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1

Barium Sulfate  

MedlinePLUS

Cheetah® ... Barium sulfate is used to help doctors examine the esophagus (tube that connects the mouth and stomach), stomach, ... dimensional pictures of the inside of the body). Barium sulfate is in a class of medications called radiopaque ...

2

RADIOCHEMICAL STUDY OF THE PARTIAL PROCESS OF BARIUM SULFATE PRECIPITATION. I. DESCRIPTION OF METHOD AND EXPERIMENTAL PART  

Microsoft Academic Search

To gain insight into the partial process of barium sulfate ; precipitation, a radiochemical method was developed. The principle on which the ; method is based involves the addition of carrier-free Ba¹⁴° in ; radiochemical equilibrium with La¹⁴° before precipitation at different ; times after the beginning of precipitation. After the beginning of precipitation ; or after the addition of

K. H. Lieser; A. Fabrikanos

1959-01-01

3

Effects of nitrate and water on the oxygen isotopic analysis of barium sulfate precipitated from solution  

USGS Publications Warehouse

BaSO4 precipitated from mixed salt solutions by common techniques for SO isotopic analysis may contain quantities of H2O and NOthat introduce errors in O isotope measurements. Experiments with synthetic solutions indicate that ?18O values of CO produced by decomposition of precipitated BaSO4 in a carbon reactor may be either too low or too high, depending on the relative concentrations of SO and NO and the ?18O values of the H2O, NO, and SO. Typical ?18O errors are of the order of 0.5 to 1‰ in many sample types, and can be larger in samples containing atmospheric NO, which can cause similar errors in ?17O and ?17O. These errors can be reduced by (1) ion chromatographic separation of SO from NO, (2) increasing the salinity of the solutions before precipitating BaSO4 to minimize incorporation of H2O, (3) heating BaSO4 under vacuum to remove H2O, (4) preparing isotopic reference materials as aqueous samples to mimic the conditions of the samples, and (5) adjusting measured ?18O values based on amounts and isotopic compositions of coexisting H2O and NO. These procedures are demonstrated for SO isotopic reference materials, synthetic solutions with isotopically known reagents, atmospheric deposition from Shenandoah National Park, Virginia, USA, and sulfate salt deposits from the Atacama Desert, Chile, and Mojave Desert, California, USA. These results have implications for the calibration and use of O isotope data in studies of SOsources and reaction mechanisms.

Hannon, Janet E.; Bohlke, Johnkarl F.; Mroczkowski, Stanley J.

2008-01-01

4

Effects of nitrate and water on the oxygen isotopic analysis of barium sulfate precipitated from water samples  

USGS Publications Warehouse

BaSO4 precipitated from mixed salt solutions by common techniques for SO42- isotopic analysis may contain quantities of H2O and NO3- that introduce errors in O isotope measurements. Experiments with synthetic solutions indicate that ??18O values of CO produced by decomposition of precipitated BaSO4 in a carbon reactor may be either too low or too high, depending on the relative concentrations of SO42- and NO3- and the ??18O values of the H2O, NO3-, and SO42-. Typical ??18O errors are of the order of 0.5 to 1??? in many sample types, and can be larger in samples containing atmospheric NO 3-, which can cause similar errors in ?? 17O and ??17O. These errors can be reduced by (1) ion chromatographic separation of SO42- from NO 3-, (2) increasing the salinity of the solutions before precipitating BaSO4 to minimize incorporation of H2O, (3) heating BaSO4 under vacuum to remove H2O, (4) preparing isotopic reference materials as aqueous samples to mimic the conditions of the samples, and (5) adjusting measured ??18O values based on amounts and isotopic compositions of coexisting H2O and NO 3-. These procedures are demonstrated for SO 42- isotopic reference materials, synthetic solutions with isotopically known reagents, atmospheric deposition from Shenandoah National Park, Virginia, USA, and sulfate salt deposits from the Atacama Desert, Chile, and Mojave Desert, California, USA. These results have implications for the calibration and use of O isotope data in studies of SO42- sources and reaction mechanisms.

Hannon, J.E.; Böhlke, J.K.; Mroczkowski, S.J.

2008-01-01

5

Co-precipitation of radium with barium and strontium sulfate and its impact on the fate of radium during treatment of produced water from unconventional gas extraction.  

PubMed

Radium occurs in flowback and produced waters from hydraulic fracturing for unconventional gas extraction along with high concentrations of barium and strontium and elevated salinity. Radium is often removed from this wastewater by co-precipitation with barium or other alkaline earth metals. The distribution equation for Ra in the precipitate is derived from the equilibrium of the lattice replacement reaction (inclusion) between the Ra(2+) ion and the carrier ions (e.g., Ba(2+) and Sr(2+)) in aqueous and solid phases and is often applied to describe the fate of radium in these systems. Although the theoretical distribution coefficient for Ra-SrSO4 (Kd = 237) is much larger than that for Ra-BaSO4 (Kd = 1.54), previous studies have focused on Ra-BaSO4 equilibrium. This study evaluates the equilibria and kinetics of co-precipitation reactions in Ra-Ba-SO4 and Ra-Sr-SO4 binary systems and the Ra-Ba-Sr-SO4 ternary system under varying ionic strength (IS) conditions that are representative of brines generated during unconventional gas extraction. Results show that radium removal generally follows the theoretical distribution law in binary systems and is enhanced in the Ra-Ba-SO4 system and restrained in the Ra-Sr-SO4 system by high IS. However, the experimental distribution coefficient (Kd') varies widely and cannot be accurately described by the distribution equation, which depends on IS, kinetics of carrier precipitation and does not account for radium removal by adsorption. Radium removal in the ternary system is controlled by the co-precipitation of Ra-Ba-SO4, which is attributed to the rapid BaSO4 nucleation rate and closer ionic radii of Ra(2+) with Ba(2+) than with Sr(2+). Carrier (i.e., barite) recycling during water treatment was shown to be effective in enhancing radium removal even after co-precipitation was completed. Calculations based on experimental results show that Ra levels in the precipitate generated in centralized waste treatment facilities far exceed regulatory limits for disposal in municipal sanitary landfills and require careful monitoring of allowed source term loading (ASTL) for technically enhanced naturally occurring materials (TENORM) in these landfills. Several alternatives for sustainable management of TENORM are discussed. PMID:24670034

Zhang, Tieyuan; Gregory, Kelvin; Hammack, Richard W; Vidic, Radisav D

2014-04-15

6

Barium Sulfate Scale Formation in Oil Reservoir During Water Injection at High-Barium Formation Water  

NASA Astrophysics Data System (ADS)

This study presents the results of laboratory experiments carried out to investigate the formation of barium sulfate in sandstone cores from mixing injected sea water and formation water contain high concentration of barium at various temperatures (50 and 80°C) and differential pressures (100, 150 and 200 psig). The morphology of scaling crystals as shown by Scanning Electron Microscopy (SEM) is presented. Results show a large extent of permeability damage caused by barium sulfate deposits on the rock pore surface. The rock permeability decline indicates the influence of the concentration of barium ions.

Merdhah, Amer Badr Bin; Mohd Yassin, Abu Azam

7

Biokinetics and effects of barium sulfate nanoparticles.  

PubMed

BackgroundNanoparticulate barium sulfate has potential novel applications and wide use in the polymer and paint industries. Only a short-term inhalation study on barium sulfate nanoparticles (BaSO4 NPs) has been published [Part Fibre Toxicol 11:16, 2014]. We performed comprehensive biokinetic studies of 131BaSO4 NPs administered via different routes and of acute and subchronic pulmonary responses to instilled or inhaled BaSO4 in rats.MethodsWe compared the tissue distribution of 131Ba over 28 days after intratracheal (IT) instillation, and over 7 days after gavage and intravenous (IV) injection of 131BaSO4. Rats were exposed to 50 mg/m3 BaSO4 aerosol for 4 or 13 weeks (6 h/day, 5 consecutive days/week), gross and histopathology, blood and bronchoalveolar lavage (BAL) fluid analyses were performed. BAL fluid from instilled rats was also analyzed.ResultsInhaled BaSO4 NPs showed no toxicity after 4-week exposure, but a slight neutrophil increase in BAL after 13-week exposure was observed. Lung burden of inhaled BaSO4 NPs after 4-week exposure (0.84¿±¿0.18 mg/lung) decreased by 95% over 34 days. Instilled BaSO4 NPs caused dose-dependent inflammatory responses in the lungs. Instilled BaSO4 NPs (0.28 mg/lung) was cleared with a half-life of¿¿¿9.6 days. Translocated 131Ba from the lungs was predominantly found in the bone (29%). Only 0.15% of gavaged dose was detected in all organs at 7 days. IV-injected 131BaSO4 NPs were predominantly localized in the liver, spleen, lungs and bone at 2 hours, but redistributed from the liver to bone over time. Fecal excretion was the dominant elimination pathway for all three routes of exposure.ConclusionsPulmonary exposure to instilled BaSO4 NPs caused dose-dependent lung injury and inflammation. Four-week and 13-week inhalation exposures to a high concentration (50 mg/m3) of BaSO4 NPs elicited minimal pulmonary response and no systemic effects. Instilled and inhaled BaSO4 NPs were cleared quickly yet resulted in higher tissue retention than when ingested. Particle dissolution is a likely mechanism. Injected BaSO4 NPs localized in the reticuloendothelial organs and redistributed to the bone over time. BaSO4 NP exhibited lower toxicity and biopersistence in the lungs compared to other poorly soluble NPs such as CeO2 and TiO2. PMID:25331813

Konduru, Nagarjun; Keller, Jana; Ma-Hock, Lan; Gröters, Sibylle; Landsiedel, Robert; Donaghey, Thomas C; Brain, Joseph D; Wohlleben, Wendel; Molina, Ramon M

2014-10-21

8

Nickel hydroxide precipitation from aqueous sulfate media  

NASA Astrophysics Data System (ADS)

Hydrometallurgical processing of laterite ores constitutes a major industrial and R&D activity in extractive metallurgy. In some of the process flowsheets, nickel hydroxide precipitation is incorporated. For these operations, the optimization of nickel hydroxide precipitation is important to assure efficiency and product quality. The main objective of this investigation was to study and improve the precipitation characteristics of Ni(OH)2 in a sulfate system using supersaturation controlled precipitation.

Sist, Cinziana; Demopoulos, George P.

2003-08-01

9

Precipitation of Calcium, Magnesium, Strontium and Barium in Tissues of Four Acacia Species (Leguminosae: Mimosoideae)  

PubMed Central

Precipitation of calcium in plants is common. There are abundant studies on the uptake and content of magnesium, strontium and barium, which have similar chemical properties to calcium, in comparison with those of calcium in plants, but studies on co-precipitation of these elements with calcium in plants are rare. In this study, we compared morphologies, distributional patterns, and elemental compositions of crystals in tissues of four Acacia species grown in the field as well as in the glasshouse. A comparison was also made of field-grown plants and glasshouse-grown plants, and of phyllodes of different ages for each species. Crystals of various morphologies and distributional patterns were observed in the four Acacia species studied. Magnesium, strontium and barium were precipitated together with calcium, mainly in phyllodes of the four Acacia species, and sometimes in branchlets and primary roots. These elements were most likely precipitated in forms of oxalate and sulfate in various tissues, including epidermis, mesophyll, parenchyma, sclerenchyma (fibre cells), pith, pith ray and cortex. In most cases, precipitation of calcium, magnesium, strontium and barium was biologically induced, and elements precipitated differed between soil types, plant species, and tissues within an individual plant; the precipitation was also related to tissue age. Formation of crystals containing these elements might play a role in regulating and detoxifying these elements in plants, and protecting the plants against herbivory. PMID:22848528

He, Honghua; Bleby, Timothy M.; Veneklaas, Erik J.; Lambers, Hans; Kuo, John

2012-01-01

10

Molecular modeling of phosphonate molecules onto barium sulfate terraced surfaces.  

PubMed

The adsorption of phosphonate molecules onto mineral surfaces is of interest due to their use as scale inhibitors. Molecular modeling is an important tool that can aid the fundamental understanding of how these inhibitors operate. This paper presents an empirical molecular mechanics study of the adsorption of a series of straight chain phosphonate molecules onto barium sulfate. It has been found that inhibition can be predicted for this straight chain series of molecules, which differ by the number of phosphonate groups present as well as by the chain length. Even more importantly, the modeling results can predict which faces will be preferred, and this has been verified by scanning and transmission electron microscopy on the resultant barite particles. It has been found that, in general, lattice matching results in the lowest replacement energy for all of the organic molecules investigated. The agreement between the experiment and the model confirms that the dominant mechanism of interaction for the additives on barium sulfate is via the deprotonated phosphonate groups with the barium ions on the surface. PMID:16599519

Jones, Franca; Richmond, William R; Rohl, Andrew L

2006-04-13

11

Preparation of Nanoparticles of Barium Ferrite from Precipitation in Microemulsions  

Microsoft Academic Search

Magnetic nanoparticles of barium ferrite (BaFe12O19) have been synthesized using a microemulsion mediated process. The aqueous cores of water-in-oil microemulsions were used as constrained microreactors for the precipitation of precursor carbonate and hydroxide particles. These precursors were then calcined at 925°C for 12?h, during which time they were transformed to the hexagonal ferrite. The pH of reaction was varied between

B. J. Palla; D. O. Shah; P. Garcia-Casillas; J. Matutes-Aquino

1999-01-01

12

Comparison of the reflectance characteristics of polytetrafluoroethylene and barium sulfate paints  

NASA Technical Reports Server (NTRS)

Preliminary results are presented of the directional reflectance measurements taken on two tetrafluorethylene (TFE) paints formulated with silicone binders. Both paints are found to be more Lambertian than barium sulfate paint and pressed powder, although the pigment to binder ratios for barium sulfate and TFE paints are about 133 and 3.3 to 1, respectively. The TFE paints exhibit total visible reflectances above 90 percent and offer surfaces that are not significantly affected by water.

Butner, C. L.; Schutt, J. B.; Shai, M. C.

1984-01-01

13

The MSXX Force Field for the Barium Sulfate-Water Interface Yun Hee Jang,, Xiao Yan Chang, Mario Blanco, Sungu Hwang,, Yongchun Tang,  

E-print Network

The MSXX Force Field for the Barium Sulfate-Water Interface Yun Hee Jang,, Xiao Yan Chang, Mario, 2001; In Final Form: April 3, 2002 A new force field (MSXX FF) was developed for barium sulfate (BaSO4

Goddard III, William A.

14

IMAGING DIAGNOSIS-DUODENOBILIARY REFLUX OF BARIUM SULFATE DURING ESOPHAGOGASTROGRAPHY IN A DOG.  

PubMed

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. PMID:25066011

Shaikh, Layla; Sharma, Ajay; Secrest, Scott

2014-07-26

15

Improvement of the magnetic properties of barium hexaferrite nanopowders using modified co-precipitation method  

Microsoft Academic Search

Barium hexaferrite BaFe12O19 powders have been synthesized using the modified co-precipitation method. Modification was performed via the ultrasonication of the precipitated precursors at room temperature for 1h and the additions of the 2% KNO3, surface active agents and oxalic acid. The results revealed that single phase magnetic barium hexaferrite was formed at a low annealing temperature of 800°C for 2h

M. M. Rashad; I. A. Ibrahim

2011-01-01

16

SOURCE ASSESSMENT: MAJOR BARIUM CHEMICALS  

EPA Science Inventory

This report summarizes data on air emissions from the production of major barium chemicals. Compounds studied include barium sulfide, barium carbonate, barium chloride, barium hydroxide, and barium sulfate. In order to evaluate potential environmental effects the source severity,...

17

Microstructure and hysteresis curves of the barium hexaferrite from co-precipitation by organic agent  

NASA Astrophysics Data System (ADS)

This work correlates the magnetic hysteresis curves to the microstructure of the sintered polycrystalline barium hexaferrite discs produced from co-precipitated barium and iron citrates. Citric acid was used as the organic precipitating agent. Thermogravimetric and differential thermal analyses were performed on the co-precipitated product in order to guide its calcination into barium hexaferrite crystals, which was confirmed by means of the X-ray fluorescence and X-ray diffraction. After that, the hexaferrite powder was pressed in a steel die and submitted to firing in air at various temperatures. The final ceramic pieces were characterized by means of scanning electron microscopy and magnetic hysteresis grapher. The obtained results indicate a strong effect of the firing temperature on the microstructure, which in turn affected the magnetic hysteresis curve.

Ogasawara, T.; Oliveira, M. A. S.

2000-07-01

18

Preparation of nanosized barium zirconate powder by thermal decomposition of urea in an aqueous solution containing barium and zirconium, and by calcination of the precipitate  

Microsoft Academic Search

The synthesis of barium zirconate was initiated by urea induced homogeneous precipitation followed by a “low temperature” thermal treatment. The kinetic of the reaction and the optimum urea\\/cation ratio have been determined by means of X-ray diffraction and Inductive Coupled Plasma analyses. It has been demonstrated that an amorphous zirconium hydrated oxide starts to precipitate followed by the precipitation of

F. Boschini; B. Robertz; A. Rulmont; R. Cloots

2003-01-01

19

EPR dosimetric properties of nano-barium sulfate  

NASA Astrophysics Data System (ADS)

Nano/micro BaSO4 were prepared through the co-precipitation method to measure ionizing radiation doses using electron paramagnetic resonance (EPR). The nano-BaSO4 sample was characterized using X-ray diffraction (XRD), and transmission electron microscopy (TEM) techniques. The dose response and fading properties of nano- and micro-phase BaSO4 were compared in EPR spectra. The prepared nano- and micro-BaSO4 samples have the same hole and electron centers, which may be attributed to SO4- and SO3-, respectively. The dosimetric signals for prepared nano- and micro-BaSO4 have spectroscopic splitting factor (g) with values 2.0025±0.0006 and 2.0027±0.0006, respectively. The nanocrystalline sample has a linear ?-ray dose response over the range 0.4 Gy-1 kGy. The performance parameters which including detection limit and critical level calculated from weighted and unweighted least-squares fitting. The sensitivity of nano-BaSO4 to ?-ray is one and a half times more than alanine. The lifetime and activation energy for nano-BaSO4 were estimated by conducting a thermal stability study, and were 5.7±1.1×104 years and 0.73±0.14 eV, respectively. The combined and expanded uncertainties accompanying measurements were ±3.89% and ±7.78%, respectively.

Aboelezz, E.; Hassan, G. M.; Sharaf, M. A.; El-Khodary, A.

2015-01-01

20

Reactions of calcium orthosilicate and barium zirconate with oxides and sulfates of various elements  

NASA Technical Reports Server (NTRS)

Calcium orthosilicate and barium zirconate were evaluated as the insulation layer of thermal barrier coatings for air cooled gas turbine components. Their reactions with various oxides and sulfates were studied at 1100 C and 1300 C for times ranging up to 400 and 200 hours, respectively. These oxides and sulfates represent potential impurities or additives in gas turbine fuels and in turbine combustion air, as well as elements of potential bond coat alloys. The phase compositions of the reaction products were determined by X-ray diffraction analysis. BaZrO3 and 2CaO-SiO2 both reacted with P2O5, V2O5, Cr2O3, Al2O3, and SiO2. In addition, 2CaO-SiO2 reacted with Na2O, BaO, MgO, and CoO and BaZrO3 reacted with Fe2O3.

Zaplatynsky, I.

1979-01-01

21

Aqueous hafnium sulfate chemistry: structures of crystalline precipitates.  

PubMed

Crystalline precipitates resulting from the hydrolysis and subsequent condensation of Hf(IV) aqueous acidic solutions at 60-95 °C are examined and compared. By varying the concentrations of the acid and sulfate source, a variety of complex hafnium-oxo-hydroxo-sulfate clusters are isolated and structures accessed. Four novel compounds were discovered, while the structures of two known compounds, an 18-mer and a planar hexamer, were updated. In total, the compounds described herein each contain one of four cluster architectures: 18-mer, 11-mer, nonamer, and planar hexamer. In addition, one compound contains small amounts of 19-mers together with 18-mers. As well as examining the individual structure of each complex cluster, we relate them to one another, as well as to the dense phases of HfO2, to gain an understanding of their formation and stability. Finally, the solution conditions under which each cluster forms are identified by plotting the crystallization regions of each cluster against acidity and sulfate concentration. Most clusters form under slightly acidic conditions, in decreasing size as the sulfate concentration is raised. The flat hexamer is the single exception; it appears to require more acidic solutions. The degree of hydroxo- versus oxo-bridges with changing solution conditions is assessed within the broader context of the condensates. Of specific interest is the identification of these products as they relate to the use of hydrolysis reactions in designing new materials. PMID:25299984

Kalaji, Ali; Soderholm, L

2014-10-20

22

A Simple Method Based on the Application of a CCD Camera as a Sensor to Detect Low Concentrations of Barium Sulfate in Suspension  

PubMed Central

The development of a simple, rapid and low cost method based on video image analysis and aimed at the detection of low concentrations of precipitated barium sulfate is described. The proposed system is basically composed of a webcam with a CCD sensor and a conventional dichroic lamp. For this purpose, software for processing and analyzing the digital images based on the RGB (Red, Green and Blue) color system was developed. The proposed method had shown very good repeatability and linearity and also presented higher sensitivity than the standard turbidimetric method. The developed method is presented as a simple alternative for future applications in the study of precipitations of inorganic salts and also for detecting the crystallization of organic compounds. PMID:22346607

de Sena, Rodrigo Caciano; Soares, Matheus; Pereira, Maria Luiza Oliveira; da Silva, Rogério Cruz Domingues; do Rosário, Francisca Ferreira; da Silva, Joao Francisco Cajaiba

2011-01-01

23

Quantitative Analysis of Sulfate in Water by Indirect EDTA Titration  

ERIC Educational Resources Information Center

The determination of sulfate concentration in water by indirect EDTA titration is an instructive experiment that is easily implemented in an analytical chemistry laboratory course. A water sample is treated with excess barium chloride to precipitate sulfate ions as BaSO[subscript 4](s). The unprecipitated barium ions are then titrated with EDTA.…

Belle-Oudry, Deirdre

2008-01-01

24

Improvement of the magnetic properties of barium hexaferrite nanopowders using modified co-precipitation method  

NASA Astrophysics Data System (ADS)

Barium hexaferrite BaFe12O19 powders have been synthesized using the modified co-precipitation method. Modification was performed via the ultrasonication of the precipitated precursors at room temperature for 1 h and the additions of the 2% KNO3, surface active agents and oxalic acid. The results revealed that single phase magnetic barium hexaferrite was formed at a low annealing temperature of 800 °C for 2 h with the Fe3+/Ba2+ molar ratio 8. The microstructure of the powders appeared as a homogeneous hexagonal platelet-like structure using 2% KNO3 as the crystal modifier. A saturation magnetization (60.4 emu/g) was achieved for the BaFe12O19 phase formed at 1000 °C for 2 h with Fe3+/Ba2+ molar ratio 8 using 5 M NaOH solution at pH 10 in the presence of 2% KNO3. Moreover, the saturation magnetization was 52.2 emu/g for the precipitated precursor at Fe3+/Ba2+ molar ratio 12 in was achieved for the precipitated precursor ultrasonicated for 1 h and then annealed at 1200 °C for 2 h. Coercivities from 956.9 to 4558 Oe were obtained at different synthesis conditions.

Rashad, M. M.; Ibrahim, I. A.

2011-08-01

25

Role of intermediate milling in the processing of nano-size particles of barium hexaferrite via co-precipitation method  

Microsoft Academic Search

Nano-crystalline particles of barium hexaferrite (BaFe12O19) have been prepared by a co-precipitation\\/mechanical milling technique using aqueous solutions of iron and barium chlorides with a Fe\\/Ba molar ratio of 11 and subsequent mechanical milling with a high energy planetary mill. The thermal properties, phase composition and morphology of the products were studied. DTA\\/TGA results confirmed by those obtained from XRD indicated

K. Sheikhi Moghaddam; A. Ataie

2006-01-01

26

Sulfate-reducing bacteria release barium and radium from naturally occurring radioactive material in oil-field barite  

USGS Publications Warehouse

Scale and sludge deposits formed during oil production can contain elevated levels of Ra, often coprecipitated with barium sulfate (barite). The potential for sulfate-reducing bacteria to release 226 Ra and Ba (a Ra analog) from oil-field barite was evaluated. The concentration of dissolved Ba increased when samples containing pipe scale, tank sludge, or oil-field brine pond sediment were incubated with sulfate-reducing bacteria Desulfovibrio sp., Str LZKI, isolated from an oil-field brine pond. However, Ba release was not stoichiometric with sulfide production in oil-field samples, and <0.1% of the Ba was released. Potential for the release of 226Ra was demonstrated, and the 226 Ra release associated with sulfate-reducing activity was predictable from the amount of Ba released. As with Ba, only a fraction of the 226Ra expected from the amount of sulfide produced was released, and most of the Ra remained associated with the solid material.

Phillips, E.J.P.; Landa, E.R.; Kraemer, T.; Zielinski, R.

2001-01-01

27

Precipitation of barium flouride microcrystals from electrolytic solutions: The influence of the composition of the precipitating solutions  

NASA Astrophysics Data System (ADS)

The composition, shape and size of the particles obtained by precipitation in aqueous solutions of various barium salts (chloride, nitrate and acetate) with various fluorides (ammonium, sodium and hydrogen) have been studied by X-ray powder diffraction analysis and scanning electron microscopy. From Ba(NO 3) 2 in combination with NH 4F or NaF and from Ba(C 2H 3O 2) 2 in combination with NH 4F, NaF or HF, precipitates of pure cubic-BaF 2 (?-BaF 2) are obtained. The shape and size of ?-BaF 2 particles depend on the combination of the compounds used for the precipitation and their concentrations. It appears that only when (equal volumes of) solutions of Ba(NO 3) 2 (0.125 mol dm -3) or Ba(C 2H 3O 2) 2 (0.125 and 0.150 mol dm -3) and NH 4F (0.250 or 0.300 mol dm -3) are mixed particles are formed as more or less regular cubes with smooth faces. These crystals are suitable to be used in studies of the transport of ions from crystals to the solution and vice versa with the aid of radioactive tracers ("heterogeneous isotopic exchange" studies).

Kolar, Z.; Binsma, J. J. M.; Suboti?, B.

1984-02-01

28

Use of 24kHz ultrasound to improve sulfate precipitation from wastewater.  

PubMed

Elevated sulfate concentrations in industrial effluent can lead to a number of significant problems, the most serious of which is the corrosion of concrete sewers as a result of hydrogen sulfide induced biogenic sulfuric acid attack; hydrogen sulfide can also create odor nuisance problems. The most common treatment process for sulfate removal from wastewaters is to precipitate it as gypsum using lime addition. Nevertheless, meeting discharge consent limits for sulfate can often present practical challenges due to the solubility of gypsum and so there is a need to investigate technological solutions that might provide for more consistent sulfate removal. This paper reports on the application of ultrasound during the sulfate precipitation process. We show that with as little as 10s sonication at 24kHz, significant increases in the rate of sulfate precipitation are observed. Particle size analysis, pH profiles and SEM micrographs, suggest that the likely mode of action is disaggregation of the calcium hydroxide particles, giving a greater solid-liquid interface, thus resulting in a faster dissolution rate and more readily available calcium ions. A range of experimental variables are studied, including the duration and power of sonication, as well as initial sulfate concentration and the effect of changing the time at which sonication is applied. For both sonicated and non-sonicated samples, precipitation commences almost immediately that the lime is added and so induction time is not an issue in this system. PMID:25218769

Davies, Lisa A; Dargue, Andrew; Dean, John R; Deary, Michael E

2015-03-01

29

SEMI-BATCH PRECIPITATION OF CALCIUM SULFATE DIHYDRATE FROM CALCITE AND SULFURIC ACID  

E-print Network

SEMI-BATCH PRECIPITATION OF CALCIUM SULFATE DIHYDRATE FROM CALCITE AND SULFURIC ACID Frédéric BARD1 a calcite suspension to a sulfuric acid solution from industrial waste. The morphology of the precipitated, sulfuric acid, industrial waste. 1. INTRODUCTION Gypsum is a mineral compound of first importance

Paris-Sud XI, Université de

30

Effect of the solution ionic composition upon the precipitation kinetics and self-organization processes in basic iron sulfate precipitates  

Microsoft Academic Search

A possibility is shown for the control over self-organization processes in multi-phase precipitates at oxidative-hydrolytic precipitation of Fe (III) ions (oxidized from Fe(II) state) from sulfate solutions. A decrease in the degree of the system non-equilibration and precise optimization of the onset conditions afforded the elimination of the concentration self-oscillations, estimation of the process kinetic parameters and obtaining basic iron

N. M. Sergeeva; V. G. Korsakov; Y. Nakanishi; S. V. Mjakin; H. Kominami

2005-01-01

31

Bioabsorbable bone fixation plates for X-ray imaging diagnosis by a radiopaque layer of barium sulfate and poly(lactic-co-glycolic acid).  

PubMed

Bone fixation systems made of biodegradable polymers are radiolucent, making post-operative diagnosis with X-ray imaging a challenge. In this study, to allow X-ray visibility, we separately prepared a radiopaque layer and attached it to a bioabsorbable bone plate approved for clinical use (Inion, Finland). We employed barium sulfate as a radiopaque material due to the high X-ray attenuation coefficient of barium (2.196 cm(2) /g). The radiopaque layer was composed of a fine powder of barium sulfate bound to a biodegradable material, poly(lactic-co-glycolic acid) (PLGA), to allow layer degradation similar to the original Inion bone plate. In this study, we varied the mass ratio of barium sulfate and PLGA in the layer between 3:1 w/w and 10:1 w/w to modulate the degree and longevity of X-ray visibility. All radiopaque plates herein were visible via X-ray, both in vitro and in vivo, for up to 40 days. For all layer types, the radio-opacity decreased with time due to the swelling and degradation of PLGA, and the change in the layer shape was more apparent for layers with a higher PLGA content. The radiopaque plates released, at most, 0.5 mg of barium sulfate every 2 days in a simulated in vitro environment, which did not appear to affect the cytotoxicity. The radiopaque plates also exhibited good biocompatibility, similar to that of the Inion plate. Therefore, we concluded that the barium sulfate-based, biodegradable plate prepared in this work has the potential to be used as a fixation device with both X-ray visibility and biocompatibility. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2014. PMID:24964903

Choi, Sung Yoon; Hur, Woojune; Kim, Byeung Kyu; Shasteen, Catherine; Kim, Myung Hun; Choi, La Mee; Lee, Seung Ho; Park, Chun Gwon; Park, Min; Min, Hye Sook; Kim, Sukwha; Choi, Tae Hyun; Choy, Young Bin

2014-06-26

32

BARIUM BIOAVAILABILITY AS THE CHLORIDE, SULFATE, OR CARBONATE SALT IN THE RAT  

EPA Science Inventory

This study was conducted to determine how the bioavailability of a low concentration of barium (Ba) in drinking water is affected by anion speciation. Male Sprague Dawley rats weighing 250-300 grams were maintained on a diet of less than 1 mg Ba/kg of food for at least 1 month pr...

33

Effect of dispersant on preparation of barium-strontium titanate powders through oxalate co-precipitation method  

SciTech Connect

The quantitative precipitation of barium-strontium titanyl oxalate: (Ba{sub 0.6}Sr{sub 0.4}TiO(C{sub 2}O{sub 4}){sub 2}.4H{sub 2}O, BSTO) precursor powders were successfully prepared through oxalate co-precipitation method. The pyrolysis of BSTO at 800 deg. C/4 h produced the barium-strontium titanate (Ba{sub 0.6}Sr{sub 0.4}TiO{sub 3}, BST) powders. Two kinds of dispersants namely ammonium salt of poly mathacrylic acid (PMAA-NH{sub 4}) and polyethylene glycol (PEG) were added respectively during the co-precipitation procedure. The powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), etc. Experimental results show that the addition of the dispersants reduced the productive rate of BST powders. The BSTO and BST powders obtained by aforementioned technique without dispersants were homogeneous with quasi-orbicular morphology. The particles grew into spindle shape with the effect of PEG. The morphology homogeneity was broke with small grains as well as large agglomerated particles concurrent when PMAA-NH{sub 4} was added. The mechanism of the effect of the two dispersants was investigated in detail.

Li Mingli [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Weijin Road 92, Tianjin 300072 (China)], E-mail: lml@tju.edu.cn; Xu Mingxia [School of Materials Science and Engineering, Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Weijin Road 92, Tianjin 300072 (China)

2009-04-02

34

Presence of sulfate does not inhibit low-temperature dolomite precipitation  

NASA Astrophysics Data System (ADS)

The hypothesis that sulfate inhibits dolomite formation evolved from geochemical studies of porewaters from deep-sea sedimentary sequences and has been tested with hydrothermal experiments. We examined the sulfate inhibition factor using aerobic culture experiments with Virgibacillus marismortui and Halomonas meridiana, two moderately halophilic aerobic bacteria, which metabolize independent of sulfate concentration. The culture experiments were conducted at 25 and 35 °C using variable SO 42- concentrations (0, 14, 28 and 56 mM) and demonstrate that halophilic aerobic bacteria mediate direct precipitation of dolomite with or without SO 42- in the culture media which simulate dolomite occurrences commonly found under the Earth's surface conditions. Hence, we report that the presence of sulfate does not inhibit dolomite precipitation. Further, we hypothesize that, if sedimentary dolomite is a direct precipitate, as in our low-temperature culture experiments, the kinetic factors involved are likely to be quite different from those governing a dolomite replacement reaction, such as in hydrothermal experiments. Consequently, the occurrence and, presumably, growth of dolomite in SO 42--rich aerobic cultures may shed new light on the long-standing Dolomite Problem.

Sánchez-Román, Mónica; McKenzie, Judith A.; de Luca Rebello Wagener, Angela; Rivadeneyra, Maria A.; Vasconcelos, Crisógono

2009-07-01

35

COMPARISON OF WET CHEMICAL AND INSTRUMENTAL METHODS FOR MEASURING AIRBORNE SULFATE  

EPA Science Inventory

Four techniques for determination of water soluble sulfate in atmospheric samples were compared including the barium sulfate turbidimetric method, the Brosset (barium-Thorin) method, the automated barium-methylthymol blue procedure and a microchemical (barium-dinitro-sulfanazo II...

36

Optimization of isopropanol and ammonium sulfate precipitation steps in the purification of plasmid DNA.  

PubMed

Large-scale processes used to manufacture grams of plasmid DNA (pDNA) should be cGMP compliant, economically feasible, and environmentally friendly. Alcohol and salt precipitation techniques are frequently used in plasmid DNA (pDNA) downstream processing, as concentration and prepurification steps, respectively. This work describes a study of a standard 2-propanol (IsopOH; 0.7 v/v) and ammonium sulfate (AS; 2.5 M) precipitation. When inserted in a full process, this tandem precipitation scheme represents a high economic and environmental impact due to the large amounts of the two precipitant agents and their environmental relevance. Thus, major goals of the study were the minimization of precipitants and the selection of the best operating conditions for high pDNA recovery and purity. The pDNA concentration in the starting Escherichia coli alkaline lysate strongly affected the efficiency of IsopOH precipitation as a concentration step. The results showed that although an IsopOH concentration of at least 0.6 (v/v) was required to maximize recovery when using lysates with less than 80 microg pDNA/mL, concentrations as low as 0.4 v/v could be used with more concentrated lysates (170 microg pDNA/mL). Following resuspension of pDNA pellets generated by 0.6 v/v IsopOH, precipitation at 4 degrees C with 2.4 M AS consistently resulted in recoveries higher than 80% and in removal of more than 90% of the impurities (essentially RNA). An experimental design further indicated that AS concentrations could be reduced down to 2.0 M, resulting in an acceptable purity (21-23%) without compromising recovery (84-86%). Plasmid recovery and purity after the sequential IsopOH/AS precipitation could be further improved by increasing the concentration factor (CF) upon IsopOH precipitation from 2 up to 25. Under these conditions, IsopOH and AS concentrations of 0.60 v/v and 1.6 M resulted in high recovery (approximately 100%) and purity (32%). In conclusion, it is possible to reduce substantially the mass of precipitation agents used without affecting recovery, if a small concession is made regarding purity. This directly translates into an improvement of the process economics and in a reduction of the environmental impact of the process. PMID:16889396

Freitas, S S; Santos, J A L; Prazeres, D M F

2006-01-01

37

Precipitation method for barium metaborate (BaB{sub 2}O{sub 4}) synthesis from borax solution  

SciTech Connect

In this study, barium metaborate (BaB{sub 2}O{sub 4}, BMB) synthesis from the borax solution was carried out. BMB currently is used in production of ceramic glazes, luminophors, oxide cathodes as well as additives to pigments for aqueous emulsion paints and also ??BaB{sub 2}O{sub 4} single crystals are the best candidate for fabrication of solid-state UV lasers operating at a wavelength of 200 nm due to excellent nonlinear optical properties. In the present study, synthesis was carried out from the borax solution (Na{sub 2}B{sub 4}O{sub 7?}10H{sub 2}O, BDH) and barium chloride (BaCI{sub 2?}2H{sub 2}O, Ba) in the glass-batch reactor with stirring. The effect of, times (5-15 min), molar ratio [stoich.ration (1.0:2.0), 1.25:2.0, 1.5:2.0, 2.5:2:0, 3.0:2.0, 3.5:2.0,4.0:2.0, 5.0:2.0] and also crystallization time (2-6 hour) on the BMB yield (%) was investigated at 80 °C reaction temperature. It is found that, BMB precipitation synthesis with 90 % yield can be performed from 0.50 molar ration (BDH:Ba), under 80 °C, 15 minute, and 6 hours crystallization time. The structural properties of BMB powders were characterized by using XRD, FT-IR and DTA-TG instrumental analysis technique.

Ak?ener, Eymen; Figen, Aysel Kantürk; Pi?kin, Sabriye [Yildiz Technical University, Chem. Eng. Dept., Davutpasa Campus, 34210, Istanbul (Turkey)

2013-12-16

38

Three-dimensional current flow and particle precipitation in a westward travelling surge \\/observed during the barium-GEOS rocket experiment  

Microsoft Academic Search

During the Barium-GEOS rocket experiment on September 24, 1979 the passage of a westward travelling surge (WTS) was observed over Scandinavia. Extended instrument networks in that area, viz., the Scandinavian Magnetometer Array, the STARE radars, all-sky cameras, and riometers, allowed simultaneous observation of the two-dimensional character of magnetic and electric field disturbances and particle precipitation associated with the auroral feature.

H. J. Opgenoorth; R. J. Pellinen; Wolfgang Baumjohann; Erling Nielsen; Göran Marklund; Lars Eliasson

1983-01-01

39

Influence of semi-batch operation on the precipitation of natrojarosite particles from sulfate solutions  

NASA Astrophysics Data System (ADS)

The precipitation of natrojarosite from iron sodium sulfate solutions has been investigated at temperatures close to the atmospheric boiling point, in batch and semi-batch conditions. Semi-batch conditions make it possible to maintain a weaker iron concentration in the stirred reactor, leading to lower supersaturations, closer to those in continuous and possibly seeded MSMPRs or tanks—in series units. In these reactors, primary and secondary nucleations are few, allowing the growth of pure mono-crystalline particles of controlled size and size dispersion. Both modi operandi lead to agglomerates made of crystals of cubic habit. The surface of cauliflower-like particles from the batch modus operandi displays overlaying crystals, of size between 100 and 400 nm. The particles from the semi-batch mode, with moderate iron addition, are rougher and show bigger intergrown constitutive crystals of size up to a few microns, which denotes lesser secondary nucleation and more growth. A model is developed to characterize iron(III) and sulfate speciation with non-ideal behavior in the mother solution. It is used to compare the variations of supersaturation in the reactor between the batch and the semi-batch conditions. During the first 500 min, the supersaturation resulting from a moderate addition of iron is 10,000-10 times lower than during batch kinetics, which agrees with the reduction of secondary nucleation suggested by scanning electron micrographs. The semi-batch technique, which can be combined with the addition of support particles, is worth further work, aiming to reduce secondary nucleation and to determine the crystallite growth rate expression of natrojarosite as a function of supersaturation, using the model of solution developed in this work.

Sandré, Anne-Laure; Gaunand, Alain

2012-03-01

40

Determination of HDL 2 cholesterol by precipitation with dextran sulfate and magnesium chloride: Establishing optimal conditions for rat plasma  

Microsoft Academic Search

Optimal conditions for analyzing HDL2 cholesterol in small amounts of rat plasma have been studied using different concentrations of dextran sulfate and MgCl2 to precipitate lipoproteins containing apolipoprotein B and\\/or apo E. When the MgCl2 level was 91 mM, the supernate cholesterol was rather constant at a level of about 50–60% of the total plasma cholesterol\\u000a concentration. Immunochemical determination of

Linnea Sjoblom; Anders Eklund

1989-01-01

41

Radiographic anatomy and barium sulfate contrast transit time of the gastrointestinal tract of bearded dragons (Pogona vitticeps).  

PubMed

The positive contrast gastrointestinal study is a common non-invasive diagnostic technique that does not require anesthesia and enables good visualization of the digestive tract. Radiographic anatomy and reference intervals for gastrointestinal contrast transit time in inland bearded dragons (Pogona vitticeps) were established using seven animals administered 15 ml/kg of a 35% w/v suspension of barium by esophageal gavage. Dorso-ventral and lateral radiographic views were performed at 0, 15, 30 min, 1, 2, 4, 6, 8, 12 h, and then every 12 h up to 96 h after barium administration. Gastric emptying was complete at a median time of 10 h (range 4-24 h). Median jejunum and small intestinal emptying times were 1 h (range 30 min-2 h) and 29 h (range 24-48 h), respectively. Median transit time for cecum was 10 h (range 8-12 h). Median time for contrast to reach the colon was 31 h (range 12-72 h) after administration. Results were compared to those obtained in other reptilian species. This technique appeared safe in fasted bearded dragons and would be clinically applicable in other lizard species. PMID:24945023

Grosset, Claire; Daniaux, Lise; Guzman, David Sanchez-Migallon; Weber, Ernest Scott; Zwingenberger, Allison; Paul-Murphy, Joanne

2014-01-01

42

Evidence for Aqueously Precipitated Sulfates in Northeast Meridiani Using THEMIS and TES Data  

NASA Technical Reports Server (NTRS)

Recently aqueously deposited sulfate-rich bedrock was found at the MER-B Meridiani landing site [1]. Additional sulfate was observed from orbit by the Mars Express OMEGA instrument [2]. In this work, I present midinfrared spectral evidence (using THEMIS and TES) for sulfate in and around a channel deposit that lies to the northeast of the hematite- strewn plains of Meridiani at approx.2degN, 1degW (Fig. 1).

Lane, Melissa D.

2005-01-01

43

Biodegradation of BTEX and Other Petroleum Hydrocarbons by Enhanced and Controlled Sulfate Reduction  

SciTech Connect

High concentrations of sulfide in the groundwater at a field site near South Lovedale, OK, were inhibiting sulfate reducing bacteria (SRB) that are known to degrade contaminants including benzene, toluene, ethylbenzene, and m+p-xylenes (BTEX). Microcosms were established in the laboratory using groundwater and sediment collected from the field site and amended with various nutrient, substrate, and inhibitor treatments. All microcosms were initially amended with FeCl{sub 2} to induce FeS precipitation and, thereby, reduce sulfide concentrations. Complete removal of BTEX was observed within 39 days in treatments with various combinations of nutrient and substrate amendments. Results indicate that elevated concentration of sulfide is a limiting factor to BTEX biodegradation at this site, and that treating the groundwater with FeCl{sub 2} is an effective remedy to facilitate and enhance BTEX degradation by the indigenous SRB population. On another site in Moore, OK, studies were conducted to investigate barium in the groundwater. BTEX biodegradation by SRB is suspected to mobilize barium from its precipitants in groundwater. Data from microcosms demonstrated instantaneous precipitation of barium when sulfate was added; however, barium was detected redissolving for a short period and precipitating eventually, when active sulfate reduction was occurring and BTEX was degraded through the process. SEM elemental spectra of the evolved show that sulfur was not present, which may exclude BaSO{sub 4} and BaS as a possible precipitates. The XRD analysis suggests that barium probably ended in BaS complexing with other amorphous species. Results from this study suggest that SRB may be able to use the sulfate from barite (BaSO{sub 4}) as an electron acceptor, resulting in the release of free barium ions (Ba{sup 2+}), and re-precipitate it in BaS, which exposes more toxicity to human and ecological health.

Song Jin

2007-07-01

44

BACKGROUND CONCENTRATION OF SULFATE IN PRECIPITATION ALONG WITH WEST COAST OF NORTH AMERICA  

EPA Science Inventory

The pH is not sufficient to characterize the acidity of precipitation, but rather its acid-base components must be described. he chemistry of natural emission sources as well as the mechanisms of precipitation formation are key factors in determining the chemistry of precipitatio...

45

ACID PRECIPITATION: EFFECTS OF SULFUR DIOXIDE AND SULFATE AEROSOL PARTICLES ON HUMAN HEALTH  

EPA Science Inventory

While human health impairment has been attributed to pollution by sulfur dioxide (SO2), data from inhalation studies in animals show that its oxidation products are more irritating. Population surveys in which suspended sulfate was a co-variant suggest that certain health paramet...

46

Barium Peritonitis in Small Animals  

PubMed Central

ABSTRACT Barium peritonitis is extremely rare, but is difficult to treat and may be life-threatening. Barium suspension leakage from the gastrointestinal tract into the abdominal cavity has a time-dependent and synergistically deleterious effect in patients who have generalized bacterial peritonitis. The severity of barium peritonitis is dependent on the quantity of barium in the abdominal cavity. Barium sulfate leakage results in hypovolemia and hypoproteinemia by worsening the exudation of extracellular fluid and albumin. Abdominal fluid analysis is a useful and efficient method to diagnose barium peritonitis. Serial radiographs may not be a reliable or timely diagnostic technique. Initial aggressive fluid resuscitation and empirical broad-spectrum antibiotic treatment should be instituted promptly, followed quickly by celiotomy. During exploratory surgical intervention, copious irrigation and direct wiping with gauze are employed to remove as much barium as possible. Omentectomy should be considered when needed to expedite barium removal. Despite aggressive medical and surgical treatments, postoperative prognosis is guarded to poor due to complications, such as acute vascular shock, sepsis, diffuse peritonitis, hypoproteninemia, electrolyte imbalance, cardiac arrest, small bowel obstruction related to progression of granulomas and adhesions in the abdominal cavity. Therefore, intensive postoperative monitoring and prompt intervention are necessary to maximize chances for a positive outcome. For those that do survive, small bowel obstruction is a potential consequence due to progression of abdominal adhesions. PMID:24430662

KO, Jae Jin; MANN, F. A. (Tony)

2014-01-01

47

Barium peritonitis in small animals.  

