical characteristics of the carbonate minerals of these rocks are increasingly understood, questions remain about the geochemical characteristics of the non-carbonate fractions. Here, we report stable carbon, nitrogen and sulfur isotope patterns in non-carbonate fractions of seep carbonates. The authigenic carbonates were collected from three modern seep provinces (Black Sea, Gulf of Mexico, and South China Sea) and three ancient seep deposits (Marmorito, northern Italy, Miocene; SR4 deposit of the Lincoln Creek Formation and Whiskey Creek, western Washington, USA, Eocene to Oligocene). The δ13C values of non-carbonate fractions range from ˜-25‰ to -80‰ VPDB. These values indicate that fossil methane mixed with varying amounts of pelagic organic matter is the dominant source of carbon in these fractions. The relatively small offset between the δ34S signatures of the non-carbonate fractions and the respective sulfide minerals suggests that locally produced hydrogen sulfide is the main source of sulfur in seep environments. The δ15N values of the non-carbonate fractions are generally lower than the corresponding values of deep-sea sediments, suggesting that organic nitrogen is mostly of a local origin. This study reveals the potential of using δ13C, δ15N, δ34S values to discern seep and non-seep deposits. In cases where δ13Ccarbonate values are only moderately low due to mixing processes and lipid biomarkers have been erased in the course of burial, it is difficult to trace back AOM owing to the lack of other records. This problem is even more pronounced when authigenic carbonate is not available in ancient seep environments. Acknowledgments: The authors thank BOEM and NOAA for their years' support

  5. An easily sintered, chemically stable, barium zirconate-based proton conductor for high-performance proton-conducting solid oxide fuel cells

    KAUST Repository

    Sun, Wenping

    2014-07-25

    Yttrium and indium co-doped barium zirconate is investigated to develop a chemically stable and sintering active proton conductor for solid oxide fuel cells (SOFCs). BaZr0.8Y0.2-xInxO3- δ possesses a pure cubic perovskite structure. The sintering activity of BaZr0.8Y0.2-xInxO3- δ increases significantly with In concentration. BaZr0.8Y0.15In0.05O3- δ (BZYI5) exhibits the highest total electrical conductivity among the sintered oxides. BZYI5 also retains high chemical stability against CO2, vapor, and reduction of H2. The good sintering activity, high conductivity, and chemical stability of BZYI5 facilitate the fabrication of durable SOFCs based on a highly conductive BZYI5 electrolyte film by cost-effective ceramic processes. Fully dense BZYI5 electrolyte film is successfully prepared on the anode substrate by a facile drop-coating technique followed by co-firing at 1400 °C for 5 h in air. The BZYI5 film exhibits one of the highest conductivity among the BaZrO3-based electrolyte films with various sintering aids. BZYI5-based single cells output very encouraging and by far the highest peak power density for BaZrO3-based proton-conducting SOFCs, reaching as high as 379 mW cm-2 at 700 °C. The results demonstrate that Y and In co-doping is an effective strategy for exploring sintering active and chemically stable BaZrO3-based proton conductors for high performance proton-conducting SOFCs. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Anastomotic stenosis of the descending colon caused by barium granuloma formation following barium peritonitis: report of a case.

    Science.gov (United States)

    Kitajima, Toshihiro; Tomizawa, Kenji; Hanaoka, Yutaka; Toda, Shigeo; Matoba, Shuichiro; Kuroyanagi, Hiroya; Oota, Yasunori

    2014-11-01

    Anastomotic stricture reportedly often recurs following barium peritonitis, regardless of whether the anastomotic diameter is initially sufficient. However, the causes of repetitive stricture have not been clarified. We report a case that suggests the pathophysiology of recurrent anastomotic strictures following barium peritonitis. The patient was a 39-year-old Japanese man with idiopathic perforation of the descending colon after undergoing an upper gastrointestinal barium contrast study. After emergency peritoneal lavage and diverting colostomy, created using the perforated region, the patient recovered uneventfully and 3 months later, the colostomy was closed and the perforated colon was resected. However, 7 months after colostomy closure, abdominal distention gradually developed, and colonoscopy revealed an anastomotic stricture. The patient was referred to our hospital where he underwent resection of the anastomotic stricture. The surgical specimen exhibited barium granulomas not only in the subserosa of the entire specimen, but also in the submucosa and lamina propria localized in the anastomotic site. These findings suggest that barium was embedded in the submucosa and lamina propria with manipulation of the stapled anastomosis and that the barium trapped in the anastomotic site caused persistent inflammation, resulting in an anastomotic stricture.

  7. Measurement of organic carbon stable isotope composition of different soil types by EA-IRMS system

    International Nuclear Information System (INIS)

    Qi Biao; Ding Lingling; Cui Jiehua; Wang Yanhong

    2009-01-01

    Element analyzer-isotope ratio mass spectrometers (EA-IRMS) is a rapid and precise method for measuring stable carbon isotope. Pure CO 2 reference gas was calibrated via international standard-Urea, and the δ 13 C us PDB value of pure CO 2 is (-29.523 ± 0.0181)%. Stability and linearity of the EA-IRMS system, precision of δ 13 C measurement for samples were tested through experimental comparison. Moreover, determination method of organic carbon stable isotope in soil was based on the system. The EA-IRMS system had well linearity when ion intensity ranged from 1.0 to 7.0V, and it excelled the total linearity when the ion intensity was from 1.5 to 5.0V, and the accurate result of δ 13 C for sample analysis could be obtained with precision of 0.015%. If carbon content in sample is more than 5μg, the requirement for analyzing accurate result of δ 13 C could be achieved. The organic carbon stable isotope was measured in 18 different types soil samples, the average natural abundance of 13 C was 1.082%, and the organic carbon stable isotope composition was significantly different among different type soils. (authors)

  8. Barium enema findings of milk allergy in infants

    International Nuclear Information System (INIS)

    Kim, Gyoung Ju; Kim, Mi Jeong; Lee, Hee Jung

    2006-01-01

    We wanted to evaluate the barium enema findings of milk allergy in infants. Retrospective evaluation of the plain abdominal radiography and barium enema findings was performed in fifteen young infants suffering with milk allergy. The presence of gaseous distension, rectal gas, paralytic ileus and mechanical obstruction was evaluated on the plain radiography. The presence of spasm, a transitional zone, a reversed rectosigmoid index and mucosal irregularity was analyzed on the barium enema; the presence of barium retention was also evaluated on 24-hour-delayed plain radiography. Paralytic ileus was the most common finding on the plain radiography (93%). On the barium enema, continuous spasm of the colon, ranging from the rectum to the descending colon, was revealed in ten infants (67%). A transitional zone was observed in one infant and a reversed rectosigmoid index was revealed in four. Mucosal irregularity was observed in two infants. Barium retention was demonstrated in 11 of fifteen cases: throughout the entire colon (n = 3), from the rectum to the descending colon (n = 7), and up to the transverse colon (n = 1). The most common barium enema finding of milk allergy in infants was spasm of the distal colon. The other findings were a transitional zone, a reversed rectosigmoid index, mucosal irregularity and barium retention

  9. Late Glacial Tropical Savannas in Sundaland Inferred From Stable Carbon Isotope Records of Cave Guano

    Science.gov (United States)

    Wurster, C. M.; Bird, M. I.; Bull, I.; Dungait, J.; Bryant, C. L.; Ertunç, T.; Hunt, C.; Lewis, H. A.; Paz, V.

    2008-12-01

    During the Last Glacial Period (LGP), reduced global sea level exposed the continental shelf south of Thailand to Sumatra, Java, and Borneo to form the contiguous continent of Sundaland. However, the type and extent of vegetation that existed on much of this exposed landmass during the LGP remains speculative. Extensive bird and bat guano deposits in caves throughout this region span beyond 40,000 yr BP, and contain a wealth of untapped stratigraphic palaeoenvironmental information. Stable carbon isotope ratios of insectivorous bird and bat guano contain a reliable record of the animal's diet and, through non-specific insect predation, reflect the relative abundance of major physiological pathways in plants. Various physiological pathways of carbon fixation in plants yield differing stable carbon isotope ratios. Stable carbon isotope values of C3 plants are lower than C4 vegetation due to different enzymatic discriminations of the heavy isotope through the carbon fixing pathways. In tropical locales, grasses nearly always follow the C4 photosynthetic pathway, whereas tropical rainforest uses C3 photosynthesis, providing a proxy for vegetation and therefore climate change in the past. Here we discuss four guano stable-isotope records, based on insect cuticle and n-alkane analysis, supplemented by pollen analysis. All sites suggest a C3 dominated ecosystem for the Holocene, consistent with the wet tropical forest vegetation present at all locations. Two sites from Palawan Island, Philippines, record stable carbon isotope values of guano that document a drastic change from C3 (forest) to C4 (savanna) dominated ecosystems during the Last Glacial Maximum (LGM). A third location, at Niah Great Cave, Malaysia, indicates C3-dominant vegetation throughout the record, but does display variation in stable carbon isotope values likely linked to humidity changes. A fourth location, Batu Caves in Peninsular Malaysia, also indicates open vegetation during the LGM. Vegetation

  10. Observed Barium Emission Rates

    Science.gov (United States)

    Stenbaek-Nielsen, H. C.; Wescott, E. M.; Hallinan, T. J.

    1993-01-01

    The barium releases from the CRRES satellite have provided an opportunity for verifying theoretically calculated barium ion and neutral emission rates. Spectra of the five Caribbean releases in the summer of 1991 were taken with a spectrograph on board a U.S. Air Force jet aircraft. Because the line of sight release densities are not known, only relative rates could be obtained. The observed relative rates agree well with the theoretically calculated rates and, together with other observations, confirm the earlier detailed theoretical emission rates. The calculated emission rates can thus with good accuracy be used with photometric observations. It has been postulated that charge exchange between neutral barium and oxygen ions represents a significant source for ionization. If so. it should be associated with emissions at 4957.15 A and 5013.00 A, but these emissions were not detected.

  11. Effects of barium concentration on oropharyngeal swallow timing measures.

    Science.gov (United States)

    Stokely, Shauna L; Molfenter, Sonja M; Steele, Catriona M

    2014-02-01

    Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between "thin" (40 % w/v concentration) and "ultrathin" (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; mean age = 31 years) each performed a series of three noncued 5-ml swallows each of ultrathin and thin liquid barium solutions in videofluoroscopy. Timing measures were compared between barium concentrations using a mixed-model ANOVA. The measures of interest were stage transition duration, pharyngeal transit time, and duration of upper esophageal sphincter opening. Significant differences were observed in the timing measures of swallowing with respect to barium concentration. In all cases, longer durations were seen with the higher barium concentration. Barium concentration influences timing parameters in healthy swallowing, even between ultrathin and thin concentrations. Clinicians need to understand and control for the impact of different barium stimuli on swallowing physiology.

  12. Stable carbon isotope fractionation during the biodegradation of lambda-cyhalothrin.

    Science.gov (United States)

    Shen, Xiaoli; Xu, Zemin; Zhang, Xichang; Yang, Fangxing

    2015-11-01

    In this study, the microbial degradation of lambda-cyhalothrin in soil was investigated using compound-specific stable isotope analysis. The results revealed that lambda-cyhalothrin was biodegraded in soil under laboratory conditions. The half-lives of lambda-cyhalothrin were determined to be 49 and 161 days in non-sterile and sterile soils spiked with 2mg/kg lambda-cyhalothrin and 84 and 154 days in non-sterile and sterile soils spiked with 10mg/kg lambda-cyhalothrin, respectively. The biodegradation of lambda-cyhalothrin resulted in carbon isotope fractionation, which shifted from -29.0‰ to -26.5‰ in soil spiked with 2mg/kg lambda-cyhalothrin, and to -27.5‰ with 10mg/kg lambda-cyhalothrin. A relationship was established between the stable carbon isotope fraction and the residual concentrations of lambda-cyhalothrin by the Rayleigh equation in which the carbon isotope enrichment factor ε of the microbial degradation of lambda-cyhalothrin in the soil was calculated as -2.53‰. This study provides an approach to quantitatively evaluate the biodegradation of lambda-cyhalothrin in soil in field studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Distinguishing feral and managed honeybees (Apis mellifera) using stable carbon isotopes

    OpenAIRE

    Anderson , Lucy; Dynes , Travis; Berry , Jennifer; Delaplane , Keith; McCormick , Lydia; Brosi , Berry

    2014-01-01

    International audience; The ability to distinguish feral and managed honeybees (Apis mellifera) has applications in studies of population genetics, parasite transmission, pollination, interspecific interactions, and bee breeding. We evaluated a diagnostic test based on theoretical differences in stable carbon isotope ratios generated by supplemental feeding. We evaluated (1) if carbon isotope ratios can distinguish feral and managed honeybees and (2) the temporal persistence of the signal aft...

  14. Double contrast barium meal and acetylcysteine

    International Nuclear Information System (INIS)

    Kinnunen, J.; Pietilae, J.; Ahovuo, J.; Mankinen, P.; Tervahartiala, P.

    1989-01-01

    In a prospective double blind study, acetylcysteine, a local and systemic respiratory tract mucolytic agent, or a placebo, were given to 100 patients prior to a double contrast barium meal to decrease the gastric mucus viscosity and to make the mucus layer thinner, in order to permit barium to outline the furrows surrounding the areae gastricae instead of the overlying thick mucus. However, acetylcysteine failed to improve either visualization of the areae gastricae or the general quality of the double contrast barium meal. (orig.)

  15. Study on adsorption performance of coal based activated carbon to radioactive iodine and stable iodine

    International Nuclear Information System (INIS)

    Zhou, Junbo; Hao, Shan; Gao, Liping; Zhang, Youchen

    2014-01-01

    Highlights: • The impregnated coal-based activated carbons as adsorbent for removing methyl iodide. • The coal-based activated carbons to remove stable iodine. • Iodine residues are under 0.5 μg/ml after adsorption treatment. • The decontamination factor is much higher than 1000. - Abstract: Nuclear power plant, nuclear reactors and nuclear powered ship exhaust contains a large amount of gaseous radioactive iodine, and can damage to the workplace and the surrounding environment. The quantitative test to remove methyl iodide and the qualitative test for removing stable iodine were investigated using the impregnated coal-based activated carbons and coal-based activated carbons as adsorbents. The research conducted in this work shows that iodine residues were under 0.5 μg/ml after adsorption treatment and the decontamination factor of the coal-based activated carbon for removing the stable iodine was more than 1000, which can achieve the purpose of removing harmful iodine, and satisfy the requirement of gaseous waste treatment of nuclear powered vessel and other nuclear plants

  16. Nanoparticles of barium induce apoptosis in human phagocytes.

    Science.gov (United States)

    Mores, Luana; França, Eduardo Luzia; Silva, Núbia Andrade; Suchara, Eliane Aparecida; Honorio-França, Adenilda Cristina

    2015-01-01

    Nutrients and immunological factors of breast milk are essential for newborn growth and the development of their immune system, but this secretion can contain organic and inorganic toxins such as barium. Colostrum contamination with barium is an important issue to investigate because this naturally occurring element is also associated with human activity and industrial pollution. The study evaluated the administration of barium nanoparticles to colostrum, assessing the viability and functional activity of colostral mononuclear phagocytes. Colostrum was collected from 24 clinically healthy women (aged 18-35 years). Cell viability, superoxide release, intracellular Ca(2+) release, and phagocyte apoptosis were analyzed in the samples. Treatment with barium lowered mononuclear phagocyte viability, increased superoxide release, and reduced intracellular calcium release. In addition, barium increased cell death by apoptosis. These data suggest that nanoparticles of barium in colostrum are toxic to cells, showing the importance of avoiding exposure to this element.

  17. Barium appendicitis after upper gastrointestinal imaging.

    Science.gov (United States)

    Novotny, Nathan M; Lillemoe, Keith D; Falimirski, Mark E

    2010-02-01

    Barium appendicitis (BA) is a rarely seen entity with fewer than 30 reports in the literature. However, it is a known complication of barium imaging. To report a case of BA in a patient whose computed tomography (CT) scan was initially read as foreign body ingestion. An 18-year-old man presented with right lower quadrant pain after upper gastrointestinal imaging 2 weeks prior. A CT scan was obtained of his abdomen and pelvis that revealed a finding that was interpreted as a foreign body at the area of the terminal ileum. A plain X-ray study of the abdomen revealed radiopaque appendicoliths. Pathology confirmed the diagnosis of barium appendicitis. BA is a rare entity and the pathogenesis is unclear. Shorter intervals between barium study and presentation with appendicitis usually correlate with fewer complications. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  18. Stable isotope analysis of Dacryoconarid carbonate microfossils: a new tool for Devonian oxygen and carbon isotope stratigraphy.

    Science.gov (United States)

    Frappier, Amy Benoit; Lindemann, Richard H; Frappier, Brian R

    2015-04-30

    Dacryoconarids are extinct marine zooplankton known from abundant, globally distributed calcite microfossils in the Devonian, but their shell stable isotope composition has not been previously explored. Devonian stable isotope stratigraphy is currently limited to less common invertebrates or bulk rock analyses of uncertain provenance. As with Cenozoic planktonic foraminifera, isotopic analysis of dacryoconarid shells could facilitate higher-resolution, geographically widespread stable isotope records of paleoenvironmental change, including marine hypoxia events, climate changes, and biocrises. We explored the use of Dacryoconarid isotope stratigraphy as a viable method in interpreting paleoenvironments. We applied an established method for determining stable isotope ratios (δ(13) C, δ(18) O values) of small carbonate microfossils to very well-preserved dacryoconarid shells. We analyzed individual calcite shells representing five common genera using a Kiel carbonate device coupled to a MAT 253 isotope ratio mass spectrometer. Calcite shell δ(13) C and δ(18) O values were compared by taxonomic group, rock unit, and locality. Single dacryoconarid calcite shells are suitable for stable isotope analysis using a Kiel-IRMS setup. The dacryoconarid shell δ(13) C values (-4.7 to 2.3‰) and δ(18) O values (-10.3 to -4.8‰) were consistent across taxa, independent of shell size or part, but varied systematically through time. Lower fossil δ(18) O values were associated with warmer water temperature and more variable δ(13) C values were associated with major bioevents. Dacryoconarid δ(13) C and δ(18) O values differed from bulk rock carbonate values. Dacryoconarid individual microfossil δ(13) C and δ(18) O values are highly sensitive to paleoenvironmental changes, thus providing a promising avenue for stable isotope chemostratigraphy to better resolve regional to global paleoceanographic changes throughout the upper Silurian to the upper Devonian. Our results

  19. Cost-effectiveness of barium enemas performed by radiographers

    International Nuclear Information System (INIS)

    Brown, Lorraine; Desai, Sharad

    2002-01-01

    AIM: To assess the cost-effectiveness of barium enemas performed by radiographers compared to those performed by consultant radiologists. METHOD: Prospective study of 200 barium enemas carried out by a senior radiographer and a consultant radiologist. The sample was a consecutive sample of adult out-patients over a 3-month period, with no exclusion. The length of time of the enema and the numbers and grades of staff involved in the procedure were recorded. This was translated into staffing costs using the appropriate pay scales. RESULTS: The barium enemas performed by the superintendent radiographer were more cost-effective than those performed by the consultant radiologist (1406 pounds for 100 radiographer-performed barium enemas compared to 1787 pounds for 100 carried out by the consultant radiologist). CONCLUSION: In terms of staffing costs, radiographers performing barium enemas not only liberates radiologist time, it is also a cost-effective method of providing an out-patient barium enema service. Brown, L. and Desai, S. (2002)

  20. Kinematic and spatial distributions of barium stars - are the barium stars and Am stars related?

    International Nuclear Information System (INIS)

    Hakkila, J.

    1989-01-01

    The possibility of an evolutionary link between Am stars and barium stars is considered, and an examination of previous data suggests that barium star precursors are main-sequence stars of intermediate mass, are most likely A and/or F dwarfs, and are intermediate-mass binaries with close to intermediate orbital separations. The possible role of mass transfer in the later development of Am systems is explored. Mass transfer and loss from systems with a range of masses and orbital separations may explain such statistical peculiarities of barium stars as the large dispersion in absolute magnitude, the large range of elemental abundances from star to star, and the small number of stars with large peculiar velocities. 93 refs

  1. Multi-Stable Conductance States in Metallic Double-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Ci Lijie

    2009-01-01

    Full Text Available Abstract Electrical transport properties of individual metallic double-walled carbon nanotubes (DWCNTs were measured down to liquid helium temperature, and multi-stable conductance states were found in DWCNTs. At a certain temperature, DWCNTs can switch continuously between two or more electronic states, but below certain temperature, DWCNTs are stable only at one of them. The temperature for switching is always different from tube to tube, and even different from thermal cycle to cycle for the same tube. In addition to thermal activation, gate voltage scanning can also realize such switching among different electronic states. The multi-stable conductance states in metallic DWCNTs can be attributed to different Fermi level or occasional scattering centers induced by different configurations between their inner and outer tubes.

  2. The relationship between carbon stable isotope ratios of hatchling down and egg yolk in Black-headed Gulls

    NARCIS (Netherlands)

    Klaassen, M.R.J.; Baarspul, T.; Dekkers, T.; Van Tienen, P.

    2004-01-01

    We reconstructed the nutrient source for egg synthesis by sampling Black-headed Gull (Larus ridibundus) eggs for yolk, analyzing their carbon stable isotope ratio, and comparing that to hatchling down. Most of the variation in carbon stable isotope ratio was explained by differences between nests,

  3. Aspiration of Barium Contrast

    OpenAIRE

    Fuentes Santos, Cristina; Steen, Bárbara

    2014-01-01

    The aspiration of barium contrast is a rare complication that may occur during studies of the digestive tract. Barium is an inert material that can cause anywhere from an asymptomatic mechanical obstruction to serious symptoms of respiratory distress that can result in patient death. We present the case of a 79-year-old male patient in whom we observed the presence of contrast medium residue in the lung parenchyma as an incidental finding during hospitalization. When the patient’s medical fil...

  4. Stable carbon isotope fractionation during the biodegradation of lambda-cyhalothrin

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Xiaoli [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Department of Environmental Engineering, Quzhou University, Quzhou 324000 (China); Xu, Zemin [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Zhang, Xichang [Laboratory for Teaching in Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Fangxing, E-mail: fxyang@zju.edu.cn [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Department of Effect-Directed Analysis, Helmholtz Centre for Environmental Research — UFZ, Leipzig 04318 (Germany)

    2015-11-01

    In this study, the microbial degradation of lambda-cyhalothrin in soil was investigated using compound-specific stable isotope analysis. The results revealed that lambda-cyhalothrin was biodegraded in soil under laboratory conditions. The half-lives of lambda-cyhalothrin were determined to be 49 and 161 days in non-sterile and sterile soils spiked with 2 mg/kg lambda-cyhalothrin and 84 and 154 days in non-sterile and sterile soils spiked with 10 mg/kg lambda-cyhalothrin, respectively. The biodegradation of lambda-cyhalothrin resulted in carbon isotope fractionation, which shifted from − 29.0‰ to − 26.5‰ in soil spiked with 2 mg/kg lambda-cyhalothrin, and to − 27.5‰ with 10 mg/kg lambda-cyhalothrin. A relationship was established between the stable carbon isotope fraction and the residual concentrations of lambda-cyhalothrin by the Rayleigh equation in which the carbon isotope enrichment factor ε of the microbial degradation of lambda-cyhalothrin in the soil was calculated as − 2.53‰. This study provides an approach to quantitatively evaluate the biodegradation of lambda-cyhalothrin in soil in field studies. - Highlights: • Abiotic and biotic degradation of lambda-cyhalothrin were observed in soil. • Biodegradation of lambda-cyhalothrin was evaluated by CSIA. • Biodegradation of lambda-cyhalothrin leads to carbon isotope fractionation. • An enrichment factor ε of lambda-cyhalothrin was determined as − 2.53‰.

  5. Stable carbon isotope fractionation during the biodegradation of lambda-cyhalothrin

    International Nuclear Information System (INIS)

    Shen, Xiaoli; Xu, Zemin; Zhang, Xichang; Yang, Fangxing

    2015-01-01

    In this study, the microbial degradation of lambda-cyhalothrin in soil was investigated using compound-specific stable isotope analysis. The results revealed that lambda-cyhalothrin was biodegraded in soil under laboratory conditions. The half-lives of lambda-cyhalothrin were determined to be 49 and 161 days in non-sterile and sterile soils spiked with 2 mg/kg lambda-cyhalothrin and 84 and 154 days in non-sterile and sterile soils spiked with 10 mg/kg lambda-cyhalothrin, respectively. The biodegradation of lambda-cyhalothrin resulted in carbon isotope fractionation, which shifted from − 29.0‰ to − 26.5‰ in soil spiked with 2 mg/kg lambda-cyhalothrin, and to − 27.5‰ with 10 mg/kg lambda-cyhalothrin. A relationship was established between the stable carbon isotope fraction and the residual concentrations of lambda-cyhalothrin by the Rayleigh equation in which the carbon isotope enrichment factor ε of the microbial degradation of lambda-cyhalothrin in the soil was calculated as − 2.53‰. This study provides an approach to quantitatively evaluate the biodegradation of lambda-cyhalothrin in soil in field studies. - Highlights: • Abiotic and biotic degradation of lambda-cyhalothrin were observed in soil. • Biodegradation of lambda-cyhalothrin was evaluated by CSIA. • Biodegradation of lambda-cyhalothrin leads to carbon isotope fractionation. • An enrichment factor ε of lambda-cyhalothrin was determined as − 2.53‰

  6. Enterogastroesophageal reflux during barium enema: Report of a case

    International Nuclear Information System (INIS)

    Shin, Hyoun Ja; Rhee, Hak Song

    1972-01-01

    Enterogastric reflux during barium enema examination has been ascribed to various causes including incompetence of the ilepcecal valve, shunt, fistula, excessive barium etc. Recently we have encountered a case of complete enterogastroesphageal regurgitation during barium enema examination performed for the reduction of the ileocolic intuosusception in 6 months old baby. The regurgitation occurred only in the first of two barium enema examinations conducted at one month interval for recurring intussusception. The barium-saline solution used in the present study was not more than 350 ml in quantity. No organic or physical causes of such a complete regurgitation could be determined

  7. Laser cooling and trapping of barium

    NARCIS (Netherlands)

    De, Subhadeep

    2008-01-01

    Laser cooling and trapping of heavy alkaline-earth element barium have been demonstrated for the first time ever. For any possible cycling transition in barium that could provide strong cooling forces, the excited state has a very large branching probability to metastable states. Additional lasers

  8. Kinetics of barium sulphate reaction crystallization in crystallizers with internal circulation

    Directory of Open Access Journals (Sweden)

    J. Koralewska

    2008-06-01

    Full Text Available Kinetic calculation results describing the observed nucleation and growth rates of barium sulphate crystals precipitated in an integrated reaction-crystallization process in a barium sulphate-ammonium chloride-water system are presented and analyzed. The scope of experiments included two continuous model DTM-type crystallizers (Draft Tube Magma with internal circulation of the suspension forced by a liquid jet-pump device responsible for stable and intensive enough ascending/descending flow of BaSO4 crystal magma in a mixing chamber. For comparison purposes the experimental data corresponding to a continuous DT (Draft Tube crystallizer with propeller agitator are presented and discussed. The various types of laboratory crystallizers used were fed with concentrated water solution of barium chloride (of 10 or 24 mass % and - in a stoichiometric proportion - crystalline ammonium sulphate, assuming isothermal (348 K and hydrodynamic (average residence time of suspension in a crystallizer: 900 s process conditions. The observed nucleation and growth rates of barium sulphate crystals were estimated on the basis of crystal size distributions (CSDs using convenient calculation scheme derived for an MSMPR (Mixed Suspension Mixed Product Removal model approach. Considering the experimental population density distribution courses, a size-dependent growth (SDG phenomenon was taken into account in the kinetic calculations. Five SDG kinetic models recommended in the accessible literature were used for kinetic parameter values estimation. It was proved statistically, that Rojkowski’s two SDG models (hyperbolic and exponential best suit for our own experimental data description. The experimental data presented can be practically applied for improving the constructions of liquid jet-pump DTM crystallizers recommended for reaction crystallization of sparingly soluble inorganic salts (especially for high concentrations of reaction substrates in the modern

  9. Molecular and stable carbon isotopic characterization of PAH contaminants at McMurdo Station, Antarctica

    International Nuclear Information System (INIS)

    Kim, Moonkoo . E-mail moonkoo.kim@wmich.edu; Kennicutt, Mahlon C.; Qian Yaorong

    2006-01-01

    The molecular and stable carbon isotopic compositions of contaminant polycyclic aromatic hydrocarbons (PAHs) at McMurdo Station, Antarctica were analyzed in samples collected from land and sub-tidal area. PAHs in the study areas were characterized by high amounts of naphthalene and alkylated naphthalenes from petroleum products introduced by human activities in the area. Principal component analysis (PCA) of PAH composition data identified multiple sources of PAH contamination in the study area. Compositional assignments of origins were confirmed using compound specific stable carbon isotopic analysis

  10. Barium determination in gastric contents, blood and urine by inductively coupled plasma mass spectrometry in the case of oral barium chloride poisoning.

    Science.gov (United States)

    Łukasik-Głębocka, Magdalena; Sommerfeld, Karina; Hanć, Anetta; Grzegorowski, Adam; Barałkiewicz, Danuta; Gaca, Michał; Zielińska-Psuja, Barbara

    2014-01-01

    A serious case of barium intoxication from suicidal ingestion is reported. Oral barium chloride poisoning with hypokalemia, neuromuscular and cardiac toxicity, treated with intravenous potassium supplementation and hemodialysis, was confirmed by the determination of barium concentrations in gastric contents, blood, serum and urine using the inductively coupled plasma mass spectrometry method. Barium concentrations in the analyzed specimens were 20.45 µg/L in serum, 150 µg/L in blood, 10,500 µg/L in urine and 63,500 µg/L in gastric contents. Results were compared with barium levels obtained from a non-intoxicated person. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Coprecipitation of iron and silver with barium fluoride

    International Nuclear Information System (INIS)

    Kopilova, N.V.; Khamidov, B.O.; Kashina, Z.A.; Ikrami, D.D.

    1986-01-01

    Distribution of trace contaminants of iron and silver at coprecipitation of barium fluoride is studied in present work. It is defined that iron almost completely coprecipitated with barium fluoride in wide range of ph 5.5-12. Silver coprecipitated with barium fluoride in ph range 4-7. The value of coprecipitation varies from 94% to 100%.

  12. Thermal decomposition of barium ferrate(VI): Mechanism and formation of FeIV intermediate and nanocrystalline Fe2O3 and ferrite

    International Nuclear Information System (INIS)

    Machala, Libor; Sharma, Virender K.; Kuzmann, Ernö; Homonnay, Zoltán; Filip, Jan; Kralchevska, Radina P.

    2016-01-01

    Simple high-valent iron-oxo species, ferrate(VI) (Fe VI O 4 2− , Fe(VI)) has applications in energy storage, organic synthesis, and water purification. Of the various salts of Fe(VI), barium ferrate(VI) (BaFeO 4 ) has also a great potential as a battery material. This paper presents the thermal decomposition of BaFeO 4 in static air and nitrogen atmosphere, monitored by combination of thermal analysis, Mössbauer spectroscopy, X-ray powder diffraction, and electron-microscopic techniques. The formation of Fe IV species in the form of BaFeO 3 was found to be the primary decomposition product of BaFeO 4 at temperature around 190 °C under both studied atmospheres. BaFeO 3 was unstable in air reacting with CO 2 to form barium carbonate and speromagnetic amorphous iron(III) oxide nanoparticles (<5 nm). Above 600 °C, a solid state reaction between BaCO 3 and Fe 2 O 3 occurred, leading to the formation of barium ferrite nanoparticles, BaFe 2 O 4 (20–100 nm). - Highlights: • We explained the mechanism of thermal decomposition of barium ferrate(VI). • We confirmed the formation of Fe(IV) intermediate phase during the decomposition. • The mechanism of the decomposition is influenced by a presence of carbon dioxide.

  13. Barium Sulfate

    Science.gov (United States)

    ... uses a computer to put together x-ray images to create cross-sectional or three dimensional pictures of the inside of the body). Barium sulfate is in a class of medications called radiopaque contrast media. It works by coating the esophagus, stomach, or ...

  14. Synthesis, photoluminescence and magnetic properties of barium vanadate nanoflowers

    International Nuclear Information System (INIS)

    Xu, Jing; Hu, Chenguo; Xi, Yi; Peng, Chen; Wan, Buyong; He, Xiaoshan

    2011-01-01

    Graphical abstract: The flower-shaped barium vanadate was obtained for the first time. The photoluminescence and magnetic properties of the barium vanadate nanoflowers were investigated at room temperature. Research highlights: → In the paper, the flower-shaped barium vanadate were obtained for the first time. The CHM method used here is new and simple for preparation of barium vanadate. → The photoluminescence and magnetic properties of the barium vanadate nanoflowers were investigated at room temperature. The strong bluish-green emission was observed. → The ferromagnetic behavior of the barium vanadate nanoflowers was found with saturation magnetization of about 83.50 x 10 -3 emu/g, coercivity of 18.89 Oe and remnant magnetization of 4.63 x 10 -3 emu/g. → The mechanisms of PL and magnetic property of barium vanadate nanoflowers have been discussed. -- Abstract: The flower-shaped barium vanadate has been obtained by the composite hydroxide mediated (CHM) method from V 2 O 5 and BaCl 2 at 200 o C for 13 h. XRD and XPS spectrum of the as-synthesized sample indicate it is hexagonal Ba 3 V 2 O 8 with small amount of Ba 3 VO 4.8 coexistence. Scan electron microscope and transmission electron microscope display that the flower-shaped crystals are composed of nanosheets with thickness of ∼20 nm. The UV-visible spectrum shows that the barium vanadate sample has two optical gaps (3.85 eV and 3.12 eV). Photoluminescence spectrum of the barium vanadate flowers exhibits a visible light emission centered at 492 and 525 nm which might be attributed to VO 4 tetrahedron with T d symmetry in Ba 3 V 2 O 8 . The ferromagnetic behavior of the barium vanadate nanoflowers has been found with saturation magnetization of about 83.50 x 10 -3 emu/g, coercivity of 18.89 Oe and remnant magnetization of 4.63 x 10 -3 emu/g, which is mainly due to the presence of a non-orthovanadate phase with spin S = 1/2.

  15. Measurement of stable isotope ratio of organic carbon in water samples

    International Nuclear Information System (INIS)

    Fujii, Toshihiro; Otsuki, Akira

    1977-01-01

    A new method for the measurement of stable isotope ratios was investigated and applied to organic carbon's isotope ratio measurements in water samples. A few river water samples from Tsuchiura city were tested. After the wet oxidation of organic carbons to carbon dioxide in a sealed ampoule, the isotope ratios were determined with the gas chromatograph-quadrupole mass spectrometer combined with a total organic carbon analyser, under the dynamic conditions. The GC-MS had been equipped with the multiple ion detector-digital integrator system. The ion intensities at m/e 44 and 45 were simultaneously measured at a switching rate of 1 ms. The measurements with carbon dioxide acquired from sodium carbonate (53 μg) gave the isotope ratios with the variation coefficient of 0.62%. However, the variation coefficients obtained from organic carbons in natural water samples were 2 to 3 times as high as that from sodium carbonate. This method is simple and rapid and may be applied to various fields especially in biology and medicine. (auth.)

  16. 40 CFR 721.10011 - Barium calcium manganese strontium oxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Barium calcium manganese strontium... Specific Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as barium calcium...

  17. History and challenges of barium titanate: Part I

    Directory of Open Access Journals (Sweden)

    Vijatović M.M.

    2008-01-01

    Full Text Available Barium titanate is the first ferroelectric ceramics and a good candidate for a variety of applications due to its excellent dielectric, ferroelectric and piezoelectric properties. Barium titanate is a member of a large family of compounds with the general formula ABO3 called perovskites. Barium titanate can be prepared using different methods. The synthesis method depends on the desired characteristics for the end application. The used method has a significant influence on the structure and properties of barium titanate materials. In this review paper, Part I contains a study of the BaTiO3 structure and frequently used synthesis methods.

  18. Separation of polybrominated diphenyl ethers in fish for compound-specific stable carbon isotope analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yan-Hong [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing, 100049 (China); Luo, Xiao-Jun, E-mail: luoxiaoj@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen, Hua-Shan; Wu, Jiang-Ping; Chen, She-Jun; Mai, Bi-Xian [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2012-05-15

    A separation and isotopic analysis method was developed to accurately measure the stable carbon isotope ratios of polybrominated diphenyl ethers (PBDEs) with three to six substituted bromine atoms in fish samples. Sample extracts were treated with concentrated sulfuric acid to remove lipids, purified using complex silica gel column chromatography, and finally processed using alumina/silica (Al/Si) gel column chromatography. The purities of extracts were verified by gas chromatography and mass spectrometry (GC-MS) in the full-scan mode. The average recoveries of all compounds across the purification method were between 60% and 110%, with the exception of BDE-154. The stable carbon isotopic compositions of PBDEs can be measured with a standard deviation of less than 0.5 Per-Mille-Sign . No significant isotopic fraction was found during the purification of the main PBDE congeners. A significant change in the stable carbon isotope ratio of BDE-47 was observed in fish carcasses compared to the original isotopic signatures, implying that PBDE stable carbon isotopic compositions can be used to trace the biotransformation of PBDEs in biota. - Highlights: Black-Right-Pointing-Pointer A method for the purification of PBDEs for CSIA was developed. Black-Right-Pointing-Pointer The {delta}{sup 13}C of PBDE congeners can be measured with a standard deviation of less than 0.5 Per-Mille-Sign . Black-Right-Pointing-Pointer Common carp were exposed to a PBDE mixture to investigate debromination. Black-Right-Pointing-Pointer Ratios of the {delta}{sup 13}C values can be used to trace the debromination of PBDE in fish.

  19. Blood pressure changes during barium enema

    International Nuclear Information System (INIS)

    Roach, S.C.; Martin, O.J.D.; Owen, A.; Martin, D.F.

    2001-01-01

    AIMS: To document blood pressure changes during barium enema examination and to determine at what point in the examination changes are likely to occur. METHODS AND RESULTS: Blood pressure measurements were taken at seven points during the course of barium enema examination in 107 consecutive patients. We found that patients over the age of 60 years had statistically significant decreases in blood pressure when they were stood up during the course of the examination. Many of these patients were asymptomatic. Patients who had symptoms (15/107, 14%) when standing up had a degree of hypotension. The duration of barium enema examination is longer in those patients who experience symptoms. CONCLUSION: During a barium enema examination hypotension occurs at the point of standing up more frequently in patients over 60 years and in those who suffer symptoms at this time. Patients who fall into one of these groups should be considered at risk of fainting at this point in the examination. A modified technique to avoid standing should be considered in at-risk patients. Roach, S.C. et al. (2001)

  20. Gluten content of barium sulfate suspensions used for barium swallows in patients with celiac disease.

    Science.gov (United States)

    Chiu, Jennifer G; Shin, Yoona; Patel, Priti N; Mangione, Robert A

    2014-01-01

    To determine the availability and accuracy of information provided by hospitals, imaging centers, and manufacturers regarding gluten in barium sulfate suspensions. A total of 105 facilities were contacted via telephone to determine the gluten content of the contrast media used in those facilities. Manufacturers were contacted and their Web sites reviewed to determine the gluten content of their barium products. Thirty-nine percent of the hospitals and 52% of the imaging centers were not aware of the gluten content of the contrast media they used. Twenty-nine-and-a-half percent of the respondents provided the correct gluten content. The manufacturers noted that 5 products were tested and confirmed gluten free, 1 product was not tested but described as gluten free, 1 product's gluten content depended upon its flavor, and 1 product was reported to contain gluten. Clinicians caring for patients with celiac disease or patients who choose to restrict their gluten consumption must ensure that the barium sulfate suspension ingested is gluten free. It can be difficult to determine the gluten content of barium sulfate, as a majority of radiology departments and imaging centers did not know whether the product they use is gluten free. Educating staff members and improving product labeling would benefit the quality of care provided to patients with celiac disease.

  1. Barium transport in the hot spot region of fluorescent lamps

    International Nuclear Information System (INIS)

    Sigeneger, F; Rackow, K; Uhrlandt, D; Ehlbeck, J; Lieder, G

    2010-01-01

    The transport of barium atoms and ions in the vicinity of the hot spot in fluorescent lamps operating at 25 kHz is investigated by a combined experimental and theoretical approach. By laser-induced fluorescence, the particle densities of barium atoms and ions were measured time-resolved at different distances from the spot centre. In addition, the time-dependent cathode fall voltage was measured using an improved band method. The model combines a kinetic part for the electrons with a fluid part for the barium atoms and ions. Both parts are spatially resolved in spherically symmetric geometry. The space-dependent electron Boltzmann equation yields the electron density and the ionization rate coefficient of barium as functions of the cathode fall voltage. These results are used to solve the time-dependent particle balance equations of barium atoms and ions which include the ionization of barium as gain and loss terms, respectively. Good agreement between the measured and calculated particle densities of barium atoms is obtained. A sensitive dependence of the ionization frequency and of the barium particle densities on the cathode fall voltage was found.

  2. Creating unstable velocity-space distributions with barium injections

    International Nuclear Information System (INIS)

    Pongratz, M.B.

    1983-01-01

    Large Debye lengths relative to detector dimensions and the absence of confining walls makes space an attractive laboratory for studying fundamental theories of plasma instabilities. However, natural space plasmas are rarely found displaced from equilibrium enough to permit isolation and diagnosis of the controlling parameters and driving conditions. Furthermore, any plasma or field response to the departure from equilibrium can be masked by noise in the natural system. Active experiments provide a technique for addressing the chicken or egg dilemma. Early thermite barium releases were generally conducted at low altitudes from sounding rockets to trace electric fields passively or to study configuration-space instabilities. One can also study velocity-space instabilities with barium releases. Neutral barium vapor releases wherein a typical speed greatly exceeds the thermal speed can be used to produce barium ion velocity-space distributions that should be subject to a number of microinstabilities. We examine the ion velocity-space distributions resulting from barium injections from orbiting spacecraft and shaped-charges

  3. The synthesis of a tritium, carbon-14, and stable isotope-labeled cathepsin C inhibitors.

    Science.gov (United States)

    Allen, Paul; Bragg, Ryan A; Caffrey, Moya; Ericsson, Cecilia; Hickey, Michael J; Kingston, Lee P; Elmore, Charles S

    2017-02-01

    As part of a medicinal chemistry program aimed at developing a highly potent and selective cathepsin C inhibitor, tritium, carbon-14, and stable isotope-labeled materials were required. The synthesis of tritium-labeled methanesulfonate 5 was achieved via catalytic tritiolysis of a chloro precursor, albeit at a low radiochemical purity of 67%. Tritium-labeled AZD5248 was prepared via a 3-stage synthesis, utilizing amide-directed hydrogen isotope exchange. Carbon-14 and stable isotope-labeled AZD5248 were successfully prepared through modifications of the medicinal chemistry synthetic route, enabling the use of available labeled intermediates. Copyright © 2016 John Wiley & Sons, Ltd.

  4. Evaluation of gastrointestinal tract transit times using barium-impregnated polyethylene spheres and barium sulfate suspension in a domestic pigeon (Columba livia) model.

    Science.gov (United States)

    Bloch, Rebecca A; Cronin, Kimberly; Hoover, John P; Pechman, Robert D; Payton, Mark E

    2010-03-01

    Barium impregnated polyethylene spheres (BIPS) are used in small animal medicine as an alternative to barium sulfate for radiographic studies of the gastrointestinal tract. To determine the usefulness of BIPS as an alternative to barium suspension in measuring gastrointestinal (GI) transit time for avian species, ventrodorsal radiographs were used to follow the passage of BIPS and 30% barium sulfate suspension through the GI tracts of domestic pigeons (Columba livia). Gastrointestinal transit times of thirty 1.5-mm BIPS administered in moistened gelatin capsules and 30% barium sulfate suspension gavaged into the crop were compared in 6 pigeons. Although the barium suspension passed out of the GI tract of all pigeons within 24 hours, the 1.5-mm BIPS remained in the ventriculus for 368.0 +/- 176.8 hours and did not clear the GI tract for 424.0 +/- 204.6 hours. Although the times for passage of BIPS and 30% barium sulfate suspension from the crop into the ventriculus were not significantly different (P = .14), the times for passage of BIPS from the ventriculus into the large intestine-cloaca and for clearance from the GI tract of the pigeons were significantly longer (P barium sulfate suspension. From the results of this study, we conclude that BIPS are not useful for radiographically evaluating GI transit times in pigeons and are unlikely to be useful in other avian species that have a muscular ventriculus. BIPS may or may not be useful for evaluating GI transit times in species that lack a muscular ventriculus.

  5. Dynamical symmetry breaking in barium isotopes

    International Nuclear Information System (INIS)

    Rawat, Bir Singh; Chattopadhyay, P.K.

    1997-01-01

    The isotopes of Xe with mass numbers 124, 126, 128, 130 and the isotopes of barium with mass numbers 128, 130, 132, 134 were shown to correspond to the O(6) dynamical symmetry of IBM. In the investigation of the dynamical symmetry breaking in this region, the barium isotopes for departures from O(6) symmetry have been studied

  6. Stable Carbon Fractionation In Size Segregated Aerosol Particles Produced By Controlled Biomass Burning

    Science.gov (United States)

    Masalaite, Agne; Garbaras, Andrius; Garbariene, Inga; Ceburnis, Darius; Martuzevicius, Dainius; Puida, Egidijus; Kvietkus, Kestutis; Remeikis, Vidmantas

    2014-05-01

    Biomass burning is the largest source of primary fine fraction carbonaceous particles and the second largest source of trace gases in the global atmosphere with a strong effect not only on the regional scale but also in areas distant from the source . Many studies have often assumed no significant carbon isotope fractionation occurring between black carbon and the original vegetation during combustion. However, other studies suggested that stable carbon isotope ratios of char or BC may not reliably reflect carbon isotopic signatures of the source vegetation. Overall, the apparently conflicting results throughout the literature regarding the observed fractionation suggest that combustion conditions may be responsible for the observed effects. The purpose of the present study was to gather more quantitative information on carbonaceous aerosols produced in controlled biomass burning, thereby having a potential impact on interpreting ambient atmospheric observations. Seven different biomass fuel types were burned under controlled conditions to determine the effect of the biomass type on the emitted particulate matter mass and stable carbon isotope composition of bulk and size segregated particles. Size segregated aerosol particles were collected using the total suspended particle (TSP) sampler and a micro-orifice uniform deposit impactor (MOUDI). The results demonstrated that particle emissions were dominated by the submicron particles in all biomass types. However, significant differences in emissions of submicron particles and their dominant sizes were found between different biomass fuels. The largest negative fractionation was obtained for the wood pellet fuel type while the largest positive isotopic fractionation was observed during the buckwheat shells combustion. The carbon isotope composition of MOUDI samples compared very well with isotope composition of TSP samples indicating consistency of the results. The measurements of the stable carbon isotope ratio in

  7. Late changes in barium sulfate aspiration: HRCT features

    International Nuclear Information System (INIS)

    Voloudaki, A.; Ergazakis, N.; Gourtsoyiannis, N.

    2003-01-01

    Aspiration of barium sulfate occurs accidentally. Lung reaction is usually mild in the early phase due to inert character of the substance and long-term reactions or late toxicities are not expected. Little if any fibrotic response is speculated. We present a case with barium aspiration, studied by high-resolution computed tomography (HRCT) 1 year after the event, as late pulmonary sequelae studied by CT have not been described yet, to the best of our knowledge. The HRCT revealed thickened interlobular septa, subpleural lines, subpleural cysts, and centrilobular micronodules along with barium particles in a subpleural distribution. Those findings indicated that barium is capable of producing mild though silent clinically fibrosis. (orig.)

  8. Placement of radium/barium sludges in tailings areas

    International Nuclear Information System (INIS)

    Murphy, K.L.; Multamaki, G.E.

    1980-01-01

    Currently radium is removed from uranium mining and milling effluents by the addition of barium chloride to precipitate the radium as radium/barium sulphate. The precipitate is allowed to settle in sedimentation basins prior to discharge of the effluent. The sedimentation basins are not suitable for final disposal of the sludge, and placement of the sludges in the tailings area has been proposed. The geochemical environment of fresh tailings areas was characterized as an acidic, oxidized surface zone underlain by an alkaline, reduced zone comprising the rest of the tailings. The quantity of sludge produced was estimated to be small relative to the quantity of tailings, and therefor a relatively small amount of radium would be added to the tailings disposal area by the addition of sludge. To confirm whether sludge addition affected radionuclide solubilization, laboratory leaching tests were conducted on slurries of acid leach tailings, and sludge-tailings mixtures. Radium in the (Ra,Ba)SO 4 sludge was at least as stable as radium in the tailings, and the sludge was able to absorb radium released from the tailings. The addition of sludge did not affect uranium and thorium solubilization. From these results it appears that the placement of sludge in tailings areas would not adversely affect the stability of radionuclides in the tailings or sludge. (auth)

  9. Characterization of barium titanate powder doped with sodium and potassium ions by using Rietveld refining; Caracterizacao do po de titanato de bario dopado com ions sodio e potasio com o refinamento de Rietveld

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, M.C.; Assis, J.T.; Pereira, F.R., E-mail: mcalixto@iprj.uerj.b [Universidade do Estado do Rio de Janeiro (IPRJ/UERJ), Nova Friburgo, RJ (Brazil). Instituto Politecnico; Araujo, J.C. [Universidade do Estado do Rio de Janeiro (FFP/UERJ), Sao Goncalo, RJ (Brazil). Fac. de Formacao de Professores; Moreira, E.L.; Moraes, V.C.A.; Lopes, A.R. [Centro Brasileiro de Pesquisas Fisicas (CBPF/MCT), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    A solid-reaction synthesis of doped barium titanate was done by employing barium carbonates, sodium, potassium and titanium oxides with classic procedures. Rietveld refining of X ray diffraction data of perovskite samples with tetragonal symmetry was applying and show good agreement. Besides, the treatment performed from 600 deg C produces nanocrystals of barium titanate with average size of 33 nm. The presence of endothermic peaks related to BaTiO{sub 3} formation at relatively low temperatures was determined by thermal analysis. A pseudo-Voigt Thompson-Cox-Hastings function was used to fit the standard samples of barium titanate. The Rietveld method has showed be efficient to detect the influences of temperature and doping on barium titanate microstructures. (author)

  10. Barium low concentration determination in solutions using X rays energy spectrometry

    International Nuclear Information System (INIS)

    Barbosa, Joao Batista Santos; Pereira, Jose dos Santos Jorge

    1999-01-01

    This work was proposed to establish an analytical methodology for barium determination in samples from the Waste Supervision of CDTN. Barium is the focus here because it has the same chemical behaviour as radium. Therefore, barium can replace it as an inactive tracer in contention matrix studies. The methodology is made up of two phases; physical concentration and barium determination by an Energy Dispersive Spectrometer using an Am 241 photon excitation system. A very good set of results is found when Am 241 is used in fluorescing barium atoms. This fact, in addition to the physical concentration process, allows to detect up 12 ppb of elementary barium. (author)

  11. Electrooptic and piezoelectric measurements in photorefractive barium titanate and strontium barium niobate

    International Nuclear Information System (INIS)

    Ducharme, S.; Feinberg, J.; Neurgaonkar, R.R.

    1987-01-01

    The authors measured the low-frequency (''unclamped'') electrooptic and piezoelectric coefficients in undoped BaTiO/sub 3/ and Sr/sub x/Ba/sub 1-x/Nb/sub 2/O/sub 6/ (chi - 0.61) crystals using interferometric techniques. The contribution of the piezoelectric effect to the Pockels measurement is discussed. For an applied ac electric field in the range 0.1-200 V/cm, the electrooptic and piezoelectric effects are linear in the magnitude of of the applied field and independent of its frequency in the range of 10 Hz-100 kHz. The unclamped electrooptic coefficients of poled BaTiO/sub 3/ single crystals are r/sub 13/ = 19.5 +- 1 pm/V and r/sub 33/ = 97 +- 7 pm/V, and for strontium barium niobate are r/sub 13/ = 47 +- 5 pm/V and r/sub 33/ = 235 +- 21 pm/V, all measured at a wavelength of 514.5 nm and at T = 23 0 C. For the barium titanate samples the measured Pockels coefficient r/sub c/ identical to r/sub 33/ - (n/sub 1//n/sub 3/)/sup 3/r/sub 13/ = 79 +- 6 pm/V in good agreement with the value r/sub c/ = 76 +- 7 pm/V computed from the above values of r/sub 13/ and r/sub 33/, where n/sub 1/ and n/sub 3/ are the ordinary and extraordinary indexes of refraction, respectively. The measured piezoelectric coefficient is d/sub 23/ = +28.7 +- 2 pm/V for barium titanate, and is d/sub 23/ = +24.6 +- 2 pm/V for strontium barium niobate. They also measured the photoreflective coupling of two optical beams in the crystals, and they show that the dependence of the coupling strength on beam polarization is in fair agreement with the measured values of the Pockels coefficients

  12. Influence of barium substitution on bioactivity, thermal and physico-mechanical properties of bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Arepalli, Sampath Kumar, E-mail: askumar.rs.cer11@iitbhu.ac.in; Tripathi, Himanshu; Vyas, Vikash Kumar; Jain, Shubham; Suman, Shyam Kumar; Pyare, Ram; Singh, S.P., E-mail: spsinghceram@gmail.com

    2015-04-01

    Barium with low concentration in the glasses acts as a muscle stimulant and is found in human teeth. We have made a primary study by substituting barium in the bioactive glass. The chemical composition containing (46.1 − X) SiO{sub 2−}–24.3 Na{sub 2}O–26.9 CaO–2.6 P{sub 2}O{sub 5}, where X = 0, 0.4, 0.8, 1.2 and 1.6 mol% of BaO was chosen and melted in an electric furnace at 1400 ± 5 °C. The glasses were characterized to determine their use in biomedical applications. The nucleation and crystallization regimes were determined by DTA and the controlled crystallization was carried out by suitable heat treatment. The crystalline phase formed was identified by using XRD technique. Bioactivity of these glasses was assessed by immersion in simulated body fluid (SBF) for various time periods. The formation of hydroxy carbonate apatite (HCA) layer was identified by FTIR spectrometry, scanning electron microscope (SEM) and XRD which showed the presence of HCA as the main phase in all tested bioactive glass samples. Flexural strength and densities of bioactive glasses have been measured and found to increase with increasing the barium content. The human blood compatibility of the samples was evaluated and found to be pertinent. - Highlights: • In vitro bioactivity of soda-lime–baria-phospho-silicate glass was investigated. • HCA formed on surface of glasses was confirmed by XRD, SEM and FTIR spectrometry. • Mechanical properties of glasses were found to increase with barium addition. • Hemolysis showed that 1.2 mol% BaO bioactive glass exhibited better biocompatibility. • Barium substituted bioactive glasses can be used as bone implants.

  13. Gastrointestinal tract wall visualization and distention during abdominal and pelvic multidetector CT with a neutral barium sulphate suspension: comparison with positive barium sulphate suspension and with water.

    Science.gov (United States)

    Oliva, M R; Erturk, S M; Ichikawa, T; Rocha, T; Ros, P R; Silverman, S G; Mortele, K J

    2012-01-01

    When examining patients with contrast-enhanced multidetector-row CT, we determined if the stomach and small bowel were visualized and distended better with a neutral barium sulphate suspension than with positive barium sulphate suspension or water. After obtaining approval from our institutional review board, 156 patients (women: 84; mean age: 54 yrs) with no history of gastrointestinal tract disease were randomized prospectively to receive orally either 900 ml of neutral (0.1% w/v) barium sulphate suspension (n = 53), 900 ml of positive (2.1% w/v) barium sulphate suspension (n = 53), or 900 ml of water (n = 50), prior to undergoing contrast-enhanced abdominal and pelvic multidetector-row CT. Two independent radiologists evaluated the stomach, and small bowel, for luminal distension and wall visualization, using a five point scale. Results were compared using Kruskal-Wallis and Mann-Whitney U tests. The walls of the stomach, and small bowel were visualized better in patients who were administered neutral barium sulphate suspension than those who were administered either positive barium sulphate suspension (p barium sulphate suspension, the stomach and small bowel were distended better compared to patients administered water (p barium sulphate suspension (p contrast-enhanced abdominal and pelvic multidetector-row CT, orally administered neutral barium sulphate suspension allows the gastrointestinal tract to be visualized and distended better than either positive barium sulphate suspension, or water.

  14. Barium and radium migration in unconsolidated Canadian geological materials

    International Nuclear Information System (INIS)

    Gillham, R.W.; Sharma, H.D.; Reddy, M.R.; Cooper, E.L.; Cherry, J.A.