PubMed

Barium peritonitis is extremely rare, but is difficult to treat and may be life-threatening. Barium suspension leakage from the gastrointestinal tract into the abdominal cavity has a time-dependent and synergistically deleterious effect in patients who have generalized bacterial peritonitis. The severity of barium peritonitis is dependent on the quantity of barium in the abdominal cavity. Barium sulfate leakage results in hypovolemia and hypoproteinemia by worsening the exudation of extracellular fluid and albumin. Abdominal fluid analysis is a useful and efficient method to diagnose barium peritonitis. Serial radiographs may not be a reliable or timely diagnostic technique. Initial aggressive fluid resuscitation and empirical broad-spectrum antibiotic treatment should be instituted promptly, followed quickly by celiotomy. During exploratory surgical intervention, copious irrigation and direct wiping with gauze are employed to remove as much barium as possible. Omentectomy should be considered when needed to expedite barium removal. Despite aggressive medical and surgical treatments, postoperative prognosis is guarded to poor due to complications, such as acute vascular shock, sepsis, diffuse peritonitis, hypoproteninemia, electrolyte imbalance, cardiac arrest, small bowel obstruction related to progression of granulomas and adhesions in the abdominal cavity. Therefore, intensive postoperative monitoring and prompt intervention are necessary to maximize chances for a positive outcome. For those that do survive, small bowel obstruction is a potential consequence due to progression of abdominal adhesions. PMID:24430662

Ko, Jae Jin; Mann, F A Tony

2014-05-01

48

Anthropogenic sulfate aerosol and the southward shift of tropical precipitation in the late 20th century  

NASA Astrophysics Data System (ADS)

In this paper, we demonstrate a global scale southward shift of the tropical rain belt during the latter half of the 20th century in observations and global climate models (GCMs). In rain gauge data, the southward shift maximizes in the 1980s and is associated with signals in Africa, Asia, and South America. A southward shift exists at a similar time in nearly all CMIP3 and CMIP5 historical simulations, and occurs on both land and ocean, although in most models the shifts are significantly less than in observations. Utilizing a theoretical framework based on atmospheric energetics, we perform an attribution of the zonal mean southward shift of precipitation across a large suite of CMIP3 and CMIP5 GCMs. Our results suggest that anthropogenic aerosol cooling of the Northern Hemisphere is the primary cause of the consistent southward shift across GCMs, although other processes affecting the atmospheric energy budget also contribute to the model-to-model spread.

Hwang, Yen-Ting; Frierson, Dargan M. W.; Kang, Sarah M.

2013-06-01

49

Precipitation  

NSDL National Science Digital Library

The representation describes precipitation. It includes a diagram of mountains, ocean, clouds and rain with an accompanying short explanation. Within the explanation the words rain, snow, hail, sleet and freezing rain are links to another screen with information and a photograph. The resource also includes a description of extremes (desert as compared with rainforest) and geographic variability of precipitation).

50

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

PubMed

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. PMID:23485244

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

2013-01-01

51

Selectivity in biomineralization of barium and strontium.  

PubMed

The desmid green alga Closterium moniliferum belongs to a small number of organisms that form barite (BaSO(4)) or celestite (SrSO(4)) biominerals. The ability to sequester Sr in the presence of an excess of Ca is of considerable interest for the remediation of (90)Sr from the environment and nuclear waste. While most cells dynamically regulate the concentration of the second messenger Ca(2+) in the cytosol and various organelles, transport proteins rarely discriminate strongly between Ca, Sr, and Ba. Herein, we investigate how these ions are trafficked in C. moniliferum and how precipitation of (Ba,Sr)SO(4) crystals occurs in the terminal vacuoles. Towards this goal, we simultaneously visualize intracellular dynamics of multiple elements using X-ray fluorescence microscopy (XFM) of cryo-fixed/freeze-dried samples. We correlate the resulting elemental maps with ultrastructural information gleaned from freeze-fracture cryo-SEM of frozen-hydrated cells and use micro X-ray absorption near edge structure (micro-XANES) to determine sulfur speciation. We find that the kinetics of Sr uptake and efflux depend on external Ca concentrations, and Sr, Ba, and Ca show similar intracellular localization. A highly ion-selective cross-membrane transport step is not evident. Based on elevated levels of sulfate detected in the terminal vacuoles, we propose a "sulfate trap" model, where the presence of dissolved barium leads to preferential precipitation of (Ba,Sr)SO(4) due to its low solubility relative to SrSO(4) and CaSO(4). Engineering the sulfate concentration in the vacuole may thus be the most direct way to increase the Sr sequestered per cell, an important consideration in using desmids for phytoremediation of (90)Sr. PMID:21871966

Krejci, Minna R; Wasserman, Brian; Finney, Lydia; McNulty, Ian; Legnini, Daniel; Vogt, Stefan; Joester, Derk

2011-11-01

52

Prevention and control of sulfate scaling in the Namorado field, Campos Basin, Brazil  

SciTech Connect

Precipitation inhibitor squeeze treatments have been performed in the last 5 years in the Namorado field to avoid barium sulfate and strontium sulfate scaling in the producing tubing. This paper describes the laboratory tests conducted to select inhibitor and to simulate the squeeze operation in porous media. Based on these tests a polyacrylic acid product was used in the squeeze operations. The squeeze operation design is described as well as the strategy for analytical monitoring of the produced waters to select the wells with high precipitation potential for the prevention treatment. This paper describes the occurrence of spherical precipitated material (with morphology similar to ooids formed in natural environments) at the bottom of the well NA-C. The analysis of the ooids, associated with the production parameters, allowed the determination of the effectiveness of the squeeze treatment and the understanding of the precipitation mechanisms.

Bezerra, M.C.M.; Rosario, F.F. do; Khalil, C.N.; Milanez, P.V.A.; Souza, R.S. de [Cidade Univ., Rio de Janeiro (Brazil). Petrobras Research and Development Center

1996-08-01

53

Barite fronts in continental margin sediments: a new look at barium remobilization in the zone of sulfate reduction and formation of heavy barites in diagenetic fronts  

Microsoft Academic Search

Micro-crystalline barites recovered by deep-sea drilling from Site 684 on the Peru margin and Site 799 in the Japan Sea are highly enriched in the heavy sulfur isotope relative to seawater (?34S up to + 84%). This isotopic composition is consistent with remobilization of biogenic barite triggered by sulfate reduction, and subsequent reprecipitation as a diagenetic barite front. The high

M. E. Torres; H. J. Brumsack; G. Bohrmann; K. C. Emeis

1996-01-01

54

Magnetic and dielectric properties of barium titanate-coated barium ferrite  

Microsoft Academic Search

Flaky barium ferrite with hexagonal molecular structure was successfully prepared by reverse microemulsion method, and was coated with barium titanate through a coordination–precipitation technique. The prepared composite particles were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), vibrating sample magnetometry (VSM) and vector network analyzer. Barium ferrite nanoparticles are proved to be single magnetic

Chao Wang; Xijiang Han; Ping Xu; Xiaohong Wang; Xueai Li; Hongtao Zhao

2009-01-01

55

The effects of pH regulation upon the release of sulfate from ferric precipitates formed in acid mine drainage  

Microsoft Academic Search

`Batch experiments' (25:1 v:w) were used to test the effects of pH upon the release of SO?24 from ferric precipitates formed in acid mine drainage (AMD) in southeastern Kentucky. Analytical grade CaO [`quicklime'], Ca(OH)2 [hydrated lime] and CaCO3 [referred to as `limestone'] were used as alkalinity generating agents and were mixed with ferric precipitates composed of amorphous iron oxyhydroxides, jarosite

Seth Rose; W. Crawford Elliott

2000-01-01

56

Barium Enema Examination  

MedlinePLUS

Barium Enema Examination What you need to know about… A barium enema examination dem- onstrates your large bowel (colon). ... a diagnostically useful image. Prior to performing your barium enema examination, the radiographer will give you a ...

57

Akaganéite (?-FeOOH) precipitation in inland acid sulfate soils of south-western New South Wales (NSW), Australia  

NASA Astrophysics Data System (ADS)

The prevalence of sulphidic sediments in inland wetlands has been only recently recognized in many parts of the world, including Australia. The exposure of sulphidic sediments in these wetlands due to natural and human induced drying events has resulted in the oxidation of iron sulfide minerals, the formation of secondary iron minerals characteristic of acid sulfate soils and the release of highly acidic solutions. The objective of this study was to determine the mineralogy and morphology of sediments collected from the oxidized surface horizon (0-5 cm) of an inland acid sulfate soil located in south-western New South Wales (NSW), Australia. Random powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning transmission electron microscopy combined with energy dispersive X-ray spectroscopy (STEM-EDS) techniques were used to characterize the minerals present in these sediments. Akaganéite was identified as the major mineral phase in the sediments; K-jarosite was also determined in small amounts in some sediments. The XRD patterns of sequentially washed (E-pure® water-0.01 M HCl-0.01 M EDTA) sediment samples showed all akaganéite peaks; the Rietveld refinement of these patterns also revealed a predominance of akaganéite. The chemical analyses of the original and washed sediments using STEM-EDS clearly showed the presence of akaganéite as a pure mineral phase with an average Fe/Cl mole ratio of 6.7 and a structural formula of Fe 8O 8(OH) 6.8(Cl) 1.2. These findings show that the extreme saline-acidic solutions (pH ˜ 2, EC = 216 dS/m) at the Bottle Bend lagoon provide ideal conditions for the crystallization of this rarely forming mineral.

Bibi, Irshad; Singh, Balwant; Silvester, Ewen

2011-11-01

58

Thermal decomposition of (BaTi) citrates into barium titanate  

Microsoft Academic Search

From aqueous solutions of barium and titanium citrates two different (BaTi) citrate salts can be precipitated, depending on the pH of the solution. The ratio of barium to titanium in the salts is either 1 : 1 or 2 : 1. The thermal decomposition of the salts was investigated by means of DTA, TGA, infrared spectroscopy, and X-ray diffraction. At

D. Hennings; W. Mayr

1978-01-01

59

Emission spectrographic determination of barium in sea water using a cation exchange concentration procedure  

USGS Publications Warehouse

A concentration technique employing Dowex 50W cation exchange resin is described for the determination of barium in sea water. The separated barium is precipitated as fluoride together with calcium and strontium and measured by emission spectrographic analysis. The vertical distribution of barium in sea water has been measured in the Caribbean Sea and the Atlantic Ocean. The barium content varied between 7 and 23 ??g. per liter; in two profiles, the lowest concentrations were at a depth of about 1000 meters.

Szabo, B. J.; Joensuu, O.

1967-01-01

60

Microbial sulfate reduction within the Iheya North subseafloor hydrothermal system constrained by quadruple sulfur isotopes  

NASA Astrophysics Data System (ADS)

Subseafloor hydrothermal system may host active and abundant microbial community. Sulfate reduction may be one of the dominant microbial metabolisms among the subseafloor ecosystem. In order to demonstrate and quantify the potential sulfate reducing activity, we analyzed sulfur isotopes (32S/33S/34S/36S) of pore water sulfate extracted from core samples at the Iheya North hydrothermal system in the Okinawa drilled by CHIKYU, 2009 (IODP Leg 331). After drilling, core samples were divided into several sections. Then, pore water was extracted on board, and stored with cadmium chloride for fixing hydrogen sulfide. In our laboratory, the samples were first divided into sulfide precipitate and supernatant liquid by centrifugation. Then, dissolved sulfate was precipitated as BaSO4 by addition of barium chloride into the supernatant liquid. After weighing, the barium sulfate was converted into silver sulfide and subsequently sulfur hexafluoride, which was purified by GC and then introduced into mass spectrometer (MAT253) through newly developed microvolume inlet for precisely determining quadruple sulfur isotopic composition. Based on pore water chemistry and temperature profile, the subseafloor environment are divided into Unit-1, -2 and -3 with depth below surface. In Unit-1 (0-10 mbsf), fresh seawater is circulated, whereas in Unit-3 (>40 mbsf), hot hydrothermal fluid (>150 degrees Celsius) is stored below anhydrite cap. The Unit-2 is the mixing zone between the hydrothermal fluid and seawater. We found that the ?34S value of sulfate in the mixing zone was higher than those expected by simple mixing between seawater sulfate in Unit-1 (-20‰) and the hydrothermal component in Unit-3 (-16‰). The observed 34S-enrichment and decreased sulfate concentration suggest sulfate reduction took place in this hydrothermal system. Based on our model calculation assuming the mixing and reduction, apparent isotope effect for 33?, 34? and 36? are estimated to be -16.5‰, -32.2‰ and -62.5‰, respectively. These large fractionations together with slight D33S enrichment and D36S depletion all suggest that the sulfate reduction is microbial and not thermochemical process. Our numerical simulation also indicates that the sulfate is reduced before mixing with high temperature fluid, probably within the recharge zone of seawater. Based on these results, we will discuss microbial sulfur cycling in this subseafloor environment.

Aoyama, S.; Nishizawa, M.; Takai, K.; Ueno, Y.

2012-12-01

61

Barium enema (image)  

MedlinePLUS

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 ...

62

Radioactive mineral spring precipitates, their analytical and statistical data and the uranium connection  

USGS Publications Warehouse

Major radioactive mineral springs are probably related to deep zones of active metamorphism in areas of orogenic tectonism. The most common precipitate is travertine, a chemically precipitated rock composed chiefly of calcium carbonate, but also containing other minerals. The mineral springs are surface manifestations of hydrothermal conduit systems which extend downward many kilometers to hot source rocks. Conduits are kept open by fluid pressure exerted by carbon dioxide-charged waters rising to the surface propelled by heat and gas (CO2 and steam) pressure. On reaching the surface, the dissolved carbon dioxide is released from solution, and calcium carbonate is precipitated. Springs also contain sulfur species (for example, H2S and HS-), and radon, helium and methane as entrained or dissolved gases. The HS- ion can react to form hydrogen sulfide gas, sulfate salts, and native sulfur. Chemical salts and native sulfur precipitate at the surface. The sulfur may partly oxidize to produce detectable sulfur dioxide gas. Radioactivity is due to the presence of radium-226, radon-222, radium-228, and radon-220, and other daughter products of uranium-238 and thorium-232. Uranium and thorium are not present in economically significant amounts in most radioactive spring precipitates. Most radium is coprecipitated at the surface with barite. Barite (barium sulfate) forms in the barium-containing spring water as a product of the oxidation of sulfur species to sulfate ions. The relatively insoluble barium sulfate precipitates and removes much of the radium from solution. Radium coprecipitates to a lesser extent with manganese-barium- and iron-oxy hydroxides. R-mode factor analysis of abundances of elements suggests that 65 percent of the variance of the different elements is affected by seven factors interpreted as follows: (1) Silica and silicate contamination and precipitation; (2) Carbonate travertine precipitation; (3) Radium coprecipitation; (4) Evaporite precipitation; (5) Hydrous limonite precipitation and coprecipitated elements including uranium; (6) Rare earth elements deposited with detrital contamination (?); (7) Metal carbonate adsorption and precipitation. Economically recoverable minerals occurring at some localities in spring precipitates are ores of iron, manganese, sulfur, tungsten and barium and ornamental travertine. Continental radioactive mineral springs occur in areas of crustal thickening caused by overthrusting of crustal plates, and intrusion and metamorphism. Sedimentary rocks on the lower plate are trapped between the plates and form a zone of metamorphism. Connate waters, carbonate rocks and organic-carbon-bearing rocks react to extreme pressure and temperature to produce carbon dioxide, and steam. Fractures are forced open by gas and fluid pressures. Deep-circulating meteoric waters then come in contact with the reactive products, and a hydrothermal cell forms. When hot mineral-charged waters reach the surface they form the familiar hot mineral springs. Hot springs also occur in relation to igneous intrusive action or volcanism both of which may be products of the crustal plate overthrusting. Uranium and thorium in the sedimentary rocks undergoing metamorphism are sometimes mobilized, but mobilization is generally restricted to an acid hydrothermal environment; much is redeposited in favorable environments in the metamorphosed sediments. Radium and radon, which are highly mobile in both acid and alkaline aqueous media move upward into the hydrothermal cell and to the surface.

Cadigan, R.A.; Felmlee, J.K.

1982-01-01

63

Barium release system  

NASA Technical Reports Server (NTRS)

A chemical system is described for releasing a good yield of free barium neutral atoms and barium ions in the upper atmosphere and interplanetary space for the study of the geophysical properties of the medium. The barium is released in the vapor phase so that it can be ionized by solar radiation and also be excited to emit resonance radiation in the visible range. The ionized luminous cloud of barium becomes a visible indication of magnetic and electrical characteristics in space and allows determination of these properties over relatively large areas at a given time.

Lewis, B. W.; Stokes, C. S.; Smith, E. W.; Murphy, W. J. (inventors)

1973-01-01

64

Molecular Structure of Barium Chloride  

NSDL National Science Digital Library

Barium Chloride was the byproduct of the discovery of radium by Madame Curie. When refining radium, the final separation resulted in barium chloride and radium chloride. Electrophoresis of barium chloride produces small-scale amounts of barium atom. This can be used for obtaining barium for commercial uses. Applications of barium chloride include stimulating the heart and other muscles for medicinal purposes, and also for softening water. Other uses of barium chloride include the manufacturing of barium salts, as pesticide, pigments, boiler detergent, in purifying sugar, as mordant in dyeing and printing textiles, and in the manufacture of caustic soda, polymers, and stabilizers.

2002-08-15

65

Validation of an in situ solidification/stabilization technique for hazardous barium and cyanide waste for safe disposal into a secured landfill.  

PubMed

The aim of the present study was to devise and validate an appropriate treatment process for disposal of hazardous barium and cyanide waste into a landfill at a Common Hazardous Waste Treatment Storage Disposal Facility (CHWTSDF). The waste was generated during the process of hardening of steel components and contains cyanide (reactive) and barium (toxic) as major contaminants. In the present study chemical fixation of the contaminants was carried out. The cyanide was treated by alkali chlorination with calcium hypochlorite and barium by precipitation with sodium sulfate as barium sulfate. The pretreated mixture was then solidified and stabilized by binding with a combination of slag cement, ordinary Portland cement and fly ash, molded into blocks (5 x 5 x 5 cm) and cured for a period of 3, 7 and 28 days. The final experiments were conducted with 18 recipe mixtures of waste + additive:binder (W:B) ratios. The W:B ratios were taken as 80:20, 70:30 and 50:50. The optimum proportions of additives and binders were finalized on the basis of the criteria of unconfined compressive strength and leachability. The leachability studies were conducted using the Toxicity Characteristic Leaching Procedure. The blocks were analyzed for various physical and leachable chemical parameters at the end of each curing period. Based on the results of the analysis, two recipe mixtures, with compositions - 50% of [waste + (120 g Ca(OCl)(2) + 290 g Na(2)SO(4)) kg(-1) of waste] + 50% of binders, were validated for in situ stabilization into a secured landfill of CHWTSDF. PMID:20430516

Vaidya, Rucha; Kodam, Kisan; Ghole, Vikram; Surya Mohan Rao, K

2010-09-01

66

Radium and barium removal through blending hydraulic fracturing fluids with acid mine drainage.  

PubMed

Wastewaters generated during hydraulic fracturing of the Marcellus Shale typically contain high concentrations of salts, naturally occurring radioactive material (NORM), and metals, such as barium, that pose environmental and public health risks upon inadequate treatment and disposal. In addition, fresh water scarcity in dry regions or during periods of drought could limit shale gas development. This paper explores the possibility of using alternative water sources and their impact on NORM levels through blending acid mine drainage (AMD) effluent with recycled hydraulic fracturing flowback fluids (HFFFs). We conducted a series of laboratory experiments in which the chemistry and NORM of different mix proportions of AMD and HFFF were examined after reacting for 48 h. The experimental data combined with geochemical modeling and X-ray diffraction analysis suggest that several ions, including sulfate, iron, barium, strontium, and a large portion of radium (60-100%), precipitated into newly formed solids composed mainly of Sr barite within the first ? 10 h of mixing. The results imply that blending AMD and HFFF could be an effective management practice for both remediation of the high NORM in the Marcellus HFFF wastewater and beneficial utilization of AMD that is currently contaminating waterways in northeastern U.S.A. PMID:24367969

Kondash, Andrew J; Warner, Nathaniel R; Lahav, Ori; Vengosh, Avner

2014-01-21

67

Isotopic Zonation Within Sulfate Evaporite Mineral Crystals Reveal Quantitative Paleoenvironment Details  

NASA Astrophysics Data System (ADS)

Isotopic variations measured within a single crystal of hydrated magnesium sulfate are greater than 30 permil for delta 2-H, almost 10 permil for ?18O in water of hydration; and greater than 3 permil in sulfate oxygen. These results are interpreted to indicate the relative humidity of the system during evaporation (15 to 20 percent in this test case) and constrain the volume of water involved. The theoretical basis of this system is the isotopic fractionation between the species in solution and those precipitated as evaporite salts. Precipitation preferentially accumulates more of the heavy isotopes of sulfur and oxygen in mineral sulfate, relative to sulfate in solution. During the course of mineral growth this leads to successive depletion of the respective heavier isotopes in the residual brine reflected in a parallel trend in successive precipitates or even in successive zones within a single crystal. The change in isotopic composition at any one time during the process, relative to the initial value, can be described by an isotopic version of the Rayleigh Fractionation equation, depending only on the extent of the completion of the process and the relevant fractionation factor. Evaporation preferentially removes isotopically lighter hydrogen and oxygen leading to successive extents of enrichment in the respective heavier isotopes in the residual water. However, the relative effects on hydrogen and oxygen isotopes differs as function of relative humidity [1]. ALL OF THESE CHANGES ARE PRESERVED IN THE MINERAL ISOTOPE COMPOSITIONS. We precipitated barium sulfate from epsomite or gypsum samples, which was reduced at 1450°C in the presence of graphite and glassy carbon in a Finnigan TC/EA to produce CO for O isotopic analysis in a Finnigan 253 mass spectrometer, while a separate subsample was oxidized to SO2 in a Costech Elemental Analyzer. However, to make progress with this approach we needed to make a large number of measurements of hydration water and so we developed a new analytical method [2]. We use a modification of the standard TC/EA continuous-flow protocol to measure both hydrogen and oxygen of water of hydration from the same small sample. We have proved the concept of this new approach by analyzing zones within crystals and individual grains, growing epsomite (magnesium sulfate heptahydrate) in the laboratory and by analysis of natural gypsum evaporites. We are now exploring the effects of varying the controlling parameters. Eventual application to Martian sulfates will reveal amount of water involved in sulfate formation, its isotopic composition(s) and details of the paleo-atmospheric humidity. [1] Gat JR and Gonfiantini R, (Eds) (1981) IAEA Technical Report Series. [2] Rohrssen MK, Brunner B Mielke RE and Coleman M (2008) Analyt. Chem. (in press).

Coleman, M.; Rhorssen, M.; Mielke, R. E.

2008-12-01

68

Effect of heat treatment on the phase composition, structure and magnetic properties of M-type barium hexaferrite  

NASA Astrophysics Data System (ADS)

Effect of the heat treatment of carbonate-hydroxide precipitates on the phase composition, structure and magnetic properties of M-type barium hexaferrite has been investigated using the M?ssbauer spectroscopy, X-ray phase analysis and magnetic measurements. The distribution of Fe3+ ions over structural sites of barium hexaferrite with different degree of ferritizations has been defined. The conditions of single-domain behavior of barium hexaferrite nanoparticles in the magnetic field have been discussed. Obtained results explain the formation of magnetic structure during the synthesis of barium hexaferrite. This information could further be used for optimizing conditions for synthesis of nanosized barium hexaferrite with high-level properties.

Pashkova, E. V.; Solovyova, E. D.; Kolodiazhnyi, T. V.; Ivanitskii, V. P.; Belous, A. G.

2014-11-01

69

Barium Abundances in Cepheids  

E-print Network

We derived the barium atmospheric abundances for a large sample of Cepheids, comprising 270 stars. The sample covers a large range of galactocentric distances, from about 4 to 15 kpc, so that it is appropriated to investigate the existence of radial barium abundance gradients in the galactic disc. In fact, this is the first time that such a comprehensive analysis of the distribution of barium abundances in the galactic disc is carried out. As a result, we conclude that the Ba abundance distribution can be characterized by a zero gradient. This result is compared with derived gradients for other elements, and some reasons are briefly discussed for the independence of the barium abundances upon galactocentric distances.

Andrievsky, S M; Korotin, S A; Luck, R E; Kovtyukh, V V; Maciel, W J

2012-01-01

70

Dissolution of Barium from Barite in Sewage Sludges and Cultures of Desulfovibrio desulfuricans  

PubMed Central

High concentrations of total barium, ranging from 0.42 to 1.58 mg(middot)g(sup-1) (dry weight) were found in sludges of two sewage treatment plants near Florence, Italy. Barium concentrations in the suspended matter decreased as redox potential values changed from negative to positive. An anoxic sewage sludge sample was aerated, and 30% of the total barium was removed in 24 h. To demonstrate that barium was solubilized from barite by sulfate-reducing bacteria, a strain of Desulfovibrio desulfuricans was used to study the solubilization of barium from barite under laboratory conditions. During cell growth with different concentrations of barite from 0.01 to 0.3 g(middot)liter(sup-1) (the latter is the MIC) as the only source of sulfates in the cultures, the D. desulfuricans strain accumulated barium up to 0.58 (mu)g(middot)mg(sup-1) (dry weight). Three times the quantity of barium was dissolved by bacteria than in the uninoculated medium (control). The unexpectedly low concentration of soluble barium (1.2 mg of Ba(middot)liter(sup-1)) with respect to the quantity expected (109 mg of Ba(middot)liter(sup-1)), calculated on the basis of the free H(inf2)S evolved from the dissimilatory reduction of sulfate from barite, was probably due to the formation of other barium compounds, such as witherite (BaCO(inf3)) and the transient species barium sulfide (BaS). The D. desulfuricans strain, growing on barite, formed visible aggregates. Confocal microscopy analysis showed that aggregates consisted of bacteria and barite. After 3 days of incubation, several autofluorescent crystals surrounded by a dissolution halo were observed. The crystals were identified as BaS by comparison with the commercial compound. PMID:16535353

Baldi, F.; Pepi, M.; Burrini, D.; Kniewald, G.; Scali, D.; Lanciotti, E.

1996-01-01

71

Chondroitin sulfate  

MedlinePLUS

... sulfate is manufactured from animal sources, such as cow cartilage. Chondroitin sulfate is used for osteoarthritis. It ... those that might transmit bovine spongiform encephalopathy (mad cow disease). So far, there are no reports of ...

72

Yielding Unexpected Results: Precipitation of Ba[subscript3](PO[subscript4])[subscript2] and Implications for Teaching Solubility Principles in the General Chemistry Curriculum  

ERIC Educational Resources Information Center

Precipitation of barium phosphate from aqueous solutions of a barium salt and a phosphate salt forms the basis for a number of conclusions drawn in general chemistry. For example, the formation of a solid white precipitate is offered as evidence that barium phosphate is insoluble. Furthermore, analysis of the supernatant is used to illustrate the…

Hazen, Jeffery L.; Cleary, David A.

2014-01-01

73

Barium Ion Trapping Rebecca Schutzengel  

E-print Network

Barium Ion Trapping Rebecca Schutzengel Franklin W. Olin College of Engineering University of Washington INT REU August 20, 2012 Rebecca Schutzengel Barium Ion Trapping August 20, 2012 1 / 12 #12;Uses for Ion Trapping Bell's Inequality tests Quantum Computing Rebecca Schutzengel Barium Ion Trapping August

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

74

Observed Barium Emission Rates  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

75

Sources of sulfate supporting anaerobic metabolism in a contaminated aquifer  

USGS Publications Warehouse

Field and laboratory techniques were used to identify the biogeochemical factors affecting sulfate reduction in a shallow, unconsolidated alluvial aquifer contaminated with landfill leachate. Depth profiles of 35S-sulfate reduction rates in aquifer sediments were positively correlated with the concentration of dissolved sulfate. Manipulation of the sulfate concentration in samples revealed a Michaelis-Menten-like relationship with an apparent Km and Vmax of approximately 80 and 0.83 ??M SO4-2??day-1, respectively. The concentration of sulfate in the core of the leachate plume was well below 20 ??M and coincided with very low reduction rates. Thus, the concentration and availability of this anion could limit in situ sulfate-reducing activity. Three sulfate sources were identified, including iron sulfide oxidation, barite dissolution, and advective flux of sulfate. The relative importance of these sources varied with depth in the alluvium. The relatively high concentration of dissolved sulfate at the water table is attributed to the microbial oxidation of iron sulfides in response to fluctuations of the water table. At intermediate depths, barite dissolves in undersaturated pore water containing relatively high concentrations of dissolved barium (???100 ??M) and low concentrations of sulfate. Dissolution is consistent with the surface texture of detrital barite grains in contact with leachate. Laboratory incubations of unamended and barite-amended aquifer slurries supported the field observation of increasing concentrations of barium in solution when sulfate reached low levels. At a deeper highly permeable interval just above the confining bottom layer of the aquifer, sulfate reduction rates were markedly higher than rates at intermediate depths. Sulfate is supplied to this deeper zone by advection of uncontaminated groundwater beneath the landfill. The measured rates of sulfate reduction in the aquifer also correlated with the abundance of accumulated iron sulfide in this zone. This suggests that the current and past distributions of sulfate-reducing activity are similar and that the supply of sulfate has been sustained at these sites.

Ulrich, G.A.; Breit, G.N.; Cozzarelli, I.M.; Suflita, J.M.

2003-01-01

76

Semiconducting barium titanate  

Microsoft Academic Search

Barium titanate, which is well known as a basic ferroelectric material, is also of interest when doped because of the interaction between semiconductivity and ferroelectricity. The resistance of blocking layers at surfaces and grain-boundaries is governed mainly by the ferroelectric properties, so that a resistance jump of four decades is observed on heating above the Curie temperature. A survey of

W. Heywang

1971-01-01

77

Esophagram (Barium Swallow Study)  

MedlinePLUS

... up. You will be given a gown to wear. The esophagram barium swallow uses x-rays and anyone who is pregnant cannot be in the room during the x-ray. During the Test Before the study you/your child will need ...

78

Low density barium and bentonite mixture versus high density barium: a comparative study to optimize negative gastrointestinal contrast agents for MRI.  

PubMed

The purpose of this study was to compare the patient tolerance and efficacy, as magnetic resonance imaging negative oral contrast agents, of a mixture of clay compound bentonite and low density barium sulfate suspension with that of higher density barium sulfate. Twenty patients were randomized into two groups: 10 patients receiving a mixture of low concentration 60% w/v barium sulfate plus 2.5% w/v bentonite, and 10 patients receiving 220% w/v barium sulfate Liuqid-HD (E-Z-EM, Westbury, NY). Post-contrast Spin-echo (SE) T1- and T2-weighted images (WI) were obtained on a 1.0T magnet. Two independent readers scored the overall intraluminal signal intensity and delineation of the gastrointestinal tract and adjacent organs. Patient acceptance was evaluated via a short questionnaire, by recording spontaneous comments and documenting the quantity of contrast agent ingested. There was greater intraluminal bowel signal reduction and organ delineation with 220% w/v barium than with the barium-bentonite mixture on both SE T1WI (p = 0.03) and SE T2WI (p = 0.42). With both agents there was greater signal reduction on SE T2WI than SE T1WI. Higher scores for organ delineation for both contrast agents were seen with SE T1WI. With 220% w/v barium, there was significantly better delineation of the pancreatic body (p = 0.02) and pancreatic tail (p = 0.02) on T1WI compared with SE T2WI. With the barium-bentonite mixture, SE T1WI showed improved delineation of jejunum compared with SE T2WI (p = 0.03). There were no statistically significant differences between the volume of contrast ingested in the two groups. Abdominal cramps were recorded for one patient in each group. These results suggest that barium-bentonite mixture, although useful as a negative gastro-intestinal contrast agent, is not as effective as 220% w/v barium. Further studies with a larger patient population and concentration optimization studies are needed. PMID:9364949

Paley, M R; Nicolas, A I; Mergo, P J; Torres, G M; Burton, S S; Ros, P R

1997-01-01

79

Methods for producing monodispersed particles of barium titanate  

DOEpatents

The present invention is a low-temperature controlled method for producing high-quality, ultrafine monodispersed nanocrystalline microsphere powders of barium titanate and other pure or composite oxide materials having particles ranging from nanosized to micronsized particles. The method of the subject invention comprises a two-stage process. The first stage produces high quality monodispersed hydrous titania microsphere particles prepared by homogeneous precipitation via dielectric tuning in alcohol-water mixed solutions of inorganic salts. Titanium tetrachloride is used as an inorganic salt precursor material. The second stage converts the pure hydrous titania microsphere particles into crystalline barium titanate microsphere powders via low-temperature, hydrothermal reactions.

Hu, Zhong-Cheng (Knoxville, TN)

2001-01-01

80

Rapid barium removal in the Delaware estuary  

SciTech Connect

Six profiles of dissolved barium covering the entire salinity range of the Delaware River and Bay estuary from March through September 1996 were collected and analyzed. The profiles are similar to one another in both shape and magnitude except for one attribute. A sudden ({le} 24 days), nearly complete (>90%) removal of dissolved Ba in midestuary occurs in mid-May followed by an 80% recovery in early June. This removal appears to be temporally and spatially coupled to the end of the spring bloom. Based on such episodic behavior, and on recent work with flocculation of diatom exudates, the authors conclude that the Ba depletion is caused by barite precipitation in the estuary during the late stages of the bloom. This would imply that lower estuary and inner coastal margin sediments associated with eutrophic estuaries receive a seasonal pulse of barite. The suddenness of this event also implies that sedimentary barite is strongly influenced by high productivity events. Comparison of the riverine Ba concentration with the effective riverine end member after desorptive barium release yields an estimated 30--40 nM Ba available from the suspended sediments as they enter the estuary. This estimate is supported by excess barium in unfiltered samples over filtered samples taken from the river and also by calculations done elsewhere.

Stecher, H.A. III [Univ. of Delaware, Lewes, DE (United States). College of Marine Studies] [Univ. of Delaware, Lewes, DE (United States). College of Marine Studies; [Univ. of Delaware, Newark, DE (United States). Dept. of Geology; Kogut, M.B. [Univ. of Washington, Seattle, WA (United States). School of Oceanography] [Univ. of Washington, Seattle, WA (United States). School of Oceanography

1999-04-01

81

75 FR 33824 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013, 2014

...No. 731-TA-149 (Third Review)] Barium Chloride From China Determination On the...revocation of the antidumping duty order on barium chloride from China would be likely to...Publication 4157 (June 2010), entitled Barium Chloride from China: Investigation...

2010-06-15

82

75 FR 19657 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013, 2014

...No. 731-TA-149 (Third Review)] Barium Chloride From China AGENCY: United States...concerning the antidumping duty order on barium chloride from China...revocation of the antidumping duty order on barium chloride from China would be likely...

2010-04-15

83

Properties of Semiconductive Barium Titanates  

Microsoft Academic Search

The resistivity of barium titanate which is usually of the order of 109˜1012 ohm-cm, may be remarkably reduced with suitable control in valency. The valency-controlled barium titanate, whose resistivity is of the order of 10˜104 ohm-cm at room temperature, shows anomalous positive character in the temperature dependency of the resistivity. For example, the resistivity of barium titanate containing 0.1 mol.

Osamu Saburi

1959-01-01

84

Barium uranyl diphosphonates  

SciTech Connect

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 mineralizing agent and a ligand.

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

85

Removal of Sulfate Ion From AN-107 by Evaporation  

SciTech Connect

Hanford low-activity waste solutions contain sulfate, which can cause accelerated corrosion of the vitrification melter and unacceptable operating conditions. A method is needed to selectively separate sulfate from the waste. An experiment was conducted to evaluate evaporation for removing sulfate ion from Tank AN-107 low-activity waste. Two evaporation steps were performed. In the first step, the volume was reduced by 55% while in the second step, the liquid volume was reduced another 22%. Analysis of the solids precipitated during these evaporations revealed that large amounts of sodium nitrate and nitrite co-precipitated with sodium sulfate. Many other waste components precipitated as well. It can be concluded that sulfate removal by precipitation is not selective, and thus, evaporation is not a viable option for removing sulfate from the AN-107 liquid.

GJ Lumetta; GS Klinger; DE Kurath; RL Sell; LP Darnell; LR Greenwood; CZ Soderquist; MJ Steele; MW Urie; JJ Wagner

2000-08-02

86

21 CFR 82.3 - Definitions.  

Code of Federal Regulations, 2013 CFR

...term blanc fixe means a suspension in water of precipitated barium sulfate. (i) The term gloss white means a suspension in water of co-precipitated aluminum hydroxide and barium sulfate. (j) The term mixed oxides means the...

2013-04-01

87

21 CFR 82.3 - Definitions.  

Code of Federal Regulations, 2010 CFR

...term blanc fixe means a suspension in water of precipitated barium sulfate. (i) The term gloss white means a suspension in water of co-precipitated aluminum hydroxide and barium sulfate. (j) The term mixed oxides means the...

2010-04-01

88

21 CFR 82.3 - Definitions.  

Code of Federal Regulations, 2012 CFR

...term blanc fixe means a suspension in water of precipitated barium sulfate. (i) The term gloss white means a suspension in water of co-precipitated aluminum hydroxide and barium sulfate. (j) The term mixed oxides means the...

2012-04-01

89

21 CFR 82.3 - Definitions.  

Code of Federal Regulations, 2011 CFR

...term blanc fixe means a suspension in water of precipitated barium sulfate. (i) The term gloss white means a suspension in water of co-precipitated aluminum hydroxide and barium sulfate. (j) The term mixed oxides means the...

2011-04-01

90

21 CFR 82.3 - Definitions.  

Code of Federal Regulations, 2014 CFR

...term blanc fixe means a suspension in water of precipitated barium sulfate. (i) The term gloss white means a suspension in water of co-precipitated aluminum hydroxide and barium sulfate. (j) The term mixed oxides means the...

2014-04-01

91

Magnesium sulfate.  

PubMed

Since the first American report on the use of magnesium sulfate tocolysis in 1977, its popularity as a tocolytic agent has increased progressively. Primarily because of its safety and familiarity, magnesium has become the primary tocolytic agent in the majority of U.S. centers. The exact mechanism of action is unknown, and long-term effects on neonates have not been studied. Although randomized studies show similar success compared to other tocolytic agents, no placebo-controlled study has shown neonatal improvement with magnesium sulfate tocolysis. This is similar to the studies of beta-sympathomimetic tocolytics and has led some authors (e.g., Higby) to suggest that safe dosages of magnesium sulfate are ineffective in preventing preterm birth and should not be used as a tocolytic agent. Although magnesium sulfate, like other tocolytics, has not fulfilled the initial promise of preventing preterm birth, it does appear if used correctly in a well identified population of patients to at least transiently inhibit preterm labor as well as other tocolytic agents with fewer side effects and fewer contraindications. PMID:8616968

Gordon, M C; Iams, J D

1995-12-01

92

Discovery of the Barium Isotopes  

E-print Network

Thirty-eight barium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

A. Shore; A. Fritsch; J. Q. Ginepro; M. Heim; A. Schuh; M. Thoennessen

2009-08-13

93

Discovery of the barium isotopes  

SciTech Connect

Thirty-eight barium isotopes have been observed so far and the discovery of these isotopes is discussed here. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

Shore, A.; Fritsch, A.; Ginepro, J.Q.; Heim, M.; Schuh, A. [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Thoennessen, M., E-mail: thoennessen@nscl.msu.ed [National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

2010-11-15

94

Barium light source method and apparatus  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

95

Barium swallow study in routine clinical practice: a prospective study in patients with chronic cough*,**  

PubMed Central

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. PMID:24473762

Nin, Carlos Shuler; Marchiori, Edson; Irion, Klaus Loureiro; Paludo, Artur de Oliveira; Alves, Giordano Rafael Tronco; Hochhegger, Daniela Reis; Hochhegger, Bruno

2013-01-01

96

Abundance analysis of barium and mild barium stars  

E-print Network

High signal to noise, high resolution spectra were obtained for a sample of normal, mild barium, and barium giants. Atmospheric parameters were determined from the FeI and FeII lines. Abundances for Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, and Gd, were determined from equivalent widths and model atmospheres in a differential analysis, with the red giant Eps Vir as the standard star. The different levels of s-process overabundances of barium and mild barium stars were earlier suggested to be related to the stellar metallicity. Contrary to this suggestion, we found in this work no evidence of barium and mild barium to having different range in metallicity. However, comparing the ratio of abundances of heavy to light s-process elements, we found some evidence that they do not share the same neutron exposure parameter. The exact mechanism controlling this difference is still not clear. As a by-product of this analysis we identify two normal red giants misclassified as mild barium stars. The relevance of this finding is discussed. Concerning the suggested nucleosynthetic effects possibly related to the s-process, for elements like Cu, Mn, V and Sc, we found no evidence for an anomalous behavior in any of the s-process enriched stars analyzed here. However, further work is still needed since a clear [Cu/Fe] vs. [Ba/H] anticorrelation exists for other s-process enriched objects.

R. Smiljanic; G. F. Porto de Mello; L. da Silva

2007-04-02

97

Observation and theory of the barium releases from the CRRES satellite  

NASA Technical Reports Server (NTRS)

The relationship between releases of barium from the NASA Combined Release and Radiation Effects Satellite (CRRES) and enhanced auroral activity is discussed with reference to observational data. Barium releases were conducted at a variety of altitudes and injection velocities, and plasma irregularities are reported as a result of the interactions. Auroral activity increased within 5 min of each release, and references are made to the effects on diamagnetic cavities, bulk ion motion, and stimulated electron and ion precipitation. Artificially created structured diamagnetic cavities are noted for each release, plasma waves are generated by the high-speed ion clouds, and enhanced ionization is found in the critical ionization-velocity process. Barium releases are effective in stimulating electron precipitation, and the observed irregularities are related to cycloid bunching of the initial ion distributions.

Bernhardt, P. A.; Huba, J. D.; Scales, W. A.; Wescott, E. M.; Stenbaek-Nielsen, H. C.

1992-01-01

98

Barium and CH Stars The classical barium (or ``Ba II'') stars are red  

E-print Network

Barium and CH Stars The classical barium (or ``Ba II'') stars are red giants whose spectra show strong absorption lines of barium, strontium, and certain other heavy elements, as well as strong transfer in binary sys­ tems that drastically alters the surface compo­ sition of a companion star. Barium

Bond, Howard E.

99

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

Microsoft Academic Search

In this study, we present the first experimental results for stable barium (Ba) isotope (Ba\\/Ba) fractionation during low-temperature formation of the anhydrous double carbonate BaMn[CO3]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

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

2012-01-01

100

Barium Ions for Quantum Computation Matthew Dietrich  

E-print Network

Barium Ions for Quantum Computation Matthew Dietrich A dissertation submitted in partial of the manuscript made from microform." Signature Date #12;#12;University of Washington Abstract Barium Ions Department of Physics Barium ion is investigated as a hyperfine qubit. 137Ba+ is trapped in a linear Paul

Blinov, Boris

101

Quantum manipulation on the Barium quadrupolar transition  

E-print Network

Quantum manipulation on the Barium quadrupolar transition A diploma thesis in physics submitted and stabilization of a new fiber laser system to ma- nipulate the Barium quadrupolar transition, with the aim with a single Barium ion trapped in a linear Paul trap and Doppler cooled to the Lamb Dicke regime. The narrow

Blatt, Rainer

102

Distribution and source of barium in ground water at Cattaraugus Indian Reservation, southwestern New York  

USGS Publications Warehouse

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)

Moore, R.B.; Staubitz, W.W.

1984-01-01

103

Preparation of carboxymethyl cellulose sulfates and its application as anticoagulant and wound dressing.  

PubMed

Tissue engineering is aiming to build an artificial environment or biological scaffold material that imitates the living environment of cells in the body. In this work, carboxymethyl cellulose sulfates were prepared by reacting carboxymethyl cellulose with N(SO3Na)3 which was synthesized by sodium bisulfite and sodium nitrite in aqueous solution. The reaction conditions affected the degree of substitution (DS) were measured by the barium sulfate nephelometry method. And the anticoagulant activity of carboxymethyl cellulose sulfates with different DS, concentration and molecular weights were investigated by the activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT). In addition, the effect of carboxymethyl cellulose sulfates on wound healing had been evaluated by the rate of wound healing and the histological examinations. The results indicated that the introduction of sulfate groups into the carboxymethyl cellulose sulfates improved its anticoagulant activity, and the wound dressings treated with carboxymethyl cellulose sulfates obviously promoted wound healing. PMID:24582936

Fan, Lihong; Zhou, Xiaoyu; Wu, Penghui; Xie, Weiguo; Zheng, Hua; Tan, Wang; Liu, Shuhua; Li, Qingyuan

2014-05-01

104

Computer modelling of barium titanate  

Microsoft Academic Search

Barium titanate is an important material for both scientific and industrial applications. Much of the interest centres around its ferroelectric properties, since it is structurally the most simple in this class. In addition rare-earth doped ceramics are found to exhibit a very steep positive temperature coefficient of resistance (PTCR) above the Curie point. The theory of this PTCR effect is

G. V. Lewis; C. R. A. Catlow

1983-01-01

105

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

2011-07-01

106

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

2010-07-01

107

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

2012-07-01

108

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

2013-07-01

109

40 CFR 721.10011 - Barium calcium manganese strontium oxide.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Barium calcium manganese strontium oxide. 721.10011...Chemical Substances § 721.10011 Barium calcium manganese strontium oxide. (a...chemical substance identified as barium calcium manganese strontium oxide (PMN...