    1981-05-01

    This report describes the results of laboratory studies on the distribution coefficients of radium and barium in samples of unconsolidated geologic materials. Graphs of Ksub(d) versus solution concentration for the respective elements showed constant Ksub(d) values in the low concentration range suggesting that, at low concentrations, a distribution coefficient is a valid means of representing the geochemical reactions of both barium and radium. The Ksub(d) values for barium range between 60 and 3500 ml/g. The values appear to be influenced by the amount of barium occurring naturally in the soil materials and thus there is little possiblility of using barium as an analog of radium in laboratory experiments. The Ksub(d) values of radium vary from 50 to 1000 ml/g indicating that a wide range of geological materials have a substantial capacity to retard the migration of radium

  15. Time requirement for barium reduction in intussusception

    International Nuclear Information System (INIS)

    Hwang, Hye Eun; Kim, Seung Ho; Kang, In Young; Park, Byoung Lan; Kim, Byoung Geun

    1988-01-01

    During the period between January 1985 and December 1987, barium reduction was performed in 146 cases of intussusception who were admitted to Kwangju Christian Hospital. The results were as follows: 1. Success rate to the symptom duration is relatively constant. 2. The success rate in infants with severe dehydration was 50% but it was gradually increased in infants with moderate dehydration and in infants with mild dehydration, 83.3% and 100% respectively. 3. The success rate of 12 cases in severely dehydrated infants with positive dissection sign was 16.7%. 4. The success rate of 15 cases in moderately dehydrated infants with positive dissection sign was 66.7%. 5. The average time requirement for barium reduction was 58.3 minutes. No serious complications were noted during barium reduction, except mild vomiting. 6. With above results, it is desirable that barium reduction should be performed according to the patient's physical status and radiologic findings.

  16. Radiation doses to patients undergoing barium meal and barium enema examinations

    International Nuclear Information System (INIS)

    Delichas, M. G.; Hatziioannou, K.; Papanastassiou, E.; Albanopoulou, P.; Chatzi, E.; Sioundas, A.; Psarrakos, K.

    2004-01-01

    The radiation doses received by patients during 41 barium meal (BM) and 42 barium enema (BE) examinations in two Greek hospitals are presented. Radiation dose was measured in terms of the dose area product (DAP). The effective dose and doses to certain organs were estimated using the ODS-60 software. Mean total DAP values were found to be 25 ± 11 Gy cm 2 for BM and 60 ± 35 Gy cm 2 for BE examinations, whereas the estimated mean values of effective dose were 8.6 ± 4.0 and 24 ± 16 mSv respectively. DAP to effective dose conversion coefficients were estimated to be 0.34 mSv per Gy cm 2 for BM and 0.41 mSv per Gy cm 2 for BE. (authors)

  17. LBA-ECO CD-02 Carbon, Nitrogen, Oxygen Stable Isotopes in Organic Material, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set reports the measurement of stable carbon, nitrogen, and oxygen isotope ratios in organic material (plant, litter and soil samples) in forest canopy...

  18. LBA-ECO CD-02 Carbon, Nitrogen, Oxygen Stable Isotopes in Organic Material, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set reports the measurement of stable carbon, nitrogen, and oxygen isotope ratios in organic material (plant, litter and soil samples) in forest...

  19. Barium peritonitis following upper gastrointestinal series: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Su Jin; Hwang, Ji Young; Kim, Yong Jin; Hong, Seong Sook [Soonchunhyang University College of Medicine, Seoul Hospital, Seoul (Korea, Republic of)

    2017-06-15

    We report a rare case of barium peritonitis following an upper gastrointestinal (GI) series and its imaging findings in a 74-year-old female. Barium peritonitis is a rare but life-threatening complication of GI contrast investigation. Therefore, clinical awareness of barium peritonitis as a complication of GI tract contrast investigation would help to prevent such a complication and manage the patients properly.

  20. Barium peritonitis following upper gastrointestinal series: A case report

    International Nuclear Information System (INIS)

    Ko, Su Jin; Hwang, Ji Young; Kim, Yong Jin; Hong, Seong Sook

    2017-01-01

    We report a rare case of barium peritonitis following an upper gastrointestinal (GI) series and its imaging findings in a 74-year-old female. Barium peritonitis is a rare but life-threatening complication of GI contrast investigation. Therefore, clinical awareness of barium peritonitis as a complication of GI tract contrast investigation would help to prevent such a complication and manage the patients properly

  1. A free-air system for long-term stable carbon isotope labeling of adult forest trees

    Science.gov (United States)

    Stable carbon (C) isotopes, in particular employed in labeling experiments, are an ideal tool to broaden our understanding of C dynamics in trees and forest ecosystems. Here, we present a free-air exposure system, named isoFACE, designed for long-term stable C isotope labeling in...

  2. Changes of stable isotopes carbon-13 and nitrogen-15 in different tissues of cattle

    International Nuclear Information System (INIS)

    Sun Fengmei; Yu Hongxia; Wu Wei; Yang Shuming

    2009-01-01

    Stable isotope analysis is a potential tool for tracing food origin. The stable carbon and nitrogen isotope composition in different tissues of two varieties of cattle under the same culture condition were investigated. δ 13 C and δ 15 N values of different defatted muscle and crude fat, cattle tail hair, blood, liver and feed were determined by isotope ratio mass spectrometry, and statistical analysis was carried out. The results showed that stable isotopes of carbon and nitrogen composition was not affected by cattle variety; the δ 13 C values between different defatted muscle, blood, liver and cattle hair were not significantly different, but δ 15 N value in the liver was much higher than other muscle and the δ 13 C values didn't show difference among all the crude fat samples. So these results indicated that isotope fractionation in the various tissue was discrepant. (authors)

  3. Multi-proxy approach (Thorium-234, excess Barium) of export and remineralisation fluxes of carbon and biogenic elements associated with the oceanic biological pump

    International Nuclear Information System (INIS)

    Lemaitre, Nolwenn

    2017-01-01

    The main objective of this thesis is to improve our understanding of the different controls that affect the oceanic biological carbon pump. Particulate export and remineralisation fluxes were investigated using the thorium-234 ( 234 Th) and biogenic barium (Baxs) proxies. In the North Atlantic, the highest particulate organic carbon (POC) export fluxes were associated to biogenic (biogenic silica or calcium carbonate) and lithogenic minerals, ballasting the particles. Export efficiency was generally low (≤ 10%) and inversely related to primary production, highlighting a phase lag between production and export. The highest transfer efficiencies, i.e. the fraction of POC that reached 400 m, were driven by sinking particles ballasted by calcite or lithogenic minerals. The regional variation of meso-pelagic remineralisation was attributed to changes in bloom intensity, phytoplankton cell size, community structure and physical forcing (down-welling). Carbon remineralisation balanced, or even exceeded, POC export, highlighting the impact of meso-pelagic remineralisation on the biological pump with a near-zero, deep carbon sequestration for spring 2014. Export of trace metals appeared strongly influenced by lithogenic material advected from the margins. However, at open ocean stations not influenced by lithogenic matter, trace metal export rather depended on phytoplankton activity and biomass. A last part of this work focused on export of biogenic silica, particulate nitrogen and iron near the Kerguelen Island. This area is characterized by a natural iron-fertilization that increases export fluxes. Inside the fertilized area, flux variability is related to phytoplankton community composition. (author)

  4. Stable carbon isotope composition of organic material and carbonate in sediment of a swamp and lakes in Honshu island, Japan

    International Nuclear Information System (INIS)

    Ishizuka, Toshio

    1978-01-01

    Recent sediments from a swamp and lakes in Honshu were analyzed for organic carbon and carbonate contents, and stable isotope ratios of carbon in the organic materials and carbonate. delta C 13 values of the carbonate tend to be distinctly larger than those of organic carbon in reducing condition as natural gas field, whereas in oxidizing SO 4 -reducing conditions, they are slightly larger than those of organic carbon within the limited range of a few per mil. Carbon isotopic compositions of organic carbon in sediment of the swamp, Obuchi-numa, were analyzed and compared with habitat analysis of associated fossil diatoms. deltaC 13 values of organic carbon in the sediment vary in correlation with the species abundance in habitat of the associated fossil diatoms, ranging from fresh-water (-0.0282) to coastal marine (-0.0236) via brackish. (auth.)

  5. Stable carbon isotope signals in particulate organic and inorganic carbon of coccolithophores - A numerical model study for Emiliania huxleyi.

    Science.gov (United States)

    Holtz, Lena-Maria; Wolf-Gladrow, Dieter; Thoms, Silke

    2017-05-07

    A recent numerical cell model, which explains observed light and carbonate system effects on particulate organic and inorganic carbon (POC and PIC) production rates under the assumption of internal pH homeostasis, is extended for stable carbon isotopes ( 12 C, 13 C). Aim of the present study is to mechanistically understand the stable carbon isotopic fractionation signal (ε) in POC and PIC and furthermore the vital effect(s) included in measured ε PIC values. The virtual cell is divided into four compartments, for each of which the 12 C as well as the 13 C carbonate system kinetics are implemented. The compartments are connected to each other via trans-membrane fluxes. In contrast to existing carbon fractionation models, the presented model calculates the disequilibrium state for both carbonate systems and for each compartment. It furthermore calculates POC and PIC production rates as well as ε POC and ε PIC as a function of given light conditions and the compositions of the external carbonate system. Measured POC and PIC production rates as well as ε PIC values are reproduced well by the model (comparison with literature data). The observed light effect on ε POC (increase of ε POC with increasing light intensities), however, is not reproduced by the basic model set-up, which is solely based on RubisCO fractionation. When extending the latter set-up by assuming that biological fractionation includes further carbon fractionation steps besides the one of RubisCO, the observed light effect on ε POC is also reproduced. By means of the extended model version, four different vital effects that superimpose each other in a real cell can be detected. Finally, we discuss potential limitations of the ε PIC proxy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Springtime carbon emission episodes at the Gosan background site revealed by total carbon, stable carbon isotopic composition, and thermal characteristics of carbonaceous particles

    Directory of Open Access Journals (Sweden)

    J. Jung

    2011-11-01

    Full Text Available In order to investigate the emission of carbonaceous aerosols at the Gosan background super-site (33.17° N, 126.10° E in East Asia, total suspended particles (TSP were collected during spring of 2007 and 2008 and analyzed for particulate organic carbon, elemental carbon, total carbon (TC, total nitrogen (TN, and stable carbon isotopic composition (δ13C of TC. The stable carbon isotopic composition of TC (δ13CTC was found to be lowest during pollen emission episodes (range: −26.2‰ to −23.5‰, avg. −25.2 ± 0.9‰, approaching those of the airborne pollen (−28.0‰ collected at the Gosan site. Based on a carbon isotope mass balance equation, we found that ~42% of TC in the TSP samples during the pollen episodes was attributed to airborne pollen from Japanese cedar trees planted around tangerine farms in Jeju Island. A negative correlation between the citric acid-carbon/TC ratios and δ13CTC was obtained during the pollen episodes. These results suggest that citric acid emitted from tangerine fruit may be adsorbed on the airborne pollen and then transported to the Gosan site. Thermal evolution patterns of organic carbon during the pollen episodes were characterized by high OC evolution in the OC2 temperature step (450 °C. Since thermal evolution patterns of organic aerosols are highly influenced by their molecular weight, they can be used as additional information on the formation of secondary organic aerosols and the effect of aging of organic aerosols during the long-range atmospheric transport and sources of organic aerosols.

  7. Patterns in Stable Isotope Values of Nitrogen and Carbon in ...

    Science.gov (United States)

    Stable isotope measurements of nitrogen and carbon (15N, 13ddC) are often used to characterize estuarine, nearshore, and open ocean ecosystems. Reliable information about the spatial distribution of base-level stable isotope values, often represented by primary producers, is critical to interpreting values in these ecosystems. While base-level isotope data are generally readily available for estuaries, nearshore coastal waters, and the open ocean, the continental shelf is less studied. To address this, and as a first step toward developing a surrogate for base-level isotopic signature in this region, we collected surface and deep water samples from the United States’ eastern continental shelf in the Western Atlantic Ocean, from the Gulf of Maine to Cape Hatteras, periodically between 2000 and 2013. During the study, particulate matter 15dN values ranged from 0.8 to 17.4‰, and 13dC values from −26.4 to −15.6‰over the region. We used spatial autocorrelation analysis and random forest modeling to examine the spatial trends and potential environmental drivers of the stable isotope values. We observed general trends toward lower values for both nitrogen and carbon isotopes at the seaward edge of the shelf. Conversely, higher 15dN and 13dC values were observed on the landward edge of the shelf, in particular in the southern portion of the sampling area. Across all sites, the magnitude of the difference between the 15dN of subsurface and surface particulate m

  8. Air (CO2) double-contrast barium enteroclysis.

    Science.gov (United States)

    Maglinte, Dean D T; Kohli, Marc D; Romano, Stefania; Lappas, John C

    2009-09-01

    In the 1980s and 1990s in North America and Europe, air (CO(2)) double-contrast barium enteroclysis took a back seat to biphasic methylcellulose double-contrast enteroclysis in the investigation of small-bowel diseases. The widespread application of capsule endoscopy in the 21st century has identified a number of limitations of radiologic examinations in the investigation of mucosal diseases of the small intestine. Evidence-based studies comparing barium, computed tomographic (CT), and magnetic resonance (MR) enteroclysis have shown that in spite of improvements in small-bowel examination methods using CT and MR, barium examinations remain superior in the depiction of mucosal abnormalities, particularly the apthoid lesions of early Crohn disease. Barium small-bowel examinations have been recommended in the patient with a negative CT or MR enteroclysis study where the pretest probability of Crohn disease is high. A recent prospective comparison of methylcellulose double-contrast barium enteroclysis to capsule endoscopy with review of the literature has shown that air enteroclysis depicts mucosal details better than does methylcellulose double-contrast enteroclysis because of the "washout" effect of methylcellulose on superficial mucosal features. Recent articles have shown that air enteroclysis compares favorably with wireless capsule endoscopy and double-balloon endoscopy in the diagnosis of mucosal abnormalities of the small bowel. This article describes the authors' technique of performing air double-contrast enteroclysis, its clinical indications, and its pitfalls.

  9. Stable single helical C- and I-chains inside single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Yao Z; Li Y; Jing X D; Meng F S; Zhao X; Li J H; Qiu Z Y; Yuan Q; Wang W X; Bi L; Liu H; Zhang Y P; Liu C J; Zheng S P; Liu B B

    2016-01-01

    The helicity of stable single helical carbon chains and iodine chains inside single-walled carbon nanotubes (SWCNTs) is studied by calculating the systematic van der Waals interaction energy. The results show that the optimal helical radius increases linearly with increasing tube radius, which produces a constant separation between the chain structure and the tube wall. The helical angle exhibits a ladder-like decrease with increasing tube radius, indicating that a large tube can produce a small helicity in the helical structures. (paper)

  10. Surface studies of barium and barium oxide on tungsten and its application to understanding the mechanism of operation of an impregnated tungsten cathode

    Science.gov (United States)

    Forman, R.

    1976-01-01

    Surface studies have been made of multilayer and monolayer films of barium and barium oxide on a tungsten substrate. The purpose of the investigation was to synthesize the surface conditions that exist on an activated impregnated tungsten cathode and obtain a better understanding of the mechanism of operation of such cathodes. The techniques employed in these measurements were Auger spectroscopy and work-function measurements. The results of this study show that the surface of an impregnated cathode is identical to that observed for a synthesized monolayer or partial monolayer of barium on oxidized tungsten by evaluating Auger spectra and work-function measurements. Data obtained from desorption studies of barium monolayers on a tungsten substrate in conjunction with Auger and work-function results have been interpreted to show that throughout most of its life an impreganated cathode has a partial monolayer, rather than a monolayer, of barium on its surface.

  11. Effectiveness of therapeutic barium enema for diverticular hemorrhage.

    Science.gov (United States)

    Matsuura, Mizue; Inamori, Masahiko; Nakajima, Atsushi; Komiya, Yasuhiko; Inoh, Yumi; Kawasima, Keigo; Naitoh, Mai; Fujita, Yuji; Eduka, Akiko; Kanazawa, Noriyoshi; Uchiyama, Shiori; Tani, Rie; Kawana, Kennichi; Ohtani, Setsuya; Nagase, Hajime

    2015-05-14

    To evaluate the effectiveness of barium impaction therapy for patients with colonic diverticular bleeding. We reviewed the clinical charts of patients in whom therapeutic barium enema was performed for the control of diverticular bleeding between August 2010 and March 2012 at Yokohama Rosai Hospital. Twenty patients were included in the review, consisting of 14 men and 6 women. The median age of the patients was 73.5 years. The duration of the follow-up period ranged from 1 to 19 mo (median: 9.8 mo). Among the 20 patients were 11 patients who required the procedure for re-bleeding during hospitalization, 6 patients who required it for re-bleeding that developed after the patient left the hospital, and 3 patients who required the procedure for the prevention of re-bleeding. Barium (concentration: 150 w%/v%) was administered per the rectum, and the leading edge of the contrast medium was followed up to the cecum by fluoroscopy. After confirmation that the ascending colon and cecum were filled with barium, the enema tube was withdrawn, and the patient's position was changed every 20 min for 3 h. Twelve patients remained free of re-bleeding during the follow-up period (range: 1-19 mo) after the therapeutic barium enema, including 9 men and 3 women with a median age of 72.0 years. Re-bleeding occurred in 8 patients including 5 men and 3 women with a median age of 68.5 years: 4 developed early re-bleeding, defined as re-bleeding that occurs within one week after the procedure, and the remaining 4 developed late re-bleeding. The DFI (disease-free interval) decreased 0.4 for 12 mo. Only one patient developed a complication from therapeutic barium enema (colonic perforation). Therapeutic barium enema is effective for the control of diverticular hemorrhage in cases where the active bleeding site cannot be identified by colonoscopy.

  12. FATTY ACID STABLE ISOTOPE INDICATORS OF MICROBIAL CARBON SOURCE IN TROPICAL SOILS

    Science.gov (United States)

    The soil microbial community plays an important role in tropical ecosystem functioning because of its importance in the soil organic matter (SOM) cycle. We have measured the stable carbon isotopic ratio (delta13C) of individual phospholipid fatty acids (PLFAs) in a variety of tr...

  13. Salt-embedded carbon nanodots as a UV and thermal stable fluorophore for light-emitting diodes

    International Nuclear Information System (INIS)

    Kim, Tak H.; Wang, Fu; McCormick, Paul; Wang, Lianzhou; Brown, Chris; Li, Qin

    2014-01-01

    UV and thermal stable, photoluminescent carbon dots (CDs) prepared by embedding CDs in ionic salt crystals such as NaCl, KCl, KBr are demonstrated. The salt crystal embedding matrix does not interfere with CDs strong emission, and provides effective protection to CDs from the environment. The degradation of 20% of the initial luminescence intensity of salt-encapsulated CDs (S-CDs) is 15 times slower under UV and 6 times slower under heat compared to that of CDs in silica matrix. We also demonstrate that the S-CDs can be applied as a color-converting phosphor for typical GaN UV light emitting diodes (LEDs) with significant improvements in stability as well as processability. - Highlights: • Carbon dots can be uniformly embedded in ionic salt crystals via crystallization. • Salt crystals provide oxygen-tight matrices for protecting carbon dots from degradations. • Salt-embedded carbon dots can be applied as a stable color-converting phosphor in LEDs

  14. Salt-embedded carbon nanodots as a UV and thermal stable fluorophore for light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tak H. [Queensland Micro- and Nano-Technology Centre, Griffith University, Nathan, QLD 4111 (Australia); Environmental Engineering, Griffith University, QLD 4111 (Australia); Wang, Fu [Institute of Physiology, University of Freiburg, Hermann-Herder-Street 7, 79104 Freiburg (Germany); McCormick, Paul [School of Mechanical and Chemical Engineering, The University of Western Australia, WA 2009 (Australia); Wang, Lianzhou [School of Chemical Engineering, The University of Queensland, QLD 4072 (Australia); Brown, Chris [Queensland Micro- and Nano-Technology Centre, Griffith University, Nathan, QLD 4111 (Australia); Li, Qin, E-mail: qin.li@griffith.edu.au [Queensland Micro- and Nano-Technology Centre, Griffith University, Nathan, QLD 4111 (Australia); Environmental Engineering, Griffith University, QLD 4111 (Australia)

    2014-10-15

    UV and thermal stable, photoluminescent carbon dots (CDs) prepared by embedding CDs in ionic salt crystals such as NaCl, KCl, KBr are demonstrated. The salt crystal embedding matrix does not interfere with CDs strong emission, and provides effective protection to CDs from the environment. The degradation of 20% of the initial luminescence intensity of salt-encapsulated CDs (S-CDs) is 15 times slower under UV and 6 times slower under heat compared to that of CDs in silica matrix. We also demonstrate that the S-CDs can be applied as a color-converting phosphor for typical GaN UV light emitting diodes (LEDs) with significant improvements in stability as well as processability. - Highlights: • Carbon dots can be uniformly embedded in ionic salt crystals via crystallization. • Salt crystals provide oxygen-tight matrices for protecting carbon dots from degradations. • Salt-embedded carbon dots can be applied as a stable color-converting phosphor in LEDs.

  15. Culture of microalgae Spirulina platensis with isotope stable Carbon-13

    International Nuclear Information System (INIS)

    Cronemberger, Luiz C.A.; Costa, Vladimir E.

    2017-01-01

    Gastric emptying time abnormalities cause complications that affect the quality of life in humans and scintigraphy is the gold standard for this diagnosis. However its application has restrictions due to the use of the radiopharmaceutical 99m Tc. An alternative to this method is the stable carbon isotope respiratory test. This is a non-radioactive, noninvasive technique with no contraindications. Its application varies according to the substrate used. For evaluation of gastric emptying time one of the substrates that can be used in the respiratory test is Spirulina platensis labeled at 97% carbon atoms with the stable isotope carbon-13 ( 13 C). In Brazil, there is no production of this substrate and its high cost (US$475.00/g, excluding import taxes) makes it difficult to apply the test. Thus, the objective of the work is to cultivate labeled S. platensis at 97% of 13 C for use in the respiratory test for gastric emptying and to establish optimization parameters for the best cost-benefit of this culture. In the cultivation process the microalgae will be kept in a closed sterilized glass volumetric flask, with deionized water and a pure 13 C source. The light (photoperiod 12h light / dark), pH (∼ 9.5) and temperature (30 deg C) will be controlled and after 35-40 days of growth, the cyanobacteria will be lyophilized and ground for the acquisition of a powder that will be analyzed by IRMS and compared to S. platensis, which will be our reference standard

  16. 21 CFR 201.304 - Tannic acid and barium enema preparations.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Tannic acid and barium enema preparations. 201.304... Tannic acid and barium enema preparations. (a) It has become a widespread practice for tannic acid to be added to barium enemas to improve X-ray pictures. Tannic acid is capable of causing diminished liver...

  17. Effects of Barium Concentration on Oropharyngeal Swallow Timing Measures

    OpenAIRE

    Stokely, Shauna L.; Molfenter, Sonja M.; Steele, Catriona M.

    2013-01-01

    Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between “thin” (40 % w/v concentration) and “ultrathin” (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; ...

  18. Removal efficiency of water purifier and adsorbent for iodine, cesium, strontium, barium and zirconium in drinking water.

    Science.gov (United States)

    Sato, Itaru; Kudo, Hiroaki; Tsuda, Shuji

    2011-01-01

    The severe incident of Fukushima Daiichi Nuclear Power Station has caused radioactive contamination of environment including drinking water. Radioactive iodine, cesium, strontium, barium and zirconium are hazardous fission products because of the high yield and/or relatively long half-life. In the present study, 4 pot-type water purifiers and several adsorbents were examined for the removal effects on these elements from drinking water. Iodide, iodate, cesium and barium were removed by all water purifiers with efficiencies about 85%, 40%, 75-90% and higher than 85%, respectively. These efficiencies lasted for 200 l, which is near the recommended limits for use of filter cartridges, without decay. Strontium was removed with initial efficiencies from 70% to 100%, but the efficiencies were slightly decreased by use. Zirconium was removed by two models, but hardly removed by the other models. Synthetic zeolite A4 efficiently removed cesium, strontium and barium, but had no effect on iodine and zirconium. Natural zeolite, mordenite, removed cesium with an efficiency as high as zeolite A4, but the removal efficiencies for strontium and barium were far less than those of zeolite A4. Activated carbon had little removal effects on these elements. In case of radioactive contamination of tap water, water purifiers may be available for convenient decontamination of drinking water in the home.

  19. Barium Depletion in the NSTAR Discharge Cathode After 30,000 Hours of Operation

    Science.gov (United States)

    Polk, James E.; Capece, Angela M.; Mikellides, Ioannis G.; Katz, Ira

    2010-01-01

    Dispenser hollow cathodes rely on a consumable supply of barium released by impregnant materials in the pores of a tungsten matrix to maintain a low work function surface. Examinations of cathode inserts from long duration ion engine tests show deposits of tungsten at the downstream end that appear to block the flow of barium from the interior. In addition, a numerical model of barium transport in the insert plasma indicates that the barium partial pressure in the insert may exceed the equilibrium vapor pressure of the dominant barium-producing reaction, and it was postulated previously that this would suppress barium loss in the upstream part of the insert. New measurements of the depth of barium depletion from a cathode insert operated for 30,352 hours reveal that barium loss is confined to a narrow region near the downstream end, confirming this hypothesis.

  20. Evaluation of barium hydroxide treatment efficacy on a dolomitic marble.

    Science.gov (United States)

    Toniolo, L; Colombo, C; Realini, M; Peraio, A; Positano, M

    2001-01-01

    The Arch of Peace, by Luigi Cagnola, is one of the most famous neoclassical monuments in Milan. It has been subjected to conservative intervention in 1998. In the present paper the efficacy of the consolidation by means of barium hydroxide has been evaluated. The stone material showed severe degradation phenomena as: erosion, pulverisation, exfoliation. The analytical data acquired through X-ray diffraction (XRD), infrared spectrophotometry (FTIR) and scanning electron microscopy (SEM-EDX), allowed to compare the conditions of stone before and after the treatment with barium hydroxide. The presence of barium has been put in evidence mainly on the surface as barium sulphate, whereas barium is only sporadically present within the thickness of the decayed material. The treatment was judged not satisfying and its inefficacy is, most probably, due to a not suitable cleaning procedure carried out before the consolidation.

  1. Nanocomposites from Stable Dispersions of Carbon Nanotubes in Polymeric Matrices Using Dispersion Interaction

    Science.gov (United States)

    Wise, Kristopher Eric (Inventor); Park, Cheol (Inventor); Kang, Jin Ho (Inventor); Siochi, Emilie J. (Inventor); Harrison, Joycelyn S. (Inventor)

    2016-01-01

    Stable dispersions of carbon nanotubes (CNTs) in polymeric matrices include CNTs dispersed in a host polymer or copolymer whose monomers have delocalized electron orbitals, so that a dispersion interaction results between the host polymer or copolymer and the CNTs dispersed therein. Nanocomposite products, which are presented in bulk, or when fabricated as a film, fiber, foam, coating, adhesive, paste, or molding, are prepared by standard means from the present stable dispersions of CNTs in polymeric matrices, employing dispersion interactions, as presented hereinabove.

  2. SEPARATION OF BARIUM VALUES FROM URANYL NITRATE SOLUTIONS

    Science.gov (United States)

    Tompkins, E.R.

    1959-02-24

    The separation of radioactive barium values from a uranyl nitrate solution of neutron-irradiated uranium is described. The 10 to 20% uranyl nitrate solution is passed through a flrst column of a cation exchange resin under conditions favoring the adsorption of barium and certain other cations. The loaded resin is first washed with dilute sulfuric acid to remove a portion of the other cations, and then wash with a citric acid solution at pH of 5 to 7 to recover the barium along with a lesser amount of the other cations. The PH of the resulting eluate is adjusted to about 2.3 to 3.5 and diluted prior to passing through a smaller second column of exchange resin. The loaded resin is first washed with a citric acid solution at a pH of 3 to elute undesired cations and then with citric acid solution at a pH of 6 to eluts the barium, which is substantially free of undesired cations.

  3. The stable carbon isotope biogeochemistry of acetate and other dissolved carbon species in deep subseafloor sediments at the northern Cascadia Margin

    Science.gov (United States)

    Heuer, Verena B.; Pohlman, John W.; Torres, Marta E.; Elvert, Marcus; Hinrichs, Kai-Uwe

    2009-01-01

    Ocean drilling has revealed the existence of vast microbial populations in the deep subseafloor, but to date little is known about their metabolic activities. To better understand the biogeochemical processes in the deep biosphere, we investigate the stable carbon isotope chemistry of acetate and other carbon-bearing metabolites in sediment pore-waters. Acetate is a key metabolite in the cycling of carbon in anoxic sediments. Its stable carbon isotopic composition provides information on the metabolic processes dominating acetate turnover in situ. This study reports our findings for a methane-rich site at the northern Cascadia Margin (NE Pacific) where Expedition 311 of the Integrated Ocean Drilling Program (IODP) sampled the upper 190 m of sediment. At Site U1329, δ13C values of acetate span a wide range from −46.0‰ to −11.0‰ vs. VPDB and change systematically with sediment depth. In contrast, δ13C values of both the bulk dissolved organic carbon (DOC) (−21.6 ± 1.3‰ vs. VPDB) and the low-molecular-weight compound lactate (−20.9 ± 1.8‰ vs. VPDB) show little variability. These species are interpreted to represent the carbon isotopic composition of fermentation products. Relative to DOC, acetate is up to 23.1‰ depleted and up to 9.1‰ enriched in 13C. Broadly, 13C-depletions of acetate relative to DOC indicate flux of carbon from acetogenesis into the acetate pool while 13C-enrichments of pore-water acetate relative to DOC suggest consumption of acetate by acetoclastic methanogenesis. Isotopic relationships between acetate and lactate or DOC provide new information on the carbon flow and the presence and activity of specific functional microbial communities in distinct biogeochemical horizons of the sediment. In particular, they suggest that acetogenic CO2-reduction can coexist with methanogenic CO2-reduction, a notion contrary to the hypothesis that hydrogen levels are controlled by the thermodynamically most favorable electron

  4. The diagnostic value of barium enema in acute appendicitis

    International Nuclear Information System (INIS)

    Kim, Yong Ga; Chung, Duck Soo; Kim, Ok Dong

    1986-01-01

    Acute appendicitis is the most common acute surgical condition of the abdomen. When the clinical presentation is atypical, barium enema has proven to be safe and useful in confirming the diagnosis and reducing the negative surgical exploration. However, the performance of barium enema in acute appendicitis has known contraindication primarily because of fear of leakage by perforation of the inflamed appendix. This study using barium enema as a diagnostic aid in acute appendicitis with atypical clinical presentation was performed to further support the previously noted efficacy and safety of this procedure. The results were as followings: 1. In case of acute appendicitis with atypical clinical presentation, the use of barium enema as a diagnostic aid increased the accuracy of diagnosis and decreased the negative surgical exploration. In women between 11 to 50 years old age, especially, it played important role differentiating appendicitis from nonsurgical acute abdomen. 2. The results of the study were 92.31% in sensitivity, 7.69% in false positive, 6.9% in false negative, and 10.26% in negative appendectomy. 3. None of case of leakage of barium by perforation of the inflamed appendix was noted, therefore, barium enema was thought to be safe as a diagnostic aid in acute appendicitis. 4. A simple partial or non filling of appendix without other associated positive finding could not exclude appendicitis, therefore, close clinical observation was necessary. 5. The positive findings of barium enema and their sensitivity were as followings: 1. Non filling of appendix: 90% 2. Partial filling of appendix: 91.7% 3. Displacement or a local impression on terminal ileum: 100%

  5. Prompt striations observed in a barium thermite release at 335 km

    International Nuclear Information System (INIS)

    Simons, D.J.; Pongratz, M.B.; Smith, G.M.; Barasch, G.E.; Fitzgerald, T.J.

    1981-01-01

    Three barium clouds have been released from a single rocket at altitudes of 335, 443, and 535 km. The releases were by means of barium thermite injection. Adding the different cross-field velocity components of the rocket at each of the releases resulted in barium clouds with different kinetic velocity distributions. The barium cloud with the most peaked velocity distribution striated promptly, in good agreement with theoretical predictions based on a kinetic plasma instability. Details of the data analysis and experiment are discussed

  6. Effectiveness of therapeutic barium enema for diverticular hemorrhage

    Science.gov (United States)

    Matsuura, Mizue; Inamori, Masahiko; Nakajima, Atsushi; Komiya, Yasuhiko; Inoh, Yumi; Kawasima, Keigo; Naitoh, Mai; Fujita, Yuji; Eduka, Akiko; Kanazawa, Noriyoshi; Uchiyama, Shiori; Tani, Rie; Kawana, Kennichi; Ohtani, Setsuya; Nagase, Hajime

    2015-01-01

    AIM: To evaluate the effectiveness of barium impaction therapy for patients with colonic diverticular bleeding. METHODS: We reviewed the clinical charts of patients in whom therapeutic barium enema was performed for the control of diverticular bleeding between August 2010 and March 2012 at Yokohama Rosai Hospital. Twenty patients were included in the review, consisting of 14 men and 6 women. The median age of the patients was 73.5 years. The duration of the follow-up period ranged from 1 to 19 mo (median: 9.8 mo). Among the 20 patients were 11 patients who required the procedure for re-bleeding during hospitalization, 6 patients who required it for re-bleeding that developed after the patient left the hospital, and 3 patients who required the procedure for the prevention of re-bleeding. Barium (concentration: 150 w%/v%) was administered per the rectum, and the leading edge of the contrast medium was followed up to the cecum by fluoroscopy. After confirmation that the ascending colon and cecum were filled with barium, the enema tube was withdrawn, and the patient’s position was changed every 20 min for 3 h. RESULTS: Twelve patients remained free of re-bleeding during the follow-up period (range: 1-19 mo) after the therapeutic barium enema, including 9 men and 3 women with a median age of 72.0 years. Re-bleeding occurred in 8 patients including 5 men and 3 women with a median age of 68.5 years: 4 developed early re-bleeding, defined as re-bleeding that occurs within one week after the procedure, and the remaining 4 developed late re-bleeding. The DFI (disease-free interval) decreased 0.4 for 12 mo. Only one patient developed a complication from therapeutic barium enema (colonic perforation). CONCLUSION: Therapeutic barium enema is effective for the control of diverticular hemorrhage in cases where the active bleeding site cannot be identified by colonoscopy. PMID:25987779

  7. The impact of digital imaging on patient doses during barium studies

    International Nuclear Information System (INIS)

    Broadhead, D.A.; Chapple, C.-L.; Faulkner, K.

    1995-01-01

    Barium studies performed on 10 digital and four non-digital fluoroscopic systems were monitored with dose-area product meters as part of a Regional Patient Dosimetry Audit programme. The data have been collected using a computer to read and reset the dose-area product meter and also to collect patient and examination details. A comparison of dose-area product measurements from digital and non-digital fluoroscopy units on over 10 000 barium studies is presented. The data have been corrected according to patient size. The mean size corrected dose-area product for a barium meal examination was found to be 7.62 Gy cm -2 for a digital set compared with 15.45 Gy cm -2 for a non-digital set with 2462 and 1308 patients included in each measurement series, respectively. Dose-area products were also a factor of approximately two lower for barium enema, barium swallow and barium follow-through examinations performed on digital systems. (author)

  8. Thermal decomposition of barium ferrate(VI): Mechanism and formation of Fe{sup IV} intermediate and nanocrystalline Fe{sub 2}O{sub 3} and ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Machala, Libor, E-mail: libor.machala@upol.cz [Regional Centre of Advanced Technologies and Materials, Department of Experimental Physics, Faculty of Science, Palacký University, Olomouc (Czech Republic); Sharma, Virender K. [Department of Environmental and Occupational Health, School of Public Health, Texas A& M University, 1266 TAMU, College Station, TX 77843 (United States); Kuzmann, Ernö; Homonnay, Zoltán [Institute of Chemistry, Eötvös Loránd University, Budapest (Hungary); Filip, Jan; Kralchevska, Radina P. [Regional Centre of Advanced Technologies and Materials, Department of Experimental Physics, Faculty of Science, Palacký University, Olomouc (Czech Republic)

    2016-05-25

    Simple high-valent iron-oxo species, ferrate(VI) (Fe{sup VI}O{sub 4}{sup 2−}, Fe(VI)) has applications in energy storage, organic synthesis, and water purification. Of the various salts of Fe(VI), barium ferrate(VI) (BaFeO{sub 4}) has also a great potential as a battery material. This paper presents the thermal decomposition of BaFeO{sub 4} in static air and nitrogen atmosphere, monitored by combination of thermal analysis, Mössbauer spectroscopy, X-ray powder diffraction, and electron-microscopic techniques. The formation of Fe{sup IV} species in the form of BaFeO{sub 3} was found to be the primary decomposition product of BaFeO{sub 4} at temperature around 190 °C under both studied atmospheres. BaFeO{sub 3} was unstable in air reacting with CO{sub 2} to form barium carbonate and speromagnetic amorphous iron(III) oxide nanoparticles (<5 nm). Above 600 °C, a solid state reaction between BaCO{sub 3} and Fe{sub 2}O{sub 3} occurred, leading to the formation of barium ferrite nanoparticles, BaFe{sub 2}O{sub 4} (20–100 nm). - Highlights: • We explained the mechanism of thermal decomposition of barium ferrate(VI). • We confirmed the formation of Fe(IV) intermediate phase during the decomposition. • The mechanism of the decomposition is influenced by a presence of carbon dioxide.

  9. Highly selective and stable carbon dioxide uptake in polyindole-derived microporous carbon materials.

    Science.gov (United States)

    Saleh, Muhammad; Tiwari, Jitendra N; Kemp, K Christain; Yousuf, Muhammad; Kim, Kwang S

    2013-05-21

    Adsorption with solid sorbents is considered to be one of the most promising methods for the capture of carbon dioxide (CO₂) from power plant flue gases. In this study, microporous carbon materials used for CO₂ capture were synthesized by the chemical activation of polyindole nanofibers (PIF) at temperatures from 500 to 800 °C using KOH, which resulted in nitrogen (N)-doped carbon materials. The N-doped carbon materials were found to be microporous with an optimal adsorption pore size for CO₂ of 0.6 nm and a maximum (Brunauer-Emmett-Teller) BET surface area of 1185 m(2) g(-1). The PIF activated at 600 °C (PIF6) has a surface area of 527 m(2) g(-1) and a maximum CO₂ storage capacity of 3.2 mmol g(-1) at 25 °C and 1 bar. This high CO₂ uptake is attributed to its highly microporous character and optimum N content. Additionally, PIF6 material displays a high CO₂ uptake at low pressure (1.81 mmol g(-1) at 0.2 bar and 25 °C), which is the best low pressure CO₂ uptake reported for carbon-based materials. The adsorption capacity of this material remained remarkably stable even after 10 cycles. The isosteric heat of adsorption was calculated to be in the range of 42.7-24.1 kJ mol(-1). Besides the excellent CO₂ uptake and stability, PIF6 also exhibits high selectivity values for CO₂ over N₂, CH₄, and H₂ of 58.9, 12.3, and 101.1 at 25 °C, respectively, and these values are significantly higher than reported values.

  10. Exposure to low-dose barium by drinking water causes hearing loss in mice.

    Science.gov (United States)

    Ohgami, Nobutaka; Hori, Sohjiro; Ohgami, Kyoko; Tamura, Haruka; Tsuzuki, Toyonori; Ohnuma, Shoko; Kato, Masashi

    2012-10-01

    We continuously ingest barium as a general element by drinking water and foods in our daily life. Exposure to high-dose barium (>100mg/kg/day) has been shown to cause physiological impairments. Direct administration of barium to inner ears by vascular perfusion has been shown to cause physiological impairments in inner ears. However, the toxic influence of oral exposure to low-dose barium on hearing levels has not been clarified in vivo. We analyzed the toxic influence of oral exposure to low-dose barium on hearing levels and inner ears in mice. We orally administered barium at low doses of 0.14 and 1.4 mg/kg/day to wild-type ICR mice by drinking water. The doses are equivalent to and 10-fold higher than the limit level (0.7 mg/l) of WHO health-based guidelines for drinking water, respectively. After 2-week exposure, hearing levels were measured by auditory brain stem responses and inner ears were morphologically analyzed. After 2-month exposure, tissue distribution of barium was measured by inductively coupled plasma mass spectrometry. Low-dose barium in drinking water caused severe hearing loss in mice. Inner ears including inner and outer hair cells, stria vascularis and spiral ganglion neurons showed severe degeneration. The Barium-administered group showed significantly higher levels of barium in inner ears than those in the control group, while barium levels in bone did not show a significant difference between the two groups. Barium levels in other tissues including the cerebrum, cerebellum, heart, liver and kidney were undetectably low in both groups. Our results demonstrate for the first time that low-dose barium administered by drinking water specifically distributes to inner ears resulting in severe ototoxicity with degeneration of inner ears in mice. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Barium Titanate Nanoparticles for Biomarker Applications

    International Nuclear Information System (INIS)

    Matar, O; Hondow, N S; Brydson, R M D; Milne, S J; Brown, A P; Posada, O M; Wälti, C; Saunders, M; Murray, C A

    2015-01-01

    A tetragonal crystal structure is required for barium titanate nanoparticles to exhibit the nonlinear optical effect of second harmonic light generation (SHG) for use as a biomarker when illuminated by a near-infrared source. Here we use synchrotron XRD to elucidate the tetragonal phase of commercially purchased tetragonal, cubic and hydrothermally prepared barium titanate (BaTiO 3 ) nanoparticles by peak fitting with reference patterns. The local phase of individual nanoparticles is determined by STEM electron energy loss spectroscopy (EELS), measuring the core-loss O K-edge and the Ti L 3 -edge energy separation of the t 2g , e g peaks. The results show a change in energy separation between the t 2g and e g peak from the surface and core of the particles, suggesting an intraparticle phase mixture of the barium titanate nanoparticles. HAADF-STEM and bright field TEM-EDX show cellular uptake of the hydrothermally prepared BaTiO 3 nanoparticles, highlighting the potential for application as biomarkers. (paper)

  12. Arctic herbivore diet can be inferred from stable carbon and nitrogen isotopes in C3 plants, faeces and wool

    DEFF Research Database (Denmark)

    Kristensen, Ditte; Kristensen, Erik; Forchhammer, Mads C.

    2011-01-01

    The use of stable isotopes in diet analysis usually relies on the different photosynthetic pathways of C3 and C4 plants, and the resulting difference in carbon isotope signature. In the Arctic, however, plant species are exclusively C3, and carbon isotopes alone are therefore not suitable......% graminoids and up to 20% willows. In conclusion, the diet composition of an arctic herbivore can indeed be inferred from stable isotopes in arctic areas, despite the lack of C4 plants...... for studying arctic herbivore diets. In this study, we examined the potential of both stable carbon and nitrogen isotopes to reconstruct the diet of an arctic herbivore, here the muskox (Ovibos moschatus (Zimmermann, 1780)), in northeast Greenland. The isotope composition of plant communities and functional...

  13. Neutral barium cloud evolution at different altitudes

    International Nuclear Information System (INIS)

    Li Lei; Xu Ronglan

    2002-01-01

    Considering the joint effects of diffusion, collision, oxidation and photoionization, the authors study the evolution of the barium cloud at different altitudes in the space plasma active experiment. The results present the variation of the loss rate, number density distribution and brightness of the barium cloud over the range from 120 to 260 km. This can be divided into oxidation, oxidation plus photoionization and photoionization regions

  14. Fabrication and properties of yttrium doped barium titanate film by RF sputtering

    International Nuclear Information System (INIS)

    Igarashi, H.; Yuasa, M.; Okazaki, K.

    1985-01-01

    Semiconductive barium titanate films were fabricated by RF sputtering on fused quartz, alumina and barium titanate ceramic substrates using barium titanate ceramic with a small amount of yttria as a target. The films on the barium titanate substrates turned blue color and showed a small PTC effect by heat-treating at 1000 0 C in the air after deposition at the substrate temperature of 600 0 C

  15. Freeze cast porous barium titanate for enhanced piezoelectric energy harvesting

    Science.gov (United States)

    Roscow, J. I.; Zhang, Y.; Kraśny, M. J.; Lewis, R. W. C.; Taylor, J.; Bowen, C. R.

    2018-06-01

    Energy harvesting is an important developing technology for a new generation of self-powered sensor networks. This paper demonstrates the significant improvement in the piezoelectric energy harvesting performance of barium titanate by forming highly aligned porosity using freeze casting. Firstly, a finite element model demonstrating the effect of pore morphology and angle with respect to poling field on the poling behaviour of porous ferroelectrics was developed. A second model was then developed to understand the influence of microstructure-property relationships on the poling behaviour of porous freeze cast ferroelectric materials and their resultant piezoelectric and energy harvesting properties. To compare with model predictions, porous barium titanate was fabricated using freeze casting to form highly aligned microstructures with excellent longitudinal piezoelectric strain coefficients, d 33. The freeze cast barium titanate with 45 vol.% porosity had a d 33  =  134.5 pC N‑1 compared to d 33  =  144.5 pC N‑1 for dense barium titanate. The d 33 coefficients of the freeze cast materials were also higher than materials with uniformly distributed spherical porosity due to improved poling of the aligned microstructures, as predicted by the models. Both model and experimental data indicated that introducing porosity provides a large reduction in the permittivity () of barium titanate, which leads to a substantial increase in energy harvesting figure of merit, , with a maximum of 3.79 pm2 N‑1 for barium titanate with 45 vol.% porosity, compared to only 1.40 pm2 N‑1 for dense barium titanate. Dense and porous barium titanate materials were then used to harvest energy from a mechanical excitation by rectification and storage of the piezoelectric charge on a capacitor. The porous barium titanate charged the capacitor to a voltage of 234 mV compared to 96 mV for the dense material, indicating a 2.4-fold increase that was similar to that

  16. Radiation losses in microwave K_u region by conducting pyrrole/barium titanate and barium hexaferrite based nanocomposites

    International Nuclear Information System (INIS)

    Kaur, Talwinder; Kumar, Sachin; Narang, S.B.; Srivastava, A.K.

    2016-01-01

    Nanocomposites of substituted barium hexaferrite and barium titanate embedded in a polymer were synthesized via emulsion polymerization. The study was performed by using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, electron spin resonance spectroscopy, a vibrating sample magnetometer and a vector network analyzer. It is found that maximum radiation loss occur at 16.09 GHz (−14.23 dB) frequency owing to the combined effect of conducting polymer, suitable dielectric and magnetic material. This suggests that prepared material is suitable for radiation losses. Micro structural study reveals the presence of all the phases of the compounds comprises composite. Benzene ring absorption band (at 1183 cm"−"1) in FT-IR spectra illustrates the presence of polymer. Surface morphology reveals the presence of array of particles encapsulated by the polymer. - Highlights: • Composites having polymer, barium titanate and hexaferrite have been successfully prepared. • Effective radiation absorption and losses have been achieved. • Magnetic properties have made an impact on shielding effectiveness.

  17. Carbon Stable Isotope Values in Plankton and Mussels Reflect Changes in Carbonate Chemistry Associated with Nutrient Enhanced Net Production

    Science.gov (United States)

    Coastal ecosystems are inherently complex and potentially adaptive as they respond to changes in nutrient loads and climate. We documented the role that carbon stable isotope (δ13C) measurements could play in understanding that adaptation with a series of three Ecostat (i.e...

  18. An Ocean Sediment Core-Top Calibration of Foraminiferal (Cibicides) Stable Carbon Isotope Ratios

    Science.gov (United States)

    Schmittner, A.; Mix, A. C.; Lisiecki, L. E.; Peterson, C.; Mackensen, A.; Cartapanis, O. A.

    2015-12-01

    Stable carbon isotope ratios (δ13C) measured on calcium carbonate shells of benthic foraminifera (cibicides) from late Holocene sediments (δ13CCib) are compiled and compared with newly updated datasets of contemporary water-column δ13C observations of dissolved inorganic carbon (δ13CDIC) as the initial core-top calibration of the international Ocean Circulation and CarbonCycling (OC3) project. Using selection criteria based on the spatial distance between samples we find high correlation between δ13CCib and natural (pre-industrial) δ13CDIC, confirming earlier work. However, our analysis reveals systematic differences such as higher (lower) δ13CCib values in the Atlantic (Indian and Pacific) oceans. Regression analyses are impacted by anthropogenic carbon and suggest significant carbonate ion, temperature, and pressure effects, consistent with lab experiments with planktonic foraminifera and theory. The estimated standard error of core-top sediment data is generally σ ~= 0.25 ‰, whereas modern foram data from the South Atlantic indicate larger errors (σ ~= 0.4 ‰).

  19. Fabry-Perot measurements of barium temperature in fluorescent lamps

    International Nuclear Information System (INIS)

    Hadrath, S; Garner, R

    2010-01-01

    A scanning Fabry-Perot interferometer (FPI) is used to determine the temperature of barium atoms that are liberated from the electrodes of fluorescent lamps during their steady-state operation. Barium, a constituent of the work function lowering emitter material that is placed on the tungsten coil that forms the electrode, is liberated primarily by evaporation from the hot (∼1300 K) thermionic electrode. However, there may be situations or modes of operation in which barium is, in addition, sputtered, a condition which may lead to increased end-darkening, shortened life and increased mercury consumption in the lamp. Using the FPI diagnostic, the occurrence of sputtering is inferred when barium temperatures are much greater than the electrode temperature. The FPI diagnostic senses resonance radiation (λ = 553 nm) emitted by barium atoms excited in the low pressure discharge environment, and infers temperature from the Doppler broadened linewidth. The diagnostic has proven to be successful in a number of situations. Measurements have been made on rare gas discharges and on Hg-argon discharges for different discharge currents, gas pressures and auxiliary coil currents. Measurements are phase resolved for ac-driven discharges.

  20. Effect of Nb on barium titanate prepared from citrate solutions

    Directory of Open Access Journals (Sweden)

    Stojanović Biljana D.

    2002-01-01

    Full Text Available The influence of the addition of dopants on the microstructure development and electrical properties of BaTiO3 doped with 0.2, 0.4, 0.6, 0.8 mol% of Nb and 0.01 mol% of Mn based compounds was studied. Doped barium titanate was prepared using the polymeric precursor method from citrate solutions. The powders calcined at 700°C for 4 hours were analysed by infrared (IR spectroscopy to verify the presence of carbonates, and by X-ray diffraction (XRD for phase formation. The phase composition, microstructure and dielectric properties show a strong dependence on the amount of added niobium.

  1. Influence of barium substitution on bioactivity, thermal and physico-mechanical properties of bioactive glass.

    Science.gov (United States)

    Arepalli, Sampath Kumar; Tripathi, Himanshu; Vyas, Vikash Kumar; Jain, Shubham; Suman, Shyam Kumar; Pyare, Ram; Singh, S P

    2015-04-01

    Barium with low concentration in the glasses acts as a muscle stimulant and is found in human teeth. We have made a primary study by substituting barium in the bioactive glass. The chemical composition containing (46.1-X) SiO2--24.3 Na2O-26.9 CaO-2.6 P2O5, where X=0, 0.4, 0.8, 1.2 and 1.6mol% of BaO was chosen and melted in an electric furnace at 1400±5°C. The glasses were characterized to determine their use in biomedical applications. The nucleation and crystallization regimes were determined by DTA and the controlled crystallization was carried out by suitable heat treatment. The crystalline phase formed was identified by using XRD technique. Bioactivity of these glasses was assessed by immersion in simulated body fluid (SBF) for various time periods. The formation of hydroxy carbonate apatite (HCA) layer was identified by FTIR spectrometry, scanning electron microscope (SEM) and XRD which showed the presence of HCA as the main phase in all tested bioactive glass samples. Flexural strength and densities of bioactive glasses have been measured and found to increase with increasing the barium content. The human blood compatibility of the samples was evaluated and found to be pertinent. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Barium sulfate suspension as a negative oral contrast agent for MR imaging

    International Nuclear Information System (INIS)

    Li, K.C.P.; Tart, R.P.; Fitzsimmons, J.R.; Storm, B.; Mao, J.

    1989-01-01

    Proton spectroscopy with linewidth measurements and MR imaging were performed on various commercially available barium sulfate suspensions as well as inorganic sulfates and barium salts. Approximately 500 mL of 20%, 40%, 60%, and 70% wt/wt single-contrast oral barium sulfate suspensions were administered to four normal volunteers, and MR imaging was performed with both a 1.5-T and a 0.15-T MR imager. As much as 80% of the small bowel and the entire colon were well visualized with the 60% or 70% wt/wt single-contrast barium sulfate suspensions. The authors conclude that barium sulfate suspensions are useful as oral MR contrast agents

  3. Simplified assessment of segmental gastrointestinal transit time with orally small amount of barium

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Weitang; Zhang, Zhiyong; Liu, Jinbo; Li, Zhen; Song, Junmin; Wu, Changcai [Department of Colorectal Surgery, The First Affiliated Hospital and Institute of Clinical Medicine, Zhengzhou University, 450052 Zhengzhou (China); Wang, Guixian, E-mail: guixianwang@hotmail.com [Department of Colorectal Surgery, The First Affiliated Hospital and Institute of Clinical Medicine, Zhengzhou University, 450052 Zhengzhou (China)

    2012-09-15

    Objective: To determine the effectiveness and advantage of small amount of barium in the measurement of gastrointestinal transmission function in comparison with radio-opaque pallets. Methods: Protocal 1: 8 healthy volunteers (male 6, female 2) with average age 40 ± 6.1 were subjected to the examination of radio-opaque pellets and small amount of barium with the interval of 1 week. Protocol 2: 30 healthy volunteers in group 1 (male 8, female 22) with average age 42.5 ± 8.1 and 50 patients with chronic functional constipation in group 2 (male 11, female 39) with average age 45.7 ± 7.8 were subjected to the small amount of barium examination. The small amount of barium was made by 30 g barium dissolved in 200 ml breakfast. After taking breakfast which contains barium, objectives were followed with abdominal X-ray at 4, 8, 12, 24, 48, 72, 96 h until the barium was evacuated totally. Results: Small amount of barium presented actual chyme or stool transit. The transit time of radio-opaque pallets through the whole gastrointestinal tract was significantly shorter than that of barium (37 ± 8 h vs. 47 ± 10 h, P < 0.05) in healthy people. The transit times of barium in constipation patients were markedly prolonged in colon (61.1 ± 22 vs. 37.3 ± 11, P < 0.01) and rectum (10.8 ± 3.7 vs. 2.3 ± 0.8 h, P < 0.01) compared with unconstipated volunteers. Transit times in individual gastrointestinal segments were also recorded by using small amount of barium, which allowed identifying the subtypes of constipation. Conclusion: The small amount barium examination is a convenient and low cost method to provide the most useful and reliable information on the transmission function of different gastrointestinal segments and able to classify the subtypes of slow transit constipation.

  4. Simplified assessment of segmental gastrointestinal transit time with orally small amount of barium

    International Nuclear Information System (INIS)

    Yuan, Weitang; Zhang, Zhiyong; Liu, Jinbo; Li, Zhen; Song, Junmin; Wu, Changcai; Wang, Guixian

    2012-01-01

    Objective: To determine the effectiveness and advantage of small amount of barium in the measurement of gastrointestinal transmission function in comparison with radio-opaque pallets. Methods: Protocal 1: 8 healthy volunteers (male 6, female 2) with average age 40 ± 6.1 were subjected to the examination of radio-opaque pellets and small amount of barium with the interval of 1 week. Protocol 2: 30 healthy volunteers in group 1 (male 8, female 22) with average age 42.5 ± 8.1 and 50 patients with chronic functional constipation in group 2 (male 11, female 39) with average age 45.7 ± 7.8 were subjected to the small amount of barium examination. The small amount of barium was made by 30 g barium dissolved in 200 ml breakfast. After taking breakfast which contains barium, objectives were followed with abdominal X-ray at 4, 8, 12, 24, 48, 72, 96 h until the barium was evacuated totally. Results: Small amount of barium presented actual chyme or stool transit. The transit time of radio-opaque pallets through the whole gastrointestinal tract was significantly shorter than that of barium (37 ± 8 h vs. 47 ± 10 h, P < 0.05) in healthy people. The transit times of barium in constipation patients were markedly prolonged in colon (61.1 ± 22 vs. 37.3 ± 11, P < 0.01) and rectum (10.8 ± 3.7 vs. 2.3 ± 0.8 h, P < 0.01) compared with unconstipated volunteers. Transit times in individual gastrointestinal segments were also recorded by using small amount of barium, which allowed identifying the subtypes of constipation. Conclusion: The small amount barium examination is a convenient and low cost method to provide the most useful and reliable information on the transmission function of different gastrointestinal segments and able to classify the subtypes of slow transit constipation

  5. Comparison of pressure between barium reduction and air reduction of the intussusception in children

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung Hwan; Park, Sang Gyu; Park, Choong Ki; Yoon, Jong Sup [Hallym University College of Medicine, Seoul (Korea, Republic of)

    1989-08-15

    There are many method of treatment of the intussusception in children, including surgery, barium reduction, air reduction, and saline enema under ultrasonographic monitoring. Among them, barium reduction and air reduction have been used widely as nonsurgical method of treatment in radiologic department. During barium reduction, the bottle filled with barium solution must not be elevated over a 3 feet from the operating table. In air reduction, diagnostic pressure is about 60 mmHg and pressure during reduction usually is maintained between 90 mmHg and 130 mmHg. The authors have studied about pressure difference of barium solution by changing height of the bottle filled with barium solution, and have compared with pressure in air reduction. The results are as follows; 1. Pressure of 20 w/v % barium solution at the 60 cm height is 44.4 mmHg, and 69.6 mmHg at the 90 cm height. 2. Pressure of 40 w/v % barium solution at the 60 cm height is 51.4 mmHg, and 80.1 mmHg at the 90 cm height. 3. Pressure of 40 w/v % barium solution at the 90cm height is much lower than the pressure maintained during air reduction, and this difference in pressure may be one of the causes of low reduction rate in barium reduction then air reduction. 4. The pressure gradient per 10 cm height is about 8.45 mmHg in 20 w/v % barium solution, about 9.21 mmHg in 30 w/v % barium solution, and about 9.72 mmHg 40 w/v % barium solution. 5. Intraluminal pressure difference between the barium reduction and the air reduction is probably of the major causes of rapid diagnosis and high reduction rate in the air reduction.