2014-07-01

110

The L equals 6.7 quiet time barium shaped charge injection experiment 'Chachalaca'  

NASA Technical Reports Server (NTRS)

Near dawn on October 9, 1972, UT, a barium plasma injection experiment was carried out from Poker Flat, Alaska, during quiet magnetic conditions (Kp equals 1+). The visible plasma flux tube produced was more diffuse than the flux tubes in previous experiments, but it could be tracked for 30 min out to an altitude of 2.5 earth radii. The flux tube remained integral for about 20 min, when a single striation separated from the main streak. Comparisons of the observed flux tube orientation with theoretical field models show no significant deviations ascribable to field-aligned currents. Cross-field drift rates of the foot of the flux tube indicate an E field of approximately 7 mV/m at 200-km altitude. Although an attempt was made via a jet aircraft flight, barium ions were not detected in the southern conjugate region. No energetic particle precipitation phenomena were observed which could be ascribed to the barium plasma injection.

Wescott, E. M.; Stenbaek-Nielsen, H. C.; Davis, T. N.; Rieger, E. P.; Peek, H. M.; Bottoms, P. J.

1975-01-01

111

The problem of the barium stars  

NASA Technical Reports Server (NTRS)

Ultraviolet observations of barium stars and other cool stars with peculiar element abundances are reported. Those observations attempted to find hot white dwarf companions. Among six real barium stars studied, only Zeta Cap was found to have a white dwarf companion. Among seven mild, or marginal, barium stars studied, at least three were found to have hot subluminous companions. It is likely that all of them have white dwarf companions.

Bohm-Vitense, E.; Nemec, J.; Proffitt, C.

1984-01-01

112

75 FR 20625 - Barium Chloride From China  

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2010-04-20

113

Sulfate Reduction at pH 4.0 for Treatment of Process and Wastewaters  

Microsoft Academic Search

Acidic industrial process and wastewaters often contain high sulfate and metal concentrations and their direct biological treatment is thus far not possible as biological processes at pH < 5 have been neglected. Sulfate-reducing bacteria convert sulfate to sulfide that can subsequently be used to recover metals as metal-sulfides precipitate. This study reports on high-rate sulfate reduction with a mixed microbial

Martijn F. M. Bijmans; Erik de Vries; Chun-Hui Yang; Cees J. N. Buisman; Piet N. L. Lens; Mark Dopson

2010-01-01

114

Hydrometallurgical process for recovering iron sulfate and zinc sulfate from baghouse dust  

DOEpatents

A process for recovering zinc-rich and iron-rich fractions from the baghouse dust that is generated in various metallurgical operations, especially in steel-making and other iron-making plants, comprises the steps of leaching the dust by hot concentrated sulfuric acid so as to generate dissolved zinc sulfate and a precipitate of iron sulfate, separating the precipitate from the acid by filtration and washing with a volatile liquid, such as methanol or acetone, and collecting the filtered acid and the washings into a filtrate fraction. The volatile liquid may be recovered by distillation, and the zinc may be removed from the filtrate by alternative methods, one of which involves addition of a sufficient amount of water to precipitate hydrated zinc sulfate at 10 C, separation of the precipitate from sulfuric acid by filtration, and evaporation of water to regenerate concentrated sulfuric acid. The recovery of iron may also be effected in alternative ways, one of which involves roasting the ferric sulfate to yield ferric oxide and sulfur trioxide, which can be reconverted to concentrated sulfuric acid by hydration. The overall process should not generate any significant waste stream. 1 figure.

Zaromb, S.; Lawson, D.B.

1994-02-15

115

Communications to the Editor Synthesis of Monodisperse Nanoparticles of Barium  

E-print Network

Communications to the Editor Synthesis of Monodisperse Nanoparticles of Barium Titanate: Toward of barium titanate, BaTiO3, with diameters ranging from 6 to 12 nm. Barium titanate is a room,10 In the synthesis developed here, barium titanium ethyl hexano-isopropoxide (A

116

Precipitation Protocols  

NSDL National Science Digital Library

The purpose of this activity is to determine the amount of moisture input to the local environment by measuring rain and snowfall and to measure the pH of precipitation. To do so students use a rain gauge and a snowboard to measure the daily amount of precipitation. Special pH measuring techniques for precipitation are used to determine the pH of rain and melted snow. Intended outcomes are that students will understand that precipitation is measured in depth and this depth is assumed to apply to a large area, that precipitation has a pH that can vary, and that snow is an input of water to the surface just like rain and each snowfall is equivalent to some amount of rainfall. Supporting background materials for both student and teacher are included.

The GLOBE Program, UCAR (University Corporation for Atmospheric Research)

2003-08-01

117

Methods for sulfate removal in liquid-phase catalytic hydrothermal gasification of biomass  

DOEpatents

Processing of wet biomass feedstock by liquid-phase catalytic hydrothermal gasification must address catalyst fouling and poisoning. One solution can involve heating the wet biomass with a heating unit to a pre-treatment temperature sufficient for organic constituents in the feedstock to decompose, for precipitates of inorganic wastes to form, for preheating the wet feedstock in preparation for subsequent removal of soluble sulfate contaminants, or combinations thereof. Processing further includes reacting the soluble sulfate contaminants with cations present in the feedstock material to yield a sulfate-containing precipitate and separating the inorganic precipitates and/or the sulfate-containing precipitates out of the wet feedstock. Having removed much of the inorganic wastes and the sulfate contaminants that can cause poisoning and fouling, the wet biomass feedstock can be exposed to the heterogeneous catalyst for gasification.

Elliott, Douglas C; Oyler, James R

2014-11-04

118

Solubility of uranous sulfate in aqueous sulfuric acid solution  

NASA Astrophysics Data System (ADS)

To provide important thermodynamic data for use in uranium hydrometallurgy, solubilities of uranous sulfate were determined as a function of free acid concentration and temperature. Two sets of experiments were performed in this study. One set was the precipitation experiments of uranous sulfate crystals, in which concentrated uranous sulfate solution was mixed with sulfuric acid solution of suitable concentration. The other set was the dissolution experiments of uranous sulfate crystals in aqueous sulfuric acid solutions. It is noteworthy that good agreement exists between the solubilities determined by the two methods. At elevated temperatures, say, 363 K, the presence of free sulfuric acid is required to avoid precipitation of uranous hydroxide resulting from the hydrolysis of uranous sulfate. Generally speaking, however, an increase in free sulfuric acid concentration results in a slight decrease in uranous sulfate solubility. The elevation of solution temperature causes a decrease in solubility of uranous sulfate. It should be noted that the solid uranous sulfates equilibrated with saturated solutions at 298 K were U(SO4)2 2H2O in dilute sulfuric acid solution and U(SO4)2 4H2O in concentrated sulfuric acid solution, while those at 333 K and 363 K were mainly U(SO4)2 4H2O.

Suzuki, Shigeru; Hirono, Shuichiro; Awakura, Yasuhiro; Majima, Hiroshi

1990-10-01

119

New barium ferrite particles: Spherical shape  

NASA Astrophysics Data System (ADS)

Pure and ZnTi-doped spherical barium ferrite particles were prepared using two different methods: semicoprecipitation and ultrasonic spray pyrolysis. The ultrasonic spray pyrolysis method was more effective in controlling particle shape. Particle size was in between 0.27 and 0.3 ?m. Coercivity and saturation magnetization were in the range of 1000 to 5000 Oe and 49 to 53 emu/g, respectively. Crystallization of amorphous Ba-Fe-O spherical precursors occurs at a lower temperature than Ba-Fe-Zn-Ti-O precursors. ?M measurement shows that magnetic interaction in spherical barium ferrite tape is weaker than hexagonal platelet barium ferrite.

Hong, Y. K.; Jung, H. S.

1999-04-01

120

Preparation and characterization of uniform particles of flufenamic acid and its calcium and barium salts.  

PubMed

Uniform fully dispersed particles of flufenamic acid, a widely used anti-inflammatory drug, were prepared by two different methods. In the first one, the drug solution in organic solvents was added to a non-solvent (water or aqueous solutions of stabilizers); while in the second procedure the drug was precipitated by acidifying its basic aqueous solutions. In addition calcium and barium salts of uniform spherical particles were obtained by precipitation in aqueous basic solutions of the drug. These salts are supposed to improve the drug reactivity. The prepared dispersions of the drug and its salts were examined by scanning electron microscopy, X-ray diffractometry and electrophoresis. PMID:22703985

Mohamed, Amr Ali; Matijevi?, Egon

2012-09-01

121

Roles of Pt and BaO in the Sulfation of Pt/BaO/Al2O3 Lean NOx Trap Materials: Sulfur K-edge XANES and Pt LIII XAFS Studies  

SciTech Connect

The roles of barium oxide and platinum during the sulfation of Pt-BaO/Al2O3 lean NOx trap catalysts were investigated by S K edge XANES (X-ray absorption near-edge spectroscopy) and Pt LIII XAFS (X-ray absorption fine structure). All of the samples studied (Al2O3, BaO/Al2O3, Pt/Al2O3 and Pt-BaO/Al2O3) were pre-sulfated prior to the X-ray absorption measurements. It was found that barium oxide itself has the ability to directly form barium sulfate even in the absence of Pt and gas phase oxygen. In the platinum-containing samples, the presence of Pt-O species plays an important role in the formation of sulfate species. Even if barium and aluminum sites are available for SO2 to form sulfate, for the case of the BaO(8)/Al2O3 sample, where the barium coverage is about 0.26 ML, S XANES spectroscopy results show that barium sulfates are preferentially produced over aluminum sulfates . When oxygen is absent from the gas phase, the sulfation route that involves Pt-O is eliminated after the initially present Pt-O species are completely consumed. In this case, formation of sulfates is suppressed unless barium oxide is also present. Pt LIII XAFS results show that the first coordination sphere around the Pt atoms in the Pt particles is dependent upon the redox nature of the gas mixture used during the sulfation process. Sulfation under reducing environments (e.g. SO2+H2) leads to formation of Pt-S bonds, while oxidizing conditions (e.g. SO2+O2) continue to show the presence of Pt-O bonds. In addition, the former condition was found to give rise to a higher degree of Pt sintering than the latter one. This result explains why samples sulfated under reducing conditions had lower NOx uptakes than those sulfated under oxidizing conditions. Therefore, our results provide needed information for the development of optimum practical operation conditions (e.g. sulfation or desulfation) for lean NOx trap catalysts that minimize deactivation by sulfur.

Kim, Do Heui; Kwak, Ja Hun; Szanyi, Janos; Cho, Sung June; Peden, Charles HF

2008-02-28

122

Precipitation Recycling  

NASA Technical Reports Server (NTRS)

The water cycle regulates and reflects natural variability in climate at the regional and global scales. Large-scale human activities that involve changes in land cover, such as tropical deforestation, are likely to modify climate through changes in the water cycle. In order to understand, and hopefully be able to predict, the extent of these potential global and regional changes, we need first to understand how the water cycle works. In the past, most of the research in hydrology focused on the land branch of the water cycle, with little attention given to the atmospheric branch. The study of precipitation recycling which is defined as the contribution of local evaporation to local precipitation, aims at understanding hydrologic processes in the atmospheric branch of the water cycle. Simply stated, any study on precipitation recycling is about how the atmospheric branch of the water cycle works, namely, what happens to water vapor molecules after they evaporate from the surface, and where will they precipitate?

Eltahir, Elfatih A. B.; Bras, Rafael L.

1996-01-01

123

TCA precipitation.  

PubMed

Trichloroacetic acid (TCA) precipitation of proteins is commonly used to concentrate protein samples or remove contaminants, including salts and detergents, prior to downstream applications such as SDS-PAGE or 2D-gels. TCA precipitation denatures the protein, so it should not be used if the protein must remain in its folded state (e.g., if you want to measure a biochemical activity of the protein). PMID:24674058

Koontz, Laura

2014-01-01

124

Abundance Analysis of Barium Stars  

E-print Network

We obtain the chemical abundances of six barium stars and two CH subgiant stars based on the high signal-to-noise ratio and high resolution Echelle spectra. The neutron capture process elements Y, Zr, Ba, La, Eu show obvious overabundance relative to the Sun, for example, their [Ba/Fe] values are from 0.45 to 1.27. Other elements, including Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Ni, show comparable abundances to the Solar ones, and their [Fe/H] cover a range from $-$0.40 to 0.21, which means they belong to Galactic disk. The predicts of the theoretical model of wind accretion for binary systems can explain the observed abundance patterns of the neutron capture process elements in these stars, which means that their overabundant heavy-elements could be caused by accreting the ejecta of AGB stars, the progenitors of the present white dwarf companions in the binary systems.

G. Q. Liu; Y. C. Liang; L. Deng

2008-11-13

125

Barium Isotopes in Single Presolar Grains  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

126

Pulsating aurora induced by upper atmospheric barium releases  

NASA Technical Reports Server (NTRS)

The paper reports the apparent generation of pulsating aurora by explosive releases of barium vapor near 250 km altitude. This effect occurred only when the explosions were in the path of precipitating electrons associated with the visible aurora. Each explosive charge was a standard 1.5 kg thermite mixture of Ba and CuO with an excess of Ba metal which was vaporized and dispersed by the thermite explosion. Traces of Sr, Na, and Li were added to some of the charges, and monitoring was achieved by ground-based spectrophotometric observations. On March 28, 1976, an increase in emission at 5577 A and at 4278 A was observed in association with the first two bursts, these emissions pulsating with roughly a 10 sec period for approximately 60 to 100 sec after the burst.

Deehr, C.; Romick, G.

1977-01-01

127

Preparation and Characterization of Nano-particle Substituted Barium Hexaferrite  

E-print Network

High density magnetic recording requires high coercivity magnetic media and small particle size. Barium hexaferrite has been considered as a leading candidate material because of its chemical stability, fairly large crystal anisotropy and suitable magnetic characteristics. In this work, we present the preparation of the hexagonal ferrite BaFe12O19 and one of its derivative; the Zn-Sn substituted hexaferrite by the chemical co-precipitation method. The main advantage of this method on the conventional glass-ceramic one, resides in providing a small enough particle size for magnetic recording. We demonstrate using the X-ray diffraction patterns that the particle size decreases when substituting the hexaferrite by the Zn-Sn combination. This may improve the magnetic properties of the hexaferrite as a medium for HD magnetic recording

Atassi, Yomen; Tally, Mohammad

2014-01-01

128

Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods. 4. Artificial aging of model samples of co-precipitates of lead chromate and lead sulfate.  

PubMed

Previous investigations about the darkening of chrome yellow pigments revealed that this form of alteration is attributable to a reduction of the original Cr(VI) to Cr(III), and that the presence of sulfur-containing compounds, most often sulfates, plays a key role during this process. We recently demonstrated that different crystal forms of chrome yellow pigments (PbCrO(4) and PbCr(1-x)S(x)O(4)) are present in paintings by Vincent van Gogh. In the present work, we show how both the chemical composition and the crystalline structure of lead chromate-based pigments influence their stability. For this purpose, oil model samples made with in-house synthesized powders of PbCrO(4) and PbCr(1-x)S(x)O(4) were artificially aged and characterized. We observed a profound darkening only for those paint models made with PbCr(1-x)S(x)O(4), rich in SO(4)(2-) (x ? 0.4), and orthorhombic phases (>30 wt %). Cr and S K-edge micro X-ray absorption near edge structure investigations revealed in an unequivocal manner the formation of up to about 60% of Cr(III)-species in the outer layer of the most altered samples; conversely, independent of the paint models' chemical composition, no change in the S-oxidation state was observed. Analyses employing UV-visible diffuse reflectance and Fourier transform infrared spectroscopy were performed on unaged and aged model samples in order to obtain additional information on the physicochemical changes induced by the aging treatment. PMID:23051631

Monico, Letizia; Janssens, Koen; Miliani, Costanza; Van der Snickt, Geert; Brunetti, Brunetto Giovanni; Cestelli Guidi, Mariangela; Radepont, Marie; Cotte, Marine

2013-01-15

129

Dielectric and Piezoelectric Properties of Barium Titanate  

Microsoft Academic Search

The dielectric constant and loss of barium titanate and barium-strontium titanate have been measured at biasing field strengths from 0 to 5 megavolts per meter, at temperatures from -50°C to +135°C and at frequencies from 0.1 to 25 megacycles. The measurements versus temperature indicate the expected agreement with the Curie-Weiss law at temperatures above the Curie point. Measurements versus field

Shepard Roberts

1947-01-01

130

Fabrication of Barium Ferrite Thick Films  

Microsoft Academic Search

During recent years the need for high quality self-biased barium ferrite (BaFe12O19) thick films had been increasing due to its chemical stability, anisotropy and oriented hexagonal M-type ferrites. Our goal is to fabricate barium ferrite thick films to be incorporated in self-biased microwave devises. Different methods such as sputtering, pulse laser deposition, CVD and modified liquid phase deposition have been

Wei Jiang Yeh; Carla Blengeri-Oyarce; Sundeep Pillamari; Jnana Manoj Appikonda; Laura Diaz; Yanko Kranov; David McIlroy

2008-01-01

131

Barium hexaferrite synthesis by oxalate precursor route  

Microsoft Academic Search

Magnetic materials are important electronic materials that have a wide range of industrial and commercial applications. Barium hexaferrite (BaFe12O19), is of great importance as permanent magnets, particularly for magnetic recording as well as in microwave devices. An aim of this study was to synthesize stoichiometric and single phase barium hexaferrite by a technique of oxalate precursor. Effect of different annealing

Q. Mohsen

2010-01-01

132

Assessment of Barium Sulphate Formation and Inhibition at Surfaces with Synchrotron X-ray Diffraction (SXRD)  

SciTech Connect

The precipitation of barium sulphate from aqueous supersaturated solutions is a well-known problem in the oil industry often referred to as 'scaling'. The formation and growth of barite on surfaces during the oil extraction process can result in malfunctions within the oil facilities and serious damage to the equipment. The formation of barium sulphate at surfaces remains an important topic of research with the focus being on understanding the mechanisms of formation and means of control. In situ synchrotron X-ray diffraction (SXRD) was used to investigate the formation of barium sulphate on a stainless steel surface. The effect of Poly-phosphinocarboxylic acid (PPCA) and Diethylenetriamine-penta-methylenephosphonic acid (DETPMP) which are two commercial inhibitors for barium sulphate was examined. The in situ SXRD measurements allowed the identification of the crystal faces of the deposited barite in the absence and presence of the two inhibitors. The preferential effect of the inhibitors on some crystal planes is reported and the practical significance discussed.

E Mavredaki; A Neville; K Sorbie

2011-12-31

133

Mine water treatment with limestone for sulfate removal.  

PubMed

Limestone can be an option for sulfate sorption, particularly from neutral mine drainages because calcium ions on the solid surface can bind sulfate ions. This work investigated sulfate removal from mine waters through sorption on limestone. Continuous stirred-tank experiments reduced the sulfate concentration from 588.0mg/L to 87.0mg/L at a 210-min residence time. Batch equilibrium tests showed that sulfate loading on limestone can be described by the Langmuir isotherm, with a maximum loading of 23.7mg/g. Fixed-bed experiments were utilized to produce breakthrough curves at different bed depths. The Bed Depth Service Time (BDST) model was applied, and it indicated sulfate loadings of up to 20.0gSO(4)(2-)/L-bed as the flow rate increased from 1 to 10mL/min. Thomas, Yoon-Nelson and dose-response models, predicted a maximum particle loading of 19mg/g. Infrared spectrometry indicated the presence of sulfate ions on the limestone surface. Sulfate sorption on limestone seems to be an alternative to treating mine waters with sulfate concentrations below the 1200-2000mg/L range, where lime precipitation is not effective. In addition, this approach does not require alkaline pH values, as in the ettringite process. PMID:22541641

Silva, Adarlêne M; Lima, Rosa M F; Leão, Versiane A

2012-06-30

134

Precipitation hardening  

NASA Astrophysics Data System (ADS)

The topic of precipitation hardening is critically reviewed, emphasizing the influence of precipitates on the CRSS or yield strength of aged alloys. Recent progress in understanding the statistics of dislocation-precipitate interactions is highlighted. It is shown that Pythagorean superposition for strengthening by random mixtures of localized obstacles of different strengths is rigorously obeyed in the limit of very weak obstacles; this had been known previously as a result of computer simulation experiments. Some experimental data are discussed in light of this prediction. All of the currently viable mechanisms of precipitation hardening are reviewed. It is demonstrated that all versions of the theory of coherency hardening are woefully inadequate, while the theory of order hardening is capable of accurately predicting the contribution of ?' precipitates to the CRSS of aged Ni-Al alloys. It is also convincingly shown that a new theory based on computer simulation experiments of the motion of dislocations through arrays of obstacles having a finite range of interaction cannot explain these same data, and is of doubtful validity in other instances for which its success has been proclaimed. A new theory of hardening by spinodal decomposition is proposed. It is based on the statistics of interaction between dislocations and diffuse attractive obstacles, and is shown to be in very good quantitative agreement with much of the limited data available. Some of the problems that remain to be addressed and solved are discussed.

Ardell, A. J.

1985-12-01

135

Roles of Heparan Sulfate Sulfation in Dentinogenesis*  

PubMed Central

Cell surface heparan sulfate (HS) is an essential regulator of cell signaling and development. HS traps signaling molecules, like Wnt in the glycosaminoglycan side chains of HS proteoglycans (HSPGs), and regulates their functions. Endosulfatases Sulf1 and Sulf2 are secreted at the cell surface to selectively remove 6-O-sulfate groups from HSPGs, thereby modifying the affinity of cell surface HSPGs for its ligands. This study provides molecular evidence for the functional roles of HSPG sulfation and desulfation in dentinogenesis. We show that odontogenic cells are highly sulfated on the cell surface and become desulfated during their differentiation to odontoblasts, which produce tooth dentin. Sulf1/Sulf2 double null mutant mice exhibit a thin dentin matrix and short roots combined with reduced expression of dentin sialophosphoprotein (Dspp) mRNA, encoding a dentin-specific extracellular matrix precursor protein, whereas single Sulf mutants do not show such defective phenotypes. In odontoblast cell lines, Dspp mRNA expression is potentiated by the activation of the Wnt canonical signaling pathway. In addition, pharmacological interference with HS sulfation promotes Dspp mRNA expression through activation of Wnt signaling. On the contrary, the silencing of Sulf suppresses the Wnt signaling pathway and subsequently Dspp mRNA expression. We also show that Wnt10a protein binds to cell surface HSPGs in odontoblasts, and interference with HS sulfation decreases the binding affinity of Wnt10a for HSPGs, which facilitates the binding of Wnt10a to its receptor and potentiates the Wnt signaling pathway, thereby up-regulating Dspp mRNA expression. These results demonstrate that Sulf-mediated desulfation of cellular HSPGs is an important modification that is critical for the activation of the Wnt signaling in odontoblasts and for production of the dentin matrix. PMID:22351753

Hayano, Satoru; Kurosaka, Hiroshi; Yanagita, Takeshi; Kalus, Ina; Milz, Fabian; Ishihara, Yoshihito; Islam, Md. Nurul; Kawanabe, Noriaki; Saito, Masahiro; Kamioka, Hiroshi; Adachi, Taiji; Dierks, Thomas; Yamashiro, Takashi

2012-01-01

136

Wnts, Signaling and Sulfates  

NSDL National Science Digital Library

Questions remain about the signaling pathways that control pattern formation during development. Blair describes how sulfated glycosaminoglycans affect several developmentally important signaling pathways, including Wnt-Wingless, Fibroblast growth factor, Hedgehog, and Bone morphogenetic protein-4 signaling. A new secreted sulfatase, Qsulf1, regulates the sensitivity of vertebrate cells to Wnts, possibly by modifying the sulfation of glycosaminoglycans.

Seth S. Blair (University of Wisconsin;Department of Zoology REV)

2001-09-25

137

Chemical composition of atmospheric precipitation in the northwestern United States  

Microsoft Academic Search

Data from sampling stations in the Northeastern United States show that atmosperic precipitation in this region is composed of a dilute calcium-hydrogen sulfate water having additional sodium and chloride near the coast. In the inland and coastal sections, excepting only the highly industrialized areas, variations among the precipitation chemical loads measured at various sites show no systematic differences that suggest

F. J. Jr. Pearson; D. W. Fisher

1971-01-01

138

Roles of Pt and BaO in the Sulfation of Pt/BaO/Al2O3 Lean NOx Trap Materials: Sulfur K-edge XANES and Pt Llll XAFS Studies  

SciTech Connect

The roles of barium oxide and platinum during the sulfation of Pt-BaO/Al2O3 lean NOx trap catalysts were investigated by S K edge XANES (X-ray absorption near-edge spectroscopy) and Pt LIII XAFS (X-ray absorption fine structure). All of the samples studied [Al2O3, BaO(x; x = 8 or 20 wt %)/Al2O3, Pt(2.5 wt %)/Al2O3, and Pt(2 wt %)-BaO(x; x = 8 or 20 wt %)/Al2O3] were pre-sulfated prior to the X-ray absorption measurements. It was found that barium oxide itself has the ability to directly form barium sulfate even in the absence of Pt and gas-phase oxygen. In the platinum-containing samples, the presence of Pt-O species plays an important role in the formation of sulfate species. For the case of the BaO(8)/Al2O3 sample, where the barium coverage is about 0.26 ML, both baria and alumina phases are available for sulfation. S XANES results show that barium sulfates are formed preferentially over aluminum sulfates. When oxygen is absent from the gas phase, the sulfation route that involves Pt-O is eliminated after the initially present Pt-O species are completely consumed. In this case, formation of sulfates is suppressed unless barium oxide is also present. Pt LIII XAFS results show that the first coordination sphere around the Pt atoms in the Pt particles is dependent upon the gas mixture used during the sulfation process. Sulfation under reducing environments (e.g., SO2/H2) leads to formation of Pt-S bonds, while oxidizing conditions (e.g., SO2/O2) continue to show the presence of Pt-O bonds. In addition, a reducing environment was found to cause Pt sintering in greater extent than an oxidizing one. This result explains why samples sulfated under reducing conditions had lower NOx uptakes than those sulfated under oxidizing conditions. Therefore, our results provide needed information for the development of optimum practical operation conditions (e.g., sulfation or desulfation) for lean NOx trap catalysts that minimize deactivation by sulfur.

Kim,D.; Kwak, J.; Szanyi, J.; Cho, S.; Peden, C.

2008-01-01

139

Incorporation of /sup 35/S-sulfate and /sup 3/H-glucosamine into heparan and chondroitin sulfates during the cell cycle of B16-F10 cells  

SciTech Connect

Changes in glycosaminoglycan composition occurring during the cell cycle were determined in B16-F10 cells sorted flow cytometrically with respect to DNA content. Incorporation of /sup 35/S-sulfate into heparan sulfate and chondroitin sulfate of unsorted and G1,S, and G2 +M sorted cells was determined following chondroitinase ABC or nitrous acid treatment; the incorporation into surface material was measured as the difference between the radioactivity of control and trypsin-treated cells. Incorporation of /sup 35/S-sulfate and /sup 3/H-glucosamine into cetyl pyridinium chloride (CPC)-precipitable material was characterized before and after chondroitinase or nitrous acid treatment by Sephadex G50 chromatography. Long-term (48 h) and short-term (1 h) labeling studies demonstrate that (a) the amount of total cellular chondroitin sulfate is greater than that of heparan sulfate, with larger amounts of unsulfated heparan than chondroitin being present; (b) the rate of turnover of heparan sulfate is greater than that of chondroitin sulfate; (c) greatest short-term incorporation of 3H-glucosamine into CPC-precipitable material occurs during S phase; and (d) the rate of turnover of both heparan sulfate and chondroitin sulfate is decreased in S phase relative to G1 and G2 + M.

Blair, O.C.; Sartorelli, A.C.

1984-05-01

140

Precipitation Gage  

USGS Multimedia Gallery

During August 2013, the Beaver Creek wildfire burned more than 114,000 acres near the south-central Idaho communities of Sun Valley, Ketchum, and Hailey. Partnering with Blaine County, the USGS installed a network of real-time precipitation gages in the burn area. Real-time information from the gage...

141

Removal of sulfate from high-strength wastewater by crystallisation.  

PubMed

Sulfate causes considerable problems in anaerobic digesters, related to generation of sulfides, loss of electrons (and hence methane), and contamination of gas streams. Removal of sulfides is generally expensive, and still results in methane losses. In this paper, we evaluate the use of precipitation for low-cost sulfate removal, in highly contaminated streams (>1 gS L(-1)). The main precipitate assessed is calcium sulfate (gypsum), though the formation of complex precipitates such as jarosite and ettringite to remove residual sulfate is also evaluated. The four main concerns in contaminated wastewater are:- high solubility, caused by high ion activity and ion pairing; slow kinetics; inhibition of nucleation; and poisoning of crystals by impurities, rendering product unsuitable for reuse as seed. These concerns were addressed through batch experiments on a landfill wastewater with a similar composition to other sulfate rich industrial wastewaters (high levels of organic and inorganic contaminants). Crystallisation rates were rapid and comparable to what is observed by others for pure solutions (2-5 h). The kinetics of crystallisation showed a 2nd order dependence on supersaturation, which have implications for crystalliser design, as discussed in the paper. No spontaneous nucleation was observed (seed was required). Seed poisoning did not occur, and product crystals were as effective as pure seed. Solubility was increased by an order of magnitude compared to a pure solution (2.6x10(-3) M2 vs. 0.22x10(-3) M2). As evaluated using equilibrium modelling, this was caused equally by non-specific ion activity, and specific ion pairing. Jarosite and ettringite could not be formed at reasonable pH and temperature levels. Given the lack of complex precipitates, and relatively high solubility, gypsum crystallisation cannot practically be used to remove sulfate to very low levels, and gas-sulfide treatment will likely still be required. It can however, be used for low-cost bulk removal of sulfate. PMID:19059623

Tait, Stephan; Clarke, William P; Keller, Jurg; Batstone, Damien J

2009-02-01

142

Temperature-dependent coherent oscillation in photorefractive relaxor strontium barium  

E-print Network

Temperature-dependent coherent oscillation in photorefractive relaxor strontium barium niobate M of the photorefractive light-induced scattering (beam fanning) in Sr0.61Ba0.39Nb2O6 (strontium barium niobate) doped

Osnabrück, Universität

143

An assessment of the redistribution of Barium during diagenesis of Marcellus Shale  

NASA Astrophysics Data System (ADS)

Produced water from the hydrofracturing of Marcellus Shale have been reported to contain barium at concentrations >4000 ppm (Gregory et al, 2011). Understanding the reactions responsible for the leaching of Ba into produced water is important for improving the economic viability of gas extraction and to mitigate environmental concerns. Core samples of Marcellus Shale from New York and Pennsylvania were shown to contain Ba in the range of 400-2200 ?g/g. In some of these samples, barite (BaSO4) grains are shown to be partially replaced by pyrite (massive and framboidal varieties) suggesting that Ba is remobilized in the zone of sulfate reduction sometime after sedimentation. Sequential extraction experiments show Ba being released into buffered acetic acid (carbonate fraction), aqua regia (sulfide fraction), and hydrofluoric acid (silicate fraction) extractions despite ~50% of the barium remaining undissolved as barite. Laser ablation ICP-MS showed negligible concentrations of Ba in calcite veins and elevated concentrations in areas of the shale that are predominantly clay + organics. These results suggest that some of the Ba is associated with the clay fraction of the shale (e.g., sorbed to clay surfaces as a result of the anoxic dissolution of barite). These results may inform future strategies for mitigating the release of barium into produced water.

Renock, D.; Symcox, C.; Lanids, J. D.; Sharma, M.

2012-12-01

144

Two barium stars in the Galactic bulge  

E-print Network

Barium stars conserve important information on the s-process and the third dredge-up in intermediate mass stars. Their discovery in various environments is therefore of great help to test nucleosynthesis and mixing models. Our aim is to analyse two stars with a very strong barium line detected in a large survey of red giants in the Galactic bulge. Abundance analysis was done comparing synthetic model spectra based on the COMARCS code with our medium resolution spectra. Abundances of Ba, La, Y, and Fe were determined. Beside the two main targets, the analysis was also applied to two comparison stars. We confirm that both stars are barium stars. They are the first ones of this kind identified in the Galactic bulge. Their barium excesses are among the largest values found up to now. The elemental abundances are compared with current nucleosynthesis and mixing models. Furthermore, we estimate a frequency of barium stars in the Galactic bulge of about 1%, which is identical to the value for disc stars.

Lebzelter, Thomas; Straniero, Oscar; Aringer, Bernhard

2013-01-01

145

Two barium stars in the Galactic bulge  

NASA Astrophysics Data System (ADS)

Context. Barium stars conserve important information on the s-process and the third dredge-up in intermediate mass stars. Their discovery in various environments is therefore of great help in testing nucleosynthesis and mixing models. Aims: Our aim is to analyse two stars with a very strong barium line detected in a large survey of red giants in the Galactic bulge. Methods: Abundance analysis was done comparing synthetic model spectra based on the COMARCS code with our medium resolution spectra. Abundances of Ba, La, Y, and Fe were determined. Beside the two main targets, the analysis was also applied to two comparison stars. Results: We confirm that both stars are barium stars. They are the first ones of this kind identified in the Galactic bulge. Their barium excesses are among the largest values found up to now. The elemental abundances are compared with current nucleosynthesis and mixing models. Furthermore, we estimate a frequency of barium stars in the Galactic bulge of about 1%, which is identical to the value for disc stars. Based on observations at the Very Large Telescope of the European Southern Observatory, Cerro Paranal/Chile, under Programme 083.D-0046(A).

Lebzelter, T.; Uttenthaler, S.; Straniero, O.; Aringer, B.

2013-06-01

146

Calcium Sulfate Formation and Mitigation when Seawater was Used to Prepare HCl-Based Acids  

E-print Network

with sulfate ion in seawater (greater than 3000 ppm) and calcium sulfate will precipitate once it exceeds its critical scaling tendency. A few studies have provided evidence for this problem and how to address this problem has not been fully examined. Core...

He, Jia

2012-02-14

147

Selective total encapsulation of the sulfate anion by neutral nano-jars.  

PubMed

Nano-sized toroidal copper(II)-hydroxide/pyrazolate assemblies, lined by H-bond donors on the inside and hydrophobic on the outside, selectively extract sulfate from mixtures with nitrate or perchlorate. Tetrabutylammonium "lids" seal the "nano-jars" and render the encapsulated sulfate anion completely buried and inaccessible, so that it is not precipitated by Ba(2+) ions. PMID:22669223

Fernando, Isurika R; Surmann, Stuart A; Urech, Alexander A; Poulsen, Alexander M; Mezei, Gellert

2012-07-11

148

Ferroelectric Properties of Individual Barium Titanate Nanowires Investigated  

E-print Network

Ferroelectric Properties of Individual Barium Titanate Nanowires Investigated by Scanned Probe on the ferroelectric properties of individual single-crystalline barium titanate nanowires. We show that nonvolatile report the scanned probe characterization of individual single-crystalline barium titanate (BaTiO3) nano

Heller, Eric

149

Magnetoresistive Conductive Polyaniline-Barium Titanate Nanocomposites with Negative Permittivity  

E-print Network

Magnetoresistive Conductive Polyaniline-Barium Titanate Nanocomposites with Negative Permittivity Carolina 28301, United States ABSTRACT: Polyaniline (PANI) polymer nanocomposites (PNCs) filled with barium field sensors,10 energy electrodes11 and biosensors.12,13 Barium titanate (BaTiO3) as transition metal

Guo, John Zhanhu

150

PHOTOSENSITIVE CENTERS AND CHARGE TRANSFER PROCESSES IN BARIUM CALCIUM TITANATE  

E-print Network

PHOTOSENSITIVE CENTERS AND CHARGE TRANSFER PROCESSES IN BARIUM CALCIUM TITANATE G.MALOVICHKO, V@uos.de; vgrachev@uos.de; schirmer@uos.de Abstract The results of the study of charge transfer processes in barium of crystals from barium titanate (BT) family make them promising candidates for various applications

Malovichko, Galina

151

Experiments with remote entanglement using single barium ions Nathan Kurz  

E-print Network

Experiments with remote entanglement using single barium ions Nathan Kurz A dissertation submitted entanglement using single barium ions Nathan Kurz Chair of the Supervisory Committee: Dr. Boris B. Blinov Physics Department Barium ion qubits are trapped and Doppler cooled in a linear Paul trap and the tasks

Blinov, Boris

152

Improved spectrophotometric analysis of barium styphnate  

SciTech Connect

A spectrophotometric procedure to determine the purity of barium styphnate monohydrate based upon the absorbance of the styphnate ion at 326 and 413.3 nm has been developed. The purity is determined by comparing the absorbance of the styphnate ion in barium styphnate and in styphnic acid. Our investigation has shown that the molar absorptivity and lambda maxima of the styphnate ion are quite pH dependent; therefore, the pH is buffered to 6.8 to 7.0 with ammonium acetate. Under these conditions the molar absorptivity is 1.6 x 10/sup 4/ L/mol-cm. Analyses following the procedure in the Navy specification WS13444A using water were found to give low molar absorptivities (1.3 x 10/sup 4/ L/mol-cm) for the styphnic acid calibration resulting in erroneous values for barium styphnate purity.

Brown, N E; Blasi, J A

1983-01-01

153

Measuring Precipitation  

NSDL National Science Digital Library

Students will design, build and then test a rain gauge to measure precipitation. By sharing their results, they will recognize the need for standardization and precision in scientific tools. All background information, student worksheets and images/photographs/data are included in these downloadable sections: Teacher’s Guide, Student Capture Sheet and PowerPoint Presentation. This activity uses the 5E instructional model and is part of the Survivor Earth series of one-hour lessons.

154

Acidic precipitation  

SciTech Connect

The authors present an overview of the environmental chemistry and transport phenomena of air pollutants, biological and ecological effects of acidic precipitation, mitigation of acidified aquatic ecosystems, and modelling approaches. This book reviews what is known about the impact of acidic deposition in the biota and processes in complex ecosystems such as lakes, streams, and forests. The specific effects on crops, trees, fish, and microorganisms are also discussed.

Adriano, D.C. (Georgia Univ., Aiken, SC (USA)); Johnson, A.H. (Pennsylvania Univ., Philadelphia, PA (USA))

1989-01-01

155

Hydrazine Sulfate (PDQ®)  

Cancer.gov

Expert-reviewed information summary about the use of hydrazine sulfate as a treatment for people with cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

156

Holothurian Fucosylated Chondroitin Sulfate  

PubMed Central

Fucosylated chondroitin sulfate (FucCS) is a structurally distinct glycosaminoglycan found in sea cucumber species. It has the same backbone composition of alternating 4-linked glucuronic acid and 3-linked N-acetyl galactosamine residues within disaccharide repeating units as regularly found in mammalian chondroitin sulfates. However, FucCS has also sulfated fucosyl branching units 3-O-linked to the acid residues. The sulfation patterns of these branches vary accordingly with holothurian species and account for different biological actions and responses. FucCSs may exhibit anticoagulant, antithrombotic, anti-inflammatory, anticancer, antiviral, and pro-angiogenic activities, besides its beneficial effects in hemodialysis, cellular growth modulation, fibrosis and hyperglycemia. Through an historical overview, this document covers most of the science regarding the holothurian FucCS. Both structural and medical properties of this unique GAG, investigated during the last 25 years, are systematically discussed herein. PMID:24413804

Pomin, Vitor H.

2014-01-01

157

RELATING GAS HYDRATE SATURATION TO DEPTH OF SULFATE METHANE TRANSITION  

Microsoft Academic Search

Gas hydrate can precipitate in pore space of marine sediment when gas concentrations exceed solubility conditions within a gas hydrate stability zone (GHSZ). Here we present analytical expressions that relate the top of the GHSZ and the amount of gas hydrate within the GHSZ to the depth of the sulfate-methane transition (SMT). The expressions are strictly valid for steady-state systems

Gaurav Bhatnagar; Walter G. Chapman; George J. Hirasaki; Gerald R. Dickens; Brandon Dugan

158

Glycopeptide Sulfation Evades Resistance  

PubMed Central

The incidence of antibiotic resistance among pathogenic microorganisms is increasing at an alarming rate. Resistance against front-line therapeutics such as the glycopeptide antibiotic vancomycin has emerged and has spread to highly virulent pathogens, including Staphylococcus aureus. Glycopeptide antibiotics are natural products from the Actinomycetes that have a characteristic heptapeptide core. The chemical diversity of the class is achieved through glycosylation, halogenation, methylation, and acylation of the core, modifications that are implicated in improved solubility, stability, or activity of the molecule. Sulfation is yet another modification observed infrequently in glycopeptides, but its role is not known. Although glycopeptide sulfotransferases are found in the environmental metagenome and must therefore serve an evolutionary purpose, all previous studies have reported decreased antibiotic activity with sulfation. We report that sulfation of glycopeptides has little effect on the compound's ability to bind its target, the d-Ala-d-Ala peptidoglycan precursors of the bacterial cell wall. However, sulfation does impact glycopeptide dimerization, and importantly, sulfated glycopeptides are significantly less potent inducers of the resistance gene cluster vanHAX in actinomycetes. Our results begin to unravel the mystery of the biological role of glycopeptide sulfation and offer a potential new strategy for the development of new antibiotics that avoid resistance. PMID:23104813

Kalan, Lindsay; Perry, Julie; Koteva, Kalinka; Thaker, Maulik

2013-01-01

159

Barium Titanate and Bismuth Oxide Nanocomposites Barium titanate, BaTiO3, and bismuth oxide Bi2O3 are transparent materials with  

E-print Network

Barium Titanate and Bismuth Oxide Nanocomposites Barium titanate, BaTiO3, and bismuth oxide Bi2O3 Wall in Tetragonal Barium Titanate", H. Chaib, F. Schlaphof, T. Otto and L. M. Eng, Journal of Physics

Harmon, Julie P.

160

Stoichiometry : PrecipYield (3 Variations)  

NSDL National Science Digital Library

In a laboratory experiment to determine accurately the amount of barium in solution, aqueous sulfuric acid was added to the solution to precipitate barium sulfate, which was then filtered and weighed. In this experiment it is MOST important that ...

161

Analysis of 26 Barium Stars I. Abundances  

E-print Network

We present a detailed analysis of 26 barium stars, including dwarf barium stars, providing their atmospheric parameters (Teff, log g, [Fe/H], vt) and elemental abundances. We aim at deriving gravities and luminosity classes of the sample stars, in particular to confirm the existence of dwarf barium stars. Accurate abundances of chemical elements were derived. Abundance ratios between nucleosynthetic processes, by using Eu and Ba as representatives of the r- and s-processes are presented. High-resolution spectra with the FEROS spectrograph at the ESO-1.5m Telescope, and photometric data with Fotrap at the Zeiss telescope at the LNA were obtained. The atmospheric parameters were derived in an iterative way, with temperatures obtained from colour-temperature calibrations. The abundances were derived using spectrum synthesis for Li, Na, Al, alpha-, iron peak, s- and r-elements atomic lines, and C and N molecular lines. Atmospheric parameters in the range 4300 barium stars, were derived and showed that [X/Ba] vs. [Ba/H] and [X/Ba] vs. [Fe/H] present different behaviour as compared to [X/Eu] vs. [Eu/H] and [X/Eu] vs. [Fe/H], reflecting the different nucleosynthetic sites for the s- and r-processes.

Dinah M. Allen; Beatriz Barbuy

2006-04-03

162

STABILIZED BARIUM TITANATE CERAMICS FOR CAPACITOR DIELECTRICS  

Microsoft Academic Search

The effects of additions of LaâOâ and LaâOâ--; 3TiOâ on the electronic properties of barium titanate were investigated. ; It was found that small additions of the components markedly increase the ; lifetime of the material subjected to d-c fields of 50 v per mil at 200 l ; C. (auth);

J. B. MacChesney; P. K. Gallagher; F. V. DiMarcello

1963-01-01

163

Effect of Ni(OH) 2 coating on the electromagnetic properties of hexagonal barium ferrite  

Microsoft Academic Search

Barium ferrite (BaF), BaFe12O19, was successfully prepared by a sol–gel self-propagating high-temperature synthesis (SHS) method, and the BaF sample was coated with nickel hydroxide through a coordination–precipitation method (Ni(OH)2\\/BaF). Nickel hydroxide was determined in Ni(OH)2\\/BaF by energy dispersive X-ray analysis (EDAX), though no diffraction peaks of nickel hydroxide was detected by XRD. BaF and Ni(OH)2\\/BaF both show single magnetic domain

P. Xu; X. J. Han; X. H. Wang; C. Wang; H. T. Zhao; W. J. Zhang

2008-01-01

164

Evidence of a paracellular pathway for ion flow in the kidney proximal tubule: Electromicroscopic demonstration of lanthanum precipitate in the tight junction  

Microsoft Academic Search

In the doubly perfused toad kidney, lanthanum ions were included in the perfusion fluid in a soluble form and were subsequently precipitated as anthanum sulfate. The precipitate was localized by electronmicroscopy.

G. WIIITTEMBURY; F. A. Rawlins

1971-01-01

165

Sulfate attack expansion mechanisms  

SciTech Connect

A specially constructed stress cell was used to measure the stress generated in thin-walled Portland cement mortar cylinders caused by external sulfate attack. The effects of sulfate concentration of the storage solution and C{sub 3}A content of the cement were studied. Changes in mineralogical composition and pore size distribution were investigated by X-ray diffraction and mercury intrusion porosimetry, respectively. Damage is due to the formation of ettringite in small pores (10–50 nm) which generates stresses up to 8 MPa exceeding the tensile strength of the binder matrix. Higher sulfate concentrations and C{sub 3}A contents result in higher stresses. The results can be understood in terms of the effect of crystal surface energy and size on supersaturation and crystal growth pressure.

Müllauer, Wolfram, E-mail: wolf_m@gmx.at; Beddoe, Robin E.; Heinz, Detlef

2013-10-15

166

Precipitation chemistry in central Amazonia  

NASA Technical Reports Server (NTRS)

Rain samples from three sites in central Amazonia were collected over a period of 6 weeks during the 1987 wet season and analyzed for ionic species and dissolved organic carbon. A continuous record of precipitation chemistry and amount was obtained at two of these sites, which were free from local or regional pollution, for a time period of over 1 month. The volume-weighted mean concentrations of most species were found to be about a factor of 5 lower during the wet season compared with previous results from the dry season. Only sodium, potassium, and chloride showed similar concentrations in both seasons. When the seasonal difference in rainfall amount is taken into consideration, the deposition fluxes are only slightly lower for most species during the wet season than during the dry season, again with the exception of chloride, potassium, and sodium. Sodium and chloride are present in the same ratio as in sea salt; rapid advection of air masses of marine origin to the central Amazon Basin during the wet season may be responsible for the observed higher deposition flux of these species. Statistical analysis suggests that sulfate is, to a large extent, of marine (sea salt and biogenic) origin, but that long-range transport of combustion-derived aerosols also makes a significant contribution to sulfate and nitrate levels in Amazonian rain. Organic acid concentrations in rain were responsible for a large fraction of the observed precipitation acidity; their concentration was strongly influenced by gas/liquid interactions.