  6. Comparison of pressure between barium reduction and air reduction of the intussusception in children

    International Nuclear Information System (INIS)

    Lee, Kyung Hwan; Park, Sang Gyu; Park, Choong Ki; Yoon, Jong Sup

    1989-01-01

    There are many method of treatment of the intussusception in children, including surgery, barium reduction, air reduction, and saline enema under ultrasonographic monitoring. Among them, barium reduction and air reduction have been used widely as nonsurgical method of treatment in radiologic department. During barium reduction, the bottle filled with barium solution must not be elevated over a 3 feet from the operating table. In air reduction, diagnostic pressure is about 60 mmHg and pressure during reduction usually is maintained between 90 mmHg and 130 mmHg. The authors have studied about pressure difference of barium solution by changing height of the bottle filled with barium solution, and have compared with pressure in air reduction. The results are as follows; 1. Pressure of 20 w/v % barium solution at the 60 cm height is 44.4 mmHg, and 69.6 mmHg at the 90 cm height. 2. Pressure of 40 w/v % barium solution at the 60 cm height is 51.4 mmHg, and 80.1 mmHg at the 90 cm height. 3. Pressure of 40 w/v % barium solution at the 90cm height is much lower than the pressure maintained during air reduction, and this difference in pressure may be one of the causes of low reduction rate in barium reduction then air reduction. 4. The pressure gradient per 10 cm height is about 8.45 mmHg in 20 w/v % barium solution, about 9.21 mmHg in 30 w/v % barium solution, and about 9.72 mmHg 40 w/v % barium solution. 5. Intraluminal pressure difference between the barium reduction and the air reduction is probably of the major causes of rapid diagnosis and high reduction rate in the air reduction

  7. Barium ion beam. Annual progress report

    International Nuclear Information System (INIS)

    Lazar, N.; Dandl, R.; Rynn, N.; Wickham, M.

    1985-01-01

    The barium ion beam Zeeman diagnostic is an in situ nonperturbing diagnostic designed to measure both the plasma electric and magnetic fields in devices such as STM and EBT. The diagnostic satisfies the requirements of high precision, spatial resolution and nonperturbation of the plasma. The technique uses resonance absorption of light from a single moded laser in a beam of energetic barium ions to measure the Zeeman effect in the absorption spectrum (to measure changes in the magnetic field) and to observe the changes in beam velocity by the Doppler shift of the absorption lines

  8. Application of carbon and oxygen stable isotopes to the study of Brazilian precambrian

    International Nuclear Information System (INIS)

    Torquato, J.R.F.

    1980-01-01

    Samples of carbonated rocks of precambrian age are studied. The stable carbon and oxygen isotopes are applied to the study of terrestrial materials considering the variations of some element isotopic composition in function of the environment of sedimentation. The isotopic analysis was done using mass spectrometers. The analytical results and the description of region geology of the site of each sample are presented. The isotopic data are interpreted aiming to the environment of sedimentation. New techniques for better improvement of carbon and oxygen ratios, are proposed, such as: to use the analysis of surface trend and the isotopic logging in mapping of surface and subsurface. A new method for approximated determination of the ages of precambrian carbonated rocks, considering the limitations of their new technique, is also presented. (M.C.K.) [pt

  9. Differential utilization of allochthonous and autochthonous carbon by aquatic insects of two shrub-steppe desert spring-streams: A stable carbon isotope analysis and critique of the method

    Energy Technology Data Exchange (ETDEWEB)

    Mize, A. L. [Old Dominion Univ., Norfolk, VA (United States)

    1993-06-01

    The purpose of this study is to assess whether the carbon supporting stream food webs comes principally from terrestrial sources or is produced within the stream. Lacking data to resolve the allochthonous/autochthonous issue with any finality, stream ecologists have alternately postulated that stream carbon was principally autochthonous or principally allochthonous. Others argued that autochthonous and allochthonous carbon resources cannot be separated and that the allochthonous/autochthonous dependence issue is unresolvable. Many investigators have seized upon stable carbon isotopes technology as the tool to resolve the controversy. Unfortunately most investigators have conceded that the results are rarely quantitative and that the qualitative relationships are ambiguous. This study points out the fallacies of trying to conjure single isotopic values for either allochthonous or autochthonous carbon. It suggests that stable carbon isotope technology is not reliable in establishing specific consumer/food source relations and that it is not suitable for assessing allochthonous/autochthonous carbon dependence in freshwater streams.

  10. Characterization of Barium Borate Frameworks Using Raman Spectroscopy.

    Science.gov (United States)

    Gharavi-Naeini, Jafar; Yoo, Kyung W; Stump, Nathan A

    2018-04-01

    Systematic micro-Raman scattering investigations have been carried out on Sm +2 doped 2(BaO)-n(B 2 O 3 ) matrices for n = 4, 5, 8, and 2(BaO)-(Na 2 O)-9(B 2 O 3 ) using the 364 nm excitation of an Ar + laser. The Raman results have been compared with the known structures of barium tetraborate, barium pentaborate, barium octaborate, and barium sodium nonaborate. An excellent correlation has been found between the BO 4 /BO 3 composition ratios for each product and intensity ratios of the designated BO 4 and BO 3 Raman peaks. Furthermore, the Raman frequencies of both BO 4 and BO 3 groups undergo a systematic blueshift as n increases from four to nine. The shift results from a decrease of the B-O bond lengths for both BO 4 and BO 3 groups as the samples transition from the tetraborate to nonaborate structures. Linear relations (with negative slopes) have been determined between the measured Raman frequencies and B-O bond lengths in the frameworks.

  11. 40 CFR 721.10010 - Barium manganese oxide (BaMnO3).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Barium manganese oxide (BaMnO3). 721... Substances § 721.10010 Barium manganese oxide (BaMnO3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as barium manganese oxide (BaMnO3) (PMN P-00...

  12. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  13. Characteristics of stable carbon isotopic composition of shale gas

    Directory of Open Access Journals (Sweden)

    Zhenya Qu

    2016-04-01

    Full Text Available A type Ⅱ kerogen with low thermal maturity was adopted to perform hydrocarbon generation pyrolysis experiments in a vacuum (Micro-Scale Sealed Vessel system at the heating rates of 2 °C/h and 20 °C/h. The stable carbon isotopic compositions of gas hydrocarbons were measured to investigate their evolving characteristics and the possible reasons for isotope reversal. The δ13C values of methane became more negative with the increasing pyrolysis temperatures until it reached the lightest point, after which they became more positive. Meanwhile, the δ13C values of ethane and propane showed a positive trend with elevating pyrolysis temperatures. The carbon isotopic compositions of shale gasses were mainly determined by the type of parent organic matter, thermal evolutionary extent, and gas migration in shale systems. Our experiments and study proved that the isotope reversal shouldn't occur in a pure thermogenic gas reservoir, it must be involved with some other geochemical process/es; although mechanisms responsible for the reversal are still vague. Carbon isotopic composition of the Fayetteville and Barnett shale gas demonstrated that the isotope reversal was likely involved with water–gas reaction and Fischer-Tropsch synthesis during its generation.

  14. Plutonium oxides and uranium and plutonium mixed oxides. Carbon determination

    International Nuclear Information System (INIS)

    Anon.

    Determination of carbon in plutonium oxides and uranium plutonium mixed oxides, suitable for a carbon content between 20 to 3000 ppm. The sample is roasted in oxygen at 1200 0 C, the carbon dioxide produced by combustion is neutralized by barium hydroxide generated automatically by coulometry [fr

  15. A promising lightweight multicomponent microwave absorber based on doped barium hexaferrite/calcium titanate/multiwalled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Afghahi, Seyyed Salman Seyyed [Imam Hossein University, Department of Materials Science and Engineering (Iran, Islamic Republic of); Jafarian, Mojtaba, E-mail: m.jafarian@srbiau.ac.ir [Islamic Azad University, Young Researchers and Elite Club, Science and Research Branch (Iran, Islamic Republic of); Atassi, Yomen [Higher Institute for Applied Sciences and Technology, Department of Applied Physics (Syrian Arab Republic)

    2016-07-15

    We present the design of a microwave absorber in the X band based on ternary nanocomposite of doped barium hexaferrite (Ba-M)/calcium titanate (CTO)/multiwall carbon nanotubes (MWCNTs) in epoxy matrix. The hydrothermal method has been used to synthesize Ba-M and CTO nanopowder. The phase identification has been investigated using XRD patterns. Scanning electron microscope, transmission electron microscope, vibrating sample magnetometer, and vector network analyzer are used to analyze the morphology of the different components and the magnetic, electromagnetic, and microwave absorption properties of the final composite absorbers, respectively. As far as we know, the design of this type of multicomponent microwave absorber has not been investigated before. The results reveal that the combination of these three components with their different loss mechanisms has a synergistic effect that enhances the attenuation properties of the final composite. The absorber of only 2.5-mm thickness and 35 wt% of loading ratio exhibits a minimum reflection loss of −43 dB at 10.2 GHz with a bandwidth of 3.6 GHz, while the corresponding absorber based on pure (Ba-M) shows a minimum reflection loss of −34 dB at 9.8 GHz with a bandwidth of 0.256 GHz and a thickness of 4 mm.Graphical Abstract.

  16. Radiation losses in microwave K{sub u} region by conducting pyrrole/barium titanate and barium hexaferrite based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Talwinder [Department of Physics, Lovely Professional University, Phagwara 144411 (India); Kumar, Sachin [Department of Chemistry, Guru Nanak Dev University, Amritsar 143005 (India); Narang, S.B. [Department of Electronics Technology, Guru Nanak Dev University, Amritsar 143005 (India); Srivastava, A.K., E-mail: srivastava_phy@yahoo.co.in [Department of Physics, Lovely Professional University, Phagwara 144411 (India)

    2016-12-15

    Nanocomposites of substituted barium hexaferrite and barium titanate embedded in a polymer were synthesized via emulsion polymerization. The study was performed by using X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, electron spin resonance spectroscopy, a vibrating sample magnetometer and a vector network analyzer. It is found that maximum radiation loss occur at 16.09 GHz (−14.23 dB) frequency owing to the combined effect of conducting polymer, suitable dielectric and magnetic material. This suggests that prepared material is suitable for radiation losses. Micro structural study reveals the presence of all the phases of the compounds comprises composite. Benzene ring absorption band (at 1183 cm{sup −1}) in FT-IR spectra illustrates the presence of polymer. Surface morphology reveals the presence of array of particles encapsulated by the polymer. - Highlights: • Composites having polymer, barium titanate and hexaferrite have been successfully prepared. • Effective radiation absorption and losses have been achieved. • Magnetic properties have made an impact on shielding effectiveness.

  17. Preparation of porous nano barium ferrite and its adsorption properties on uranium

    International Nuclear Information System (INIS)

    Xiong Guoxuan; Huang Haiqing; Zhang Zhibin

    2012-01-01

    The porous nano barium ferrite was made of Fe(NO 3 ) 3 and Ba(NO 3 ) 2 as raw materials, CTAB as surfactant by method of sol-gel and self-propagating combustion. The composition, morphology and magnetic properties of nano-rod barium ferrite were characterized by XRD, SEM and vibrating sample magnetometer. The adsorption properties of porous nano barium ferrite on uranium were studied with static adsorption and the effects of pH, adsorption temperature and oscillation time on adsorption properties were discussed. The results indicate that the average particle size of porous nano barium ferrite is 45-65 nm, the saturation magnetization and coercivity are 62.83 emu/g and 5481.0 Oe, respectively. Under the condition of the porous nano barium ferrite amount of 0.02 g, pH of 6, adsorption temperature of 25℃ and oscillation time of 30 min, the adsorption capacity of uranium on the porous nano barium ferrite reaches 921 μg/g. (authors)

  18. A review of the health impacts of barium from natural and anthropogenic exposure.

    Science.gov (United States)

    Kravchenko, Julia; Darrah, Thomas H; Miller, Richard K; Lyerly, H Kim; Vengosh, Avner

    2014-08-01

    There is an increasing public awareness of the relatively new and expanded industrial barium uses which are potential sources of human exposure (e.g., a shale gas development that causes an increased awareness of environmental exposures to barium). However, absorption of barium in exposed humans and a full spectrum of its health effects, especially among chronically exposed to moderate and low doses of barium populations, remain unclear. We suggest a systematic literature review (from 1875 to 2014) on environmental distribution of barium, its bioaccumulation, and potential and proven health impacts (in animal models and humans) to provide the information that can be used for optimization of future experimental and epidemiological studies and developing of mitigative and preventive strategies to minimize negative health effects in exposed populations. The potential health effects of barium exposure are largely based on animal studies, while epidemiological data for humans, specifically for chronic low-level exposures, are sparse. The reported health effects include cardiovascular and kidney diseases, metabolic, neurological, and mental disorders. Age, race, dietary patterns, behavioral risks (e.g., smoking), use of medications (those that interfere with absorbed barium in human organism), and specific physiological status (e.g., pregnancy) can modify barium effects on human health. Identifying, evaluating, and predicting the health effects of chronic low-level and moderate-level barium exposures in humans is challenging: Future research is needed to develop an understanding of barium bioaccumulation in order to mitigate its potential health impacts in various exposured populations. Further, while occupationally exposed at-risk populations exist, it is also important to identify potentially vulnerable subgroups among non-occupationally exposed populations (e.g., elderly, pregnant women, children) who are at higher risk of barium exposure from drinking water and food.

  19. The diagnosis of gastro-esophageal reflux disease cannot be made with barium esophagograms.

    Science.gov (United States)

    Saleh, C M G; Smout, A J P M; Bredenoord, A J

    2015-02-01

    For over 50 years, barium studies have been used to diagnose gastro-esophageal reflux disease (GERD), but the value of this test is controversial. Our study aimed to determine if barium esophagograms can be used to diagnose GERD. Barium esophagograms and pH-impedance measurement were performed in 20 subjects with reflux symptoms. pH-impedance measurements were used as gold standard for the diagnosis of GERD. Gastro-esophageal reflux measured with the barium study was defined as a positive outcome. 50% of patients presented gastro-esophageal reflux on the barium esophagogram. No significant differences were observed in acid exposure time between subjects with (median: 7.4%; interquartile range, IQR: 8.4%) or without reflux at barium esophagography (median: 5.95%; IQR: 13.05%; p > 0.05). Nor did we find differences in median proximal extent of reflux measured with impedance monitoring between patients with a positive (median: 6.7%; IQR: 1.95%) and negative barium study (median: 7.1%; IQR: 0.68%; p > 0.05). Patients with reflux on barium esophagogram did not have a positive symptom association probability more often than those who did not have reflux at barium esophagography. Lastly, there were no differences in numbers of acid, weakly acidic or total reflux episodes between those with positive or negative barium esophagogram (p > 0.05). No correlations were found between the maximum proximal extent of gastro-esophageal reflux during esophagography and pH-impedance parameters. Presence or absence of gastro-esophageal reflux during barium esophagography does not correlate with incidence or extent of reflux observed during 24-h pH-impedance monitoring and is not of value for the diagnosis of GERD. © 2014 John Wiley & Sons Ltd.

  20. Contrast characteristics of barium preparations and the timing of exposure

    OpenAIRE

    渋谷, 光一; 中桐, 義忠; 東, 義晴; 杉田, 勝彦; 小橋, 高郎; 大倉, 保彦; 丹谷, 延義; 三上, 泰隆; 平木, 祥夫

    1995-01-01

    We studied the relationship between the contrast characteristics of barium suspension and timing of exposure. We poured several kinds of barium preparations on the phantom manufactured by ourselves, and took X-ray pictures continuously by a DSA system. We analyzed each of the characteris-tics of the contrast. The time which was reguired for the contrast to reach the peak (Contrast Peak Time ; CPT) was unrelated with the kind of barium preparations used. It depended on the viscosity of the con...

  1. Production of metal fullerene surface layer from various media in the process of steel carbonization

    Directory of Open Access Journals (Sweden)

    KUZEEV Iskander Rustemovich

    2018-04-01

    Full Text Available Studies devoted to production of metal fullerene layer in steels when introducing carbon from organic and inorganic media were performed. Barium carbonate was used as an inorganic medium and petroleum pitch was used as an organic medium. In order to generate the required amount of fullerenes in the process of steel samples carbonization, optimal temperature mode was found. The higher temperature, absorption and cohesive effects become less important and polymeric carbon structures destruction processes become more important. On the bottom the temperature is limited by petroleum pitch softening temperature and its transition to low-viscous state in order to enhance molecular mobility and improve the possibility of their diffusion to metal surface. Identification of fullerenes in the surface modified layer was carried out following the methods of IR-Fourier spectrometry and high-performance liquid chromatography. It was found out that nanocarbon structures, formed during carbonization in barium carbonate and petroleum pitch mediums, possess different morphology. In the process of metal carbonization from carbonates medium, the main role in fullerenes synthesis is belonged to catalytic effect of surface with generation of endohedral derivatives in the surface layer; but in the process of carbonization from pitch medium fullerenes are formed during crystallization of the latter and crystallization centers are of fullerene type. Based on theoretical data and dataof spectral and chromatographic analysis, optimal conditions of metal fullerene layer formation in barium carbonate and petroleum pitch mediums were determined. Low cohesion of layer, modified in barium carbonate medium, with metal basis was discovered. That was caused by limited carbon diffusion in the volume of α-Fe. According to the detected mechanism of fullerenes formation on steel surface in gaseous medium, fullerenes are formed on catalytic centers – ferrum atoms, forming thin metal

  2. Outcome of barium enema in patients with colorectal symptoms ...

    African Journals Online (AJOL)

    Background: For many years, double contrast barium enema has been an effective way to evaluate the large bowel. With the development of the colonoscope, the role of barium enema has been questioned. However it is still useful in investigating patients with colorectal symptoms especially in the developing world where ...

  3. Application of magnesium hydroxide and barium hydroxide for the ...

    African Journals Online (AJOL)

    Application of magnesium hydroxide and barium hydroxide for the removal of metals and sulphate from mine water. ... equivalent to the Ba(OH)2 dosage. During CO2-dosing, CaCO3 is precipitated to the saturation level of CaCO3. Keywords: Magnesium hydroxide; barium hydroxide; sulphate removal; water treatment ...

  4. 49 CFR 173.182 - Barium azide-50 percent or more water wet.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Barium azide-50 percent or more water wet. 173.182 Section 173.182 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... Class 1 and Class 7 § 173.182 Barium azide—50 percent or more water wet. Barium azide—50 percent or more...

  5. Barium-borate-flyash glasses: As radiation shielding materials

    International Nuclear Information System (INIS)

    Singh, Sukhpal; Kumar, Ashok; Singh, Devinder; Thind, Kulwant Singh; Mudahar, Gurmel S.

    2008-01-01

    The attenuation coefficients of barium-borate-flyash glasses have been measured for γ-ray photon energies of 356, 662, 1173 and 1332 keV using narrow beam transmission geometry. The photon beam was highly collimated and overall scatter acceptance angle was less than 3 o . Our results have an uncertainty of less than 3%. These coefficients were then used to obtain the values of mean free path (mfp), effective atomic number and electron density. Good agreements have been observed between experimental and theoretical values of these parameters. From the studies of the obtained results it is reported here that from the shielding point of view the barium-borate-flyash glasses are better shields to γ-radiations in comparison to the standard radiation shielding concretes and also to the ordinary barium-borate glasses

  6. Selection of a carbon-14 fixation form

    International Nuclear Information System (INIS)

    Scheele, R.D.; Burger, L.L.

    1982-09-01

    This report summarizes work on the selection of a disposal form for carbon-14 produced during the production of nuclear power. Carbon compounds were screened on the basis of solubility, thermal stability, resistance to oxidation, cost and availability, compatibility with the selected disposal matrix, leach resistance when incorporated in concrete, and compatibility with capture technologies. Carbonates are the products of the various technologies presently considered for carbon-14 capture. The alkaline earth carbonates exhibit the greatest thermal stabilities, lowest solubilities, lowest raw material cost, and greatest raw material availabilities. When reactions with cement and its impurities are considered, calcium and strontium carbonates are the only alkaline earth carbonates resistant to hydrolysis and reaction with sulfate. Leaching tests of barium, calcium, lead, potassium, and strontium carbonates in concrete showed calcium carbonate concrete to be slightly superior to the other alkaline earth carbonates, and greatly superior to a soluble carbonate, potassium carbonate, and lead carbonate. None of the additives to the concrete reduced the carbonate leaching. Acidic CO 2 -containing waters were found to greatly increase carbonate leaching from concrete. Sea water was found to leach less carbon from carbonate concretes than either distilled water or Columbia River water, which showed nearly equivalent leaching. Based on our work, calcium, barium, and strontium carbonates in concrete are the most suitable waste forms for carbon-14, with calcium carbonate concrete slightly superior to the others. If the waste form is to be exposed to natural waters, sea water will have the lowest leach rate. 6 figures, 7 tables

  7. Effects of euthanasia method on stable-carbon and stable-nitrogen isotope analysis for an ectothermic vertebrate.

    Science.gov (United States)

    Atwood, Meredith A

    2013-04-30

    Stable isotope analysis is a critical tool for understanding ecological food webs; however, results can be sensitive to sample preparation methods. To limit the possibility of sample contamination, freezing is commonly used to euthanize invertebrates and preserve non-lethal samples from vertebrates. For destructive sampling of vertebrates, more humane euthanasia methods are preferred to freezing and it is essential to evaluate how these euthanasia methods affect stable isotope results. Stable isotope ratios and elemental composition of carbon and nitrogen were used to evaluate whether the euthanasia method compromised the integrity of the sample for analysis. Specifically, the stable isotope and C:N ratios were compared for larval wood frogs (Rana sylvatica  =  Lithobates sylvaticus), an ectothermic vertebrate, that had been euthanized by freezing with four different humane euthanasia methods: CO2, benzocaine, MS-222 (tricaine methanesulfonate), and 70% ethanol. The euthanasia method was not related to the δ(13)C or δ(15)N values and the comparisons revealed no differences between freezing and any of the other treatments. However, there were slight (non-significant) differences in the isotope ratios of benzocaine and CO2 when each was compared with freezing. The elemental composition was altered by the euthanasia method employed. The percentage nitrogen was higher in CO2 treatments than in freezing, and similar (non-significant) trends were seen for ethanol treatments relative to freezing. The resulting C:N ratios were higher for benzocaine treatments than for both CO2 and ethanol. Similar (non-significant) trends suggested that the C:N ratios were also higher for animals euthanized by freezing than for both CO2 and ethanol euthanasia methods. The euthanasia method had a larger effect on elemental composition than stable isotope ratios. The percentage nitrogen and the subsequent C:N ratios were most affected by the CO2 and ethanol euthanasia methods, whereas

  8. BARIUM REDUCTION OF INTUSSUSCEPTION IN INFANCY

    Science.gov (United States)

    Denenholz, Edward J.; Feher, George. S.

    1955-01-01

    Barium enema reduction was used as the initial routine treatment in 29 infants with intussusception. In 22 of them the intussusception was reduced by this means. In three of eight patients operated upon the intussusception was found to be reduced. Four of the remaining five patients had clinical or x-ray evidence of complications before reduction by barium enema was attempted. Twenty-one of the patients, all of whom were observed in private practice, were treated without admission to the hospital. After reduction, these patients were observed closely by the clinician. None of these patients showed clinical or x-ray signs of complications before reduction. Certain clinical and roentgen criteria must be satisfied before it can be concluded that reduction by barium enema is complete. If there are clinical signs of complications with x-ray evidence of small bowel obstruction, only a very cautious attempt at hydrostatic reduction should be made. As the time factor is generally a reliable clinical guide to reducibility, the late cases should be viewed with greater caution. Long duration of symptoms, however, is not per se a contraindication to an attempt at hydrostatic reduction. PMID:13230908

  9. Testing of an automated online EA-IRMS method for fast and simultaneous carbon content and stable isotope measurement of aerosol samples

    Science.gov (United States)

    Major, István; Gyökös, Brigitta; Túri, Marianna; Futó, István; Filep, Ágnes; Hoffer, András; Molnár, Mihály

    2016-04-01

    Comprehensive atmospheric studies have demonstrated that carbonaceous aerosol is one of the main components of atmospheric particulate matter over Europe. Various methods, considering optical or thermal properties, have been developed for quantification of the accurate amount of both organic and elemental carbon constituents of atmospheric aerosol. The aim of our work was to develop an alternative fast and easy method for determination of the total carbon content of individual aerosol samples collected on prebaked quartz filters whereby the mass and surface concentration becomes simply computable. We applied the conventional "elemental analyzer (EA) coupled online with an isotope ratio mass spectrometer (IRMS)" technique which is ubiquitously used in mass spectrometry. Using this technique we are able to measure simultaneously the carbon stable isotope ratio of the samples, as well. During the developing process, we compared the EA-IRMS technique with an off-line catalytic combustion method worked out previously at Hertelendi Laboratory of Environmental Studies (HEKAL). We tested the combined online total carbon content and stable isotope ratio measurement both on standard materials and real aerosol samples. Regarding the test results the novel method assures, on the one hand, at least 95% of carbon recovery yield in a broad total carbon mass range (between 100 and 3000 ug) and, on the other hand, a good reproducibility of stable isotope measurements with an uncertainty of ± 0.2 per mill. Comparing the total carbon results obtained by the EA-IRMS and the off-line catalytic combustion method we found a very good correlation (R2=0.94) that proves the applicability of both preparation method. Advantages of the novel method are the fast and simplified sample preparation steps and the fully automated, simultaneous carbon stable isotope ratio measurement processes. Furthermore stable isotope ratio results can effectively be applied in the source apportionment

  10. Stable carbon isotope fractionation in pollen of Atlas cedar: first steps towards a new palaeoecological proxy for Northwest Africa

    Science.gov (United States)

    Bell, Benjamin; Fletcher, William; Ryan, Peter; Grant, Helen; Ilmen, Rachid

    2016-04-01

    Analysis of stable carbon isotopes can provide information on climate and the environmental conditions at different growth stages of the plant, both past and present. Carbon isotope discrimination in plant tissue is already well understood, and can be used as a drought stress indicator for semi-arid regions. Stable carbon isotope ratios measured directly on pollen provides the potential for the development of long-term environmental proxies (spanning thousands of years), as pollen is well preserved in the environment. Atlas Cedar (Cedrus atlantica Endl. Manetti ex Carrière), is an ideal test case to develop a pollen stable carbon isotope proxy. The tree grows across a wide altitudinal and climatic range and is extremely sensitive to moisture availability. The pollen is abundant, and easily identifiable to the species level in pollen analysis because different cedar species are geographically confined to different regions of the world. In 2015 we sampled 76 individual cedar trees across latitudinal, altitudinal and environmental gradients, highly focused on the Middle Atlas region of Morocco, with 25 additional samples from botanical gardens across Europe and the US to extend these gradients. Here, we report new stable carbon isotope data from pollen, leaf and stem wood from these samples with a view to assessing and quantifying species-specific fractionation effects associated with pollen production. The isotopic response of individual trees at local and wider geographical scales to altitude and climatic conditions is presented. This research forms part of an ongoing PhD project working to develop and calibrate a modern carbon isotope proxy in Atlas cedar pollen, which can ultimately be applied to fossil sequences and complement existing multi-proxy records (e.g. pollen analysis in lake sediments, tree-rings).

  11. Barium and radium radiopolarography

    International Nuclear Information System (INIS)

    Fourest, B.

    1979-01-01

    Radiopolarography has been applied to the study of two elements (barium and radium) which is difficult by classical polarography because of their strong electropositivity. Various parameters have been considered: nature, concentration and pH of supporting electrolyte. In any case of investigated mediums, the reduction to the metallic state reaction appeared to be reversible. An important variation of the barium half-wave potential E 1/2 with the ionic strength μ of the solution, imposed by LiCl used as supporting electrolyte, has been observed. It gives the possibility to estimate, for μ = 0, E 1/2 (Ba) = - 1.916 V/S.C.E. and E 1/2(Ra) = - 1.852 V/S.C.E. The values of barium and radium half wave potentials, obtained with a good accuracy in LiCl (or LiClO 4 ) 0.1 M medium, have been used to establish the amalgamation energy Δ 2 (M) of these elements. A linear variation of Δ 2 (M) with the metallic radius of the 2a elements has been obtained. On the other hand, by making the concentration of the complex forming agent (Cit 3- ) vary in the solution, we have a shift in the half wave potential from which we can deduce the stability constant of the complexe and its composition (BaCit - ; pK 1 =2). At last, nature and concentration of the supporting electrolyte (between 5.10 -2 M and 5M) have a determining influence on the extent of the polarogram plateau. This plateau is limited by an 'hollow effect' preceding the supporting electrolyte discharge. An interpretation of this effect is suggested which is based on the Stern model [fr

  12. Status of barium studies in the present era of oncology: Are they a history?

    Science.gov (United States)

    Mahajan, Abhishek; Desai, Subash; Sable, Nilesh Pandurang; Thakur, Meenakshi Haresh

    2016-01-01

    With the advent of the modern imaging technologies, the present era of oncology is seeing steady decline in requests for barium studies due to the many reasons. It is prudent to mention here, that, barium examinations cannot be made obsolete! Our aim to preserve the age old technique of barium studies not only to keep it going on but also for the betterment and appropriate management of the patient. Our goal is not to "save" barium studies simply to keep this technology alive, per se, but rather to preserve barium radiology for the quality in patient care.

  13. Role of Barium Swallow in Diagnosing Clinically Significant Anastomotic Leak following Esophagectomy

    Directory of Open Access Journals (Sweden)

    Simon Roh

    2016-04-01

    Full Text Available Background: Barium swallow is performed following esophagectomy to evaluate the anastomosis for detection of leaks and to assess the emptying of the gastric conduit. The aim of this study was to evaluate the reliability of the barium swallow study in diagnosing anastomotic leaks following esophagectomy. Methods: Patients who underwent esophagectomy from January 2000 to December 2013 at our institution were investigated. Barium swallow was routinely done between days 5–7 to detect a leak. These results were compared to clinically determined leaks (defined by neck wound infection requiring jejunal feeds and or parenteral nutrition during the postoperative period. The sensitivity and specificity of barium swallow in diagnosing clinically significant anastomotic leaks was determined. Results: A total of 395 esophagectomies were performed (mean age, 62.2 years. The indications for the esophagectomy were as follows: malignancy (n=320, high-grade dysplasia (n=14, perforation (n=27, benign stricture (n=7, achalasia (n=16, and other (n=11. A variety of techniques were used including transhiatal (n=351, McKeown (n=35, and Ivor Lewis (n=9 esophagectomies. Operative mortality was 2.8% (n=11. Three hundred and sixty-eight patients (93% underwent barium swallow study after esophagectomy. Clinically significant anastomotic leak was identified in 36 patients (9.8%. Barium swallow was able to detect only 13/36 clinically significant leaks. The sensitivity of the swallow in diagnosing a leak was 36% and specificity was 97%. The positive and negative predictive values of barium swallow study in detecting leaks were 59% and 93%, respectively. Conclusion: Barium swallow is an insensitive but specific test for detecting leaks at the cervical anastomotic site after esophagectomy.

  14. Studies on phase evolution and electrical conductivity of barium doped gadolinium aluminate

    International Nuclear Information System (INIS)

    Sinha, Amit; Sharma, B.P.; Gopalan, P.

    2012-01-01

    Highlights: ► Barium doped GdAlO 3 compositions were prepared from citrate gel derived powders. ► The solid solubility of barium in GdAlO 3 was less than 4 mol%. ► The un-dissolved barium precipitated in the form of BaAl 2 O 4 phase. ► The conductivity of Ba-doped GdAlO 3 increased with increasing amounts of Ba. ► In Gd 1−x Ba x AlO 3−δ system, specimen with x = 0.02 exhibited maximum conductivity. - Abstract: The phase evolution and electrical conductivity of barium doped GdAlO 3 samples have been investigated. The Ba- doped compositions of GdAlO 3 were prepared through citrate gel process. Analysis of the phases was carried out using X-ray diffraction (XRD). The morphology of the calcined powders was studied by scanning electron microscopy. The electrical conductivity of Gd 1−x Ba x AlO 3−δ (x = 0–0.04) was measured using ac impedance spectroscopy as a function of temperature ranging from 300 to 1000 °C under air. The solid solubility of barium in GdAlO 3 was found to be less than 4 mol%. The undissolved barium precipitated in the form of BaAl 2 O 4 phase. The barium doped GdAlO 3 powders obtained after calcination at 1000 °C was found to be porous agglomerate composed of nanocrystalline grains. The total electrical conductivity of Ba-doped GdAlO 3 increased with increasing amounts of barium up to 2 mol% doping.

  15. The diagnosis of gastro-esophageal reflux disease cannot be made with barium esophagograms

    NARCIS (Netherlands)

    Saleh, C. M. G.; Smout, A. J. P. M.; Bredenoord, A. J.

    2015-01-01

    For over 50 years, barium studies have been used to diagnose gastro-esophageal reflux disease (GERD), but the value of this test is controversial. Our study aimed to determine if barium esophagograms can be used to diagnose GERD. Barium esophagograms and pH-impedance measurement were performed in 20

  16. Petrography and stable isotope geochemistry of Oligocene-Miocene continental carbonates in south Texas: Implications for paleoclimate and paleoenvironment near sea-level

    Science.gov (United States)

    Godfrey, Conan; Fan, Majie; Jesmok, Greg; Upadhyay, Deepshikha; Tripati, Aradhna

    2018-05-01

    Cenozoic sedimentary rocks in the southern Texas Gulf Coastal Plains contain abundant continental carbonates that are useful for reconstructing terrestrial paleoclimate and paleoenvironment in a region near sea-level. Our field observations and thin section characterizations of the Oligocene and Miocene continental carbonates in south Texas identified three types of pedogenic carbonates, including rhizoliths, carbonate nodules, and platy horizons, and two types of groundwater carbonates, including carbonate-cemented beds and carbonate concretions, with distinctive macromorphologic and micromorphologic features. Based on preservations of authigenic microfabrics and variations of carbon and oxygen isotopic compositions, we suggest these carbonates experienced minimal diagenesis, and their stable isotopic compositions reflect paleoclimate and paleoenvironment in south Texas. Our Oligocene and Miocene carbonate clumped isotope temperatures (T(Δ47)) are 23-28 °C, slightly less than or comparable to the range of modern mean annual and mean warm season air temperature (21-27 °C) in the study area. These T(Δ47) values do not show any dependency on carbonate-type, or trends through time suggesting that groundwater carbonates were formed at shallow depths. These data could indicate that air temperature in south Texas was relatively stable since the early Oligocene. The reconstructed paleo-surface water δ18O values are similar to modern surface water which could indicate that meteoric water δ18O values also remained stable since the early Oligocene. Mean pedogenic carbonate δ13C values increased - 4.6‰ during the late Miocene, most likely reflecting an expansion of C4 grassland in south Texas. This study provides the first mid- and late Cenozoic continental records of paleoclimate and paleoecology in a low-latitude, near sea-level region.

  17. Stable isotopes of carbon and nitrogen as markers of dietary variation among sociocultural subgroups of Inuit in Greenland

    DEFF Research Database (Denmark)

    Bjerregaard, Peter; Larsen, Christina V L; Dahl-Petersen, Inger K

    2017-01-01

    OBJECTIVES: We assessed the use of stable isotopes of carbon and nitrogen as biomarkers for traditional versus store-bought food among the Inuit. Furthermore, we compared the isotope patterns among sociocultural population groups. METHODS: As a part of a country-wide health survey in Greenland...... food in the diet was estimated at 21% from the mean δ(13) C value, 25% from the mean δ(15) N value, and 23% from the FFQ. CONCLUSION: Nail samples for analysis of stable isotopes of carbon and nitrogen were convenient to collect during a large population health survey among the Inuit. Isotope...

  18. Chemically stable Dy–Y double substituted barium zirconate with high proton conductivity and improved sinterability

    Energy Technology Data Exchange (ETDEWEB)

    Paydar, M.H., E-mail: paaydar@shirazu.ac.ir [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Nishimura, Ch. [Hydrogen Materials Unit, Environment and Energy Materials Division, National Institute for Materials Science, Tsukuba, Ibaraki (Japan); Kobayashi, K. [Advanced Ceramics Group, Materials Processing Unit, Advanced Key Technologies Division, National Institute for Materials Science, Tsukuba, Ibaraki (Japan)

    2015-10-05

    Highlights: • BaZr{sub (0.8−x)}Dy{sub x}Y{sub 0.2}O{sub 3−δ} (0 ⩽ x ⩽ 0.2) powders were synthesized by a wet chemical route. • The ability of the synthesized powders in uptaking water was determined. • Chemical stability of the synthesized powders was evaluated under in wet and CO{sub 2} atmosphere. • The conductivity of the sintered pellets was measured by AC impedance spectroscopy. • It was shown that Dy-doped BZY20 ceramic has excellent proton conductivity. • It was proved that Dy-doped BZY20 ceramic has good chemical stability. • It was concluded that Dy-doped BZY20 electrolyte can be considered as a promising electrolyte for solid oxide fuel cell applications. - Abstract: Novel proton conductors BaZr{sub (0.8−x)}Dy{sub x}Y{sub 0.2}O{sub 3−δ} (BZ{sub 0.8−x}D{sub x}Y20, 0 ⩽ x ⩽ 0.2) with high proton conductivity, chemical stability and improved sinterability are developed by partially substituting the Zr site of the 20 mol% Y-doped barium zirconate (BZY20) with Dy. A modified Pechini method was applied to synthesize the BZ{sub 0.8−x}D{sub x}Y20 powders. The X-ray diffraction patterns of the well-calcined powders indicated that the specimens with 0 ⩽ x ⩽ 0.2 possessed a single-phase of cubic perovskite-type oxides. Stability tests under both CO{sub 2} and moist air atmospheres demonstrated that the excellent chemical stability of the base BZY20 material was not influenced by the introduction of Dy. High density pellets with larger grain sizes were obtained at temperatures lower than those commonly employed for the base Y-doped barium zirconate compound. The proton conductivities, measured in different oxidizing and reducing, dry and humidified atmospheres by impedance spectroscopy, were significantly influenced by the Dy amount. In overall, BaZr{sub (0.8−x)}Dy{sub x}Y{sub 0.2}O{sub 3−δ} solid solutions having Dy ∼ 5–10% showed excellent chemical stability and high conductivity (above 10{sup −2} S cm{sup −1} at

  19. Barium contributions to the valence electronic structure of YBa2Cu3O7-δ, PrBa2Cu3O7-δ, and other barium-containing compounds

    International Nuclear Information System (INIS)

    Mueller, D.R.; Wallace, J.S.; Jia, J.J.; O'Brien, W.L.; Dong, Q.; Callcott, T.A.; Miyano, K.E.; Ederer, D.L.

    1995-01-01

    Monochromatic photon beams were used to excite barium N IV,V soft x-ray emission spectra from YBa 2 Cu 3 O 7-δ , PrBa 2 Cu 3 O 7-δ , BaF 2 , and BaTiO 3 . Near threshold excitation was used to demonstrate that small contributions to the barium N V and N IV emission spectra in the energy region above the 5p→4d core-core transitions do not arise as satellite emission from transitions in multiply excited atoms but rather occur as a result of transitions from the valence states. The emission spectrum of YBa 2 Cu 3 O 7-δ and PrBa 2 Cu 3 O 7-δ reveals a contribution to the electronic density of states at the barium site in the region near the Fermi level. The YBa 2 Cu 3 O 7-δ compound is a superconductor and PrBa 2 Cu 3 O 7-δ is an insulator. It has been proposed that the difference between them is due to mixing of praseodymium and barium among the sites occupied by yttrium and barium, with an accompanying change in electronic structure. However, our measurements indicate that the barium partial density of states for the two compounds are essentially identical

  20. Synthesis and properties of barium diketonates as precursors for MOCVD

    Energy Technology Data Exchange (ETDEWEB)

    Drozdov, A.A. (Dept. of Chemistry, Moscow State Univ. (Russian Federation)); Troyanov, S.I. (Dept. of Chemistry, Moscow State Univ. (Russian Federation)); Kuzmina, N.P. (Dept. of Chemistry, Moscow State Univ. (Russian Federation)); Martynenko, L.I. (Dept. of Chemistry, Moscow State Univ. (Russian Federation)); Alikhanyan, A.S. (Dept. of Chemistry, Moscow State Univ. (Russian Federation)); Malkerova, I.P. (Dept. of Chemistry, Moscow State Univ. (Russian Federation))

    1993-08-01

    The structures of barium diketonates depend on the way in which they are synthesized. It is shown that there is a correlation between the volatility of these compounds and their crystal structures. A new volatile mononuclear adduct of barium dipivaloylmethanate suitable for MOCVD is suggested. (orig.).

  1. Synthesis and properties of barium diketonates as precursors for MOCVD

    International Nuclear Information System (INIS)

    Drozdov, A.A.; Troyanov, S.I.; Kuzmina, N.P.; Martynenko, L.I.; Alikhanyan, A.S.; Malkerova, I.P.

    1993-01-01

    The structures of barium diketonates depend on the way in which they are synthesized. It is shown that there is a correlation between the volatility of these compounds and their crystal structures. A new volatile mononuclear adduct of barium dipivaloylmethanate suitable for MOCVD is suggested. (orig.)

  2. Diagnostic role of barium enema in carcinoma rectum

    International Nuclear Information System (INIS)

    Asghar, M.

    2003-01-01

    Objective: The main aim of this barium enema study was to evaluate its role in patients suspected to have rectal pathologies with complaints of change in bowel habit, anorexia/weight loss, bleeding per rectum and acute/sub-acute colonic obstruction. Results: barium enema study as screening test for colo-rectal carcinoma was undertaken. Contrast outlined the colonic growth in 35 cases, out of which the cases of carcinoma colon were 24 including 13 patients suffering from carcinoma rectum. The percentage of carcinoma colon to total colonic growth was 68% while, carcinoma rectum to total carcinoma colon was 54%. Conclusion: On the basis of these investigations, it is concluded that patient's compliance is important factor in the early detection of colonic neoplasia. Though results of colonoscopy are more reliable but in practice, barium enema (double contrast) is performed initially to outline the lesion and then colonoscopy for biopsy purpose. (author)

  3. Engineered in situ bioremediation of a petroleum hydrocarbon-contaminated aquifer: assessment of mineralization based on alkalinity, inorganic carbon and stable carbon isotope balances

    Science.gov (United States)

    Hunkeler, Daniel; Höhener, Patrick; Bernasconi, Stefano; Zeyer, Josef

    1999-04-01

    A concept is proposed to assess in situ petroleum hydrocarbon mineralization by combining data on oxidant consumption, production of reduced species, CH 4, alkalinity and dissolved inorganic carbon (DIC) with measurements of stable isotope ratios. The concept was applied to a diesel fuel contaminated aquifer in Menziken, Switzerland, which was treated by engineered in situ bioremediation. In the contaminated aquifer, added oxidants (O 2 and NO 3-) were consumed, elevated concentrations of Fe(II), Mn(II), CH 4, alkalinity and DIC were detected and the DIC was generally depleted in 13C compared to the background. The DIC production was larger than expected based on the consumption of dissolved oxidants and the production of reduced species. Stable carbon isotope balances revealed that the DIC production in the aquifer originated mainly from microbial petroleum hydrocarbon mineralization, and that geochemical reactions such as carbonate dissolution produced little DIC. This suggests that petroleum hydrocarbon mineralization can be underestimated if it is determined based on concentrations of dissolved oxidants and reduced species.

  4. Preliminary Study: Application of Off-Axis ICOS to Determine Stable Carbon Isotope in Dissolved Inorganic Carbon

    Science.gov (United States)

    Kim, Y. T.; Lee, J. M.; Hwang, J. H.; Piao, J.; Woo, N. C.

    2015-12-01

    CO2 is one of the major causes for global climate change. Because stable carbon isotope ratio is used to trace carbon source, several analytical techniques likes IRMS (Isotope Ratio Mass Spectrometry) and LAS (Laser Absorption Spectrometry) were extensively used. Off-axis ICOS, a kind of LAS, has merits on long-term stability and field application, therefore it is widely being used in CCS (Carbon Capture and Storage) field. The aim of this study is to extend the application scope of OA-ICOS to determine dissolved inorganic carbon (DIC). Because OA-ICOS showed dependence of δ13C on CO2 concentration, data processing is required. We tested CO2 Carbon Isotope Analyzer (CCIA-36-EP, Los Gatos Research) with both reference gas (δ13C= -28.28‰) and aqueous solutions prepared by dissolving sodium bicarbonate standards (δ13C= -12.26‰ and +3.96‰). The differences of δ13C between reference and measurement values are plotted by CO2 concentrations, then compared. At first, we checked the similarity between our curve pattern for reference gas and Guillon's research (δ13C= -43.99‰) by other Analyzer. To analyze aqueous samples, more errors can be caused than gas analysis. The carbon isotope fractionation occurs during dissolving standard reagents and extracting DIC as CO2 gas form. This effect is mixed with CO2 concentration dependence effect, therefore the curve patterns are different with that for reference gas. Our experiments are done for various δ13C values. It could be an important point to use OA-ICOS to analyze DIC, too.

  5. Aspiration of barium contrast medium in an elderly man with disordered swallowing

    OpenAIRE

    Bağcı Ceyhan, B.; Çelikel, T.; Koç, M.; Ahıskalı, R.; Biren, T.; Ataizi Çelikel, Ç.

    1995-01-01

    The aspiration of contrast medium during the investigation of gastrointestinal diseases is a well recognized hazard, particularly in patients with swallowing disorders. A case is reported in which accidental aspiration of contrast barium occurred owing to disordered swallowing in an elderly man. The infiltration on chest x-ray persisted 2 years after barium contrast aspiration. Inflammatory reaction and retractile, granular material observed in lung biopsy specimens suggested barium-induced p...

  6. Synthesis and surface properties of submicron barium sulfate particles

    International Nuclear Information System (INIS)

    Zhang Ming; Zhang Bao; Li Xinhai; Yin Zhoulan; Guo Xueyi

    2011-01-01

    Barium sulfate particles were synthesized in the presence of EDTA at room temperature. X-ray diffractometry (XRD), Fourier transform infrared resonance (FTIR) and scanning electron microscopy (SEM) were used to characterize the structure and morphology of BaSO 4 particles. The effect of the preparation parameters on the particle size distribution and morphology was investigated. The conditional formation constants of Ba-EDTA at different pH values were calculated. The results show that the size and morphology of BaSO 4 particles can be effectively controlled by adding EDTA in the precipitation process. Among all the operation conditions, the pH value has significant effect on the particle size. The obtained barium sulfate particles are spherical and well dispersed at pH = 9-10. Zeta potentials of BaSO 4 were measured at different pH. The isoelectric point (IEP) of barium sulfate colloid appears at pH 6.92. The model of the solid-solution interface at a particle of BaSO 4 was presented. The FTIR result indicates that the surface of the prepared BaSO 4 absorbs the functional groups of EDTA, which lower the IEP of the barium sulfate particles.

  7. Synthesis and surface properties of submicron barium sulfate particles

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ming, E-mail: csu.light@yahoo.com.cn [College of Chemistry and Chemical Engineering, Zhaoqing University, Zhaoqing 526061 (China); School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Zhang Bao; Li Xinhai [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China); Yin Zhoulan [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Guo Xueyi [School of Metallurgical Science and Engineering, Central South University, Changsha 410083 (China)

    2011-10-15

    Barium sulfate particles were synthesized in the presence of EDTA at room temperature. X-ray diffractometry (XRD), Fourier transform infrared resonance (FTIR) and scanning electron microscopy (SEM) were used to characterize the structure and morphology of BaSO{sub 4} particles. The effect of the preparation parameters on the particle size distribution and morphology was investigated. The conditional formation constants of Ba-EDTA at different pH values were calculated. The results show that the size and morphology of BaSO{sub 4} particles can be effectively controlled by adding EDTA in the precipitation process. Among all the operation conditions, the pH value has significant effect on the particle size. The obtained barium sulfate particles are spherical and well dispersed at pH = 9-10. Zeta potentials of BaSO{sub 4} were measured at different pH. The isoelectric point (IEP) of barium sulfate colloid appears at pH 6.92. The model of the solid-solution interface at a particle of BaSO{sub 4} was presented. The FTIR result indicates that the surface of the prepared BaSO{sub 4} absorbs the functional groups of EDTA, which lower the IEP of the barium sulfate particles.

  8. Prospective comparison of double contrast barium enema plus flexible sigmoidoscopy v colonoscopy in rectal bleeding: barium enema v colonoscopy in rectal bleeding.

    OpenAIRE

    Irvine, E J; O'Connor, J; Frost, R A; Shorvon, P; Somers, S; Stevenson, G W; Hunt, R H

    1988-01-01

    Rectal bleeding often heralds serious colonic disease. The literature suggests that colonoscopy is superior to barium enema plus sigmoidoscopy, although no good comparative studies exist. Seventy one patients with overt rectal bleeding had prospectively flexible sigmoidoscopy, double contrast barium enema and colonoscopy completed independently. Against the gold standard, the sensitivity and specificity of colonoscopy were 0.69 and 0.78 respectively for a spectrum of colonic lesions, while fo...

  9. Effect of Different Carbon Substrates on Nitrate Stable Isotope Fractionation During Microbial Denitrification

    DEFF Research Database (Denmark)

    Wunderlich, Anja; Meckenstock, Rainer; Einsiedl, Florian

    2012-01-01

    -labeled water and 18O-labeled nitrite were added to the microcosm experiments to study the effect of putative backward reactions of nitrite to nitrate on the stable isotope fractionation. We found no evidence for a reverse reaction. Significant variations of the stable isotope enrichment factor ε were observed......In batch experiments, we studied the isotope fractionation in N and O of dissolved nitrate during dentrification. Denitrifying strains Thauera aromatica and “Aromatoleum aromaticum strain EbN1” were grown under strictly anaerobic conditions with acetate, benzoate, and toluene as carbon sources. 18O...... of nitrate transport across the cell wall compared to the kinetics of the intracellular nitrate reduction step of microbial denitrification....

  10. Printed Barium Strontium Titanate capacitors on silicon

    Energy Technology Data Exchange (ETDEWEB)

    Sette, Daniele [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Luxembourg Institute of Science and Technology LIST, Materials Research and Technology Department, L-4422 Belvaux (Luxembourg); Kovacova, Veronika [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Defay, Emmanuel, E-mail: emmanuel.defay@list.lu [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Luxembourg Institute of Science and Technology LIST, Materials Research and Technology Department, L-4422 Belvaux (Luxembourg)

    2015-08-31

    In this paper, we show that Barium Strontium Titanate (BST) films can be prepared by inkjet printing of sol–gel precursors on platinized silicon substrate. Moreover, a functional variable capacitor working in the GHz range has been made without any lithography or etching steps. Finally, this technology requires 40 times less precursors than the standard sol–gel spin-coating technique. - Highlights: • Inkjet printing of Barium Strontium Titanate films • Deposition on silicon substrate • Inkjet printed silver top electrode • First ever BST films thinner than 1 μm RF functional variable capacitor that has required no lithography.

  11. Rapid and accurate determination of barium by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Armelin, Maria Jose A.; Maihara, Vera A.; Saiki, Mitiko; Trevizam, Anderson R.

    2013-01-01

    Barium is an alkaline earth metal naturally present in soils. When available at a high level in the soil it can cause toxicity to plants and animals. Not all the barium is readily available to living organisms. Inorganic and organic barium compounds can be presented as soluble or insoluble forms in the soil. The soluble form of BaS is extremely toxic to humans, animals and plants. Researchers have noted a decrease of K absorption in the plant when Ba concentrations are increased and a change in overall plant growth. In case of animals, Ba tends to be concentrated in the bones which may compete with calcium, although only about 2% barium ingested in dietary is absorbed by the body. Another effect is that the Ba can interfere with the availability of sulfur in the soil due to the sulphate formation of low solubility. Barium and some other elements are considered palioclimatic proxies. For some researchers, barite is perhaps the most appropriate indicator of paleoproductivity because of a high resistance to dissolution. As explained about the barium effects in various situations, it was considered important to study the more appropriated experimental conditions for determination of this element by INAA. Conditions established for this analysis were: a) Irradiation time, 15 and 40 seconds, under thermal flux neutron about 4 x 10 12 n cm -2 s -1 , for determining barium in geological and biological matrices, respectively; b) Decay time, approximately of 4 minutes; c) Counting time of 30 minutes; d) Radionuclide measured 139 Ba. The quality of Ba results was evaluated from the analysis of certified reference materials. The performance of the method was satisfactory, according to the criterion of E.ζ score. Results obtained in this study indicate INAA is a good alternative for Ba determination in geological and biological samples. (author)

  12. Highly stable porous silicon-carbon composites as label-free optical biosensors.

    Science.gov (United States)

    Tsang, Chun Kwan; Kelly, Timothy L; Sailor, Michael J; Li, Yang Yang

    2012-12-21

    A stable, label-free optical biosensor based on a porous silicon-carbon (pSi-C) composite is demonstrated. The material is prepared by electrochemical anodization of crystalline Si in an HF-containing electrolyte to generate a porous Si template, followed by infiltration of poly(furfuryl) alcohol (PFA) and subsequent carbonization to generate the pSi-C composite as an optically smooth thin film. The pSi-C sensor is significantly more stable toward aqueous buffer solutions (pH 7.4 or 12) compared to thermally oxidized (in air, 800 °C), hydrosilylated (with undecylenic acid), or hydrocarbonized (with acetylene, 700 °C) porous Si samples prepared and tested under similar conditions. Aqueous stability of the pSi-C sensor is comparable to related optical biosensors based on porous TiO(2) or porous Al(2)O(3). Label-free optical interferometric biosensing with the pSi-C composite is demonstrated by detection of rabbit IgG on a protein-A-modified chip and confirmed with control experiments using chicken IgG (which shows no affinity for protein A). The pSi-C sensor binds significantly more of the protein A capture probe than porous TiO(2) or porous Al(2)O(3), and the sensitivity of the protein-A-modified pSi-C sensor to rabbit IgG is found to be ~2× greater than label-free optical biosensors constructed from these other two materials.

  13. Simultaneous determination of stable carbon, oxygen, and hydrogen isotopes in cellulose.

    Science.gov (United States)

    Loader, N J; Street-Perrott, F A; Daley, T J; Hughes, P D M; Kimak, A; Levanič, T; Mallon, G; Mauquoy, D; Robertson, I; Roland, T P; van Bellen, S; Ziehmer, M M; Leuenberger, M

    2015-01-06

    A technological development is described through which the stable carbon-, oxygen-, and nonexchangeable hydrogen-isotopic ratios (δ(13)C, δ(18)O, δ(2)H) are determined on a single carbohydrate (cellulose) sample with precision equivalent to conventional techniques (δ(13)C 0.15‰, δ(18)O 0.30‰, δ(2)H 3.0‰). This triple-isotope approach offers significant new research opportunities, most notably in physiology and medicine, isotope biogeochemistry, forensic science, and palaeoclimatology, when isotopic analysis of a common sample is desirable or when sample material is limited.

  14. TV observations of the Barium-GEOS ion jet experiment

    International Nuclear Information System (INIS)

    Hapgood, M.A.; Collin, H.L.; Rothwell, P.

    1980-01-01

    The barium jet released by the Barium-GEOS rocket was observed by low light television cameras at Skibotn, Norway and Esrange, Sweden. The release produced a single well-defined jet containing barium ions with initial velocities between 7 and 12 km s -1 systematically slower than the velocities reported in previous experiments. Accurate data on the motion of the jet has been obtained for the first two minutes after release (up to a height of 2000 km). The orientation of the jet was close to that of an IGRF1975 model field line but was significantly different from that predicted by the Barraclough and Olson field model. The motion of the jet across the field lines was southwards with a velocity of about 150 m s -1 . (Auth.)

  15. Barium titanate thick films prepared by screen printing technique

    Directory of Open Access Journals (Sweden)

    Mirjana M. Vijatović

    2010-06-01

    Full Text Available The barium titanate (BaTiO3 thick films were prepared by screen printing technique using powders obtained by soft chemical route, modified Pechini process. Three different barium titanate powders were prepared: i pure, ii doped with lanthanum and iii doped with antimony. Pastes for screen printing were prepared using previously obtained powders. The thick films were deposited onto Al2O3 substrates and fired at 850°C together with electrode material (silver/palladium in the moving belt furnace in the air atmosphere. Measurements of thickness and roughness of barium titanate thick films were performed. The electrical properties of thick films such as dielectric constant, dielectric losses, Curie temperature, hysteresis loop were reported. The influence of different factors on electrical properties values was analyzed.

  16. A 66 fs highly stable single wall carbon nanotube mode locked fiber laser

    International Nuclear Information System (INIS)

    Yu, Zhenhua; Zhang, Xiao; Dong, Xinzheng; Tian, Jinrong; Song, Yanrong; Wang, Yonggang

    2014-01-01

    We demonstrate a highly stable mode locked fiber laser based on single wall carbon nanotubes. The mode locking is achieved by the evanescent field interaction of the propagating light with a single wall carbon nanotube saturable absorber in a microfiber. The pulse width is 66 fs, which, to the best of our knowledge, is the shortest pulse achieved in a carbon nanotube mode locked fiber laser. The maximum average output power is 26 mW, which is about 20 times larger than that of a typical carbon nanotube mode locked fiber laser. The center of the wavelength is 1555 nm, with 54 nm spectral width. The repetition rate is 146 MHz. To investigate the laser’s stability, the output pulses are monitored for 120 h and there is no significant degradation of the laser spectral width or shape. (paper)

  17. Effects of powdered versus liquid barium on the viscosity of fluids used in modified swallow studies

    International Nuclear Information System (INIS)

    Baron, J.; Alexander, T.

    2003-01-01

    To determine if the viscosity of thickened juice mixtures used in modified barium swallow studies significantly changes with the addition of powdered barium. We also describe a test formulation created using liquid barium, which has a negligible effect on juice viscosity. The viscosities of water and standardized honey- and nectar-consistency juices mixed with different amounts of powdered barium were measured by timing the laminar flow of a given initial hydrostatic head of fluid under gravity though an orifice of fixed diameter. Standardized juices were then mixed with a liquid formulation of barium and with measured quantities of water to produce viscosities that more closely equated with those of the standardized juices. With the addition of powdered barium, viscosity increased in all fluids, most markedly with the nectar-consistency juice. Liquid barium formulations maintained the viscosities of the original thickened juices. Rendering juices radio-opaque with barium powder results in dramatic increases in the viscosity of the resulting mixture and compromises diagnostic accuracy. Liquid barium preparations have the advantage that they can be rapidly and accurately dispensed by syringe, and their use does not significantly increase the viscosity of the preparation. (author)

  18. Effects of powdered versus liquid barium on the viscosity of fluids used in modified swallow studies

    Energy Technology Data Exchange (ETDEWEB)

    Baron, J.; Alexander, T. [Univ. of Alberta, Dept. of Radiology, Edmonton, Alberta (Canada)

    2003-06-01

    To determine if the viscosity of thickened juice mixtures used in modified barium swallow studies significantly changes with the addition of powdered barium. We also describe a test formulation created using liquid barium, which has a negligible effect on juice viscosity. The viscosities of water and standardized honey- and nectar-consistency juices mixed with different amounts of powdered barium were measured by timing the laminar flow of a given initial hydrostatic head of fluid under gravity though an orifice of fixed diameter. Standardized juices were then mixed with a liquid formulation of barium and with measured quantities of water to produce viscosities that more closely equated with those of the standardized juices. With the addition of powdered barium, viscosity increased in all fluids, most markedly with the nectar-consistency juice. Liquid barium formulations maintained the viscosities of the original thickened juices. Rendering juices radio-opaque with barium powder results in dramatic increases in the viscosity of the resulting mixture and compromises diagnostic accuracy. Liquid barium preparations have the advantage that they can be rapidly and accurately dispensed by syringe, and their use does not significantly increase the viscosity of the preparation. (author)

  19. Stable isotope analysis in primatology: a critical review.

    Science.gov (United States)

    Sandberg, Paul A; Loudon, James E; Sponheimer, Matt

    2012-11-01

    Stable isotope analysis has become an important tool in ecology over the last 25 years. A wealth of ecological information is stored in animal tissues in the relative abundances of the stable isotopes of several elements, particularly carbon and nitrogen, because these isotopes navigate through ecological processes in predictable ways. Stable carbon and nitrogen isotopes have been measured in most primate taxonomic groups and have yielded information about dietary content, dietary variability, and habitat use. Stable isotopes have recently proven useful for addressing more fine-grained questions about niche dynamics and anthropogenic effects on feeding ecology. Here, we discuss stable carbon and nitrogen isotope systematics and critically review the published stable carbon and nitrogen isotope data for modern primates with a focus on the problems and prospects for future stable isotope applications in primatology. © 2012 Wiley Periodicals, Inc.

  20. Complications from radiographer-performed double contrast barium enemas

    Energy Technology Data Exchange (ETDEWEB)

    Vora, P.; Chapman, A. E-mail: anthony.chapman@leedsth.nhs.uk

    2004-04-01

    AIM: To determine the types and rates of complications encountered by radiographers when performing double contrast barium enemas (DCBE). MATERIALS AND METHODS: Seven hundred and forty-one questionnaires were posted to radiographers who had in the last 5 years attended one of the biannual barium enema training courses. RESULTS: Of 741 questionnaires posted 407 (54.9%) were returned completed. Approximately 348,000 barium enema examinations had been performed. Fifty-nine radiographers reported 89 complications, including 13 intra-peritoneal and 11 extra-peritoneal perforations. There were five deaths (mortality 1 in 70,000). Deaths resulted from two of 24 (10%) perforations, two of 45 (5%) cardiac events and one cerebrovascular accident that occurred during an examination. CONCLUSIONS: Radiographers have been regularly performing DCBEs for almost a decade. The mortality for radiographer-performed DCBE is similar to that previously reported for radiologists, although a slightly higher rate of perforation is noted and so this is an area where radiographer training should be targeted.

  1. Complications from radiographer-performed double contrast barium enemas

    International Nuclear Information System (INIS)

    Vora, P.; Chapman, A.

    2004-01-01

    AIM: To determine the types and rates of complications encountered by radiographers when performing double contrast barium enemas (DCBE). MATERIALS AND METHODS: Seven hundred and forty-one questionnaires were posted to radiographers who had in the last 5 years attended one of the biannual barium enema training courses. RESULTS: Of 741 questionnaires posted 407 (54.9%) were returned completed. Approximately 348,000 barium enema examinations had been performed. Fifty-nine radiographers reported 89 complications, including 13 intra-peritoneal and 11 extra-peritoneal perforations. There were five deaths (mortality 1 in 70,000). Deaths resulted from two of 24 (10%) perforations, two of 45 (5%) cardiac events and one cerebrovascular accident that occurred during an examination. CONCLUSIONS: Radiographers have been regularly performing DCBEs for almost a decade. The mortality for radiographer-performed DCBE is similar to that previously reported for radiologists, although a slightly higher rate of perforation is noted and so this is an area where radiographer training should be targeted

  2. Barium fluoride surface preparation, analysis and UV reflective coatings at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Wuest, C.R.

    1992-01-01

    Lawrence Livermore National Laboratory (LLNL) has begun a program of study on barium fluoride scintillating crystals for the Barium Fluoride Electromagnetic Calorimeter Collaboration. This program has resulted in a number of significant improvements in the mechanical processing, polishing and coating of barium fluoride crystals. Techniques have been developed using diamond-loaded pitch lapping that can produce 15 angstrom RMS surface finishes over large areas. These lapped surfaces have been shown to be crystalline using Rutherford Back-scattering (RBS). Also, special polishing fixtures have been designed based on mounting technology developed for the 1.1 m diameter optics used in LLNL's Nova Laser. These fixtures allow as many as five 25--50 cm long barium fluoride crystals to be polished and lapped at a time with the necessary tolerances for the 16,000 crystal Barium Fluoride Calorimeter. In addition, results will be presented on coating barium fluoride with UV reflective layers of magnesium fluoride and aluminum

  3. Stable cyclic performance of nickel oxide–carbon composite anode for lithium-ion batteries

    International Nuclear Information System (INIS)

    Susantyoko, Rahmat Agung; Wang, Xinghui; Fan, Yu; Xiao, Qizhen; Fitzgerald, Eugene; Pey, Kin Leong; Zhang, Qing

    2014-01-01

    Nickel oxide (NiO) directly grown on nickel foam is regarded as a promising lithium ion battery anode material which shows good cyclic and rate performances with a theoretical specific capacity of 718 mA h g −1 . In this study, we demonstrated a carbon-incorporated NiO anode (NiO–C) with a capacity per unit area of 2.11 mA h cm −2 and 1.76 mA h cm −2 at 0.2 C and 0.5 C rates, respectively, fabricated by thermal oxidation of carbon coated nickel foam. The specific capacity of our NiO–C composite samples at 0.5 C rate is found to be typically 389.16 mA h g −1 , with a stable cyclic performance up to more than 100 cycles. This remarkable performance is apparently superior to the control samples of pure NiO samples. The improved performance is contributed to carbon incorporation which serves as a fluent channel for electrons and a flexible network preventing NiO nanostructures from structural deformation during charge and discharge processes. The advantage of using our approach is the easy preparation of the NiO–C composite using a simple two-step process: chemical vapor deposition of ethanol and annealing in air. - Highlights: • We demonstrated a directly grown NiO–C anode on nickel foam substrate. • NiO–C anode was made using simple processes: CVD of ethanol and annealing in air. • The NiO–C anode has a stable cycle life up to 102 cycles. • It has an acceptable areal capacity (1.76 mA h cm −2 at 0.5 C rate) for practical use. • Carbon provides electrons path and buffering matrix preventing NiO pulverization

  4. Results of a cooperative study for the evaluation of the barium meal Falibaryt HD

    International Nuclear Information System (INIS)

    Reisinger, W.; Liess, G.; Beckmann, D.; Block, H.G.; Dietze, R.; Grosche, N.; Hall, E.; Lasch, G.; Knoth, H.J.; Kroeger, W.

    1986-01-01

    The diagnostic capabilities of radiologic investigations of the stomach in double contrast can be significantly improved with high-density low-viscosity barium meals. In the GDR the barium meal Falibaryt HD with a barium sulfate content of 215 g per 100 ml suspension has been developed. In nearly 1,000 radiologic investigations of the stomach (81% in relaxation with spasmolytics, 66% without hypotony) all fine structures were well imaged and the preparation therefore is comparable with the best barium meals presently on the market. (author)

  5. Organic carbon and nitrogen stable isotopes in the intertidal sediments from the Yangtze Estuary, China

    International Nuclear Information System (INIS)

    Liu, M. . E-mail mliu@geo.ecnu.edu.cn; Hou, L.J.; Xu, S.Y.; Ou, D.N.; Yang, Y.; Yu, J.; Wang, Q.

    2006-01-01

    The natural isotopic compositions and C/N elemental ratios of sedimentary organic matter were determined in the intertidal flat of the Yangtze Estuary. The results showed that the ratios of carbon and nitrogen stable isotopes were respectively -29.8 per mille to - 26.0 per mille and 1.6 per mille -5.5 per mille in the flood season (July), while they were -27.3 per mille to - 25.6 per mille and 1.7 per mille -7.8 per mille in the dry season (February), respectively. The δ 13 C signatures were remarkably higher in July than in February, and gradually increased from the freshwater areas to the brackish areas. In contrast, there were relatively complex seasonal and spatial changes in stable nitrogen isotopes. It was also reflected that δ 15 N and C/N compositions had been obviously modified by organic matter diagenesis and biological processing, and could not be used to trace the sources of organic matter at the study area. In addition, it was considered that the mixing inputs of terrigenous and marine materials generally dominated sedimentary organic matter in the intertidal flat. The contribution of terrigenous inputs to sedimentary organic matter was roughly estimated according to the mixing balance model of stable carbon isotopes

  6. Colonoscopy can miss diverticula of the left colon identified by barium enema.

    Science.gov (United States)

    Niikura, Ryota; Nagata, Naoyoshi; Shimbo, Takuro; Akiyama, Junichi; Uemura, Naomi

    2013-04-21

    To identify the diagnostic value of colonoscopy for diverticulosis as determined by barium enema. A total of 65 patients with hematochezia who underwent colonoscopy and barium enema were analyzed, and the diagnostic value of colonoscopy for diverticula was assessed. The receiver operating characteristic area under the curve was compared in relation to age (barium enema. Colonoscopy had a sensitivity of 91% and specificity of 90%. No significant differences were found in the receiver operating characteristic area under the curve (ROC-AUC) for age group or sex. The ROC-AUC of the left colon was significantly lower than that of the right colon (0.81 vs 0.96, P = 0.02). Colonoscopy identified 486 colonic diverticula, while barium enema identified 1186. The detection ratio for the entire colon was therefore 0.41 (486/1186). The detection ratio in the left colon (0.32, 189/588) was significantly lower than that of the right colon (0.50, 297/598) (P barium enema, only half the number of colonic diverticula can be detected by colonoscopy in the entire colon and even less in the left colon.

  7. Seasonal changes in stable carbon isotope ratios within annual growth rings of Pinus radiata

    International Nuclear Information System (INIS)

    Walcroft, A.; Silvester, W.; Whitehead, D.; Kelliher, F.

    1997-01-01

    The stable isotope composition of photosynthetically assimilated carbon (δ 13 C) is determined by the ratio of the leaf internal CO 2 concentration (c i ) to that of the ambient air (c a ), and so reflects the contribution of both stomatal conductance (g s ) and the rate of photosynthesis (A). Assimilated carbon which is subsequently laid down as wood in annual growth rings may therefore represent a time integrated record of physiological responses by the whole tree to seasonal changes in the environmental variables regulating growth. We analysed the stable carbon isotope composition of Pinus radiata wood collected from two plantation forest sites in New Zealand which differ markedly in temperature, rainfall and soil characteristics. For both sites, discs were cut from the stem of several trees near ground level and whole wood samples were taken from within individual annual growth rings over a number of years. At one site, diameter bands were installed over the 1994 - 1996 growing seasons in order to date precisely the formation of wood during that time. Trees at each site consistently showed a seasonal pattern in the stable isotope composition of wood within individual growth rings. The amplitude of seasonal δ 13 C variation at the wet and dry sites were 1-2 per thousand and 4 per thousand respectively. Mean δ 13 C values from the wet site were 3 per thousand more 13 C depleted than those from the dry site implying lower water-use efficiency (carbon assimilation per unit transpiration). A process-based, model of stomatal conductance and CO 2 assimilation was combined with a soil-water balance model to estimate the average daily leaf-level intercellular CO 2 concentration (c i ). Over two growing seasons at each site there was generally good agreement between mean canopy-level c i derived from the tree-ring δ 13 C data and modelled leaf-level c i levels. Further, the ratio of annual CO 2 assimilation to transpiration estimated by the model for each site

  8. Experimental studies on 3D printing of barium titanate ceramics for medical applications

    Directory of Open Access Journals (Sweden)

    Schult Mark

    2016-09-01

    Full Text Available The present work deals with the 3D printing of porous barium titanate ceramics. Barium titanate is a biocompatible material with piezoelectric properties. Due to insufficient flowability of the starting material for 3D printing, the barium titanate raw material has been modified in three different ways. Firstly, barium titanate powder has been calcined. Secondly, flow additives have been added to the powder. And thirdly, flow additives have been added to the calcined powder. Finally, a polymer has been added to the three materials and specimens have been printed from these three material mixtures. The 3D printed parts were then sintered at 1320°C. The sintering leads to shrinkage which differs between 29.51–71.53% for the tested material mixtures. The porosity of the parts is beneficial for cell growth which is relevant for future medical applications. The results reported in this study demonstrate the possibility to fabricate porous piezoelectric barium titanate parts with a 3D printer that can be used for medical applications. 3D printed porous barium titanate ceramics can especially be used as scaffold for bone tissue engineering, where the bone formation can be promoted by electrical stimulation.

  9. Barium ionization mechanisms in the CRRES G-1 and G-11b releases

    International Nuclear Information System (INIS)

    Hunton, D.E.

    1993-01-01

    The G-11b chemical release experiment form the Combined Release and Radiation Effects Satellite (CRRES) was conducted in darkness below the solar UV terminator to test the Critical Ionization Velocity (CIV) hypothesis. The Quadrupole Ion Mass Spectrometer (QIMS) aboard CRRES measured fluxes of barium ions from this darkness release that were only a factor of ten smaller than the G-1 release measurements in full sunlight. Possible mechanisms for this significant barium ionization in darkness include CIV, charge exchange with O + , collisional ionization and associative ionization. The authors have evaluated the relative contributions of the collisional mechanisms by constructing a simple model of barium ions from the darkness release seem to be consistent with recent measurements of the charge transfer cross section. A collective plasma ionization mechanism such as CIV does not seem to necessary in order to explain the large barium ion fluxes observed. However, QIMS could only detect barium ions formed several seconds after the initial detonation of the release canister. A CIV process could still have occurred very early in the expansion of the barium neutral cloud and the mass spectrometer would not have detected these ions

  10. Barium titanate coated with magnesium titanate via fused salt method and its dielectric property

    International Nuclear Information System (INIS)

    Chen Renzheng; Cui Aili; Wang Xiaohui; Li Longtu

    2003-01-01

    Barium titanate fine particles were coated homogeneously with magnesium titanate via the fused salt method. The thickness of the magnesium titanate film is 20 nm, as verified by TEM and XRD. The mechanism of the coating is that: when magnesium chloride is liquated in 800 deg. C, magnesium will replace barium in barium titanate, and form magnesium titanate film on the surface of barium titanate particles. Ceramics sintered from the coated particles show improved high frequency ability. The dielectric constant is about 130 at the frequency from 1 to 800 MHz

  11. Barium in produced water: Is it a toxicological hazard to the marine environment?

    International Nuclear Information System (INIS)

    Neff, J.M.

    1993-01-01

    Produced water is a complex aqueous mixture of organic and inorganic chemicals that often is generated in large volumes as a by-product of production of oil and gas. Produced water from offshore oil production platforms sometimes is treated to remove particulate oil and then discharged to the ocean. Barium often is the most abundant inorganic chemical, other than the dominant sea salts, in produced water. Some concern has been expressed that the large amounts of barium discharged to the ocean in produced water may have adverse effects on marine biological communities. The ecological risks associated with discharge to the ocean in produced water may have adverse effects on marine biological communities. The ecological risks associated with discharge to the ocean of barium in produced water were evaluated. Concentrations of barium in produced water from different sources range from less than 1.0 to about 2,000 mg/L, and are inversely correlated with concentrations of sulfate. Concentrations of barium in the ocean usually are in the range of 10 to 20 μg/L; the ocean is undersaturated with respect to barite (BaSO 4 ). During mixing and dilution of a produced water plume in the ocean, barium reacts with the abundant sulfate in seawater and precipitates as barite. Barite is completely nontoxic to marine organisms. Because of the high concentration of sulfate in the ocean, ionic barium can not reach concentrations high enough to be toxic to marine organisms

  12. Highly stable carbon coated Mg2Si intermetallic nanoparticles for lithium-ion battery anode

    Science.gov (United States)

    Tamirat, Andebet Gedamu; Hou, Mengyan; Liu, Yao; Bin, Duan; Sun, Yunhe; Fan, Long; Wang, Yonggang; Xia, Yongyao

    2018-04-01

    Silicon is an ideal candidate anode material for Li-ion batteries (LIBs). However, it suffers from rapid capacity fading due to large volume expansion upon lithium insertion. Herein, we design and fabricate highly stable carbon coated porous Mg2Si intermetallic anode material using facile mechano-thermal technique followed by carbon coating using thermal vapour deposition (TVD), toluene as carbon source. The electrode exhibits an excellent first reversible capacity of 726 mAh g-1 at a rate of 100 mA g-1. More importantly, the electrode demonstrates high rate capability (380 mAh g-1 at high rate of 2 A g-1) as well as high cycle stability, with capacity retentions of 65% over 500 cycles. These improvements are attributable to both Mg supporting medium and the uniform carbon coating, which can effectively increase the conductivity and electronic contact of the active material and protects large volume alterations during the electrochemical cycling process.

  13. Qualitative analysis of barium particles coated in small intestinal mucosa of rabbit by using scanning electron microscopy

    International Nuclear Information System (INIS)

    Lee, Yong Suk; Ha, Hyun Kwon; Lee, Yang Seob; Kim, Jae Kyun; Yoon, Seong Eon; Kim, Jung Hoon; Chung, Dong Jin; Auh, Yong Ho

    1998-01-01

    To qualitatively analysed barium coating status in the intestinal mucosa, we used scanning electron microscopy to observe barium particles coated in the small intestinal mucosa of rabbit, and we attempted to assess the relationship between electron microscopic findings and radiographic densities. Six different combination of barium and methylcellulose suspensions were infused into the resected small intestines of 15 rabbits. Barium powders were mixed with water to make 40% and 70% w/v barium solutions, and also mixed with 0.5% methylcellulose solutions were used as a double contrast agent. After the infusion of barium suspensions, a mammography unit was used to obtain radiographs of the small intestine, and their optical densities were measured by a densitometer. Thereafter, photographs of barium-coated small intestinal mucosa were obtained using a scanning electron microscope (x 8,000), and the number of barium particles in the unit area were measured. To compare the relationship between the electron microscopic findings and optical densities, statistical analysis using Spearman correlation was performed. This study shows that by using scanning electron microscopy, barium particles coated on the small intestinal mucosa can be qualitatively analysed. It also shows that the number of small barium particles measured by scanning electron microscopy is related to optical densities. (author). 14 refs., 2 figs

  14. Influence of fuel ratios on auto combustion synthesis of barium ferrite ...

    Indian Academy of Sciences (India)

    Unknown

    Influence of fuel ratios on auto combustion synthesis of barium ferrite nano particles. D BAHADUR*, S RAJAKUMAR and ANKIT KUMAR. Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology,. Mumbai 400 076 e-mail: dhirenb@iitb.ac.in. Abstract. Single-domain barium ferrite nano ...

  15. Strontium-90 sorption from fresh waters in the process of barium manganite modification

    International Nuclear Information System (INIS)

    Ryzhen'kov, A.P.; Egorov, Yu.V.

    1995-01-01

    Strontium-90 extraction by barium manganite from fresh water (natural non-salty water in open ponds) may be increased adding to the solution the sulfate anion containing reagents that modify a sorbent and chemically bind a sorbate. Heterogeneous anion-exchanging reaction of barium manganite transformation into barium sulfate-manganese dioxide and simultaneous coprecipitation of strontium sulfate (microelement) occur as a result of it. 9 refs., 4 figs., 1 tab

  16. Small bowel volvulus in children. Its appearance on the barium enema examination

    Energy Technology Data Exchange (ETDEWEB)

    Siegel, M.J.; Shackelford, G.D.; McAlister, W.H.

    1980-01-01

    Two children with small bowel volvulus diagnosed on barium enema examination are reported. In one patient the volvulus was associated with malrotation and in the other patient there was a post-operative peritoneal adhesion. In both cases the diagnosis was based on beaking of the head of the barium column at the site of volvulus. Radiographic demonstration of a beak sign in the small bowel on barium enema examination should suggest a diagnosis of small bowel volvulus, and indicates the need for immediate surgery.

  17. How does esophagus look on barium esophagram in pediatric eosinophilic esophagitis?

    Science.gov (United States)

    Al-Hussaini, Abdulrahman; AboZeid, Amany; Hai, Abdul

    2016-08-01

    The clinical, endoscopic, and histologic findings of eosinophilic esophagitis (EoE) are well characterized; however, there have been very limited data regarding the radiologic findings of pediatric EoE. We report on the radiologic findings of pediatric EoE observed on barium esophagram and correlate them with the endoscopic findings. We identified children diagnosed with EoE in our center from 2004 to 2015. Two pediatric radiologists met after their independent evaluations of each fluoroscopic study to reach a consensus on each case. Clinical and endoscopic data were collected by retrospective chart review. Twenty-six pediatric EoE cases (age range 2-13 years; median 7.5 years) had barium esophagram done as part of the diagnostic approach for dysphagia. Thirteen children had abnormal radiologic findings of esophagus (50%): rings formation (n = 4), diffuse irregularity of mucosa (n = 8), fixed stricture formation (n = 3), and narrow-caliber esophagus (n = 10). Barium esophagram failed to show one of 10 cases of narrow-caliber esophagus and 10 of 14 cases of rings formation visualized endoscopically. The mean duration of symptoms prior to diagnosis of EoE was longer (3.7 vs. 1.7 year; p value 0.019), and the presentation with intermittent food impaction was commoner in the group with abnormal barium esophagram as compared to the group with normal barium esophagram (69% vs. 8%; p value 0.04). Barium swallow study is frequently normal in pediatric EoE. With the exception of narrow-caliber esophagus, our data show poor correlation between radiologic and endoscopic findings.

  18. Tunable ferromagnetic resonance in La-Co substituted barium hexaferrites at millimeter wave frequencies

    Science.gov (United States)

    Korolev, Konstantin A.; Wu, Chuanjian; Yu, Zhong; Sun, Ke; Afsar, Mohammed N.; Harris, Vincent G.

    2018-05-01

    Transmittance measurements have been performed on La-Co substituted barium hexaferrites in millimeter waves. Broadband millimeter-wave measurements have been carried out using the free space quasi-optical spectrometer, equipped with a set of high power backward wave oscillators covering the frequency range of 30 - 120 GHz. Strong absorption zones have been observed in the millimeter-wave transmittance spectra of all La-Co substituted barium hexaferrites due to the ferromagnetic resonance. Linear shift of ferromagnetic resonance frequency as functions of La-Co substitutions have been found. Real and imaginary parts of dielectric permittivity of La-Co substituted barium hexaferrites have been calculated using the analysis of recorded high precision transmittance spectra. Frequency dependences of magnetic permeability of La-Co substituted barium hexaferrites, as well as saturation magnetization and anisotropy field have been determined based on Schlömann's theory for partially magnetized ferrites. La-Co substituted barium hexaferrites have been further investigated by DC magnetization to assess magnetic behavior and compare with millimeter wave data. Consistency of saturation magnetization determined independently by both millimeter wave absorption and DC magnetization have been found for all La-Co substituted barium hexaferrites. These materials seem to be quite promising as tunable millimeter wave absorbers, filters, circulators, based on the adjusting of their substitution parameters.

  19. ANALYTICAL EMPLOYMENT OF STABLE ISOTOPES OF CARBON, NITROGEN, OXYGEN AND HYDROGEN FOR FOOD AUTHENTICATION

    Directory of Open Access Journals (Sweden)

    E. Novelli

    2011-04-01

    Full Text Available Stable isotopes of carbon, nitrogen, oxygen and hydrogen were used for analytical purposes for the discrimination of the type of production (farming vs. fishing in the case of sea bass and for geographical origin in the case of milk. These results corroborate similar experimental evidences and confirm the potential of this analytical tool to support of food traceability.

  20. Stable carbon isotope analyses of nanogram quantities of particulate organic carbon (pollen) with laser ablation nano combustion gas chromatography/isotope ratio mass spectrometry

    NARCIS (Netherlands)

    van Roij, Linda; Sluijs, Appy; Laks, Jelmer J.; Reichart, Gert-Jan

    2017-01-01

    Rationale: Analyses of stable carbon isotope ratios (δ13C values) of organic and inorganic matter remains have been instrumental for much of our understanding of present and past environmental and biological processes. Until recently, the analytical window of such analyses has been limited to

  1. Magnesium stable isotope ecology using mammal tooth enamel

    Science.gov (United States)

    Martin, Jeremy E.; Vance, Derek; Balter, Vincent

    2015-01-01

    Geochemical inferences on ancient diet using bone and enamel apatite rely mainly on carbon isotope ratios (δ13C) and to a lesser extent on strontium/calcium (Sr/Ca) and barium/calcium (Ba/Ca) elemental ratios. Recent developments in nontraditional stable isotopes provide an unprecedented opportunity to use additional paleodietary proxies to disentangle complex diets such as omnivory. Of particular relevance for paleodietary reconstruction are metals present in large quantity in bone and enamel apatite, providing that biologically mediated fractionation processes are constrained. Calcium isotope ratios (δ44Ca) meet these criteria but exhibit complex ecological patterning. Stable magnesium isotope ratios (δ26Mg) also meet these criteria but a comprehensive understanding of its variability awaits new isotopic data. Here, 11 extant mammal species of known ecology from a single locality in equatorial Africa were sampled for tooth enamel and, together with vegetation and feces, analyzed for δ26Mg, δ13C, Sr/Ca, and Ba/Ca ratios. The results demonstrate that δ26Mg incorporated in tooth enamel becomes heavier from strict herbivores to omnivores/faunivores. Using data from experimentally raised sheep, we suggest that this 26Mg enrichment up the trophic chain is due to a 26Mg enrichment in muscle relative to bone. Notably, it is possible to distinguish omnivores from herbivores, using δ26Mg coupled to Ba/Ca ratios. The potential effects of metabolic and dietary changes on the enamel δ26Mg composition remain to be explored but, in the future, multiproxy approaches would permit a substantial refinement of dietary behaviors or enable accurate trophic reconstruction despite specimen-limited sampling, as is often the case for fossil assemblages.

  2. Accelerating the transit time of barium sulphate suspensions in small bowel examinations

    International Nuclear Information System (INIS)

    Summers, David S.; Roger, Mark D.; Allan, Paul L.; Murchison, John T.

    2007-01-01

    Purpose: To determine whether hyperosmolar and effervescent agents proven individually to accelerate transit time in the barium small bowel examination have an additive effect when combined, surpassing that of either agent alone. Materials and methods: One hundred and forty-nine patients were randomised to four groups. Three hundred milliliters of barium sulphate alone was given to the first group. Fifteen milliliters of iodinated hyperosmolar contrast agent (Gastrografin, meglumine/sodium diatrizoate, Schering) was given in addition to barium sulphate to the second group while six packets of effervescent granules (Carbex, Ferring) were added for the third group. The final group was given a combination of both additives and barium sulphate. The time taken following ingestion for the contrast column to reach the caecum, as assessed by frequent interval fluoroscopy, was recorded. A subgroup of 32 patients were selected randomly from the four groups, 8 from each and assessed for quality of examination. Statistical assessments were made using Kruskal-Wallis and Mann-Whitney tests. Results: One hundred and nineteen patients were analysed after exclusions. The addition of accelerant to barium sulphate, both individually and in combination significantly reduced the small bowel transit time (p < 0.001). No significant difference existed between the additives when used with barium alone. The combined group had significantly faster transit times compared to the hyperosmolar group (p = 0.02). Differences between combined and effervescent groups tended towards significance (p = 0.09). No significant difference existed between groups when examination quality was assessed. Conclusion: These results suggest that the addition of combined effervescent and hyperosmolar agents to the barium suspension may significantly shorten the small bowel transit time without adversely affecting examination quality. This has implications for patient acceptability of the examination as well as

  3. Study of interferences in the atomic - absorption and emission of barium in nitrous oxide/acetylene flame

    International Nuclear Information System (INIS)

    Curtius, A.J.; Couto, M.I.

    1979-01-01

    The interferences of several ions that are present in oifield water and sea water in the atomic absorption and emission of barium were investigated. It was verified that the interferences of sodium, potassium, calcium, strontium and chloride are the most important. The indirect method for the determination of sulfate by measuring barium by atomic absorption after precipitating barium sulfate with an excess of barium chloride, should not be used for highly salted matrix. To avoid the interferences that are not compensated by an ionization supressor, the measurement of barium by the standard addition method or a previous sulfate separation is recommended. (Author) [pt

  4. On film quality in barium-air double contrast colon study

    International Nuclear Information System (INIS)

    Rhu, Sang Hyung; Rhee, Jae Ho; Kim, Hai Sung; Cheung, Hwan

    1984-01-01

    The colon double contrast study provides valuable diagnostic information by means of appropriate control of Kvp and mAa when making double contrast image by injecting air into the colon after coating the colon wall by appropriately diluted Barium solution. The following experiments were performed the results of which allowed to improve the quality of film in barium-air double contrast colon study: (1) Do the pictures have uniform density when measured with a densitometer from three measuring points established in the picture by changing Kvp and mAs depending on the thickness of the patient? (2) Is the quality of the picture improved by being compensated from the adjacent area when using a wedge filter in routine check lateral decubitus and erect view? (3) What is the optimum dilution of barium solution which gives the best result for colon wall coating? The above experiments revealed that as the patient's thickness increased, it should be considered to increase mAs as well as Kvp and a wedge filter could give diagnostically very informative pictures in routine-check lateral decubitus and erect view. And 70-80% solution of Barium-water mixture provided the best quality of double contrast image

  5. 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.

  6. Barium Isotopes in Single Presolar Grains

    Science.gov (United States)

    Pellin, M. J.; Davis, A. M.; Savina, M. R.; Kashiv, Y.; Clayton, R. N.; Lewis, R. S.; Amari, S.

    2001-01-01

    Barium isotopic compositions of single presolar grains were measured by laser ablation laser resonant ionization mass spectrometry and the implications of the data for stellar processes are discussed. Additional information is contained in the original extended abstract.

  7. Stable carbon and nitrogen isotope variation in the northern lampfish and Neocalanus, marine survival rates of pink salmon, and meso-scale eddies in the Gulf of Alaska

    Science.gov (United States)

    Kline, Thomas C., Jr.

    2010-10-01

    Northern lampfish (NLF), Stenobrachius leucopsarus (Myctophidae), the dominant pelagic fish taxon of the subarctic North Pacific Ocean, were sampled opportunistically in MOCNESS tows made on continental slope waters of the Gulf of Alaska (GOA) as well as in deep areas of Prince William Sound (PWS) during 1997-2006. The overall mean whole-body lipid-corrected stable carbon isotope value of NLF from the GOA was -21.4 (SD = 0.7) whereas that from PWS was -19.5 (SD = 0.9). This pattern is similar to that observed for late feeding stage Neocalanus cristatus copepods thus confirming a mean cross-shelf carbon stable isotope gradient. As well, there was a statistically significant positive correlation between the considerable temporal variation in the monthly mean carbon stable isotope composition of GOA Neocalanus and GOA NLF ( r = 0.69, P food chain length whereas carbon stable isotopes reflect organic carbon production. The carbon stable isotope values of NLF, measured in May, were positively correlated to marine survival rate of PWS hatchery salmon cohorts entering the marine environment the same year ( r = 0.84, P < 0.001). The carbon stable isotope values for Neocalanus in May were also positively correlated to salmon marine survival ( r = 0.82, P < 0.001). Processes thus manifested through the carbon stable isotope value of biota from the continental slope more closely predicted marine survival rate than that of the salmon themselves. The incipient relationships suggested by the correlations are consistent with the hypothesis that exchange between coastal and oceanic waters in the study area is driven by meso-scale eddies. These eddies facilitate the occurrence of slope phytoplankton blooms as well as drive oceanic zooplankton subsidies into coastal waters. The strong as well as more significant correlations of salmon marine survival rate to NLF as well as slope Neocalanus carbon stable isotope values point to processes taking place at the slope (i.e., interactions

  8. Synthesis and characterization of barium ferrite–silica nanocomposites

    International Nuclear Information System (INIS)

    Aguilar-González, M.A.; Mendoza-Suárez, G.; Padmasree, K.P.

    2013-01-01

    In this work, we prepared barium ferrite-silica (BaM-SiO 2 ) nanocomposites of different molar ratios by high-energy ball milling, followed by heat-treatment at different temperatures. The microstructure, morphology and magnetic properties were characterized for different synthesis conditions by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). The results indicate that 15 h of milling was enough to avoid the generation of hematite phase and to get a good dispersion of barium ferrite particles in the ceramic matrix. For milling periods beyond 15 h and heat treatment above 900 °C, the XRD patterns showed the presence of hematite phase caused by the decomposition of BaM. The agglomerate size observed through SEM analysis was around 150 nm with a good BaM dispersion into the SiO 2 matrix. The highest saturation magnetization (Ms) value obtained was 43 emu/g and the corresponding coercivity (Hc) value of 3.4 kOe for the composition 60BaM-40SiO 2 milled for 15 h and heat treated at 900 °C. This coercivity value is acceptable for the application in magnetic recording media. Highlights: • Barium ferrite–silica nanocomposites were prepared by high energy ball milling. • Optimal processing time is 15 h milling and heat treatment at 900 °C. • This is enough to avoid the generation of hematite phase. • Obtain good dispersion of barium ferrite particles in the ceramic matrix • Above this processing time shows the presence of increased amount of hematite

  9. Controlling Barium Sulphate Scale Deposition Problems in an unbleached Kraft Paper Mill

    CSIR Research Space (South Africa)

    Sithole, Bruce

    2015-06-01

    Full Text Available Troubleshooting of scale deposits and defects in paper samples showed that the problem was caused by barium sulphate and calcium sulphate scales. However, it was ascertained that barium sulphate was more of a concern than calcium sulphate...

  10. Development of biomonitoring equivalents for barium in urine and plasma for interpreting human biomonitoring data.

    Science.gov (United States)

    Poddalgoda, Devika; Macey, Kristin; Assad, Henry; Krishnan, Kannan

    2017-06-01

    The objectives of the present work were: (1) to assemble population-level biomonitoring data to identify the concentrations of urinary and plasma barium across the general population; and (2) to derive biomonitoring equivalents (BEs) for barium in urine and plasma in order to facilitate the interpretation of barium concentrations in the biological matrices. In population level biomonitoring studies, barium has been measured in urine in the U.S. (NHANES study), but no such data on plasma barium levels were identified. The BE values for plasma and urine were derived from U.S. EPA's reference dose (RfD) of 0.2 mg/kg bw/d, based on a lower confidence limit on the benchmark dose (BMDL 05 ) of 63 mg/kg bw/d. The plasma BE (9 μg Ba/L) was derived by regression analysis of the near-steady-state plasma concentrations associated with the administered doses in animals exposed to barium chloride dihydrate in drinking water for 2-years in a NTP study. Using a human urinary excretion fraction of 0.023, a BE for urinary barium (0.19 mg/L or 0.25 mg/g creatinine) was derived for US EPA's RfD. The median and the 95 th percentile barium urine concentrations of the general population in U.S. are below the BE determined in this study, indicating that the population exposure to inorganic barium is expected to be below the exposure guidance value of 0.2 mg/kg bw/d. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  11. Severe acute cholangitis after endoscopic sphincterotomy induced by barium examination: A case report.

    Science.gov (United States)

    Zhang, Zhen-Hai; Wu, Ya-Guang; Qin, Cheng-Kun; Su, Zhong-Xue; Xu, Jian; Xian, Guo-Zhe; Wu, Shuo-Dong

    2012-10-21

    Endoscopic sphincterotomy (EST) is considered as a possible etiological factor for severe cholangitis. We herein report a case of severe cholangitis after endoscopic sphincterotomy induced by barium examination. An adult male patient presented with epigastric pain was diagnosed as having choledocholithiasis by ultrasonography. EST was performed and the stone was completely cleaned. Barium examination was done 3 d after EST and severe cholangitis appeared 4 h later. The patient was recovered after treated with tienam for 4 d. Barium examination may induce severe cholangitis in patients after EST, although rare, barium examination should be chosen cautiously. Cautions should be also used when EST is performed in patients younger than 50 years to avoid the damage to the sphincter of Oddi.

  12. Reaction between barium and nitrogen in liquid sodium

    International Nuclear Information System (INIS)

    Addison, C.C.; Pulham, R.J.; Trevillion, E.A.

    1975-01-01

    Nitrogen in increasing amounts has been added to separate solutions of barium in sodium of constant composition (ca.4.40 mol % Ba) at 300 0 C. After rendering each mixture homogenous using an electromagnetic pump, filtration, and nitrogen analysis, all the N 2 added has been found in solution up to a solution composition approximating to Ba 4 N (i.e. 1.1 mol % N) beyond which the quantity of dissolved N 2 decreases progressively due to precipitation of the nitride Ba 2 N. The solubilization is interpreted in terms of strong preferential solvation of the nitride ion by barium cations. (author)

  13. Barium atoms and N20 molecular agregates reaction

    International Nuclear Information System (INIS)

    Visticot, J.P.; Mestdagh, J.M.; Alcaraz, C.; Cuvellier, J.; Berlande, J.

    1988-06-01

    The collisions between a barium atom and N20 molecular agregates are studied, for a better understanding of the solvation part in a chemical reaction. The experiments are carried out in a crossed molecular beam device. The light coming from the collision zone is scattered, and analysed by means of a photon detector. A time-of-flight technique is applied in the investigation of the beam's polymer concentration. The results show a nearly negligible chemiluminescent effect in the reaction between barium and N20 polymer. A solvated BaO formation mechanism is proposed to justify the experimental results [fr

  14. An experimental study on sterilized barium sulfate (BaSO4) for vertebroplasty

    International Nuclear Information System (INIS)

    Chen Long; Ni Caifang; Ding Yi; Wang Yijin

    2005-01-01

    Objective: To search the proper sterilization method of barium for vertebroplasty. Methods: Perfusion agents were classified into two groups with ratio of powder/liquid(g/ml) as 3:2, and the percentage of BsSO 4 in powder was 20%. The barium powder in one group was sterilized by dry-heat and by ethylene oxide in the other. The barium powder of each group was germicultured and the polymerization time, CT value, strength and stiffness were measured respectively including 6 samples. Two independent-samples t text was used for analysis. Results: The germiculture in each group was negative. The difference in polmerization time and CT value of each group were not significant (P>0.05), while the strength and stiffness were significantly different (P<0.05). Conclusions: Sterilized effects of two groups were satisfied but the dry-heat barium sulfate is superior, more suitable for vertebroplasty. (authors)

  15. Interactions between nitrogen molecules and barium atoms on Ru (0001) surface

    International Nuclear Information System (INIS)

    Zhao Xinxin; Mi Yiming; Xu Hongxia; Wang Lili; Ren Li; Tao Xiangming; Tan Mingqiu

    2011-01-01

    We had performed first principles calculations on interactions between nitrogen molecules and barium atoms on Ru (0001) surface using density function theory methods. It was shown that effects of barium atoms weakened the bond strength of nitrogen molecules. The bond length of nitrogen molecule increases from 0.113 nm on Ru (001)-N 2 to 0.120 nm on Ru (001)-N 2 /Ba surface. While stretch vibrational frequency of nitrogen molecule decreased from 2222 cm -1 and charge transfer toward nitrogen molecule increased from 0.3 e to 1.1 e. Charge was mainly translated from 6 s orbitals of barium atoms to 4 d orbitals of substrate, which enhanced the hybridization between 4 d and 2 π orbitals and increased the dipole moment of 5 σ and d π orbitals of nitrogen molecule. The molecular dipole moment of nitrogen molecule was increased by -0.136 e Anstrom. It was suggested that barium had some characters to be an electronic promoter on the process of activating nitrogen molecules on Ru (0001) surface. (authors)

  16. Barium inhibits arsenic-mediated apoptotic cell death in human squamous cell carcinoma cells.

    Science.gov (United States)

    Yajima, Ichiro; Uemura, Noriyuki; Nizam, Saika; Khalequzzaman, Md; Thang, Nguyen D; Kumasaka, Mayuko Y; Akhand, Anwarul A; Shekhar, Hossain U; Nakajima, Tamie; Kato, Masashi

    2012-06-01

    Our fieldwork showed more than 1 μM (145.1 μg/L) barium in about 3 μM (210.7 μg/L) arsenic-polluted drinking well water (n = 72) in cancer-prone areas in Bangladesh, while the mean concentrations of nine other elements in the water were less than 3 μg/L. The types of cancer include squamous cell carcinomas (SCC). We hypothesized that barium modulates arsenic-mediated biological effects, and we examined the effect of barium (1 μM) on arsenic (3 μM)-mediated apoptotic cell death of human HSC-5 and A431 SCC cells in vitro. Arsenic promoted SCC apoptosis with increased reactive oxygen species (ROS) production and JNK1/2 and caspase-3 activation (apoptotic pathway). In contrast, arsenic also inhibited SCC apoptosis with increased NF-κB activity and X-linked inhibitor of apoptosis protein (XIAP) expression level and decreased JNK activity (antiapoptotic pathway). These results suggest that arsenic bidirectionally promotes apoptotic and antiapoptotic pathways in SCC cells. Interestingly, barium in the presence of arsenic increased NF-κB activity and XIAP expression and decreased JNK activity without affecting ROS production, resulting in the inhibition of the arsenic-mediated apoptotic pathway. Since the anticancer effect of arsenic is mainly dependent on cancer apoptosis, barium-mediated inhibition of arsenic-induced apoptosis may promote progression of SCC in patients in Bangladesh who keep drinking barium and arsenic-polluted water after the development of cancer. Thus, we newly showed that barium in the presence of arsenic might inhibit arsenic-mediated cancer apoptosis with the modulation of the balance between arsenic-mediated promotive and suppressive apoptotic pathways.

  17. Porous one-dimensional carbon/iron oxide composite for rechargeable lithium-ion batteries with high and stable capacity

    International Nuclear Information System (INIS)

    Zhu, Jiadeng; Lu, Yao; Chen, Chen; Ge, Yeqian; Jasper, Samuel; Leary, Jennifer D.; Li, Dawei; Jiang, Mengjin; Zhang, Xiangwu

    2016-01-01

    Hematite iron oxide (α-Fe_2O_3) is considered to be a prospective anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity (1007 mAh g"−"1), nontoxicity, and low cost. However, the low electrical conductivity and large volume change during Li insertion/extraction of α-Fe_2O_3 hinder its use in practical batteries. In this study, carbon-coated α-Fe_2O_3 nanofibers, prepared via an electrospinning method followed by a thermal treatment process, are employed as the anode material for LIBs. The as-prepared porous nanofibers with a carbon content of 12.5 wt% show improved cycling performance and rate capability. They can still deliver a high and stable capacity of 715 mAh g"−"1 even at superior high current density of 1000 mA g"−"1 after 200 cycles with a large Coulombic efficiency of 99.2%. Such improved electrochemical performance can be assigned to their unique porous fabric structure as well as the conductive carbon coating which shorten the distance for Li ion transport, enhancing Li ion reversibility and kinetic properties. It is, therefore, demonstrated that carbon-coated α-Fe_2O_3 nanofiber prepared under optimized conditions is a promising anode material candidate for LIBs. - Graphical abstract: Carbon-coated α-Fe_2O_3 nanofibers are employed as anode material to achieve high and stable electrochemical performance for lithium-ion batteries, enhancing their commercial viability. - Highlights: • α-Fe_2O_3/C nanofibers were fabricated by electrospinning and thermal treatment. • α-Fe_2O_3/C nanofibers exhibit stable cyclability and good rate capability. • α-Fe_2O_3–C nanofibers maintain high capacity at 1000 mA g"−"1 for 200 cycles. • A capacity retention of 99.2% is achieved by α-Fe_2O_3–C nanofibers after 200 cycles.

  18. Using stable isotopes of carbon and nitrogen as in-situ tracers for monitoring the natural attenuation of explosives

    National Research Council Canada - National Science Library

    Miyares, Paul H

    1999-01-01

    The use of carbon and nitrogen stable isotope measurements from TNT was examined as a possible tool for monitoring the natural attenuation of TNT incubation studies of spiked soil samples were conducted...

  19. M series resonant x-ray lines of barium for near threshold electron excitation

    International Nuclear Information System (INIS)

    Morgon, D.V.

    1992-01-01

    An investigation of the M series resonant x-ray emission lines of barium for near threshold electron excitation was undertaken with a vacuum double crystal spectrometer equipped with potassium acid phthalate crystals. X-ray continuum isochromats were obtained for barium samples using the double crystal spectrometer as a monochrometer set to pass 532 eV photons. The rotatable anode allowed the samples to be observed by either the double crystal spectrometer or a soft x-ray appearance potential spectrometer, which was used for monitoring the surface of the varium sample for contamination, and to provide a cross-check for the double crystal spectrometer data. Barium M series characteristic x-ray spectra for 2.0 keV electron excitation were obtained for a variety of samples, and it was discovered that the fluorescent and resonant x-ray emission line energies remained virtually the same, regardless of the chemical condition of the sample. The continuum resonance effect was observed for near-threshold energy electron excitation, but it was significantly weaker than the same effect observed previously for lanthanum or cerium. The electron excitation energy and intensity of this effect were strongly dependent on the chemical condition of the barium sample. X-ray continuum isochromats were observed for pure and contaminated barium samples at a photon energy of 532 eV. For pure metallic barium, a peak associated with 4f electronic states was observed at an energy of about 10.2 eV above the Fermi level. When the sample was exposed to 1.5 x 10 4 Langmuir of air, the 4f structure became more sharply peaked, and shifted to an energy of about 12.0 eV above the Fermi level. A continuum isochromat of barium oxide was also observed. Chemical shifts in barium M IV and M V appearance potential spectra are therefore caused soley by shifts in the energy position of the empty 4f electronic states relative to the Fermi level

  20. Modified small bowel follow-through using methylcellulose after administration of barium suspension : comparison with conventional series

    International Nuclear Information System (INIS)

    Shin, Ji Hoon; Ha, Hyun Kwon; Park, Sung Tae; Yoon, Soo Woong; Kim, Ho Sung; Kim, Sun Mi

    1998-01-01

    To compare modified small bowel follow-through (SBFT) using methylcellulose after the administration of barium suspension with a conventional series. Materials and Methods : In order to evaluate small bowel pathology, modified SBFT was performed in 155 patients during a 15 month period. All patients received 600 mL of methylcellulose ; 98 had taken 250 mL of 40% wt/vol barium suspension and 57 had taken 150 mL of 70% barium. For the group of 98, the barium suspension was prepared by mixing barium powder with water (n=46) or with methylcellulose in(n=52). For comparison with a modified series, 49 patients who underwent conventional SBFT using 500 mL of 40 %wt/vol barium were lso included. Image quality was rated by three radiologists as p oor , f air , g ood , or e xcellent . We analyzed the relationship between image quality, transit time and small bowel pathology;the sensitivity and specificity of each technique was also determined. Results : Among the four techniques, modified SBFT with 250 mL of 40% wt/vol barium suspension, prepared by mixing barium powder with methylcellulose, showed the best image quality ['excellent' result in 33 of the 52 patients (63%)] and shortest transit time to the cecum. The high image quality of this technique was not affected by the presence of small bowel pathology;its use resulted in the lowest incidence and slowest development of flocculation. The sensitivity (91-95%) of the three modified SBFT procedures was superior to that of a conventional series(76%), but there was no difference in specificity.Conclusion : Modified SBFT using methylcellulose after administering barium suspension with barium powder as a mixing agent is a simple technique. Its use easily improves the image quality and diagnostic accuracy of peroral SBFT

  1. Radiologic diagnosis of gastro-oesophageal reflux. Comparison of barium and low-density contrast medium

    Energy Technology Data Exchange (ETDEWEB)

    Fransson, S.G.; Soekjer, H.; Johansson, K.E.; Tibbling, L.

    It has been proposed that the high density of ordinary barium suspension may complicate the radiologic diagnosis of gastro-oesophageal reflux. For this reason P-contrast was developed (Ferring AB); a contrast medium with the same density as water (1 g/cm/sup 3/). A comparison of P-contrast and barium (Mixobar Ventrikel 400 mg/ml) was performed in 82 patients. All patients were examined with both contrast media and the findings were compared with those at reflux test at manometry, endoscopy and 24-hour pH monitoring. Another 40 patients and 15 symptom-free controls were examined with two different amounts of barium, 100 ml and 200 ml, to study if the radiologic diagnosis of reflux varied with the volume of contrast medium administered. P-contrast was found to have no advantages over barium for the diagnosis of gastro-oesophageal reflux. The outcome of the radiologic examination was not influenced by the different volumes of barium used.

  2. Anion and cation diffusion in barium titanate and strontium titanate; Anionen- und Kationendiffusion in Barium- und Strontiumtitanat

    Energy Technology Data Exchange (ETDEWEB)

    Kessel, Markus Franz

    2012-12-19

    Perovskite oxides show various interesting properties providing several technical applications. In many cases the defect chemistry is the key to understand and influence the material's properties. In this work the defect chemistry of barium titanate and strontium titanate is analysed by anion and cation diffusion experiments and subsequent time-of-flight secondary ion mass spectrometry (ToF-SIMS). The reoxidation equation for barium titanate used in multi-layer ceramic capacitors (MLCCs) is found out by a combination of different isotope exchange experiments and the analysis of the resulting tracer diffusion profiles. It is shown that the incorporation of oxygen from water vapour is faster by orders of magnitude than from molecular oxygen. Chemical analysis shows the samples contain various dopants leading to a complex defect chemistry. Dysprosium is the most important dopant, acting partially as a donor and partially as an acceptor in this effectively acceptor-doped material. TEM and EELS analysis show the inhomogeneous distribution of Dy in a core-shell microstructure. The oxygen partial pressure and temperature dependence of the oxygen tracer diffusion coefficients is analysed and explained by the complex defect chemistry of Dy-doped barium titanate. Additional fast diffusion profiles are attributed to fast diffusion along grain boundaries. In addition to the barium titanate ceramics from an important technical application, oxygen diffusion in cubic, nominally undoped BaTiO{sub 3} single crystals has been studied by means of {sup 18}O{sub 2}/{sup 16}O{sub 2} isotope exchange annealing and subsequent determination of the isotope profiles in the solid by ToF-SIMS. It is shown that a correct description of the diffusion profiles requires the analysis of the diffusion through the surface space-charge into the material's bulk. Surface exchange coefficients, space-charge potentials and bulk diffusion coefficients are analysed as a function of oxygen partial

  3. Radioactivity measurement of barium carbonate [14C] by liquid scintillation counting

    International Nuclear Information System (INIS)

    Kobayashi, Katsutoshi; Hoizumi, Kiyoshi

    1985-03-01

    Two methods of sample preparation for the measurement of specific activity of BaCO 3 [ 14 C] by external standard method in liquid scintillation counting were studied. BaCO 3 [ 14 C] was decomposed by perchloric acid solution and generated CO 2 [ 14 C] was absorbed by ethylene glycol monomethyl ether solution of monoethanolamine as the method 1 or aqueous sodium hydroxide as the method 2. In order to prepare the sample solution of adequate radioactivity concentration, these carbonate solutions by the methods 1 and 2 were diluted with the suitable organic solvent and distilled water respectively. One tenth millilitre of these sample solutions was added into 10 ml of PPO-toluene scintillator containing 0.1 ml of monoethanolamine in a counting vial and homogeneously dissolved with ethyl alcohol. The results of the radioactivity measurement of BaCO 3 [ 14 C] based on the different method agreed within 5 % and the counting rate was found to be stable for as long as 7 deays or more. Both methods of preparation are suitable for the routine measurement because of their simplicity and feasibility. In the case of method 2, the liquid radioactive waste is almost inorganic solution and recovery in the form of BaCO 3 [ 14 C] is easily performed, so that this method is very advantageous from the view point of the radioactive waste treatement. (author)

  4. Impurities in barium titanate posistor ceramics

    Czech Academy of Sciences Publication Activity Database

    Korniyenko, S. M.; Bykov, I. P.; Glinchuk, M. J.; Laguta, V. V.; Belous, A. G.; Jastrabík, Lubomír

    2000-01-01

    Roč. 239, - (2000), s. 1209-1218 ISSN 0015-0193 Institutional research plan: CEZ:AV0Z1010914 Keywords : barium titanate phase transition * ESR * positive temperature coefficient of resistivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.547, year: 2000

  5. The stable carbon isotope ratios in benthic food webs of the gulf of Calvi, Corsica

    Science.gov (United States)

    Dauby, Patrick

    1989-02-01

    The Gulf of Calvi, Corsica, presents a wide diversity of biocoenoses, amongst which the seagrass Posidonia meadow is prevalent. More than 100 plant, animal and sediment samples from various biotopes were analysed for their stable carbon isotope ratios, to assess carbon flows within the food chains. Marine plants display a wide range of δ 13C values, from -6 to -32‰ but with three relatively well distinct peaks for Posidonia, brown algae and phytoplankton (-9, -19 and -23‰, respectively), which are the main carbon sources. The range of isotopic values of animals is narrower, from -14 to -24‰, suggesting that they feed mainly on algae and plankton. Computations based on simple equations show the proportion of each carbon source in the diet of the animals. Posidonia, notwithstanding their important biomass, appear to be a minor food source; this is possibly because of the transfer of their dead leaves, towards the shorelines, in winter.

  6. Gastroesophageal reflux: comparison of barium studies with 24-h pH monitoring

    International Nuclear Information System (INIS)

    Pan, John J.; Levine, Marc S.; Redfern, Regina O.; Rubesin, Stephen E.; Laufer, Igor; Katzka, David A.

    2003-01-01

    Objective: To determine the correlation between massive gastroesophageal reflux (GER) on barium studies and pathologic acid reflux on 24-h pH monitoring. Methods: A search of hospital records from January 1997 to January 2001 revealed 28 patients who underwent both barium studies and 24-h pH monitoring. The radiologic reports were reviewed to determine the presence and degree of GER. Patients with reflux to or above the thoracic inlet either spontaneously or with provocative maneuvers in the recumbent position were classified as having massive reflux, whereas the remaining patients with reflux below the thoracic inlet or no reflux comprised the control group. The pH monitoring reports were also reviewed to determine if pathologic acid reflux was present in the recumbent position. The findings on these studies were then compared to determine the frequency of pathologic acid reflux in the recumbent position on pH monitoring in patients with massive reflux on barium studies compared with the control group. Results: Massive GER was observed on barium studies in 11 (39%) of the 28 patients and reflux below the thoracic inlet or no reflux in the remaining 17 patients (61%) who comprised the control group. All 11 patients (100%) with massive reflux on barium studies had pathologic acid reflux on pH monitoring in the recumbent position compared with six (35%) of 17 patients in the control group (P=0.0009). The pH in the distal esophagus on pH monitoring was less than 4.0 for 13.1% of the recumbent period for patients with massive GER on barium studies compared with 6.2% of the recumbent period for the control group (P=0.0076). Conclusion: Although 24-h pH monitoring remains the gold standard for the detection of GER, our experience suggests that patients with massive reflux on barium studies are so likely to have pathologic acid reflux in the recumbent position that these individuals can be further evaluated and treated for their gastroesophageal reflux disease (GERD

  7. Gastroesophageal reflux: comparison of barium studies with 24-h pH monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Pan, John J.; Levine, Marc S. E-mail: levine@oasis.rad.upenn.edu; Redfern, Regina O.; Rubesin, Stephen E.; Laufer, Igor; Katzka, David A

    2003-08-01

    Objective: To determine the correlation between massive gastroesophageal reflux (GER) on barium studies and pathologic acid reflux on 24-h pH monitoring. Methods: A search of hospital records from January 1997 to January 2001 revealed 28 patients who underwent both barium studies and 24-h pH monitoring. The radiologic reports were reviewed to determine the presence and degree of GER. Patients with reflux to or above the thoracic inlet either spontaneously or with provocative maneuvers in the recumbent position were classified as having massive reflux, whereas the remaining patients with reflux below the thoracic inlet or no reflux comprised the control group. The pH monitoring reports were also reviewed to determine if pathologic acid reflux was present in the recumbent position. The findings on these studies were then compared to determine the frequency of pathologic acid reflux in the recumbent position on pH monitoring in patients with massive reflux on barium studies compared with the control group. Results: Massive GER was observed on barium studies in 11 (39%) of the 28 patients and reflux below the thoracic inlet or no reflux in the remaining 17 patients (61%) who comprised the control group. All 11 patients (100%) with massive reflux on barium studies had pathologic acid reflux on pH monitoring in the recumbent position compared with six (35%) of 17 patients in the control group (P=0.0009). The pH in the distal esophagus on pH monitoring was less than 4.0 for 13.1% of the recumbent period for patients with massive GER on barium studies compared with 6.2% of the recumbent period for the control group (P=0.0076). Conclusion: Although 24-h pH monitoring remains the gold standard for the detection of GER, our experience suggests that patients with massive reflux on barium studies are so likely to have pathologic acid reflux in the recumbent position that these individuals can be further evaluated and treated for their gastroesophageal reflux disease (GERD

  8. CMI Remedy Selection for HE- and Barium-Contaminated Vadose Zone and Alluvium at LANL

    Science.gov (United States)

    Hickmott, D.; Reid, K.; Pietz, J.; Ware, D.