Andreae, M. O.; Talbot, R. W.; Berresheim, H.; Beecher, K. M.

1990-01-01

167

Bis(4-sulfamoylanilinium) sulfate  

PubMed Central

In the title salt, 2C6H9N2O2S+·SO4 2?, the sulfate S atom is situated on a crystallographic twofold axis (the symmetry of the anion is 2). The anion exerts intense libration, which is manifested by shortening of the observed sulfate S—O bonds, as well as by features in the electron-density map. The crystal structure is stabilized through a three-dimensional hydrogen-bonding network formed by strong N—H?O hydrogen bonds. PMID:23634124

Ravikumar, B.; Pandiarajan, S.; Athimoolam, S.

2013-01-01

168

Trapped Barium Ions for Quantum ComputationTrapped Barium Ions for Quantum Computation V.Mirgon, G.Shu, A.Avril, M.Dietrich N.Kurz, E. Shahar, and B.B.Blinov  

E-print Network

Trapped Barium Ions for Quantum ComputationTrapped Barium Ions for Quantum Computation V.Mirgon, G of Washington Seattle WA 98195 Trapped Barium Ions for Quantum ComputationTrapped Barium Ions for Quantum

Blinov, Boris

169

Sulfate could mediate the therapeutic effect of glucosamine sulfate  

Microsoft Academic Search

Glucosamine sulfate is a controversial osteoarthritis remedy that is presumed to stimulate articular cartilage glycosaminoglycan synthesis by increasing glucosamine concentrations in the joint space. However, this is not plausible because even large oral doses of the product have no effect on serum glucosamine concentrations. We propose instead that sulfate could mediate the clinical benefit attributed to this treatment. Sulfate is

L. John Hoffer; Ludmila N. Kaplan; Mazen J. Hamadeh; Ariadna C. Grigoriu; Murray Baron

2001-01-01

170

A Spectroscopic Analysis of Barium Stars  

NASA Astrophysics Data System (ADS)

Detailed abundance analyses have been carried out for 31 barium and normal G-K giant stars using high-dispersion spectra and model atmospheres. A significant enhancement of s-process elements is found for seventeen stars. The abundances of light and iron-peak elements are in general equal to those in the standard star ? Vir. However, Na, Mg, Mn, and Co are systematically slightly deficient (about 0.2 dex). The elements heavier than Ni are enhanced by up to about 1.5 dex compared with the standards, while the r-process element Eu abundance is roughly normal. We cannot find substantial differences in abundances, atmospheric parameters, and luminosities of radial- velocity variable and nonvariable barium stars. Therefore it seems that both groups of stars belong to a single family of peculiar giants. Comparison between the mean observed s-process abundances for our uniform barium star sample, and theoretical predictions from various neutron exposure models, show that 13C neutron source AGB star (with the mean neutron exposure ?0 > 0.4mb-1 can best reproduce the abundance data of these stars. Low neutron density single neutron exposures of approx. 1.1mb-1 also are shown to result in good agreement with the barium star observations. Mass transfer scenarios are tested using the chemical composition and orbital parameter data of Ba II stars. Since a correlation exists between s-process abundance anomalies and orbital periods (projections of the semi-major axis, mass functions) for barium star binaries, we conclude that a wind accretion scenario is more promising than Roche-lobe overflow ones. Abundance patterns for barium and carbon stars have been compared. We find good agreement for the iron group metals, but carbon stars show higher s-process element overabundances (0.9 dex in the mean). Therefore, the companions to the Ba II stars were perhaps once carbon stars, who overflowed mass onto the presently visible star with a second dilution (the ratio of the transferred mass to the mass of the receiving envelope) of roughly 0.9.

Zacs, L.

1994-03-01

171

Aluminum Sulfate 18 Hydrate  

ERIC Educational Resources Information Center

A chemical laboratory information profile (CLIP) of the chemical, aluminum sulfate 18 hydrate, is presented. The profile lists physical and harmful properties, exposure limits, reactivity risks, and symptoms of major exposure for the benefit of teachers and students using the chemical in the laboratory.

Young, Jay A.

2004-01-01

172

Synthesis and characterisation of ferrihydrite/silica co-precipitates.  

PubMed

The effect of the presence of soluble silicates on ferrihydrite precipitation and some properties of the products formed in co-precipitation of ferrihydrite and silica have been investigated. The co-precipitates were formed using a continuous crystallisation process in which a combined iron/silicon feed solution was reacted with sodium hydroxide at a constant rate, while maintaining pH at 2.65 and temperature at 85 degrees C. The products of co-precipitation and the supernatant solutions were characterised using a variety of analytical techniques including X-ray diffraction (XRD), transmission electron microscopy (TEM) and surface charge measurements. The addition of silicates was shown to have a significant impact on the crystallinity and surface charge of the precipitates formed. For products collected after five residence times in the continuous crystalliser, co-precipitates formed from ferric sulfate solution were found to contain considerably less silica than those formed from ferric nitrate. We conclude that adsorption of silicate species on ferrihydrite surfaces speeds up the polymerisation process, and that sulfate ion competes with silicate for surface adsorption sites. Thus, the precipitation of silica proceeds much more rapidly in ferric nitrate media, than in ferric sulfate. PMID:20466382

Dyer, Laurence; Fawell, Phillip D; Newman, O M G; Richmond, William R

2010-08-01

173

Ultrafast laser inscription of bistable and reversible waveguides in strontium barium niobate crystals  

E-print Network

Ultrafast laser inscription of bistable and reversible waveguides in strontium barium niobate optical channel waveguides in strontium barium niobate nonlinear ferroelectric crystals by direct barium niobate SBN crystal because of its prime importance in modern photonics due to its nonlinear

174

Enhanced dielectric properties from barium strontium titanate films with strontium titanate buffer layers  

E-print Network

Enhanced dielectric properties from barium strontium titanate films with strontium titanate buffer in their PE state. One of the leading material candidates for tunable materials is barium strontium titanate- tive amounts of Ba and Sr. TC for pure barium t

Alpay, S. Pamir

175

Dielectric properties of MgO-doped compositionally graded multilayer barium strontium titanate films  

E-print Network

Dielectric properties of MgO-doped compositionally graded multilayer barium strontium titanate shifters and filters operat- ing in the microwave regime.1­4 Ferroelectrics FEs such as barium strontium. Required amounts of barium

Alpay, S. Pamir

176

Engineering domain configurations for enhanced piezoelectricity in barium titanate single crystals  

E-print Network

Engineering domain configurations for enhanced piezoelectricity in barium titanate single crystals piezoelectric responses of barium titanate single crystals under different crystallographic orientations, and use it to explain the ultrahigh piezoelectric response recently observed in a 270 cut barium titanate

Li, Jiangyu

177

Mineralogy and autoradiography of selected mineral-spring precipitates in the Western United States  

USGS Publications Warehouse

X-ray diffaction analysis of 236 precipitate or sediment samples from 97 mineral-spring sites in nine Western States showed the presence of 25 minerals, some precipitated and some detrital. Calcite and (or) aragonite are the most common of all the precipitated minerals. Gypsum and (or) anhydrite, as well as barite and native sulfur, are less common but are also believed to be precipitated minerals. Precipitated manganese and iron oxides, including romanechite, manganite, pyrolusite, goethite, and hematite, were found in some of the samples. Various salts of sodium, including halite and thenardite, were also identified. Dolomite and an unknown type of siliceous material are present in some of the samples and were possibly precipitated at the spring sites. Quartz, feldspar, and mica are present in many of the samples and are believed to be detrital contaminants. An autoradiographic and thin section study of 11 samples from nine of the most radioactive spring sites showed the radioactivity, which is due primarily to radium, to be directly associated with mineral phases containing barium, manganese, iron, and (or) calcium as major constituents. Furthermore, the radioactivity has an exclusive affinity for the manganese-bearing minerals, which in these samples contain a substantial amount of barium, even if calcite or iron oxides are present. Where calcite predominates and manganese- and barium-bearing minerals are absent, the radioactivity shows a close association with the iron oxides present, especially hematite, but also shows a moderate association with the calcite and (or) aragonite cementing phases. In other samples composed predominantly of calcite but lacking iron oxides, the radioactivity is preferentially associated with an early stage of calcite development and is considerably lower in the later cementing stages. The radioactivity observed in all these samples is believed to be caused by radium substituting for barium in mineral lattices, filling irregularities in other crystal structures, or adsorbing on the surfaces of precipitated molecules.

Bove, Dana; Felmlee, J.K.

1982-01-01

178

Production of translationally cold barium monohalide ions  

E-print Network

We have produced sympathetically cooled barium monohalide ions BaX$^+$ (X = F, Cl, Br) by reacting trapped, laser cooled Ba$^+$ ions with room temperature gas phase neutral halogen-containing molecules. Reaction rates for two of these (SF$_6$ and CH$_3$Cl) have been measured and are in agreement with classical models. BaX$^+$ ions are promising candidates for cooling to the rovibrational ground state, and our method presents a straightforward way to produce these polar molecular ions.

DePalatis, M V

2013-01-01

179

Barium ferrite films grown by laser ablation  

Microsoft Academic Search

Pulsed laser ablation (PLA) has been used to grow barium ferrite films on Al2O3 single crystal substrates. When deposition occurs in an oxidising atmosphere at high temperatures, the films are single BaFe12O19 phase, very well oriented with (001) texture, and exhibit a large perpendicular magnetic anisotropy. In this case, the microstructure and the anisotropy orientation are not influenced by variation

A. Lisfia; J. C. Lodder; P. de Haan; M. A. Smithers; F. J. G. Roesthuis

1998-01-01

180

Properties of barium ferrite sputtered films  

Microsoft Academic Search

Ferrites have magnetic properties suitable for electronic applications, especially in the microwave range (circulators and isolators). Hexagonal ferrite, such as barium ferrite (BaFe12O19 or BaM), are of great interest for microwave device applications because of their large resistivity and high permeability at high frequencies. BaM films, 1–10?m thick, were deposited under optimized conditions by RF magnetron sputtering on alumina and

S. Capraro; M. Le Berre; J. P. Chatelon; H. Joisten; E. Mery; B. Bayard; J. J. Rousseau; D. Barbier

2004-01-01

181

Pyroelectroluminescence of barium beta borate single crystals  

Microsoft Academic Search

Investigations were made of the pyroluminescence properties of barium beta borate single crystals. The measurements were made\\u000a at air pressures of 1–10 Pa and temperatures of 80–400 K. Luminescence was observed as isolated flashes over the entire range\\u000a of experimental conditions. It was observed that the light flashes coincided with the pyrocurrent oscillations.

V. T. Adamiv; Ya. V. Burak; M. R. Panasyuk; I. M. Teslyuk

1998-01-01

182

Electronic structure of nanograin barium titanate ceramics  

Microsoft Academic Search

The density of states and band structure of 20 nm barium titanate (BaTiO3, BT) ceramics are investigated by first-principles calculation. The full potential linearized augmented plane wave (FLAPW)\\u000a method is used and the exchange correlation effects are treated by the generalized gradient approximation (GGA). The results\\u000a show that there is substantial hybridization between the Ti 3d and O 2p states

Xiangyun Deng; Xiaohui Wang; Dejun Li; Longtu Li

2007-01-01

183

Resonance-fluorescence in barium ion clouds  

NASA Astrophysics Data System (ADS)

The problem of resonant-fluorescent scattering of sunlight by a high altitude, plane-parallel, barium ion cloud is solved numerically. Line strengths and profiles are computed using a modified version of the computer program LINEAR (Auer, Heasley and Milkey, 1972). Hyperfine structure of the spectral lines becomes important for very thick layers and is taken into account. Comparisons are made between coherent and completely noncoherent scattering results, and finally the influence of collisions on the radiation field is estimated.

Horak, H. G.; Whitaker, R. W.

1982-09-01

184

Polymorphic change from vaterite to aragonite under influence of sulfate: The "morning star" habit  

NASA Astrophysics Data System (ADS)

The presence of sulfate in reverse osmosis drinking water concentrate and its effect on calcium carbonate precipitation was studied, notably the overall kinetics of CaCO3 formation and the types of polymorphs formed. CaCO3 formation slows down with increasing sulfate concentration and the preferential polymorph shifts from vaterite to aragonite with increasing sulfate concentration. With this polymorphic change, a new combined habit is observed where aragonite spikes grow on top of vaterite ("morning star" habit). The presence of a moderate magnesium concentration results in the shift of vaterite to aragonite at relatively low sulfate concentrations; where sulfate and magnesium appear to have an additive effect. Without magnesium, spikes on top of vaterite were also observed, but only at relatively high sulfate concentration. Without the presence of magnesium, single crystals of aragonite were not found.

Wagterveld, R. M.; Yu, M.; Miedema, H.; Witkamp, G. J.

2014-02-01

185

Fabrication of Barium Ferrite Thick Films  

NASA Astrophysics Data System (ADS)

During recent years the need for high quality self-biased barium ferrite (BaFe12O19) thick films had been increasing due to its chemical stability, anisotropy and oriented hexagonal M-type ferrites. Our goal is to fabricate barium ferrite thick films to be incorporated in self-biased microwave devises. Different methods such as sputtering, pulse laser deposition, CVD and modified liquid phase deposition have been used for thick film deposition with limited or no success for thickness above 300?m. Excessive residual stresses of BaM films deposited with the previous methods and/or their low coercivity are the main problems targeted by this project. We present a low cost solution using BaFe12O19 nanopowder mixing with epoxy. The mix is placed on alumina substrates to fabricate 500?m thick films of BaM, resulting thick films with good magnetic properties such as a 4?Ms between 2.000 to 2.500 Gauss and a coercivity of 3800 to 4000 Oe. In addition, we have integrated the barium ferrite thick films into microwave devises and successfully deposited their contact lines for their testing and use.

Jiang Yeh, Wei; Blengeri-Oyarce, Carla; Pillamari, Sundeep; Manoj Appikonda, Jnana; Diaz, Laura; Kranov, Yanko; McIlroy, David

2008-05-01

186

Creating unstable velocity-space distributions with barium injections  

NASA Technical Reports Server (NTRS)

Ion velocity-space distributions resulting from barium injections from orbiting spacecraft and shaped charges are discussed. Active experiments confirm that anomalous ionization processes may operate, but photoionization accounts for the production of the bulk of the barium ions. Pitch-angle diffusion and/or velocity-space diffusion may occur, but observations of barium ions moving upwards against gravity suggests that the ions retain a significant enough fraction of their initial perpendicular velocity to provide a mirror force. The barium ion plasmas should have a range of Alfven Mach numbers and plasma betas. Because the initial conditions can be predicted these active experiments should permit testing plasma instability hypotheses.

Pongratz, M. B.

1983-01-01

187

Tests of the use of net throughfall sulfate to estimate dry and occult sulfur deposition  

NASA Astrophysics Data System (ADS)

Throughfall and stemflow measurements taken in a mature high elevation red spruce stand, and precipitation measurements made in a nearby clearing, were used to calculate weekly net throughfall (=throughfall + stemflow - precipitation) sulfate deposition and net throughfall volume in the stand over a 20-week period. The study fortuitously was divisible into a low cloudwater deposition period, during which precipitation volumes generally exceeded throughfall volumes, and a high cloud period, during which the reverse was true. Weekly cloudwater deposition volume was estimated independently from continuously recorded cloudwater collections by an artificial tree located on an elevated platform in the clearing. Weekly net throughfall volume correlated well with cloudwater deposition volume ( r = +0.86). Precipitation accounted for only 25% of the throughfall sulfate collected throughout the study and only 15% of that collected during the high cloud period, as net throughfall sulfate was 2.4 times greater during the high cloud period than during the low cloud period. Weekly estimates of cloudwater sulfate deposition correlated well ( r = +0.74) with measures of net throughfall sulfate during the high cloud period. Dry deposition models were used to estimate weekly dry S deposition; weekly estimates of the wash-off of this dry deposition also correlated well ( r = +0.76) with net throughfall sulfate during the low cloud period. During the high cloud period, estimates of cloudwater S plus dry S deposition accounted for 67% of the sulfate collected in net throughfall; however, during the low cloud period only 55% of net throughfall sulfate was accounted for. The low percentage of sulfate accounted for during the low cloud period suggests that the dry models were underestimating S deposition. Possible reasons for underestimation include failure to consider fully topographic complexity and edge effects, underestimates of surface wetness, and the possibility of canopy sources of sulfate (foliar leaching). These results support the use of throughfall sulfate measurements as gross estimates of (1) total S deposition, (2) total dry S deposition (using net throughfall in environments where cloudwater deposition accounts for less than 5% of total sulfate deposition) and/or (3) total cloud S deposition (subtracting precipitation and dry inputs from total throughfall sulfate in high cloud environments).

Joslin, J. D.; Wolfe, M. H.

188

Impact of glacial/interglacial changes in water column geochemistry on the diagenetic cycling of barium in Black Sea sediments  

NASA Astrophysics Data System (ADS)

Changes in depositional conditions and redox environment over time affect biogeochemical processes in the seabed and in this way control the variable and selective preservation, alteration and formation of various sediment constituents and attributes - including particulate organic matter, mineral assemblages and magnetic properties. As many of these solid-phase compounds are used as paleo-environmental tracers or stratigraphic tools an assessment of diagenetic influences on the sedimentary record is crucial for accurate environmental reconstructions. We present an integrated approach of pore-water and solid-phase geochemistry as well as transport reaction modeling for sediments of the Black Sea to assess the biogeochemical history of these deposits with particular emphasis on post-depositional redistribution of barium as a consequence of changes in water column geochemistry and redox (Henkel et al., 2012). High-resolution sedimentary records of major and minor elements (Al, Ba, Ca, Sr, Ti), total organic carbon (TOC), and profiles of pore-water constituents (SO42-, CH4, Ca2+, Ba2+, Mg2+, alkalinity) were obtained for two gravity cores (core 755, 501 m water depth and core 214, 1686 m water depth) from the northwestern Black Sea. The records were examined in order to gain insight into the cycling of Ba in anoxic marine sediments characterized by a shallow sulfate-methane transition (SMT) as well as the applicability of barite as a primary productivity proxy in such a setting. The Ba records are strongly overprinted by diagenetic barite (BaSO4) remobilization and precipitation; authigenic Ba enrichments were found at both sites at and slightly above the current SMT. Transport reaction modeling was applied to simulate the migration of the SMT during the changing geochemical conditions after the Holocene seawater intrusion into the Black Sea. Based on this, sediment intervals affected by diagenetic Ba redistribution were identified. Results reveal that the intense overprint of Ba and Baxs (Ba excess above detrital average) strongly limits its correlation to primary productivity. These findings have implications for other modern and ancient anoxic basins, such as sections covering the Oceanic Anoxic Events for which Ba is frequently used as a primary productivity indicator. Our study also demonstrates the limitations concerning the use of Baxs as a tracer for downward migrations of the SMT: due to high sedimentation rates at the investigated sites, diagenetic barite fronts are buried below the SMT within a relatively short period. Thus, "relict" barite fronts would only be preserved for a few thousands of years, if at all. References Henkel, S., Mogollón, J.M., Nöthen, K., Franke, C., Bogus, K., Robin, E., Bahr, A., Blumenberg, M., Pape, T., Seifert, R., März, C., de Lange, G.J., Kasten, S. (2012) Diagenetic barium cycling in Black Sea sediments - A case study for anoxic marine environments. Geochimica et Cosmochimica Acta, 88, 88-105.

Kasten, S.; Henkel, S.; Mogollón, J. M.; Nöthen, K.; Franke, C.; Bogus, K.; Robin, E.; Bahr, A.; Blumenberg, M.; Pape, T.; Seifert, R.; Marz, C.; De Lange, G. J.

2012-12-01

189

The first barium tin(II) bromide fluoride  

NASA Astrophysics Data System (ADS)

In an effort to prepare barium tin(II) bromide fluorides for the first time, possibly similar to the chloride fluorides obtained earlier in our laboratory, precipitation reactions were carried out by mixing aqueous solutions of SnF2 and of BaBr2.2H2O. In contrast with the chloride fluoride system, a single powdered phase was obtained throughout the SnF2 - BaBr2 system, with the yield being maximum at X ? 0.25, where X is the molar fraction of barium bromide in the reaction mixture. Phase identification with the JCPDS database failed to produce a match, confirming that a new phase had been produced. The exact chemical composition of the new compound has not been obtained yet. Based on the X value for the maximum yield, the Sn/Ba ratio is likely to be 3/1 or 2/1. The Mössbauer spectrum at ambient conditions shows that bonding to tin(II) is covalent, therefore with the tin lone pair being stereoactive. The Mössbauer parameters ( ? = 3.68 mm/s, ? = 0.99 mm/s) are similar to those of SnBrF and of Sn2BrF5, thereby showing that tin is bonded to both fluorine and bromine. The larger isomer shift and lower quadrupole splitting than in tin(II) fluorides show that the stereoactivity of the tin lone pair is lower than in the fluorides. The Mössbauer parameters fit well the linear correlation of the quadrupole splitting versus the isomer shift" that has been shown to be present in other series of tin(II) compounds. The linear decrease on this correlation shows that the contribution of non-spherical orbitals ( p and d) to the lone pair is a much larger contributor to the quadrupole splitting than lattice distortions. The structure is likely made of Ba2+ cations and tin(II) fluoride bromide polyatomic anions, with covalent bonding withinthe anions.

Dénès, Georges; Merazig, Hocine; Muntasar, Abdualhafeed; Porterfield, Robyn

2014-04-01

190

Effect of Different Weight Fraction on Dielectric Properties of Barium Ferrite-Barium Titanate Composites  

NASA Astrophysics Data System (ADS)

Barium ferrite-barium titanate composite systems, (1-x)BaFe12O19 - (x)BaTiO3 with different weight fractions of × = 0.0, 0.1, 0.3 and 0.5 were prepared via the conventional solid state reaction method using nano-sized starting materials. The x-ray diffraction peaks of the composite samples show two phases which can be indexed by the hexagonal barium ferrite and tetragonal barium titanate. Field emission scanning electron microscope (FESEM) image of sample with × = 0.1 shows formation of nano-sized BaTiO3 grains spreading evenly among the micron-sized BaFe12O19 grains after sintering at 1000 °C. The dielectric properties studies at room temperature of the composites samples show that sample with BaTiO3 weight fraction of × = 0.1 has the highest dielectric constant, ?' and lowest loss tangent, tan ? in the studied frequency range between 1 Hz and 1 MHz. Its highest dielectric constant value is ~ 1.2 × 103 and its lowest loss tangent is 0.06 at 50 Hz.

Anuar, S. N.; Zalita, Z.; Shamsudin, R.

2013-04-01

191

BARIUM IN TEETH AS INDICATOR OF BODY BURDEN  

EPA Science Inventory

A study was conducted to determine the biological availability of naturally occurring barium in a municipal drinking water by the analysis of barium in deciduous teeth of children. The grade school children of two Illinois towns were chosen for the study. The towns were chosen ba...

192

A "liver" antigen associated with avian erythroblastosis: binding by bentonite and precipitation with sodium dodecyl sulphate.  

PubMed

The properties of a complement fixing antigen, EbAg, extracted from erythroblastosis-affected chicken livers are described. The antigen in extracts freed of structural protein is strongly bound by bentonite, but not by barium sulphate. Strongly alkaline solutions of sodium dodecyl sulphate are required to release the antigen from bentonite. Acidification of the detergent solution precipitates the active solution precipitates the active protein. Extraction of heme from the acidified detergent precipitate by methyl-ethyl ketone further purifies the antigen. This acid detergent treatment eliminates the need to use bentonite as a purification step. PMID:6280825

Darcel, C L

1982-01-01

193

Remediation of acid mine drainage with sulfate reducing bacteria  

SciTech Connect

Sulfate reducing bacteria have been shown to be effective at treating acid mine drainage through sulfide production and subsequent precipitation of metal sulfides. In this laboratory experiment for undergraduate environmental chemistry courses, students design and implement a set of bioreactors to remediate acid mine drainage and explain observed changes in dissolved metal concentrations and pH. Using synthetic acid mine drainage and combinations of inputs, students monitor their bioreactors for decreases in dissolved copper and iron concentrations.

Hauri, J.F.; Schaider, L.A. [Assumption College, Worcester, MA (USA)

2009-02-15

194

Proper management for morbid iatrogenic retroperitoneal barium insufflation.  

PubMed

A barium enema is a diagnostic and therapeutic procedure commonly used for colon and rectum problems. Rectal perforation with extensive intra- and/or extraperitoneal spillage of barium is a devastating complication of a barium enema that leads to a significant increase in patient mortality. Due to the low number of reported cases in recent scientific literature and the lack of experience with the management of these cases, we would like to present our treatment approach to a rare case of retroperitoneal contamination with barium, followed by its intraperitoneal involvement during a diagnostic barium enema. Our experience with long-term management of the patient and the good outcome will be depicted in this paper. PMID:25580416

Vahedian-Ardakani, Jalal; Nazerani, Shahram; Saraee, Amir; Sarmast, Ali; Saraee, Ehsan; Keramati, Mohammad Reza

2014-12-01

195

Proper Management for Morbid Iatrogenic Retroperitoneal Barium Insufflation  

PubMed Central

A barium enema is a diagnostic and therapeutic procedure commonly used for colon and rectum problems. Rectal perforation with extensive intra- and/or extraperitoneal spillage of barium is a devastating complication of a barium enema that leads to a significant increase in patient mortality. Due to the low number of reported cases in recent scientific literature and the lack of experience with the management of these cases, we would like to present our treatment approach to a rare case of retroperitoneal contamination with barium, followed by its intraperitoneal involvement during a diagnostic barium enema. Our experience with long-term management of the patient and the good outcome will be depicted in this paper. PMID:25580416

Vahedian-Ardakani, Jalal; Nazerani, Shahram; Saraee, Amir; Sarmast, Ali; Saraee, Ehsan

2014-01-01

196

Sulfate in acid rain data - do the patterns make sense?  

SciTech Connect

A high quality national record of precipitation chemistry is being collected through the operation of the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). This network began in 1978 with less than 20 sites and by the mid 1980`s had grown to about 200 sites which is about the number of sites currently in operation. Lynch et al. have been reporting time trend results for this data, with their most recent analysis showing that sulfate in NADP/NTN decreased dramatically in 1995 which agrees with the substantial decrease in sulfur dioxide emissions. The various network data available before NADP/NTN have been reported to have a variety of problems, especially related to the effect on pH of the elevated levels of base cations. The sulfate and nitrate data may be more useable. This paper reassesses the sulfate data available from the Junge network to see if these data can be used to extend the comparison of sulfate in precipitation and sulfur dioxide emissions back to the mid 1950`s.

Stensland, G.J. [Illinois State Water Survey, Champaign, IL (United States)

1997-12-31

197

Some characteristics of protein precipitation by salts.  

PubMed

The solubilities of lysozyme, alpha-chymotrypsin and bovine serum albumin (BSA) were studied in aqueous electrolyte solution as a function of ionic strength, pH, the chemical nature of salt, and initial protein concentration. Compositions were measured for both the supernatant phase and the precipitate phase at 25 degrees C. Salts studied were sodium chloride, sodium sulfate, and sodium phosphate. For lysozyme, protein concentrations in supernatant and precipitate phases are independent of the initial protein concentration; solubility can be represented by the Cohn salting-out equation. Lysozyme has a minimum solubility around pH 10, close to its isoelectric point (pH 10.5). The effectiveness of the three salts studied for precipitation were in the sequence sulfate > phosphate > chloride, consistent with the Hofmeister series. However, for alpha-chymotrypsin and BSA, initial protein concentration affects the apparent equillibrium solubility. For these proteins, experimental results show that the compositions of the precipitate phase are also affected by the initial protein concentration. We define a distribution coefficient kappa(e) to represent the equilibrium ratio of the protein concentration in the supernatant phase to that in the precipitate phase. When the salt concentration is constant, the results show that, for lysozyme, the protein concentrations in both phases are independent of the initial protein concentrations, and thus kappa(e) is a constant. For alpha-chymotrypsin and BSA, their concentrations in both phases are nearly proportional to the initial protein concentrations, and therefore, for each protein, at constant salt concentration, the distribution coefficient kappa(e) is independent of the initial protein concentration. However, for both lysozyme and alpha-chymotrypsin, the distribution coefficient falls with increasing salt concentration. These results indicate that care must be used in the definition of solubility. Solubility is appropriate when the precipitate phase is pure, but when it is not, the distribution coefficient better describes the phase behavior. PMID:18601066

Shih, Y C; Prausnitz, J M; Blanch, H W

1992-12-01

198

Barium Enhancement in NGC 6819 Blue Stragglers  

NASA Astrophysics Data System (ADS)

Possible formation pathways for blue straggler stars include mergers in hierarchical triple systems, stellar collisions during dynamical encounters, and mass transfer from a giant companion. Extensive work on the blue stragglers in the old open cluster NGC 188 (7 Gyr) has led to exciting discoveries including a binary secondary mass distribution peaked at 0.5 MSolar and the detection of three young white dwarf binary companions. These indicate that mass transfer from an asymptotic giant branch star is the dominant mechanism for blue straggler formation in open clusters. Such mass transfer events should pollute the surface abundance of the blue straggler with nucleosynthesis products from the evolved donor. The other formation pathways, mergers and collisions, are predicted to produce no such enhancements. In an effort to move beyond NGC 188 and into other open clusters we present the first results of a surface abundance study of the blue stragglers in the intermediate-aged open cluster NGC 6819 (2.5 Gyr) using the Hydra multi-object spectrograph on the WIYN 3.5 m telescope. This part of our study centers on the s-process element barium as a tracer of formation via mass transfer. We compare the blue straggler surface abundance of barium to that of a sample of main-sequence stars in NGC 6819 and find multiple blue stragglers with anomalous abundances. Surprising, most of the blue stragglers with barium anomalies show no radial-velocity evidence for a companion. We gratefully acknowledge funding from the National Science Foundation under grant AST- 0908082 and the Wisconsin Space Grant Consortium.

Milliman, Katelyn; Mathieu, Robert D.; Schuler, Simon C.

2015-01-01

199

Scattering lengths of calcium and barium isotopes  

E-print Network

We have calculated the s-wave scattering length of all the even isotopes of calcium (Ca) and barium (Ba), in order to investigate the prospect of Bose-Einstein condensation (BEC). For Ca we have used an accurate molecular potential based on detailed spectroscopic data. Our calculations show that Ca does not provide other isotopes alternative to the recently Bose condensed 40Ca that suffers strong losses because of a very large scattering length. For Ba we show by using a model potential that the even isotopes cover a broad range of scattering lengths, opening the possibility of BEC for at least one of the isotopes.

U. Dammalapati; L. Willmann; S. Knoop

2011-10-25

200

Short-cavity squeezing in barium  

NASA Technical Reports Server (NTRS)

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.

Hope, D. M.; Bachor, H-A.; Manson, P. J.; Mcclelland, D. E.

1992-01-01

201

Current-voltage characteristics of barium polymethacrylate  

SciTech Connect

In this paper current-voltage characteristics of Barium Polymethacrylate (BaPMA) in the form of Al-BaPMA-Al structures are studied. The currents are measured in the voltage range 10 V-1 kV. At low voltages an ohmic relation is observed and at higher voltages the Poole-Frenkel mechanism is proposed. The mechanism of conduction has been explained on the basis of different current-voltage and current-temperature curves. The activation energy values calculated using Arrhenius relation fall in the range 0.25-2 eV, suggesting a sequence of trapping levels.

Chohan, M.H. (Lab. for Electrical Characterization of Polymers, Dept. of Electronics, Quaid-i-Azam Univ., Islamabad (PK)); Zulfiqar, M.; Sapra, Z.H.; Husain, R.; Zulfiqar, S. (Dept. of Chemistry, Quaid-i-Azam Univ., Islamabad (PK))

1992-06-30

202

Scattering lengths of calcium and barium isotopes  

SciTech Connect

We have calculated the s-wave scattering length of all the even isotopes of calcium (Ca) and barium (Ba) in order to investigate the prospect of Bose-Einstein condensation (BEC). For Ca we have used an accurate molecular potential based on detailed spectroscopic data. Our calculations show that Ca does not provide other isotopes alternative to the recently Bose condensed {sup 40}Ca that suffers strong losses because of a very large scattering length. For Ba we show by using a model potential that the even isotopes cover a broad range of scattering lengths, opening the possibility of BEC for at least one of the isotopes.

Dammalapati, U.; Willmann, L.; Knoop, S. [Kernfysisch Versneller Instituut (KVI), University of Groningen, Zernikelaan 25, 9747 AA Groningen (Netherlands); LaserLaB Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands)

2011-11-15

203

Plagioclase Dissolution during CO2-SO2 Cosequestration: Effects of Sulfate.  

PubMed

Geologic CO2 sequestration (GCS) is one of the most promising methods to mitigate the adverse impacts of global climate change. The performance of GCS can be affected by mineral dissolution and precipitation induced by injected CO2. Cosequestration with acidic gas such as SO2 can reduce the high cost of GCS, but it will increase the sulfate's concentration in GCS sites, where sulfate can potentially affect plagioclase dissolution/precipitation. This work investigated the effects of 0.05 M sulfate on plagioclase (anorthite) dissolution and subsequent mineral precipitation at 90 °C, 100 atm CO2, and 1 M NaCl, conditions relevant to GCS sites. The adsorption of sulfate on anorthite, a Ca-rich plagioclase, was examined using attenuated total reflectance Fourier-transform infrared spectroscopy and then simulated using density functional theory calculations. We found that the dissolution rate of anorthite was enhanced by a factor of 1.36 by the formation of inner-sphere monodentate complexes between sulfate and the aluminum sites on anorthite surfaces. However, this effect was almost completely suppressed in the presence of 0.01 M oxalate, an organic ligand that can exist in GCS sites. Interestingly, sulfate also inhibited the formation of secondary mineral precipitation through the formation of aluminum-sulfate complexes in the aqueous phase. This work, for the first time, reports the surface complexation between sulfate and plagioclase that can occur in GCS sites. The results provide new insights for obtaining scientific guidelines for the proper amount of SO2 coinjection and finally for evaluating the economic efficiency and environmental safety of GCS operations. PMID:25549263

Min, Yujia; Kubicki, James D; Jun, Young-Shin

2015-02-01

204

Natural or anthropogenic? On the origin of atmospheric sulfate deposition in the Andes of southeastern Ecuador  

NASA Astrophysics Data System (ADS)

Atmospheric sulfur deposition above certain limits can represent a threat to tropical forests, causing nutrient imbalances and mobilizing toxic elements that impact biodiversity and forest productivity. Atmospheric sources of sulfur deposited by precipitation have been roughly identified in only a few lowland tropical forests. Even scarcer are studies of this type in tropical mountain forests, many of them mega-diversity hotspots and especially vulnerable to acidic deposition. In these places, the topographic complexity and related streamflow conditions affect the origin, type, and intensity of deposition. Furthermore, in regions with a variety of natural and anthropogenic sulfur sources, like active volcanoes and biomass burning, no source emission data has been used for determining the contribution of each source to the deposition. The main goal of the current study is to evaluate sulfate (SO4- deposition by rain and occult precipitation at two topographic locations in a tropical mountain forest of southern Ecuador, and to trace back the deposition to possible emission sources applying back-trajectory modeling. To link upwind natural (volcanic) and anthropogenic (urban/industrial and biomass-burning) sulfur emissions and observed sulfate deposition, we employed state-of-the-art inventory and satellite data, including volcanic passive degassing as well. We conclude that biomass-burning sources generally dominate sulfate deposition at the evaluated sites. Minor sulfate transport occurs during the shifting of the predominant winds to the north and west. Occult precipitation sulfate deposition and likely rain sulfate deposition are mainly linked to biomass-burning emissions from the Amazon lowlands. Volcanic and anthropogenic emissions from the north and west contribute to occult precipitation sulfate deposition at the mountain crest Cerro del Consuelo meteorological station and to rain-deposited sulfate at the upriver mountain pass El Tiro meteorological station.

Makowski Giannoni, S.; Rollenbeck, R.; Trachte, K.; Bendix, J.

2014-10-01

205

Natural or anthropogenic? On the origin of atmospheric sulfate deposition in the Andes of southeastern Ecuador  

NASA Astrophysics Data System (ADS)

Atmospheric sulfur deposition above certain limits can represent a threat to tropical forests, causing nutrient imbalances and mobilizing toxic elements that impact biodiversity and forest productivity. Atmospheric sources of sulfur deposited by precipitation have being roughly identified in only a few lowland tropical forests. Even scarcer are these type of studies in tropical mountain forests, many of them megadiversity hotspots and especially vulnerable to acidic deposition. Here, the topographic complexity and related streamflow condition the origin, type, and intensity of deposition. Furthermore, in regions with a variety of natural and anthropogenic sulfur sources, like active volcanoes and biomass-burning, no source-emission data has been used for determining the contribution of each of them to the deposition. The main goal of the current study is to evaluate sulfate (SO4-) deposition by rain and occult precipitation at two topographic locations in a tropical mountain forest of southern Ecuador, and to trace back the deposition to possible emission sources applying back trajectory modeling. To link upwind natural (volcanic) and anthropogenic (urban/industrial and biomass-burning) sulfur emissions and observed sulfate deposition, we employed state of the art inventory and satellite data, including volcanic passive degassing as well. We conclude that biomass-burning sources generally dominate sulfate deposition at the evaluated sites. Minor sulfate transport occurs during the shifting of the predominant winds to the north and west. Occult precipitation sulfate deposition and likely rain sulfate deposition are mainly linked to biomass-burning emissions from the Amazon lowlands. Volcanic and anthropogenic emissions from the north and west contribute to occult precipitation sulfate deposition at the mountain crest Cerro del Consuelo meteorological station and to rain-deposited sulfate at the upriver mountain-pass El Tiro meteorological station.

Makowski Giannoni, S.; Rollenbeck, R.; Trachte, K.; Bendix, J.

2014-05-01

206

308 Brain Research, 498 (1989) 308-314 Potassium conductance block by barium in amphibian  

E-print Network

308 Brain Research, 498 (1989) 308-314 Elsevier BRES 14831 Potassium conductance block by barium cell; Glial cell; Retina; Barium; Potassium conductance; Tiger salamander The effect of barium on M in situ (retinal slice and isolated retina). Barium effects were similar in both cases. In dissociated

Newman, Eric A.

207

Fluid seepage along the San Clemente Fault scarp: basin-wide impact on barium cycling  

E-print Network

Fluid seepage along the San Clemente Fault scarp: basin-wide impact on barium cycling Marta E present evidence that the barium released at cold seeps along the San Clemente Fault zone may significantly impact the geochemical budget of barium within the basin. Barium fluxes at seep localities

Huh, Chih-An

208

Cation non-stoichiometry in yttrium-doped barium zirconate: phase behavior, microstructure, and proton conductivity  

E-print Network

Cation non-stoichiometry in yttrium-doped barium zirconate: phase behavior, microstructure approach in which the barium deficiency is precisely controlled. The perovskite phase is tolerant to barium-phase region barium deficiency also has a detrimental impact on grain boundary conductivity, as a result both

209

Earthquake-induced barium anomalies in the Lisan Formation, Dead Sea Rift valley, Israel  

E-print Network

Earthquake-induced barium anomalies in the Lisan Formation, Dead Sea Rift valley, Israel Amitai Editor: L. Stixrude Keywords: barium Dead Sea seismite earthquake Lisan recurrence rate Prominent barium The present paper is a rst report of prominent barium concen- tration anomalies in seismically perturbed

Marco, Shmuel "Shmulik"

210

Relation of precipitation quality to storm type, and deposition of dissolved chemical constituents from precipitation in Massachusetts, 1983-85  

USGS Publications Warehouse

Precipitation samples were collected for 83 storms at a rural inland site in Princeton, Mass., and 73 storms at a rural coastal site in Truro, Mass., to examine the quality of precipitation from storms and relate quality to three storm types (oceanic cyclone, continental cyclone, and cold front). At the inland site, Princeton, ranked-means of precipitation depth, storm duration, specific conductance, and concentrations and loads of hydrogen, sulfate, aluminum, bromide, and copper ions were affected by storm type. At the coastal site, Truro, ranked means of precipitation depth, storm duration, and concentrations and loads of calcium, chloride, magnesium, potassium, and sodium ions were affected by storm type. Precipitation chemistry at the coastal site was 85 percent oceanic in orgin, whereas precipitation 72 kilometers inland was 60 percent hydrogen, nitrate, and sulfate ions, reflecting fossil-fuel combustion. Concentrations and loads for specific conductance and 9 chemical constituents on an annual and seasonal basis were determined from National Atmospheric Deposition Program data for spring 1983 through winter 1985 at Quabbin (rural, inland), Waltham (suburban, inland) and Truro (rural, coastal), Massachusetts. Concentrations of magnesium, potassium, sodium, and chloride concentrations were highest at the coast and much lower inland, with very little difference between Waltham and Quabbin. Loads of ammonium, nitrate, sulfate, and hydrogen are highest at Quabbin and are about equal at Waltham and Truro. About twice as much nitrate and hydrogen and about 35 percent more sulfate is deposited at Quabbin than at Waltham or Truro; this pattern indicates that the interior of Massachusetts receives more acidic precipitation than do the eastern or the coastal areas of Massachusetts.

Gay, F.B.; Melching, C.S.

1995-01-01

211

Application of Biostimulation for Remediation of Sulfate-Contaminated Groundwater at a Mining Site  

NASA Astrophysics Data System (ADS)

There is growing concern regarding sulfate contamination of groundwater. One innovative in-situ remediation option under investigation is biostimulation through addition of electron-donor amendments to enhance sulfate reduction. Two pilot-scale ethanol-injection tests were conducted at a former uranium mining site that is contaminated with sulfate and nitrate (with a lack of heavy metals), and for which there appears to be minimal natural attenuation of sulfate. The first test was a push-pull test that had a limited zone of influence, while the second test was a single-well injection test in which additional downgradient wells were monitored. For both tests, sulfate concentrations began to decline within a few weeks of injection, after nitrate concentrations were significantly reduced. Concomitantly, aqueous concentrations of manganese, iron, and hydrogen sulfide increased from background. Monitoring over many months revealed that the declines in sulfate concentration conformed to exponential decay, with first-order decay rates of approximately 0.01 /d. Analysis of sulfur stable isotope data indicated that the decrease in sulfate concentrations was microbially mediated. The results also indicated that sulfides formed during sulfate reduction may have undergone partial re-oxidation. This study illustrates the feasibility of using ethanol injection for remediation of sulfate-contaminated groundwater. However, re-oxidation of sulfides (both metal sulfide precipitates and hydrogen sulfide gas) is a potential issue of significance that would need to be addressed.

Miao, Z.; Carroll, K. C.; Carreon, C.; Brusseau, M. L.

2011-12-01

212

Barium ion Zeeman and space potential diagnostic  

NASA Astrophysics Data System (ADS)

A diagnostic has been developed to simultaneously determine the magnetic field and space potential in fusion-like plasmas.1 In Fig. 1, we show schematically the diagnostic concept. The magnetic field is determined by a measurement of the Zeeman resonance absorption pattern of an energetic (<30 keV) barium ion beam (10 ?A). The spectrum is obtained by laser-induced fluorescence. In our approach, similar to a technique developed at UC Irvine,2 the absorption spectrum of the barium ion beam is measured as the frequency of a narrow-linewidth dye laser is scanned over the Doppler-shifted Zeeman-split resonance transition. The resonantly scattered light at 4934.1 Å is collected without frequency processing other than a narrow-band filter to reduce background plasma light. Space potentials are determined by a measurement of the Doppler shift due to a change in beam energy, E=E0-e?p(E0 is the beam energy, ?p is the plasma potential). The laser is injected tangentially to the ion beam to take advantage of the narrow Doppler spread in the direction of the beam.

Wickham, M.; Lazar, N. H.; Rynn, N.

1985-05-01

213

Characterization of Jarosite Formed upon Bacterial Oxidation of Ferrous Sulfate in a Packed-Bed Reactor †  

PubMed Central

A packed-bed bioreactor with activated-carbon particles as a carrier matrix material inoculated with Thiobacillus ferrooxidans was operated at a pH of 1.35 to 1.5 to convert ferrous sulfate to ferric sulfate. Despite the low operating pH, trace amounts of precipitates were produced in both the reactor and the oxidized effluent. X-ray diffraction and chemical analyses indicated that the precipitates were well-ordered potassium jarosite. The chemical analyses also revealed a relative deficiency of Fe and an excess of S in the reactor sample compared with the theoretical composition of potassium jarosite. Images PMID:16347799

Grishin, Sergei I.; Bigham, Jerry M.; Tuovinen, Olli H.

1988-01-01

214

Do all barium stars have a white dwarf companion?  

NASA Technical Reports Server (NTRS)

International Ultraviolet Explorer short-wavelength, low-dispersion spectra were analyzed for four barium, two mild barium, and one R-type carbon star in order to test the hypothesis that the barium and related giants are produced by mass transfer from a companion now present as a white dwarf. An earlier tentative identification of a white dwarf companion to the mild barium star Zeta Cyg is confirmed. For the other stars, no ultraviolet excess attributable to a white dwarf is seen. Limits are set on the bolometric magnitude and age of a possible white dwarf companion. Since the barium stars do not have obvious progenitors among main-sequence and subgiant stars, mass transfer must be presumed to occur when the mass-gaining star is already on the giant branch. This restriction, and the white dwarf's minimum age, which is greater than 8 x 10 to the 8th yr, determined for several stars, effectively eliminates the hypothesis that mass transfer from an asymptotic giant branch star creates a barium star. Speculations are presented on alternative methods of producing a barium star in a binary system.

Dominy, J. F.; Lambert, D. L.

1983-01-01

215

Characterization, antioxidant and cytotoxic activity of sulfated derivatives of a water-insoluble polysaccharides from Dictyophora indusiata.  