    2008-12-01

    A high explosives (HE) machining building outfall at Los Alamos National Laboratory's Technical Area 16 discharged millions of gallons of HE- and barium-contaminated water into the Canon de Valle watershed. The effluent contaminated surface soils, the alluvial aquifer, vadose zone waters, and deep-perched and regional groundwaters with HE and barium, frequently at levels greater than regulatory standards. Site characterization studies began in 1995 and included extensive monitoring of surface water, groundwater, soils, and subsurface solid media. Hydrogeologic and geophysical studies were conducted to help understand contaminant transport mechanisms and pathways. Results from the characterization studies were used to develop a site conceptual model. In 2000 the principal source area was removed. The ongoing Corrective Measure Study (CMS) and Corrective Measure Implementation (CMI) focus on residual vadose zone contamination and on the contaminated alluvial system. Regulators recently selected a CMI remedy that combined: 1) augmented source removal; 2) grouting of an HE- contaminated surge bed; 3) deployment of Stormwater Management System (SMS) stormfilters in contaminated springs; and 4) permeable reactive barriers (PRBs) in contaminated alluvium. The hydrogeologic conceptual model for the vadose zone and alluvial system as well as the status of the canyon as habitat for the Mexican Spotted Owl were key factors in selection of these minimal-environmental-impact remedies. The heterogeneous vadose zone, characterized by flow and contaminant transport in fractures and in surge beds, requires contaminant treatment at a point of discharge. The canyon PRB is being installed to capture water and contaminants prior to infiltration into the vadose zone. Pilot-scale testing of the SMS and lab-scale batch and column tests of a range of media suggest that granular activated carbon, zeolite, and gypsum may be effective media for removal of HE and/or barium from contaminated

  9. The synthesis of tritium, carbon-14 and stable isotope labelled selective estrogen receptor degraders.

    Science.gov (United States)

    Bragg, Ryan A; Bushby, Nick; Ericsson, Cecilia; Kingston, Lee P; Ji, Hailong; Elmore, Charles S

    2016-09-01

    As part of a Medicinal Chemistry program aimed at developing an orally bioavailable selective estrogen receptor degrader, a number of tritium, carbon-14, and stable isotope labelled (E)-3-[4-(2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-yl)phenyl]prop-2-enoic acids were required. This paper discusses 5 synthetic approaches to this compound class. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Barium and manganese-doped zinc silicate rods prepared by mesoporous template route and their luminescence property

    Science.gov (United States)

    Dang, Lingyan; Tian, Chen; Zhao, Shifeng; Lu, Qingshan

    2018-06-01

    Barium and manganese-doped zinc silicates was prepared under hydrothermal treatment by mesoporous template route employing mesoporous silica as an active template. The sample displays a rod-like morphology with a mean diameter of ∼40 nm and a mean length of ∼450 nm, which inherits the characteristics of mesoporous silica. The individual rods show single crystalline and assemble into bundle-like hierarchical structure along the channels of the mesoporous silica. When barium ions together with manganese ions are co-doped in zinc silicate, the green emission corresponding to manganese ions display a significant enhancement, especially for the sample with the barium doping concentration of 0.08, which indicates that an energy transfer from barium to manganese ions takes place. With further increasing barium concentration from 0.08 to 0.10, the recombination between the defects related to barium and the excitation states of the manganese dominates accompanying non-radiative transitions which can reduce the emission efficiency.

  11. Authigenic carbonates from newly discovered active cold seeps on the northwestern slope of the South China Sea: Constraints on fluid sources, formation environments, and seepage dynamics

    Science.gov (United States)

    Liang, Qianyong; Hu, Yu; Feng, Dong; Peckmann, Jörn; Chen, Linying; Yang, Shengxiong; Liang, Jinqiang; Tao, Jun; Chen, Duofu

    2017-06-01

    Authigenic carbonates recovered from two newly discovered active cold seeps on the northwestern slope of the South China Sea have been studied using petrography, mineralogy, stable carbon and oxygen isotopic, as well as trace element compositions, together with AMS 14C ages of shells of seep-dwelling bivalves to unravel fluid sources, formation conditions, and seepage dynamics. The two seeps (ROV1 and ROV2), referred to as 'Haima seeps' herein, are approximately 7 kilometers apart, and are typified by abundant carbonate rocks represented bycrusts and nodules. Aragonite and high-Mg calcite are the main carbonate minerals. Based on low δ13Ccarbonate values ranging from -43.0‰ to -27.5‰ (V-PDB) methane is apparently the predominant carbon source of seep carbonates. The corresponding δ18O values, varying from 2.5‰ to 5.8‰ (V-PDB), mostly are higher than calculated values representing precipitation in equilibrium with seawater (2.5‰ to 3.8‰), which probably reflects past destabilization of locally abundant gas hydrates. In addition, we found that carbonates with bivalve shells are generally aragonite-dominated, and bear no barium enrichment but uranium enrichments, reflecting shallow formation depths close to the seafloor. In contrast, carbonate crusts without bivalve shells and nodules contain more calcite, and are characterized by major molybdenum enrichment and different degrees of barium enrichment, agreeing with precipitation at greater depth under strictly anoxic conditions. AMS 14C ages suggest that a major episode of carbonate precipitation occurred between 6.1 ka and 5.1 ka BP at the Haima seeps, followed by a possibly subordinate episode from approximately 3.9 ka to 2.9 ka BP. The common occurrence of dead bivalves at both sites indicates that chemosynthesis-based communities flourished to a greater extent in the past, probably reflecting a decline of seepage activity in recent times. Overall, these results confirm that authigenic carbonates from

  12. Electronic and chemical properties of barium and indium clusters

    International Nuclear Information System (INIS)

    Onwuagba, B.N.

    1992-11-01

    The ground state electronic and chemical properties of divalent barium and trivalent indium are investigated in a self-consistent manner using the spin-polarized local density approximation in the framework of Density Functional Theory. A jellium model is adopted in the spirit of Gunnarsson and Lundqvist exchange and correlation energies and the calculated properties primarily associated with the s-p orbitals in barium and p orbitals in indium provide deepened insight towards the understanding of the mechanisms to the magic numbers in both clusters. (author). 21 refs, 5 figs

  13. Preparation and characterization of antimony barium composite oxide photocatalysts

    Science.gov (United States)

    Han, X. P.; Yao, B. H.; Pan, Q. H.; Pen, C.; Zhang, C. L.

    2018-01-01

    In this paper, two kinds of antimony barium composite oxide photocatalysts have been prepared by two methods and characterized by XRD and SEM. The photocatalytic activity was evaluated by a photocatalytic reactor and an ultraviolet spectrophotometer. The results showed that-BaSb2O5•4H2O, BaSb2O6 two kinds of antimony barium composite oxide photocatalysts were successfully prepared in this experiment and they showed good photocatalytic properties. In addition, BaSb2O6 morphology showed more regular, microstructure and better catalytic performance.

  14. Carbon and nitrogen stable isotope ratios of pelagic zooplankton elucidate ecohydrographic features in the oligotrophic Red Sea

    KAUST Repository

    Kü rten, Benjamin; Al-Aidaroos, Ali M.; Kurten, Saskia; El-Sherbiny, Mohsen M.; Devassy, Reny P.; Struck, Ulrich; Zarokanellos, Nikolaos; Jones, Burton; Hansen, Thomas; Bruss, Gerd; Sommer, Ulrich

    2015-01-01

    Although zooplankton occupy key roles in aquatic biogeochemical cycles, little is known about the pelagic food web and trophodynamics of zooplankton in the Red Sea. Natural abundance stable isotope analysis (SIA) of carbon (δ13C) and N (δ15N) is one

  15. Comparison of stable carbon isotope ratios in the whole wood, cellulose and lignin of Oak tree-rings

    CSIR Research Space (South Africa)

    Loader, NJ

    2003-08-01

    Full Text Available The stable carbon isotope ratios (N13C) of whole wood, cellulose and acid-insoluble lignin from annual latewood increments of Quereus robur L., from modern and sub-fossil wood, were measured and their potential use as palaeo environmental indicators...

  16. Using stable isotopes of nitrogen and carbon to study seabird ecology: applications in the Mediterranean seabird community

    Directory of Open Access Journals (Sweden)

    Manuela G. Forero

    2003-07-01

    Full Text Available The application of the stable isotope technique to ecological studies is becoming increasingly widespread. In the case of seabirds, stable isotopes of nitrogen and carbon have been mainly used as dietary tracers. This approach relieson the fact that food web isotopic signatures are reflected in the tissues of the consumer. In addition to the study of trophic ecology, stable isotopes have been used to track the movement of seabirds across isotopic gradients, as individuals moving between isotopically distinct foodwebs can carry with them information on the location of previous feeding areas. Studies applying the stable isotope methodology to the study of seabird ecology show a clear evolution from broad and descriptive approaches to detailed and individual-based analyses. The purpose of this article is to show the different fields of application of stable isotopes to the study of the seabird ecology. Finally, we illustrate the utility of this technique by considering the particularities of the Mediterranean seabird community, suggesting different ecological questions and conservation problems that could be addressed by using the stable isotope approach in this community.

  17. Preparation and properties of yttria doped tetragonal zirconia polycrystal/Sr-doped barium hexaferrite ceramic composites

    International Nuclear Information System (INIS)

    Wang, Shanshan; Zhang, Chao; Guo, Ruisong; Liu, Lan; Yang, Yuexia; Li, Kehang

    2015-01-01

    Highlights: • The 3Y-TZP/Sr-doped barium ferrite composites were prepared. • The saturation magnetization was improved by 15% with Sr-doping. • The dispersion coefficient p could reflect the microscopic lattice variation. • The composite with x = 0.5 had the maximum fracture toughness of 8.3 MPa m 1/2 . - Abstract: The effects of substitution of Ba 2+ by Sr 2+ on the magnetic property of barium ferrite and addition barium ferrite secondary phase to the 3 mol% yttria-doped tetragonal zirconia polycrystal (3Y-TZP) matrix on the mechanical property of composites were investigated. The Sr-doped barium ferrite (Ba 1−x Sr x Fe 12 O 19 , x = 0, 0.25, 0.50 and 0.75) was synthesized by solid-state reaction in advance. Then 3Y-TZP/20 wt% Sr-doped barium ferrite composites were prepared by means of conventional ceramic method. It was found that a moderate amount of Sr added to barium ferrite could boost the saturation magnetization by 15% compared with the composites without Sr-doping. Besides, the composite with x = 0.50 possessed the best mechanical properties, such as 11.5 GPa for Vickers hardness and 8.3 MPa m 1/2 for fracture toughness, respectively. It was demonstrated that magnetic and mechanical properties of the composites could be harmonized by the incorporation of barium ferrite secondary phase

  18. Measurements of barium photocathode quantum yields at four excimer laser wavelengths

    International Nuclear Information System (INIS)

    Van Loy, M.D.; Young, A.T.; Leung, K.N.

    1992-06-01

    The electron quantum yields from barium cathodes excited by excimer laser radiation at 193, 248, 308, and 351 nm have been determined. Experiments with different cathode surface preparation techniques reveal that deposition of barium film a few microns thick on a clean copper surface under moderate vacuum conditions achieves relatively high quantum efficiencies. Quantum yields measured from surfaces prepared in this manner are 2.3 x 10 -3 at 193 nm, 7.6 x 10 - 4 at 248 nm, 6.1 x 10 -4 at 308 nm, and 4.0 x 10 -4 at 351 nm. Other preparation techniques, such as laser cleaning of a solid barium surface, produced quantum yields that were at least an order of magnitude lower than these values

  19. Carbon dioxide effects research and assessment program. Proceedings of the International Meeting on Stable Isotopes in Tree-Ring Research, New Paltz, New York, May 22-25, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Jacoby, G [ed.

    1980-12-01

    Information about the past and present concentrations of CO/sub 2/ in the atmosphere and variations in climate can be obtained from measurements of stable isotopes in tree rings; specifically carbon-13, oxygen-18 and deuterium. The analysis of these stable isotopes in tree rings is a relatively new and rapidly developing field. This proceedings volume contains most of the papers presented at the meeting. The first paper gives an overview of the status of carbon-13 research. Papers relating to carbon-13 are in section I and grouped separately from the contributions on carbon-14. Although the meeting was primarily concerned with stable isotopes, all carbon isotopic analysis may be helpful in understanding the carbon-13 record in tree rings. The papers on hydrogen and oxygen isotope studies are in sections II and III respectively. The remaining sections contain papers that consider more than one isotope at a time, general topics related to isotopes, atmospheric changes and tree growth, and methods of isotopic analysis.

  20. Automated determination of the stable carbon isotopic composition (δ13C) of total dissolved inorganic carbon (DIC) and total nonpurgeable dissolved organic carbon (DOC) in aqueous samples: RSIL lab codes 1851 and 1852

    Science.gov (United States)

    Révész, Kinga M.; Doctor, Daniel H.

    2014-01-01

    The purposes of the Reston Stable Isotope Laboratory (RSIL) lab codes 1851 and 1852 are to determine the total carbon mass and the ratio of the stable isotopes of carbon (δ13C) for total dissolved inorganic carbon (DIC, lab code 1851) and total nonpurgeable dissolved organic carbon (DOC, lab code 1852) in aqueous samples. The analysis procedure is automated according to a method that utilizes a total carbon analyzer as a peripheral sample preparation device for analysis of carbon dioxide (CO2) gas by a continuous-flow isotope ratio mass spectrometer (CF-IRMS). The carbon analyzer produces CO2 and determines the carbon mass in parts per million (ppm) of DIC and DOC in each sample separately, and the CF-IRMS determines the carbon isotope ratio of the produced CO2. This configuration provides a fully automated analysis of total carbon mass and δ13C with no operator intervention, additional sample preparation, or other manual analysis. To determine the DIC, the carbon analyzer transfers a specified sample volume to a heated (70 °C) reaction vessel with a preprogrammed volume of 10% phosphoric acid (H3PO4), which allows the carbonate and bicarbonate species in the sample to dissociate to CO2. The CO2 from the reacted sample is subsequently purged with a flow of helium gas that sweeps the CO2 through an infrared CO2 detector and quantifies the CO2. The CO2 is then carried through a high-temperature (650 °C) scrubber reactor, a series of water traps, and ultimately to the inlet of the mass spectrometer. For the analysis of total dissolved organic carbon, the carbon analyzer performs a second step on the sample in the heated reaction vessel during which a preprogrammed volume of sodium persulfate (Na2S2O8) is added, and the hydroxyl radicals oxidize the organics to CO2. Samples containing 2 ppm to 30,000 ppm of carbon are analyzed. The precision of the carbon isotope analysis is within 0.3 per mill for DIC, and within 0.5 per mill for DOC.

  1. Photometric Calibration of the Barium Cloud Image in a Space Active Experiment: Determining the Release Efficiency

    International Nuclear Information System (INIS)

    Xie Liang-Hai; Li Lei; Wang Jing-Dong; Tao Ran; Cheng Bing-Jun; Zhang Yi-Teng

    2014-01-01

    The barium release experiment is an effective method to explore the near-earth environment and to study all kinds of space physics processes. The first space barium release experiment in China was successfully carried out by a sounding rocket on April 5, 2013. This work is devoted to calculating the release efficiency of the barium release by analyzing the optical image observed during the experiment. First, we present a method to calibrate the images grey value of barium cloud with the reference stars to obtain the radiant fluxes at different moments. Then the release efficiency is obtained by a curve fitting with the theoretical evolution model of barium cloud. The calculated result is basically consistent with the test value on ground

  2. CT-Guided Percutaneous Transthoracic Localization of Pulmonary Nodules Prior to Video-Assisted Thoracoscopic Surgery Using Barium Suspension

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Nyoung Keun; Park, Chang Min; Kang, Chang Hyun; Jeon, Yoon Kyung; Choo, Ji Yung; Lee, Hyun Ju; Goo, Jin Mo [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2012-11-15

    To describe our initial experience with CT-guided percutaneous barium marking for the localization of small pulmonary nodules prior to video-assisted thoracoscopic surgery (VATS). From October 2010 to April 2011, 10 consecutive patients (4 men and 6 women; mean age, 60 years) underwent CT-guided percutaneous barium marking for the localization of 10 small pulmonary nodules (mean size, 7.6 mm; range, 3-14 mm): 6 pure ground-glass nodules, 3 part-solid nodules, and 1 solid nodule. A 140% barium sulfate suspension (mean amount, 0.2 mL; range, 0.15-0.25 mL) was injected around the nodules with a 21-gauge needle. The technical details, surgical findings and pathologic features associated with barium localizations were evaluated. All nodules were marked within 3 mm (mean distance, 1.1 mm; range, 0-3 mm) from the barium ball (mean diameter, 9.6 mm; range, 8-16 mm) formed by the injected barium suspension. Pneumothorax occurred in two cases, for which one needed aspiration. However, there were no other complications. All barium balls were palpable during VATS and visible on intraoperative fluoroscopy, and were completely resected. Both the whitish barium balls and target nodules were identifiable in the frozen specimens. Pathology revealed one invasive adenocarcinoma, five adenocarcinoma-in-situ, two atypical adenomatous hyperplasias, and two benign lesions. In all cases, there were acute inflammations around the barium balls which did not hamper the histological diagnosis of the nodules. CT-guided percutaneous barium marking can be an effective, convenient and safe pre-operative localization procedure prior to VATS, enabling accurate resection and diagnosis of small or faint pulmonary nodules.

  3. CT-Guided Percutaneous Transthoracic Localization of Pulmonary Nodules Prior to Video-Assisted Thoracoscopic Surgery Using Barium Suspension

    International Nuclear Information System (INIS)

    Lee, Nyoung Keun; Park, Chang Min; Kang, Chang Hyun; Jeon, Yoon Kyung; Choo, Ji Yung; Lee, Hyun Ju; Goo, Jin Mo

    2012-01-01

    To describe our initial experience with CT-guided percutaneous barium marking for the localization of small pulmonary nodules prior to video-assisted thoracoscopic surgery (VATS). From October 2010 to April 2011, 10 consecutive patients (4 men and 6 women; mean age, 60 years) underwent CT-guided percutaneous barium marking for the localization of 10 small pulmonary nodules (mean size, 7.6 mm; range, 3-14 mm): 6 pure ground-glass nodules, 3 part-solid nodules, and 1 solid nodule. A 140% barium sulfate suspension (mean amount, 0.2 mL; range, 0.15-0.25 mL) was injected around the nodules with a 21-gauge needle. The technical details, surgical findings and pathologic features associated with barium localizations were evaluated. All nodules were marked within 3 mm (mean distance, 1.1 mm; range, 0-3 mm) from the barium ball (mean diameter, 9.6 mm; range, 8-16 mm) formed by the injected barium suspension. Pneumothorax occurred in two cases, for which one needed aspiration. However, there were no other complications. All barium balls were palpable during VATS and visible on intraoperative fluoroscopy, and were completely resected. Both the whitish barium balls and target nodules were identifiable in the frozen specimens. Pathology revealed one invasive adenocarcinoma, five adenocarcinoma-in-situ, two atypical adenomatous hyperplasias, and two benign lesions. In all cases, there were acute inflammations around the barium balls which did not hamper the histological diagnosis of the nodules. CT-guided percutaneous barium marking can be an effective, convenient and safe pre-operative localization procedure prior to VATS, enabling accurate resection and diagnosis of small or faint pulmonary nodules.

  4. Stable carbon and oxygen isotope studies of Late Weichselian lake sediments in southern Sweden and northern Poland, with palaeoclimatic implications

    International Nuclear Information System (INIS)

    Hammarlund, D.

    1994-04-01

    Late Weichselian lacustrine sediment sequences from southern Sweden and northern Poland were studied by means of stable isotope analysis in order to reconstruct the climatic development and climatically induced environmental changes in the respective regions. The methods used include analyses of the stable carbon isotope composition (δ 13 C) of bulk organic material, and the stable carbon and oxygen isotope compositions (δ 13 C, δ 18 O) of bulk carbonates and carbonate shells of aquatic organisms. These results were complemented and supported by lithological, chemical and biostratigraphic data (plant macrofossils, insects, molluscs). Chronological data were obtained by AMS radiocarbon dates and correlations based on pollen analysis. At c. 12.400 BP a climatic change from arctic, dry, and continental, to subarctic and more humid and maritime conditions occurred in southern Sweden. The Older Dryas stadial (c.12.200-12.000 BP) is characterized by a temporary return to generally colder , drier, and more continental conditions, followed by generally favourable (subarctic), although unstable, climatic conditions. At c. 11.300 BP a gradual transition towards a colder and more continental climate was initiated, followed by total absence of limnic carbonates during the Younger Dryas stadial (c. 11.000-10.200 BP), indicating arctic and continental conditions. The transition to the Holocene is characterized by a rapid and strong climatic warming. The results from northern Poland point to some important differences compared to this development. A climatic warming around 13.000 BP was followed by generally favourable climatic conditions enabling continuous sedimentation of limnic carbonates during the Late Weichselian. Distinct depletions of 13 C in lacustrine organic material at the transition to the Holocene were recorded in southern Sweden, also demonstrated by decreasing mean values obtained from an extensive compilation of δ 13 C data. A number of processes that may

  5. Carbon sequestration potential of soils in southeast Germany derived from stable soil organic carbon saturation.

    Science.gov (United States)

    Wiesmeier, Martin; Hübner, Rico; Spörlein, Peter; Geuß, Uwe; Hangen, Edzard; Reischl, Arthur; Schilling, Bernd; von Lützow, Margit; Kögel-Knabner, Ingrid

    2014-02-01

    Sequestration of atmospheric carbon (C) in soils through improved management of forest and agricultural land is considered to have high potential for global CO2 mitigation. However, the potential of soils to sequester soil organic carbon (SOC) in a stable form, which is limited by the stabilization of SOC against microbial mineralization, is largely unknown. In this study, we estimated the C sequestration potential of soils in southeast Germany by calculating the potential SOC saturation of silt and clay particles according to Hassink [Plant and Soil 191 (1997) 77] on the basis of 516 soil profiles. The determination of the current SOC content of silt and clay fractions for major soil units and land uses allowed an estimation of the C saturation deficit corresponding to the long-term C sequestration potential. The results showed that cropland soils have a low level of C saturation of around 50% and could store considerable amounts of additional SOC. A relatively high C sequestration potential was also determined for grassland soils. In contrast, forest soils had a low C sequestration potential as they were almost C saturated. A high proportion of sites with a high degree of apparent oversaturation revealed that in acidic, coarse-textured soils the relation to silt and clay is not suitable to estimate the stable C saturation. A strong correlation of the C saturation deficit with temperature and precipitation allowed a spatial estimation of the C sequestration potential for Bavaria. In total, about 395 Mt CO2 -equivalents could theoretically be stored in A horizons of cultivated soils - four times the annual emission of greenhouse gases in Bavaria. Although achieving the entire estimated C storage capacity is unrealistic, improved management of cultivated land could contribute significantly to CO2 mitigation. Moreover, increasing SOC stocks have additional benefits with respect to enhanced soil fertility and agricultural productivity. © 2013 John Wiley & Sons Ltd.

  6. Spectroscopic (multi-energy) CT distinguishes iodine and barium contrast material in MICE.

    Science.gov (United States)

    Anderson, N G; Butler, A P; Scott, N J A; Cook, N J; Butzer, J S; Schleich, N; Firsching, M; Grasset, R; de Ruiter, N; Campbell, M; Butler, P H

    2010-09-01

    Spectral CT differs from dual-energy CT by using a conventional X-ray tube and a photon-counting detector. We wished to produce 3D spectroscopic images of mice that distinguished calcium, iodine and barium. We developed a desktop spectral CT, dubbed MARS, based around the Medipix2 photon-counting energy-discriminating detector. The single conventional X-ray tube operated at constant voltage (75 kVp) and constant current (150 microA). We anaesthetised with ketamine six black mice (C57BL/6). We introduced iodinated contrast material and barium sulphate into the vascular system, alimentary tract and respiratory tract as we euthanised them. The mice were preserved in resin and imaged at four detector energy levels from 12 keV to 42 keV to include the K-edges of iodine (33.0 keV) and barium (37.4 keV). Principal component analysis was applied to reconstructed images to identify components with independent energy response, then displayed in 2D and 3D. Iodinated and barium contrast material was spectrally distinct from soft tissue and bone in all six mice. Calcium, iodine and barium were displayed as separate channels on 3D colour images at contrast agents with K-edges only 4 keV apart. Multi-contrast imaging and molecular CT are potential future applications.

  7. Spectroscopic (multi-energy) CT distinguishes iodine and barium contrast material in MICE

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, N.G. [University of Otago, Department of Radiology, Christchurch (New Zealand); Butler, A.P. [University of Otago, Department of Radiology, Christchurch (New Zealand); University of Canterbury, Physics and Astronomy, Christchurch (New Zealand); Scott, N.J.A. [University of Otago, Department of Medicine, Christchurch (New Zealand); Cook, N.J. [Christchurch Hospital, Medical Physics and Bioengineering, Christchurch (New Zealand); Butzer, J.S. [Karlsruhe Institute of Technology, Physics Department, Karlsruhe (Germany); Schleich, N. [University of Canterbury, Physics and Astronomy, Christchurch (New Zealand); Christchurch Hospital, Medical Physics and Bioengineering, Christchurch (New Zealand); Firsching, M. [Friedrich Alexander University, Physics Department, Erlangen (Germany); Grasset, R.; Ruiter, N. de [University of Canterbury, Hitlab NZ, Christchurch (New Zealand); Campbell, M. [European Organisation for Nuclear Research, Physics Section, Geneva (Switzerland); Butler, P.H. [University of Canterbury, Physics and Astronomy, Christchurch (New Zealand)

    2010-09-15

    Spectral CT differs from dual-energy CT by using a conventional X-ray tube and a photon-counting detector. We wished to produce 3D spectroscopic images of mice that distinguished calcium, iodine and barium. We developed a desktop spectral CT, dubbed MARS, based around the Medipix2 photon-counting energy-discriminating detector. The single conventional X-ray tube operated at constant voltage (75 kVp) and constant current (150 {mu}A). We anaesthetised with ketamine six black mice (C57BL/6). We introduced iodinated contrast material and barium sulphate into the vascular system, alimentary tract and respiratory tract as we euthanised them. The mice were preserved in resin and imaged at four detector energy levels from 12 keV to 42 keV to include the K-edges of iodine (33.0 keV) and barium (37.4 keV). Principal component analysis was applied to reconstructed images to identify components with independent energy response, then displayed in 2D and 3D. Iodinated and barium contrast material was spectrally distinct from soft tissue and bone in all six mice. Calcium, iodine and barium were displayed as separate channels on 3D colour images at <55 {mu}m isotropic voxels. Spectral CT distinguishes contrast agents with K-edges only 4 keV apart. Multi-contrast imaging and molecular CT are potential future applications. (orig.)

  8. A Comparative Study on Magnetostructural Properties of Barium Hexaferrite Powders Prepared by Polyethylene Glycol

    OpenAIRE

    Zehra Durmus

    2014-01-01

    Nanocrystalline particles of barium hexaferrite were synthesized by a sol-gel combustion route using nitrate-citrate gels prepared from metal nitrates and citric acid solutions with Fe/Ba molar ratio 12. The present paper aims to study the effect of addition of polyethylene glycol (PEG) solutions with different molecular weights (MW: 400, 2000, and 10.000 g/mol) on magnetostructural properties of barium hexaferrite. The formation of the barium hexaferrite was inspected using X-ray diffractio...

  9. Sensitivity of single contrast barium enema with regard to colorectal disease as diagnosed by colonoscopy

    International Nuclear Information System (INIS)

    Kaude, J.V.; Harty, R.F.

    1982-01-01

    The results of single contrast barium enema were retrospectively correlated with colonoscopically diagnosed colorectal disease in 54 patients (75 lesions). Altogether 66 lesions (88%) were correctly diagnosed. The sensitivity of barium enema for polyps was 81% (26/32). There were three perceptive errors and three polyps 5 mm or less in size were not demonstrated by barium enema. Twenty-nine cases of inflammatory disorders were all correctly diagnosed. One of 12 malignancies was missed by perceptive error. In two cases with vascular malformations the barium enema was normal. 4/9 (44%) of missed lesions were perceptive errors and could have been probably avoided by a second independent reading of films. (orig.)

  10. Efficacy of Barium-Based Fecal Tagging for CT Colonography: a Comparison between the Use of High and Low Density Barium Suspensions in a Korean Population - a Preliminary Study

    Science.gov (United States)

    Kim, Min Ju; Lee, Seung Soo; Byeon, Jeong-Sik; Choi, Eugene K.; Kim, Jung Hoon; Kim, Yeoung Nam; Kim, Ah Young; Ha, Hyun Kwon

    2009-01-01

    Objective This preliminarily study was designed to determine and to compare the efficacy of two commercially available barium-based fecal tagging agents for CT colonography (CTC) (high-density [40% w/v] and low-density [4.6% w/v] barium suspensions) in a population in Korea. Materials and Methods In a population with an identified with an average-risk for colorectal cancer, 15 adults were administered three doses of 20 ml 40% w/v barium for fecal tagging (group I) and 15 adults were administered three doses of 200 ml 4.6% w/v barium (group II) for fecal tagging. Excluding five patients in group I and one patient in group II that left the study, ten patients in group I and 14 patients in group II were finally included in the analysis. Two experienced readers evaluated the CTC images in consensus regarding the degree of tagging of stool pieces 6 mm or larger. Stool pieces were confirmed with the use of standardized CTC criteria or the absence of matched lesions as seen on colonoscopy. The rates of complete fecal tagging were analyzed on a per-lesion and a per-segment basis and were compared between the patients in the two groups. Results Per-lesion rates of complete fecal tagging were 52% (22 of 42; 95% CI, 37.7-66.6%) in group I and 78% (28 of 36; 95% CI, 61.7-88.5%) in group II. The difference between the two groups did not reach statistical significance (p = 0.285). The per-segment rates of complete tagging were 33% (6 of 18; 95% CI, 16.1%-56.4%) in group I and 60% (9 of 15; 95% CI, 35.7%-80.3%) in group II; again, the difference between the two groups did not reach statistical significance (p = 0.171). Conclusion Barium-based fecal tagging using both the 40% w/v and the 4.6% w/v barium suspensions showed moderate tagging efficacy. The preliminary comparison did not demonstrate a statistically significant difference in the tagging efficacy between the use of the two tagging agents, despite the tendency toward better tagging with the use of the 4.6% w/v barium

  11. Stability of cyclopentadienyl aryloxide complexes of calcium and barium

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, Melanie J.; Burkey, David J.; Chmely, Stephen C. [Department of Chemistry, Vanderbilt University, Nashville, TN 37235 (United States); Hanusa, Timothy P., E-mail: t.hanusa@vanderbilt.ed [Department of Chemistry, Vanderbilt University, Nashville, TN 37235 (United States)

    2009-12-04

    The synthesis of mono(cyclopentadienyl)aryloxide complexes of calcium and barium has been investigated. The reaction of ICa(ODipp)(thf){sub 4} (Odipp = [2,6-iPr-OC{sub 6}H{sub 3}O]{sup -}) with K[C{sub 5}Me{sub 5}], (Cp{sup 3Si}){sub 2}Ca (Cp{sup 3Si} = C{sub 5}(SiMe{sub 3}){sub 3}H{sub 2}) with K[ODipp], and IBa(BHT)(thf){sub 3} (BHT = [2,6-tBu-4-Me-C{sub 6}H{sub 2}O]{sup -}) with K[C{sub 5}Me{sub 5}] in THF produces Cp*Ca(Odipp)(thf){sub 3}, (Cp{sup 3Si})Ca(Odipp)(thf){sub 2}, and Cp*Ba(BHT)(thf), respectively. The crystal structures of the two monomeric calcium complexes are reported. All three compounds are stable against Schlenk rearrangement in THF and aromatic solvents. DFT calculations suggest that the presence of THF has less of an effect on the thermodynamics of Schlenk rearrangements of the aryloxide systems than it does on comparable Cp'CaI compounds.

  12. Comparative evaluation of the fecal-tagging quality in CT colonography: barium vs. iodinated oral contrast agent.

    Science.gov (United States)

    Nagata, Koichi; Singh, Anand Kumar; Sangwaiya, Minal Jagtiani; Näppi, Janne; Zalis, Michael E; Cai, Wenli; Yoshida, Hiroyuki

    2009-11-01

    The purpose of this evaluation was to compare the tagging quality of a barium-based regimen with that of iodine-based regimens for computed tomographic (CT) colonography. Tagging quality was assessed retrospectively in three different types of fecal-tagging CT colonographic cases: 24 barium-based cases, 22 nonionic iodine-based cases, and 24 ionic iodine-based cases. For the purpose of evaluation, the large intestine was divided into six segments, and the tagging homogeneity of a total of 420 segments (70 patients) was graded by three blinded readers from 0 (heterogeneous) to 4 (homogeneous). For barium-based cases, the average score for the three readers was 2.4, whereas it was 3.4 for nonionic iodine and 3.6 for ionic iodine. The percentages of segments that were assigned scores of 4 (excellent tagging [100%]) were 11.6%, 61.9%, and 72.9% for the barium-based, nonionic iodine-based, and ionic iodine-based regimens, respectively. The homogeneity scores of iodine-based fecal-tagging regimens were significantly higher than those of the barium-based fecal-tagging regimen (P barium-based regimen (P barium-based fecal-tagging regimen. Iodine-based fecal-tagging regimens can provide an appropriate method for use in nonlaxative or minimum-laxative CT colonography.

  13. The efficacy of steroids for postoperative persistent inflammatory reaction in a patient with barium peritonitis: A case report

    Directory of Open Access Journals (Sweden)

    Hirofumi Kojima

    2017-01-01

    Conclusion: Residual barium in the intraperitoneal cavity causes persistent inflammatory reaction in patients with barium peritonitis. The use of steroids is effective for postoperative persistent inflammation due to the residual barium.

  14. Structure and multiferroic properties of barium hexaferrite ceramics

    International Nuclear Information System (INIS)

    Tan, Guolong; Chen, Xiuna

    2013-01-01

    Simultaneous occurrence of large ferroelectricity and strong ferromagnetism have been observed in barium hexaferrite ceramics. Barium hexaferrite (BaFe 12 O 19 ) powders with hexagonal crystal structure were successfully synthesized in a polymer precursor method using barium acetate and ferric acetylacetonate as the precursors. The powders were pressed into pellets which were sintered into ceramics at 1200 °C and 1300 °C for 1 h. The structure and morphology of the ceramics were examined using X-ray diffraction and field emission scanning electron microscopy. Large spontaneous polarization was observed in the BaFe 12 O 19 ceramics at room temperature, revealing a clear ferroelectric hysteresis loop. The maximum remanent polarization of the BaFe 12 O 19 ceramic was estimated approximately 11.8 μC cm −2 . The FeO 6 octahedron in its perovskite-like hexagonal unit cell and the shift of Fe 3+ off the center of octahedron are suggested to be the origin of the polarization in BaFe 12 O 19 . The BaFe 12 O 19 ceramics also showed strong ferromagnetism at room temperature. - Graphical abstract: Ferroelectric hysteresis loops of BaFe 12 O 19 ceramics measured at a frequency of 120 Hz, which shows that the ceramics sintered at 1200 °C is ferroelectric with P r ∼11.8 μC/cm 2 . Highlights: ► Large ferroelectricity and strong ferromagnetism were observed in barium hexaferrite ceramics. ► The maximum remanent polarization of the BaFe 12 O 19 ceramic was estimated to be 11.8 μC cm −2 . ► The FeO 6 octahedron and off-center shift of Fe 3+ are suggested to be the origin of the polarization.

  15. PtRu nanoparticles embedded in nitrogen doped carbon with highly stable CO tolerance and durability

    Science.gov (United States)

    Ling, Ying; Yang, Zehui; Yang, Jun; Zhang, Yunfeng; Zhang, Quan; Yu, Xinxin; Cai, Weiwei

    2018-02-01

    As is well known, the lower durability and sluggish methanol oxidation reaction (MOR) of PtRu alloy electrocatalyst blocks the commercialization of direct methanol fuel cells (DMFCs). Here, we design a new PtRu electrocatalyst, with highly stable CO tolerance and durability, in which the PtRu nanoparticles are embedded in nitrogen doped carbon layers derived from carbonization of poly(vinyl pyrrolidone). The newly fabricated electrocatalyst exhibits no loss in electrochemical surface area (ECSA) and MOR activity after potential cycling from 0.6-1.0 V versus reversible hydrogen electrode, while commercial CB/PtRu retains only 50% of its initial ECSA. Meanwhile, due to the same protective layers, the Ru dissolution is decelerated, resulting in stable CO tolerance. Methanol oxidation reaction (MOR) testing indicates that the activity of newly fabricated electrocatalyst is two times higher than that of commercial CB/PtRu, and the fuel cell performance of the embedded PtRu electrocatalyst was comparable to that of commercial CB/PtRu. The embedded PtRu electrocatalyst is applicable in real DMFC operation. This study offers important and useful information for the design and fabrication of durable and CO tolerant electrocatalysts.

  16. The reaction between barium and nitrogen in liquid sodium: resistivity studies

    International Nuclear Information System (INIS)

    Addison, C.C.; Creffield, G.K.; Hubberstey, P.; Pulham, R.J.

    1976-01-01

    The reaction of nitrogen with solutions of barium (between 0.34 and 6.89 mol % Ba) in liquid sodium at 573 K has been followed by changes in the electrical resistivity of the liquid. The capillary method has been employed, continuous sampling during reaction being achieved by electromagnetic pumping. The initial solution of nitrogen in the metal, followed by precipitation of barium and nitrogen from sodium as the nitride Ba 2 N, are reflected in the resistivity changes. The solubility of nitrogen in the alloy is a linear function of the barium concentration: S(mol % N) = x/4 (0 <= x <= 6.89 mol % Ba). This and the decrease in resistivity which invariably occurs during the solution process, provides additional information on the nature of solvation of nitrogen in solution in the liquid metal. (author)

  17. Hot regions of labile and stable soil organic carbon in Germany - Spatial variability and driving factors

    Science.gov (United States)

    Vos, Cora; Jaconi, Angélica; Jacobs, Anna; Don, Axel

    2018-06-01

    Atmospheric carbon dioxide levels can be mitigated by sequestering carbon in the soil. Sequestration can be facilitated by agricultural management, but its influence is not the same on all soil carbon pools, as labile pools with a high turnover may be accumulated much faster but are also more vulnerable to losses. The aims of this study were to (1) assess how soil organic carbon (SOC) is distributed among SOC fractions on a national scale in Germany, (2) identify factors influencing this distribution and (3) identify regions with high vulnerability to SOC losses. The SOC content and proportion of two different SOC fractions were estimated for more than 2500 mineral topsoils (soil texture, bulk soil C / N ratio, total SOC content and pH. For some regions, the drivers were linked to the land-use history of the sites. Arable topsoils in central and southern Germany were found to contain the highest proportions and contents of stable SOC fractions, and therefore have the lowest vulnerability to SOC losses. North-western Germany contains an area of sandy soils with unusually high SOC contents and high proportions of light SOC fractions, which are commonly regarded as representing a labile carbon pool. This is true for the former peat soils in this area, which have already lost and are at high risk of losing high proportions of their SOC stocks. Those black sands can, however, also contain high amounts of stable SOC due to former heathland vegetation and need to be treated and discussed separately from non-black sand agricultural soils. Overall, it was estimated that, in large areas all over Germany, over 30 % of SOC is stored in easily mineralisable forms. Thus, SOC-conserving management of arable soils in these regions is of great importance.

  18. ZnO-carbon nanofibers for stable, high response, and selective H2S sensors.

    Science.gov (United States)

    Zhang, Jitao; Zhu, Zijian; Chen, Changmiao; Chen, Zhi; Cai, Mengqiu; Qu, Baihua; Wang, Taihong; Zhang, Ming

    2018-07-06

    Hydrogen sulfide (H 2 S), as a typical atmospheric pollutant, is neurotoxic and flammable even at a very low concentration. In this study, we design stable H 2 S sensors based on ZnO-carbon nanofibers. Nanofibers with 30.34 wt% carbon are prepared by a facial electrospinning route followed by an annealing treatment. The resulting H 2 S sensors show excellent selectivity and response compared to the pure ZnO nanofiber H 2 S sensors, particularly the response in the range of 102-50 ppm of H 2 S. Besides, they exhibited a nearly constant response of approximately 40-20 ppm of H 2 S over 60 days. The superior performance of these H 2 S sensors can be attributed to the protection of carbon, which ensures the high stability of ZnO, and oxygen vacancies that improve the response and selectivity of H 2 S. The good performance of ZnO-carbon H 2 S sensors suggests that composites with oxygen vacancies prepared by a facial electrospinning route may provide a new research strategy in the field of gas sensors, photocatalysts, and semiconductor devices.

  19. Virtual colonoscopy with electron beam CT: correlation with barium enema, colonoscopy and pathology

    International Nuclear Information System (INIS)

    Hong, Hye Suk; Kim, Min Jung; Chung, Jae Joon; Kim, Myeong Jin; Lee, Jong Tae; Yoo, Hyung Sik

    1998-01-01

    To perform virtual colonoscopy using electron beam tomography(EBT) in patients in whom a colonic mass was present, and to compare the results with those obtained using barium enema, colonoscopy and gross pathologic specimens. Materials and Methods : Ten patients in whom colonic masses were diagnosed by either barium enema or colonoscopy were involved in this study. There were nine cases of adenocarcinoma and one of tubulovillous adenoma. Using EBT preoperative abdominopelvic CT scans were performed. Axial scans were then three-dimensionally reconstructed to produce virtual colonoscopic images and were compared with barium enema, colonoscopy and gross pathologic specimens. Virtual colonoscopic images of the masses were classified as either 1)polyploid, 2)sessile,3)fungating, or 4)annular constrictive. We also determined whether ulcers were present within the lesions and whether there was obstruction. Results : After virtual colonoscopy, two lesions were classified as polyploid, one as sessile, five as fungating and two as annular constrictive. Virtual colonoscopic images showed good correlation with the findings of barium enema, colonoscopy and gross pathologic specimens. Three of six ulcerative lesions were observed on colonoscopy; in seven adenocarcinomas with partial or total luminal obstruction, virtual colonoscopy visualized the colon beyond the obstructed sites. In one case, barium contrast failed to pass through the obstructed portion and in six cases, the colonoscope similarly failed. Conclusion : Virtual colonoscopies correlated well with barium enema, colonoscopy and gross pathologic specimens. They provide three dimensional images of colonic masses and are helpful for the evaluation of obstructive lesions

  20. Intra-individual comparison of patient acceptability of multidetector-row CT colonography and double-contrast barium enema

    International Nuclear Information System (INIS)

    Taylor, S.A.; Halligan, S.; Burling, D.; Bassett, P.; Bartram, C.I.

    2005-01-01

    AIMS: To compare the subjective acceptability of CT colonography in comparison with barium enema in older symptomatic patients, and to ascertain preferences for future colonic investigation. MATERIALS AND METHODS: The study population comprised 78 persons aged 60 years or over with symptoms suggestive of colorectal neoplasia, who underwent CT colonography followed the same day by barium enema. A 25-point questionnaire was administered after each procedure and an additional follow-up questionnaire a week later. Responses were compared using Wilcoxon matched pairs testing, Mann-Whitney test statistics and binomial exact testing. RESULTS: Participants suffered less physical discomfort during CT colonography (p=0.03) and overall satisfaction was greater compared with barium enema (p=0.03). On follow-up, respondents reported significantly better tolerance of CT colonography (p=0.002), and were less prepared to undergo barium enema again (p<0.001). Of 52 subjects expressing an opinion, all preferred CT to barium enema. CONCLUSION: Patient satisfaction was higher with CT colonography than barium enema. CT colonography caused significantly less physical discomfort and was overwhelmingly preferred by patients

  1. Intra-individual comparison of patient acceptability of multidetector-row CT colonography and double-contrast barium enema

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, S.A. [Department of Intestinal Imaging, St Mark' s and Northwick Park Hospitals, London (United Kingdom)]. E-mail: csytaylor@yahoo.co.uk; Halligan, S. [Department of Intestinal Imaging, St Mark' s and Northwick Park Hospitals, London (United Kingdom); Burling, D. [Department of Intestinal Imaging, St Mark' s and Northwick Park Hospitals, London (United Kingdom); Bassett, P. [Department of Intestinal Imaging, St Mark' s and Northwick Park Hospitals, London (United Kingdom); Bartram, C.I. [Department of Intestinal Imaging, St Mark' s and Northwick Park Hospitals, London (United Kingdom)

    2005-02-01

    AIMS: To compare the subjective acceptability of CT colonography in comparison with barium enema in older symptomatic patients, and to ascertain preferences for future colonic investigation. MATERIALS AND METHODS: The study population comprised 78 persons aged 60 years or over with symptoms suggestive of colorectal neoplasia, who underwent CT colonography followed the same day by barium enema. A 25-point questionnaire was administered after each procedure and an additional follow-up questionnaire a week later. Responses were compared using Wilcoxon matched pairs testing, Mann-Whitney test statistics and binomial exact testing. RESULTS: Participants suffered less physical discomfort during CT colonography (p=0.03) and overall satisfaction was greater compared with barium enema (p=0.03). On follow-up, respondents reported significantly better tolerance of CT colonography (p=0.002), and were less prepared to undergo barium enema again (p<0.001). Of 52 subjects expressing an opinion, all preferred CT to barium enema. CONCLUSION: Patient satisfaction was higher with CT colonography than barium enema. CT colonography caused significantly less physical discomfort and was overwhelmingly preferred by patients.

  2. Spectroscopic (multi-energy) CT distinguishes iodine and barium contrast material in MICE

    CERN Document Server

    Anderson, NG; Firsching, M; de Ruiter, N; Schleich, N; Butzer, J S; Cook, N J; Grasset, R; Campbell, M; Scott, N J A; Anderson, N G

    2010-01-01

    Spectral CT differs from dual-energy CT by using a conventional X-ray tube and a photon-counting detector. We wished to produce 3D spectroscopic images of mice that distinguished calcium, iodine and barium. We developed a desktop spectral CT, dubbed MARS, based around the Medipix2 photon-counting energy-discriminating detector. The single conventional X-ray tube operated at constant voltage (75 kVp) and constant current (150 A mu A). We anaesthetised with ketamine six black mice (C57BL/6). We introduced iodinated contrast material and barium sulphate into the vascular system, alimentary tract and respiratory tract as we euthanised them. The mice were preserved in resin and imaged at four detector energy levels from 12 keV to 42 keV to include the K-edges of iodine (33.0 keV) and barium (37.4 keV). Principal component analysis was applied to reconstructed images to identify components with independent energy response, then displayed in 2D and 3D. Iodinated and barium contrast material was spectrally distinct f...

  3. Imaging assessment of the modified double contrast barium enema using carboxymethylcellulose on radiography and ultrasonography in dogs.

    Science.gov (United States)

    Choi, Mihyun; Lee, Namsoon; Kim, Junyoung; Yi, Kangjae; Jung, Joohyun; Yoon, Junghee; Choi, Mincheol

    2011-01-01

    A modified double contrast barium enema using carboxymethylcellulose was evaluated in beagle dogs and compared with dogs receiving a conventional barium enema. The experimental group was divided into three groups (1, 2, and 3) and given 30 ml/kg of different volume ratios of a barium vs. carboxymethylcellulose mixture. Each group underwent sonography following radiography. The volume ratio of one part barium to three parts carboxymethylcellulose was judged to be the optimal mixture, resulting in a general distribution of contrast and bowel radiolucency on radiographs and adequate postradiography sonography. The modified barium enema using carboxymethylcellulose is useful for assessing the general morphology and mucosal layers of the colon simultaneously on radiographs and ultrasonographs.

  4. Self-assembled air-stable magnesium hydride embedded in 3-D activated carbon for reversible hydrogen storage.

    Science.gov (United States)

    Shinde, S S; Kim, Dong-Hyung; Yu, Jin-Young; Lee, Jung-Ho

    2017-06-01

    The rational design of stable, inexpensive catalysts with excellent hydrogen dynamics and sorption characteristics under realistic environments for reversible hydrogen storage remains a great challenge. Here, we present a simple and scalable strategy to fabricate a monodispersed, air-stable, magnesium hydride embedded in three-dimensional activated carbon with periodic synchronization of transition metals (MHCH). The high surface area, homogeneous distribution of MgH 2 nanoparticles, excellent thermal stability, high energy density, steric confinement by carbon, and robust architecture of the catalyst resulted in a noticeable enhancement of the hydrogen storage performance. The resulting MHCH-5 exhibited outstanding hydrogen storage performance, better than that of most reported Mg-based hydrides, with a high storage density of 6.63 wt% H 2 , a rapid kinetics loading in hydrogenation compared to that of commercial MgH 2 . The origin of the intrinsic hydrogen thermodynamics was elucidated via solid state 1 H NMR. This work presents a readily scaled-up strategy towards the design of realistic catalysts with superior functionality and stability for applications in reversible hydrogen storage, lithium ion batteries, and fuel cells.

  5. Application of carbon and hydrogen stable isotope analyses to detect exogenous citric acid in Japanese apricot liqueur.

    Science.gov (United States)

    Akamatsu, Fumikazu; Oe, Takaaki; Hashiguchi, Tomokazu; Hisatsune, Yuri; Kawao, Takafumi; Fujii, Tsutomu

    2017-08-01

    Japanese apricot liqueur manufacturers are required to control the quality and authenticity of their liqueur products. Citric acid made from corn is the main acidulant used in commercial liqueurs. In this study, we conducted spiking experiments and carbon and hydrogen stable isotope analyses to detect exogenous citric acid used as an acidulant in Japanese apricot liqueurs. Our results showed that the δ 13 C values detected exogenous citric acid originating from C 4 plants but not from C 3 plants. The δ 2 H values of citric acid decreased as the amount of citric acid added increased, whether the citric acid originated from C 3 or C 4 plants. Commercial liqueurs with declared added acidulant provided higher δ 13 C values and lower δ 2 H values than did authentic liqueurs and commercial liqueurs with no declared added acidulant. Carbon and hydrogen stable isotope analyses are suitable as routine methods for detecting exogenous citric acid in Japanese apricot liqueur. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Acute respiratory failure caused by aspiration of high density barium: A case report

    International Nuclear Information System (INIS)

    Park, Ki Soon; Jung, Eun A; Yang, Ik; Lee, Yul; Chung, Soo Young

    1994-01-01

    Accidental aspiration of barium contrast medium during the upper gastrointestinal study can occur in patients with swallowing disorder, especially in the elderly patients. We experienced a case of respiratory failure followed by death within a few hours in 85 year-old patient after barium aspiration

  7. Imaging diagnosis--duodenobiliary reflux of barium sulfate during esophagogastrography in a dog.

    Science.gov (United States)

    Shaikh, Layla; Sharma, Ajay; Secrest, Scott

    2015-01-01

    A 4-year-old Australian cattle dog presented for regurgitation, 2 months after duodenal resection and anastomosis for a perforated duodenal ulcer. Duodenobiliary reflux of barium sulfate suspension was detected during fluoroscopic esophagogastrography. Follow-up radiography 2 hours later demonstrated persistence of the barium in the gallbladder and biliary tree. Ultrasonography showed an open sphincter of Oddi but no other morphological abnormalities with the gallbladder or biliary system. No side effects or bloodwork abnormalities were noted. This is the first case report of duodenobiliary reflux of barium in a dog. The pathophysiology of this phenomenon and its incidence and significance in human medicine are discussed. © 2014 American College of Veterinary Radiology.

  8. Prospective comparison of air-contrast barium enema and colonoscopy in patients with fecal occult blood: a pilot study.

    Science.gov (United States)

    Rockey, Don C; Koch, Johannes; Yee, Judy; McQuaid, Kenneth R; Halvorsen, Robert A

    2004-12-01

    The utility of air-contrast barium enema and colonoscopy for evaluation of the colon has been debated. Air-contrast barium enema is less expensive and invasive than colonoscopy, but it also is less sensitive and specific. Further, although air-contrast barium enema may be less painful than colonoscopy, it often is poorly tolerated by patients. Thus, this study compared the sensitivity and the specificity of air-contrast barium enema and colonoscopy for detection of colonic lesions in patients with fecal occult blood. Over a 30-month period, patients with fecal occult blood were recruited. Patients underwent standard air-contrast barium enema, followed by colonoscopy 7 to 14 days later. Colonoscopists were blinded to the results of air-contrast barium enema until the colonoscopy was completed, after which the results were disclosed. If the findings were discrepant, colonoscopy was repeated. A total of 100 patients were evaluated. Nine air-contrast barium enemas were reported to be inadequate, and the cecum was not intubated at colonoscopy in two patients. In the remaining patients, 5 cancers were identified (1 each cecum, transverse colon, descending colon, sigmoid colon, and rectum) by both studies. Sixty-six polypoid lesions were identified in 30 patients. Diverticula were identified in 42 patients by air-contrast barium enema and in 18 patients by colonoscopy. Air-contrast barium enema detected 3 of 36 polypoid lesions 5 mm or less in diameter, 5 of 15 adenomas 6 to 9 mm in size, and 4 of 15 adenomas 10 mm or greater in diameter (sensitivity 8%, 33%, and 27%, respectively). After excluding patients with diverticula, air-contrast barium enema detected 3 of 7 adenomas 10 mm or greater in size. Overall, 12 polypoid lesions or filling defects were identified by air-contrast barium enema that could not be verified by colonoscopy. The specificity of air-contrast barium enema for lesions 1.0 cm or greater in size was 100%; for those 6 mm or greater, it was 97%. Air

  9. The Kerr nonlinearity of the beta-barium borate crystal

    DEFF Research Database (Denmark)

    Bache, Morten; Guo, Hairun; Zhou, Binbin

    2013-01-01

    A popular crystal for ultrafast cascading experiments is beta-barium-borate (β-BaB2O4, BBO). It has a decent quadratic nonlinear coefficient, and because the crystal is anisotropie it can be birefringence phase-matched for type I (oo → e) second-harmonic generation (SHG). For femtosecond experime......A popular crystal for ultrafast cascading experiments is beta-barium-borate (β-BaB2O4, BBO). It has a decent quadratic nonlinear coefficient, and because the crystal is anisotropie it can be birefringence phase-matched for type I (oo → e) second-harmonic generation (SHG). For femtosecond...

  10. Comparison of barium swallow and ultrasound in diagnosis of gastro-oesophageal reflux in children.

    Science.gov (United States)

    Naik, D R; Bolia, A; Moore, D J

    1985-01-01

    Fifty one infants and older children with suspected gastro-oesophageal reflux entered a study comparing the diagnostic accuracy of a standard barium swallow examination with that of ultrasound scanning. All children were examined by both techniques. In 40 cases there was unequivocal agreement between the examinations. Of the remaining patients, four had definite reflux by ultrasonic criteria but showed no evidence of reflux on barium swallow examination, four had positive findings on ultrasound but showed only minimal reflux on barium swallow, and one showed minimal reflux on ultrasound but had a negative barium meal result. In two children the ultrasound study was inconclusive. Ultrasound has an important role in the diagnosis and follow up of patients under the age of 5 years with gastro-oesophageal reflux. Images FIG 1 FIG 2 PMID:3924317

  11. Optimizing sample pretreatment for compound-specific stable carbon isotopic analysis of amino sugars in marine sediment

    Science.gov (United States)

    Zhu, R.; Lin, Y.-S.; Lipp, J. S.; Meador, T. B.; Hinrichs, K.-U.

    2014-09-01

    Amino sugars are quantitatively significant constituents of soil and marine sediment, but their sources and turnover in environmental samples remain poorly understood. The stable carbon isotopic composition of amino sugars can provide information on the lifestyles of their source organisms and can be monitored during incubations with labeled substrates to estimate the turnover rates of microbial populations. However, until now, such investigation has been carried out only with soil samples, partly because of the much lower abundance of amino sugars in marine environments. We therefore optimized a procedure for compound-specific isotopic analysis of amino sugars in marine sediment, employing gas chromatography-isotope ratio mass spectrometry. The whole procedure consisted of hydrolysis, neutralization, enrichment, and derivatization of amino sugars. Except for the derivatization step, the protocol introduced negligible isotopic fractionation, and the minimum requirement of amino sugar for isotopic analysis was 20 ng, i.e., equivalent to ~8 ng of amino sugar carbon. Compound-specific stable carbon isotopic analysis of amino sugars obtained from marine sediment extracts indicated that glucosamine and galactosamine were mainly derived from organic detritus, whereas muramic acid showed isotopic imprints from indigenous bacterial activities. The δ13C analysis of amino sugars provides a valuable addition to the biomarker-based characterization of microbial metabolism in the deep marine biosphere, which so far has been lipid oriented and biased towards the detection of archaeal signals.