PubMed

The present study described the characterization and biological properties of water?soluble sulfated polysaccharides prepared from water?insoluble polysaccharide (DIP), which were extracted from Dictyophora indusiata. The sulfation of DIP was performed using the chlorosulfonic acid?pyridine method. The water solubilities of the sulfated derivatives were measured at room temperature according to the Chinese Pharmacopoeia. The scavenging activity of hydroxyl radicals and 1,1?diphenyl?2?picrylhydrazyl (DPPH) as determined, together with the reduction ability of the sulfated polysaccharides. The cytotoxic and antiproliferative effects of DIP and the sulfated derivatives on MCF?7 and B16 cells were then determined using an MTT assay. The substitution degrees of the sulfated polysaccharides were 0.584 (S1?DIP), 0.989 (S2?DIP) and 1.549 (S3?DIP) according to barium chloride?gelatin nephelometry. Infrared spectroscopy and 13C?nuclear magnetic resonance indicated that the substitution of S?DIP occurred mainly at the C?6 position, followed by the C?4 and C?2 positions. A significant increase was noted in the antioxidant activity of the sulfated derivatives compared with that of DIP. In addition, the S?DIPs exhibited a more marked reducing capacity and clearing activity of hydroxyl radicals and DPPH. This indicated that the antioxidant capacity of the polysaccharides was significantly higher following sulfation. Furthermore, in in vitro cell investigations, DIP exhibited no inhibitory effects on the growth of the B16 or MCF?7 tumor cells. However, the sulfated derivatives exerted marked inhibitory effects on these cell lines. Sulfate modification may therefore contribute to an improvement in water solubility and in the antioxidant and antitumor activities of natural DIP. PMID:25484243

Deng, Chao; Xu, Jingjing; Fu, Haitian; Chen, Jinghua; Xu, Xin

2015-04-01

216

A high-altitude barium radial injection experiment  

NASA Technical Reports Server (NTRS)

A rocket launched from Poker Flat, Alaska, carried a new type of high-explosive barium shaped charge to 571 km, where detonation injected a thin disk of barium vapor with high velocity nearly perpendicular to the magnetic field. The TV images of the injection are spectacular, revealing three major regimes of expanding plasma which showed early instabilities in the neutral gas. The most unusual effect of the injection is a peculiar rayed barium-ion structure lying in the injection plane and centered on a 5 km 'black hole' surrounding the injection point. Preliminary electrostatic computer simulations show a similar rayed development.

Wescott, E. M.; Stenbaek-Nielsen, H. C.; Hallinan, T. J.; Deehr, C. S.; Romick, G. J.; Olson, J. V.; Roederer, J. G.; Sydora, R.

1980-01-01

217

Determination of trace elements in triglycine sulfate solutions  

NASA Technical Reports Server (NTRS)

Ten elements were divided into 2 groups. The elements in the first group included iron, nickel, chromium, manganese, copper, and gold. The elements in the second group included zinc, cobalt, lead, cadmium, and gold. Five ppm of each element in each group was spiked in a 1 percent triglycine sulfate (TGS) solution. Glycine was removed with 1-naphthyl isocyanate in ether medium. The glycine derivative 1-naphthyl isocyanate glycine was removed by filtration, and the filtrates were analyzed for the different elements. Analysis of these elements was performed by using the 5100 Perkin-Elmer Atomic Absorption Spectrophotometer. The result of these experiments was the observation that there was a decrease in the concentration of chromium and gold, which was interpreted to be due to the chelation of these elements by the derivative 1-naphthyl isocyanate glycine. Further research is needed to determine the concentration of other elements in triglycine sulfate (TGS) solutions. These elements will include lithium, sodium, rubidium, magnesium, calcium, strontium, barium, aluminum, and silicon. These are the most likely elements to be found in the sulfuric acid used in manufacturing the TGS crystal. Moreover, we will extend our research to investigate the structural formula of the violet colored chelated compounds, which had been formed by interaction of the derivative 1-naphthyl isocyanate glycine with the different elements, such as gold, chromium.

Tadros, Shawky H.

1993-01-01

218

Ion Exchange Studies for Removal of Sulfate from Hanford Tank Waste Envelope C (241-AN-107) Using SuperLig 655 Resin  

SciTech Connect

BNFL Inc. is evaluating various pretreatment technologies to mitigate the impacts of sulfate on the LAW vitrification system. One pretreatment technology for separating sulfate from LAW solutions involves the use of SuperLig{reg_sign} 655 (SL-655), a proprietary ion exchange material developed and supplied by IBC Advanced Technologies, Inc., American Fork, UT. This report describes testing of SL-655 with diluted ([Na] {approximately} 5 M) waste from Hanford Tank 241-AN-107 at Battelle, Pacific Northwest Division. Batch contact studies were conducted from 4 to 96 hours to determine the sulfate distribution coefficient and reaction kinetics. A small-scale ion exchange column test was conducted to evaluate sulfate removal, loading, breakthrough, and elution from the SL-655. In all of these tests, an archived 241-AN-107 tank waste sample (pretreated to remove Cs, Sr, and transuranics elements) was used. The experimental details and results are described in this report. Under the test conditions, SL-655 was found to have no significant ion exchange affinity for sulfate in this matrix. The batch contact study resulted in no measurable difference in the aqueous sulfate concentration following resin contact (K{sub d} {approximately} 0). The column test also demonstrated SL-655 had no practical affinity for sulfate in the tested matrix. Within experimental error, the sulfate concentration in the column effluent was equal to the concentration in the feed after passing 3 bed volumes of sample through the columns. Furthermore, some, if not all, of the decreased sulfate concentration in these first three column volumes of effluent can be ascribed to mixing and dilution of the 241-AN-107 feed with the interstitial liquid present in the column at the start of the loading cycle. Finally, ICP-AES measurements on the eluate solutions showed the presence of barium as soon as contact with the feed solution is completed. Barium is a metal not detected in the feed solution. Should the loss of barium be correlated with the resin's ability to selectively complex sulfate, then maintaining even the current limited resin characteristics for sulfate complexation over multiple cycles becomes questionable.

DE Kurath; JR Bontha; DL Blanchard; SK Fiskum; BM Rapko

2000-08-23

219

Designed microstructures in textured barium hexaferrite  

NASA Astrophysics Data System (ADS)

It is a fundamental principle of materials science that the microstructure of a material defines its properties and ultimately its performance for a given application. A prime example of this can be found in the large conch shell Strombus gigas, which has an intricate microstructure extending across five distinct length scales. This microstructure gives extraordinary damage tolerance to the shell. The structure of Strombus gigas cannot be replicated in a modern engineering ceramic with any existing processing technique, so new processing techniques must be developed to apply this structure to a model material. Barium hexaferrite was chosen as a model material to create microstructures reminiscent of Strombus gigas and evaluate its structure-property relations. This work describes novel processing methods to produce textured barium hexaferrite with no coupling between the sample geometry and the texture direction. This technique, combining magnetic field-assisted gelcasting with templated grain growth, also allows multilayer samples to be fabricated with different texture directions in adjacent layers. The effects of adding either B2O3 or excess BaCO 3 on the densification and grain growth of barium hexaferrite was studied. The texture produced using this technique was assessed using orientation imaging microscopy (OIM) at Oak Ridge National Laboratory. These measurements showed peak textures as high as 60 MRD and sharp interfaces between layers cast with different texture directions. The effect of oxygen on the quality of gelcasting is also discussed, and it is shown that with proper mold design, it is possible to gelcast multiple layers with differing texture directions without delamination. Monolithic and multilayer samples were produced and tested in four point bending to measure the strength and work of fracture. Modulus measurements, made with the ultrasonic pulse-echo technique, show clear signs of microcracking in both the isotropic and textured samples. Both the strength and work of fracture were shown to be affected by the texture direction. The multilayer samples did not show significant improvements in either strength or work of fracture, but they did show much less variability than the monolithic samples.

Hovis, David Brian

220

Broad band absorbance of barium hexaferrite thick films in the 8-12 GHz frequency spectrum  

NASA Astrophysics Data System (ADS)

Screen printed barium hexaferrite thick films on alumina with broad band absorbance in the X band were fabricated. BaFe12O19 was synthesized using a cost effective low temperature co-precipitation method with varying Fe/Ba molar ratio and pH. The thick film showed increased grain size for higher Fe/Ba molar ratio. The complex permittivity and permeability of these thick films showed wavelike behavior in a range of 9.5 GHz to 10.5 GHz. Synthesis conditions of hexaferrite powder and the dependency of the complex permittivity and the permeability of BaFe12O19 thick films on thickness in the 8 to 12 and the permeability of BaFe12O19 thick films in the 8 GHz to 12 GHz frequency spectrum are discussed in this paper. The high frequency (8 GHz to 12 GHz) reflection loss of thick film barium hexaferrite was investigated and was found to be dependent on the synthesis parameters and the thickness of the thick films. The absorption measured was more than 80% over the entire X band.

Kulkarni, D. C.; Puri, Vijaya

2011-03-01

221

Nanoparticles Flat Precipitates  

E-print Network

20 nm Nanorods Nanoparticles Flat Precipitates 10 nm To improve the performance of superconducting precipitates (red arrows). Artificial and Self-assembled Vortex-pinning Centers in Superconducting Ba(Fe1-x

Weston, Ken

222

Phased surgical treatment of barium enema-induced rectal injury and retention of barium in the pelvic floor space  

PubMed Central

Iatrogenic injuries caused by barium enema are rarely reported. Following a phased surgical protocol for up to one year, we have successfully treated a patient with rectal injury and severe infection of the pelvic floor space complicated with retention of large amounts of barium and vaginal fistula. In this article, the phased surgery planning for the treatment of rectal injury complicated with vaginal fistula is discussed in terms of the pros and cons, and the observed effect and evolution of barium retained in the pelvic floor space are described. PMID:25405155

Yang, Xuefei; Xia, Ligang; Huang, Jun; Wang, Jianping

2014-01-01

223

A precipitation occurrence model  

Microsoft Academic Search

.  ?An imbedded renewal process as a model of precipitation occurrence is fairly well known. Data permitting verification of\\u000a assumptions determining such a model, for example independence and distribution of sojourn times, are available rather rarely,\\u000a however, due to problems with definition of a precipitation. An operational definition of a precipitation is obtained by associating\\u000a the precipitation occurrence with an opening

J. Mohapl

2002-01-01

224

Theoretical isotope shifts in neutral barium  

E-print Network

The present work deals with a set of problems in isotope shifts of neutral barium spectral lines. Some well known transitions ($6s^2~^1S_0-6s6p~^{1,3}P^o_1$ and $6s^2~^1S_0-6p^2~^3P_0$) are first investigated. Values of the changes in the nuclear mean-square charge radius are deduced from the available experimental isotope shifts using our ab initio electronic factors. The three sets $\\{ \\delta\\langle r^2\\rangle^{A,A'}\\} $ obtained from these lines are consistent with each other. The combination of the available nuclear mean-square radii with our electronic factors for the $6s5d~^3D_{1,2} -6s6p~^{1}P^o_1$ transitions produces isotope shift values in conflict with the laser spectroscopy measurements of Dammalapati et al. (Eur. Phys. J. D 53, 1 (2009)).

Nazé, Cédric; Godefroid, Michel

2015-01-01

225

Synthesis and characterization of barium hexagonal ferrite  

NASA Astrophysics Data System (ADS)

Barium Hexagonal ferrite (BaFe12O19) was synthesized by a two step process, first by high-energy ball milling and then sintering the milled powder subsequently at 950°C. The phase formation and morphology studies were carried out using X-ray Diffraction (XRD) and High Resolution Scanning Electron Microscopy (HRSEM) respectively. XRD results clearly show the phase purity and the good crystalline nature of BaFe12O19. The mean particle size was found to be 80 nm from the SEM image. The magnetic properties such as saturation magnetization and coercive field were calculated from the magnetization curve, which was obtained using Vibrating Sample Magnetometer (VSM). A possible relation between the magnetic hysteresis curve and the microstructure of the sintered sample has been investigated.

Manikandan, M.; Venkateswaran, C.

2013-02-01

226

Magnetic properties of substituted barium ferrite powders  

SciTech Connect

Hexagonal barium ferrites were prepared using the citrate method. Cobalt and titanium were added in the amounts x from 0.2 to 1.1 ion/f.u. related to the formula BaCo{sub x}Ti{sub x}Fe{sub 12{minus}2x}O{sub 19}. The heat treatment has been applied in three steps of 550 C/5 hrs, 850 C/2 hrs and 1,100 C/2 hrs. The following magnetic properties have been achieved: H{sub c} {approximately} 80 kA/m, J{sub s} {approximately} 120 {times} 10{sup {minus}6} Tkg{sup {minus}1} m{sup 3}, and J{sub r} {approximately} 60 {times} 10{sup {minus}6} Tkg{sup {minus}1} m{sup 3} in the composition for which x is equal to 0.5 ion/f.u. The magnetic parameters have been measured by the vibration magnetometer.

Gruskova, A. [Slovak Univ. of Technology, Bratislava (Slovakia). Dept. of Electrotechnology] [Slovak Univ. of Technology, Bratislava (Slovakia). Dept. of Electrotechnology

1994-03-01

227

A new polymorph of barium chloroanilate trihydrate.  

PubMed

Single crystals of a new polymorph of the title compound, barium(II) 3,6-dichloro-2,5-dihydroxy-1,4-benzoquinone trihydrate, Ba2+.C6Cl2O4(2-).3H2O, have been grown in sodium metasilicate gel. Each Ba2+ cation is coordinated by eight O atoms. The Ba2+ cations are bridged by an O atom of a ligand around the centre of symmetry at Wyckoff position 4a and by the O atom of a water molecule around the centre of symmetry at Wyckoff position 4b, forming a sheet parallel to the (100) plane. Loose contacts are found around one of the water molecules, as observed in the Cmca form. PMID:11173382

Kashino, S; Ishida, H; Fukunaga, T; Oishi, S

2001-01-01

228

Calculated emission rates for barium releases in space  

NASA Technical Reports Server (NTRS)

The optical emissions from barium releases in space are caused by resonance and fluorescent scattering of sunlight. Emission rates for the dominant ion and neutral lines are calculated assuming the release to be optically thin and the barium to be in radiative equilibrium with the solar radiation. The solar spectrum has deep Fraunhofer absorption lines at the primary barium ion resonances. A velocity component toward or away from the sun will Doppler shift the emission lines relative to the absorption lines and the emission rates will increase many-fold over the rest value. The Doppler brightening is important in shaped charge or satellite releases where the barium is injected at high velocities. Emission rates as a function of velocity are calculated for the 4554, 4934, 5854, 6142 and 6497 A ion emission lines and the dominant neutral line at 5535 A. Results are presented for injection parallel to the ambient magnetic field, B, and for injection at an angle to B.

Stenbaek-Nielsen, H. C.

1989-01-01

229

Preparation, characterization, biological activity, and transport study of polystyrene based calcium-barium phosphate composite membrane.  

PubMed

Calcium-barium phosphate (CBP) composite membrane with 25% polystyrene was prepared by co-precipitation method. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformed infrared (FTIR), and Thermogravimetric analysis (TGA) were used to characterize the membrane. The membrane was found to be crystalline in nature with consistent arrangement of particles and no indication of visible cracks. The electrical potentials measured across the composite membrane in contact with univalent electrolytes (KCl, NaCl and LiCl), have been found to increase with decrease in concentrations. Thus the membrane was found to be cation-selective. Transport properties of developed membranes may be utilized for the efficient desalination of saline water and more importantly demineralization process. The antibacterial study of this composite membrane shows good results for killing the disease causing bacteria along with waste water treatment. PMID:23910337

Khan, Mohammad Mujahid Ali; Rafiuddin

2013-10-01

230

Effective removal of methyl blue by fine-structured strontium and barium phosphate nanorods  

NASA Astrophysics Data System (ADS)

In this work, the composite of strontium phosphate and barium phosphate (called SBP) nanorods have been synthesized, characterized and studied for removal of methyl blue (MB). The effects of pH, temperature, contact time, initial dye concentration on removal of MB were studied in detail. Results suggest that pH and temperature were not critical limiting factors for the removal of MB. Reaching equilibrium was very rapid (within 10 min) and the high adsorption capacity of MB by SBP nanorods was 1691.8 mg/g at initial dye concentration of 2000 mg/L. The adsorption process obeyed the pseudo-second-order kinetics model and Langmuir isotherm model. Importantly, the mechanism contributed to the MB removal was proposed to be the ionic interaction and hydrogen bonds for low dye concentration, chemical precipitation for high dye concentration. It is predicted that the SBP nanorods being an effective adsorbent for elimination of MB from colored aqueous solutions.

Zhang, Fan; Song, Weijie; Lan, Jing

2015-01-01

231

Synthesis, photoluminescence and magnetic properties of barium vanadate nanoflowers  

SciTech Connect

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: {yields} 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. {yields} The photoluminescence and magnetic properties of the barium vanadate nanoflowers were investigated at room temperature. The strong bluish-green emission was observed. {yields} The ferromagnetic behavior of the barium vanadate nanoflowers was found with saturation magnetization of about 83.50 x 10{sup -3} emu/g, coercivity of 18.89 Oe and remnant magnetization of 4.63 x 10{sup -3} emu/g. {yields} 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{sub 2}O{sub 5} and BaCl{sub 2} at 200 {sup o}C for 13 h. XRD and XPS spectrum of the as-synthesized sample indicate it is hexagonal Ba{sub 3}V{sub 2}O{sub 8} with small amount of Ba{sub 3}VO{sub 4.8} coexistence. Scan electron microscope and transmission electron microscope display that the flower-shaped crystals are composed of nanosheets with thickness of {approx}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{sub 4} tetrahedron with T{sub d} symmetry in Ba{sub 3}V{sub 2}O{sub 8}. The ferromagnetic behavior of the barium vanadate nanoflowers has been found with saturation magnetization of about 83.50 x 10{sup -3} emu/g, coercivity of 18.89 Oe and remnant magnetization of 4.63 x 10{sup -3} emu/g, which is mainly due to the presence of a non-orthovanadate phase with spin S = 1/2.

Xu, Jing [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China) [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China); Chongqing University of Science and Technology, Chongqing 401331 (China); Hu, Chenguo, E-mail: hucg@cqu.edu.cn [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China)] [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China); Xi, Yi [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China)] [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China); Peng, Chen [School of Physical Science and Technology, Southwest University, Chongqing 400715 (China)] [School of Physical Science and Technology, Southwest University, Chongqing 400715 (China); Wan, Buyong; He, Xiaoshan [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China)] [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China)

2011-06-15

232

A search for technetium (Tc II) in barium stars  

NASA Technical Reports Server (NTRS)

The authors searched without success for the lines of Tc II at 2647.02, 2610.00 and 2543.24 A in IUE spectra of the barium stars HR 5058, Omicron Vir, and Zeta Cap. The lack of Tc II implies that the observed s-process enhancements were produced more than half a million years ago and supports the suggestion that the spectral peculiarities of barium stars are probably related to the binary nature of the stars.

Little-Marenin, Irene R.; Little, Stephen J.

1987-01-01

233

'Skidding' of the CRRES G-9 barium release  

NASA Technical Reports Server (NTRS)

A simulation study and experimental data of the CRRES G-9 ionospheric barium release are presented. The simulation study is based on a 2D electrostatic code that incorporates time-dependent coupling to the background plasma. It is shown that the densest portion of the barium ion cloud 'skids' about 15 km within the first three seconds following the release, consistent with the optical data analyses.

Huba, J. D.; Mitchell, H. G.; Fedder, J. A.; Bernhardt, P. A.

1992-01-01

234

Barium ferrite nanoparticles prepared directly by aerosol pyrolysis  

Microsoft Academic Search

BaFe12O19 nanoparticles, 10 nm in diameter, have been obtained by combination of two methods, the citrate precursor and the aerosol pyrolysis technique. For the first time, well-crystallised barium ferrite particles were obtained by pyrolysis of an aerosol, produced by ultrasonic frequency spraying of a barium iron citrate aqueous solution, in a tubular furnace at 1000°C, without further heat treatment. The

T González-Carreño; M. P Morales; C. J Serna

2000-01-01

235

Growth and characterization of barium ferrite films grown using PECVD  

Microsoft Academic Search

Deposition of c-axis perpendicularly oriented barium ferrite (BaFe12O19) films was attempted by means of plasma enhanced chemical vapor deposition (PECVD). A substituted acetylacetonate barium complex has been used with ferrocene in a PECVD system to deposit films of BaFe12O19. These films were examined for crystallinity, composition and magnetic properties. The crystallinity was measured by x-ray diffraction (XRD), the composition was

Radhakrishnan Padmanabhan; Ehab Marji; Yanko Kranov; Daqing Zhang; David N. McIlroy

2004-01-01

236

Barium recovery by crystallization in a fluidized-bed reactor: effects of pH, Ba/P molar ratio and seed.  

PubMed

The effects of process conditions, including upward velocity inside the column, the amount of added seed and seed size, the pH value of the precipitant or the phosphate stream and the Ba/P molar ratio in a fluidized-bed reactor (FBR) were studied with a view to producing BaHPO? crystals of significant size and maximize the removal of barium. XRD were used to identify the products that were collected from the FBR. Experimental results show that an upward velocity of 48 cmmin(-1) produced the largest BaHPO? crystals with a size of around 0.84-1.0mm. The addition of seed crystals has no effect on barium removal. The use of a seed of a size in the ranges unseeded<0.149-0.29 mm<0.149 mm<0.29-0.42 mm produced increasing amounts of increasingly large crystals. The largest BaHPO? crystals were obtained at pH 8.4-8.8 with a Ba/P molar ratio of 1.0. In the homogeneous and heterogeneous processes, around 98% of barium was removed at pH 8.4-8.6 and [Ba]/[P]=1.0. The XRD results show that a significant amount of barium phosphate (Ba?(PO?)?) was obtained at pH 11. The compounds BaHPO? and BaO were present at a pH of below 10. PMID:24462085

Su, Chia-Chi; Reano, Resmond L; Dalida, Maria Lourdes P; Lu, Ming-Chun

2014-06-01

237

Intestinal and Renal Effects of Low-Volume Phosphate and Sulfate Cathartic Solutions Designed for Cleansing the Colon: Pathophysiological Studies in Five Normal Subjects  

Microsoft Academic Search

OBJECTIVES:Ingestion of a concentrated low-volume phosphate solution produces copious diarrhea, which cleanses the colon, but it occasionally causes renal failure due to calcium phosphate precipitation in renal tubules. We hypothesized that a concentrated low-volume sulfate solution would be an equally effective cathartic, and that urine produced after sulfate would have less tendency to precipitate calcium salts than urine produced after

Viralkumar Patel; Michael Nicar; Michael Emmett; John Asplin; John A Maguire; Carol A Santa Ana; John S Fordtran

2009-01-01

238

Bacterially Induced Dolomite Formation in the Presence of Sulfate Ions under Aerobic Conditions  

NASA Astrophysics Data System (ADS)

The origin of dolomite remains a long-standing enigma in sedimentary geology because, although thermodynamically favorable, precipitation of dolomite from modern seawater does not occur. Experiments conducted at elevated temperatures (200 oC) indicated that the presence of small concentrations of sulfate ions inhibits the transformation of calcite to dolomite [1]. Indeed, sulfate ions appeared to inhibit dolomite formation above 2 mM concentration (versus 28 mM in modern seawater). Recently, culture experiments have demonstrated that sulfate-reducing bacteria mediate the precipitation of dolomite at Earth surface conditions in the presence of sustained sulfate ion concentrations [2,3]. Additionally, in a number of modern hypersaline environments, dolomite forms from solutions with high sulfate ion concentrations (2 to 70 times seawater). These observations suggest that the experimentally observed sulfate-ion inhibition [1] may not apply to all ancient dolomite formation. Here, we report aerobic culture experiments conducted at low temperatures (25 and 35 oC) and variable sulfate ion concentrations (0, 0.5, 1 and 2 x seawater values) using moderately halophilic bacteria, Halomonas meridiana. After an incubation period of 15 days, experiments at 35 oC with variable sulfate ion concentrations (0, 0.5 x and seawater values) contained crystals of Ca-dolomite and stochiometric dolomite. The experiment at 35 oC with 2 x seawater sulfate ion concentration produced dolomite crystals after 20 days of incubation. In a parallel set of experiments at 25 oC, precipitation of dolomite was observed after 25 days of incubation in cultures with variable sulfate ion concentrations (0, 0.5 x and seawater values). In the culture with 2 x seawater sulfate ion concentration, dolomite crystals were observed after 30 days. Our study demonstrates that halophilic bacteria (or heterotrophic microorganisms), which do not require sulfate ions for metabolism, can mediate dolomite precipitation in the presence of sulfate ions. Apparently, microbial dolomite precipitation is not intrinsically linked to any particular group of organisms or specific metabolic processes or even specific environment. Furthermore, because heterotrophic microorganisms appear to be able to mediate microbial dolomite precipitation with or without sulfate ions in the media, our results indicate that the kinetic inhibition effect of sulfate ions can be overcome under specific sedimentary conditions. The present study adds a new insight to the dolomite problem, which could lead to a better clarification of the mechanism(s) involved in the massive dolomite formation observed in the geological record. References: [1] Baker, P.A., and Kastner, M., (1981), Science, 213, 214-216. [2] Vasconcelos, C., McKenzie, J.A., Bernasconi, S., Grujic, D. and Tien, A.J., (1995), Nature 377, 220-222.. [3] Warthmann R., van Lith Y., Vasconcelos C., McKenzie J.A. and Karpoff A.M., (2000), Geology 28, 1091-1094.

Sanchez-Roman, M.; McKenzie, J. A.; Vasconcelos, C.; Rivadeneyra, M.

2005-12-01

239

Exopolymeric substances of sulfate-reducing bacteria: Interactions with calcium at alkaline pH and implication for formation of carbonate minerals  

Microsoft Academic Search

Sulfate-reducing bacteria (SRB) have been recognized as key players in the precipitation of calcium carbonate in lithifying microbial communities. These bacteria increase the alkalinity by reducing sulfate ions, and consuming organic acids. SRB also produce copious amounts of exopolymeric substances (EPS). All of these processes influence the morphology and mineralogy of the carbonate minerals. Interactions of EPS with metals, calcium

O. BRAISSANT; A. W. DECHO; C. DUPRAZ; C. GLUNK; K. M. PRZEKOP; P. T. VISSCHER

2007-01-01

240

CLOUD AND CHEMICAL PATHWAY CHARACTERIZATION OF THE NONLINEAR RESPONSE OF SULFUR DEPOSITION AND SULFATE AIR CONCENTRATIONS TO CHANGES IN SO2 EMISSIONS IN THE RADM  

EPA Science Inventory

The aqueous-phase chemistry that occurs in both precipitating and nonprecipitating clouds provides a major mechanism for the conversion of S02 to sulfate in the troposphere. ccording to the Regional Acid Deposition Model (RADM), cloud production of sulfate dominates over gas-phas...

241

Fatal barium chloride poisoning: four cases report and literature review.  

PubMed

Barium is an alkaline earth metal which has a variety of uses including in the manufacturing industry and in medicine. However, adverse health effects and fatalities occur due to absorption of soluble barium compounds, notably the chloride, nitrate, and hydroxide, which are toxic to humans. Although rare, accidental and suicidal modes of poisoning are sporadically reported in the literature.We describe 4 cases of poisoning due to barium chloride in China. In witnessed cases, severe gastrointestinal symptoms, hypokalemia leading to muscle weakness, cardiac arrhythmias, and respiratory failure were noted. Autopsy showed some nonspecific but common findings, such as subendocardial hemorrhage in the ventricles, visceral petechiae, and fatty changes in the liver. Interestingly, microscopic examination showed degenerative changes and amorphous, flocculent foamy materials in the renal tubules. Toxicology was relevant for barium in blood and tissues. Three of the cases were accidental and 1 homicidal in nature. A round-up of relevant literature on fatal barium compounds poisoning is also provided. Forensic pathologists should be aware of the clinical presentations of barium compound poisoning and especially look for any evidence of hypokalemia. Still, postmortem toxicological and histological studies are essential for an accurate identification of the cause of death. PMID:23629399

Ananda, Sunnassee; Shaohua, Zhu; Liang, Liu

2013-06-01

242

Vitrification of high sulfate wastes  

SciTech Connect

The US Department of Energy (DOE) through the Mixed Waste Integrated Program (MWIP) is investigating the application of vitrification technology to mixed wastes within the DOE system This work involves identifying waste streams, laboratory testing to identify glass formulations and characterize the vitrified product, and demonstration testing with the actual waste in a pilot-scale system. Part of this program is investigating process limits for various waste components, specifically those components that typically create problems for the application of vitrification, such as sulfate, chloride, and phosphate. This work describes results from vitrification testing for a high-sulfate waste, the 183-H Solar Evaporation Basin waste at Hanford. A low melting phosphate glass formulation has been developed for a waste stream high in sodium and sulfate. At melt temperatures in the range of 1,000 C to 1,200 C, sulfate in the waste is decomposed to gaseous oxides and driven off during melting, while the remainder of the oxides stay in the melt. Decomposition of the sulfates eliminates the processing problems typically encountered in vitrification of sulfate-containing wastes, resulting in separation of the sulfate from the remainder of the waste and allowing the sulfate to be collected in the off-gas system and treated as a secondary waste stream. Both the vitreous product and intentionally devitrified samples are durable when compared to reference glasses by TCLP and DI water leach tests. Simple, short tests to evaluate the compatibility of the glasses with potential melter materials found minimal corrosion with most materials.

Merrill, R.A.; Whittington, K.F.; Peters, R.D.

1994-09-01

243

Biological sulfate reduction using molasses as a carbon source.  

PubMed

The feasibility of using a laboratory-scale upflow anaerobic sludge blanket process for sulfate reduction with molasses as a carbon source was demonstrated. Competition between methane-producing bacteria (MPB) and sulfate-reducing bacteria (SRB) was influenced by the chemical oxygen demand-to-sulfur (COD:S) ratio in the feed. Sulfate removal greater than 80% could be achieved at COD:S greater than 10 when MPB predominated. Activity of MPB and SRB was inhibited at a dissolved sulfide concentration of approximately 200 mg/L. Competition between MPB and SRB was intense as the COD:S was reduced from 5 to 2. Further reduction in the COD:S to 0.7 led to the formation of sulfidogenic granules. The COD removal decreased to approximately 30% at a COD:S less than 2 because of accumulation of sulfurous precipitates and the nonbiodegradable portion of molasses in the sludge. Reduced gas production rates further imposed limitations on diffusion of the organic substrate into granules. Sulfidogenic process operation yielded sulfate removal as great as 70% at a COD:S of approximately 3.5. PMID:11558296

Annachhatre, A P; Suktrakoolvait, S

2001-01-01

244

Inhibition of sulfate-reducing and methanogenic activities of anaerobic sewer biofilms by ferric iron dosing.  

PubMed

Ferric iron is commonly used for sulfide precipitation in sewers, thus achieving corrosion and odour control. Its impact on the activities of sulfate-reducing bacteria and methanogens in anaerobic sewer biofilms is investigated in this study. Two lab-scale rising main sewer systems fed with real sewage were operated for 8 months. One received Fe(3+) dosage (experimental system) and the other was used as a control. In addition to precipitating sulfide from bulk water, Fe(3+) dosage was found to significantly inhibit sulfate reduction and methane production by sewer biofilms. The experimental reactor discharged an effluent containing a higher concentration of sulfate and a lower concentration of methane in comparison with the reference reactor. Batch experiments showed that the addition of ferric ions reduced the sulfate reduction and methane production rates of the sewer biofilms by 60% and 80%, respectively. The batch experiments further showed that Fe(3+) dosage changed the final products of sulfate reduction with sulfide accounting for only 54% of the sulfate reduced. The other products could not be confirmed, but were not dissolved inorganic sulfur species such as sulfite or thiosulfate. The results suggest the addition of Fe(3+) at upstream locations would minimize the ferric salts required for achieving the same level of sulfide removal. Fe(3+) dosing could also substantially reduce the formation of methane, a potent greenhouse gas, in sewers. PMID:19576610

Zhang, Lishan; Keller, Jürg; Yuan, Zhiguo

2009-09-01

245

Effects of thermal sulfate reduction on permeability distributions of the Norphlet Formation  

SciTech Connect

Framework grain coatings are common in the Norphlet. Clay coatings are present throughout the depth range (16,000 to 22,000 ft) over which significant variations of permeability occur. Pyrobitumen coatings occur within the deep, low-permeability interval (approximately 18,000-20,000 ft) and the deeper (greater than 20,000 ft), more permeable interval. Both types of coatings may be important in preserving porosity during portions of the burial history of the Norphlet sandstones; however, their occurrence does not correlate with observed variations in permeability. Diagenetic reactions associated with thermal sulfate reduction provide a mechanism for the dissolution of carbonate cements in deep zones characterized by enhanced permeabilities. Protons generated from dissociation of H{sub 2}S produced during sulfate reduction results in the dissolution of carbonate cements. To be effective, this process must remove cements that precipitated after grain coatings. Uncoated quartz grains produce quartz overgrowths. Vertical permeability distributions within the Norphlet suggest that early and intermediate diagenetic carbonate and sulfate cements, sourced from the intercalated, interdunal pond strata, were redistributed throughout the dune sands. Portions of carbonate cements were either dissolved or the extent of their precipitation was reduced as thermal decarboxylation was closely followed by the initiation of sulfate reduction. Hence, variations in Norphlet permeability distributions are in part the result of diagenetic reactions associated with thermal sulfate reduction and, therefore, can be predicted using kinetic modeling of sulfate reaction.

Dunn, T.L.; Surdam, R.C. (Univ. of Wyoming, Laramie (United States))

1991-03-01

246

Synthesis of single-crystal barium titanium isopropoxide complex to form barium titanate  

SciTech Connect

Single-crystal barium titanate double alkoxide complex with a composition presumed to be BaTi(OCH(CH[sub 3])[sub 2])[sub 6][center dot]xC[sub 6]H[sub 6] was successfully synthesized in this work. The crystal was converted to BaTiO[sub 3] at 100 C. The preparation of the oxides via single crystals of metal alkoxides has some advantage over the well-known sol-gel method in that it results in oxides with well-defined and homogeneous compositions at the atomic level and in fine particle sizes, smaller than 50 nm.

Suyama, Yoko (Japan Fine Ceramic Center, Nagoya (Japan)); Nagasawa, Mitsuru (Toyota Technological Inst., Nagoya (Japan))

1994-02-01

247

Rock Star Precipitation  

NSDL National Science Digital Library

In this lesson, the student will play the role of a famous musician planning a world tour with performances in outdoor amphitheaters in Chile, Venezuela, Greenland, and Maine (USA). Based on Monthly Precipitation Data for 2006 from MyNASAData website, the student will evaluate changes in monthly precipitation levels, draw conclusions about how precipitation data will determine dates for a world tour and infer locations and months best for performing live outdoor concert.

248

Evaporation, Condensation, and Precipitation  

NSDL National Science Digital Library

After completion of this project students should have an understanding of evaporation, condensation, and precipitation in the water cycle. Use the websites provided to answer the questions. Record your answers on the spreadsheet provided. Do you understand how the water cycle works? Begin by watching this short video about the water cycle.water cycle video Use the website to define condensation, precipitation, and evaporation?water cycle List the different types of precipitation from the site.types of precipitation Follow the directions to the experiment on this website to get a better understanding of how evaporation takes ...

Brown, Miss

2009-10-21

249

Mesoscale Banded Precipitation  

NSDL National Science Digital Library

Precipitation frequently falls and accumulates in discrete bands with accumulations that vary markedly over short distances. This module examines several mechanisms that result in mesoscale banded precipitation, focusing primarily on processes at work in midlatitude cyclones. The module starts with a review of the Norwegian and conveyor belt cyclone models. Then several banding processes are examined in detail, including deformation/frontogenesis, the Trowal (Trough of Warm Air Aloft), frontal merger, CSI/slantwise convection, and melting/evaporation-induced circulations. The module concludes with discussions of the representation of banded precipitation by NWP models and the detection of banded precipitation with satellite sensors.

2014-09-14

250

Prospects for Barium Tagging in Gaseous Xenon  

SciTech Connect

Tagging events with the coincident detection of a barium ion would greatly reduce the background for a neutrino-less double beta decay search in xenon. This paper describes progress towards realizing this goal. It outlines a source that can produce large quantities of Ba++ in gas, shows that this can be extracted to vacuum, and demonstrates a mechanism by which the Ba++ can be efficiently converted to Ba+ as required for laser identification. It is clear from this study that electrospray is a convenient mechanism for producing Ba++ is gas at atmospheric pressure. It is likely that the source will perform just as effectively at higher pressures. Even though the source region has water vapour and methanol vapour at the 0.3% level, there is no evidence for molecular formation. The use of TEA offers an effective method to achieve the charge state conversion. The overall design of the ion extraction from high pressure to vacuum is very similar to the scheme proposed for the final detector and this appears to work well although the efficiency is not yet determined.

Sinclair, D.; /Carleton U. /TRIUMF; Rollin, E.; /Carleton U.; Smith, J.; /Carleton U.; Mommers, A.; /Ottawa U.; Ackerman, N.; /SLAC; Aharmim, B.; /Laurentian U.; Auger, M.; /Bern U., LHEP; Barbeau, P.S.; /Stanford U., Phys. Dept.; Benitez-Medina, C.; /Colorado State U.; Breidenbach, M.; /SLAC; Burenkov, A.; /Moscow, ITEP; Cook, S.; /SLAC; Coppens, A.; /Carleton U.; Daniels, T.; /Massachusetts U., Amherst; DeVoe, R.; /Stanford U., Phys. Dept.; Dobi, A.; /Maryland U.; Dolinski, M.J.; Donato, K.; /Stanford U., Phys. Dept.; Fairbank, W., Jr.; /Colorado State U.; Farine, J.; /Laurentian U.; Giroux, G.; /Bern U., LHEP /Carleton U. /Stanford U., Phys. Dept. /Carleton U. /Laurentian U. /Carleton U. /SLAC /Indiana U. /Indiana U., CEEM /Korea U. /Stanford U., Phys. Dept. /SLAC /Alabama U. /Colorado State U. /Stanford U., Phys. Dept. /Alabama U. /SLAC /Stanford U., Phys. Dept. /Alabama U. /Massachusetts U., Amherst /SLAC /Alabama U. /SLAC /Maryland U. /Moscow, ITEP /Stanford U., Phys. Dept. /Maryland U. /Bern U., LHEP /Laurentian U. /SLAC /Maryland U.

2012-05-03

251

Co-doped Barium Phosphate Glass  

NASA Astrophysics Data System (ADS)

Co-doping of a P2O5:BaO glass matrix with divalent tin and trivalent samarium ions has been realized by the melt-quenching technique with the purpose of investigating the material's luminescent properties. Photoluminescence excitation spectra obtained by monitoring Sm3+ 4G5/2 emission showed a broad excitation band around 290 nm (absent in a Sm3+-doped reference), typical of donor/acceptor energy transfer. Under such excitation, the material exhibits a reddish-white emission. Time-resolved spectra recorded under the 290-nm excitation (non-resonant with Sm3+ excitation peaks) exposed a broad blue-white band characteristic of twofold-coordinated Sn centers and orange-red emission bands of Sm3+ ions, which appeared well separated in time in accord with their emission decay dynamics. Consequently, the data indicate that light absorption occurs at Sn centers (donors) followed by energy transfer to samarium ions (acceptors) which results in populating the 4G5/2 emitting state in Sm3+. Energy transfer pathways likely resulting in the sensitization of Sm3+ photoluminescence are discussed. Results are put into context in terms of the potential of SnO and rare-earth co-doped barium phosphate glasses for use in white light-emitting devices.

Jiménez, J. A.

2014-09-01

252

High H? ionic conductivity in barium hydride  

NASA Astrophysics Data System (ADS)

With hydrogen being seen as a key renewable energy vector, the search for materials exhibiting fast hydrogen transport becomes ever more important. Not only do hydrogen storage materials require high mobility of hydrogen in the solid state, but the efficiency of electrochemical devices is also largely determined by fast ionic transport. Although the heavy alkaline-earth hydrides are of limited interest for their hydrogen storage potential, owing to low gravimetric densities, their ionic nature may prove useful in new electrochemical applications, especially as an ionically conducting electrolyte material. Here we show that barium hydride shows fast pure ionic transport of hydride ions (H?) in the high-temperature, high-symmetry phase. Although some conductivity studies have been reported on related materials previously, the nature of the charge carriers has not been determined. BaH2 gives rise to hydride ion conductivity of 0.2 S cm?1 at 630 °C. This is an order of magnitude larger than that of state-of-the-art proton-conducting perovskites or oxide ion conductors at this temperature. These results suggest that the alkaline-earth hydrides form an important new family of materials, with potential use in a number of applications, such as separation membranes, electrochemical reactors and so on.

Verbraeken, Maarten C.; Cheung, Chaksum; Suard, Emmanuelle; Irvine, John T. S.

2015-01-01

253

High H(-) ionic conductivity in barium hydride.  

PubMed

With hydrogen being seen as a key renewable energy vector, the search for materials exhibiting fast hydrogen transport becomes ever more important. Not only do hydrogen storage materials require high mobility of hydrogen in the solid state, but the efficiency of electrochemical devices is also largely determined by fast ionic transport. Although the heavy alkaline-earth hydrides are of limited interest for their hydrogen storage potential, owing to low gravimetric densities, their ionic nature may prove useful in new electrochemical applications, especially as an ionically conducting electrolyte material. Here we show that barium hydride shows fast pure ionic transport of hydride ions (H(-)) in the high-temperature, high-symmetry phase. Although some conductivity studies have been reported on related materials previously, the nature of the charge carriers has not been determined. BaH2 gives rise to hydride ion conductivity of 0.2 S cm(-1) at 630 °C. This is an order of magnitude larger than that of state-of-the-art proton-conducting perovskites or oxide ion conductors at this temperature. These results suggest that the alkaline-earth hydrides form an important new family of materials, with potential use in a number of applications, such as separation membranes, electrochemical reactors and so on. PMID:25485988

Verbraeken, Maarten C; Cheung, Chaksum; Suard, Emmanuelle; Irvine, John T S

2015-01-01

254

Pyroelectric properties of barium strontium titanate films: Effect of thermal M. W. Cole,2  

E-print Network

Pyroelectric properties of barium strontium titanate films: Effect of thermal stresses J. Zhang,1 M pyroelectric properties of 001 -textured polycrystalline barium strontium titanate BaxSr1-xTiO3, BST films

Alpay, S. Pamir

255

Cooling laser system for quantum computing with barium-137 ions Tom Chartrand  

E-print Network

Cooling laser system for quantum computing with barium-137 ions Tom Chartrand Department of Physics for essentially any application. We have been trapping 137-barium with this end in mind. The odd isotope has

Blinov, Boris

256

Tracking Phaselock Loop Characteristics with a VCO Using a Barium Strontium Titanate (BST)  

E-print Network

Tracking Phaselock Loop Characteristics with a VCO Using a Barium Strontium Titanate (BST) Thin University, Raleigh, NC-27695-7919,USA, Ph: +1-919-767-3277, Email: avictor@harris.com Abstract -- Barium

257

Impact of thermal strain on the dielectric constant of sputtered barium strontium titanate thin films  

E-print Network

Impact of thermal strain on the dielectric constant of sputtered barium strontium titanate thin, California 93106 Received 6 November 2001; accepted for publication 10 January 2002 Barium strontium titanate

York, Robert A.

258

Millimeter wave phase shifter based on ferromagnetic resonance in a hexagonal barium ferrite thin film  

E-print Network

Millimeter wave phase shifter based on ferromagnetic resonance in a hexagonal barium ferrite thin of an M-type barium ferrite BaM thin film prepared by pulsed laser deposition and a coplanar waveguide

259

Über die bei der Uranspaltung auftretenden kurzlebigen Barium und Lanthan-Isotope  

Microsoft Academic Search

Zusammenfassung 1. Das früher für ein primäres Spaltprodukt des Urans gehaltene sog. „14-Minuten-Barium“ wurde auch im „aktiven Niederschlag“ aus hochemanierendem Uran nachgewiesen. Es entsteht also, wie die anderen bisher bekannten Barium-Isotope, ebenfalls aus Xenon.

Otto Hahn; Fritz Strassmann

1942-01-01

260

Acceleration of barium ions near 8000 km above an aurora  

NASA Technical Reports Server (NTRS)

A barium shaped charge, named Limerick, was released from a rocket launched from Poker Flat Research Range, Alaska, on March 30, 1982, at 1033 UT. The release took place in a small auroral breakup. The jet of ionized barium reached an altitude of 8100 km 14.5 min after release, indicating that there were no parallel electric fields below this altitude. At 8100 km the jet appeared to stop. Analysis shows that the barium at this altitude was effectively removed from the tip. It is concluded that the barium was actually accelerated upward, resulting in a large decrease in the line-of-sight density and hence the optical intensity. The parallel electric potential in the acceleration region must have been greater than 1 kV over an altitude interval of less than 200 km. The acceleration region, although presumably auroral in origin, did not seem to be related to individual auroral structures, but appeared to be a large-scale horizontal structure. The perpendicular electric field below, as deduced from the drift of the barium, was temporally and spatially very uniform and showed no variation related to individual auroral structures passing through.

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

1984-01-01

261

Dissolved Organic Carbon In Precipitation At A Coastal Rural Site  

NASA Astrophysics Data System (ADS)

Dissolved organic carbon (DOC) is a ubiquitous component of precipitation. This DOC is a complex mixture of compounds from biogenic and anthropogenic sources. The amount and chemistry of the DOC in precipitation has been studied for a variety of reasons: as a source of acidity, as a source of C to marine and terrestrial ecosystems, or to track the fate of individual compounds or pollutants. In most cases, past studies have focused on particular compounds or a limited number of precipitation events. Very little is known about the temporal trends in DOC or the relationship between DOC and other constituents of precipitation. We collected precipitation events for more than five years at a rural coastal site in New Hampshire. We evaluated the seasonal patterns and compared the DOC concentrations to other typical measures of the wet atmospheric deposition (ammonium, nitrate, sulfate, and chloride). In addition, we compared the DOC in precipitation to the concentrations of various organic constituents of the atmosphere. The volume weighted mean C concentration was 0.75 mg C/L with concentrations in the summer significantly higher than in the other three seasons. The DOC concentration was most strongly associated with ammonium concentrations (r=0.81), but was also significantly related to nitrate (r=0.50) and sulfate (r=0.63) concentrations. There was no significant association between DOC and chloride concentrations. Preliminary regression tree analysis suggests that the DOC concentration in precipitation was best predicted by the atmospheric concentration of methyl vinyl ketone, an oxidation product of isoprene. These results suggest that both terrestrial biogenic and anthropogenic sources may be important precursors to the C removed from the atmosphere during precipitation events.

Liptzin, D.; Daley, M.; Sive, B. C.; Talbot, R. W.; McDowell, W. H.

2013-12-01

262

Catalytic activity and magnetic properties of barium hexaferrite prepared from barite ore  

Microsoft Academic Search

Barium hexaferrite (BaFe12O19) has traditionally been used in permanent magnets and more recently used for high density magnetic recording. The classical ceramic method for the preparation of barium hexaferrite consists of firing mixture of chemical grade iron oxide and barium carbonate at high temperature. In this paper a mixture of chemical grade hematite, barium oxide and predetermined mixtures of iron

M. M. Hessien; M. H. Khedr

2007-01-01

263

Time constraints on sulfate-related diagenesis, Capitan Reef Complex, west Texas and New Mexico  

SciTech Connect

Petrographic, paleomagnetic, and outcrop studies of the middle Capitan Reef Complex in the Guadalupe Mountains have provided time constraints on diagenetic events and demonstrated the crucial role of calcium sulfate. Sulfate emplacement occurred at an early stage. The sulfate emplacement post-dated and replaced syndepositional marine margins and lath forms demonstrate replacement was by anhydrite rather then gypsum. Fabric-selective dolomitization and kaolinite precipitation derived from reworking shelf evaporite sequences moving downdip during early stages of drawdown within the Delaware basin. A second period of brine migration causing sulfate emplacement and dolomitization, occurred as the Delaware basin gradually filled with the Castile evaporites, when all remaining porosity within the Capitan shelf margin became indurated by calcium sulfate-laden fluids. This caused pervasive dolomitization, particularly in the lower foreslope, with formation of dolomite rhombs and overgrowths on earlier dolomitized marine cements, coeval with replacive clusters of anhydrite. Most porosity was plugged, some with syndepositional marine cements, but the greater proportion with evaporites until uplift in the Tertiary. Then a meteoric groundwater system became established with subsequent sulfate dissolution. Minor sulfate reduction formed iron sulfides. This oxidized to hematite, which was enclosed within a first generation of zoned calcite spar along some pore margins. Most hematite has a paleomagnetic age of 20 Ma, although minor hematite formation continues to the present. A second, also zoned, coarser calcite spar generation was followed by the latest nonluminescent calcite spar. These calcite spars form the vast bulk of that visible at outcrop.

Darke, G. (Univ. of Newcastle upon Tyne (England)); Harwood, G. (Univ. of East Anglia, Norwich (England))

1990-05-01

264

Could binary mixture of Nd-Ni ions control the electrical behavior of strontium-barium M-type hexaferrite nanoparticles?  

SciTech Connect

Research highlights: {yields} Strontium-barium hexaferrites (Sr{sub 0.5}Ba{sub 0.5}Fe{sub 12}O{sub 19}) in single magnetoplumbite phase solid structure are synthesized by the co-precipitation method. {yields} Structural and electrical properties of Nd-Ni substituted ferrites are investigated. {yields} These ferrite materials possess high electrical resistivity (108 {Omega} cm) that is essential to curb the eddy current loss, which is pre-requisite for surface mount devices. -- Abstract: Cationic substitution in M-type hexaferrites is considered to be an important tool for modification of their electrical properties. This work is part of our comprehensive study on the synthesis and characterization of Nd-Ni doped strontium-barium hexaferrite nanomaterials of nominal composition Sr{sub 0.5}Ba{sub 0.5-x}Nd{sub x}Fe{sub 12-y}Ni{sub y}O{sub 19} (x = 0.00-0.10; y = 0.00-1.00). Doping with this binary mixture modulates the physical and electrical properties of strontium-barium hexaferrite nanoparticles. Structural and electrical properties of the co-precipitated ferrites are investigated using state-of-the-art techniques. The results of X-ray diffraction analysis reveal that the lattice parameters and cell volume are inversely related to the dopant content. Temperature dependent DC-electrical resistivity measurements infer that resistivity of strontium-barium hexaferrites decreases from 1.8 x 10{sup 10} to 2.0 x 10{sup 8} {Omega} cm whereas the drift mobility, dielectric constant and dielectric loss tangent are directly related to the Nd-Ni content. The results of the study demonstrate a relationship between the modulation of electrical properties of substituted ferrites and nature of cations and their lattice site occupancy.

Iqbal, Muhammad Javed, E-mail: mjiqauchem@yahoo.com [Surface and Solid State Chemistry Laboratory, Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Farooq, Saima [Surface and Solid State Chemistry Laboratory, Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)] [Surface and Solid State Chemistry Laboratory, Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

2011-05-15

265

Formation of a Precipitate  

NSDL National Science Digital Library

Learners create hard water by mixing Epsom salt and water. Then they compare what happens when soap solution is mixed with hard water and regular water. The precipitate that forms from soap and hard water resembles soap but isn't. Learners then design an experiment to compare this precipitate to soap to distinguish them from each other.

Kessler, James H.; Galvan, Patricia M.

2007-01-01

266

Morphology of nightside precipitation  

Microsoft Academic Search

Considerable information on the state of the magnetosphere is embedded in the structure of nightside charged particle precipitation. To reduce ambiguity and maximize the geophysically significant information extracted, a detailed scheme for quantitatively classifying nightside precipitation is introduced. The proposed system, which includes operational definitions and which has been automated, consists of boundary 1, the ``zero-energy'' convection boundary (often the

Patrick T. Newell; Yasha I. Feldstein; Yuri I. Galperin; Ching-I. Meng

1996-01-01

267

Technical development: CT colonography without cathartic cleansing and with barium as the sole tagging agent  

Microsoft Academic Search

The purpose of this study was to perform CT colonography (CTC) without cathartic colon cleansing. Four groups of 3 patients were prepared the day before CTC with a dedicated low residue diet, a hydration control allowing 2 liters of fluid intake and barium as tagging agent. Four different barium regimens were investigated. Groups 1 and 3 ingested barium over 1

Philippe Lefere; Stefaan Gryspeerdt; Marc Baekelandt; Bartel Van Holsbeeck

2004-01-01

268

Dielectric tunability of graded barium strontium titanate multilayers: Effect of thermal strains  

E-print Network

Dielectric tunability of graded barium strontium titanate multilayers: Effect of thermal strains M TEC of a multilayered barium strontium titanate Ba1-ySryTiO3 BST ferroelectric heterostructure such as barium strontium titanate Ba1-ySryTiO3 BST have emerged as leading candidates for such applications due

Alpay, S. Pamir

269

Enhanced Sintering of Yttrium-Doped Barium Zirconate by Addition of ZnO  

E-print Network

Enhanced Sintering of Yttrium-Doped Barium Zirconate by Addition of ZnO Peter Babilo and Sossina M properties of doped barium zirconate have been examined. With the use of zinc ox- ide as a sintering aid, Ba of the material under flowing CO2 showed ZnO-modified barium zirconate to exhibit excellent chemical stability

Haile, Sossina M.

270

Spectroscopy of Ba and Ba+ deposits in solid xenon for barium tagging in  

E-print Network

Spectroscopy of Ba and Ba+ deposits in solid xenon for barium tagging in nEXO B. Mong,1, 2 S. Cook, Vermillion SD, USA (Dated: October 13, 2014) Progress on a method of barium tagging for the nEXO double beta decay experiment is reported. Absorption and emission spectra for deposits of barium atoms and ions

Gratta, Giorgio

271

Synthesis and Structural Diversity of Barium (N,N-Dimethylamino)diboranates  

E-print Network

Synthesis and Structural Diversity of Barium (N,N-Dimethylamino)diboranates Scott R. Daly, Brian J. The reaction of 1 or 1 with Lewis bases that bind more strongly to barium than diethyl ether results that several of the barium complexes are monomeric in the solid state, none is appreciably volatile up to 200

Girolami, Gregory S.

272

Influence of Ba content on grain size and dynamics of crystallization in barium ferrite thin films  

E-print Network

Influence of Ba content on grain size and dynamics of crystallization in barium ferrite thin films of the crystallization process, which ultimately determines the grain size, were studied in barium ferrite thin films. Rapid thermal annealing was used to crystallize the amorphous as-deposited barium ferrite films

Laughlin, David E.

273

A comparison between excess barium and barite as indicators of carbon export  

E-print Network

A comparison between excess barium and barite as indicators of carbon export Meagan Eagle and Adina in many paleoproductivity studies. Barite, the main carrier of particulate barium in the water column in some locations. We demonstrate that Baexcess (total barium minus the fraction associated

Paytan, Adina

274

Barium ferrite thin film media with perpendicular c-axis orientation and small grain size  

E-print Network

Barium ferrite thin film media with perpendicular c-axis orientation and small grain size Zailong, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 Barium ferrite thin films with perpendicular c conditions. The c-axis orientation of barium ferrite thin films is most sensitive to the oxygen partial

Laughlin, David E.

275

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

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Barium azide-50 percent or more water wet. 173...Other Than Class 1 and Class 7 § 173.182 Barium azide—50 percent or more water wet. Barium azide—50 percent or more water wet,...

2011-10-01

276

MNRAS 428, 32523261 (2013) doi:10.1093/mnras/sts270 Barium abundances in Cepheids  

E-print Network

MNRAS 428, 3252­3261 (2013) doi:10.1093/mnras/sts270 Barium abundances in Cepheids S. M. Andrievsky; in original form 2012 August 28 ABSTRACT We derived the barium atmospheric abundances for a large sample to 15 kpc, so it is appropriate to investigate the existence of radial barium abundance gradients

Maciel, Walter Junqueira

277

Journal of Crystal Growth 300 (2007) 330335 Growth and optical property characterization of textured barium  

E-print Network

of textured barium titanate thin films for photonic applications Matthew J. DickenÃ?, Kenneth Diest, Young. D.P. Norton Available online 21 December 2006 Abstract We have investigated the growth of barium layers on amorphous and silicon substrates. Growth of highly oriented barium titanate films

Atwater, Harry

278

Discrete Barium Strontium Titanate (BST) Thin-Film Interdigital Varactors on Alumina: Design, Fabrication, Characterization, and  

E-print Network

Discrete Barium Strontium Titanate (BST) Thin-Film Interdigital Varactors on Alumina: Design, Raleigh, NC-27695-7914, USA. Email:jayeshnath@ieee.org Abstract -- Discrete Barium Strontium Titanate (BST, capacitors, BST, ferroelectric, thin-film, barium strontium titanate, bandpass filter, IP3, ACPR, temperature

279

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Barium manganese oxide (BaMnO3). 721.10010...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3 ). (a...The chemical substance identified as barium manganese oxide (BaMnO3 )...

2013-07-01

280

Effect of Microwave Frequency on Hydrothermal Synthesis of Nanocrystalline Tetragonal Barium Titanate  

E-print Network

Effect of Microwave Frequency on Hydrothermal Synthesis of Nanocrystalline Tetragonal Barium, 2007; ReVised Manuscript ReceiVed: April 29, 2008 Nanocrystalline tetragonal barium titanate (BaTiO3. The dependence of properties of barium titanate on microwave frequency could be due to different transverse

Dutta, Prabir K.

281

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Barium manganese oxide (BaMnO3). 721.10010...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3 ). (a...The chemical substance identified as barium manganese oxide (BaMnO3 )...

2014-07-01

282

Noncollinear Optical Frequency Doubling in Strontium Barium Niobate Arthur R. Tunyagi, Michael Ulex, and Klaus Betzler*  

E-print Network

Noncollinear Optical Frequency Doubling in Strontium Barium Niobate Arthur R. Tunyagi, Michael Ulex of a novel noncollinear optical second-harmonic generation mechanism is reported. In strontium barium niobate mechanism which we detected in crystals of strontium barium niobate (SBN)--cone-shaped second

Osnabrück, Universität

283

Spectroscopy of Eu3+ ions in congruent strontium barium niobate crystals  

E-print Network

Spectroscopy of Eu3+ ions in congruent strontium barium niobate crystals Ã?. Andresen, A.-N. Bahar properties of single crystals of strontium barium niobate, grown from the congruently melting composition, electro-optic, pho- torefractive, and dielectric properties, the solid solution strontium barium niobate

Osnabrück, Universität

284

Optogalvanic detection of barium high-lying levels with a two-step pulsed laser excitation  

E-print Network

L-513 Optogalvanic detection of barium high-lying levels with a two-step pulsed laser excitation P barium have been investigated by using a two-step pulsed laser excitation combined with an optogalvanic number for the ground state. In barium the ground level has a J = 0 value, so with a two- photon process

Boyer, Edmond

285

75 FR 36629 - Barium Chloride From the People's Republic of China: Continuation of Antidumping Duty Order  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Administration [A-570-007] Barium Chloride From the People's Republic...revocation of the antidumping duty order on barium chloride from the People's Republic...review of the antidumping duty order on barium chloride from the PRC pursuant to...

2010-06-28

286

Processing of yttrium-doped barium zirconate for high proton conductivity  

E-print Network

Processing of yttrium-doped barium zirconate for high proton conductivity Peter Babilo Materials the transport properties of yttrium-doped barium zirconate (BYZ) have been explored, with the aim of attaining­100 nm) and high-temperature sintering (1600 °C) in the presence of excess barium were essential

287

M-type barium hexaferrite synthesis and characterization for phase shifter applications  

E-print Network

M-type barium hexaferrite synthesis and characterization for phase shifter applications A. T. Wise; published online 13 April 2011) M-type barium hexaferrite films have been grown by liquid phase epitaxy half a percent. VC 2011 American Institute of Physics. [doi:10.1063/1.3559471] Since M-type barium

McHenry, Michael E.

288

Distribution of barium in the Weddell Gyre: Impact of circulation and biogeochemical processes  

E-print Network

of barium in the Weddell Gyre: Impact of circulation and biogeochemical processes M. Hoppemaa,1 , F@vub.ac.be Key words : Barium; silicate; geochemical cycle; (Southern Ocean, Weddell Sea) Manuscript Click here barium (Bad) has been augmented significantly with two sections across the Weddell Gyre sampled

Paris-Sud XI, Université de

289

Phase associations of barium in marine sediments Meagan Eagle Gonneea *, Adina Paytan 1  

E-print Network

Phase associations of barium in marine sediments Meagan Eagle Gonneea *, Adina Paytan 1 Department 2006 Abstract Barium (Ba) is associated with various phases in marine sediments, including carbonates-export productivity. D 2005 Elsevier B.V. All rights reserved. Keywords: Barium; Barite; Marine sediment; Sedimentary

Paytan, Adina

290

Defect Chemistry of Yttrium-Doped Barium Zirconate: A Thermodynamic Analysis of Water Uptake  

E-print Network

Defect Chemistry of Yttrium-Doped Barium Zirconate: A Thermodynamic Analysis of Water Uptake-based SOFCs.3 Of known proton conducting oxides, yttrium-doped barium zirconate (BYZ) is particularly mobile species. Doping with trivalent yttrium onto the tetravalent zirconium in barium zirconate

291

Barium Titanate Nanoparticles in Block Copolymer Tu Lee,*,, Nan Yao, Hiroaki Imai,, and Ilhan A. Aksay,  

E-print Network

Barium Titanate Nanoparticles in Block Copolymer Tu Lee,*,, Nan Yao, Hiroaki Imai,, and Ilhan A-polybutadiene-polystyrene (Kraton D1102). The barium titanated Kraton thin film had remnants of the cylindrical morphology of a plain Kraton thin film with an interdomain spacing of 23 nm. The procedure of barium titanation

Aksay, Ilhan A.

292

The effect of stress on the dielectric properties of barium strontium titanate thin films  

E-print Network

The effect of stress on the dielectric properties of barium strontium titanate thin films T. M Barium strontium titanate thin films are being developed as capacitors in dynamic random access memories to their large permittivities, barium strontium titan- ate BST bulk ceramics have long been used to make high

Suo, Zhigang

293

Introduction Strontium Barium Niobate k-Space Spectroscopy Results Conclusions Unraveling Relaxor Phase Transitions by  

E-print Network

Introduction Strontium Barium Niobate k-Space Spectroscopy Results Conclusions Unraveling Relaxor 2009 WILLIAMSBURG WORKSHOP ON FUNDAMENTAL PHYSICS OF FERROELECTRICS #12;Introduction Strontium Barium ferroelectrics Introduction Strontium Barium Niobate k-Space Spectroscopy Results Conclusions SBN ­ SrxBa1-xNb2O6

Osnabrück, Universität

294

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Barium manganese oxide (BaMnO3). 721.10010...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3 ). (a...The chemical substance identified as barium manganese oxide (BaMnO3 )...

2012-07-01

295

Optimization of the tunability of barium strontium titanate films via epitaxial stresses  

E-print Network

Optimization of the tunability of barium strontium titanate films via epitaxial stresses Z.-G. Ban The tunability of epitaxial barium strontium titanate films is analyzed theoretically using a phenomenological.1063/1.1524310 I. INTRODUCTION Thin films of barium strontium titanate (BaxSr1 xTiO3, BST have long been recognized

Alpay, S. Pamir

296

1 Barium and carbon fluxes in the Canadian Arctic Archipelago 2 Helmuth Thomas,1  

E-print Network

1 Barium and carbon fluxes in the Canadian Arctic Archipelago 2 Helmuth Thomas,1 Elizabeth Shadwick Barium (Ba) in the Amundsen Gulf, 8 southeastern Beaufort Sea, was monitored over a full year from observed at river mouths, the lowest concentrations are found in water 12 masses of Atlantic origin. Barium

Boyer, Edmond

297

Structure evolution and dielectric behavior of polystyrene-capped barium titanate nanoparticles  

E-print Network

Structure evolution and dielectric behavior of polystyrene-capped barium titanate nanoparticles H35600g Polystyrene-capped barium titanate (BaTiO3) nanoparticles with sizes of 11 nm and 27 nm were nanocrystals. 1. Introduction Barium titanate (BaTiO3), one of the most commonly used perovskite compounds

Lin, Zhiqun

298

PHYSICAL REVIEW A 88, 023403 (2013) Production of translationally cold barium monohalide ions  

E-print Network

PHYSICAL REVIEW A 88, 023403 (2013) Production of translationally cold barium monohalide ions M. V) We have produced sympathetically cooled barium monohalide ions BaX+ (X = F, Cl, Br) by reacting with these predictions. Producing BaX+ ions in this way is simple and allows for the study of different barium monohalide

Chapman, Michael

299

PHYSICAL REVIEW A 81, 052328 (2010) Hyperfine and optical barium ion qubits  

E-print Network

PHYSICAL REVIEW A 81, 052328 (2010) Hyperfine and optical barium ion qubits M. R. Dietrich,* N these profoundly quantum systems. Despite a long history in ion trapping [3­5], barium has never previously been a natural source without isotope-selective ionization [6,7]. Barium possesses a long-lived metastable state

Blinov, Boris

300

Nanoscale Patterning of Barium Titanate on Block Tu Lee,, Nan Yao, and Ilhan A. Aksay*,,  

E-print Network

Nanoscale Patterning of Barium Titanate on Block Copolymers Tu Lee,, Nan Yao, and Ilhan A. Aksay of polystyrene-polybutadiene-polystyrene (Kraton D1102) has been used to pattern barium titanate precursor on the unsaturated carbon bonds in the polybutadiene matrix with antistereochemistry. Anchoring the barium titanate

Aksay, Ilhan A.

301

Barium Ion Extraction and Identification from Laser Induced Fluorescence in Gas for the  

E-print Network

Barium Ion Extraction and Identification from Laser Induced Fluorescence in Gas for the Enriched the barium ion daughter from the double beta decay of xenon-136 using laser induced fluorescence. The technique is very complex and requires an excellent understanding of the barium ion spectroscopy and its

Wechsler, Risa H.

302

TEE BARIUM CONTENT IN THE CALCAREOUS SKELETAL MATERTALS OF SOME RECENT AND  

E-print Network

TEE BARIUM CONTENT IN THE CALCAREOUS SKELETAL MATERTALS OF SOME RECENT AND FOSSIL CORALS known mlxtures of the 'vrlo m inerals. Ion-exchange methods hrere utllized to separate barium from on ln the Ilvlng eorals varled from 5- 2 + IOS ppn, to L2.5 + 6.1+% ppr. ThtB varJ-atlon ln barium

Luther, Douglas S.

303

Phase diagrams and dielectric response of epitaxial barium strontium titanate films: A theoretical analysis  

E-print Network

Phase diagrams and dielectric response of epitaxial barium strontium titanate films: A theoretical for publication 7 March 2002 We develop phase diagrams for single-domain epitaxial barium strontium titanate films. DOI: 10.1063/1.1473675 I. INTRODUCTION Thin films of barium strontium titanate BaxSr1 xTiO3 ,(BST

Alpay, S. Pamir

304

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

Code of Federal Regulations, 2010 CFR

... 2010-10-01 2010-10-01 false Barium azide-50 percent or more water wet. 173...Other Than Class 1 and Class 7 § 173.182 Barium azide—50 percent or more water wet. Barium azide—50 percent or more water wet,...

2010-10-01

305

Compact high power barium nitrite crystal-based Raman laser at 1197 nm  

E-print Network

Compact high power barium nitrite crystal-based Raman laser at 1197 nm for photoacoustic imaging of fat Rui Li Mikhail N. Slipchenko Pu Wang Ji-Xin Cheng #12;Compact high power barium nitrite crystal such a barrier, we demonstrate the construction and use of a com- pact, barium nitrite crystal-based Raman laser

Cheng, Ji-Xin

306

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Barium manganese oxide (BaMnO3). 721.10010...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3). (a...The chemical substance identified as barium manganese oxide (BaMnO3 )...

2011-07-01

307

Discrete barite particles and barium as tracers of paleoproductivity in South Atlantic sediments  

Microsoft Academic Search

Geochemical analyses as well as X ray diffraction measurements were carried out on five sediment cores from the eastern Angola Basin and the equatorial divergence of the South Atlantic. Barite concentrations were calculated from total barium concentrations by subtracting the estimated barium background supplied by ``nonbarite'' barium carriers. Barite concentrations assessed by this geochemical method show a good correspondence to

Franz Gingele; Andreas Dahmke

1994-01-01

308

Fabrication, characterization and microwave properties of polyurethane nanocomposites reinforced with iron oxide and barium titanate  

E-print Network

with iron oxide and barium titanate nanoparticles Z. Guo a,*, S.-E. Lee a , H. Kim a , S. Park a , H.T. Hahn (PU) nanocomposites reinforced with magnetic iron oxide nanoparticles and/or dielectric barium the introduction of the dielectric barium titanate nanoparticle into Fe2O3/PU nanocomposites. The permeability

Guo, John Zhanhu

309

Optimization of High Tunability Barium Strontium Titanate Thin Films Grown by RF Magnetron  

E-print Network

Optimization of High Tunability Barium Strontium Titanate Thin Films Grown by RF Magnetron Abstract-- Barium strontium titanate is a solid solution perovskite with a field-dependent permittivity.7 MV/cm. I. INTRODUCTION In recent years there has been much interest in thin-film barium strontium

York, Robert A.

310

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

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Barium azide-50 percent or more water wet. 173...Other Than Class 1 and Class 7 § 173.182 Barium azide—50 percent or more water wet. Barium azide—50 percent or more water wet,...

2013-10-01

311

Single-crystal barium titanate thin films by ion slicing T. Izuhara,a)  

E-print Network

Single-crystal barium titanate thin films by ion slicing T. Izuhara,a) I.-L. Gheorma, and R. M, D.C. 20052 Received 19 September 2002; accepted 3 December 2002 Thin barium titanate films, 0.5­8 m.1063/1.1540727 Barium titanate, BaTiO3 BTO , is a ferroelectric crystal whose outstanding electrical and optical

Reeves, Mark E.

312

M-type barium hexaferrite synthesis and characterization for phase shifter applications  

E-print Network

M-type barium hexaferrite synthesis and characterization for phase shifter applications A. T. Wise subject to AIP license or copyright; see http://jap.aip.org/about/rights_and_permissions #12;M-type barium-type barium hexaferrite films have been grown by liquid phase epitaxy and examined by x-ray diffraction

Laughlin, David E.

313

Microwave dielectric properties of graded barium strontium titanate films M. W. Cole,1,a  

E-print Network

Microwave dielectric properties of graded barium strontium titanate films M. W. Cole,1,a C. V Received 8 April 2008; accepted 13 April 2008; published online 8 May 2008 Compositionally graded barium, delay lines, filters, and phase shifters for steerable antennas.1­3 Barium strontium titanate BaxSr1-x

Alpay, S. Pamir

314

Journal of Crystal Growth 271 (2004) 128133 Growth of strontium barium niobate  

E-print Network

Journal of Crystal Growth 271 (2004) 128­133 Growth of strontium barium niobate: the liquidus. Roth Available online 11 September 2004 Abstract The liquidus­solidus phase diagram of strontium barium, and dielectric properties, strontium barium niobate, SrxBa1�xNb2O6--hen- ceforth denoted as SBN, is one

Osnabrück, Universität

315

High tunability barium strontium titanate thin films for rf circuit applications  

E-print Network

High tunability barium strontium titanate thin films for rf circuit applications N. K. Pervez,a) P) Large variations in the permittivity of rf magnetron sputtered thin-film barium strontium titanate have/cm. © 2004 American Institute of Physics. [DOI: 10.1063/1.1818724] Barium strontium titanate (BST) is a solid

York, Robert A.

316

40 CFR 721.10010 - Barium manganese oxide (BaMnO3).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Barium manganese oxide (BaMnO3). 721.10010...Chemical Substances § 721.10010 Barium manganese oxide (BaMnO3). (a...The chemical substance identified as barium manganese oxide (BaMnO3 )...

2010-07-01

317

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

Code of Federal Regulations, 2014 CFR

... 2014-10-01 2014-10-01 false Barium azide-50 percent or more water wet. 173...Other Than Class 1 and Class 7 § 173.182 Barium azide—50 percent or more water wet. Barium azide—50 percent or more water wet,...

2014-10-01

318

Single-Crystalline Barium Titanate By Jeffrey J. Urban, Jonathan E. Spanier, Lian Ouyang,  

E-print Network

Single-Crystalline Barium Titanate Nanowires By Jeffrey J. Urban, Jonathan E. Spanier, Lian Ouyang composed of barium titanate (BaTiO3), a prototypical displacive ferroelectric material[14,15] that yields-volatile memory devices with an integration density approaching 1 terabit cm±2 . 2. Synthesis of Barium Titanate

Heller, Eric

319

21 CFR 201.304 - Tannic acid and barium enema preparations.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Tannic acid and barium enema preparations. 201...Specific Drug Products § 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...

2013-04-01

320

21 CFR 201.304 - Tannic acid and barium enema preparations.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Tannic acid and barium enema preparations. 201...Specific Drug Products § 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...

2012-04-01

321

21 CFR 201.304 - Tannic acid and barium enema preparations.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Tannic acid and barium enema preparations. 201...Specific Drug Products § 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...

2014-04-01

322

21 CFR 201.304 - Tannic acid and barium enema preparations.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Tannic acid and barium enema preparations. 201...Specific Drug Products § 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...

2010-04-01

323

21 CFR 201.304 - Tannic acid and barium enema preparations.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Tannic acid and barium enema preparations. 201...Specific Drug Products § 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...

2011-04-01

324

Heparan sulfate structure: methods to study N-sulfation and NDST action.  

PubMed

Heparan sulfate proteoglycans are important modulators of cellular processes where the negatively charged polysaccharide chains interact with target proteins. The sulfation pattern of the heparan sulfate chains will determine the proteins that will bind and the affinity of the interactions. The N-deacetylase/N-sulfotransferase (NDST) enzymes are of key importance during heparan sulfate biosynthesis when the sulfation pattern is determined. In this chapter, metabolic labeling of heparan sulfate with [(35)S]sulfate or [(3)H]glucosamine in cell cultures is described, in addition to characterization of polysaccharide chain length and degree of N-sulfation. Methods to measure NDST enzyme activity are also presented. PMID:25325954

Dagälv, Anders; Lundequist, Anders; Filipek-Górniok, Beata; Dierker, Tabea; Eriksson, Inger; Kjellén, Lena

2015-01-01

325

Reducing Phosphorus in Dairy Effluent Wastewater through Flocculation and Precipitation  

E-print Network

such as diallyl-dimethyl ammonium chloride (DADMAC) and polyacrylamide (PAM) are widely used in the treatment of wastewater. Use of 4 polymeric flocculants eliminates many of the undesirable consequences associated with use of aluminum sulfate (Rout et al... of the report as our flocculant. The flocculant was used to remove the organic particles from the effluent. Ammonium hydroxide was used to raise the pH of the effluent to facilitate precipitation of phosphates. Other bases could have been used...

Bragg, A.

2003-01-01

326

Prompt ionization in the CRIT II barium releases  

NASA Astrophysics Data System (ADS)

Observations of electron and ion distributions inside a fast neutral barium jet in the ionosphere show significant fluxes within 4 km of release, presumably related to beam plasma instability processes involved in the Critical Ionization Velocity (CIV) effect. Electron fluxes exceeding 5 x 10 exp 12/sq cm-str-sec-keV were responsible for ionizing both the streaming barium and ambient oxygen. Resulting ion fluxes seem to be consistent with 1-2 percent ionization of the fast barium, as reported by optical observations, although the extended spatial distribution of the optically observed ions is difficult to reconcile with the in situ observations. When the perpendicular velocity of the neutrals falls below critical values, these processes shut off. Although these observations resemble the earlier Porcupine experimental results (Haerendel, 1982), theoretical understanding of the differences between these data and that of earlier negative experiments is still lacking.

Torbert, R. B.; Kletzing, C. A.; Liou, K.; Rau, D.

1992-05-01

327

Stability of Magnesium Sulfate Minerals in Martian Environments  

NASA Technical Reports Server (NTRS)

Viking Lander, Pathfinder, and Mars Exploration Rover missions to Mars have found abundant sulfur in surface soils and rocks, and the best indications are that magnesium sulfates are among the key hosts. At Meridiani Planum, MgSO4 salts constitute 15 to 40 wt.% of sedimentary rocks. Additional S is hosted by gypsum and jarosite. Reflectance and thermal emission spectroscopy is consistent with the presence of kieserite (MgSO4 H2O) and epsomite (MgSO4*7H2O). Theoretically, the dodecahydrate (MgSO4*12H2O) should also have precipitated. We first examine theoretically which MgSO4 minerals should have precipitated on Mars, and then how dehydration might have altered these minerals.

Marion, G. M.; Kargel, J. S.

2005-01-01

328

Chondroitin sulfate for interstitial cystitis.  

PubMed

(1) Chondroitin sulfate solution 2.0% is a glycosaminoglycan (GAG) replenishment therapy instilled into the bladder of GAG-deficient patients with interstitial cystitis (IC). (2) Two non-randomized, uncontrolled pilot studies report improvements in patient-reported symptoms after the use of chondroitin sulfate for one year. Prospective, randomized, head-to-head trials are needed to assess the effectiveness of this technology compared with other IC therapies. (3) The cost and demand for this technology are low, but there could be a significant impact on clinics that administer treatment, if uptake increases. PMID:16724430

Palylyk-Colwell, E

2006-05-01

329

Barium Levels in Soils and Centella asiatica  

PubMed Central

In this study, Centella asiatica and surface soils were collected from 12 sampling sites in Peninsular Malaysia, and the barium (Ba) concentrations were determined. The Ba concentration [?g/g dry weight (dw)] was 63.72 to 382.01 ?g/g in soils while in C. asiatica, Ba concentrations ranged from 5.05 to 21.88 ?g/g for roots, 3.31 to 11.22 ?g/g for leaves and 2.37 to 6.14 ?g/g for stems. In C. asiatica, Ba accumulation was found to be the highest in roots followed by leaves and stems. The correlation coefficients (r) of Ba between plants and soils were found to be significantly positively correlated, with the highest correlation being between roots-soils (r=0.922, p<005), followed by leaves-soils (r=0.890, p<005) and stems-soils (r=0.848, p<005). This indicates that these three parts of C. asiatica are good biomonitors of Ba pollution. For the transplantation study, four sites were selected as unpolluted [(Universiti Putra Malaysia (UPM)], semi-polluted (Seri Kembangan and Balakong) and polluted sites (Juru). Based on the transplantation study under experimental field and laboratory conditions, Ba concentrations in C. asiatica were significantly (p<0.05) higher after three weeks of exposure at Seri Kembangan, Balakong and Juru. Thus, these experimental findings confirm that the leaves, stems and roots of C. asiatica can reflect the Ba levels in the soils where this plant is found. Three weeks after back transplantation to clean soils, the Ba levels in C. asiatica were still higher than the initial Ba level even though Ba elimination occurred. In conclusion, the leaves, stems and roots of C. asiatica are good biomonitors of Ba pollution. PMID:24575242

Ong, Ghim Hock; Yap, Chee Kong; Mahmood, Maziah; Tan, Soon Guan; Hamzah, Suhaimi

2013-01-01

330

Compact pulse forming line using barium titanate ceramic material  

NASA Astrophysics Data System (ADS)

Ceramic material has very high relative permittivity, so compact pulse forming line can be made using these materials. Barium titanate (BaTiO3) has a relative permittivity of 1200 so it is used for making compact pulse forming line (PFL). Barium titanate also has piezoelectric effects so it cracks during high voltages discharges due to stresses developed in it. Barium titanate is mixed with rubber which absorbs the piezoelectric stresses when the PFL is charged and regain its original shape after the discharge. A composite mixture of barium titanate with the neoprene rubber is prepared. The relative permittivity of the composite mixture is measured to be 85. A coaxial pulse forming line of inner diameter 120 mm, outer diameter 240 mm, and length 350 mm is made and the composite mixture of barium titanate and neoprene rubber is filled between the inner and outer cylinders. The PFL is charged up to 120 kV and discharged into 5 ? load. The voltage pulse of 70 kV, 21 ns is measured across the load. The conventional PFL is made up of oil or plastics dielectrics with the relative permittivity of 2-10 [D. R. Linde, CRC Handbook of Chemistry and Physics, 90th ed. (CRC, 2009); Xia et al., Rev. Sci. Instrum. 79, 086113 (2008); Yang et al., Rev. Sci. Instrum. 81, 43303 (2010)], which increases the length of PFL. We have reported the compactness in length achieved due to increase in relative permittivity of composite mixture by adding barium titanate in neoprene rubber.

Kumar Sharma, Surender; Deb, P.; Shukla, R.; Prabaharan, T.; Shyam, A.

2011-11-01

331

Ionization and expansion of barium clouds in the ionosphere  

NASA Technical Reports Server (NTRS)

A recently envelope 3D model is used here to study the motion of the barium clouds released in the ionosphere, including the ionization stage. The ionization and the expansion of the barium clouds and the interaction between the clouds and the background ions are investigated using three simulations: a cloud without a directional velocity, a cloud with an initial velocity of 5 km/s across the B field, and a cloud with initial velocity components of 2 km/s both along and across the B field.

Ma, T.-Z.; Schunk, R. W.

1993-01-01

332

Photoionization and Photoelectric Loading of Barium Ion Traps  

E-print Network

Simple and effective techniques for loading barium ions into linear Paul traps are demonstrated. Two-step photoionization of neutral barium is achieved using a weak intercombination line (6s2 1S0 6s6p 3P1, 791 nm) followed by excitation above the ionization threshold using a nitrogen gas laser (337 nm). Isotopic selectivity is achieved by using a near Doppler-free geometry for excitation of the triplet 6s6p 3P1 state. Additionally, we report a particularly simple and efficient trap loading technique that employs an in-expensive UV epoxy curing lamp to generate photoelectrons.

A. V. Steele; L. R. Churchill; P. F. Griffin; M. S. Chapman

2007-03-22

333

[Mutagen activity of barium chloride in Salmonella typhimurium].  

PubMed

Barium chloride, which is an important industrial chemical used in pigments, lacquers, dyes, glass and pesticide production, leather tanning and cloth dying, was tested on Salmonella typhimurium (TA 1535, TA 1537, TA 1538, TA 97, TA 98, TA 100) with the reverse mutation test, with and without metabolic activation, to assess its possible genotoxic effects and any possible action with respect to standard mutagens (sodium azide, 9-aminoacridine, 2-nitrofluorene, mitomycine-C, 2 aminoacridine). Using the platelet incorporation technique, barium chloride at various progressive concentrations gave negative results under the experimental conditions of the study. PMID:2199807

Monaco, M; Dominici, R; Barisano, P; Di Palermo, G

1990-01-01

334

Growth and characterization of barium ferrite films grown using PECVD  

NASA Astrophysics Data System (ADS)

Deposition of c-axis perpendicularly oriented barium ferrite (BaFe12O19) films was attempted by means of plasma enhanced chemical vapor deposition (PECVD). A substituted acetylacetonate barium complex has been used with ferrocene in a PECVD system to deposit films of BaFe12O19. These films were examined for crystallinity, composition and magnetic properties. The crystallinity was measured by x-ray diffraction (XRD), the composition was found using scanning electron microscopy (SEM) and energy dispersive analysis of x-rays (EDAX) and the magnetic properties using vibrating sample magnetometry (VSM).

Padmanabhan, Radhakrishnan; Marji, Ehab; Kranov, Yanko; Zhang, Daqing; McIlroy, David N.

2004-05-01

335

Participation of the Pennsylvania State University in the MAP3S precipitation chemistry network. Final report  

SciTech Connect

Precipitation in central Pennsylvania was collected for more than 14 years on behalf of the Multistate Atmospheric Power Production Pollution Study (MAP3S). The MAP3S protocol, based on the sampling of precipitation from individual meteorological events over a long period of time, has allowed both for the development of a chemical climatology of precipitation in the eastern region of the United States and for a vastly improved understanding of the atmospheric processes responsible for wet acidic deposition. The precipitation chemistry data from the Penn State MAP3S site provide evidence of links to the anthropogenic emissions of sulfur dioxide and oxidant precursors. There is now little doubt that the free acidity in the precipitation of the region is due to the presence of unneutralized sulfate in the aqueous phase. In the absence of significant sources of this sulfur species and in view of supplemental enrichment studies, it is concluded that the sulfate enters cloud and rain water primarily through the aqueous-phase oxidation of sulfur dioxide emitted into the air within the geographical region of deposition. Within the source region the local abundances of sulfur dioxide often exceed those of the oxidants, so the depositions of sulfate and free acidity tend to be modulated by the availability of the strong oxidants. As a consequence, the deposition of sulfate exhibits a very strong seasonal dependence and little response to changes in the emissions of sulfur dioxide.

Lamb, D.; de Pena, R.G.

1992-04-01

336

Participation of the Pennsylvania State University in the MAP3S precipitation chemistry network  

SciTech Connect

Precipitation in central Pennsylvania was collected for more than 14 years on behalf of the Multistate Atmospheric Power Production Pollution Study (MAP3S). The MAP3S protocol, based on the sampling of precipitation from individual meteorological events over a long period of time, has allowed both for the development of a chemical climatology of precipitation in the eastern region of the United States and for a vastly improved understanding of the atmospheric processes responsible for wet acidic deposition. The precipitation chemistry data from the Penn State MAP3S site provide evidence of links to the anthropogenic emissions of sulfur dioxide and oxidant precursors. There is now little doubt that the free acidity in the precipitation of the region is due to the presence of unneutralized sulfate in the aqueous phase. In the absence of significant sources of this sulfur species and in view of supplemental enrichment studies, it is concluded that the sulfate enters cloud and rain water primarily through the aqueous-phase oxidation of sulfur dioxide emitted into the air within the geographical region of deposition. Within the source region the local abundances of sulfur dioxide often exceed those of the oxidants, so the depositions of sulfate and free acidity tend to be modulated by the availability of the strong oxidants. As a consequence, the deposition of sulfate exhibits a very strong seasonal dependence and little response to changes in the emissions of sulfur dioxide.

Lamb, D.; de Pena, R.G.

1992-04-01

337

Ferroelastic domains in lead-free barium zirconate titanate - barium calcium titanate piezoceramics  

NASA Astrophysics Data System (ADS)

Piezoelectricity was first discovered by Pierre and Jaque Curie in the year 1880. Nowadays, piezoelectric materials are used in many application such as high voltage generation in gas igniters, actuation in micro-positioning devices, generation and detection of acoustic waves, emitters and receivers for sonar technology, ultrasonic cleaning, ultrasound medical therapy, and micropumps for ink-jet printers. The most commonly used piezoelectric material since the 1950's is the solid solution system lead zirconate titanate (PZT) that offers high piezoelectric performance under a large range of operating conditions. However, the toxicity of lead requires the replacement of PZT. The studied lead-free alternatives are commonly based on potassium sodium niobate (KNN) and bismuth sodium titanate (BNT), and more recently zirconium and calcium substituted barium titanate (BZT-BCT). The BZT-BCT system exhibits large piezoelectric coefficients that can exceed even those of most PZT compositions under certain conditions. Piezoelectricity was first discovered by Pierre and Jaque Curie in the year 1880. Nowadays, piezoelectric materials are used in many application such as high voltage generation in gas igniters, actuation in micro-positioning devices, generation and detection of acoustic waves, emitters and receivers for sonar technology, ultrasonic cleaning, ultrasound medical therapy, and micropumps for ink-jet printers. The most commonly used piezoelectric material since the 1950's is the solid solution system lead zirconate titanate (PZT) that offers high piezoelectric performance under a large range of operating conditions. However, the toxicity of lead requires the replacement of PZT. The studied lead-free alternatives are commonly based on potassium sodium niobate (KNN) and bismuth sodium titanate (BNT), and more recently zirconium and calcium substituted barium titanate (BZT-BCT). The BZT-BCT system exhibits large piezoelectric coefficients that can exceed even those of most PZT compositions under certain conditions.

Ehmke, Matthias Claudius

338

Sulfate-reducing prokaryotes in river floodplains.  

E-print Network

??This thesis constitutes a pioneer attempt at elucidating the ecology of sulfate-reducing prokaryotes in river floodplains. These are non-typical sulfate-reducing environmental settings, given the generally… (more)

Miletto, M.

2007-01-01

339

21 CFR 582.5230 - Calcium sulfate.  

Code of Federal Regulations, 2013 CFR

... ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use....

2013-04-01

340

21 CFR 582.5443 - Magnesium sulfate.  

Code of Federal Regulations, 2011 CFR

... ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use....

2011-04-01

341

21 CFR 582.5443 - Magnesium sulfate.  

Code of Federal Regulations, 2013 CFR

... ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5443 Magnesium sulfate. (a) Product. Magnesium sulfate. (b) Conditions of use....

2013-04-01

342

21 CFR 582.5230 - Calcium sulfate.  

Code of Federal Regulations, 2012 CFR

... ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use....

2012-04-01

343

21 CFR 582.5461 - Manganese sulfate.  

Code of Federal Regulations, 2010 CFR

... ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5461 Manganese sulfate. (a) Product. Manganese sulfate. (b) Conditions of use....

2010-04-01

344

21 CFR 582.5461 - Manganese sulfate.  

Code of Federal Regulations, 2014 CFR

... ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5461 Manganese sulfate. (a) Product. Manganese sulfate. (b) Conditions of use....

2014-04-01

345

21 CFR 582.5997 - Zinc sulfate.  

Code of Federal Regulations, 2010 CFR

... ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or Dietary Supplements 1 § 582.5997 Zinc sulfate. (a) Product. Zinc sulfate. (b) Conditions of use. This...

2010-04-01

346

Lead removal and toxicity reduction from industrial wastewater through biological sulfate reduction process.  

PubMed

The practicability of lead removal from sulfate-rich wastewater through biological sulfate reduction process with hydrogen as electron donor was investigated. Sulfide, which was converted from sulfate by a sulfate-reducing bacteria (SRB) in a gas-lift reactor, was used to remove lead as lead sulfide precipitate. Furthermore, the toxicity of wastewater in terms of whole effluent toxicity (WET) before and after treatment was analyzed by using Microtox analyzer. The experiment was divided into three stages as follows: Stage I, startup and operation of sulfidogenic process fed with synthetic wastewater in a gas-lift reactor; Stage II, operation of sulfidogenic process fed with real wastewater in the same reactor and analysis of toxicity; and Stage III, separation of lead from wastewater. In stage I, the volumetric sulfate-sulfur loading rate was gradually increased from 1.0 g/L.d until no improvement of sulfide-sulfur production efficiency was evident at 2.58 g/L.d and maximum sulfide-sulfur concentration was set to 340 mg/L. In stage II, the results showed that the laboratory scale reactor could treat a real wastewater without inhibition or any remarkable problem. The produced sulfide-sulfur, 200 mg/L, was a little less in comparison with that of the previous stage. It could be due to the higher concentration of total dissolved solid (TDS). However, the sulfate concentration was still reduced by approximately 30%. The WET test by Microtox showed that toxicity was reduced more than 13 times. In stage III, the effluent from the reactor containing sulfide-sulfur of about 200 mg/L and lead-containing solution of 20 mg/L were fed with sulfide to lead ratio 3 moles: 1 mole into the precipitation chamber in which the optimum pH for lead sulfide precipitation of 8.0 was maintained. It was found that lead removal of 99% was attained. PMID:18780220

Teekayuttasakul, Paphungkorn; Annachhatre, Ajit P

2008-10-01

347

DYNAMICS OF AUTOMOTIVE SULFATE EMISSIONS  

EPA Science Inventory

A preliminary assessment of the potential environmental impact of automotive sulfuric acid (or sulfate) aerosol has been made by analyzing the aerosol dynamics. This analysis leads to the prediction of ambient automotive sulfuric acid aerosol concentrations over and around a larg...

348

Chemisorption And Precipitation Reactions  

EPA Science Inventory

The transport and bioavailability of chemical components within soils is, in part, controlled by partitioning between solids and solution. General terms used to describe these partitioning reactions include chemisorption and precipitation. Chemisorption is inclusive of the suit...

349

Precipitation Estimates for Hydroelectricity  

NASA Technical Reports Server (NTRS)

Hydroelectric plants require precise and timely estimates of rain, snow and other hydrometeors for operations. However, it is far from being a trivial task to measure and predict precipitation. This paper presents the linkages between precipitation science and hydroelectricity, and in doing so it provides insight into current research directions that are relevant for this renewable energy. Methods described include radars, disdrometers, satellites and numerical models. Two recent advances that have the potential of being highly beneficial for hydropower operations are featured: the Global Precipitation Measuring (GPM) mission, which represents an important leap forward in precipitation observations from space, and high performance computing (HPC) and grid technology, that allows building ensembles of numerical weather and climate models.

Tapiador, Francisco J.; Hou, Arthur Y.; de Castro, Manuel; Checa, Ramiro; Cuartero, Fernando; Barros, Ana P.