  12. Recovery and separation of rare-earth elements, barium, and strontium from bastnasite with sulfuric acid

    International Nuclear Information System (INIS)

    Eisele, J.A.; Bauer, D.J.

    1974-01-01

    A bench-scale investigation was made of a concentrated H 2 SO 4 reaction for recovering and separating rare earth elements, barium, and strontium from a bastnaesite ore and byproduct. Barium and strontium were dissolved in the concentrated acid and precipitated as a mixed product by water dilution. Separation of strontium from barium was effected by reaction with Na 2 CO 3 solution, followed by a dilute acid leach of the SrCO 3 formed. After removing the barium and strontium from bastnaesite ore, the rare-earth elements were roasted to water-soluble sulfates. The rare earth sulfate solution was subsequently processed by solvent extraction to produce rare-earth oxides low in lead and magnesium. (U.S.)

  13. Dynamics of Carbonates in Soils under Different Land Use in Forest-Steppe Area of Russia Using Stable and Radiogenic Carbon Isotope Data

    Directory of Open Access Journals (Sweden)

    Olga Khokhlova

    2018-04-01

    Full Text Available The work is aimed at the analysis of carbonate dynamics in soils under different land use. The studied area is located in the forest steppe - of the Central Russian Upland. Soils were sampled at four sites: a broadleaf forest, an adjacent 50-year continuously cropped field including plots under a corn monoculture, bare fallow, and a crop rotation area with a clean fallow every fourth year. The carbonates’ morphology, their chemical composition, as well as their stable and radiogenic isotopes of carbon were studied. Clear-cut distinctions were found in the carbonate distribution throughout the profiles in the microstructure of carbonate pedofeatures, carbon isotopic composition, and radiocarbon age of carbonates between the pairs of the plots as follows: the bare fallow and the crop rotation on the one hand, and the corn monoculture and forest on the other. The distinctions are commonly assumed to result from repeating upward water fluxes, which are different in the bare soils and those with plant cover. A clear difference occurred in the hydrothermal regime for soils with and without plant cover, and was found to be the key factor of the observed differences. In addition, in soils under plant cover, the carbonate migration upward occurs due to process of transpiration, whereas in soils devoid of plants, it occurs due to physical evaporation.

  14. Radiocarbon and stable-isotope geochemistry of organic and inorganic carbon in Lake Superior

    Science.gov (United States)

    Zigah, Prosper K.; Minor, Elizabeth C.; Werne, Josef P.

    2012-03-01

    We present a lake-wide investigation of Lake Superior carbon and organic matter biogeochemistry using radiocarbon, stable isotope, and carbon concentrations. Dissolved inorganic carbon (DIC) abundance in the lake was 121-122 Tg C, with offshore concentration andδ13C values being laterally homogenous and tightly coupled to the physical and thermal regime and biochemical processes. Offshore Δ14C of DIC (50-65‰) exhibited lateral homogeneity and was more 14C enriched than co-occurring atmospheric CO2 (˜38‰); nearshore Δ14C of DIC (36-38‰) was similar to atmospheric CO2. Dissolved organic carbon (DOC) abundance was 14.2-16.4 Tg C. DOC's concentration and δ13C were homogenous in June (mixed lake), but varied laterally during August (stratification) possibly due to spatial differences in lake productivity. Throughout sampling, DOC had modern radiocarbon values (14-58‰) indicating a semilabile nature with a turnover time of ≤60 years. Lake particulate organic carbon (POC, 0.9-1.3 Tg C) was consistently 13C depleted relative to DOC. The δ15N of epilimnetic particulate organic nitrogen shifted to more negative values during stratification possibly indicating greater use of nitrate (rather than ammonium) by phytoplankton in August. POC's radiocarbon was spatially heterogeneous (Δ14C range: 58‰ to -303‰), and generally 14C depleted relative to DOC and DIC. POC 14C depletion could not be accounted for by black carbon in the lake but, because of its spatial and temporal distribution, is attributed to sediment resuspension. The presence of old POC within the epilimnion of the open lake indicates possible benthic-pelagic coupling in the lake's organic carbon cycle; the ultimate fate of this old POC bears further investigation.

  15. Comparison of Calcium and Barium Microcapsules as Scaffolds in the Development of Artificial Dermal Papillae.

    Science.gov (United States)

    Liu, Yang; Lin, Changmin; Zeng, Yang; Li, Haihong; Cai, Bozhi; Huang, Keng; Yuan, Yanping; Li, Yu

    2016-01-01

    This study aimed to develop and evaluate barium and calcium microcapsules as candidates for scaffolding in artificial dermal papilla. Dermal papilla cells (DPCs) were isolated and cultured by one-step collagenase treatment. The DPC-Ba and DPC-Ca microcapsules were prepared by using a specially designed, high-voltage, electric-field droplet generator. Selected microcapsules were assessed for long-term inductive properties with xenotransplantation into Sprague-Dawley rat ears. Both barium and calcium microcapsules maintained xenogenic dermal papilla cells in an immunoisolated environment and induced the formation of hair follicle structures. Calcium microcapsules showed better biocompatibility, permeability, and cell viability in comparison with barium microcapsules. Before 18 weeks, calcium microcapsules gathered together, with no substantial immune response. After 32 weeks, some microcapsules were near inflammatory cells and wrapped with fiber. A few large hair follicles were found. Control samples showed no marked changes at the implantation site. Barium microcapsules were superior to calcium microcapsules in structural and mechanical stability. The cells encapsulated in hydrogel barium microcapsules exhibited higher short-term viability. This study established a model to culture DPCs in 3D culture conditions. Barium microcapsules may be useful in short-term transplantation study. Calcium microcapsules may provide an effective scaffold for the development of artificial dermal papilla.

  16. Effect of barium-coated halloysite nanotube addition on the cytocompatibility, mechanical and contrast properties of poly(methyl methacrylate) cement.

    Science.gov (United States)

    Jammalamadaka, Uday; Tappa, Karthik; Weisman, Jeffery A; Nicholson, James Connor; Mills, David K

    2017-01-01

    Halloysite nanotubes (HNTs) were investigated as a platform for tunable nanoparticle composition and enhanced opacity in poly(methyl methacrylate) (PMMA) bone cement. Halloysite has been widely used to increase the mechanical properties of various polymer matrices, in stark contrast to other fillers such as barium sulfate that provide opacity but also decrease mechanical strength. The present work describes a dry deposition method for successively fabricating barium sulfate nanoparticles onto the exterior surface of HNTs. A sintering process was used to coat the HNTs in barium sulfate. Barium sulfate-coated HNTs were then added to PMMA bone cement and the samples were tested for mechanical strength and tailored opacity correlated with the fabrication ratio and the amount of barium sulfate-coated HNTs added. The potential cytotoxic effect of barium-coated HNTs in PMMA cement was also tested on osteosarcoma cells. Barium-coated HNTs were found to be completely cytocompatible, and cell proliferation was not inhibited after exposure to the barium-coated HNTs embedded in PMMA cement. We demonstrate a simple method for the creation of barium-coated nanoparticles that imparted improved contrast and material properties to native PMMA. An easy and efficient method for coating clay nanotubes offers the potential for enhanced imaging by radiologists or orthopedic surgeons.

  17. The origin of barium in the Cambrian–Vendian aquifer system, North Estonia

    Directory of Open Access Journals (Sweden)

    Mokrik, Robert

    2009-09-01

    Full Text Available Identification of the barium occurrence and its origin is made on the basis of the groundwater chemistry study. High Ba content has been detected in the Cambrian–Vendian aquifer system in the coastal vicinity of the Gulf of Finland in Estonia and St Petersburg. The dissolution of Ba from witherite as the primary source was derived from the analysis of the aqueous solution equilibrium with Ba-related minerals. It is reflected in the chemical composition of groundwater and influenced by the galenite–calcite–fluorite polymetallic mineralization in Vendian sandstones. The dissolution and re-deposition of carbonates and baryte are confirmed by mineral saturation states for an aqueous solution and distribution of other species in the groundwater of the Cambrian–Vendian aquifer system in North Estonia.

  18. Development of a Method to Isolate Glutamic Acid from Foodstuffs for a Precise Determination of Their Stable Carbon Isotope Ratio.

    Science.gov (United States)

    Kobayashi, Kazuhiro; Tanaka, Masaharu; Yatsukawa, Yoichi; Tanabe, Soichi; Tanaka, Mitsuru; Ohkouchi, Naohiko

    2018-01-01

    Recent growing health awareness is leading to increasingly conscious decisions by consumers regarding the production and traceability of food. Stable isotopic compositions provide useful information for tracing the origin of foodstuffs and processes of food production. Plants exhibit different ratios of stable carbon isotopes (δ 13 C) because they utilized different photosynthetic (carbon fixation) pathways and grow in various environments. The origins of glutamic acid in foodstuffs can be differentiated on the basis of these photosynthetic characteristics. Here, we have developed a method to isolate glutamic acid in foodstuffs for determining the δ 13 C value by elemental analyzer-isotope-ratio mass spectrometry (EA/IRMS) without unintended isotopic fractionation. Briefly, following acid-hydrolysis, samples were defatted and passed through activated carbon and a cation-exchange column. Then, glutamic acid was isolated using preparative HPLC. This method is applicable to measuring, with a low standard deviation, the δ 13 C values of glutamic acid from foodstuffs derived from C3 and C4 plants and marine algae.

  19. [Value of preoperative barium contrast examination for the diagnosis and operative planning in gastric cancer].

    Science.gov (United States)

    Wang, Chang-jian; Zhao, Guang-fa; Li, Qing-guo; Chen, Jing-gui; Zhu, Kai; Shi, Ying-qiang; Fu, Hong

    2010-04-01

    To investigate the value of preoperative barium contrast examination for the diagnosis and operative planning in gastric cancer. Clinical data of 229 gastric cancer patients were analyzed retrospectively. Lesions were divided into three parts: the cardiac, the body, and the antrum. The diagnostic accuracy of localization and the extent of tumor between gastroscopy alone and gastroscopy plus barium contrast were compared with the results of surgical findings. The diagnostic accuracy of localization and the extent of tumor for gastroscopy in the cardiac, the body and the antrum cancers were 100% and 78.4%, 94.6% and 86.5%, 98.1% and 84.6%, respectively, while for gastroscopy plus barium contrast were 100% and 84.8%, 100% and 91.9%, 99.0% and 90.4%, respectively. The diagnostic accuracy of both the localization and the extent of tumor were not significantly different between gastroscopy alone and gastroscopy plus barium contrast (P>0.05). Diagnostic accuracy of the length of esophagus infiltrated by cardiac cancer in gastroscopy was 60.6%, while in gastroscopy plus barium contrast was 90.9%, which was significantly different (Pbarium contrast was more accurate in predicting the possibility of thoracotomy in cardiac cancer infiltrating the lower esophagus. It is necessary to perform preoperative barium contrast examination in cardiac cancer patients, so as to identify whether the lower esophagus is infiltrated and to measure the length of lesion, which can provide evidences for making a decision of thoracotomy. For gastric body and antrum cancer, there is no indication for barium contrast examination if gastroscopy findings are satisfied.

  20. Fluoroscopy-guided barium marking for localizing small pulmonary lesions before video-assisted thoracoscopic surgery

    International Nuclear Information System (INIS)

    Yamada, Takahiro; Koyama, Yasunori; Masui, Asami

    2009-01-01

    Small pulmonary lesions not previously seen on chest radiographs will likely be detected with increasing frequency because of the spread of CT screening. For the diagnosis and treatment of such lesions, we frequently perform resection by video-assisted thoracoscopic surgery (VATS). We performed fluoroscopy-guided barium marking for localization of small peripheral pulmonary lesions before VATS resection, and examined its reliability, safety, and usefulness. We studied 46 patients with peripheral pulmonary lesions 20 mm or less in diameter who were scheduled to undergo VATS resection. The average diameter of the lesions was 10.2±0.5 mm (mean±standard error), and the average distance from the pleural surface was 10.1±0.8 mm. The optimal site for the catheter tip was decided on chest radiographs using CT scans for reference beforehand, and a catheter was inserted bronchoscopically into the target segment and guided to the presumed lesion. A 50% (weight/volume) barium sulfate suspension was instilled into the bronchus through the catheter, and the site of barium marking was checked by CT scanning. The average instilled volume of barium was 0.36±0.03 ml. On CT scans, barium spots were superimposed on the target lesions in 35 of the 46 patients and were only 15 mm from the lesions in the other patients. Barium was well recognized in all patients at the time of VATS resection, and we could confirm the diagnosis in all patients. A mild cough persisted for about 1 week in 1 patient, but the other patients had no specific complications. Fluoroscopy-guided barium marking is a safe, convenient, and reliable method for localization of small pulmonary lesions before VATS resection. (author)

  1. Investigation of the microbial metabolism of carbon dioxide and hydrogen in the kangaroo foregut by stable isotope probing.

    Science.gov (United States)

    Godwin, Scott; Kang, Alicia; Gulino, Lisa-Maree; Manefield, Mike; Gutierrez-Zamora, Maria-Luisa; Kienzle, Marco; Ouwerkerk, Diane; Dawson, Kerri; Klieve, Athol V

    2014-09-01

    Kangaroos ferment forage material in an enlarged forestomach analogous to the rumen, but in contrast to ruminants, they produce little or no methane. The objective of this study was to identify the dominant organisms and pathways involved in hydrogenotrophy in the kangaroo forestomach, with the broader aim of understanding how these processes are able to predominate over methanogenesis. Stable isotope analysis of fermentation end products and RNA stable isotope probing (RNA-SIP) were used to investigate the organisms and biochemical pathways involved in the metabolism of hydrogen and carbon dioxide in the kangaroo forestomach. Our results clearly demonstrate that the activity of bacterial reductive acetogens is a key factor in the reduced methane output of kangaroos. In in vitro fermentations, the microbial community of the kangaroo foregut produced very little methane, but produced a significantly greater proportion of acetate derived from carbon dioxide than the microbial community of the bovine rumen. A bacterial operational taxonomic unit closely related to the known reductive acetogen Blautia coccoides was found to be associated with carbon dioxide and hydrogen metabolism in the kangaroo foregut. Other bacterial taxa including members of the genera Prevotella, Oscillibacter and Streptococcus that have not previously been reported as containing hydrogenotrophic organisms were also significantly associated with metabolism of hydrogen and carbon dioxide in the kangaroo forestomach.

  2. Determination of the origin of dissolved inorganic carbon in groundwater around a reclaimed landfill in Otwock using stable carbon isotopes.

    Science.gov (United States)

    Porowska, Dorota

    2015-05-01

    Chemical and isotopic analyses of groundwater from piezometers located around a reclaimed landfill in Otwock (Poland) were performed in order to trace the origin of dissolved inorganic carbon (DIC) in the groundwater. Due to differences in the isotopic composition of carbon from different sources, an analysis of stable carbon isotopes in the groundwater, together with the Keeling plot approach and a two-component mixing model allow us to evaluate the relative contributions of carbon from these sources in the groundwater. In the natural (background) groundwater, DIC concentrations and the isotopic composition of DIC (δ(13)CDIC) comes from two sources: decomposition of organic matter and carbonate dissolution within the aquifer sediments, whereas in the leachate-contaminated groundwater, DIC concentrations and δ(13)CDIC values depend on the degradation of organic matter within the aquifer sediments and biodegradation of organic matter stored in the landfill. From the mixing model, about 4-54% of the DIC pool is derived from organic matter degradation and 96-46% from carbonate dissolution in natural conditions. In the leachate-contaminated groundwater, about 20-53% of the DIC is derived from organic matter degradation of natural origin and 80-47% from biodegradation of organic matter stored in the landfill. Partial pressure of CO2 (P CO2) was generally above the atmospheric, hence atmospheric CO2 as a source of carbon in DIC pool was negligible in the aquifer. P CO2 values in the aquifer in Otwock were always one to two orders of magnitude above the atmospheric P CO2, and thus CO2 escaped directly into the vadose zone. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Benefits of Barium Enema in Patients with Incomplete Colonoscopy. Prospective Study of 45 Cases

    International Nuclear Information System (INIS)

    Gispert, S.; Mayolas, N.; Hidalgo, A.

    2003-01-01

    To evaluate the usefulness of barium enema in patients with incomplete colonoscopy. There was carried out a prospective 10-month study of 45 patients with incomplete colonoscopy (27 men and 18 women), who were later examined by means of barium enema (33 conventional, 12 double-contrast) in order to check for additional pathology in portions of the colon not visualized by colonoscopy. Barium enema diagnosed six possible additional lesions (13.3%) in portions of the colon not visualized by incomplete colonoscopy (four neoplasia and two non-neoplasia). Regarding the neoplasia two were true positives and two false positives. Both true positives were adenocarcinomas (one synchronous caecum, and another in splenic angle). The two false positives corresponded to fecal matter stuck to the intestinal wall. Regarding the non-neoplasia, multiple stenosis was detected in a patient with Crohn's disease and an enterocolic fistula was found in a patient with sigmoid colon neoplasia. The diagnostic yield of barium enema in the detection of additional pathology in colon portions not visualized by colonoscopy was of 9%. Barium enema following incomplete colonoscopy permits a complete colon evaluation in most cases, and it offers additional diagnostic information. (Author) 21 refs

  4. Manufacture of barium hexaferrite (BaO3.98Fe2O3) from iron oxide waste of grinding process by using calcination process

    Science.gov (United States)

    Idayanti, N.; Dedi; Kristiantoro, T.; Mulyadi, D.; Sudrajat, N.; Alam, G. F. N.

    2018-03-01

    The utilization of iron oxide waste of grinding process as raw materials for making barium hexaferrite has been completed by powder metallurgy method. The iron oxide waste was purified by roasting at 800 °C temperature for 3 hours. The method used varying calcination temperature at 1000, 1100, 1200, and 1250 °C for 3 hours. The starting iron oxide waste (Fe2O3) and barium carbonate (BaCO3) were prepared by mol ratio of Fe2O3:BaCO3 from the formula BaO3.98Fe2O3. Some additives such as calcium oxide (CaO), silicon dioxide (SiO2), and polyvinyl alcohol (PVA) were added after calcination process. The samples were formed at the pressure of 2 ton/cm2 and sintered at the temperature of 1250 °C for 1 hour. The formation of barium hexaferrite compounds after calcination is determined by X-Ray diffraction. The magnetic properties were observed by Permagraph-Magnet Physik with the optimum characteristic at calcination temperature of 1250 °C with the induction of remanence (Br) = 1.38 kG, coercivity (HcJ) = 4.533 kOe, product energy maximum (BHmax) = 1.086 MGOe, and density = 4.33 g/cm3.

  5. Colonic transit time in patient with slow-transit constipation: Comparison of radiopaque markers and barium suspension method

    Energy Technology Data Exchange (ETDEWEB)

    Xu Huimin [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China); Department of General Surgery, Weifang People' s Hospital, ShanDong Province 261041 (China); Han Jiagang [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China); Na Ying [Department of Medical Imaging, Weifang People' s Hospital, ShanDong Province 261041 (China); Zhao Bo; Ma Huachong [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China); Wang Zhenjun, E-mail: wang3zj@sohu.com [Department of General Surgery, Beijing Chaoyang Hospital, Capital Medical University, No. 8 Gongtina Lu, Chaoyang District, Beijing 100020 (China)

    2011-08-15

    Background: Colonic transit study provides valuable information before surgical treatment is considered for patient with constipation. The radiopaque markers method is the most common way for evaluating colon transit time. The aim of this study is to compare the barium suspension with the radiopaque makers to assess the colonic mobility in patient with constipation. Methods: Colonic transit time was measured in 11 female patients with slow-transit constipation using both radiopaque markers and barium suspension method. In radiopaque markers method, the patient ingested 20 markers on the first day, and an abdominal radiograph was performed every 24 h until 80% markers were excreted. In barium suspension method, the patient swallowed up to 50 ml of 200% (w/v) barium meal. The abdominal radiographs were taken at the same time point as the former. Results: The total or segmental colonic transit time were obviously prolonged in all patients. Segmental transits time spent in the right colon, left colon and rectosigmoid for radiopaque markers and barium suspension method was, respectively, 30 {+-} 6 h and 34 {+-} 7 h; 38 {+-} 9 h and 32 {+-} 6 h; 40 {+-} 8 h and 38 {+-} 10 h. In the radiopaque markers method, total colonic transit time was 108 {+-} 14 h and it was 103 {+-} 13 h in the barium suspension method (P > 0.05). Conclusion: The barium suspension and radiopaque markers gave the similar results for colonic transit time. The barium suspension was a simple and cheap method for evaluating the colonic mobility.

  6. Electromagnetic properties of photodefinable barium ferrite polymer composites

    Science.gov (United States)

    Sholiyi, Olusegun; Lee, Jaejin; Williams, John D.

    2014-07-01

    This article reports the magnetic and microwave properties of a Barium ferrite powder suspended in a polymer matrix. The sizes for Barium hexaferrite powder are 3-6 μm for coarse and 0.8-1.0 μm for the fine powder. Ratios 1:1 and 3:1 (by mass) of ferrite to SU8 samples were characterized and analyzed for predicting the necessary combinations of these powders with SU8 2000 Negative photoresist. The magnetization properties of these materials were equally determined and were analyzed using Vibrating Sample Magnetometer (VSM). The Thru, Reflect, Line (TRL) calibration technique was employed in determining complex relative permittivity and permeability of the powders and composites with SU8 between 26.5 and 40 GHz.

  7. Electromagnetic properties of photodefinable barium ferrite polymer composites

    Directory of Open Access Journals (Sweden)

    Olusegun Sholiyi

    2014-07-01

    Full Text Available This article reports the magnetic and microwave properties of a Barium ferrite powder suspended in a polymer matrix. The sizes for Barium hexaferrite powder are 3–6 μm for coarse and 0.8–1.0 μm for the fine powder. Ratios 1:1 and 3:1 (by mass of ferrite to SU8 samples were characterized and analyzed for predicting the necessary combinations of these powders with SU8 2000 Negative photoresist. The magnetization properties of these materials were equally determined and were analyzed using Vibrating Sample Magnetometer (VSM. The Thru, Reflect, Line (TRL calibration technique was employed in determining complex relative permittivity and permeability of the powders and composites with SU8 between 26.5 and 40 GHz.

  8. NASA/Max Planck Institute Barium Ion Cloud Project.

    Science.gov (United States)

    Brence, W. A.; Carr, R. E.; Gerlach, J. C.; Neuss, H.

    1973-01-01

    NASA and the Max Planck Institute for Extraterrestrial Physics (MPE), Munich, Germany, conducted a cooperative experiment involving the release and study of a barium cloud at 31,500 km altitude near the equatorial plane. The release was made near local magnetic midnight on Sept. 21, 1971. The MPE-built spacecraft contained a canister of 16 kg of Ba CuO mixture, a two-axis magnetometer, and other payload instrumentation. The objectives of the experiment were to investigate the interaction of the ionized barium cloud with the ambient medium and to deduce the properties of electric fields in the proximity of the release. An overview of the project is given to briefly summarize the organization, responsibilities, objectives, instrumentation, and operational aspects of the project.

  9. The impact of high-density barium use in double contrast radiographic methods for gastric cancer screening in Niigata, Japan.

    Science.gov (United States)

    Wakai, Shizuko; Tanabe, Naohito; Suzuki, Hiroshi

    2005-04-01

    Use of high-density barium (= or > 180 w/v%) has been widely spread in community-based mass screening for gastric cancer in Japan. However, the impact on outcomes of the screening has not been fully evaluated. Then, we investigated the advantage of high-density barium use by comparing the outcomes between a period with high-density barium and that with low-density barium (barium decreases the positive finding rate in initial mass screening x-ray examinations by 12% (odds ratio, 0.88; 95% confidence interval, 0.86 - 0.90) and increase the gastric cancer detection rate by diagnostic examination by 15% (odds ratio, 1.15; 95% confidence interval, 1.01-1.31). We conclude that introduction of high-density barium has improved the efficiency of mass screening for gastric cancer by decreasing unnecessary diagnostic examinations and reducing the total personal and public health costs. Thus, nationwide use of high-density barium is recommended for mass gastric cancer screening in Japan.

  10. Comparison of endoscopy and barium swallow with marshmallow in dysphagia.

    Science.gov (United States)

    Somers, S; Stevenson, G W; Thompson, G

    1986-06-01

    Forty-four patients with dysphagia were examined both by endoscopy and by barium swallow with a marshmallow bolus. In these patients 36 stenoses were found: 34 by radiology and 30 by endoscopy. The radiologic criteria for stenosis included arrest of the marshmallow in a manner to support a column of barium and reproduction of the patient's symptoms at the time this occurred. Radiologic false negative findings were partly due to an inability by patients to swallow an adequate marshmallow bolus; endoscopic failures were associated with small endoscopes and mild stenoses.

  11. Barium Tagging from nEXO Using Resonance Ionization Spectroscopy

    Science.gov (United States)

    Twelker, K.; Kravitz, S.

    nEXO is a 5-ton liquid enriched-xenon time projection chamber (TPC) to search for neutrinoless double-beta decay, designed to have the sensitivity to completely probe the inverted mass hierarchy of Majorana neutrinos. The detector will accommodate-as a background reduction technique-a system to recover and identify the barium decay product. This upgrade will allow a background-free measurement of neutrinoless double-beta decay and increase the half-life sensitivity of the experiment by at least one order of magnitude. Ongoing research and development includes a system to test barium extraction from liquid xenon using surface adsorption and Resonance Ionization Spectroscopy (RIS).

  12. Determination of barium in surface and ground waters at Centro Experimental Aramar area

    Energy Technology Data Exchange (ETDEWEB)

    Matoso, Erika, E-mail: ematoso@hotmail.com [Centro Tecnologico da Marinha em Sao Paulo (CEA/CTMS), Ipero, SP (Brazil). Centro Experimental Aramar; Cadore, Solange, E-mail: cadore@iqm.unicamp.br [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Quimica. Departamento de Quimica Analica

    2015-07-01

    Barium can be found in waters up to 1 mg L{sup -1} and came from natural sources such as sedimentary rocks erosion rich in feldspar and barite. Also anthropogenic activities can release this element such as oil and gas industry, agricultural defensives, chemical industry and waste disposal. At high doses, barium can be harmful to human central nervous system and can also cause high blood pressure, heart problems, fatigue and anxiety. The water potability defined by Brazilian's Ministry of Healthy sets barium concentration up to 0.7 mg L{sup -1} and official regulation defines the same limit of this element to superficial waters (according CONAMA resolution 357/2005) and ground waters (Sao Paulo state regulation). In this work, barium was analyzed monthly in superficial waters from 4 different sampling locations, located in a ratio of 10-km-long from Centro Experimental Aramar (CEA) at Ipanema River, during one year, in order to evaluate the river in different conditions (seasons, temperature and rain period). The ground water was collected every six months. The analytical technique applied was ICP OES and the method conditions were optimized: wavelength, linearity, signal background ratio, detection and quantification limits. Data obtained in this work will contribute to evaluate the presence of barium at CEA region and nearby in order to compare it with current Brazilian regulations. (author)

  13. Determination of barium in surface and ground waters at Centro Experimental Aramar area

    International Nuclear Information System (INIS)

    Matoso, Erika; Cadore, Solange

    2015-01-01

    Barium can be found in waters up to 1 mg L -1 and came from natural sources such as sedimentary rocks erosion rich in feldspar and barite. Also anthropogenic activities can release this element such as oil and gas industry, agricultural defensives, chemical industry and waste disposal. At high doses, barium can be harmful to human central nervous system and can also cause high blood pressure, heart problems, fatigue and anxiety. The water potability defined by Brazilian's Ministry of Healthy sets barium concentration up to 0.7 mg L -1 and official regulation defines the same limit of this element to superficial waters (according CONAMA resolution 357/2005) and ground waters (Sao Paulo state regulation). In this work, barium was analyzed monthly in superficial waters from 4 different sampling locations, located in a ratio of 10-km-long from Centro Experimental Aramar (CEA) at Ipanema River, during one year, in order to evaluate the river in different conditions (seasons, temperature and rain period). The ground water was collected every six months. The analytical technique applied was ICP OES and the method conditions were optimized: wavelength, linearity, signal background ratio, detection and quantification limits. Data obtained in this work will contribute to evaluate the presence of barium at CEA region and nearby in order to compare it with current Brazilian regulations. (author)

  14. Effect of barium-coated halloysite nanotube addition on the cytocompatibility, mechanical and contrast properties of poly(methyl methacrylate cement

    Directory of Open Access Journals (Sweden)

    Jammalamadaka U

    2017-06-01

    Full Text Available Uday Jammalamadaka,1 Karthik Tappa,1 Jeffery A Weisman,1 James Connor Nicholson,2 David K Mills1,3 1Center for Biomedical Engineering and Rehabilitation Science, 2Nanosystems Engineering, 3The School of Biological Sciences, Louisiana Tech University, Ruston, LA, USA Abstract: Halloysite nanotubes (HNTs were investigated as a platform for tunable nanoparticle composition and enhanced opacity in poly(methyl methacrylate (PMMA bone cement. Halloysite has been widely used to increase the mechanical properties of various polymer matrices, in stark contrast to other fillers such as barium sulfate that provide opacity but also decrease mechanical strength. The present work describes a dry deposition method for successively fabricating barium sulfate nanoparticles onto the exterior surface of HNTs. A sintering process was used to coat the HNTs in barium sulfate. Barium sulfate-coated HNTs were then added to PMMA bone cement and the samples were tested for mechanical strength and tailored opacity correlated with the fabrication ratio and the amount of barium sulfate-coated HNTs added. The potential cytotoxic effect of barium-coated HNTs in PMMA cement was also tested on osteosarcoma cells. Barium-coated HNTs were found to be completely cytocompatible, and cell proliferation was not inhibited after exposure to the barium-coated HNTs embedded in PMMA cement. We demonstrate a simple method for the creation of barium-coated nanoparticles that imparted improved contrast and material properties to native PMMA. An easy and efficient method for coating clay nanotubes offers the potential for enhanced imaging by radiologists or orthopedic surgeons. Keywords: barium, bone cement, halloysite, imaging, PMMA, sintering

  15. USE OF GC-MS/COMBUSTION/IRMS TO IDENTIFY AND DETERMINE THE STABLE CARBON ISOTOPIC RATIO OF INDIVIDUAL LIPIDS

    Science.gov (United States)

    A system that couples a gas chromatograph (GC) via a split to a quadrapole mass spectrometer (MS) and, through a combustion interface, to an isotope ratio mass spectrometer (IRMS) allows the simultaneous detection of electron impact mass spectra and stable carbon isotope ratio an...

  16. 75 FR 20625 - Barium Chloride From China

    Science.gov (United States)

    2010-04-20

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-149 (Third Review)] Barium Chloride From China AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject review. DATES: Effective Date: April 9, 2010. FOR FURTHER INFORMATION CONTACT: Amy Sherman (202-205-3289...

  17. Rheological properties of potassium barium borate glasses

    NARCIS (Netherlands)

    Szwejda, K.A.; Vogel, D.L.; Stevels, J.M.

    1973-01-01

    Several series of potassium barium borate glasses have been investigated as to their rheological properties. It has been found, that all these glasses show deviations from ‘Newtonian’ behaviour below temperatures corresponding to viscosities of 1010 poises. The activation energies of viscous flow

  18. Barium swallow study in routine clinical practice: a prospective study in patients with chronic cough.

    Science.gov (United States)

    Nin, Carlos Shuler; Marchiori, Edson; Irion, Klaus Loureiro; Paludo, Artur de Oliveira; Alves, Giordano Rafael Tronco; Hochhegger, Daniela Reis; Hochhegger, Bruno

    2013-01-01

    To assess the routine use of barium swallow study in patients with chronic cough. Between October of 2011 and March of 2012, 95 consecutive patients submitted to chest X-ray due to chronic cough (duration > 8 weeks) were included in the study. For study purposes, additional images were obtained immediately after the oral administration of 5 mL of a 5% barium sulfate suspension. Two radiologists systematically evaluated all of the images in order to identify any pathological changes. Fisher's exact test and the chi-square test for categorical data were used in the comparisons. The images taken immediately after barium swallow revealed significant pathological conditions that were potentially related to chronic cough in 12 (12.6%) of the 95 patients. These conditions, which included diaphragmatic hiatal hernia, esophageal neoplasm, achalasia, esophageal diverticulum, and abnormal esophageal dilatation, were not detected on the images taken without contrast. After appropriate treatment, the symptoms disappeared in 11 (91.6%) of the patients, whereas the treatment was ineffective in 1 (8.4%). We observed no complications related to barium swallow, such as contrast aspiration. Barium swallow improved the detection of significant radiographic findings related to chronic cough in 11.5% of patients. These initial findings suggest that the routine use of barium swallow can significantly increase the sensitivity of chest X-rays in the detection of chronic cough-related etiologies.

  19. Specification analysis of plutonium fuels for non-metallic impurities. I. Estimation of carbon

    Energy Technology Data Exchange (ETDEWEB)

    Rizvi, G H; Sethuraman, P R; Venkataramana, P; Natarajan, P R

    1975-01-01

    An analytical method for the estimation of carbon in plutonium samples in the range of 10-400 ..mu..g by conductometry has been developed. In the first step of the method, the entire carbon in sample is converted into CO/sub 2/ which in the second step is completely absorbed in barium hydroxide solution in conductivity of the solution.

  20. Investigation on the effects of milling atmosphere on synthesis of barium ferrite/magnetite nanocomposite

    NARCIS (Netherlands)

    Molaei, M.J.; Ataie, A.; Raygan, S.; Picken, S.J.

    2011-01-01

    In this research, barium ferrite /magnetite nanocomposites synthesized via a mechano-chemical route. Graphite was used in order to reduce hematite content of barium ferrite to magnetite to produce a magnetic nanocomposite. The effects of processing conditions on the powder characteristics were

  1. Edge detection of barium-filled stomach picture by one-dimensional collation method

    International Nuclear Information System (INIS)

    Nakamura, Shizuo

    1983-01-01

    The method for the contour edge detection of barium- filled stomach pictures by X-ray for the automatic screening is described using computer technique. It is necessary for the automatic screening of barium- filling pictures to detect accurately the outline of stomachs because the analysis of repletion pictures is performed by checking the disorder of marginal contours and abnormal stomach shapes. However, the detection of the coutour lines is difficult to be successful for the reason that the contrast of stomach pictures to background is low, a stomach is not necessarily filled completely with barium and the shadow of barium flowing into intestines is superimposed on stomach images and the shading is likely to occur. The engineering processing against these problems is not yet solved. In order to reduce the noise due to differential operator, the proposed method determines the boundary of a thing generally by the threshold value of density, and defines the edge of the thing from the differential waveform of density in the vicinity of the boundary. In addition, the method corrects the detection error caused by the local nonconformity of parameters by comparing the edges between the adjacent lines. As a result, in spite of its simple algorithm, the edges with good continuity and less noise can be detected, and the method is not much affected by shading. This method was found to be applicable to the images of others than stomachs. The extraction of the contour of barium- filling pictures requires the high level recognition processing instead of the simple conditioning. (Wakatsuki, Y.)

  2. Observation of a barium xenon exciplex within a large argon cluster.

    Science.gov (United States)

    Briant, M; Gaveau, M-A; Mestdagh, J-M

    2010-07-21

    Spectroscopic measurements provide fluorescence and excitation spectra of a single barium atom codeposited with xenon atoms on argon clusters of average size approximately 2000. The spectra are studied as a function of the number of xenon atoms per cluster. The excitation spectrum with approximately 10 xenon atoms per cluster is qualitatively similar to that observed when no xenon atom is present on the cluster. It consists of two bands located on each side of the 6s6p (1)P-6s(2) (1)S resonance line of the free barium. In contrast, the fluorescence spectrum differs qualitatively since a barium-xenon exciplex is observed, which has no counterpart in xenon free clusters. In particular an emission is observed, which is redshifted by 729 cm(-1) with respect to the Ba(6s6p (1)P-6s(2) (1)S) resonance line.

  3. Correlation between Timed Barium Esophagogram and the Eckardt Stage in Achalasia

    Directory of Open Access Journals (Sweden)

    Waraporn Boonsomjint, M.D.

    2018-01-01

    Full Text Available Objective: To evaluate the correlation of timed barium esophagogram (TBE parameters and the Eckardt stage in patients with achalasia. Methods: This prospective study was done in 29 adult achalasia patients who underwent TBE and were assessed for clinical symptoms according to the Eckardt stage. The association between the Eckardt stage and TBE parameters including the height and the width of barium column, esophageal emptying between 1 and 5 minutes, which was calculated by comparing the area of barium column and esophageal emptying between 0 and 5 minutes, which was calculated from the relative changes in ingested volume to estimated volume of barium column on the 5-min image and this was calculated by using Kruskal-Wallis test. Comparison of mean emptied volume at 1 min. image and mean emptied volume between 1 and 5 minutes was done by using paired samples t-tests. Results: There was a significant difference in the amount of emptied volume at 1 min image (mean = 118.27, SD = 31.1 and emptied volume between 1 min and 5 min images (mean = 11.41, SD = 9.4; t(27 =15.375, p < 0.001. Statistically significant difference in esophageal emptying between 1 and 5 minutes across the Eckardt stages was found (H=8.115, 3 d.f., p=0.044. The difference was statistically significant between the Eckardt stage 2 and 3 (p=0.039. There were no statistically significant differences in other TBE parameters across the Eckardt stages. Conclusion: No statistically significant difference in TBE parameters across the Eckardt stages was found in the present study. However, TBE is a useful objective method to assess esophageal emptying in patients with achalasia. Interpretation of TBE should be standardized. Calculation of esophageal emptying should include the amount of barium emptied from the esophagus in the first minute.

  4. The effect of barium temperature on esophageal and castric motility in dogs: a fluoroscopic study

    International Nuclear Information System (INIS)

    Eville, P.; Ackerman, N.

    1984-01-01

    The influence of barium temperature on canine esophageal transit time and gastric motility were studied fluoroscopically. Micropulverized barium sulfate (30% wt/vol) at 35°F, 70°F, and 100°F was given orally to each of five dogs with a minimum of two hours between each temperature. Esophageal transit times ranged from 4 to 9.67 seconds, and gastric contractions average four per minute. Barium temperature had no significant effect on either esophageal transit time or gastric motility

  5. Colonic transit time in patient with slow-transit constipation: Comparison of radiopaque markers and barium suspension method

    International Nuclear Information System (INIS)

    Xu Huimin; Han Jiagang; Na Ying; Zhao Bo; Ma Huachong; Wang Zhenjun

    2011-01-01

    Background: Colonic transit study provides valuable information before surgical treatment is considered for patient with constipation. The radiopaque markers method is the most common way for evaluating colon transit time. The aim of this study is to compare the barium suspension with the radiopaque makers to assess the colonic mobility in patient with constipation. Methods: Colonic transit time was measured in 11 female patients with slow-transit constipation using both radiopaque markers and barium suspension method. In radiopaque markers method, the patient ingested 20 markers on the first day, and an abdominal radiograph was performed every 24 h until 80% markers were excreted. In barium suspension method, the patient swallowed up to 50 ml of 200% (w/v) barium meal. The abdominal radiographs were taken at the same time point as the former. Results: The total or segmental colonic transit time were obviously prolonged in all patients. Segmental transits time spent in the right colon, left colon and rectosigmoid for radiopaque markers and barium suspension method was, respectively, 30 ± 6 h and 34 ± 7 h; 38 ± 9 h and 32 ± 6 h; 40 ± 8 h and 38 ± 10 h. In the radiopaque markers method, total colonic transit time was 108 ± 14 h and it was 103 ± 13 h in the barium suspension method (P > 0.05). Conclusion: The barium suspension and radiopaque markers gave the similar results for colonic transit time. The barium suspension was a simple and cheap method for evaluating the colonic mobility.

  6. Simulation of dual carbon-bromine stable isotope fractionation during 1,2-dibromoethane degradation.

    Science.gov (United States)

    Jin, Biao; Nijenhuis, Ivonne; Rolle, Massimo

    2018-06-01

    We performed a model-based investigation to simultaneously predict the evolution of concentration, as well as stable carbon and bromine isotope fractionation during 1,2-dibromoethane (EDB, ethylene dibromide) transformation in a closed system. The modelling approach considers bond-cleavage mechanisms during different reactions and allows evaluating dual carbon-bromine isotopic signals for chemical and biotic reactions, including aerobic and anaerobic biological transformation, dibromoelimination by Zn(0) and alkaline hydrolysis. The proposed model allowed us to accurately simulate the evolution of concentrations and isotope data observed in a previous laboratory study and to successfully identify different reaction pathways. Furthermore, we illustrated the model capabilities in degradation scenarios involving complex reaction systems. Specifically, we examined (i) the case of sequential multistep transformation of EDB and the isotopic evolution of the parent compound, the intermediate and the reaction product and (ii) the case of parallel competing abiotic pathways of EDB transformation in alkaline solution.

  7. Measurement of carbon-14 in hydrological samples

    International Nuclear Information System (INIS)

    Hussain, S.D.

    1991-11-01

    Thermal neutrons produced by cosmic rays or nuclear weapon tests interact with atmospheric nitrogen resulting in the formation of radiocarbon which, after oxidation into carbon dioxide, follows the natural carbon cycle. The partial pressure of carbon dioxide in the soil is several times that in the atmosphere due to plant root respiration and decay of organic matter. Water absorbs biogenic carbon dioxide while percolating through the unsaturated zone. The carbon content of groundwater is mainly in the form of bicarbonate ions. The extraction of carbon from water sample as barium carbonate is carried out in the field. Benzene is synthesised from the carbonate sample. The activity of radiocarbon in the synthesised benzene is determined by using a liquid scintillation analyzer. Details of sampling procedure, benzene synthesis, counter calibration and treatment of sample data have been given. 7 figs. (author)

  8. High temperature impedance spectroscopy of barium stannate ...

    Indian Academy of Sciences (India)

    (M = Ba, Sr, Ca and Pb). ... Barium stannate (BaSnO3) is a cubic pervoskite oxide com- .... were gold-sputtered and scanned in different regions using .... de ions. Water insertion into the oxide structure can be re- presented as the process of ...

  9. Carbon and oxygen stable isotope and trace element studies in speleothems and across the J-K boundary, Central Italy

    International Nuclear Information System (INIS)

    Kudielka, G.

    2001-07-01

    Carbon and Oxygen stable isotope ratios of carbonates decisively depend on fractionation during physicochemical processes. Therefore, they represent a powerful tool to derive information on past conditions under which the carbonates formed. Isotope ratio mass spectrometry (IRMS) offers a large range of applications. This thesis presents two projects based upon investigation of carbon and oxygen stable isotope ratios combined with trace element abundances (determined by instrumental neutron activation analysis, INAA) in carbonates. (1) Palaeoclimatic investigation on speleothems from central Italy. Four speleothems from Grotta Grande del Vento, central Italy, were analyzed for stable isotope ratios and trace element abundances, and age dated to obtain a chronologically reliable stable isotope profile. The speleothems were sampled by means of a dental drill to gain a stable isotope profile with a 0.5 mm resolution, trace element abundances have been performed by INAA every 0.5 cm, and the samples for age dating were picked according to remarkable features in the stable isotope trends and analyzed by TIMS. The record covers the period from 93 ka until the early holocene with a hiatus lasting from 75 ka until 65.0 ka. Speleothem growth during the last glacial indicates moderate conditions in the Frasassi region back then. Comparison with speleothems from Ireland, France and northern Italy reveal a north-south slope in d18O, indicating, that the rain over central Italy mainly originates from the North Atlantic. Depletion of moisture in d18O during its continental trajectory is due to rainout, which primarily extracts the heavy isotopes. The stable isotope record is in good agreement with the high-resolution speleothem record from Soreq Cave, Israel. Distinct isotopic events coincide between 85 ka and 80 ka, between ∼ 60 ka and 50 ka and from the last glacial to the early holocene. An offset has been existing between the two records at any time. The speleothems of

  10. Improved thermal stability and wettability behavior of thermoplastic polyurethane / barium metaborate composites

    International Nuclear Information System (INIS)

    Baştürka, Emre; Madakbaş, Seyfullah; Kahraman, Memet Vezir

    2016-01-01

    In this paper, it was targeted to the enhance thermal stability and wettability behavior of thermoplastic polyurethane (TPU) by adding barium metaborate. TPU-Barium metaborate composites were prepared by adding various proportions of barium metaborate to TPU. The chemical structures of the composites were characterised by fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. All prepared composites have extremely high Tg and thermal stability as determined from DSC and TGA analysis. All composite materials have the Tg ranging from 15 to 35 °C. The surface morphologies of the composites were investigated by a scanning electron microscopy. Mechanical properties of the samples were characterized with stress-strain test. Hydrophobicity of the samples was determined by the contact angle measurements. The obtained results proved that thermal, hydrophobic and mechanical properties were improved. (author)

  11. Improved thermal stability and wettability behavior of thermoplastic polyurethane / barium metaborate composites

    Energy Technology Data Exchange (ETDEWEB)

    Baştürka, Emre; Madakbaş, Seyfullah; Kahraman, Memet Vezir, E-mail: smadakbas@marmara.edu.tr [Department of Chemistry, Marmara University, Istanbul (Turkey)

    2016-03-15

    In this paper, it was targeted to the enhance thermal stability and wettability behavior of thermoplastic polyurethane (TPU) by adding barium metaborate. TPU-Barium metaborate composites were prepared by adding various proportions of barium metaborate to TPU. The chemical structures of the composites were characterised by fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. All prepared composites have extremely high Tg and thermal stability as determined from DSC and TGA analysis. All composite materials have the Tg ranging from 15 to 35 °C. The surface morphologies of the composites were investigated by a scanning electron microscopy. Mechanical properties of the samples were characterized with stress-strain test. Hydrophobicity of the samples was determined by the contact angle measurements. The obtained results proved that thermal, hydrophobic and mechanical properties were improved. (author)

  12. Deposition barium titanate (BaTiO3) doped lanthanum with chemical solution deposition

    International Nuclear Information System (INIS)

    Iriani, Y.; Nurhadi, N.; Jamaludin, A.

    2016-01-01

    Deposition of Barium Titanate (BaTiO 3 ) thin films used Chemical Solution Deposition (CSD) method and prepared with spin coater. BaTiO 3 is doped with lanthanum, 1%, 2%, and 3%. The thermal process use annealing temperature 900°C and holding time for 3 hours. The result of characterization with x-ray diffraction (XRD) equipment show that the addition of La 3+ doped on Barium Titanate caused the change of angle diffraction.The result of refine with GSAS software shows that lanthanum have been included in the structure of BaTiO 3 . Increasing mol dopant La 3+ cause lattice parameter and crystal volume become smaller. Characterization result using Scanning Electron Microscopy (SEM) equipment show that grain size (grain size) become smaller with increasing mole dopant (x) La 3+ . The result of characterization using Sawyer Tower methods show that all the samples (Barium Titanante and Barium Titanate doped lanthanum) are ferroelectric material. Increasing of mole dopant La 3+ cause smaller coercive field and remanent polarization increases. (paper)

  13. Stable and sensitive flow-through monitoring of phenol using a carbon nanotube based screen printed biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Alarcon, G; Guix, M; Ambrosi, A; Merkoci, A [Nanobioelectronics and Biosensors Group, Catalan Institute of Nanotechnology, Campus UAB, 08193 Bellaterra, Barcelona, Catalonia (Spain); Ramirez Silva, M T [Departamento de Quimica, Universidad Autonoma Metropolitana Iztapalapa, 09340 Mexico Distrito Federal (Mexico); Palomar Pardave, M E, E-mail: arben.merkoci.icn@uab.es [Departamento de Materiales, Universidad Autonoma Metropolitana, Azcapotzalco, 02200 Mexico Distrito Federal (Mexico)

    2010-06-18

    A stable and sensitive biosensor for phenol detection based on a screen printed electrode modified with tyrosinase, multiwall carbon nanotubes and glutaraldehyde is designed and applied in a flow injection analytical system. The proposed carbon nanotube matrix is easy to prepare and ensures a very good entrapment environment for the enzyme, being simpler and cheaper than other reported strategies. In addition, the proposed matrix allows for a very fast operation of the enzyme, that leads to a response time of 15 s. Several parameters such as the working potential, pH of the measuring solution, biosensor response time, detection limit, linear range of response and sensitivity are studied. The obtained detection limit for phenol was 0.14 x 10{sup -6} M. The biosensor keeps its activity during continuous FIA measurements at room temperature, showing a stable response (RSD 5%) within a two week working period at room temperature. The developed biosensor is being applied for phenol detection in seawater samples and seems to be a promising alternative for automatic control of seawater contamination. The developed detection system can be extended to other enzyme biosensors with interest for several other applications.

  14. Stable and sensitive flow-through monitoring of phenol using a carbon nanotube based screen printed biosensor

    International Nuclear Information System (INIS)

    Alarcon, G; Guix, M; Ambrosi, A; Merkoci, A; Ramirez Silva, M T; Palomar Pardave, M E

    2010-01-01

    A stable and sensitive biosensor for phenol detection based on a screen printed electrode modified with tyrosinase, multiwall carbon nanotubes and glutaraldehyde is designed and applied in a flow injection analytical system. The proposed carbon nanotube matrix is easy to prepare and ensures a very good entrapment environment for the enzyme, being simpler and cheaper than other reported strategies. In addition, the proposed matrix allows for a very fast operation of the enzyme, that leads to a response time of 15 s. Several parameters such as the working potential, pH of the measuring solution, biosensor response time, detection limit, linear range of response and sensitivity are studied. The obtained detection limit for phenol was 0.14 x 10 -6 M. The biosensor keeps its activity during continuous FIA measurements at room temperature, showing a stable response (RSD 5%) within a two week working period at room temperature. The developed biosensor is being applied for phenol detection in seawater samples and seems to be a promising alternative for automatic control of seawater contamination. The developed detection system can be extended to other enzyme biosensors with interest for several other applications.

  15. Indentation plasticity of barium titanate single crystals: Dislocation influence on ferroelectric domain walls

    International Nuclear Information System (INIS)

    Liu, D.; Chelf, M.; White, K.W.

    2006-01-01

    The plastic behaviors of barium titanate (001) and (110) single crystals are studied with atomic force microscopy and piezoresponse force microscopy (PFM) following nanoindendation damage. Plastic deformation mechanisms of ferroelectric barium titanate single crystals are discussed with a focus on the interaction between PFM response and dislocation activities. Nanoindentation tests indicate that the theoretical strength is approached prior to the first pop-in event, consistent with the creation of dislocation nucleation sites required for the onset of plasticity. Surface topographic and piezoelectric analyses indicate that pile-ups around indents result from dislocation activities on the primary slip system, {110} pc pc . The more complex indentation-induced domain patterns observed on (110) barium titanate are also discussed

  16. The medical effects of radioactive fall-out: role of stable end-products

    International Nuclear Information System (INIS)

    Burrows, B.A.; Cardarelli, J.C.; Boling, E.A.; Sinex, F.M.

    1980-01-01

    To summarize, from preliminary observations on the possible effects of radioactive fall-out, it may be inferred that in addition to the secondary products of ionizing irradiation per se, the stable end-products of the transmutation of certain radionuclides may adversely influence cellular metabolism, including mutagenesis. The discussion of the possible role of intracellular barium as an end-product of 137Cs decay is offered as an example of an unpredictable number of broad ecological, as well as the more limited medical, effects that may be of both clinical and climatological significance

  17. Fabrication and electrical characterization of 15% yttrium-doped barium zirconate-nitrate freeze drying method combined with vacuum heating

    International Nuclear Information System (INIS)

    Imashuku, Susumu; Uda, Tetsuya; Nose, Yoshitaro; Awakura, Yasuhiro

    2011-01-01

    Research highlights: → Very fine 15% yttrium-doped barium zirconate powder of particle size about 30 nm was obtained by synthesizing at 500 deg. C in vacuum from powder mixed by the nitrate freeze-drying method. → Large and homogeneous grains of 15% yttrium-doped barium zirconate were easily obtained using the synthesized powder. → Grain boundary resistance was not inversely proportional to the grain size as theoretically expected. → Specific grain boundary conductivity varies with samples because impurities and/or evaporation loss of barium oxide might affect the grain-boundary resistance in 15% yttrium-doped barium zirconate. - Abstract: We applied a nitrate freeze-drying method to obtain a fine synthesized powder of 15% yttrium-doped barium zirconate. Fine 15% yttrium-doped barium zirconate powder of particle size about 30 nm was obtained by synthesizing at 500 deg. C in vacuum from a powder mixed by the nitrate freeze-drying method. However, we could not obtain such fine powder by synthesizing in air. Using the powder synthesized in vacuum, large and homogeneous grains of 15% yttrium-doped barium zirconate were easily obtained after sintering. Then, the bulk and grain boundary resistance were evaluated by AC 2-terminal measurement of sample in the form of bar and pellet and DC 4-terminal measurement of bar-shape sample. The grain boundary resistance was not inversely proportional to the grain size as theoretically expected. We concluded that specific grain boundary conductivity varies with samples. Some impurities, evaporation loss of barium oxide and/or other unexpected reasons might affect the grain boundary resistance in 15% yttrium-doped barium zirconate.

  18. The application of stable carbon isotope ratios as water quality indicators in coastal areas of Karachi, Pakistan

    International Nuclear Information System (INIS)

    Qureshi, R.M.; Mashiatullah, A.; Javed, T.; Tasneem, M.A.; Sajjad, M.I.; Saleem, M.; Khan, S.H.; Rizvi, S.H.N.; Siddiqui, S.A.; Qari, R.

    1998-01-01

    Stable carbon isotope ratios (δ 13 C) of total dissolved inorganic carbon (TDIC), total inorganic and organic carbon in bottom sediments, as well as sea plants in polluted water sources, non-polluted Karachi Sea water and pollution recipients are used to elaborate pollution scenario of shallow marine environment off Karachi coast. These results are supplemented with stable isotope composition of nitrogen (δ 15 N) in seaweeds and mangroves, toxic/trace metal concentration in sea-bottom sediments, total Coliform bacterial population, electrical conductivity, temperature and turbidity. Isotopic data shows that the mangrove ecosystem and the tidal fluctuations play a key role in controlling contamination inventories in shallow sea water off Karachi coast, specifically the Manora Channel. The Karachi harbour zone is found to be the most heavily polluted marine site in Manora channel during high as well as low tide regimes. Significant concentrations of toxic metals such as Pb, Ni, Cr, Zn, V, U are observed in off-shore sediments of Karachi coast. The results show that sewage and industrial wastes are the main sources of heavy metal pollution in Karachi harbour, Manora Channel exit zone and the southeast coast. However, as compared to other coastal areas, the Karachi coast is moderately polluted. Studies suggest incorporation of quick remedial measures to combat pollution in shallow marine environments off Karachi Coast. (author)

  19. 75 FR 19657 - Barium Chloride From China

    Science.gov (United States)

    2010-04-15

    ... China AGENCY: United States International Trade Commission. ACTION: Notice of Commission determination... China. SUMMARY: The Commission hereby gives notice that it will proceed with a full review pursuant to... antidumping duty order on barium chloride from China would be likely to lead to continuation or recurrence of...

  20. Stable carbon and oxygen isotope signatures in molluscan shells under ocean acidification

    Science.gov (United States)

    Nishida, K.; Hayashi, M.; Suzuki, A.; Sato, M.; Nojiri, Y.

    2017-12-01

    Stable carbon and oxygen isotope compositions (δ13C, δ18O) of biogenic carbonate have been widely used for many paleoclimate, paleoecological, and biomineralization studies. δ13C of molluscan shells reflects the mixing of δ13C of dissolved inorganic carbon (DIC) of seawater and respiratory carbon. Previous studies reported physiological effects on molluscs by ocean acidification, and thus the metabolic changes could potentially appear in shell δ13C as changes in a fraction of two carbon sources. In addition, shell δ18O, a commonly used proxy of seawater temperature and seawater δ18O, is also affected by seawater carbonate chemistry. As changes in the marine carbonate system, such as pH and pCO2, have occurred in the past 300 million years, to estimate pH effect on paleotemperature reconstruction is important. Here, we experimentally examined acidification effects on shell δ13C and δ18O of two species of clams for understanding of environmental and physiological proxies. Juvenile specimens of bloody clam Scapharca broughtonii and Japanese surf clam Pseudocardium sachalinense were cultured at five (400, 600, 800, 1000, and 1200 µatm, P. sachalinense) or six (280, 400, 600, 800, 1000, and 1200 µatm, S. broughtonii) different pCO2 levels using CO2 control system of the Demonstration Laboratory, MERI, Japan. Significant negative correlations between shell δ13C and pH appeared in S. broughtonii, which showed non-significant pH effects on calcification, and the slope of the relationship of shell carbonate was lower than that of seawater DIC. On the other hand, in P. sachalinense which showed a decrease in calcification at low-pH treatment, the slopes of the relationship between shell δ13C and pH was roughly the same as that of seawater DIC. Thus, the extrapallial fluid of P. sachalinense might more strongly affected by acidified seawater than S. broughtonii. The results of two species might be attributable to differences in physiological responses to

  1. Esophageal intramural pseudodiverticulosis characterized by barium esophagography: a case report

    LENUS (Irish Health Repository)

    O'Connor, Owen J

    2010-05-21

    Abstract Introduction Esophageal intramural pseudodiverticulosis is a rare condition characterized by the dilatation of the submucosal glands. Case presentation We present a case of esophageal intramural pseudodiverticulosis in a 72-year-old Caucasian man who presented with dysphagia and with a background history of alcohol abuse. An upper gastrointestinal endoscopy of our patient showed an esophageal stricture with abnormal mucosal appearances, but no malignant cells were seen at biopsy. Appearances on a barium esophagram were pathognomonic for esophageal intramural pseudodiverticulosis. Conclusion We demonstrate the enduring usefulness of barium esophagography in the characterization of abnormal mucosal appearances at endoscopy.

  2. Relict thermokarst carbon source kept stable within gas hydrate stability zone of the South Kara Sea

    Science.gov (United States)

    Portnov, A.; Mienert, J.; Winsborrow, M.; Vadakkepuliyambatta, S.; Semenov, P.

    2017-12-01

    Substantial shallow sources of carbon can exist in the South Kara Sea shelf, extending offshore from the permafrost areas of Yamal Peninsula and the Polar Ural coast. Our study presents new evidence for >250 buried relict thermokarst units. These amalgamated thawing wedges formed in the uppermost permafrost of the past and are still recognizable in today's non-permafrost areas. Part of these potential carbon reservoirs are kept stable within the South Kara Sea gas hydrate stability zone (GHSZ). We utilize an extensive 2D high-resolution seismic dataset, collected in the South Kara Sea in 2005-2006 by Marine Arctic Geological Expedition (MAGE), to map distinctive U-shaped units that are acoustically transparent. These units appear all over the study area in water depths 50-250 m. Created by thermal erosion into Cretaceous-Paleogene bedrock, they are buried under the younger glacio-marine deposits and reach hundreds of meters wide and up to 100 meters thick. They show the characteristics of relict thermokarst, generated during ancient episode(s) of sea level regression of the South Kara Sea. These thermokarst units are generally limited by the Upper Regional Unconformity, which is an erosional horizon created by several glaciation events during the Pleistocene. On land, permafrost is known to sequester large volumes of carbon, half of which is concentrated within thermokarst structures. Based on modern thermokarst analogues we demonstrate with our study that a significant amount of organic carbon can be stored under the Kara Sea. To assess the stability of these shallow carbon reservoirs we carried out GHSZ modeling, constrained by geochemical analyses, temperature measurements and precise bathymetry. This revealed a significant potential for a GHSZ in water depths >225 m. The relict thermokast carbon storage system is stable under today's extremely low bottom water temperatures ( -1.7 °C) that allows for buried GHSZ, located tens of meters below the seabed

  3. Barium swallow study in routine clinical practice: a prospective study in patients with chronic cough

    Directory of Open Access Journals (Sweden)

    Carlos Shuler Nin

    2013-12-01

    Full Text Available OBJECTIVE: To assess the routine use of barium swallow study in patients with chronic cough.METHODS: Between October of 2011 and March of 2012, 95 consecutive patients submitted to chest X-ray due to chronic cough (duration > 8 weeks were included in the study. For study purposes, additional images were obtained immediately after the oral administration of 5 mL of a 5% barium sulfate suspension. Two radiologists systematically evaluated all of the images in order to identify any pathological changes. Fisher's exact test and the chi-square test for categorical data were used in the comparisons.RESULTS: The images taken immediately after barium swallow revealed significant pathological conditions that were potentially related to chronic cough in 12 (12.6% of the 95 patients. These conditions, which included diaphragmatic hiatal hernia, esophageal neoplasm, achalasia, esophageal diverticulum, and abnormal esophageal dilatation, were not detected on the images taken without contrast. After appropriate treatment, the symptoms disappeared in 11 (91.6% of the patients, whereas the treatment was ineffective in 1 (8.4%. We observed no complications related to barium swallow, such as contrast aspiration.CONCLUSIONS: Barium swallow improved the detection of significant radiographic findings related to chronic cough in 11.5% of patients. These initial findings suggest that the routine use of barium swallow can significantly increase the sensitivity of chest X-rays in the detection of chronic cough-related etiologies.

  4. Evidence against barium in the mushroom Trogia venenata as a cause of sudden unexpected deaths in Yunnan, China.

    Science.gov (United States)

    Zhang, Ying; Li, Yanchun; Wu, Gang; Feng, Bang; Yoell, Shanze; Yu, Zefen; Zhang, Keqin; Xu, Jianping

    2012-12-01

    This study examined barium concentrations in the mushroom Trogia venenata, the leading culprit for sudden unexpected deaths in Yunnan, southwest China. We found that barium concentrations in T. venenata from Yunnan were low and comparable to other foods, inconsistent with barium concentrations in this mushroom as a significant contributor to these deaths.

  5. Barium borate nanorod decorated reduced graphene oxide for optical power limiting applications

    Science.gov (United States)

    Muruganandi, G.; Saravanan, M.; Vinitha, G.; Jessie Raj, M. B.; Sabari Girisun, T. C.

    2018-01-01

    By simple hydrothermal method, nanorods of barium boate were successfully loaded on reduced graphene oxide sheets. Powder XRD confirms the incorporation of barium borate (2θ = 29°, (202)) along with the transition of graphene oxide (2θ = 12°, (001)) into reduced graphene oxide (2θ = 25°, (002)). In the FTIR spectra, presence of characteristic absorption peaks of rGO (1572 and 2928 cm-1) and barium borate (510, 760 and 856 cm-1) further evidences the formation of BBO:rGO nanocomposite. FESEM images potray the existence of graphene sheets as thin layers and growth of barium borate as nanorods on the sheets of reduced graphene oxide. Ground state absorption studies reveal the hypsochromic shift in the absorption maxima of the graphene layers due to reduction of graphene oxide and hypochromic shift in the absorbance intensity due to the inclusion of highly transparent barium bortae. The photoluminescence of BBO:rGO shows maximum emission in the UV region arising from the direct transitions involving the valence band and conduction band in the band gap region. Z-scan technique using CW diode pumped Nd:YAG laser (532 nm, 50 mW) exposes that both nanocomposite and individual counterpart possess saturable absorption and self-defocusing behavior. Third-order nonlinear optical coefficients of BBO:rGO nanocomposite is found to be higher than bare graphene oxide. In particular the nonlinear refractive index of nanocomposite is almost four times higher than GO which resulted in superior optical power limiting action. Strong nonlinear refraction (self-defocusing) and lower onset limiting thershold makes the BBO:rGO nanocomposite preferable candidate for laser safety devices.

  6. Granulomatous colitis: findings on double contrast barium enema and follow-up studies

    International Nuclear Information System (INIS)

    Song, Jong Gi; Han, Joon Koo; Kim, Seung Hoon; Choo, Sung Wook; Kim, Seung Cheol; Choi, Byung Ihn

    1995-01-01

    To evaluate the radiologic findings of granulomatous colitis on double contrast barium enema and changes on follow-up studies. Serial double contrast barium enema of six patients with granulomatous colitis confirmed by endoscopic biopsy were reviewed. We analyzed the radiologic findings and their follow-up changes, including aphthous ulcers, lymphoid hyperplasia, deep ulcers, cobble stone appearance, geographic ulcers, asymmetric involvement of ulcers, skip lesions, sinus tract, fistula formation, pseudosacculation, focal stricture, and small bowel involvement. Pretreatment double contrast barium enema findings were aphthous ulcers in five patients, deep ulcer in six, cobble stone appearance in five, longitudinal geographic ulcers in two, fistulas in one, pseudosacculations in two, focal stricture in one, and pseudopolyps in six. Also, anal ulcers were observed in two patients, asymmetric involvement of ulcers in three, skip lesions in four, and small bowel involvement in five in five patients proved to have inactive disease after treatment, aphthous ulcers and deep ulcers disappeared. Geographic ulcers of two patients and anal ulcer of one patients decreased in size or depth. Pseudosacculation in one patient disappeared. Pseudopolyps decreased in two patients, increased in one, and decreased after increase in two. One patient whose disease remained active after treatment showed maintenance or increase of ulcers or fistula. And their pseudosacculation or focal stricture unchanged and pseudopolyps decreased. The major radiologic findings of chronic granulomatous colitis on double contrast barium enema are aphthous ulcer, deep ulcer, cobble stone appearance, discontinuity of the lesion and coexistence of ulcers and pseudopolyps. And, double contrast barium enema is good follow-up modality because its findings correlate with clinical course of the granulomatous colitis after treatment

  7. A surface-chemistry study of barium ferrite nanoplates with DBSa-modified surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lisjak, Darja, E-mail: darja.lisjak@ijs.si [Jožef Stefan Institute, Ljubljana (Slovenia); Ovtar, Simona; Kovač, Janez [Jožef Stefan Institute, Ljubljana (Slovenia); Gregoratti, Luca; Aleman, Belen; Amati, Matteo [Elettra – Sincrotrone Trieste S.C.p.A. di interesse nazionale, Trieste (Italy); Fanetti, Mattia [University of Nova Gorica, Nova Gorica (Slovenia); Istituto Officina dei Materiali CNR, Area Science Park, Trieste (Italy); Makovec, Darko [Jožef Stefan Institute, Ljubljana (Slovenia)

    2014-06-01

    Barium ferrite (BaFe{sub 12}O{sub 19}) is a ferrimagnetic oxide with a high magnetocrystalline anisotropy that can be exploited in magnetically aligned ceramics or films for self-biased magnetic applications. Magnetic alignment of the films can be achieved by the directed assembly of barium ferrite nanoplates. In this investigation the nanoplates were synthesized hydrothermally and suspended in 1-butanol using dodecylbenzene sulphonic acid (DBSa) as a surfactant. They were then deposited in an electric or magnetic field on flat substrates and exhibited a significant preferential alignment in the plane of the substrate, allowing a differentiation between the analysis of their basal and side planes using scanning photoelectron microscopy with a lateral resolution down to 100 nm. The surface chemistry of the nanoplates was additionally studied with X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry. For a comparison, bare barium ferrite nanoplates were also analyzed after decomposing the DBSa at 460 °C. The deviation of the surface chemistry from the stoichiometric composition was observed and the adsorption of the DBSa molecules on the nanoplates was confirmed with all three methods. Different types of bonding (physi- or chemisorption) were possible and considered with respect to the assembly of the barium ferrite nanoplates into anisotropic magnetic films.

  8. Individual-specific transgenerational marking of fish populations based on a barium dual-isotope procedure.

    Science.gov (United States)

    Huelga-Suarez, Gonzalo; Moldovan, Mariella; Garcia-Valiente, America; Garcia-Vazquez, Eva; Alonso, J Ignacio Garcia

    2012-01-03

    The present study focuses on the development and evaluation of an individual-specific transgenerational marking procedure using two enriched barium isotopes, (135)Ba and (137)Ba, mixed at a given and selectable molar ratio. The method is based on the deconvolution of the isotope patterns found in the sample into four molar contribution factors: natural xenon (Xe nat), natural barium (Ba nat), Ba135, and Ba137. The ratio of molar contributions between Ba137 and Ba135 is constant and independent of the contribution of natural barium in the sample. This procedure was tested in brown trout ( Salmo trutta ) kept in captivity. Trout were injected with three different Ba137/Ba135 isotopic signatures ca. 7 months and 7 days before spawning to compare the efficiency of the marking procedure at long and short term, respectively. The barium isotopic profiles were measured in the offspring by means of inductively coupled plasma mass spectrometry. Each of the three different isotopic signatures was unequivocally identified in the offspring in both whole eggs and larvae. For 9 month old offspring, the characteristic barium isotope signatures could also be detected in the otoliths even in the presence of a high and variable amount of barium of natural isotope abundance. In conclusion, it can be stated that the proposed dual-isotope marking is inheritable and can be detected after both long-term and short-term marking. Furthermore, the dual-isotope marking can be made individual-specific, so that it allows identification of offspring from a single individual or a group of individuals within a given fish group. © 2011 American Chemical Society

  9. The preparation of glucosa uniformly labelled with carbon-14

    International Nuclear Information System (INIS)

    Garcia Pineda, D.; Suarez, C.; Rodrigo Gonzalez, E.

    1978-01-01

    The plant, (Zea mais, L) and culture conditions for an optimun production of glucose has been chosen. To achieve the labelling of glucose, photosynthesis and carboxilation are carried on under an artificial atmosphere of 1 4CO 2 produced from 1 4C-barium carbonate. Following photosynthesis, the sugars are extracted and then the extract purified by several methods. The purified glucose is, finally, degraded and the specific radiactivity is determined in each of its carbon atoms. (author)

  10. The preparation of glucose uniformly labelled with carbon-14

    International Nuclear Information System (INIS)

    Garcia Pineda, M.D.; Suarez Contreras, C.; Rodrigo Gonzalez, M.E.

    1978-01-01

    The plant, (Zea mais, L) and culture conditions for an optimum production of glucose has been chosen. To achieve the labelling of glucose, photosynthesis and carboxylation are carried on, under an artificial atmosphere of 14CO 2 produced from 14 C -barium carbonate. Following photosynthesis the sugars are extracted, and then the extract purified by several methods. The purified glucose is finally, degraded and the specific radioactivity is determined in each of its carbon atoms. (Author) 37 refs

  11. Specification analysis of plutonium fuels for non-metallic impurities. I - estimation of carbon

    International Nuclear Information System (INIS)

    Rizvi, G.H.; Sethuraman, P.R.; Venkataramana, P.; Natarajan, P.R.

    1975-01-01

    An analytical method for the estimation of carbon in plutonium samples in the range of 10-400 μg by conductometry has been developed. In the first step of the method, the entire carbon in sample is converted into CO 2 which in the second step is completely absorbed in barium hydroxide solution in conductivity of the solution. (M.G.B.)

  12. Barium ferrite nanoparticles prepared by self-propagating low ...

    Indian Academy of Sciences (India)

    Administrator

    Kubo et al 1982; Lucchini et al 1983), hydrothermal. (Barb et al 1986), microemulsion ... combustion route employing metal oxalate precursors. In search of a suitable ... heptahydrate/barium nitrate and oxalic acid were dis- solved in minimum ...

  13. Study of decomposition kinetics of volatile β-diketonates of yttrium, barium and copper in flow reactor

    International Nuclear Information System (INIS)

    Devyatykh, G.G.; Gavrishchuk, E.M.; Gibin, A.M.; Dadanov, A.Yu.; Dzyubenko, N.G.; Kaul', A.R.; Nichiporuk, R.V.; Snezhko, N.T.; Ul'yanov, A.A.

    1990-01-01

    Heterogeneous oxidative decomposition of adduct of yttrium acetylacetonate with o-phenanthroline, copper acetylacetonate and barium dipivaloylmethanate in a flow-type reactor was carried out. The basic kinetic characteristics of chemical precipitation processes of films of yttrium, copper and barium oxides, which are components of high-temperature superconductors, were obtained. The values of activation energy of precipitation process of yttrium, copper and barium oxides constituted 76±10, 108±15, 81±12 (t 600 deg C) respectively

  14. Determination of the origin of dissolved inorganic carbon in groundwater around a reclaimed landfill in Otwock using stable carbon isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Porowska, Dorota, E-mail: dorotap@uw.edu.pl

    2015-05-15

    Highlights: • Research showed the origin of DIC in the groundwater around a reclaimed landfill. • Carbon isotope was used to evaluate the contributions of carbon from different sources. • The leachate-contaminated water was isotopically distinct from the natural groundwater. • DIC in the natural groundwater comes from organic matter and dissolution of carbonates. • In the contaminated water, DIC comes from organic matter in the aquifer and landfill. - Abstract: Chemical and isotopic analyses of groundwater from piezometers located around a reclaimed landfill in Otwock (Poland) were performed in order to trace the origin of dissolved inorganic carbon (DIC) in the groundwater. Due to differences in the isotopic composition of carbon from different sources, an analysis of stable carbon isotopes in the groundwater, together with the Keeling plot approach and a two-component mixing model allow us to evaluate the relative contributions of carbon from these sources in the groundwater. In the natural (background) groundwater, DIC concentrations and the isotopic composition of DIC (δ{sup 13}C{sub DIC}) comes from two sources: decomposition of organic matter and carbonate dissolution within the aquifer sediments, whereas in the leachate-contaminated groundwater, DIC concentrations and δ{sup 13}C{sub DIC} values depend on the degradation of organic matter within the aquifer sediments and biodegradation of organic matter stored in the landfill. From the mixing model, about 4–54% of the DIC pool is derived from organic matter degradation and 96–46% from carbonate dissolution in natural conditions. In the leachate-contaminated groundwater, about 20–53% of the DIC is derived from organic matter degradation of natural origin and 80–47% from biodegradation of organic matter stored in the landfill. Partial pressure of CO{sub 2} (P CO{sub 2}) was generally above the atmospheric, hence atmospheric CO{sub 2} as a source of carbon in DIC pool was negligible in the

  15. Stable carbon isotope response to oceanic anoxic events

    International Nuclear Information System (INIS)

    Hu Xiumian; Wang Chengshan; Li Xianghui

    2001-01-01

    Based on discussion of isotope compositions and fractionation of marine carbonate and organic carbon, the author studies the relationship between oceanic anoxic events and changes in the carbon isotope fractionation of both carbonate and organic matter. During the oceanic anoxic events, a great number of organisms were rapidly buried, which caused a kind of anoxic conditions by their decomposition consuming dissolved oxygen. Since 12 C-rich organism preserved, atmosphere-ocean system will enrich relatively of 13 C. As a result, simultaneous marine carbonate will record the positive excursion of carbon isotope. There is a distinctive δ 13 C excursion during oceanic anoxic events in the world throughout the geological time. In the Cenomanian-Turonian anoxic event. this positive excursion arrived at ∼0.2% of marine carbonate and at ∼0.4% of organic matter, respectively. Variations in the carbon isotopic compositions of marine carbonate and organic carbon record the changes in the fraction of organic carbon buried throughout the geological time and may provide clues to the changes in rates of weathering and burial of organic carbon. This will provide a possibility of interpreting not only the changes in the global carbon cycle throughout the geological time, but also that in atmospheric p CO 2

  16. A Comparative Study on Magnetostructural Properties of Barium Hexaferrite Powders Prepared by Polyethylene Glycol

    Directory of Open Access Journals (Sweden)

    Zehra Durmus

    2014-01-01

    Full Text Available Nanocrystalline particles of barium hexaferrite were synthesized by a sol-gel combustion route using nitrate-citrate gels prepared from metal nitrates and citric acid solutions with Fe/Ba molar ratio 12. The present paper aims to study the effect of addition of polyethylene glycol (PEG solutions with different molecular weights (MW: 400, 2000, and 10.000 g/mol on magnetostructural properties of barium hexaferrite. The formation of the barium hexaferrite was inspected using X-ray diffraction (XRD analysis, Fourier transform infrared (FT-IR analysis, thermogravimetric (TGA analysis, scanning electron microscopy (SEM analysis and vibrating sample magnetometer (VSM analysis for magnetic measurements.

  17. Barium promotes anchorage-independent growth and invasion of human HaCaT keratinocytes via activation of c-SRC kinase.

    Science.gov (United States)

    Thang, Nguyen Dinh; Yajima, Ichiro; Kumasaka, Mayuko Y; Ohnuma, Shoko; Yanagishita, Takeshi; Hayashi, Rumiko; Shekhar, Hossain U; Watanabe, Daisuke; Kato, Masashi

    2011-01-01

    Explosive increases in skin cancers have been reported in more than 36 million patients with arsenicosis caused by drinking arsenic-polluted well water. This study and previous studies showed high levels of barium as well as arsenic in the well water. However, there have been no reports showing a correlation between barium and cancer. In this study, we examined whether barium (BaCl(2)) may independently have cancer-related effects on human precancerous keratinocytes (HaCaT). Barium (5-50 µM) biologically promoted anchorage-independent growth and invasion of HaCaT cells in vitro. Barium (5 µM) biochemically enhanced activities of c-SRC, FAK, ERK and MT1-MMP molecules, which regulate anchorage-independent growth and/or invasion. A SRC kinase specific inhibitor, protein phosphatase 2 (PP2), blocked barium-mediated promotion of anchorage-independent growth and invasion with decreased c-SRC kinase activity. Barium (2.5-5 µM) also promoted anchorage-independent growth and invasion of fibroblasts (NIH3T3) and immortalized nontumorigenic melanocytes (melan-a), but not transformed cutaneous squamous cell carcinoma (HSC5 and A431) and malignant melanoma (Mel-ret) cells, with activation of c-SRC kinase. Taken together, our biological and biochemical findings newly suggest that the levels of barium shown in drinking well water independently has the cancer-promoting effects on precancerous keratinocytes, fibroblast and melanocytes in vitro.

  18. The role of the Ganges-Brahmaputra mixing zone in supplying barium and 226Ra to the Bay of Bengal

    International Nuclear Information System (INIS)

    Carroll, J.; Falkner, K.K.; Brown, E.T.; Moore, W.S.

    1993-01-01

    The Ganges-Brahmaputra river system is ranked fourth among world rivers as a source of freshwater to the oceans and is believed to supply more sediment to the ocean than any other; 1.5 x 10 12 kg/yr (Milliman and Meade, 1983). Barium and 226 Ra are typically enriched in waters where sediment-laden rivers enter the ocean. As such, the Ganges-Brahmaputra is likely to produce globally significant barium and 226 Ra fluxes to the ocean. Water samples for barium and 226 Ra were collected within four major channels of the Ganges-Brahmaputra mixing zone during a period of low sediment and freshwater discharge. The data suggest that in addition to suspended sediments supplied directly from rivers, river sediments deposited during high discharge in mangroves and on islands are desorbing barium and 226 Ra to seawater. The release of barium and 226 Ra from these sediment deposits is out-of-phase with the direct supply of sediments from the rivers. Estimates of the annual fluxes of barium and 226 Ra from the Ganges-Brahmaputra mixing zone were also derived. The fluxes of barium and 226 Ra are 5.3 x 10 8 mol barium/yr and 9.5 x 10 14 dpm radium/yr. The first silicate and phosphate mixing profiles for this system are reported. 29 refs., 6 figs., 3 tabs

  19. Indentation plasticity of barium titanate single crystals: Dislocation influence on ferroelectric domain walls

    Energy Technology Data Exchange (ETDEWEB)

    Liu, D. [Department of Mechanical Engineering, University of Houston, 4800 Calhoun Road, Houston, TX 77204 (United States)]. E-mail: duo.liu@mail.uh.edu; Chelf, M. [Department of Mechanical Engineering, University of Houston, 4800 Calhoun Road, Houston, TX 77204 (United States); White, K.W. [Department of Mechanical Engineering, University of Houston, 4800 Calhoun Road, Houston, TX 77204 (United States)

    2006-10-15

    The plastic behaviors of barium titanate (001) and (110) single crystals are studied with atomic force microscopy and piezoresponse force microscopy (PFM) following nanoindendation damage. Plastic deformation mechanisms of ferroelectric barium titanate single crystals are discussed with a focus on the interaction between PFM response and dislocation activities. Nanoindentation tests indicate that the theoretical strength is approached prior to the first pop-in event, consistent with the creation of dislocation nucleation sites required for the onset of plasticity. Surface topographic and piezoelectric analyses indicate that pile-ups around indents result from dislocation activities on the primary slip system, {l_brace}110{r_brace}{sub pc}<11-bar 0>{sub pc}. The more complex indentation-induced domain patterns observed on (110) barium titanate are also discussed.

  20. Clearance of barium from the oesophagus with diet cola and metoclopramide: A one stop approach to patients with dysphagia

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, J.; Farrow, R.; Hussaini, S.H.; Dalton, H.R

    2001-01-01

    AIM: To establish a 'one-stop' dysphagia service in which a consultation, barium swallow and endoscopy can all be performed in the same hospital visit. MATERIALS AND METHODS: In order to allow both barium swallow examination and endoscopy to be performed on the same day, a novel technique for clearing barium from the upper gastrointestinal tract was established. Following the barium swallow examination, patients were given diet cola and metoclopramide syrup. If appropriate, an upper gastrointestinal endoscopy was then performed shortly afterwards. The service was piloted for 6 months in which time 25 patients were investigated in this way. RESULTS: All patients were seen within 2 weeks of referral. The mean time between barium swallow and endoscopy was 3 h 38 min (range, 1 h 50 min to 5 h 20 min). In all 24 patients in whom an endoscopy was performed, barium had been satisfactorily cleared from the oesophagus and stomach. CONCLUSION: This technique allows both barium swallow and upper gastrointestinal endoscopy to be performed on the same day, providing a rapid, safe and accurate diagnosis with minimum patient inconvenience. Mitchell, J. (2001)

  1. Clearance of barium from the oesophagus with diet cola and metoclopramide: A one stop approach to patients with dysphagia

    International Nuclear Information System (INIS)

    Mitchell, J.; Farrow, R.; Hussaini, S.H.; Dalton, H.R.

    2001-01-01

    AIM: To establish a 'one-stop' dysphagia service in which a consultation, barium swallow and endoscopy can all be performed in the same hospital visit. MATERIALS AND METHODS: In order to allow both barium swallow examination and endoscopy to be performed on the same day, a novel technique for clearing barium from the upper gastrointestinal tract was established. Following the barium swallow examination, patients were given diet cola and metoclopramide syrup. If appropriate, an upper gastrointestinal endoscopy was then performed shortly afterwards. The service was piloted for 6 months in which time 25 patients were investigated in this way. RESULTS: All patients were seen within 2 weeks of referral. The mean time between barium swallow and endoscopy was 3 h 38 min (range, 1 h 50 min to 5 h 20 min). In all 24 patients in whom an endoscopy was performed, barium had been satisfactorily cleared from the oesophagus and stomach. CONCLUSION: This technique allows both barium swallow and upper gastrointestinal endoscopy to be performed on the same day, providing a rapid, safe and accurate diagnosis with minimum patient inconvenience. Mitchell, J. (2001)

  2. Inorganic markers, carbonaceous components and stable carbon isotope from biomass burning aerosols in northeast China

    Science.gov (United States)

    Cao, F.; Zhang, Y.; Kawamura, K.

    2015-12-01

    To better characterize the sources of fine particulate matter (i.e. PM2.5) in Sanjiang Plain, Northeast China, aerosol chemical composition such total carbon (TC), organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and inorganic ions were studied as well as stable carbon isotopic composition (δ13C) of TC. Intensively open biomass burning episodes were identified from late September to early October by satellite fire and aerosol optical depth maps. During the biomass burning episodes, concentrations of PM2.5, OC, EC, and WSOC increased by a factor of 4-12 compared to non-biomass-burning periods. Non-sea-salt potassium is strongly correlated with PM2.5, OC, EC and WSOC, suggesting an important contribution of biomass burning emission. The enrichment in both the non-sea-salt potassium and chlorine is significantly larger than other inorganic species, indicating that biomass burning aerosols in Sanjiang Plain is mostly fresh and less aged. In addition, WSOC to OC ratio is relatively lower compared to that reported in biomass burning aerosols in tropical regions, supporting that biomass burning aerosols in Sanjiang Plain is mostly primary and secondary organic aerosols is not significant. A lower average δ13C value (-26.2‰) is found for the biomass-burning aerosols, suggesting a dominant contribution from combustion of C3 plants in the studied region.

  3. 75 FR 33824 - Barium Chloride From China

    Science.gov (United States)

    2010-06-15

    ... China Determination On the basis of the record\\1\\ developed in the subject five-year review, the United... China would be likely to lead to continuation or recurrence of material injury to an industry in the... contained in USITC Publication 4157 (June 2010), entitled Barium Chloride from China: Investigation No. 731...

  4. Thermal decomposition of barium valerate in argon

    DEFF Research Database (Denmark)

    Torres, P.; Norby, Poul; Grivel, Jean-Claude

    2015-01-01

    The thermal decomposition of barium valerate (Ba(C4H9CO2)(2)/Ba-pentanoate) was studied in argon by means of thermogravimetry, differential thermal analysis, IR-spectroscopy, X-ray diffraction and hot-stage optical microscopy. Melting takes place in two different steps, at 200 degrees C and 280...

  5. Carbon-13 conundrums: limitations and cautions in the use of stable isotope analysis in stream ecotonal research

    International Nuclear Information System (INIS)

    France, R.L.

    1996-01-01

    A secondary analysis of literature was compiled and performed on the δ 13 C values for allochthonous litter, attached algae and consumers in stream ecosystems, finding that 'existing data conflict as to the capability of stable isotope analysis (SIA) for distinguishing carbon pathways'. The paper is in defence of the work previously performed and suggests caution when using stream SIA research. 48 refs

  6. Extended phase homogeneity and electrical properties of barium calcium titanate prepared by the wet chemical methods

    International Nuclear Information System (INIS)

    Jayanthi, S.; Kutty, T.R.N.

    2004-01-01

    Ca-substituted BaTiO 3 with extended homogeneity range upto ∼50 mol% CaTiO 3 have been prepared by three different chemical routes namely carbonate-oxalate (COBCT), gel-carbonate (GCBCT), and gel-to-crystallite conversion (GHBCT) followed by heat treatment above 1150 deg. C. X-ray powder diffraction (XRD) data show continuous decrease in the tetragonal unit cell parameters as well as c 0 /a 0 ratio with CaTiO 3 content, which are in accordance with the substitution of smaller sized Ca 2+ ions at the barium sites. The microstructure as well as the dielectric properties are greatly influenced by the cationic ratio, α=(Ba+Ca)/Ti. The grain size decreases with CaTiO 3 content for the stoichiometric samples (α=1), whereas ultrafine microstructure is observed in the case of off-stoichiometric samples (α>1) for the whole compositional range of CaTiO 3 concentrations. Sharper ε r -T characteristics at lower calcium content and broader ε r -T with decreased ε max , in the higher calcium range are observed in the case of α=1. Whereas nanometer grained ceramics exhibiting diffuse ε r -T characteristics are obtained in the case of α>1. The positive temperature coefficient of resistivity (PTCR) is realized for barium calcium titanate ceramics having 0.3 at.% Sb as the donor dopant for higher CaTiO 3 (typically 30 mol%) containing samples (α=1), indicating that Ca 2+ ions do not behave as acceptors if they were to substitute at the Ti 4+ sites. Whereas the off-stoichiometric (α>1) ceramics retained high resistivity, indicative of the Ti-site occupancy for Ca 2+ in fine grain ceramics

  7. Chemical analysis of carbonates and carbonate rocks by atomic absorption analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tardon, S

    1981-01-01

    Evaluates methods of determining chemical composition of rocks surrounding black coal seams. Carbonate rock samples were collected in the Ostrava-Karvina coal mines. Sampling methods are described. Determination of the following elements and compounds in carbonate rocks is discussed: calcium, magnesium, iron, manganese, barium, silicon, aluminium, titanium, sodium, potassium, sulfur trioxide, phosphorus pentoxide, water and carbon dioxide. Proportion of compounds insoluble in water in the investigated rocks is also determined. Most of the elements are determined by means of atomic absorption analysis. Phosphorus is also determined by atomic absorption analysis. Other compounds are determined gravimetrically. The described procedure permits weight of a rock sample to be reduced to 0.5 g without reducing analysis accuracy. The results of determining carbonate rock components by X-ray analysis and by chemical analysis are compared. Equipment used for atomic absorption analysis is characterized (the 503 Perkin-Elmer and the CF-4 Optica-Milano spectrophotometers). The analyzed method for determining carbonate rock permits more accurate classification of rocks surrounding coal seams and rock impurities in run-of-mine coal. (22 refs.) (In Czech)

  8. [Comparison of iodinated and barium-containing contrast media of different viscosity in the detection of pharyngeal perforation].

    Science.gov (United States)

    Keberle, M; Wittenberg, G; Trusen, A; Baumgartner, W; Hahn, D

    2001-08-01

    In contrast to esophageal perforations, the more radiopaque barium-suspensions are not as important as iodinated aqueous contrast agents for the detection of pharyngeal perforations. This study was performed to find out whether the highly different viscosities (of iodinated and barium-containing contrast agents with comparable radiopacities) are a reason for this. Viscosity, subjective difference in contrast, and CT-density of an iodinated aqueous (Telebrix) and a 50 wt/vol% barium-containing contrast agent (Micropaque) were determined. Moreover, to exclude postoperative perforation, 104 patients were prospectively examined by pharyngography using both contrast media. Pharyngographies of patients with perforation were later compared by two independent readers. All patients with perforation were followed up clinically to exclude complications due to barium administration. In-vitro comparison showed comparable radiopacity but the 50 wt/vol% barium-suspension was much more viscous than the iodinated contrast agent. During pharyngography, totally, 14 perforations were clearly delineated with the iodinated aqueous contrast agent. However, two of them were not detected with the barium-suspension. All the other perforations presented equally. Given a sufficient radiopacity, a low viscosity appears to be essential for a contrast agent to detect especially pharyngeal perforations. Thus, we recommend the sole use of an iodinated contrast agent (at suspicion of aspiration as isoosmolar variant) for this purpose.

  9. In vitro experiments for the development of a high density (HD) barium sulfate contrast medium

    International Nuclear Information System (INIS)

    Klein, J.

    1986-01-01

    In vitro experiments with the high-density (HD) barium meal Falibaryt HD are described. Several charges of BaSO 4 were tested together with certain additives influencing dispersion, stability of the suspension, flowability, surface tension etc. Particle size spectra were measured by the manufacturer, VEB Fahlberg-List. With a simple PVC test plate containing several grooves simulating small details (areae gastricae) the diagnostic capabilities of the HD contrast medium were evaluated in an in vitro test. The developed barium meal Falibaryt HD is in its physical and chemical parameters comparable with Prontobario-HD, one of the best HD barium meals. (author)

  10. Fabrication of yttrium-doped barium zirconate thin films with sub-micrometer thickness by a sol–gel spin coating method

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Hanlin; Su, Pei-Chen, E-mail: peichensu@ntu.edu.sg

    2015-06-01

    A modified sol–gel process was developed for the fabrication of sub-micrometer scale yttrium-doped barium zirconate (BZY) thin film at much lower processing temperatures. The film was fabricated by direct spin-coating of the sol on a Si{sub 3}N{sub 4} passivated Si substrate, followed by low temperature thermal annealing at 1000 °C, and single BZY phase without barium carbonate residue was obtained. A 200 nm-thick thin film without obvious through-film cracks was fabricated with optimized process parameters of sol concentration and heating rate. The stoichiometry of the BZY thin film was well-controlled and no Ba evaporation was observed due to the low processing temperature. The combination of sol–gel and spin coating method can be a promising alternative to vacuum-based thin film deposition techniques for the fabrication of sub-micrometer scale BZY thin film. - Highlights: • A sol–gel spin coating method was developed for the fabrication of BZY thin films. • The processing temperature was much lower compared to powder-based sintering. • Sub-micrometer scale BZY thin film with well-controlled stoichiometry was obtained.

  11. CuO and Ag2O effect on electrical properties of barium vanadate glasses

    International Nuclear Information System (INIS)

    Bogomolova, L.D.; Glasova, M.N.; Kalygina, V.M.; Spasibkina, S.N.; Khorikov, A.A.

    1987-01-01

    Effect of CuO on barium vanadate glass (BVG) conductivity on direct and alternating currents in the frequency range (10 2 -10 4 )Hz has been studied. Effect of Ag 2 O has been also studied for comparison, as Ag and Cu have idendical structure of external electron shells (d 10 , S 1 ). CuO introduction to binary barium vanadate glasses as a modificator results in the conductivity improvement on direct and alternating currents conditioned with reducing activation energy of small radius polaron jump, apparently, owing to exchange (ferromagnetic) interaction between V(IV) and Cu(II). Jump activation energy in barium vanadate glasses with Ag 2 O increases and conductivity drops due to the distance increase between vanadium atoms

  12. Barium zirconate-titanate/barium calcium-titanate ceramics via sol-gel process: novel high-energy-density capacitors

    International Nuclear Information System (INIS)

    Puli, Venkata Sreenivas; Kumar, Ashok; Scott, J F; Katiyar, Ram S; Chrisey, Douglas B; Tomozawa, M

    2011-01-01

    Lead-free barium zirconate-titanate/barium calcium-titanate, [(BaZr 0.2 Ti 0.80 )O 3 ] 1-x -[(Ba 0.70 Ca 0.30 )TiO 3 ] x (x = 0.10, 0.15, 0.20) (BZT-BCT) ceramics with high dielectric constant, low dielectric loss and moderate electric breakdown field were prepared by the sol-gel synthesis technique. X-ray diffraction patterns revealed tetragonal crystal structure and this was further confirmed by Raman spectra. Well-behaved ferroelectric hysteresis loops and moderate polarizations (spontaneous polarization, P s ∼ 3-6 μC cm -2 ) were obtained in these BZT-BCT ceramics. Frequency-dependent dielectric spectra confirmed that ferroelectric diffuse phase transition (DPT) exists near room temperature. Scanning electron microscope images revealed monolithic grain growth in samples sintered at 1280 deg. C. 1000/ε versus (T) plots revealed ferroelectric DPT behaviour with estimated γ values of ∼1.52, 1.51 and 1.88, respectively, for the studied BZT-BCT compositions. All three compositions showed packing-limited breakdown fields of ∼47-73 kV cm -1 with an energy density of 0.05-0.6 J cm -3 for thick ceramics (>1 mm). Therefore these compositions might be useful in Y5V-type capacitor applications.

  13. Stabilization of recent soil carbon in the humid tropics following land use changes: evidence from aggregate fractionation and stable isotope analyses

    OpenAIRE

    Paul, Sonja; Flessa, Heiner; Veldkamp, Edzo; López-Ulloa, Magdalena

    2008-01-01

    Keywords: Carbon sequestration - Ecuador - Mean residence time - Pasture - Secondary forest - Soil type - Texture - Water-stable aggregates Quantitative knowledge of stabilization- and decomposition processes is necessary to understand, assess and predict effects of land use changes on storage and stability of soil organic carbon (soil C) in the tropics. Although it is well documented that different soil types have different soil C stocks, it is presently unknown how different soil types a...

  14. Synthesis and characterization of M-type barium hexferrite by ultrasonic inter-dispersion of chemical precipitate

    International Nuclear Information System (INIS)

    Garcia Junior, E.S.; Gomes Junior, G.G.; Ogasawara, T.

    2010-01-01

    This work is concerned with the study the synthesis and characterization of M-type barium hexaferrite powder by chemical precipitation type and ultrasonic interdispersion of precursor materials Fe(OH) 3 and Ba(OH) 2 ,separately and ultrasonic inter-dispersion, followed by drying and calcining. In order to guide the experimental work was carried out a preliminary thermodynamic analysis of the system Ba-Fe-H 2 O at 25 deg C. The study shows that the phase formation of M-type barium hexaferrite is obtained at a calcination at 1000 deg C, characterized by X-ray diffraction, the grain growth of the final product of synthesis depending on the calcination temperature is visible by SEM. The synthesis method developed in this research is an option to achieve the results that would be obtained if the co-precipitation of ferric and barium hydroxide was thermodynamically possible, where you can get crystallization of barium hexaferrite in a calcination at 1000 deg C. (author)

  15. Pressure-assisted sintering of high purity barium titanate

    NARCIS (Netherlands)

    van den Cruijsem, S.; Varst, van der P.G.T.; With, de G.; Bortzmeyer, D.; Boussuge, M.; Chartier, Th.; Hausonne, J.M.; Mocellin, A.; Rousset, A.; Thevenot, F.

    1997-01-01

    The dielectric behaviour of High Purity Barium titanate (HPB) ceramics is strongly dependent on the grain size and porosity. For applications, control of grain size and porosity is required. Pressure-assisted sintering techniques at relatively low temperatures meet these requirements. In this study,

  16. Water-soluble contrast media compared with barium in enteric follow-through

    International Nuclear Information System (INIS)

    Laerum, F.; Stordahl, A.; Aase, S.

    1988-01-01

    The local effects and radiographic efficacy of 4 water-soluble contrast media, barium and saline were evaluated in 86 anaesthetized rats with the distal ileum ligated. The rats were observed for 8 hours after instillation of 3 ml of the test substance via orogastric tube. Radiographs were taken after 1, 4 and 8 hours of observation. After 8 hours the intestines were weighed and biopsied for light microscopy, and blood and urine were sampled for testing. Sodium diatrizoate caused increased fluid influx to the bowel lumen and, like barium, provided poorer radiographic images as compared with iohexol, ioxaglate or iodixanol. Barium showed slower progression through the small bowel than the other agents, while sodium diatrizoate was the most rapidly progressing contrast medium and caused the greatest distension. Correlation to osmolality was obvious. No significant morphologic effects on the small bowel mucosa were seen in any of the groups. Low-osmolar, water-soluble contrast media may have prospects for clinical use in patients with suspected small bowel obstruction. (orig.)

  17. Early colon cancer : findings on double contrast barium enema

    International Nuclear Information System (INIS)

    Kim, Seung Kwon; Lim, Jae Hoon; Lee, Soon Jin; Lim, Hyo Keun

    1998-01-01

    The purpose of this study is to describe the radiologic findings of early colon cancer on double-contrast barium enema. We retrospectively reviewed the double-contrast barium enemas of eight patients (M:F = 6:2; mean age : 67 yrs; range : 48-77 yrs) who were pathologically proven to be early colon cancer. The location, size and gross morphology of lesions was evaluated using double-contrast barium enema, while depth of invasion, degree of differentiation, precancerous lesions and lymph node metastasis were evaluated histopathologically. Early colon cancer was found in the rectum (n=4), sigmoid colon (n=3) and ascending colon (n=1). The size of mass ranged from 2.3 ∼ 8.3 (mean, 4.6) cm. And the polypoid type was most common (n=7); this was subdivided into sessile (Is, n=5), semipedunculated (Isp, n=1) and pedunculated type (Ip, n=1). Another mass was a sessile polypoid combined with a flat depressed lesion. In eight cases, four cancers were confined to the mucosa, while the remaining four had infiltrated the submucosa. Most cancers arose from villous and villotubular adenoma. All cases were well-differentiated adenocarcinoma and no metastasis to lymph nodes had occurred. In early colon cancer, lesions were mainly polypoid and large. Most arose from villous and villotubular adenoma. (author). 19 refs., 1 tab., 3 figs

  18. Calorimetric study of interaction of barium hydroxide with diluted solutions of hydrofluoric acid

    International Nuclear Information System (INIS)

    Kurbanov, A.R.; Sharipov, D.Sh.

    1993-01-01

    Present article is devoted to calorimetric study of interaction of barium hydroxide with diluted solutions of hydrofluoric acid. The calorimetric study of interaction of barium hydroxide with diluted solutions of hydrofluoric acid was carried out in order to determine the thermal effects of reactions. The results of interaction of Ba(OH) 4 ·8H 2 O with 5, 10, and 20% solution of hydrofluoric acid were considered.

  19. Stable carbon isotope depth profiles and soil organic carbon dynamics in the lower Mississippi Basin

    Science.gov (United States)

    Wynn, J.G.; Harden, J.W.; Fries, T.L.

    2006-01-01

    Analysis of depth trends of 13C abundance in soil organic matter and of 13C abundance from soil-respired CO2 provides useful indications of the dynamics of the terrestrial carbon cycle and of paleoecological change. We measured depth trends of 13C abundance from cropland and control pairs of soils in the lower Mississippi Basin, as well as the 13C abundance of soil-respired CO2 produced during approximately 1-year soil incubation, to determine the role of several candidate processes on the 13C depth profile of soil organic matter. Depth profiles of 13C from uncultivated control soils show a strong relationship between the natural logarithm of soil organic carbon concentration and its isotopic composition, consistent with a model Rayleigh distillation of 13C in decomposing soil due to kinetic fractionation during decomposition. Laboratory incubations showed that initially respired CO 2 had a relatively constant 13C content, despite large differences in the 13C content of bulk soil organic matter. Initially respired CO2 was consistently 13C-depleted with respect to bulk soil and became increasingly 13C-depleted during 1-year, consistent with the hypothesis of accumulation of 13C in the products of microbial decomposition, but showing increasing decomposition of 13C-depleted stable organic components during decomposition without input of fresh biomass. We use the difference between 13C / 12C ratios (calculated as ??-values) between respired CO 2 and bulk soil organic carbon as an index of the degree of decomposition of soil, showing trends which are consistent with trends of 14C activity, and with results of a two-pooled kinetic decomposition rate model describing CO2 production data recorded during 1 year of incubation. We also observed inconsistencies with the Rayleigh distillation model in paired cropland soils and reasons for these inconsistencies are discussed. ?? 2005 Elsevier B.V. All rights reserved.

  20. Barium-induced skeletal muscle paralysis in the rat, and its relationship to human familial periodic paralysis

    Science.gov (United States)

    Schott, G. D.; McArdle, B.

    1974-01-01

    An in vivo study of skeletal muscle paralysis induced by intravenous barium chloride has been made in curarized and non-curarized rats. The influence of potassium and calcium chlorides, propranolol, ouabain, and prior adrenalectomy on the paralysis has also been studied. Paralysis is found to be due to a direct effect on skeletal muscle, and to correlate well with the development of hypokalaemia. Possible mechanisms of action of barium are discussed, and attention is drawn to the similarity between barium poisoning and hypokalaemic familial periodic paralysis. PMID:4813426

  1. Freezing and fractionation: effects of preservation on carbon and nitrogen stable isotope ratios of some limnetic organisms.

    Science.gov (United States)

    Wolf, J Marshall; Johnson, Brett; Silver, Douglas; Pate, William; Christianson, Kyle

    2016-03-15

    Stable isotopes of carbon and nitrogen have become important natural tracers for studying food-web structure and function. Considerable research has demonstrated that chemical preservatives and fixatives shift the isotopic ratios of aquatic organisms. Much less is known about the effects of freezing as a preservation method although this technique is commonly used. We conducted a controlled experiment to test the effects of freezing (-10 °C) and flash freezing (–79 °C) on the carbon and nitrogen isotope ratios of zooplankton (Cladocera), Mysis diluviana and Rainbow Trout (Oncorhynchus mykiss). Subsamples (~0.5 mg) of dried material were analyzed for percentage carbon, percentage nitrogen, and the relative abundance of stable carbon and nitrogen isotopes (δ13C and δ15N values) using a Carlo Erba NC2500 elemental analyzer interfaced to a ThermoFinnigan MAT Delta Plus isotope ratio mass spectrometer. The effects of freezing were taxon-dependent. Freezing had no effect on the isotopic or elemental values of Rainbow Trout muscle. Effects on the δ13C and δ15N values of zooplankton and Mysis were statistically significant but small relative to typical values of trophic fractionation. The treatment-control offsets had larger absolute values for Mysis (δ13C: ≤0.76 ± 0.41‰, δ15N: ≤0.37 ± 0.16‰) than for zooplankton (δ13C: ≤0.12 ± 0.06‰, δ15N: ≤0.30 ± 0.27‰). The effects of freezing were more variable for the δ13C values of Mysis, and more variable for the δ15N values of zooplankton. Generally, both freezing methods reduced the carbon content of zooplankton and Mysis, but freezing had a negative effect on the %N of zooplankton and a positive effect on the %N of Mysis. The species-dependencies and variability of freezing effects on aquatic organisms suggest that more research is needed to understand the mechanisms responsible for freezing-related fractionation before standardized protocols for freezing as a preservation method can be adopted.

  2. Stable isotope composition of atmospheric carbon monoxide. A modelling study

    International Nuclear Information System (INIS)

    Gromov, Sergey S.

    2014-01-01

    This study aims at an improved understanding of the stable carbon and oxygen isotope composition of the carbon monoxide (CO) in the global atmosphere by means of numerical simulations. At first, a new kinetic chemistry tagging technique for the most complete parameterisation of isotope effects has been introduced into the Modular Earth Submodel System (MESSy) framework. Incorporated into the ECHAM/MESSy Atmospheric Chemistry (EMAC) general circulation model, an explicit treatment of the isotope effects on the global scale is now possible. The expanded model system has been applied to simulate the chemical system containing up to five isotopologues of all carbon- and oxygen-bearing species, which ultimately determine the δ 13 C, δ 18 O and Δ 17 O isotopic signatures of atmospheric CO. As model input, a new stable isotope-inclusive emission inventory for the relevant trace gases has been compiled. The uncertainties of the emission estimates and of the resulting simulated mixing and isotope ratios have been analysed. The simulated CO mixing and stable isotope ratios have been compared to in-situ measurements from ground-based observatories and from the civil-aircraft-mounted CARIBIC-1 measurement platform. The systematically underestimated 13 CO/ 12 CO ratios of earlier, simplified modelling studies can now be partly explained. The EMAC simulations do not support the inferences of those studies, which suggest for CO a reduced input of the highly depleted in 13 C methane oxidation source. In particular, a high average yield of 0.94 CO per reacted methane (CH 4 ) molecule is simulated in the troposphere, to a large extent due to the competition between the deposition and convective transport processes affecting the CH 4 to CO reaction chain intermediates. None of the other factors, assumed or disregarded in previous studies, however hypothesised to have the potential in enriching tropospheric CO in 13 C, were found significant when explicitly simulated. The

  3. Three barium diphosphonates with 3-D structures

    Science.gov (United States)

    Tuikka, Matti; Haukka, Matti; Ahlgrén, Markku

    2007-06-01

    The gel crystallization method was exploited in this work in order to study the 3-D solid state structures of barium diphosphonates. This technique proved to be an effective tool for the growth of single crystals of diphosphonates for structure analysis. By using this approach, three barium diphosphonates, Ba[HO 3P(CH 2) 2PO 3H] ( 1), Ba 2[O 3P(CH 2) 3PO 3]·3H 2O ( 2) and Ba[HO 3P(CH 2) 4PO 3H] ( 3), with different three dimensional structures, were synthesized and characterized. The structures of compounds 1 and 2 were determined by single crystal X-ray diffraction and the structure of 3 by the powder diffraction method. In the structure of 1, the diphosphonate ligand is completely surrounded by the Ba atoms, which is an unusual arrangement in a diphosphonate system. The structures of 2 and 3 are more conventional. They are organized in typical pillared layers in which the separation of the layers can be adjusted by varying the length of the hydrocarbon chain.

  4. The Novel Formation of Barium Titanate Nanodendrites

    Directory of Open Access Journals (Sweden)

    Chien-Jung Huang

    2014-01-01

    Full Text Available The barium titanate (BaTiO3 nanoparticles with novel dendrite-like structures have been successfully fabricated via a simple coprecipitation method, the so-called BaTiO3 nanodendrites (BTNDs. This method was remarkable, fast, simple, and scalable. The growth solution is prepared by barium chloride (BaCl2, titanium tetrachloride (TiCl4, and oxalic acid. The shape and size of BaTiO3 depend on the amount of added BaCl2 solvent. To investigate the influence of amount of BaCl2 on BTNDs, the amount of BaCl2 was varied in the range from 3 to 6 mL. The role of BaCl2 is found to have remarkable influence on the morphology, crystallite size, and formation of dendrite-like structures. The thickness and length of the central stem of BTND were ~300 nm and ~20 μm, respectively. The branchings were found to occur at irregular intervals along the main stem. Besides, the formation mechanism of BTND is proposed and discussed.

  5. Stable isotope (C, O) and monovalent cation fractionation upon synthesis of carbonate-bearing hydroxyl apatite (CHAP) via calcite transformation

    Science.gov (United States)

    Böttcher, Michael E.; Schmiedinger, Iris; Wacker, Ulrike; Conrad, Anika C.; Grathoff, Georg; Schmidt, Burkhard; Bahlo, Rainer; Gehlken, Peer-L.; Fiebig, Jens

    2016-04-01

    Carbonate-bearing hydroxyl-apatite (CHAP) is of fundamental and applied interest to the (bio)geochemical, paleontological, medical and material science communities, since it forms the basic mineral phase in human and animal teeth and bones. In addition, it is found in non-biogenic phosphate deposits. The stable isotope and foreign element composition of biogenic CHAP is widely used to estimate the formation conditions. This requires careful experimental calibration under well-defined boundary conditions. Within the DFG project EXCALIBOR, synthesis of carbonate-bearing hydroxyapatite was conducted via the transformation of synthetic calcite powder in aqueous solution as a function of time, pH, and temperature using batch-type experiments. The aqueous solution was analyzed for the carbon isotope composition of dissolved inorganic carbonate (gas irmMS), the oxygen isotope composition of water (LCRDS), and the cationic composition. The solid was characterized by powder X-ray diffraction, micro Raman and FTIR spectroscopy, SEM-EDX, elemental analysis (EA, ICP-OES) and gas irmMS. Temperature was found to significantly impact the transformation rate of calcite to CHAP. Upon complete transformation, CHAP was found to contain up to 5% dwt carbonate, depending on the solution composition (e.g., pH), both incorporated on the A and B type position of the crystal lattice. The oxygen isotope fractionation between water and CHAP decreased with increasing temperature with a tentative slope shallower than those reported in the literature for apatite, calcite or aragonite. In addition, the presence of dissolved NH4+, K+ or Na+ in aqueous solution led to partial incorporation into the CHAP lattice. How these distortions of the crystal lattice may impact stable isotope discrimination is subject of future investigations.

  6. Clinical efficacy of a new barium sulfate for abdominal CT

    International Nuclear Information System (INIS)

    Yamada, Tatuya; Kohno, Mitio; Uematsu, Sadao; Nisitani, Hiromu; Tanaka, Takao.

    1988-01-01

    Computed Tomography of the abdomen requires that the intestines are filled with contrast medium so that the gut is not misinterpreted as a pathologic process. Besides, normal structures may be difficult to delimit in patients with scanty intra-abdominal fat. In Japan, up to date, only a single contrast medium has been available for this purpose, Gastrografin and thus identical with the intravasculaly used Urografin or Angiografin. A new Barium Sulfate suspention (Fusimi Seiyaku, Kagawa) for computed tomographic use has been dilute solution (4.77 %) and with suspending agents that prevent a rapid sedimentation of the Barium Sulfate. The aim of this investigation was to compare Gastrografin with a new barium regarding patients tolerance, side effects and diagnostic information. The investigation comprised 146 patients who were reffered for abdominal CT and was carried out by 5 facilities; National Cancer Center, Kobe University, Chiba University, Kyushu University and Juntendo University. Diagnostic information was judged with respect to the filling of the stomach and intestines, the presence of imaging artifacts and finally clinical estimation. Patients tolerance was investigated as regards taste and side effects. Good filling of the stomach and intestines was obtained in this investigation. However, imaging artifacts occured in only a few cases. The imaging artifacts appeared almost exclusively to arise in the boundary layer between the bowel gas and contrast medium, and were most common in the stomach. However, the contrasting effect of this medium did not in itself appear to cause any imaging artifacts. Fushimi's new barium seems to be preffered because of its lesser tendency to arise artifacts and better tendency to make good filling of the stomach and intestines. Moreover, this investigation did not have any side effects. (J.P.N.)

  7. Facile synthesis of carbon/MoO 3 nanocomposites as stable battery anodes

    KAUST Repository

    Ding, Jiang

    2017-03-09

    Pristine MoO3 is a potential anode material for lithium-ion batteries (LIBs), due to its high specific capacity (1117 mA h g−1); it suffers, however, from poor cyclability, resulting from a low conductivity and large volume changes during lithiation/delithiation process. Here we adopt a facile two-step method in which pristine bulk MoO3 is first converted into MoO3 nanorods (MoO3 NR) through mechanical grinding, to buffer the continuous volume changes, and then coated with amorphous carbon through simple stirring and heating, to provide high electronic and ionic conductivities. Electrochemical tests reveal that the carbon-coated MoO3 nanorods (C-MoO3 NRs) exhibit outstanding specific capacity (856 mA h g−1 after 110 cycles at a current density of 0.1 C); remarkable cycle life, among the best reported for carbon-based MoO3 nanostructures (485 mA h g−1 after 300 cycles at 0.5 C and 373 mA h g−1 after 400 cycles at 0.75 C); and greatly improved capacity retention (up to 90.4% after various C-rates) compared to bulk MoO3. We confirm the versatility of the C-MoO3 NR anodes by preparing flexible batteries that display stable performance, even in bent state. This simple approach toward C-MoO3 NR anodes proceeds without rigorous chemical synthesis or extremely high temperatures, making it a scalable solution to prepare high-capacity anodes for next-generation LIBs.

  8. Influence of Magnetron Effect on Barium Hexaferrite Thin Layers

    International Nuclear Information System (INIS)

    Hassane, H.; Chatelon, J.P.; Rousseau, J.J; Siblini, A.; Kriga, A.

    2011-01-01

    In this paper, we study the effects of a magnet, located in the cathode, on barium hexaferrite thin films deposited by RF magnetron sputtering technique. During the process, these effects can modify thickness, roughness and stress of coatings. The characteristics of the deposited layers depend on the substrate position that is located opposite of magnetron cathode. In the m agnetron area , one can observe that the high stress can produce cracks or detachment of layers and the increasing of both depositing rate and surface roughness. After sputtering elaboration, barium hexaferrite films are in a compressive stress mode. But, after the post-deposition heat treatment these films are in a tensile stress mode. To improve the quality of BaM films, the subsrtate has to be set outside the magnetron area. (author)

  9. SAD phasing with in-house cu Ka radiation using barium as anomalous scatterer.

    Science.gov (United States)

    Dhanasekaran, V; Velmurugan, D

    2011-12-01

    Phasing of lysozyme crystals using co-crystallized barium ions was performed using single-wavelength anomalous diffraction (SAD) method using Cu Ka radiation with in-house source of data collection. As the ion binding sites vary with respect to the pH of the buffer during crystallization, the highly isomorphic forms of lysozyme crystals grown at acidic and alkaline pH were used for the study. Intrinsic sulphur anomalous signal was also utilized with anomalous signal from lower occupancy ions for phasing. The study showed that to solve the structure by SAD technique, 2.8-fold data redundancy was sufficient when barium was used as an anomalous marker in the in-house copper X-ray radiation source for data collection. Therefore, co-crystallization of proteins with barium containing salt can be a powerful tool for structure determination using lab source.