2011-01-01

350

Sulfate migration in a river affected by acid mine drainage from the Dabaoshan mining area, South China.  

PubMed

Sulfate, a major component of acid mine drainage (AMD), its migration in an AMD-affected river which located at the Dabaoshan mine area of South China was investigated to pursue the remediation strategy. The existing factors of relatively low pH values of 2.8-3.9, high concentrations of SO4(2-) (?1940mgL(-1)) and Fe(3+) (?112mgL(-1)) facilitated the precipitation of schwertmannite (Fe8O8(OH)6SO4·nH2O) in the upstream river. Geochemical model calculations implied the river waters were supersaturated, creating the potential for precipitation of iron oxyhydroxides. These minerals evolved from schwertmannite to goethite with the increasing pH from 2.8 to 5.8 along the river. The concentration of heavy metals in river waters was great reduced as a result of precipitation effects. The large size of the exchangeable sulfate pool suggested that the sediments had a strong capacity to bind SO4(2-). The XRD results indicated that schwertmannite was the predominant form of sulfate-bearing mineral phases, which was likely to act as a major sulfate sink by incorporating water-borne sulfate into its internal structure and adsorbing it onto its surface. The small size of reduced sulfur pools and strong oxidative status in the surface sediments further showed that SO4(2-) shifting from water to sediment in form of sulfate reduction was not activated. In short, precipitation of sulfate-rich iron oxyhydroxides and subsequent SO4(2-) adsorption on these minerals as well as water dilution contributed to the attenuation of SO4(2-) along the river waters. PMID:25189685

Chen, Meiqin; Lu, Guining; Guo, Chuling; Yang, Chengfang; Wu, Jingxiong; Huang, Weilin; Yee, Nathan; Dang, Zhi

2015-01-01

351

A novel approach for synthesis of M-type hexaferrites nanopowders via the co-precipitation method  

Microsoft Academic Search

M-type hexaferrites; barium hexaferrite BaFe12O19 and strontium hexaferrite SrFe12O19 powders have been successfully prepared via the co-precipitation method using 5 M sodium carbonate solution as alkali. Effects\\u000a of the molar ratio and the annealing temperature on the crystal structure, crystallite size, microstructure and the magnetic\\u000a properties of the produced powders were systematically studied. The results indicated that a single phase of

M. M. Rashad; I. A. Ibrahim

352

Fabrication of yttrium aluminum garnet transparent ceramics from yttria nanopowders synthesized by carbonate precipitation  

Microsoft Academic Search

Nanocrystalline yttria powders have been successfully synthesized by using yttrium nitrate as starting salt and ammonium hydrogen\\u000a carbonate as precipitant. It was found that a small amount of ammonia sulfate in the yttrium nitrate solution can effectively\\u000a reduce the agglomeration and the resultant powders display good dispersion. Pure cubic phase yttria powders were prepared\\u000a by calcining the precipitate at 1100 °C

Hua Gong; Dingyuan Tang; Hui Huang; Jan Ma

2009-01-01

353

Conversion of alkali metal sulfate to the carbonate  

DOEpatents

A process for converting potassium sulfate to potassium carbonate in which a mixture of potassium sulfate and calcium oxide are reacted at a temperature in the range of between about 700.degree. C. and about 800.degree. C. with a gaseous mixture having a minor amount of hydrogen and/or carbon monoxide in a diluent with the calcium oxide being present in an amount not greater than about 20 percent by weight of the potassium sulfate to produce an aqueous mixture of potassium sulfide, potassium bisulfide, potassium hydroxide and calcium sulfide and a gaseous mixture of steam and hydrogen sulfide. The potassium and calcium salts are quenched to produce an aqueous slurry of soluble potassium salts and insoluble calcium salts and a gaseous mixture of steam and hydrogen sulfide. The insoluble calcium salts are then separated from the aqueous solution of soluble potassium salts. The calcium salts are dried to produce calcium sulfide, calcium bisulfide and steam, and then, the calcium sulfide and calcium bisulfide are converted to the oxide and recycled. The soluble potassium salts are carbonated to produce potassium carbonate which is concentrated and the precipitated crystals separated. The sulfur-containing compounds are further treated.

Sheth, Atul C. (Woodridge, IL)

1982-01-01

354

Extensions to the spectrum of singly ionized barium /Ba II/  

NASA Technical Reports Server (NTRS)

The spectrum of singly ionized barium has been studied in absorption by flash pyrolysis. Corrected wavelengths and energy levels have been obtained. Fifteen new levels have been established and 24 new lines have been observed. Photoionization is shown to be the dominant ionization mechanism in this technique.

Roig, R. A.; Tondello, G.

1975-01-01

355

Dynamics of a barium release in the magnetospheric tail  

NASA Technical Reports Server (NTRS)

The late time behavior of the May 13, 1985 magnetotail barium cloud is examined. The bulk dynamics of the cloud are studied based on triangulated data and data from Fabry-Perot Doppler velocity measurements. The changes in cloud morphology in relation to the in situ measurements made by the Ion Release Module satellite are discussed.

Mende, S. B.; Swenson, G. R.; Geller, S. P.; Doolittle, J. H.; Haerendel, G.

1989-01-01

356

HEALTH EFFECTS OF HUMAN EXPOSURE TO BARIUM IN DRINKING WATER  

EPA Science Inventory

The overall objective of this study was to examine by epidemiologic and supportive laboratory studies, the human health effects associated with ingestion of barium in drinking water exceeding the U.S. drinking water standard of 1.0 mg/l. The incidence of cardiovascular mortality ...

357

PROPOSED ORAL REFERENCE DOSE (RFD) FOR BARIUM AND COMPOUNDS  

EPA Science Inventory

The Integrated Risk Information System (IRIS) is a database of EPA's consensus opinion of the human health effects that may result from exposure to various substances found in the environment. A Toxicological Review and IRIS Summary were prepared for barium and compounds in 1998 ...

358

Giant coercivity of dense nanostructured spark plasma sintered barium hexaferrite  

E-print Network

of easy axes. Several authors have succeed to produce BaFe12O19 nanoparti- cles by soft chemical route step7,8 . II. EXPERIMENTAL DETAILS Barium hexaferrite powders have been prepared by a sol-gel citrate and dense material together. In this paper, it is shown that the spark plasma sintering method (SPS) is able

359

BARIUM AND RADIUM IN WATER TREATMENT PLANT WASTES  

EPA Science Inventory

Water treatment plants at nine locations (10 plants) in Illinois and Iowa were studied to determine the characteristics and disposal practices for the sludge, brine, and backwash water containing radium (Ra) and/or barium (Ba). The treatment processes in these ten plants include ...

360

Ferroelectricity, Domain Structure, and Phase Transitions of Barium Titanate  

Microsoft Academic Search

A summarizing account is given of the research on barium titanate in progress at the Laboratory for Insulation Research at M. I. T. since 1943. The investigations have led to an understanding of the mechanism of ferroelectricity in the titanates and to discoveries such as the piezoelectric effect in the ceramics and the domain structure of the single crystals of

A. von Hippel

1950-01-01

361

REMOVING BARIUM AND RADIUM THROUGH CALCIUM CATION EXCHANGE  

EPA Science Inventory

The removal of barium (Ba) and radium (Ra), which are found in many groundwater sources, was achieved in laboratory studies with an ion exchange process. In the studies, a strong acid resin in the calcium form effectively removed Ba(+2) and Ra (+2) to meet standards. The resin wa...

362

Antarctic polar stratospheric aerosols: The roles of nitrates, chlorides and sulfates  

NASA Technical Reports Server (NTRS)

Nitric and hydrochloric acids have been postulated to condense in the winter polar stratosphere to become an important component of polar stratospheric clouds. One implication is that the removal of NO(y) from the gas phase by this mechanism allows high Cl(x) concentrations to react with O3, because the formation of ClNO3 is inhibited. Contributions of NO3 and Cl to the stratospheric aerosol were determined during the 1987 Airborne Antarctic Ozone Experiment by testing for the presence of nitrates and chlorides in the condensed phase. Aerosol particles were collected on four 500 micron diameter gold wires, each pretreated differently to give results that were specific to certain physical and chemical aerosol properties. One wire was carbon-coated for concentration and size analyses by scanning electron microscopy; X-ray energy dispersive analyses permitted the detection of S and Cl in individual particles. Three more wires were coated with Nitron, barium chloride and silver nitrate, respectively, to detect nitrate, sulfate and chloride in aerosol particles. All three ions, viz., sulfates, nitrates and chlorides were detected in the Antarctic stratospheric aerosol. In terms of number concentrations, the aerosol was dominated by sulfates, followed by chlorides and nitrates. An inverse linear regression can be established between nitrate concentrations and ozone mixing ratio, and between temperature and nitrates.

Pueschel, R. F.; Snetsinger, K. G.; Goodman, J. K.; Ferry, G. V.; Oberbeck, V. R.; Verma, S.; Fong, W.

1988-01-01

363

Preliminary study of the CRRES magnetospheric barium releases  

NASA Technical Reports Server (NTRS)

Preliminary theoretical and computational analyses of the Combined Release and Radiation Effects Satellite (CRRES) magnetospheric barium releases are presented. The focus of the studies is on the evolution of the diamagnetic cavity which is formed by the barium ions as they expand outward, and on the structuring of the density and magnetic field during the expansion phase of the releases. Two sets of simulation studies are discussed. The first set is based upon a 2D ideal MHD code and provides estimates of the time and length scales associated with the formation and collapse of the diamagnetic cavity. The second set uses a nonideal MHD code; specifically, the Hall term is included. This additional term is critical to the dynamics of sub-Alfvenic plasma expansions, such as the CRRES barium releases, because it leads to instability of the expanding plasma. Detailed simulations of the G4 and G10 releases were performed. In both cases the expanding plasma rapidly structured: the G4 release structured at time t less than about 3 s and developed scale sizes of about 1-2 km, while the G10 release structured at time t less than about 22 s and developed scale sizes of about 10-15 km. It is also found that the diamagnetic cavity size is reduced from those obtained from the ideal MHD results because of the structure. On the other hand, the structuring allows the formation of plasma blobs which appear to free stream across the magnetic field; thus, the barium plasma can propagate to larger distances traverse to the magnetic field than the case where no structuring occurs. Finally, a new normal mode of the system was discovered which may be excited at the leading edge of the expanding barium plasma.

Huba, J. D.; Bernhardt, P. A.; Lyon, J. G.

1992-01-01

364

Sulfated Polysaccharides Purified from Two Species of Padina Improve Collagen and Epidermis Formation in the Rat  

PubMed Central

Sulfated polysaccharides have shown promising effects on wound healing processes along with many other biological activities. The sulfated polysaccharides extracted from two algae species habitats in Persian Gulf were studied in vivo for their effects on collagen formation and epidermal regeneration. The polysaccharides were purified from aqueous extracts of P. tetrastromatica and P. boergesenii using CaCl2 and ethanol precipitation. The sulfate content of each polysaccharide was determined. Two identical wounds (either burn or excision) were made on the back of 4 groups of male Wistar rats (10 rats per group) under anesthesia. The algal polysaccharide ointments (2%) were applied twice daily on one side and the other wound was treated with Eucerin (as control). The rats were sacrificed on day 7 or 14, and then the wound samples were examined for epidermal thickness by light microscope. Furthermore, hydroxyproline content (as a marker of collagen formation) was spectro-photometrically measured. The polysaccharides purified from P. boergesenii had higher sulfate content (32.6±1%) compared to P. tetrastromatica (19±1%). Both algal polysaccharides showed some improvements in collagen formation (hydroxyproline content) and epidermal thickness in both wound models compared to the vehicle. The sulfated polysaccharides purified from P. tetrastromatica and P. boergesenii seaweeds are able to induce collagen formation and epidermal regeneration in the two wound models. The superior healing properties of P. boergesenii polysaccharides might be correlated to its higher sulfate content. Both algal polysaccharides are good candidates for wound healing clinical trials. PMID:24551807

Kordjazi, Moazameh; Shabanpour, Bahareh; Zabihi, Ebrahim; Faramarzi, Mohammad Ali; Feizi, Farideh; Ahmadi Gavlighi, Hassan; Feghhi, Mohammad Amin; Hosseini, Seyed Abbas

2013-01-01

365

Mine wastewater treatment using Phalaris arundinacea plant material hydrolyzate as substrate for sulfate-reducing bioreactor.  

PubMed

A low-cost substrate, Phalaris arundinacea was acid hydrolyzed (Reed Canary Grass hydrolyzate, RCGH) and used to support sulfate reduction. The experiments included batch bottle assays (35 degrees C) and a fluidized-bed bioreactor (FBR) experiment (35 degrees C) treating synthetic mine wastewater. Dry plant material was also tested as substrate in batch bottle assays. The batch assays showed sulfate reduction with the studied substrates, producing 540 and 350mgL(-1) dissolved sulfide with RCGH and dry plant material, respectively. The soluble sugars of the RCGH presumably fermented into volatile fatty acids and hydrogen, which served as electron donors for sulfate reducing bacteria. A sulfate reduction rate of 2.2-3.3gL(-1)d(-1) was obtained in the FBR experiment. The acidic influent was neutralized and the highest metal precipitation rates were 0.84g FeL(-1)d(-1) and 15mg ZnL(-1)d(-1). The sulfate reduction rate in the FBR was limited by the acetate oxidation rate of the sulfate-reducing bacteria. PMID:20137922

Lakaniemi, Aino-Maija; Nevatalo, Laura M; Kaksonen, Anna H; Puhakka, Jaakko A

2010-06-01

366

Changing hafnium speciation in aqueous sulfate solutions: a high-energy X-ray scattering study.  

PubMed

The relationship of solution speciation and the structures of corresponding precipitates is examined for an aqueous Hf(4+) sulfate series. High-energy X-ray scattering (HEXS) and Raman spectroscopy data are used to probe atomic correlations in solutions. Hf(4+) in acidic perchlorate solution shows no evidence of a mononuclear metal species but instead has a peak in the pair-distribution function (PDF), generated from the HEXS data, at 3.55 Å, indicating Hf(4+)-Hf(4+) solution correlations. The peak intensity is consistent with clusters that are, on average, larger than the tetramic unit [M4(OH)8(H2O)16](8+) usually attributed to Zr(4+) and Hf(4+) solution speciation under these conditions. Addition of sulfate results in a breakup of hydroxo-bridged oligomers into sulfate-capped dimers and, for higher concentrations, Hf-sulfate monomers. The bidentate coordination mode of sulfate dominates the dissolved precursors, although it is not found in the structure of the final crystallized product, which instead is comprised of bridging-bidentate sulfate ligation. Neither the PDF patterns nor the Raman spectra show any evidence of the larger oligomers, such as the octadecameric metal clusters, found in similar Zr(4+) solutions. The oligomeric units found in solution provide insights into possible assembly routes for crystallization. In addition to expanding our understanding of synthesis science this study also reveals differences in the aqueous chemistries between Hf and Zr, two elements with ostensibly very similar chemical behavior. PMID:24871556

Kalaji, Ali; Skanthakumar, S; Kanatzidis, Mercouri G; Mitchell, John F; Soderholm, L

2014-06-16

367

Tubular precipitation and redox gradients on a bubbling template  

PubMed Central

Tubular structures created by precipitation abound in nature, from chimneys at hydrothermal vents to soda straws in caves. Their formation is controlled by chemical gradients within which precipitation occurs, defining a surface that templates the growing structure. We report a self-organized periodic templating mechanism producing tubular structures electrochemically in iron-ammonium-sulfate solutions; iron oxides precipitate on the surface of bubbles that linger at the tube rim and then detach, leaving behind a ring of material. The acid–base and redox gradients spontaneously generated by diffusion of ammonia from the bubble into solution organize radial compositional layering within the tube wall, a mechanism studied on a larger scale by complex Liesegang patterns of iron oxides formed as ammonia diffuses through a gel containing FeSO4. When magnetite forms within the wall, a tube may grow curved in an external magnetic field. Connections with free-boundary problems in speleothem formation are emphasized. PMID:15284444

Stone, David A.; Goldstein, Raymond E.

2004-01-01

368

A simple and sensitive cAMP phosphodiesterase assay using a modification of the Ba(OH)2-ZnSO4 precipitation method.  

PubMed

A modification of the zinc-barium precipitation method is described for the measurement of phosphodiesterase activity. This method differs from the previous precipitation method in that it measures the appearance of the 5'-AMP product in the precipitate rather than the disappearance of the cAMP substrate from the supernatant. The method is simple, rapid, accurate and possesses a high sensitivity. It can be used to measure both the calmodulin activatable and nonactivatable forms of the enzyme. The procedure can be applied to monitoring phosphodiesterase activity throughout the purification of the enzyme from various tissues. PMID:6317374

LeDonne, N C; Crimaldi, A A; Coffee, C J

1983-01-01

369

Effect of topography on sulfate redistribution in Cumulonimbus cloud development.  

PubMed

An aqueous chemical module is created and included into a complex three-dimensional atmospheric cloud-resolving mesoscale model. In the chemical module, oxidation of S(IV) by ozone and hydrogen peroxide in cloud-water and rainwater, as important process of the sulfate production is included. To examine the impact of topography on the sulfate redistribution in a clean and a polluted environment, the complex topography of Serbia is included in the model. Numerical simulations of an isolated summer Cumulonimbus cloud shows that thunderstorms generate very strong vertical sulfate redistribution from the planetary boundary layer to the upper troposphere. This redistribution is sensitive to cloud dynamics, while cloud microphysics and precipitation determine wet removal of the chemical species. In simulations with realistic topography, the chemical species are transported over larger distances close to the surface, while in the upper atmosphere, there is no difference compared to the simulations without topography. The sensitivity tests of cloud chemistry to the physical processes are made. Omission of nucleation and impact scavenging of aerosols in the model simulations shows that 75.8 and 62.5 % of total sulfur mass deposited in the base experiment for the clean and the polluted environment, respectively, is the result of other processes. Exclusion of oxidation accounted for 19.2 and 37.7 % of total sulfur deposited for clean and polluted environment. Ignoring the ice phase almost not change mass of deposited sulfur: there is an increase of 2.9 and 1.5 % for clean and polluted atmosphere, respectively. Real topography conditions affect the sulfate redistribution in the sense of greater possibilities of transport. Numerical simulations without real topography give an artificial increase of deposited sulfur mass of about 25-30 %. PMID:24243093

Vujovi?, Dragana; Vu?kovi?, Vladan; Curi?, Mla?en

2014-03-01

370

Sulfate ingress in Portland cement  

SciTech Connect

The interaction of mortar with sulfate solutions leads to a reaction front within the porous material and to expansion. Thermodynamic modelling coupled with transport codes was used to predict sulfate ingress. Alternatively, 'pure' thermodynamic models - without consideration of transport - were used as a fast alternative to coupled models: they are more flexible and allow easy parameter variations but the results relate neither to distance nor to time. Both transport and pure thermodynamic modelling gave comparable results and were able to reproduce the changes observed in experiments. The calculated total volume of the solids did not exceed the initial volume of the paste indicating that not the overall volume restriction leads to the observed expansion but rather the formation of ettringite within the matrix and the development of crystallisation pressure in small pores. The calculations indicate that periodic changing of the Na{sub 2}SO{sub 4} solution results in more intense degradation.

Lothenbach, Barbara, E-mail: barbara.lothenbach@empa.c [Empa, Laboratory for Concrete and Construction Chemistry, Uberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Bary, Benoit; Le Bescop, Patrick [CEA, DEN, DPC, SCCME, Laboratory of Study of Concrete and Clay Behaviour, CEA Saclay, Batiment 158, 91191 Gif/Yvette Cedex (France); Schmidt, Thomas [Empa, Laboratory for Concrete and Construction Chemistry, Uberlandstrasse 129, CH-8600 Duebendorf (Switzerland); Leterrier, Nikos [CEA, DEN, DM2S, SFME, Laboratory of Simulation of Flows and Transport, CEA Saclay, Batiment 454, 91191 Gif/Yvette Cedex (France)

2010-08-15

371

Method for magnesium sulfate recovery  

DOEpatents

A method is described for obtaining magnesium sulfate substantially free from radioactive uranium from a slag containing the same and having a radioactivity level of at least about 7,000 pCi/gm. The slag is ground to a particle size of about 200 microns or less. The ground slag is then contacted with a concentrated sulfuric acid under certain prescribed conditions to produce a liquid product and a solid product. The particulate solid product and a minor amount of the liquid is then treated to produce a solid residue consisting essentially of magnesium sulfate substantially free of uranium and having a residual radioactivity level of less than 1,000 pCi/gm. In accordance with the preferred embodiment of the invention, a catalyst and an oxidizing agent are used during the initial acid treatment and a final solid residue has a radioactivity level of less than about 50 pCi/gm.

Gay, R.L.; Grantham, L.F.

1987-08-25

372

Method for magnesium sulfate recovery  

DOEpatents

A method of obtaining magnesium sulfate substantially free from radioactive uranium from a slag containing the same and having a radioactivity level of at least about 7000 pCi/gm. The slag is ground to a particle size of about 200 microns or less. The ground slag is then contacted with a concentrated sulfuric acid under certain prescribed conditions to produce a liquid product and a solid product. The particulate solid product and a minor amount of the liquid is then treated to produce a solid residue consisting essentially of magnesium sulfate substantially free of uranium and having a residual radioactivity level of less than 1000 pCi/gm. In accordance with the preferred embodiment of the invention, a catalyst and an oxidizing agent are used during the initial acid treatment and a final solid residue has a radioactivity level of less than about 50 pCi/gm.

Gay, Richard L. (Canoga Park, CA); Grantham, LeRoy F. (Calabasas, CA)

1987-01-01

373

Distribution and variability of precipitation chemistry in the conterminous United States, January through December 1983  

USGS Publications Warehouse

Analysis of atmospheric precipitation samples, collected during the 1983 calendar year from 109 National Trends Network sites in the United States, are presented in this report. The sites were grouped into six geographical regions based on the chemical composition of the samples. Precipitation chemistry in these regions was influenced by proximity to (1) oceans, (2) major industrial and fossil-fuel consuming areas, and (3) major agricultural and livestock areas. Frequency distributions of ionic composition, determined on 10 chemical constituents and on precipitation quantities for each site, showed wide variations in chemical concentrations and precipitation quantities from site to site. Of the 109 sites, 55 had data coverage for the year sufficient to characterize precipitation quality patterns on a nationwide basis. Except for ammonium and calcium, both of which showed largest concentrations in the agricultural midwest and plains states, the largest concentrations and loads generally were in areas that include the heavily industrialized population center of the eastern United States. Except for hydrogen, all chemical ions are inversely related to the quantity of precipitation depth. Precipitation quantities generally account for less than 30% of chemical variation in precipitation samples. However, precipitation quantities account for 30 to 65% of the variations of calcium concentrations in precipitation. In regions where precipitation has a large ionic proportion of hydrogen-ion equivalents, much of the hydrogen-ion concentration could be balanced by sulfate equivalents and partly balanced by nitrite-plus-nitrate equivalents. In the regions where hydrogen-ion equivalents in precipitation were smaller, ammonion-and calcium-ion equivalents were necessary, along with the hydrogen-ion equivalents, to balance the sulfate plus nitrite-plus-nitrate equivalent. (USGS)

Rinella, J.F.; Miller, T.L.

1988-01-01

374

Crystallization of glycine-sulfate  

NASA Astrophysics Data System (ADS)

TGS and DGS crystals have been grown from the aqueous solutions and the results are reported in this paper. It has been found that the pH of the solution at the time of crystallization is the most important parameter determining the crystallization of the different glycine-sulfate compounds. It has been shown that for the crystallization of TGS the required pH is ?1.5.

Pandya, G. R.; Vyas, D. D.

1980-12-01

375

Precipitation HMM Recalls on BNT  

E-print Network

Precipitation HMM Recalls on BNT Results Exact Belief Propagation in Bayesian Networks: from to Algorithms #12;Precipitation HMM Recalls on BNT Results Outline 1 Precipitation HMM Definition Marginal to Algorithms #12;Precipitation HMM Recalls on BNT Results Definition Marginal Distributions Recursions

Nuel, Gregory

376

Extracellular iron-sulfur precipitates from growth of Desulfovibrio desulfuricans  

SciTech Connect

The authors have examined extracellular iron-bearing precipitates resulting from the growth of Desulfovibrio desulfuricans in a basal medium with lactate as the carbon source and ferrous sulfate. Black precipitates were obtained when D. desulfuricans was grown with an excess of FeSO{sub 4}. When D. desulfuricans was grown under conditions with low amounts of FeSO{sub 4}, brown precipitates were obtained. The precipitates were characterized by iron K-edge XAFS (X-ray absorption fine structure), {sup 57}Fe Moessbauer-effect spectroscopy, and powder X-ray diffraction. Both were noncrystalline and nonmagnetic (at room temperature) solids containing high-spin Fe(III). The spectroscopic data for the black precipitates indicate the formation of an iron-sulfur phase with 6 nearest S neighbors about Fe at an average distance of 2.24(1) {angstrom}, whereas the brown precipitates are an iron-oxygen-sulfur phase with 6 nearest O neighbors about Fe at an average distance of 1.95(1) {angstrom}.

Antonio, M. R.; Tischler, M. L.; Witzcak, D.

1999-12-20

377

ACID PRECIPITATION PATTERNS AND TRENDS IN EASTERN NORTH AMERICA, 1980-1984  

EPA Science Inventory

Using data compiled from seven nationwide precipitation chemistry networks in the U.S. and Canada, the spatial distribution of hydrogen, sulfate, and nitrate ions in North America is discussed. eographic patterns of concentration and deposition are characterized using isopleth ma...

378

ASSESSING MINE DRAINAGE WATER QUALITY FROM THE COLOR AND SPECTRAL REFLECTANCE OF CHEMICAL PRECIPITATES  

EPA Science Inventory

The pH and dissolved sulfate concentrations of mine impacted waters were estimated on the basis of the spectral reflectance of resident sediments composed mostly of chemical precipitates. Mine drainage sediments were collected from sites in the Anthracite Region of eastern Pe...

379

Investigation of catalysts based on activated aluminum oxide, prepared by single-pass continuous precipitation  

Microsoft Academic Search

The properties of an activated aluminum oxide obtained by continuous single-pass precipitation of the hydroxide from solutions of basic aluminum sulfate and sodium aluminate with a low alkali modulus have been studied by physicochemicalmethods; this study has shown that the crystalline and porous structure of this aluminum oxide differs considerably from that of aluminum oxide obtained by a double-pass batch

N. P. Poezd; I. Ya. Perezhigina; E. D. Radchenko; D. F. Poezd; A. V. Agafonov; A. N. Chagovets

1978-01-01

380

PAPST1 regulates sulfation of heparan sulfate proteoglycans in epithelial MDCK II cells.  

PubMed

Proteoglycan (PG) sulfation depends on activated nucleotide sulfate, 3'-phosphoadenosine-5'-phosphosulfate (PAPS). Transporters in the Golgi membrane translocate PAPS from the cytoplasm into the organelle lumen where PG sulfation occurs. Silencing of PAPS transporter (PAPST) 1 in epithelial MDCK cells reduced PAPS uptake into Golgi vesicles. Surprisingly, at the same time sulfation of heparan sulfate (HS) was stimulated. The effect was pathway specific in polarized epithelial cells. Basolaterally secreted proteoglycans (PGs) displayed an altered HS sulfation pattern and increased growth factor binding capacity. In contrast, the sulfation pattern of apically secreted PGs was unchanged while the secretion was reduced. Regulation of PAPST1 allows epithelial cells to prioritize between PG sulfation in the apical and basolateral secretory routes at the level of the Golgi apparatus. This provides sulfation patterns that ensure PG functions at the extracellular level, such as growth factor binding. PMID:25138304

Dick, Gunnar; Akslen-Hoel, Linn Kristin; Grøndahl, Frøy; Kjos, Ingrid; Maccarana, Marco; Prydz, Kristian

2015-01-01

381

Seasonal influence on sulfate reduction and zinc sequestration in subsurface treatment wetlands.  

PubMed

To characterize the effects of season, temperature, plant species, and chemical oxygen demand (COD) loading on sulfate reduction and metals removal in treatment wetlands we measured pore water redox potentials and concentrations of sulfate, sulfide, zinc and COD in subsurface wetland microcosms. Two batch incubations of 20 day duration were conducted in each of four seasons defined by temperature and daylight duration. Four treatments were compared: unplanted controls, Typha latifolia (broadleaf cattail), and Schoenoplectus acutus (hardstem bulrush), all at low COD loading (267 mg/L), plus bulrush at high COD loading (534 mg/L). Initial SO4-S and zinc concentrations were 67 and 24 mg/L, respectively. For all treatments, sulfate removal was least in winter (4 degrees C, plant dormancy) greatest in summer (24 degrees C, active plant growth) and intermediate in spring and fall (14 degrees C), but seasonal variation was greater in cattail, and especially, bulrush treatments. Redox measurements indicated that, in winter, plant-mediated oxygen transfer inhibited activity of sulfate reducing bacteria, exacerbating the reduction in sulfate removal due to temperature. Doubling the COD load in bulrush treatments increased sulfate removal by only 20-30% when averaged over all seasons and did not alter the basic pattern of seasonal variation, despite tempering the wintertime increase in redox potential. Seasonal and treatment effects on zinc removal were broadly consistent with sulfate removal and presumably reflected zinc-sulfide precipitation. Results strongly suggest that interactive effects of COD loading rate, temperature, season, and plant species control not only sulfate reduction and zinc sequestration, but also the balance of competition between various microbial consortia responsible for water treatment in constructed wetlands. PMID:17599383

Stein, Otto R; Borden-Stewart, Deborah J; Hook, Paul B; Jones, Warren L

2007-08-01

382

Redox-controlled changes in cadmium solubility and solid-phase speciation in a paddy soil as affected by reducible sulfate and copper.  

PubMed

The solubility of Cd in contaminated paddy soils controls Cd uptake by rice, which is an important food safety issue. We investigated the solution and solid-phase dynamics of Cd in a paddy soil spiked with ?20 mg kg(-1) Cd during 40 days of soil reduction followed by 28 days of soil reoxidation as a function of the amounts of sulfate available for microbial reduction and of Cu that competes with Cd for precipitation with biogenic sulfide. At an excess of sulfate over (Cd + Cu), dissolved Cd decreased during sulfate reduction and Cd was transformed into a poorly soluble phase identified as Cd-sulfide using Cd K-edge X-ray absorption spectroscopy (XAS). The extent of Cd-sulfide precipitation decreased with decreasing sulfate and increasing Cu contents, even if sulfate exceeded Cd. When both Cu and Cd exceeded sulfate, dissolved and mobilizable Cd remained elevated after 40 days of soil reduction. During soil reoxidation, Cd-sulfide was readily transformed back into more soluble species. Our data suggest that Cd-sulfide formation in flooded paddy soil may be limited when the amounts of Cd and other chalcophile metals significantly exceed reducible sulfate Therefore, in multimetal contaminated paddy soils with low sulfate contents, Cd may remain labile during soil flooding, which enhances the risk for Cd transfer into rice. PMID:24171446

Fulda, Beate; Voegelin, Andreas; Kretzschmar, Ruben

2013-11-19

383

Historical and Short-Term Controls on Sulfate Reduction and Alkalinity Generation in Three Aquatic Ecosystems of  

E-print Network

precipitation, pyrite, sediments #12;Introduction First described as acid rain in 1852 by Scottish chemist Angus.19 to 13.47 mEq m-2 y-1 in freshwater sediments. Keywords: Sulfate reduction, alkalinity, acid Smith, all forms of atmospheric acid deposition continue to be an environmental problem faced

Vallino, Joseph J.

384

Enzymes Induced in a Bacterium by Growth on Sodium Dodecyl Sulfate  

PubMed Central

Alkyl sulfatase was induced by growth on nutrient broth plus sodium dodecyl sulfate (SDS) in a bacterium we have designated Pseudomonas C12B. Measurement of the radioactivity of S35O4= released from SDS35 by the enzyme in cell-free extracts provided an effective assay technique. The barium chloranilate assay for release of SO4= from SDS was somewhat less sensitive but effective if analyzed at 332 m?. This test was only approximately 55% as sensitive if analyzed at 530 m?. The activity of the glyoxylate bypass enzymes, isocitrate lyase and malate synthetase, was significantly stimulated by growth of the bacteria on SDS as the sole carbon source, but not by growth on nutrient broth or nutrient broth plus SDS. PMID:14201090

Williams, Joy; Payne, W. J.

1964-01-01

385

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

NASA Technical Reports Server (NTRS)

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.

Forman, R.

1976-01-01

386

Design, testing, fabrication and launch support of a liquid chemical barium release payload (utilizing the liquid fluorine-barium salt/hydrazine system)  

NASA Technical Reports Server (NTRS)

A payload was designed which included a cryogenic oxidizer tank, a fuel tank, and burner section. Release of 30 lb of chemicals was planned to occur in 2 seconds at the optimum oxidizer to fuel ratio. The chemicals consisted of 17 lb of liquid fluorine oxidizer and 13 lb of hydrazine-barium salt fuel mixture. The fuel mixture was 17% barium chloride, 16% barium nitrate, and 67% hydrazine, and contained 2.6 lb of available barium. Two significant problem areas were resolved during the program: explosive valve development and burner operation. The release payload was flight tested, from Wallops Island, Virginia. The release took place at an altitude of approximately 260 km. The release produced a luminous cloud which expanded very rapidly, disappearing to the human eye in about 20 seconds. Barium ion concentration slowly increased over a wide area of sky until measurements were discontinued at sunrise (about 30 minutes).

Stokes, C. S.; Smith, E. W.; Murphy, W. J.

1972-01-01

387

Inhibition of synthesis of heparan sulfate by selenate: Possible dependence on sulfation for chain polymerization  

SciTech Connect

Selenate, a sulfation inhibitor, blocks the synthesis of heparan sulfate and chondroitin sulfate by cultured endothelial cells. In contrast, selenate does not affect the production of hyaluronic acid, a nonsulfated glycosaminoglycan. No differences in molecular weight, ({sup 3}H)glucosamine/({sup 35}S)sulfuric acid ratios, or disaccharide composition were observed when the heparan sulfate synthesized by selenate-treated cells was compared with that of control cells. The absence of undersulfated chains in preparations from cultures exposed to selenate supports the concept that, in the intact cell, the polymerization of heparan sulfate might be dependent on the sulfation of the saccharide units added to the growing glycosaminoglycan chain.

Dietrich, C.P.; Nader, H.B. (Paulist School of Medicine, Sao Paulo (Brazil)); Buonassisi, V.; Colburn, P. (W. Alton Jones Cell Science Center, Lake Placid, NY (USA))

1988-01-01

388

Linking Microbial Ecology to Geochemistry in Sulfate Reducing Systems  

NASA Astrophysics Data System (ADS)

Sulfate reducing bioreactors (SRBRs) can serve as passive treatment systems for mining influenced waters (MIW). An enhanced understanding of the biogeochemistry and efficacy of SRBRs can be achieved by combining molecular biological and geochemical techniques in both field and column settings. To this end, a spatial and temporal sequence of eight pilot-scale columns were analyzed employing a multidisciplinary approach using ICP-AES, next-generation sequencing, and SEM-EDX to explore the effects of variable substrate on community structure and performance (measured by Zn removal). All pilot scale reactors contained 30% limestone by mass, 7 of the 8 had variable amounts of woodchips, sawdust, and alfalfa hay, and an 8th column where the only carbon source was walnut shells. High throughput sequencing of DNA extracted from liquid in pilot-scale columns reveals, similarly to an analogous field system in Arizona, a dominance of Proteobacteria. However, after the first pore volume, performance differences between substrate permutations emerged, where columns containing exclusively walnut shells or sawdust exhibited a more effective startup and metal removal than did columns containing exclusively woodchips or alfalfa hay. SEM-EDX analysis revealed the initial formation of gypsum (CaSO4) precipitates regardless of substrate. Zn was observed in the presence of Ca, S, and O in some column samples, suggesting there was co-precipitation of Zn and CaSO4. This is congruent with micro-XAS analysis of field data suggesting iron sulfides were co-precipitating with gypsum. A SEM-EDX analysis from a subsequent sampling event (8 months into operation) indicated that precipitation may be shifting to ZnS and ZnCO3. Biplots employing Canonical Correspondence Analysis (CCA) describe how diversity scales with performance and substrate selection, and how community shifts may result in differential performance and precipitation in response to selective pressure of bioreactor material on community composition. CCA of Shannon diversity data after one pore volume revealed that zinc removal, walnut shell content, and abundance of delta-Proteobacteria (sulfate reducing organisms) were all corresponding elements. However, after several pore volumes, the walnut shell column was no longer removing Zn as effectively, and community shifts were observed throughout the columns. Analysis of field and laboratory scale microbiological and geochemical shifts, in parallel, gives insight into key biogeochemical variables linked to the performance of passive remediation systems used for the treatment of contaminated MIW, while also providing further insight into metal immobilization at the microbe-mineral interface.

Drennan, D. M.; Lee, I.; Landkamer, L.; Almstrand, R.; Figueroa, L. A.; Sharp, J. H.

2013-12-01

389

Barium and Yttrium abundance in intermediate-age and old open clusters  

E-print Network

Barium is a neutron capture element, that, in open clusters, is frequently over-abundant with respect to the Iron. A clear explanation for this is still missing. Additionally, its gradient across the Galactic disk is poorly constrained. We measure the abundance of yttrium and barium using the synthetic spectrum method from UVES high-resolution spectra of eight distant open clusters, namely Ruprecht 4, Ruprecht 7, Berkeley 25, Berkeley 73, Berkeley 75, NGC 6192, NGC 6404, and NGC 6583. The barium abundance was estimated using NLTE approximation. We confirm that Barium is indeed over-abundant in most clusters, especially young clusters. Finally, we investigated the trend of yttrium and barium abundances as a function of distance in the Galaxy and ages. Several scenarios for the barium over-abundance are then discussed.

Mishenina, T; Carraro, G; Kovtyukh, V V; Yegorova, I A

2013-01-01

390

Life Model of Hollow Cathodes Using a Barium Calcium Aluminate Impregnated Tungsten Emitter  

NASA Technical Reports Server (NTRS)

Hollow cathodes with barium calcium aluminate impregnated tungsten emitters for thermionic emission are widely used in electric propulsion. These high current, low power cathodes are employed in ion thrusters, Hall thrusters, and on the International Space Station in plasma contactors. The requirements on hollow cathode life are growing more stringent with the increasing use of electric propulsion technology. The life limiting mechanism that determines the entitlement lifetime of a barium impregnated thermionic emission cathode is the evolution and transport of barium away from the emitter surface. A model is being developed to study the process of barium transport and loss from the emitter insert in hollow cathodes. The model accounts for the production of barium through analysis of the relevant impregnate chemistry. Transport of barium through the approximately static gas is also being treated. Finally, the effect of temperature gradients within the cathode are considered.

Kovaleski, S. D.; Burke, Tom (Technical Monitor)

2001-01-01

391

Vanadium doped barium germanate microrods and photocatalytic properties under solar light  

NASA Astrophysics Data System (ADS)

Vanadium doped barium germanate microrods have been prepared by a facile hydrothermal process. The obtained vanadium doped barium germanate microrods are proved to be hexagonal BaGe4O9 and orthorhombic Ba2V2O7 phases by X-ray diffraction. Scanning electron microscopy shows that the vanadium doped barium germanate products consist of microrods with the diameter of microscale size. The diameter of the mirorods decreases from 800 nm to 150 nm with the vanadium doping mass percentage increasing from 1% to 10%. Solid UV-vis diffuse reflectance spectra show that the band gap of the vanadium doped barium germanate is smaller than that of the undoped barium germanate. The photocatalytic activity has been greatly enhanced by the vanadium doping. The vanadium doped barium germanate microrods exhibit great application potential for the photocatalytic degradation of methylene blue under solar light irradiation.

Pei, L. Z.; Wang, S.; Liu, H. D.; Lin, N.; Yu, H. Y.

2015-01-01

392

Magnetic Field Alignment of Barium Ferrite Thick Films for Microwave Circulator Applications  

NASA Astrophysics Data System (ADS)

Barium ferrite films were prepared using screen printing method for their applications in self-biased microwave integrated circulators. The influences of alignment magnetic field on the microstructure and magnetic properties of the barium ferrite thick films were investigated. The results show that the (00l) peaks of the barium ferrite films are enhanced with the increase of alignment magnetic field. Hexagonal BaFe12O19 platelets rotate and orient with c-axis perpendicular to the film plane after the magnetic field aligning. The remanence ratio of the barium ferrite films is improved from 0.52 to 0.78 with the increase of alignment magnetic field from 0 to 8 kOe. By magnetic field aligning, barium ferrite thick films with the remanence ratio of 0.8 have been prepared. A prototype of microwave integrated circulator is developed with the prepared barium ferrite films.

Peng, Bin; Wang, Yuanchao; Zhang, Wanli; Zhang, Wenxu; Tan, Ke

2012-10-01

393

Treatment by sulfate-reducing bacteria of Chessy acid-mine drainage and metals recovery  

Microsoft Academic Search

Acid-mine drainage can contain high concentrations of heavy metals and release of these contaminants into the environment is generally avoided by lime neutralization. However, this classical treatment is expensive and generates large amounts of residual sludge. The selective precipitation of metals using H2S produced biologically by sulfate-reducing bacteria has been proposed as an alternative process. Here, we report on experiments

S Foucher; F Battaglia-Brunet; I Ignatiadis; D Morin

2001-01-01

394

Water isotopes in precipitation  

Microsoft Academic Search

Variations of HDO and H218O concentrations are observed in precipitation both on a geographical and on a temporal basis. These variations, resulting from successive isotopic fractionation processes at each phase change of water during its atmospheric cycle, are well documented through the IAEA\\/WMO network. Isotope concentrations are, in middle and high latitudes, linearly related to the annual mean temperature at

J. Jouzel; G. Hoffmann; R. D. Koster; V. Masson

2000-01-01

395

Installing Precipitation Gage  

USGS Multimedia Gallery

During August 2013, the Beaver Creek wildfire burned more than 114,000 acres near the south-central Idaho communities of Sun Valley, Ketchum, and Hailey. Partnering with Blaine County, the USGS installed a network of real-time precipitation gages in the burn area. Real-time information from the gage...

396

Total Precipitable Water  

SciTech Connect

The simulation was performed on 64K cores of Intrepid, running at 0.25 simulated-years-per-day and taking 25 million core-hours. This is the first simulation using both the CAM5 physics and the highly scalable spectral element dynamical core. The animation of Total Precipitable Water clearly shows hurricanes developing in the Atlantic and Pacific.

None

2012-01-01

397

Testing Precipitation Gage  

USGS Multimedia Gallery

During August 2013, the Beaver Creek wildfire burned more than 114,000 acres near the south-central Idaho communities of Sun Valley, Ketchum, and Hailey. Partnering with Blaine County, the USGS installed a network of real-time precipitation gages in the burn area. Real-time information from the gage...

398

EFFECTS OF ACID PRECIPITATION  

EPA Science Inventory

Recent reviews of available data indicate that precipitation in a large region of North America is highly acidic when its pH is compared with the expected pH value of 5.65 for pure rain water in equilibrium with CO2. A growing body of evidence suggests that acid rain is responsib...

399

Wave propagation in precipitation  

NASA Astrophysics Data System (ADS)

A unified model of electromagnetic wave interaction with the precipitation medium is presented. The scattering of an incident monochromatic field by a polydispersion of particles is considered. The radiometric implications of the thermal radiation of a polydispersion are outlined. Propagation through inhomogeneous dispersions, turbulence, and scintillation is treated. Monostatic dual polarization radar remote sensing of polydispersions is covered.

Delogne, P.

1983-04-01

400

Sulfate reduction in freshwater wetland soils and the effects of sulfate and substrate loading  

SciTech Connect

Elevated sulfate and organic C loadings in freshwater wetlands could stimulate dissimilatory sulfate reduction that oxidizes organic C, produces hydrogen sulfide and alkalinity, and sequesters trace metals. The authors determined the extent of sulfate reduction in two freshwater wetland soils, that is black gum (Nyssa biflona) swamp soils and titi (Cliftonia monophylla) swamp soils, in northern Florida. They also investigated the potential of sulfate reduction in the wetland soils by adding sulfate, organic substrate, and lime. Sulfate reduction was found to be an active process in both swamp soils without any amendment, where the pore water pH was as low as 3.6 and sulfate concentration was as low as 5 mg L{sup {minus}1}. Without amendment, 11 to 14% of organic C was oxidized through sulfate reduction in the swamp soils. Sulfate loading, liming, and substrate addition significantly increased sulfate reduction in the black gum swamp soil, but none of those treatments increase sulfate reduction in the titi swamp soil. The limiting factor for sulfate reduction in the titi swamp soil were likely texture and soil aggregate related properties. The results suggested that wastewater loading may increase sulfate reduction in some freshwater wetlands such as the black swamps while it has no stimulating effect on other wetlands such as the titi swamps.

Feng, J.; Hsieh, Y.P. [Florida A and M Univ., Tallahassee, FL (United States)

1998-07-01

401

Numerical simulation of a radially injected barium cloud  

NASA Technical Reports Server (NTRS)

Electrostatic two-dimensional numerical simulations of a radially symmetric barium injection experiment demonstrate that ions created by solar UV irradiation are electrostatically bound to the electrons which remain tied to the field lines on which they are created. Two possible instabilities are identified, but neither of them causes the barium plasma cloud to polarize in a way that would permit the plasma to keep up with the neutrals. In a second model, the velocity of the neutrals is allowed to be a function of the azimuthal angle. Here, a portion of the cloud does polarize in a way that allows a portion of the plasma to detach and move outward at the approximate speed of the neutrals. No rapid detachment is found when only the density of the neutrals is given an azimuthal asymmetry.

Swift, D. W.; Wescott, E. M.

1981-01-01

402

The Skylab barium plasma injection experiments. I - Convection observations  

NASA Technical Reports Server (NTRS)

Two barium-plasma injection experiments were carried out during magnetically active periods in conjunction with the Skylab 3 mission. The high-explosive shaped charges were launched near dawn on November 27 and December 4, 1973, UT. In both cases, the AE index was near 400 gammas, and extensive pulsating auroras covered the sky. The first experiment, Skylab Alpha, occurred in the waning phase of a 1000-gamma substorm, and the second, Skylab Beta, occurred in the expansive phase of an 800-gamma substorm. In both, the convection was generally magnetically eastward, with 100-km-level electric fields near 40 mV/m. However, in the Alpha experiment the observed orientation of the barium flux tube fit theoretical field lines having no parallel current, but the Beta flux-tube orientation indicated a substantial upward parallel sheet current.