  10. Production of autoionizing di-excited states of barium with high angular momentum

    International Nuclear Information System (INIS)

    Roussel, F.; Breger, P.; Gounand, F.; Spiess, G.

    1988-01-01

    Autoionizing di-excited states Ba(6p 1/2 27l) with 7 ≤l≤26, have been experimentally detected. They have been produced by a method combining excitation by two lasers and l-mixing collisions between barium and xenon. Results show that a long delay between the two laser excitation steps is favourable to the production of these states. The method has proved to be very efficient (measured cross-section: σ = 3.1 . 10 -13 cm 2 ) for populating high-angular-momentum autoionizing states of barium

  11. Formation and filtration characteristics of solids generated in a high level liquid waste treatment process. Solids formation behavior from simulated high level liquid waste

    International Nuclear Information System (INIS)

    Kondo, Y.; Kubota, M.

    1997-01-01

    The solids formation behavior in a simulated high level liquid waste (HLLW) was experimentally examined, when the simulated HLLW was treated in the ordinary way of actual HLLW treatment process. Solids formation conditions and mechanism were closely discussed. The solids formation during a concentration step can be explained by considering the formation of zirconium phosphate, phosphomolybdic acid and precipitation of strontium and barium nitrates and their solubilities. For the solids formation during the denitration step, at least four courses were observed; formation of an undissolved material by a chemical reaction with each other of solute elements (zirconium, molybdenum, tellurium) precipitation by reduction (platinum group metals) formation of hydroxide or carbonate compounds (chromium, neodymium, iron, nickel, strontium, barium) and a physical adsorption to stable solid such as zirconium molybdate (nickel, strontium, barium). (author)

  12. Effects of Water Vapor on the Data Quality of the Stable Oxygen Isotopic Ratio of Atmospheric Carbon Dioxide

    Science.gov (United States)

    Evans, C. U.; White, J. W.; Vaughn, B.; Tans, P. P.; Pardo, L.

    2007-12-01

    The stable oxygen isotopic ratio of carbon dioxide can potentially track fundamental indicators of environmental change such as the balance between photosynthesis and respiration on regional to global scales. The Stable Isotope Laboratory (SIL) at the Institute of Arctic and Alpine Research (INSTAAR), University of Colorado at Boulder, has measured the stable isotopes of atmospheric carbon dioxide from more than 60 NOAA/Earth System Research Laboratory (ESRL) air flask-sampling sites since the early 1990s. If air is sampled without drying, oxygen can exchange between carbon dioxide and water in the flasks, entirely masking the desired signal. An attempt to investigate how water vapor is affecting the δ18O signal is accomplished by comparing the SIL measurements with specific humidity, calculated from the National Climatic Data Center (NCDC) global integrated surface hourly temperature and dew point database, at the time of sampling. Analysis of sites where samples have been collected initially without drying, and subsequently with a drying kit, in conjunction with the humidity data, has led to several conclusions. Samples that initially appear isotopically unaltered, in that their δ18O values are within the expected range, are being subtly influenced by the water vapor in the air. At Bermuda and other tropical to semi-tropical sites, the 'wet' sampling values have a seasonal cycle that is strongly anti-correlated to the specific humidity, while the 'dry' values have a seasonal cycle that is shifted earlier than the specific humidity cycle by 1-2 months. The latter phasing is expected given the seasonal phasing between climate over the ocean and land, while the former is consistent with a small, but measurable isotope exchange in the flasks. In addition, we note that there is a strong (r > 0.96) correlation between the average specific humidity and the percent of rejected samples for 'wet' sampling. This presents an opportunity for determining a threshold of

  13. ORIGINAL ARTICLE ORIG ORIG Comparison of barium and ...

    African Journals Online (AJOL)

    SA JOURNAL OF RADIOLOGY • June 2007. ORIG. Abstract. Background. Simulation of patients with carcinoma of the oesophagus using radio-opaque contrast is a standard step in treatment planning prior to delivering radiation therapy. Various contrast mediums such as barium, gastrograffin and hexabrix have been used ...

  14. Spectrophotometry of carbon stars

    International Nuclear Information System (INIS)

    Gow, C.E.

    1975-01-01

    Observations of over one hundred carbon stars have been made with the Indiana rapid spectral scanner in the red and, when possible, in the visual and blue regions of the spectrum. Five distinct subtypes of carbon stars (Barium, CH, R, N, and hydrogen deficient) are represented in the list of observed stars, although the emphasis was placed on the N stars when the observations were made. The rapid scanner was operated in the continuous sweep mode with the exit slit set at twenty angstroms, however, seeing fluctuations and guiding errors smear the spectrum to an effective resolution of approximately thirty angstroms. Nightly observations of Hayes standard stars yielded corrections for atmospheric extinction and instrumental response. The reduction scheme rests on two assumptions, that thin clouds are gray absorbers and the wavelength dependence of the sky transparency does not change during the course of the night. Several stars have been observed in the blue region of the spectrum with the Indiana SIT vidicon spectrometer at two angstroms resolution. It is possible to derive a color temperature for the yellow--red spectral region by fitting a black-body curve through two chosen continuum points. Photometric indices were calculated relative to the blackbody curve to measure the C 2 Swan band strength, the shape of the CN red (6,1) band to provide a measure of the 12 C/ 13 C isotope ratio, and in the hot carbon stars (Barium, CH, and R stars) the strength of an unidentified feature centered at 400 angstroms. An extensive abundance grid of model atmospheres was calculated using a modified version of the computer code ATLAS

  15. Structural and optical study of tellurite-barium glasses

    Science.gov (United States)

    Grelowska, I.; Reben, M.; Burtan, B.; Sitarz, M.; Cisowski, J.; Yousef, El Sayed; Knapik, A.; Dudek, M.

    2016-12-01

    The goal of this work was to determine the effect of barium oxide on the structural, thermal and optical properties of the TeO2-BaO-Na2O (TBN) and TeO2-BaO-WO3 (TBW) glass systems. Raman spectra allow relating the glass structure and vibration properties (i.e. vibrational frequencies and Raman intensities) with the glass composition. Raman spectra show the presence of TeO4 and TeO3+1/TeO3 units that conform with the glass matrix. Differential thermal analysis DTA, XRD measurements have been considered in term of BaO addition. The spectral dependence of ellipsometric angles of the tellurite-barium glass has been studied. The optical measurements were conducted on Woollam M2000 spectroscopic ellipsometer in spectral range of 190-1700 nm. The reflectance and transmittance measurements have been done on spectrophotometer Perkin Elmer, Lambda 900 in the range of 200-2500 nm (UV-VIS-NIR). From the transmittance spectrum, the energy gap was determined.

  16. Stable optical soliton in the ring-cavity fiber system with carbon nanotube as saturable absorber

    Science.gov (United States)

    Li, Bang-Qing; Ma, Yu-Lan; Yang, Tie-Mei

    2018-01-01

    Main attention focuses on the theoretical study of the ring-cavity fiber laser system with carbon nanotubes (CNT) as saturable absorber (SA). The system is modelled as a non-standard Schrödinger equation with the coefficients blended real and imaginary numbers. New stable exact soliton solution is constructed by the bilinear transformation method for the system. The influences of the key parameters related to CNTs and SA on the optical pulse soliton are discussed in simulation. The soliton amplitude and phase can be tuned by choosing suitable parameters.

  17. Calculations of energy levels and lifetimes of low-lying states of barium and radium

    International Nuclear Information System (INIS)

    Dzuba, V. A.; Ginges, J. S. M.

    2006-01-01

    We use the configuration-interaction method and many-body perturbation theory to perform accurate calculations of energy levels, transition amplitudes, and lifetimes of low-lying states of barium and radium. Calculations for radium are needed for the planning of measurements of parity- and time-invariance-violating effects which are strongly enhanced in this atom. Calculations for barium are used to control the accuracy of the calculations

  18. petrography, compositional characteristics and stable isotope ...

    African Journals Online (AJOL)

    PROF EKWUEME

    Subsurface samples of the predominantly carbonate Ewekoro Formation, obtained from Ibese core hole within the Dahomey basin were used in this study. Investigations entail petrographic, elemental composition as well as stable isotopes (carbon and oxygen) geochemistry in order to deduce the different microfacies and ...

  19. Environmental consequences of the placement of radium-barium sludge in tailings areas

    International Nuclear Information System (INIS)

    Huck, P.M.; Brown, J.R.; Multimaki, G.; Murphy, K.L.

    1982-01-01

    A preliminary evaluation was made of the implications of placing radium-barium sludge in tailings areas. The study was restricted to a consideration of possible increases in the quantities of radionuclides escaping to the environment through either groundwater or surface water, considering the types of tailings treated and the effluent treatment systems currently operating in Canada. It was concluded that the placement of radium/barium sludge in tailings areas should not adversely affect the long-term stability of the radionuclides in the tailings or sludge, based on geochemical inorganic reactions

  20. Authenticity and traceability of vanilla flavors by analysis of stable isotopes of carbon and hydrogen.

    Science.gov (United States)

    Hansen, Anne-Mette Sølvbjerg; Fromberg, Arvid; Frandsen, Henrik Lauritz

    2014-10-22

    Authenticity and traceability of vanilla flavors were investigated using gas chromatography-isotope ratio mass spectrometry (GC-IRMS). Vanilla flavors produced by chemical synthesis (n = 2), fermentation (n = 1), and extracted from two different species of the vanilla orchid (n = 79) were analyzed. The authenticity of the flavor compound vanillin was evaluated on the basis of measurements of ratios of carbon stable isotopes (δ(13)C). It was found that results of δ(13)C for vanillin extracted from Vanilla planifolia and Vanilla tahitensis were significantly different (t test) and that it was possible to differentiate these two groups of natural vanillin from vanillin produced otherwise. Vanilla flavors were also analyzed for ratios of hydrogen stable isotopes (δ(2)H). A graphic representation of δ(13)C versus δ(2)H revealed that vanillin extracted from pods grown in adjacent geographic origins grouped together. Accordingly, values of δ(13)C and δ(2)H can be used for studies of authenticity and traceability of vanilla flavors.

  1. Stable carbon and nitrogen isotope ratios of sodium and potassium cyanide as a forensic signature.

    Science.gov (United States)

    Kreuzer, Helen W; Horita, Juske; Moran, James J; Tomkins, Bruce A; Janszen, Derek B; Carman, April

    2012-01-01

    Sodium and potassium cyanide are highly toxic, produced in large amounts by the chemical industry, and linked to numerous high-profile crimes. The U.S. Centers for Disease Control and Prevention has identified cyanide as one of the most probable agents to be used in a chemical terrorism event. We investigated whether stable C and N isotopic content of sodium and potassium cyanide could serve as a forensic signature for sample matching, using a collection of 65 cyanide samples. Upon analysis, a few of the cyanide samples displayed nonhomogeneous isotopic content associated with degradation to a carbonate salt and loss of hydrogen cyanide. Most samples had highly reproducible isotope content. Of the 65 cyanide samples, >95% could be properly matched based on C and N isotope ratios, with a false match rate <3%. These results suggest that stable C and N isotope ratios are a useful forensic signature for matching cyanide samples. © 2011 American Academy of Forensic Sciences.

  2. Double contrast with technique of Insufflated Barium Meal in the radiological study of the esophagus

    International Nuclear Information System (INIS)

    Gallina, F.; Piga, V.; Gallina, M.S.

    1985-01-01

    The results are reported of the esophagus double contrast examination with Insufflated Barium Meal technique as first part of the routine upper digestive system radiological examination. This technique gives good double contrast without those artifacts using effervescent powders and without modifying the normal radiological alimentary tract examination established way. The double contrast is administered by a special container with a built-in mouthpiece which allows the simultaneous ingestion of barium suspension and air. The esophageal mucosa can be examined as far as the distal tract where frequently the barium contrast stops using different techniques. Good results in 90% of patients have been obtained. The early detection of inflammatory and tumoral lesions has taken particular advantage in patients sometimes asymptomatic

  3. Double contrast with technique of Insufflated Barium Meal in the radiological study of the esophagus

    Energy Technology Data Exchange (ETDEWEB)

    Gallina, F; Piga, V; Gallina, M.S. and others

    1985-01-01

    The results are reported of the esophagus double contrast examination with Insufflated Barium Meal technique as first part of the routine upper digestive system radiological examination. This technique gives good double contrast without those artifacts using effervescent powders and without modifying the normal radiological alimentary tract examination established way. The double contrast is administered by a special container with a built-in mouthpiece which allows the simultaneous ingestion of barium suspension and air. The esophageal mucosa can be examined as far as the distal tract where frequently the barium contrast stops using different techniques. Good results in 90% of patients have been obtained. The early detection of inflammatory and tumoral lesions has taken particular advantage in patients sometimes asymptomatic.

  4. Barium zirconate-titanate/barium calcium-titanate ceramics via sol-gel process: novel high-energy-density capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Puli, Venkata Sreenivas; Kumar, Ashok; Scott, J F; Katiyar, Ram S [SPECLAB, Department of Physics, University of Puerto Rico, San Juan, PR 00936 (Puerto Rico); Chrisey, Douglas B; Tomozawa, M, E-mail: rkatiyar@uprrp.edu [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180-3590 (United States)

    2011-10-05

    Lead-free barium zirconate-titanate/barium calcium-titanate, [(BaZr{sub 0.2}Ti{sub 0.80})O{sub 3}]{sub 1-x}-[(Ba{sub 0.70}Ca{sub 0.30})TiO{sub 3}]{sub x} (x = 0.10, 0.15, 0.20) (BZT-BCT) ceramics with high dielectric constant, low dielectric loss and moderate electric breakdown field were prepared by the sol-gel synthesis technique. X-ray diffraction patterns revealed tetragonal crystal structure and this was further confirmed by Raman spectra. Well-behaved ferroelectric hysteresis loops and moderate polarizations (spontaneous polarization, P{sub s} {approx} 3-6 {mu}C cm{sup -2}) were obtained in these BZT-BCT ceramics. Frequency-dependent dielectric spectra confirmed that ferroelectric diffuse phase transition (DPT) exists near room temperature. Scanning electron microscope images revealed monolithic grain growth in samples sintered at 1280 deg. C. 1000/{epsilon} versus (T) plots revealed ferroelectric DPT behaviour with estimated {gamma} values of {approx}1.52, 1.51 and 1.88, respectively, for the studied BZT-BCT compositions. All three compositions showed packing-limited breakdown fields of {approx}47-73 kV cm{sup -1} with an energy density of 0.05-0.6 J cm{sup -3} for thick ceramics (>1 mm). Therefore these compositions might be useful in Y5V-type capacitor applications.

  5. Spectral K-edge subtraction imaging of experimental non-radioactive barium uptake in bone.

    Science.gov (United States)

    Panahifar, Arash; Samadi, Nazanin; Swanston, Treena M; Chapman, L Dean; Cooper, David M L

    2016-12-01

    To evaluate the feasibility of using non-radioactive barium as a bone tracer for detection with synchrotron spectral K-edge subtraction (SKES) technique. Male rats of 1-month old (i.e., developing skeleton) and 8-month old (i.e., skeletally mature) were orally dosed with low dose of barium chloride (33mg/kg/day Ba 2+ ) for 4weeks. The fore and hind limbs were dissected for imaging in projection and computed tomography modes at 100μm and 52μm pixel sizes. The SKES method utilizes a single bent Laue monochromator to prepare a 550eV energy spectrum to encompass the K-edge of barium (37.441keV), for collecting both 'above' and 'below' the K-edge data sets in a single scan. The SKES has a very good focal size, thus limits the 'crossover' and motion artifacts. In juvenile rats, barium was mostly incorporated in the areas of high bone turnover such as at the growth plate and the trabecular surfaces, but also in the cortical bone as the animals were growing at the time of tracer administration. However, the adults incorporated approximately half the concentration and mainly in the areas where bone remodeling was predominant and occasionally in the periosteal and endosteal layers of the diaphyseal cortical bone. The presented methodology is simple to implement and provides both structural and functional information, after labeling with barium, on bone micro-architecture and thus has great potential for in vivo imaging of pre-clinical animal models of musculoskeletal diseases to better understand their mechanisms and to evaluate the efficacy of pharmaceuticals. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  6. Synthesis and properties of nickel-doped nanocrystalline barium hexaferrite ceramic materials

    Science.gov (United States)

    Waqar, Moaz; Rafiq, Muhammad Asif; Mirza, Talha Ahmed; Khalid, Fazal Ahmad; Khaliq, Abdul; Anwar, Muhammad Sabieh; Saleem, Murtaza

    2018-04-01

    M-type barium hexaferrite ceramics have emerged as important materials both for technological and commercial applications. However, limited work has been reported regarding the investigation of nanocrystalline Ni-doped barium hexaferrites. In this study, nanocrystalline barium hexaferrite ceramics with the composition BaFe12- x Ni x O19 (where x = 0, 0.3 and 0.5) were synthesized by sol-gel method and characterized using X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, vibrating sample magnetometer and precision impedance analyzer. All the synthesized samples had single magnetoplumbite phase having space group P63/mmc showing the successful substitution of Ni in BaFe12O19 without the formation of any impurity phase. Average grain size of undoped samples was around 120 nm which increased slightly with the addition of Ni. Saturation magnetization ( M s) and remnant magnetization ( M r) increased with the addition of Ni, however, coercivity ( H c) decreased with the increase in Ni from x = 0 to x = 0.5. Real and imaginary parts of permittivity decreased with the increasing frequency and increased with Ni content. Dielectric loss and conductivity showed slight variation with the increase in Ni concentration.

  7. Laser-Induced Fluorescence diagnostic of barium ion plasmas in the Paul Trap Simulator Experiment

    International Nuclear Information System (INIS)

    Chung, Moses; Gilson, Erik P.; Davidson, Ronald C.; Efthimion, Philip C.; Majeski, Richard; Startsev, Edward A.

    2005-01-01

    The Paul Trap Simulator Experiment (PTSX) is a cylindrical Paul trap whose purpose is to simulate the nonlinear dynamics of intense charged particle beam propagation in alternating-gradient magnetic transport systems. To investigate the ion plasma microstate in PTSX, including the ion density profile and the ion velocity distribution function, a laser-induced fluorescence diagnostic system is being developed as a nondestructive diagnostic. Instead of cesium, which has been used in the initial phase of the PTSX experiment, barium has been selected as the preferred ion for the laser-induced fluorescence diagnostic. A feasibility study of the laser-induced fluorescence diagnostic using barium ions is presented with the characterization of a tunable dye laser. The installation of the barium ion source and the development of the laser-induced fluorescence diagnostic system are also discussed

  8. Stable isotopes of pedogenic carbonates from the Somma-Vesuvius area, southern Italy, over the past 18 kyr: palaeoclimatic implications

    Science.gov (United States)

    Zanchetta, G.; di Vito, M.; Fallick, A. E.; Sulpizio, R.

    2000-12-01

    Stable isotopes were measured in the carbonate and organic matter of palaeosols in the Somma-Vesuvius area, southern Italy in order to test whether they are suitable proxy records for climatic and ecological changes in this area during the past 18000 yr. The ages of the soils span from ca. 18 to ca. 3 kyr BP. Surprisingly, the Last Glacial to Holocene climate transition was not accompanied by significant change in 18O of pedogenic carbonate. This could be explained by changes in evaporation rate and in isotope fractionation between water and precipitated carbonate with temperature, which counterbalanced the expected change in isotope composition of meteoric water. Because of the rise in temperature and humidity and the progressive increase in tree cover during the Holocene, the Holocene soil carbonates closely reflect the isotopic composition of meteoric water. A cooling of about 2°C after the Avellino eruption (3.8 ka) accounts for a sudden decrease of about 1 in 18O of pedogenic carbonate recorded after this eruption. The 13C values of organic matter and pedogenic carbonate covary, indicating an effective isotope equilibrium between the organic matter, as the source of CO2, and the pedogenic carbonate. Carbon isotopes suggest prevailing C3 vegetation and negligible mixing with volcanogenic or atmospheric CO2.

  9. Impact of contamination and pre-treatment on stable carbon and nitrogen isotopic composition of charred plant remains.

    Science.gov (United States)

    Vaiglova, Petra; Snoeck, Christophe; Nitsch, Erika; Bogaard, Amy; Lee-Thorp, Julia

    2014-12-15

    Stable isotope analysis of archaeological charred plants has become a useful tool for interpreting past agricultural practices and refining ancient dietary reconstruction. Charred material that lay buried in soil for millennia, however, is susceptible to various kinds of contamination, whose impact on the grain/seed isotopic composition is poorly understood. Pre-treatment protocols have been adapted in distinct forms from radiocarbon dating, but insufficient research has been carried out on evaluating their effectiveness and necessity for stable carbon and nitrogen isotope analysis. The effects of previously used pre-treatment protocols on the isotopic composition of archaeological and modern sets of samples were investigated. An archaeological sample was also artificially contaminated with carbonates, nitrates and humic acid and subjected to treatment aimed at removing the introduced contamination. The presence and removal of the contamination were investigated using Fourier transform infrared spectroscopy (FTIR) and δ(13)C and δ(15)N values. The results show a ca 1‰ decrease in the δ(15)N values of archaeological charred plant material caused by harsh acid treatments and ultra-sonication. This change is interpreted as being caused by mechanical distortion of the grains/seeds rather than by the removal of contamination. Furthermore, specific infrared peaks have been identified that can be used to detect the three types of contaminants studied. We argue that it is not necessary to try to remove humic acid contamination for stable isotope analysis. The advantages and disadvantages of crushing the grains/seeds before pre-treatment are discussed. We recommend the use of an acid-only procedure (0.5 M HCl for 30 min at 80 °C followed by three rinses in distilled water) for cleaning charred plant remains. This study fills an important gap in plant stable isotope research that will enable future researchers to evaluate potential sources of isotopic change and pre

  10. Growth versus metabolic tissue replacement in mouse tissues determined by stable carbon and nitrogen isotope analysis

    Science.gov (United States)

    Macavoy, S. E.; Jamil, T.; Macko, S. A.; Arneson, L. S.

    2003-12-01

    Stable isotope analysis is becoming an extensively used tool in animal ecology. The isotopes most commonly used for analysis in terrestrial systems are those of carbon and nitrogen, due to differential carbon fractionation in C3 and C4 plants, and the approximately 3‰ enrichment in 15N per trophic level. Although isotope signatures in animal tissues presumably reflect the local food web, analysis is often complicated by differential nutrient routing and fractionation by tissues, and by the possibility that large organisms are not in isotopic equilibrium with the foods available in their immediate environment. Additionally, the rate at which organisms incorporate the isotope signature of a food through both growth and metabolic tissue replacement is largely unknown. In this study we have assessed the rate of carbon and nitrogen isotopic turnover in liver, muscle and blood in mice following a diet change. By determining growth rates, we were able to determine the proportion of tissue turnover caused by growth versus that caused by metabolic tissue replacement. Growth was found to account for approximately 10% of observed tissue turnover in sexually mature mice (Mus musculus). Blood carbon was found to have the shortest half-life (16.9 days), followed by muscle (24.7 days). Liver carbon turnover was not as well described by the exponential decay equations as other tissues. However, substantial liver carbon turnover was observed by the 28th day after diet switch. Surprisingly, these tissues primarily reflect the carbon signature of the protein, rather than carbohydrate, source in their diet. The nitrogen signature in all tissues was enriched by 3 - 5‰ over their dietary protein source, depending on tissue type, and the isotopic turnover rates were comparable to those observed in carbon.

  11. A versatile method for simultaneous stable carbon isotope analysis of DNA and RNA nucleotides by liquid chromatography/isotope ratio mass spectrometry

    NARCIS (Netherlands)

    Moerdijk-Poortvliet, T.C.W.; Brasser, J.; de Ruiter, G.; Houtekamer, M.; Bolhuis, H.; Stal, L.J.; Boschker, H.T.S.

    2014-01-01

    RATIONALELiquid chromatography/isotope ratio mass spectrometry (LC/IRMS) is currently the most accurate and precise technique for the measurement of compound-specific stable carbon isotope ratios (C-13/C-12) in biological metabolites, at their natural abundance. However, until now this technique

  12. Follow-up barium study after a negative water-soluble contrast examination for suspected esophageal leak: is it necessary?

    Science.gov (United States)

    Sanchez, Thomas R; Holz, Grant S; Corwin, Michael T; Wood, Robert J; Wootton-Gorges, Sandra L

    2015-10-01

    The purpose of this study was to determine the value of follow-up barium esophogram in diagnosing esophageal injury or leak if the initial water-soluble contrast examination of the esophagus is normal. An institutional review board (IRB)-approved retrospective review of all pediatric patients less than 18 years old referred to the radiology department for evaluation of esophageal injury or leak was performed for a 9-year period from 2005 to 2014. The majority of patients had unexplained pneumomediastinum, chest trauma (gunshot or puncture wound), or foreign body ingestion as the reason for the referral. Forty-nine patients (age range 10 days to 17 years) underwent an initial water-soluble esophogram immediately followed by a barium esophogram. Forty-six studies were negative on both water-soluble contrast and barium studies. Two studies were both positive on the initial water-soluble contrast and subsequent barium studies. A single study showed the esophageal leak only in the water-soluble study, with the follow-up barium exam being normal. The result of this study indicates that a single-contrast water-soluble esophogram alone is sensitive in the diagnosis of esophageal injury or leak. It has a 100 % sensitivity and negative predictive value. A follow-up barium esophogram only increases the study time and radiation dose to the patient.

  13. Carbon Stable Isotope Values in Plankton and Mussels Reflect Changes in Carbonate Chemistry Associated with Nutrient Enhanced Net Production

    Directory of Open Access Journals (Sweden)

    Autumn Oczkowski

    2018-02-01

    Full Text Available Coastal ecosystems are inherently complex and potentially adaptive as they respond to changes in nutrient loads and climate. We documented the role that carbon stable isotope (δ13C measurements could play in understanding that adaptation with a series of three Ecostat (i.e., continuous culture experiments. We quantified linkages among δ13C, nutrients, carbonate chemistry, primary, and secondary production in temperate estuarine waters. Experimental culture vessels (9.1 L containing 33% whole and 67% filtered (0.2 μm seawater were amended with dissolved inorganic nitrogen (N and phosphorous (P in low (3 vessels; 5 μM N, 0.3 μM P, moderate (3 vessels; 25 μM N, 1.6 μM P, and high amounts (3 vessels; 50 μM N, 3.1 μM P. The parameters necessary to calculate carbonate chemistry, chlorophyll-a concentrations, and particulate δ13C values were measured throughout the 14 day experiments. Outflow lines from the experimental vessels fed 250 ml containers seeded with juvenile blue mussels (Mytilus edulis. Mussel subsamples were harvested on days 0, 7, and 14 and their tissues were analyzed for δ13C values. We consistently observed that particulate δ13C values were positively correlated with chlorophyll-a, carbonate chemistry, and to changes in the ratio of bicarbonate to dissolved carbon dioxide (HCO3-:CO2. While the relative proportion of HCO3- to CO2 increased over the 14 days, concentrations of each declined, reflecting the drawdown of carbon associated with enhanced production. Plankton δ13C values, like chlorophyll-a concentrations, increased over the course of each experiment, with the greatest increases in the moderate and high treatments. Trends in δ13C over time were also observed in the mussel tissues. Despite ecological variability and different plankton abundances the experiments consistently demonstrated how δ13C values in primary producers and consumers reflected nutrient availability, via its impact on carbonate chemistry. We

  14. The barium-to-iron enrichment versus age relation of ancient disc stars

    Science.gov (United States)

    Fuhrmann, K.; Chini, R.; Kaderhandt, L.; Chen, Z.; Lachaume, R.

    2017-11-01

    We report an intrinsically precise relation of the barium-to-iron enrichment as a function of age for a local, volume-complete (N = 30) sample of ancient Population II (τ ≥ 12 Gyr) and intermediate-disc stars (τ ≃ 10 Gyr), which suggests a common, r-process-dominated nucleosynthesis site for both elements in the early stages of the Milky Way. Deviants from this empirical relation are to a large extent identified as formerly known or new blue straggler stars. We report in particular the striking case of the Population II star HD 159062, whose barium overabundance is difficult to explain without wind accretion of s-process material from a former asymptotic giant branch (AGB) primary that very likely survived as a white dwarf companion. The weak but significant barium enhancement that we measure for HR 3578 and 104 Tau also suggests that both may be accompanied by faint degenerate companions. If confirmed through precision astrometry or direct imaging observations, this would mean a very efficient method to uncover ancient stellar remnant companions around solar-type stars.

  15. Bioavailability of barium to plants and invertebrates in soils contaminated by barite.

    Science.gov (United States)

    Lamb, Dane T; Matanitobua, Vitukawalu P; Palanisami, Thavamani; Megharaj, Mallavarapu; Naidu, Ravi

    2013-05-07

    Barium (Ba) is a nonessential element to terrestrial organisms and is known to be toxic at elevated concentrations. In this study, the bioavailability and toxicity of Ba in barite (BaSO4) contaminated soils was studied using standard test organisms (Lactuca sativa L. "Great Lakes", Eisenia fetida). Contamination resulted from barite mining activities. Barium concentrations in contaminated soils determined by X-ray fluorescence were in the range 0.13-29.2%. Barite contaminated soils were shown to negatively impact both E. fetida and L. sativa relative to control soil. For E. fetida, pore-water concentrations and acid extractable Ba were linearly related to % body weight loss. In L. sativa, pore-water Ba and exchangeable Ba were both strongly related to shoot Ba and shoot biomass production. A negative linear relationship was observed between shoot Ba content and shoot weight (P Barium concentrations in pore-water were lower than predicted from barite solubility estimates but strongly related to exchangeable Ba, indicating an influence of ion exchange on Ba solubility and toxicity to E. fetida and L. sativa.

  16. Stable carbon and nitrogen incorporation in blood and fin tissue of the catfish Pterygoplichthys disjunctivus (Siluriformes, Loricariidae)

    OpenAIRE

    German, Donovan P.; Miles, Richard D.

    2010-01-01

    A feeding trial was performed in the laboratory with the catfish species Pterygoplichthys disjunctivus to determine stable carbon (13C) and nitrogen (15 N) turnover rates and discrimination factors in non-lethally sampled tissues (red blood cells, plasma solutes, and fin). A second feeding trial was conducted to determine what P. disjunctivus could assimilate from low-quality wood-detritus—refractory polysaccharides (e.g., cellulose), or soluble wood-degradation products inherent in wood-detr...

  17. A comparative study on production of stable carbon nano tube dispersions using gum arabic and sodium dodecyl sulphate

    International Nuclear Information System (INIS)

    Rashmi, W.; Ismail, A.F.; Jameel, A.T.; Yusof, F.; Khalid, M.; Mubarak, N.M.

    2009-01-01

    Full text: Improvements on the stability of carbon nano tube (CNT)-water suspensions are necessary to enhance the performance of CNT nano fluids. CNTs are usually packed into crystalline ropes that form strong networks due to Van der Waals attraction. Aggregation of these CNTs is obstacle to most of the applications which diminished its special properties. Thus, this paper aims to produce stable CNT dispersion using Gum Arabic (GA) and Sodium dodecyl sulphate (SDS) as dispersants. The CNT concentration is varied from 0.01-0.1 wt% while the concentration of dispersants is varied from 1-12 wt%, respectively. This work gives detailed information on effect of CNT concentration, dispersant concentration and sonication time on stability of CNT dispersions. UV-Vis Spectrophotometer was used to measure the concentration of CNTs with respect to sedimentation time. CNT-GA suspensions were found to be more stable compared to CNT-SDS suspensions. The homogeneous suspension of CNT-GA is stable for several months. (author)

  18. Effects of polyacrylic acid additive on barium sulfate particle morphology

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jie; Liu, Dandan; Jiang, Hongkun; Wang, Jun; Jing, Xiaoyan; Chen, Rongrong [Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Zhu, Wenting [Department of Gastroenterology, Harbin Medical University Cancer Hospital, Harbin 150081 (China); Han, Shihui [Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Li, Wanyou [College of Power and Energy Engineering, Harbin Engineering University, Harbin 150001 (China); Wei, Hao, E-mail: weihao7512@126.com [Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); College of Power and Energy Engineering, Harbin Engineering University, Harbin 150001 (China)

    2016-06-01

    In this paper, polyacrylic acid (PAA) was used as a growth modifier to control micron-sized barium sulfate particles via a simple precipitation reaction between sodium sulfate and barium chloride at ambient temperature. The barium sulfate particles were exhibited various morphologies, such as monodisperse spheres, ellipsoids, rose-like aggregates, etc. To better understand the formation mechanisms of the various morphologies of these particles, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA) were employed. It was found that the PAA concentration, pH, and Ba{sup 2+} and SO{sub 4}{sup 2−} ions concentrations were the most important parameters controlling the morphology of the BaSO{sub 4} particles. These parameters affected the BaSO{sub 4} morphology by influencing the interactions between the PAA carboxyl groups and inorganic ions and the conformation change of the PAA molecular chains. Moreover, this work attempts to provide a preliminary understanding of the formation of the spherical BaSO{sub 4} particles with the randomly coiled conformation of the polymer. - Highlights: • Polyacrylic acid (PAA) was used as a growth modifier to control micron-sized BaSO{sub 4} particles. • The PAA/BaSO{sub 4} particles were exhibited various morphologies. • Provide a preliminary understanding of the formation mechanism of BaSO{sub 4} particles.

  19. Magnetic studies of cobalt doped barium hexaferrite nanoparticles prepared by modified sol-gel method

    International Nuclear Information System (INIS)

    Shalini, M. Govindaraj; Sahoo, Subasa C.

    2016-01-01

    M-type barium hexaferrite (BaFe_1_2O_1_9) and cobalt doped barium hexaferrite (BaFe_1_1CoO_1_9) nanopowders were synthesized by modified sol-gel auto-combustion technique and were annealed at 900°C in air for 4 hours. The annealed powders were studied in the present work and X-ray diffraction studies showed pure phase formation after annealing. The average grain size in the nanopowder sample was decreased after doping. Magnetization value of 60 emu/g was observed at 300 K for the barium hexaferrite and was reduced to 54 emu/g after doping. The coercivity of 5586 Oe was observed at 300 K for the undoped sample and was found to be decreased in the doped sample. As the measurement temperature was decreased from 300 K to 60 K, magnetization value was increased in both the samples compared to those at 300 K. The coercivity of the undoped sample was found to decrease whereas it was increased for the doped sample at 60 K. The observed magnetic properties may be understood on the basis of modified exchange interaction and anisotropy in the doped sample compared to that of pure barium hexaferrite.

  20. Method of selective dissolution for characterization of particulate forms of radium and barium in natural and waste waters

    International Nuclear Information System (INIS)

    Benes, P.; Sedlacek, J.; Sebesta, F.; Sandrik, R.

    1981-01-01

    A new method is proposed for characterization of particulate forms of radium and barium in natural and waste waters. Particulate solids suspended in 1-3 l. of water are first concentrated by membrane filtration or by centrifugation to 20-50 ml of a concentrate which is then filtered through a small-size membrane filter. The solids retained by the filter are successively washed with three selective solvents releasing ''loosely bound'', ''acid soluble'' and ''barium sulfate'' forms of radium and barium. Compositions and volumes of the selective solvents have been chosen using model experiments and partially checked by analysis of natural samples. Radium and barium ''in crystalline detritus'' remain on the filter and are determined after an acid digestion of the filter. The principal criteria and selectivity of the method are discussed. (author)

  1. Effect of barium sulfate contrast medium on rheology and sensory texture attributes in a model food.

    Science.gov (United States)

    Ekberg, O; Bulow, M; Ekman, S; Hall, G; Stading, M; Wendin, K

    2009-03-01

    The swallowing process can be visualized using videoradiography, by mixing food with contrast medium, e.g., barium sulfate (BaSO(4)), making it radiopaque. The sensory properties of foods may be affected by adding this medium. To evaluate if and to what extent sensory and rheological characteristics of mango purée were altered by adding barium sulfate to the food. This study evaluated four food samples based on mango purée, with no or added barium sulfate contrast medium (0%, 12.5%, 25.0%, and 37.5%), by a radiographic method, and measured sensory texture properties and rheological characteristics. The sensory evaluation was performed by an external trained panel using quantitative descriptive analysis. The ease of swallowing the foods was also evaluated. The sensory texture properties of mango purée were significantly affected by the added barium in all evaluated attributes, as was the perception of particles. Moreover, ease of swallowing was significantly higher in the sample without added contrast medium. All samples decreased in extensional viscosity with increasing extension rate, i.e., all samples were tension thinning. Shear viscosity was not as dependent on the concentration of BaSO(4) as extensional viscosity. Addition of barium sulfate to a model food of mango purée has a major impact on perceived sensory texture attributes as well as on rheological parameters.

  2. Assessing dissolved carbon transport and transformation along an estuarine river with stable isotope analyses

    Science.gov (United States)

    He, Songjie; Xu, Y. Jun

    2017-10-01

    Estuaries play an important role in the dynamics of dissolved carbon from rivers to coastal oceans. However, our knowledge of dissolved carbon transport and transformation in mixing zones of the world's coastal rivers is still limited. This study aims to determine how dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) concentrations and stable isotopes (δ13CDIC and δ13CDOC) change along an 88-km long estuarine river, the Calcasieu River in Louisiana, southern USA, with salinity ranging from 0.02 to 21.92. The study is expected to elucidate which processes most likely control carbon dynamics in a freshwater-saltwater mixing system, and to evaluate the net metabolism of this estuary. Between May 2015 and February 2016, water samples were collected and in-situ measurements on ambient water conditions were performed during five field trips at six sites from upstream to downstream of the Calcasieu River, which enters the Northern Gulf of Mexico (NGOM). The DIC concentration and δ13CDIC increased rapidly with increasing salinity in the mixing zone. The average DIC concentration and δ13CDIC at the site closest to the NGOM (site 6) were 1.31 mM and -6.34‰, respectively, much higher than those at the site furthest upstream (site 1, 0.42 mM and -20.83‰). The DIC concentrations appeared to be largely influenced by conservative mixing, while high water temperature may have played a role in deviating DIC concentration from the conservative line due likely to increased respiration and decomposition. The δ13CDIC values were close to those suggested by the conservative mixing model for May, June and November, but lower than those for July and February, suggesting that an estuarine river can fluctuate from a balanced to a heterotrophic system (i.e., production/respiration (P/R) aquatic photosynthesis from carbon produced by terrestrial photosynthesis in a river-ocean continuum.

  3. MDCT appearance of the appendix: how does the low-density barium sulfate oral contrast agent affect it?

    Science.gov (United States)

    Yaghmai, Vahid; Aghaei-Lasboo, Anahita; Brandwein, Warren M; Tochetto, Sandra; Mafi, John N; Miller, Frank H; Nikolaidis, Paul

    2011-01-01

    We compared the effect of low-density barium sulfate neutral oral contrast agent on the diameter of normal appendix and its luminal content versus that of water on multidetector-row CT. CT scans of 24 patients who had been imaged on two separate occasions for the evaluation of pancreatic pathology, once with water and subsequently with low-density barium sulfate as the neutral oral contrast agent were evaluated (total of 48 scans). Studies were randomized and reviewed in consensus on a workstation in the stack mode by two radiologists blinded to the type of oral contrast. The appendix was measured at baseline and 10 days later to obtain an average diameter. Results of the water and low-density barium sulfate groups were compared using paired t test. Contents of the appendiceal lumen were also noted (gas, fluid, mixed, and collapsed appendix). The average diameter of the appendix for scans obtained with water and low-density barium sulfate was 4.09 ± 0.87 mm (median, 4.22 mm; range, 2.50-5.65 mm) and 4.13 ± 0.93 mm (median, 4 mm, range, 2.2-5.65 mm), respectively. This difference was not statistically significant (P = 0.69). There was no statistically significant difference in the appendiceal content when water or low-density barium sulfate were used as oral contrast (χ (2) = 4.25, P = 0.89). Low-density barium sulfate does not affect appendiceal content or diameter and, therefore, should not adversely affect evaluation of the appendix on multidetector row CT.

  4. Generation of sub-100-fs Stokes pulses upon SRS in a barium nitrate crystal

    International Nuclear Information System (INIS)

    Konyashchenko, Aleksandr V; Losev, Leonid L; Tenyakov, S Yu

    2010-01-01

    72-fs pulses are generated at the first Stokes component frequency upon stimulated Raman scattering in a barium nitrate crystal for the radiation of the Ti 3+ :Al 2 O 3 laser with the pulse duration of 50 fs. The energy efficiency of conversion is 20%. The barium nitrate crystal was optically pumped by two consecutive orthogonally polarised chirped pulses with the following time compression of the Stokes radiation pulse. (nonlinear optical phenomena)

  5. Stable carbon isotopes as an indicator for soil degradation in an alpine environment (Urseren Valley, Switzerland).

    Science.gov (United States)

    Schaub, Monika; Alewell, Christine

    2009-05-01

    Analyses of soil organic carbon (SOC) content and stable carbon isotope signatures (delta(13)C) of soils were assessed for their suitability to detect early stage soil erosion. We investigated the soils in the alpine Urseren Valley (southern central Switzerland) which are highly impacted by soil erosion. Hill slope transects from uplands (cambisols) to adjacent wetlands (histosols and histic to mollic gleysols) differing in their intensity of visible soil erosion, and reference wetlands without erosion influence were sampled. Carbon isotopic signature and SOC content of soil depth profiles were determined. A close correlation of delta(13)C and carbon content (r > 0.80) is found for upland soils not affected by soil erosion, indicating that depth profiles of delta(13)C of these upland soils mainly reflect decomposition of SOC. Long-term disturbance of an upland soil is indicated by decreasing correlation of delta(13)C and SOC (r soil erosion in hill slope transects from uplands to adjacent wetlands is documented as an intermediate delta(13)C value (-27.5 per thousand) for affected wetland soil horizons (0-12 cm) between upland (aerobic metabolism, relatively heavier delta(13)C of -26.6 per thousand) and wetland isotopic signatures (anaerobic metabolism, relatively lighter delta(13)C of -28.6 per thousand). Carbon isotopic signature and SOC content are found to be sensitive indicators of short- and long-term soil erosion processes. Copyright (c) 2009 John Wiley & Sons, Ltd.

  6. Distribution and source of barium in ground water at Cattaraugus Indian Reservation, southwestern New York

    Science.gov (United States)

    Moore, R.B.; Staubitz, W.W.

    1984-01-01

    High concentrations of dissolved barium have been found in ground water from bedrock wells on the Seneca Nation of Indians Reservation on Cattaraugus Creek in southwestern New York. Concentrations in 1982 were as high as 23.0 milligrams per liter , the highest found reported from any natural ground-water system in the world. The highest concentrations are in a bedrock aquifer and in small lenses of saturated gravel between bedrock and the overlying till. The bedrock aquifer is partly confined by silt, clay, and till. The high barium concentrations are attributed to dissolution of the mineral barite (BaSO4), which is present in the bedrock and possibly in overlying silt, clay, or till. The dissolution of barite seems to be controlled by action of sulfate-reducing bacteria, which alter the BaSO4 equilibrium by removing sulfate ions and permitting additional barite to dissolve. Ground water from the surficial, unconsolidated deposits and surface water in streams contain little or no barium. Because barium is chemically similar to calcium, it probably could be removed by cation exchange or treatments similar to those used for water softening. (USGS)

  7. Multiple electrical phase transitions in Al substituted barium hexaferrite

    Science.gov (United States)

    Kumar, Sunil; Supriya, Sweety; Kar, Manoranjan

    2017-12-01

    Barium hexaferrite is known to be a very good ferromagnetic material. However, it shows very good dielectric properties, i.e., the dielectric constant is comparable to that of the ferroelectric material. However, its crystal symmetry does not allow it to be a ferroelectric material. Hence, the electrical properties have revived the considerable research interest on these materials, not only for academic interest, but also for technological applications. There are a few reports on temperature dependent dielectric behavior of these materials. However, the exact cause of dielectric as well as electrical conductivity is yet to be established. Hence, Al (very good conducting material) substituted barium hexaferrite (BaFe12-xAlxO19, x = 0.0-4.0) has been prepared by following the modified sol-gel method to understand the ac and DC electrical properties of these materials. The crystal structure and parameters have been studied by employing the XRD and FTIR techniques. There are two transition temperatures, which have been observed in the temperature dependent ac dielectric and DC resistivity measurement. The response of dielectric behaviors to temperature is similar to that of the ferroelectric material; however, the dielectric polarization is due to the polaron hopping, which is evident from the DC resistivity analysis. Hence, the present observations lead to understand the electrical properties of barium hexaferrite. The frequency dependent dielectric dispersion can be understood by the modified Debye model. More interestingly, the dielectric constant decreases and DC resistivity increases with the increase in the Al concentration, which has the correlation between bond length modifications in the crystal due to substitution.

  8. Short-cavity squeezing in barium

    Science.gov (United States)

    Hope, D. M.; Bachor, H-A.; Manson, P. J.; Mcclelland, D. E.

    1992-01-01

    Broadband phase sensitive noise and squeezing were experimentally observed in a system of barium atoms interacting with a single mode of a short optical cavity. Squeezing of 13 +/- 3 percent was observed. A maximum possible squeezing of 45 +/- 8 percent could be inferred for out experimental conditions, after correction for measured loss factors. Noise reductions below the quantum limit were found over a range of detection frequencies 60-170 MHz and were best for high cavity transmission and large optical depths. The amount of squeezing observed is consistent with theoretical predictions from a full quantum statistical model of the system.

  9. Duodenal diverticula demonstrated by barium examination

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, T.; Thommesen, P.

    An investigation for biliary tract calculi and food-stimulated gastro-oesophageal reflux was carried out in 37 patients with duodenal diverticula demonstrated by barium examination. Sixty per cent of the diverticula were located in the descending part of the duodenum. Biliary tract calculi were demonstrated in 38 per cent and food-stimulated gastro-oesophageal reflux in 81 per cent of the patients. The detection of a duodenal diverticulum should result in a supplementary investigation for gallstones and gastrooesophageal reflux and its sequelae.

  10. Diagnosis of gastro-oesophageal reflux in children. Comparison between oesophageal pH and barium examinations

    Energy Technology Data Exchange (ETDEWEB)

    Al-Khawari, Hanaa A. [Department of Radiology, Al-Amiri Hospital, Kuwait University (Kuwait); Sinan, T.S. [Department of Radiology, Mubarak Al-Kabeer Hospital, Kuwait University (Kuwait); Seymour, Helen [Department of Radiology, St George' s Hospital, Blackshaw Road, London SW17 0QT (United Kingdom)

    2002-11-01

    Gastro-oesophageal reflux (GOR) is a common disorder encountered during childhood. Early diagnosis and treatment is essential to prevent serious complications. There are several methods for the diagnosis of GOR, with variable opinions regarding which one is the most sensitive and specific. Objective. This is a retrospective study comparing 24-h oesophageal pH monitoring and barium examinations in the diagnosis of GOR in children. Patients and methods. All children referred with signs and/or symptoms of GOR from January to December 1996 at Great Ormond Street Hospital, London, UK, were included in the study. The recorded results (presence or absence of reflux) of barium examinations and 24-h oesophageal pH monitoring studies performed on 169 children were retrospectively reviewed and compared. Results. One-third of patients were below 1 year of age. In all age groups, oesophageal pH probe studies showed a high detection rate (83%) and low incidence of false-negative results (7%) compared to barium examinations, which showed a lower detection rate (43%) and higher incidence of false-negative results (48%). Most GOR-related anatomical abnormalities diagnosed by barium examinations were identified in infants below 1 year of age. Conclusions. We believe that 24-h oesophageal pH monitoring should be used as the first line of investigation for the diagnosis of GOR in all children regardless of the age group. Barium examinations can be reserved for patients below 1 year of age, those going for surgery and those with negative oesophageal pH monitoring results but strong clinical suspicion of GOR. (orig.)

  11. Investigation of the process of co-crystallization of barium and strontium nitrates from the system acetic acid-water

    International Nuclear Information System (INIS)

    Hubicki, W.; Piskorek, M.

    1976-01-01

    Co-crystallization of barium nitrate and strontium nitrate from the system CH 3 COOH-H 2 O was investigated by using radioactive tracer Ba 133 . The authors have found that during the crystallization of strontium nitrate from acetic acid solution at 25 0 C, one can obtain a 67-fold lowering of the content of barium in strontium nitrate, a 40-fold lowering of the content of barium in strontium nitrate is at 35 0 C. Strontium nitrate went to the solid phase with 70% efficiency. Acetic acid solutions of 24.5-24.3 per cent weight were used. Attention was paid to the franctionation of barium admixtures during crystallization of strontium nitrate from acetic acid solutions (so called ''isothermic salting out crystallization process'') is in agreement with the logarithmic law of Doerner-Hoskins. Process is characterized by a constant coefficient of surface co-crystallization lambda = 18. The results of investigations show that it is possible to obtain spectrally pure non-barium strontium nitrate as the result of its crystallization from the system CH 3 COOH-H 2 O at a temperature of 25 0 and 35 0 C. (author)

  12. A novel high-temperature combustion based system for stable isotope analysis of dissolved organic carbon in aqueous samples. : I development and validation

    NARCIS (Netherlands)

    Federherr, E.; Cerli, C.; Kirkels, F. M. S. A.; Kalbitz, K.; Kupka, H. J.; Dunsbach, R.; Lange, L.; Schmidt, T. C.

    2014-01-01

    RATIONALE: Traditionally, dissolved organic carbon (DOC) stable isotope analysis (SIA) is performed using either offline sample preparation followed by elemental analyzer/isotope ratiomass spectrometry (EA/IRMS) or a wet chemical oxidation (WCO)-based device coupled to an isotope ratio mass

  13. Tracing carbon sources through aquatic and terrestrial food webs using amino acid stable isotope fingerprinting.

    Directory of Open Access Journals (Sweden)

    Thomas Larsen

    Full Text Available Tracing the origin of nutrients is a fundamental goal of food web research but methodological issues associated with current research techniques such as using stable isotope ratios of bulk tissue can lead to confounding results. We investigated whether naturally occurring δ(13C patterns among amino acids (δ(13CAA could distinguish between multiple aquatic and terrestrial primary production sources. We found that δ(13CAA patterns in contrast to bulk δ(13C values distinguished between carbon derived from algae, seagrass, terrestrial plants, bacteria and fungi. Furthermore, we showed for two aquatic producers that their δ(13CAA patterns were largely unaffected by different environmental conditions despite substantial shifts in bulk δ(13C values. The potential of assessing the major carbon sources at the base of the food web was demonstrated for freshwater, pelagic, and estuarine consumers; consumer δ(13C patterns of essential amino acids largely matched those of the dominant primary producers in each system. Since amino acids make up about half of organismal carbon, source diagnostic isotope fingerprints can be used as a new complementary approach to overcome some of the limitations of variable source bulk isotope values commonly encountered in estuarine areas and other complex environments with mixed aquatic and terrestrial inputs.

  14. Tracing carbon sources through aquatic and terrestrial food webs using amino acid stable isotope fingerprinting.

    Science.gov (United States)

    Larsen, Thomas; Ventura, Marc; Andersen, Nils; O'Brien, Diane M; Piatkowski, Uwe; McCarthy, Matthew D

    2013-01-01

    Tracing the origin of nutrients is a fundamental goal of food web research but methodological issues associated with current research techniques such as using stable isotope ratios of bulk tissue can lead to confounding results. We investigated whether naturally occurring δ(13)C patterns among amino acids (δ(13)CAA) could distinguish between multiple aquatic and terrestrial primary production sources. We found that δ(13)CAA patterns in contrast to bulk δ(13)C values distinguished between carbon derived from algae, seagrass, terrestrial plants, bacteria and fungi. Furthermore, we showed for two aquatic producers that their δ(13)CAA patterns were largely unaffected by different environmental conditions despite substantial shifts in bulk δ(13)C values. The potential of assessing the major carbon sources at the base of the food web was demonstrated for freshwater, pelagic, and estuarine consumers; consumer δ(13)C patterns of essential amino acids largely matched those of the dominant primary producers in each system. Since amino acids make up about half of organismal carbon, source diagnostic isotope fingerprints can be used as a new complementary approach to overcome some of the limitations of variable source bulk isotope values commonly encountered in estuarine areas and other complex environments with mixed aquatic and terrestrial inputs.

  15. Routine filtration for decubitus radiography during double contrast barium enema examinations

    International Nuclear Information System (INIS)

    Camellini, V.; Abelli, P.; Marconi, G.

    1987-01-01

    A wedge-shaped plexiglass compensation filter for use in lateral decubitus radiographs of double contrast barium enema examinations has been designed. This filter, which has been used since February 1985, was compared with a second plexiglass filter, made by E-Z-EM. Voltage and amperage were kept contrast. Two different experiments were conducted in order to demonstrate the benefits of routine use of this compensation filter. First, the changes in skin dose were assessed using an ionization chamber on phantom. Secondly, three radiologists examined a series of 80 consecutive barium enemas without knowing which had been performed using the new filter. Out of the 70 examinations they considered excellent, as many as 45 had been performed with the new filter. Personal experience and the studies described show that the use of a compensation filter improves the accuracy and thus the diagnostic quality of the examinations as it enhances the detail of the anatomic structure of the colon; moreover the filter reduces skin exposure by up to 73.1% (EZ-E-EM filter 47.3%) and, at the same time, less radiographic films are needed. Routine use of a plexiglass compensation filter in lateral decubitus radiographs while performing a double contrast barium enema examination, is strongly recommended especially in obese patients

  16. A stable high-speed rotational transmission system based on nanotubes

    International Nuclear Information System (INIS)

    Cai, Kun; Yin, Hang; Wei, Ning; Chen, Zhen; Shi, Jiao

    2015-01-01

    A stable rotational transmission system is designed with a single-walled carbon nanotube (SWCNT)-based motor and double-walled carbon nanotubes (DWCNTs)-based bearing. The system response is investigated using molecular dynamics (MD) simulation. It is found that the rotating motor can actuate the rotation of the inner tube in bearing because of the attraction between the two adjacent coaxial ends of motor and rotor (the inner tube in bearing). To have a stable nanostructure, each carbon atom on the adjacent ends of motor and rotor is bonded with a hydrogen atom. To obtain a stable high-speed rotational transmission system, both an armchair and a zigzag model are used in MD simulation. In each model, the motor with different diameters and rotational speeds is employed to examine the rotational transmission of corresponding DWCNTs. It is demonstrated that the long range van der Waals interaction between the adjacent ends of motor and rotor leads to a stable configuration of the adjacent ends, and further leads to a stable rotation of rotor when driven by a high-speed motor. As compared with the armchair model, the rotor in the zigzag model could reach a stable rotation mode much easier

  17. Effects of sewage contamination on macro-algae and shellfish at Moa Point, New Zealand, using stable carbon and nitrogen isotopes

    International Nuclear Information System (INIS)

    Rogers, K.M.

    1999-01-01

    Stable carbon and nitrogen isotopes have been used to characterise sewage discharge and effects on seaweed (Ulva lactuca L.), blue mussels (Mytilus galloprovincialis), and limpets (Cellana denticulata) from Moa Point Bay, New Zealand. The nitrogen ( 15 N / 14 N) ratio is shown to be a good tracer of sewage pollution in Ulva lactuca and associated grazers (Cellana denticulata) as a result of the increased contribution of urea and ammonia to the surrounding marine environment from the sewage outfall. The carbon ( 13 C / 12 C) ratio is suggested as a more appropriate sewer tracer for mussels (Mytilus galloprovincialis), which filter feed the particulate organic matter from the effluent. Lower carbon : nitrogen ratios were found in U. lactuca sampled from the outfall region, compared to uncontaminated control sites, however carbon : nitrogen ratios do not vary significantly amongst shellfish species. (author). 18 refs., 4 figs., 2 tabs

  18. Detection of colonic polyps in the elderly: Optimization of the single-contrast barium enema examination

    International Nuclear Information System (INIS)

    Gelfand, D.W.; Chen, Y.M.; Ott, D.J.; Munitz, H.A.

    1986-01-01

    Single-contrast studies account for 75% of barium enema examinations and are often performed in the elderly. By optimizing all factors, the following results were obtained: for polyps of less than 1 cm, 40 of 57 were detected (sensitivity, 70.2%); for polyps of 1 cm or larger, 33 of 35 were detected (sensitivity, 94%). Overall, 73 of 92 polyps were detected (sensitivity, 79.3%). These sensitivities result from meticulous preparation and the use of compression filming, low-density barium, moderate kilovoltages, high-resolution screens, remote control apparatus, and high-bandpass TV fluoroscopy. The authors conclude that an optimal single-contrast barium enema examination detects colonic polyps with a sensitivity approaching that of the double-contrast study and may be employed in elderly patients who cannot undergo the double-contrast study

  19. Mapping of strain mechanisms in barium titanate by three-dimensional X-ray diffraction

    DEFF Research Database (Denmark)

    Majkut, Marta

    This thesis presents an in-situ three-dimensional study of the grain-scale response of a prototypical piezoelectric ceramic, barium titanate (BT), to an exernally applied electric field. Piezoceramics take advantage of the coupling of electrical and mechanical energies for use in sensors and actu......This thesis presents an in-situ three-dimensional study of the grain-scale response of a prototypical piezoelectric ceramic, barium titanate (BT), to an exernally applied electric field. Piezoceramics take advantage of the coupling of electrical and mechanical energies for use in sensors...

  20. Electrical transport properties of calcium and barium aluminates

    NARCIS (Netherlands)

    Metselaar, R.; Hoefsloot, A.M.

    1987-01-01

    Electrical conductivity and ionic transport numbers have been measured of barium and calcium aluminates with composition CaO·nAl2O3 (n=7/12, 1, 2, 6) and 0.82 BaO·6Al2O3. At room temperatures these compounds are insulators, but at high temperatures mixed conductivity is observed. Ionic transport