Wescott, E. M.; Stenbaek-Nielsen, H. C.; Davis, T. N.; Peek, H. M.

1976-01-01

403

Observations and theory of the AMPTE magnetotail barium releases  

NASA Technical Reports Server (NTRS)

The barium releases in the magnetotail during the Active Magnetospheric Particle Tracer Explorers (AMPTE) operation were monitored by ground-based imagers and by instruments on the Ion Release Module. After each release, the data show the formation of a structured diamagnetic cavity. The cavity grows until the dynamic pressure of the expanding ions balances the magnetic pressure on its surface. The magnetic field inside the cavity is zero. The barium ions collect on the surface of the cavity, producing a shell. Plasma irregularities form along magnetic field lines draped over the surface of the cavity. The scale size of the irregularities is nearly equal to the thickness of the shell. The evolution and structuring of the diamagnetic cavity are modeled using magnetohydrodynamics theory.

Bernhardt, P. A.; Roussel-Dupre, R. A.; Pongratz, M. B.; Haerendel, G.; Valenzuela, A.

1987-01-01

404

Structural Study of Rare Earth Oxides Doped by Barium  

NASA Astrophysics Data System (ADS)

Two series of samples noted LnBaX (where Ln = Nd or Sm, X = at. % of Ba) were dispersed in an excess of bi-distilled and demineralised water during 16 h at 80° from Ln2O3 and ?-BaCO3. These samples were calcined under air at 450 and 1150 °C then characterized by X-ray diffraction, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy. After calcination at 450 °C, XRD and XPS measurement shows the presence of Ln2O3, barium carbonates, oxy-carbonates and oxy-hydroxides LnO(OH) in LnBaX. At 1150 °C, results shows that NdBaX and SmBaX are formed by the BaO and Ln2O3. However neodymium and samarium oxides do not incorporate barium.

Ghelamallah, Madani; Kacimi, Soufi; Fertout, Radia Imane

405

Electromagnetic properties of photodefinable barium ferrite polymer composites  

NASA Astrophysics Data System (ADS)

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 ?m for coarse and 0.8-1.0 ?m 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.

Sholiyi, Olusegun; Lee, Jaejin; Williams, John D.

2014-07-01

406

Anomalies of piezoelectric coefficients in barium titanate thin films  

NASA Astrophysics Data System (ADS)

Modeling of electromechanical devices involves the use of different material coefficients, whose measurement is a difficult task, especially when the problem concerns thin films. Required coefficients of thin films could be found theoretically, using known values of the bulk constants. Electromechanical coefficients of barium titanate thin films are still unknown; therefore, it is expedient to carry out their calculations. We give here the full set of electromechanical coefficients of barium titanate thin films for the whole range of technologically available misfit strains. In the present paper, piezoelectric coefficients as functions of a misfit strain were calculated. It was revealed that piezoelectric coefficients exhibit anomalies at phase boundaries and inside the monoclinic r-phase as well. The obtained results allow finding the required values of the thin-film parameters, varying the misfit strain.

Shirokov, Vladimir; Kalinchuk, Valery; Shakhovoy, Roman; Yuzyuk, Yury

2014-11-01

407

The crystal growth of barium flouride in aqueous solution  

NASA Astrophysics Data System (ADS)

The kinetics of growth of barium flouride seed crystals were investigated in aqueous solution at 25°C using a constant composition method, in which the supersaturation and ionic strength were maintained constant by the addition of titrants consisting of barium nitrate and potassium flouride solutions. The rates of reaction, studied over a range of supersaturation (? ? 0.4 to 1.0), were interpreted in terms of crystal growth models. A spiral growth mechanism best describes the data, and scanning electron microscopy indicates a three-dimensional growth. In the presence of inorganic additives such as phosphate, however, induction periods precede a morphological two-dimensional crystallization. Coulter Counter results show little crystal agglomeration.

Barone, J. P.; Svrjcek, D.; Nancollas, G. H.

1983-06-01

408

NASA/Max Planck Institute Barium Ion Cloud Project.  

NASA Technical Reports Server (NTRS)

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.

Brence, W. A.; Carr, R. E.; Gerlach, J. C.; Neuss, H.

1973-01-01

409

Depolymerization of sulfated polysaccharides under hydrothermal conditions.  

PubMed

Fucoidan and chondroitin sulfate, which are well known sulfated polysaccharides, were depolymerized under hydrothermal conditions (120-180°C, 5-60min) as a method for the preparation of sulfated polysaccharides with controlled molecular weights. Fucoidan was easily depolymerized, and the change of the molecular weight values depended on the reaction temperature and time. The degree of sulfation and IR spectra of the depolymerized fucoidan did not change compared with those of untreated fucoidan at reaction temperatures below 140°C. However, fucoidan was partially degraded during depolymerization above 160°C. Nearly the same depolymerization was observed for chondroitin sulfate. These results indicate that hydrothermal treatment is applicable for the depolymerization of sulfated polysaccharides, and that low molecular weight products without desulfation and deformation of the initial glycan structures can be obtained under mild hydrothermal conditions. PMID:24361592

Morimoto, Minoru; Takatori, Masaki; Hayashi, Tetsuya; Mori, Daiki; Takashima, Osamu; Yoshida, Shinichi; Sato, Kimihiko; Kawamoto, Hitoshi; Tamura, Jun-ichi; Izawa, Hironori; Ifuku, Shinsuke; Saimoto, Hiroyuki

2014-01-30

410

The positive temperature coefficient of resistivity in barium titanate  

Microsoft Academic Search

Positive temperature coefficient of resistivity (PTCR) materials have become very important components, and among these materials\\u000a barium titanate compounds make up the most important group. When properly processed these compounds show a high PTCR at the\\u000a Curie temperature (the transition temperature from the ferroelectric tetragonal phase to the paraelectric cube phase). In\\u000a the first half of this paper literature related

B. Huybrechts; K. Ishizaki; M. Takata

1995-01-01

411

Synthesis and characterization of barium ferrite–silica nanocomposites  

SciTech Connect

In this work, we prepared barium ferrite-silica (BaM-SiO{sub 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{sub 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{sub 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.

Aguilar-González, M.A.; Mendoza-Suárez, G.; Padmasree, K.P., E-mail: padma512@yahoo.com

2013-10-15

412

Elastic and Piezoelectric Coefficients of Single-Crystal Barium Titanate  

Microsoft Academic Search

Mechanical resonance and antiresonance frequencies were measured on barium titanate single-crystal elements maintained under electric dc bias from -50°C to +150°C. A complete set of elastic, piezoelectric, and dielectric constants of the tetragonal modification at 25°C is obtained. The elastic compliances show substantial deviation from cubic symmetry. Measurements in the orthorhombic state show longitudinal compliance four times higher than in

Don Berlincourt; Hans Jaffe

1958-01-01

413

Texture and Microstructural Development in Gelcast Barium Hexaferrite  

SciTech Connect

The development of texture in barium hexaferrite by templated grain growth was studied as a function of the Fe2O3/BaCO3 ratio, B2O3 additions in the starting materials, and sintering temperature. A magnetic field was used to orient the template particles during the gelcasting process. Excess BaCO3 resulted in abnormal grain growth and maximized texture, while B2O3 additions promoted coarsening, but no abnormal grain growth.

Hovis, David B. [Northwestern University, Evanston; Faber, Katherine T. [Northwestern University, Evanston; Kenik, Edward A [ORNL

2008-01-01

414

Barium–borate–flyash glasses: As radiation shielding materials  

Microsoft Academic Search

The attenuation coefficients of barium–borate–flyash glasses have been measured for ?-ray photon energies of 356, 662, 1173 and 1332keV using narrow beam transmission geometry. The photon beam was highly collimated and overall scatter acceptance angle was less than 3°. Our results have an uncertainty of less than 3%. These coefficients were then used to obtain the values of mean free

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

2008-01-01

415

Barium isotopes in chondritic meteorites: implications for planetary reservoir models.  

PubMed

High-precision barium isotope measurements yielded differences of up to 25 parts per million in the 137Ba/136Ba ratio and 60 parts per million in the 138Ba/136Ba ratio between chondrites and Earth. These differences probably arose from incomplete mixing of nucleosynthetic material in the solar nebula. Chondritic meteorites have a slight excess of supernova-derived material as compared to Earth, demonstrating that the solar nebula was not perfectly homogenized upon formation. PMID:17023611

Ranen, Michael C; Jacobsen, Stein B

2006-11-01

416

Barium Isotopes in Chondritic Meteorites: Implications for Planetary Reservoir Models  

NASA Astrophysics Data System (ADS)

High-precision barium isotope measurements yielded differences of up to 25 parts per million in the 137Ba/136Ba ratio and 60 parts per million in the 138Ba/136Ba ratio between chondrites and Earth. These differences probably arose from incomplete mixing of nucleosynthetic material in the solar nebula. Chondritic meteorites have a slight excess of supernova-derived material as compared to Earth, demonstrating that the solar nebula was not perfectly homogenized upon formation.

Ranen, Michael C.; Jacobsen, Stein B.

2006-11-01

417

Barium ferrite powders prepared by milling and annealing  

Microsoft Academic Search

Purpose: Microstructure and magnetic properties analysis of barium ferrite powder obtained by milling and heat treatment. Design\\/methodology\\/approach: The milling process was carried out in a vibratory mill, which generated vibrations of the balls and milled material inside the container during which their collisions occur. After milling process the powders were annealed in electric chamber furnace. The X-ray diffraction methods were

R. Nowosielski; R. Babilas; G. Dercz; J. Wrona

418

Microstructure of composite material with powders of barium ferrite  

Microsoft Academic Search

Purpose: The aim of the present work is the microstructure characterization of commercial powder BaFe12O19 (as-prepared) and composite material with BaFe12O19 powders and polymer matrix, using XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscopy) methods. Design\\/methodology\\/approach: The morphology of barium ferrite powders and a fracture surface of the examined composite material was realized by using the scanning electron microscope. The

R. Nowosielski; R. Babilas; G. Dercz; L. Paj?k b

419

Microstructure and magnetic properties of commercial barium ferrite powders  

Microsoft Academic Search

Purpose: Microstructural and magnetic properties analysis of commercial barium ferrite powder BaFe12O19. Design\\/methodology\\/approach: The X-ray diffraction methods were utilized not only for qualitative and quantitative phase analysis of studied powder sample, but also for the determination of lattice parameters, crystallite size and the lattice distortion. The Rietveld method was used in the verification of the qualitative phase composition and in

R. Nowosielski; R. Babilas; J. Wrona

420

Study of formation mechanism of barium hexaferrite by sintering curve  

Microsoft Academic Search

Barium hexaferrite (BaFe12O19) with hexagonal structure was fabricated by sintering the mixture of ?-Fe2O3 and BaCO3, ball milling of the mixture followed by heat treatment as well as glycin–nitrate method and subsequent heat treatment, respectively. The mechanism of formation of the BaFe12O19 in the three kinds of procedures was investigated by using sintering shrinkage curve and XRD measurements. It was

H. Z. Wang; Q. He; G. H. Wen; F. Wang; Z. H. Ding; B. Yao

2010-01-01

421

Microwave-Induced Combustion Synthesis of Hexagonal Barium Ferrite Powders  

Microsoft Academic Search

A novel ceramic synthesis technique, microwave-assisted process was investigated for the production of Barium Hexagonal ferrite (BaFe^Oip) powders with improved physical properties. Compared to conventional synthetic route, the new method significantly shortened synthetic steps and reaction time. This technique involves the reaction of stoichiometric amount of metal nitrates and appropriate dosage of citric acid at microwave oven and the whole

Dong Limin; Han Zhidong; Wu Ze; Zhang Xianyou

2007-01-01

422

Crystallographic properties of magnetron sputtered barium ferrite films  

Microsoft Academic Search

The development of devices combining a ferrite with a semiconductor chip is a major focus of current research. Barium hexaferrite (BaFe12O19 or BaM) thick films are deposited here using a RF magnetron sputtering system. Films are amorphous and non magnetic after deposition. Post-deposition thermal annealing is employed to make the films crystallize. The effects of the substrate, thermal annealing process,

S. Capraro; M. Le Berre; J. P. Chatelon; B. Bayard; H. Joisten; C. Canut; D. Barbier; J. J. Rousseau

2004-01-01

423

Radium and barium in the Amazon River system  

Microsoft Academic Search

Data for ²²⁶Ra and ²²⁸Ra in the Amazon River system show that the activity of each radium isotope is strongly correlated with barium concentrations. Two trends are apparent, one for rivers which drain shield areas and another for all other rivers. These data suggest that there has been extensive fractionation of U, Th, and Ba during weathering in the Amazon

Willard S. Moore; John M. Edmond

1984-01-01

424

Adequacy of preparation for barium enema among elderly outpatients.  

PubMed Central

OBJECTIVE: To determine whether outpatients 75 years of age or older have a higher rate of inadequate bowel preparation for barium enema and of complications associated with the preparation and the test than patients aged 55 to 74 years. DESIGN: Cross-sectional survey. SETTING: Radiology department in a teaching hospital. PATIENTS: Patients 55 years or older referred for a barium enema from March to August 1988. OUTCOME MEASURES: All films were reviewed independently by a study radiologist blind to the staff radiologist's report. Patients were interviewed by telephone within several days after the test to assess the occurrence of problems during the preparation or the test. MAIN RESULTS: Of the 213 patients assessed 72 were excluded: 43 refused to participate or could not be contacted, 16 had previously undergone colonic surgery, and 13 were excluded for other reasons. The remaining 141 patients were separated into three age groups: those 55 to 64 years (46 patients), those 65 to 74 (47) and those 75 or older (48). In 104 cases (74%) the bowel had been prepared adequately; there was no significant difference between the three groups with regard to the adequacy of preparation. The incidence of problems reported by the patients did not differ significantly between the groups. CONCLUSIONS: Outpatients aged 75 years or more are no more likely than those aged 55 to 74 to have problems with bowel preparation or the barium enema itself. Age should not be a criterion for exclusion from barium enema. To try to lower the rate of poor bowel preparation clinicians and radiologists should consider counselling patients more carefully about the importance of proper preparation. Also, the current method of preparation could be examined to determine whether simple changes would significantly improve colon cleanliness. PMID:2025821

Grad, R M; Clarfield, A M; Rosenbloom, M; Perrone, M

1991-01-01

425

Isotopic Masses of Hydrogen, Chlorine, Barium, Cerium, and Neodymium  

Microsoft Academic Search

The 16-in. double-focusing mass spectrometer at the University of Minnesota has been employed to measure the atomic mass of H1 and the atomic masses and isotopic mass differences of chlorine, barium, cerium, and neodymium. Recent improvements in instrumentation have increased the precision of both narrow and wide doublet measurements. The doublet C11H22-C12H10 was used to relate the H1 mass directly

Jay L. Benson; Walter H. Johnson

1966-01-01

426

Preparation and magnetic properties of (Zn-Sn) substituted barium hexaferrite nanoparticles for magnetic recording  

NASA Astrophysics Data System (ADS)

Zn-Sn substituted barium ferrite particles BaFe 12-2 xZn xSn xO 19 with 0? x?1.1 have been prepared by a chemical co-precipitation method for the first time. X-ray diffraction (XRD) and transition electron microscopy (TEM) have been carried out to determine the particle structure and morphology. Magnetic properties have been measured using a vibrating sample magnetometer (VSM) with an applied field up to 80 kOe. The specific saturation magnetization Ms was determined using the law of approach to saturation, and the effective anisotropy field Ha and anisotropy constant K1 were also estimated. It was found that the particle size could be effectively decreased and coercivity Hc easily controlled, by varying x without significantly decreasing saturation magnetization. In particular, BaFe 12-2 xZn xSn xO 19 with x=0.7-1.1 has suitable magnetic characteristics and a particle size small enough for high-density magnetic recording.

Fang, H. C.; Yang, Z.; Ong, C. K.; Li, Y.; Wang, C. S.

1998-08-01

427

Dissimilatory bacterial sulfate reduction in montana groundwaters  

Microsoft Academic Search

The origin of hydrogen sulfide in southeastern Montana groundwaters was investigated. Sulfate?reducing bacteria were detected in 25 of 26 groundwater samples in numbers ranging from 2.0 × 10 to greater than 2.4 × 10 bacteria per 100 ml. Stable sulfur isotope fractionation studies indicated a biological role in sulfate reduction. However, sulfate?reducing activity as determined by use of a radioactive

William S. Dockins; Gregory J. Olson; Gordon A. McFeters; Susan C. Turbak

1980-01-01

428

Structure and multiferroic properties of barium hexaferrite ceramics  

NASA Astrophysics Data System (ADS)

Simultaneous occurrence of large ferroelectricity and strong ferromagnetism have been observed in barium hexaferrite ceramics. Barium hexaferrite (BaFe12O19) 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 BaFe12O19 ceramics at room temperature, revealing a clear ferroelectric hysteresis loop. The maximum remanent polarization of the BaFe12O19 ceramic was estimated approximately 11.8 ?C cm-2. The FeO6 octahedron in its perovskite-like hexagonal unit cell and the shift of Fe3+ off the center of octahedron are suggested to be the origin of the polarization in BaFe12O19. The BaFe12O19 ceramics also showed strong ferromagnetism at room temperature.

Tan, Guolong; Chen, Xiuna

2013-02-01

429

The Tordo 1 polar cusp barium plasma injection experiment  

NASA Technical Reports Server (NTRS)

In January 1975, two barium plasma injection experiments were carried out with rockets launched into the upper atmosphere where field lines from the dayside cusp region intersect the ionosphere. The Tordo 1 experiment took place near the beginning of a worldwide magnetic storm. It became a polar cap experiment almost immediately as convection perpendicular to the magnetic field moved the fluorescent plasma jet away from the cusp across the polar cap in an antisunward direction. Convection across the polar cap with an average velocity of more than 1 km/s was observed for nearly 40 min until the barium flux tubes encountered large electron fields associated with a poleward bulge of the auroral oval near Greenland. Prior to the encounter with the aurora near Greenland there is evidence of upward acceleration of the barium ions while they were in the polar cap. The three-dimensional observations of the plasma orientation and motion give an insight into convection from the cusp region across the polar cap, the orientation of the polar cap magnetic field lines out to several earth radii, the causes of polar cap magnetic perturbations, and parallel acceleration processes.

Wescott, E. M.; Stenbaek-Nielsen, H. C.; Davis, T. N.; Jeffries, R. A.; Roach, W. H.

1978-01-01

430

Orbital barium CRRES injection - effective source of ionospheric wavelike disturbances  

NASA Astrophysics Data System (ADS)

Spectral analysis of artificial wavelike disturbances (WD) in ionospheric parameters is presented. The sources of WD are barium clouds injections in Combined Release and Radiation Effects Satellite (CRRES) perigee experiments. Plasma concentration pulsations are found in the ionospheric F2 layer maximum over Havana (Cuba) at distances 1500-2500 km from the barium injection. It was found that for the spectral component with 10 min period, the delay (relative to injection moment) corresponded to WD propagation velocity in 323-390 m/s band and depended on the specific injection conditions. It was shown that in every experiment the WD effective propagation velocity in the terminator region correlated with the sunlit part of the trajectory from the injection point to Havana. When comparing this WD type with WD's of other origins (from earthquakes, high-altitude explosions and solar terminator), it was shown that purposeful injection in the ionosphere of even a small barium quantity with orbital velocity in terminator region might be the effective means for generation or amplification of natural WD.

Ruzhin, Yu. Ya.; Oraevsky, V. N.; Depueva, A. Kh.; Perez, H.; Palasio, L.

431

Mechanism of action of barium ion on rat aortic smooth muscle.  

PubMed

The mechanism of action of barium ion on the aortic smooth muscle of the normal rat was investigated using in vitro calcium-depleted aortic strips. Aortic strips were depleted of calcium by repeated exposure to norepinephrine in a calcium-free bathing solution. Although calcium depletion abrogated the response of strips to catecholamines and depolarizing agents, the response to barium chloride remained quantitatively intact. The calcium influx blocker D 600 prevented the contractile response to barium but not to catecholamines, whereas phentolamine prevented the response to catecholamines but not barium. The strip response to barium was depressed by a twofold increase in extracellular magnesium concentration whether the strip was intact or calcium depleted. Although increased concentrations of calcium in the extracellular medium inhibited the contractile response to potassium ion, increases in barium merely potentiated the potassium contracture. These findings indicate that barium produces its contractile effect on vascular smooth muscle by a direct intracellular interaction with the contractile or regulatory proteins. Barium enters these cells via calcium influx channels and is probably not sequestered in a physiologically releasable pool. Unlike calcium, barium does not stabilize the smooth muscle sarcolemma when present in high concentration. PMID:6703038

Hansen, T R; Dineen, D X; Petrak, R

1984-03-01

432

Semi-synthesis of chondroitin sulfate-E from chondroitin sulfate-A  

PubMed Central

Chondroitin sulfate-E (chondroitin-4, 6-disulfate) was prepared from chondroitin sulfate-A (chondroitin-4 - sulfate) by regioselective sulfonation, performed using trimethylamine sulfur trioxide in formamide under argon. The structure of semi-synthetic chondroitin sulfate-E was analyzed by PAGE, 1H NMR, 13C NMR, 2D NMR and disaccharide analysis and compared with natural chondroitin sulfate-E. Both semi-synthetic and natural chondroitin sulfate-E were each biotinylated and immobilized on BIAcore SA biochips and their interactions with fibroblast growth factors displayed very similar binding kinetics and binding affinities. The current semi-synthesis offers an economical approach for the preparation of the rare chondroitin sulfate-E from the readily available chondroitin sulfate-A. PMID:22140285

Cai, Chao; Solakyildirim, Kemal; Yang, Bo; Beaudet, Julie M.; Weyer, Amanda; Linhardt, Robert J.; Zhang, Fuming

2011-01-01

433

Nickel Solubility and Precipitation in Soils: A Thermodynamic Study  

SciTech Connect

The formation of mixed-metal-Al layered double hydroxide (LDH) phases similar to hydrotalcite has been identified as a significant mechanism for immobilization of trace metals in some environmental systems. These precipitate phases become increasingly stable as they age, and their formation may therefore be an important pathway for sequestration of toxic metals in contaminated soils. However, the lack of thermodynamic data for LDH phases makes it difficult to model their behavior in natural systems. In this work, enthalpies of formation for Ni LDH phases with nitrate and sulfate interlayers were determined and compared to recently published data on carbonate interlayer LDHs. Differences in the identity of the anion interlayer resulted in substantial changes in the enthalpies of formation of the LDH phases, in the order of increasing enthalpy carbonate<sulfateprecipitates. Both mechanical mixture and solid-solution models could be used to predict the thermodynamic properties of the LDH phases. Modeling results based on these thermodynamic data indicated that the formation of LDH phases on soil mineral substrates decreased Ni solubility compared to Ni(OH)2 over pH 5-9 when soluble Al is present in the soil substrate. Over time, both of these precipitate phases will transform to more stable Ni phyllosilicates.

Peltier,E.; Allada, R.; Navrotsky, A.; Sparks, D.

2006-01-01

434

A modified sulfate process to lunar oxygen  

NASA Technical Reports Server (NTRS)

A modified sulfate process which produces oxygen from iron oxide-bearing minerals in lunar soil is under development. Reaction rates of ilmenite in varying strength sulfuric acid have been determined. Quantitative conversion of ilmenite to ferrous sulfate was observed over a range of temperatures and concentrations. Data has also been developed on the calcination of by-product sulfates. System engineering for overall operability and simplicity has begun, suggesting that a process separating the digestion and sulfate dissolution steps may offer an optimum process.

Sullivan, Thomas A.

1992-01-01

435

Precipitation Indices Low Countries  

NASA Astrophysics Data System (ADS)

Since 1995, KNMI published a series of books(1), presenting an annual reconstruction of weather and climate in the Low Countries, covering the period AD 763-present, or roughly, the last millennium. The reconstructions are based on the interpretation of documentary sources predominantly and comparison with other proxies and instrumental observations. The series also comprises a number of classifications. Amongst them annual classifications for winter and summer temperature and for winter and summer dryness-wetness. The classification of temperature have been reworked into peer reviewed (2) series (AD 1000-present) of seasonal temperatures and temperature indices, the so called LCT (Low Countries Temperature) series, now incorporated in the Millennium databases. Recently we started a study to convert the dryness-wetness classifications into a series of precipitation; the so called LCP (Low Countries Precipitation) series. A brief outline is given here of the applied methodology and preliminary results. The WMO definition for meteorological drought has been followed being that a period is called wet respectively dry when the amount of precipitation is considerable more respectively less than usual (normal). To gain a more quantitative insight for four locations, geographically spread over the Low Countries area (De Bilt, Vlissingen, Maastricht and Uccle), we analysed the statistics of daily precipitation series, covering the period 1900-present. This brought us to the following definition, valid for the Low Countries: A period is considered as (very) dry respectively (very) wet if over a continuous period of at least 60 days (~two months) cq 90 days (~three months) on at least two out of the four locations 50% less resp. 50% more than the normal amount for the location (based on the 1961-1990 normal period) has been measured. This results into the following classification into five drought classes hat could be applied to non instrumental observations: Very wet period (+2): Wide scale river flooding, marshy acres and meadows.-Farmers cope with poor harvests of hay, grains, fruit etc. resulting in famines.-Late grape harvests, poor yield quantity and quality of wine. Wet period (+1): High water levels cq discharges of major rivers, tributaries and brooks, local river floodings, marshy acres and meadows in the low lying areas.-Wearisome and hampered agriculture. Normal (0) Dry period (-1): Low water levels cq discharges of major rivers, tributaries and brooks. Some brooks may dry up.-Summer half year: local short of yield of grass, hay and other forage.-Summer half year: moor-, peat- and forest fires. Very dry period (-2): Very low water levels cq discharges of major rivers and tributaries. Brooks and wells dry up. Serious shortage of drinking water; especially in summer.-Major agricultural damage, shortage of water, mortality stock of cattle. Shortage of grain. Flour can not be produced due to water mills running out of water, shortage of bread, bread riots, famines.-Large scale forest and peat areas, resulting in serious air pollution. Town fires. By verifying the historical evidence on these criterions, a series of 5 step indices ranging from very dry to very wet for summer and winter half year of the Low Countries was obtained. Subsequently these indices series were compared with the instrumentally observed seasonal precipitation sums for De Bilt (1735-2008), which is considered to be representative for the Central Netherlands. For winter (Oct-March) and summer half year (Apr.-Sept.) the accumulated precipitation amounts are calculated; these amounts are approximately normally distributed. Based on this distribution, the cumulative frequency distribution is calculated. By tabulating the number of summers in the pre-instrumental period 1201-1750 for each of the drought classes, a distribution is calculated which is then related to the modern accumulated precipitation distribution. Assuming that the accumulated precipitation amount has not been below (above) the mean precipitation minus (plus) three standard deviations for

van Engelen, A. F. V.; Ynsen, F.; Buisman, J.; van der Schrier, G.

2009-09-01

436

Long-term trends in precipitation chemistry in southern California  

SciTech Connect

Southern California Edison (SCE) operated an acid precipitation chemistry monitoring program in the South Coast Air Basin (SoCAB) from June 1979 through June 1991, with data collected over a period of 12 rain years. A total of more than 7,000 sequential, wet-only event precipitation samples were collected from 60 stations in the SoCAB, with the number and location of stations varying from year to year. However, 10 sampling locations were operated for at least 7 years. The network of monitoring sites was established to gather data for analysis of the spatial and temporal distribution of pollutants (e.g., pH, sulfate, nitrate, and trace metals) in the precipitation on an event basis. These data were used to investigate the long-term spatial and temporal trends in precipitation chemistry. Overall, the pH showed a slight upward trend over the study years. No other species showed significant long-term trends. Trends of precipitation chemistry do not match observed trends in ambient air quality or reported emission reductions during the study years.

Chinkin, L.R.; Main, H.H. [Sonoma Technology, Inc., Santa Rosa, CA (United States); Collins, J.F. [Collins Computing and Consulting, Somis, CA (United States); Young, J.R. [Southern California Edison, Rosemead, CA (United States)

1995-12-31

437

RADIOACTIVE INDICATOR DETERMINATION OF ZIRCONIUM AND PLUTONIUM DOUBLE SULFATES IN SATURATED POTASSIUM SULFATE SOLUTIONS  

Microsoft Academic Search

Zirconium and plutonium double sulfates were prepared by mixing in ; saturated potassium sulfate solution. The data indicate the absence of plutonium ; salt hydrolysis. The compositions of the double sulfates of plutonium(IV) and ; zirconium with potassium bisulf ate prepared under identical conditions are \\/sub ; 3\\/nt, KâPu(SOâ)â and KâZr(SOâ) ). (R. V.J.);

Bobrova

1960-01-01

438

Metallic particles to stimulate sulfate reduction: A new approach for Bioremediation in low pH streams  

NASA Astrophysics Data System (ADS)

Extensive research has been carried out on efficiency of ZVI (Zero Valent Iron) and SRB (Sulfate Reducing Bacteria) for treatment of inorganics in contaminated groundwaters. ZVI is proved as a potential remediation agent due to multiple ZVI-metal interactions such as surface complexation, reduction and (co) precipitation. But little information is available till date on stability of precipitates, which is very important while dealing subsurface processes. SRB's are well known for metal removal and stable precipitates, but most of the time, the pH in mining areas are significantly low, which either restrict the stimulation of SRB or requires extra substrate and time. During anaerobic corrosion, ZVI deplete O2 and produce water derived H2, resulting an increase in pH and decrease in redox potential which makes it very efficient in low pH plumes. Moreover, SRB can potentially use this hydrogen as an electron donor to raise biomass yield significantly to accelerate reductive sulfate removal. The main objective of this research was to determine whether the combination of SRB and ZVI can improve the rate of contaminant removal and stability of precipitates. Within the framework of this study, we tested experimentally different parameters: concentration and particle size (ranging from 70 nm to 300 mm) of ZVI to stimulate sulfate reduction for subsequent removal of metals such as As, Cd and Zn in groundwaters and sediments with low pH (~3). Stability of precipitates was studied as well in flowthrough columns by changing pH and redox conditions. In our experiment, we find that ZVI is very efficient in stimulating sulfate reduction, fast removal of contaminants and more stable precipitates "This is a contribution of the AquaTRAIN MRTN (Contract No. MRTN-CT-2006-035420) funded under the European Commission Sixth Framework Programme (2002-2006) Marie Curie Actions, Human Resources & Mobility Activity Area - Research Training Networks"

Kumar, Naresh; Bastiaens, Leen; Vanbroekhoven, Karolien; Millot, Romain; Battaglia-Brunet, Fabienne; Diels, Ludo

2010-05-01

439

Hydrologic Fluctuations Resulting From Climatic Variability Cause Methylation Events in Peatlands Impacted by Elevated Sulfate Deposition  

NASA Astrophysics Data System (ADS)

A long-term sulfate addition experiment at the Marcell Experimental Forest of northern Minnesota has demonstrated the stimulatory effect of sulfate on mercury methylation at the ecosystem scale. Wetland margins have been shown to be principal zones of methylmercury (MeHg) production in sulfur-limited peatlands, but this research illustrates how the hydrologically isolated center of a small peatland effectively becomes a hot spot when exposed to elevated, atmospheric sulfate deposition. Furthermore, the chronic effects resulting from experimentally elevated sulfate deposition lead to the formation of a pool of reduced sulfur compounds highly sensitive to the changing redox conditions created by hydrologic and climatic variability. Our data reveal that water table rises following extended periods of drought cause natural "sulfate additions" and stimulate mercury methylation. This phenomenon was even observed in our control treatment following a severe drought in 2006. Hydrologic events that increase connectivity between the central bog and dominant wetland flowpaths, such as the infrequent, intense precipitation events predicted for this region by climate change models, could significantly increase MeHg flux from similar wetland systems.

Coleman Wasik, J. K.; Engstrom, D. R.; Swain, E. B.; Monson, B. A.; Balogh, S. J.; Jeremiason, J. D.; Kolka, R. K.; Mitchell, C. P.; Branfireun, B. A.; Almendinger, J. E.

2008-12-01

440

Collapsin response mediator proteins of neonatal rat brain interact with chondroitin sulfate.  

PubMed

Chondroitin sulfate proteoglycans are structurally and functionally important components of the extracellular matrix of the central nervous system. Their expression in the developing mammalian brain is precisely regulated, and cell culture experiments implicate these proteoglycans in the control of cell adhesion, neuron migration, neurite formation, neuronal polarization, and neuron survival. Here, we report that a monoclonal antibody against chondroitin sulfate-binding proteins from neonatal rat brain recognizes collapsin response mediator protein-4 (CRMP-4), which belongs to a family of proteins involved in collapsin/semaphorin 3A signaling. Soluble CRMPs from neonatal rat brain bound to chondroitin sulfate affinity columns, and CRMP-specific antisera co-precipitated chondroitin sulfate. Moreover, chondroitin sulfate and CRMP-4 were found to be localized immuno-histochemically in overlapping distributions in the marginal zone and the subplate of the cerebral cortex. CRMPs are released to culture supernatants of NTera-2 precursor cells and of neocortical neurons after cell death, and CRMP-4 is strongly expressed in the upper cortical plate of neonatal rat where cell death is abundant. Therefore, naturally occurring cell death is a plausible mechanism that targets CRMPs to the extracellular matrix at certain stages of development. In summary, our data indicate that CRMPs, in addition to their role as cytosolic signal transduction molecules, may subserve as yet unknown functions in the developing brain as ligands of the extracellular matrix. PMID:12444086

Franken, Sebastian; Junghans, Ulrich; Rosslenbroich, Volker; Baader, Stephan L; Hoffmann, Ralf; Gieselmann, Volkmar; Viebahn, Christoph; Kappler, Joachim

2003-01-31

441

Precipitation and recovery of metal sulfides from metal containing acidic wastewater in a sulfidogenic down-flow fluidized bed reactor.  

PubMed

This study reports the feasibility of recovering metal precipitates from a synthetic acidic wastewater containing ethanol, Fe, Zn, and Cd at an organic loading rate of 2.5 g COD/L-day and a COD to sulfate ratio of 0.8 in a sulfate reducing down-flow fluidized bed reactor. The metals were added at increasing loading rates: Fe from 104 to 320 mg/L-day, Zn from 20 to 220 mg/L-day, and Cd from 5 to 20 mg/L-day. The maximum COD and sulfate removals attained were 54% and 41%, respectively. The biofilm reactor was operated at pH as low as 5.0 with stable performance, and no adverse effect over COD consumption or sulfide production was observed. The metals precipitation efficiencies obtained for Fe, Zn, and Cd exceeded 99.7%, 99.3%, and 99.4%, respectively. The total recovered precipitate was estimated to be 90% of the theoretical mass expected as metal sulfides. The precipitate was mainly recovered from the bottom of the reactor and the equalizer. The analysis of the precipitates showed the presence of pyrite (FeS2), sphalerite (ZnS) and greenockite (CdS); no metal hydroxides or carbonates in crystalline phases were identified. This study is the first in reporting the feasibility to recover metal sulfides separated from the biomass in a sulfate reducing process in one stage. PMID:18846546

Gallegos-Garcia, Marisol; Celis, Lourdes B; Rangel-Méndez, René; Razo-Flores, Elías

2009-01-01

442

Geochemical and isotopic composition of ground water with emphasis on sources of sulfate in the upper Floridan Aquifer in parts of Marion, Sumter, and Citrus counties, Florida  

USGS Publications Warehouse

In inland areas of northwest central Florida, sulfate concentrations in the Upper Floridan aquifer are extremely variable and sometimes exceed drinking water standards (250 milligrams per liter). This is unusual because the aquifer is unconfined and near the surface, allowing for active recharge. The sources of sulfate and geochemical processes controlling ground-water composition were evaluated in this area. Water was sampled from thirty-three wells in parts of Marion, Sumter, and Citrus Counties, within the Southwest Florida Water Management District; these included at least a shallow and a deep well at fifteen separate locations. Ground water was analyzed for major ions, selected trace constituents, dissolved organic carbon, and stable isotopes (sulfur-34 of sulfate and sulfide, carbon-13 of inorganic carbon, deuterium, and oxygen-18). Sulfate concentrations ranged from less than 0.2 to 1,400 milligrams per liter, with higher sulfate concentrations usually in water from deeper wells. The samples can be categorized into a low sulfate group (less than 30 milligrams per liter) and a high sulfate group (greater than 30 milligrams per liter). For the high sulfate water, concentrations of calcium and magnesium increased concurrently with sulfate. Chemical and isotopic data and mass-balance modeling indicate that the composition of high sulfate waters is controlled by dedolomitization reactions (dolomite dissolution and calcite precipitation, driven by dissolution of gypsum). Gypsum occurs deeper in the aquifer than open intervals of sampled wells. Upward flow has been documented in deeper parts of the aquifer in the study area, which may be driven by localized discharge areas or rapid flow in shallow parts of the aquifer. Mixing between shallow ground water and sulfate-rich water that dissolved gypsum at the base of the aquifer is probably responsible for the range of concentrations observed in the study area. Other solutes that increased with sulfate apparently originate from the gypsum itself, from other mineral assemblages found deeper in the aquifer in association with gypsum, and from residual seawater from less- flushed, deeper parts of the aquifer. These ions are subsequently transported with sulfate to shallower parts of the aquifer where gypsum is not present. The composition of low sulfate ground water is controlled by differences in the extent of microbially mediated reactions, which produce carbon dioxide. This, in turn, influences the extent of calcite dissolution. Ground waters which underwent limited microbial reactions contained dissolved oxygen and were usually in ridge areas where recharge typically is rapid. Anaerobic waters were in lower lying areas of Sumter County, where soils are poorly drained and aquifer recharge is slow. Anaerobic waters had higher concentrations of calcium, bicarbonate, sulfide, dissolved organic carbon, iron, manganese, and silica, and had lower concentrations of nitrate than aerobic ground waters. For low sulfate waters, sulfate generally originates from meteoric sources (atmospheric precipitation), with variable amounts of oxidation of reduced sulfur and sulfate reduction. Sulfide is sometimes removed from solution, probably by precipitation of a sulfide minerals such as pyrite. In areas where deep ground water has low sulfate concentrations, the shallow flow system is apparently deeper than where high sulfate concentrations occur, and upwelling sulfate-rich water is negligible. The range of sulfate concentrations observed in the study areas and differences in sulfate concentrations with depth indicate a complex interaction between shallow and deep ground-water flow systems.

Sacks, Laura A.

1996-01-01

443

Acid Sulfate Weathering on Mars: Results from the Mars Exploration Rover Mission  

NASA Technical Reports Server (NTRS)

Sulfur has played a major role in the formation and alteration of outcrops, rocks, and soils at the Mars Exploration Rover landing sites on Meridiani Planum and in Gusev crater. Jarosite, hematite, and evaporite sulfates (e.g., Mg and Ca sulfates) occur along with siliciclastic sediments in outcrops at Meridiani Planum. The occurrence of jarosite is a strong indicator for an acid sulfate weathering environment at Meridiani Planum. Some outcrops and rocks in the Columbia Hills in Gusev crater appear to be extensively altered as suggested by their relative softness as compared to crater floor basalts, high Fe(3+)/FeT, iron mineralogy dominated by nanophase Fe(3+) oxides, hematite and/or goethite, corundum-normative mineralogies, and the presence of Mg- and Casulfates. One scenario for aqueous alteration of these rocks and outcrops is that vapors and/or fluids rich in SO2 (volcanic source) and water interacted with rocks that were basaltic in bulk composition. Ferric-, Mg-, and Ca-sulfates, phosphates, and amorphous Si occur in several high albedo soils disturbed by the rover's wheels in the Columbia Hills. The mineralogy of these materials suggests the movement of liquid water within the host material and the subsequent evaporation of solutions rich in Fe, Mg, Ca, S, P, and Si. The presence of ferric sulfates suggests that these phases precipitated from highly oxidized, low-pH solutions. Several hypotheses that invoke acid sulfate weathering environments have been suggested for the aqueous formation of sulfate-bearing phases on the surface of Mars including (1) the oxidative weathering of ultramafic igneous rocks containing sulfides; (2) sulfuric acid weathering of basaltic materials by solutions enriched by volcanic gases (e.g., SO2); and (3) acid fog (i.e., vapors rich in H2SO4) weathering of basaltic or basaltic-derived materials.

Ming, Douglas W.; Morris, R. V.; Golden, D. C.

2006-01-01

444

Inhibition of sulfate reducing bacteria in aquifer sediment by iron nanoparticles.  

PubMed

Batch microcosms were setup to determine the impact of different sized zero valent iron (Fe(0)) particles on microbial sulfate reduction during the in situ bio-precipitation of metals. The microcosms were constructed with aquifer sediment and groundwater from a low pH (3.1), heavy-metal contaminated aquifer. Nano (nFe(0)), micro (mFe(0)) and granular (gFe(0)) sized Fe(0) particles were added to separate microcosms. Additionally, selected microcosms were also amended with glycerol as a C-source for sulfate-reducing bacteria. In addition to metal removal, Fe(0) in microcosms also raised the pH from 3.1 to 6.5, and decreased the oxidation redox potential from initial values of 249 to -226 mV, providing more favorable conditions for microbial sulfate reduction. mFe(0) and gFe(0) in combination with glycerol were found to enhance microbial sulfate reduction. However, no sulfate reduction occurred in the controls without Fe(0) or in the microcosm amended with nFe(0). A separate dose test confirmed the inhibition for sulfate reduction in presence of nFe(0). Hydrogen produced by Fe(0) was not capable of supporting microbial sulfate reduction as a lone electron donor in this study. Microbial analysis revealed that the addition of Fe(0) and glycerol shifted the microbial community towards Desulfosporosinus sp. from a population initially dominated by low pH and metal-resisting Acidithiobacillus ferrooxidans. PMID:24388832

Kumar, Naresh; Omoregie, Enoma O; Rose, Jerome; Masion, Armand; Lloyd, Jonathan R; Diels, Ludo; Bastiaens, Leen

2014-03-15

445

Precipitation hardening austenitic superalloys  

DOEpatents

Precipitation hardening, austenitic type superalloys are described. These alloys contain 0.5 to 1.5 weight percent silicon in combination with about 0.05 to 0.5 weight percent of a post irradiation ductility enhancing agent selected from the group of hafnium, yttrium, lanthanum and scandium, alone or in combination with each other. In addition, when hafnium or yttrium are selected, reductions in irradiation induced swelling have been noted.

Korenko, Michael K. (Wexford, PA)

1985-01-01

446

Precipitation hardening austenitic superalloys  

Microsoft Academic Search

Precipitation hardening, austenitic type superalloys are described. These alloys contain 0.5 to 1.5 weight percent silicon in combination with about 0.05 to 0.5 weight percent of a post irradiation ductility enhancing agent selected from the group of hafnium, yttrium, lanthanum and scandium, alone or in combination with each other. In addition, when hafnium or yttrium are selected, reductions in irradiation

Korenko; Michael K

1985-01-01

447

Effects of acid precipitation  

Microsoft Academic Search

Acid precipitation, including dry deposition, is recognized as coming from pollution-caused strong acid precursors that result from the burning of fossil fuels. Recent studies suggest that ecosystems susceptible to acidification occur over the entire length of the Appalachian Mountains and certain other regions of the eastern U.S. This paper reviews a short-term assessment by the EPA to survey the extent

Norman R. Glass; Dean E. Arnold; James N. Galloway; George R. Hendrey; Jeffrey J. Lee; W. W. McFee; Stephen A. Norton; Charles F. Powers; Danny L. Rambo; Carl L. Schofield

1982-01-01

448

Annual variations in chemical composition of atmospheric precipitation, eastern North Carolina and southeastern Virginia  

USGS Publications Warehouse

A 2-year study of precipitation composition over eastern North Carolina and southeastern Virginia has been completed. Chemical analyses were made of the major ions in monthly rainfall samples from each of 12 sampling locations. Areal and seasonal distributions were determined for chloride, calcium, magnesium, sodium, potassium, sulfate, and nitrate. Annual changes in loads and in geographical distribution of sulfate and of nitrate are small. Yearly rainfall sulfate loads amount to approximately 7 tons per square mile, whereas deposition of nitrate is about 2 tons per square mile per year in the interior of the network and less near the coast. Areal patterns of chloride content are consistent with the assumption that the ocean is the only major source of rainfall chloride in the area. Chloride loads were 2.1 and 1.8 tons per square mile per year; the difference can be attributed to meteorological conditions. Cation concentrations in network precipitation appear to depend on localized sources, probably soil dust. Annual loads of the major cations are approximately 2 tons per square mile of calcium, 1.8 tons per square mile of sodium, 0.5 ton per square mile of magnesium, and 0.3 ton per square mile of potassium; considerable year-to-year differences were noted in these values. Bicarbonate and hydrogen ion in network rainfall are closely related to the relative concentrations of sulfate and calcium. Apparently, reaction of an acidic sulfur-containing aerosol with an alkaline calcium source is one of the principal controls on precipitation alkalinity and pH. Ions in precipitation contribute substantially to the quality of surface water in the network area. Comparisons between precipitation input and stream export of ions for four North Carolina rivers show that rainfall sulfate is equal to sulfate discharged, whereas nitrate in rain slightly exceeds stream nitrate. Contributions of cations to the streams by way of precipitation range from about 20 percent for potassium to almost 50 percent for calcium. Chloride deposited by precipitation amounts to about one-fourth of the stream load. Additions of manufactured salt may account for much of the remainder of the surface-water load.

Fisher, Donald W.

1967-01-01

449

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

PubMed

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. PMID:24844320

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

2014-08-01

450

Weak Carbon-Hydrogen-Nitrogen Interactions Affect the Heterocyclic Ligand Bonding Modes in Barium Complexes Containing 2-Tetrazolato  

E-print Network

Weak Carbon-Hydrogen-Nitrogen Interactions Affect the Heterocyclic Ligand Bonding Modes in Barium calculations of barium complexes of the formula Ba- (azolate)2(18-crown-6). With dimethylaminotetrazolate [CN4

Schlegel, H. Bernhard

451

Project EARTH-12-GMH2: Cadmium and barium isotopes as tracers of modern and past ocean processes  

E-print Network

Project EARTH-12-GMH2: Cadmium and barium isotopes as tracers of modern and past ocean processes Supervisor: Professor Gideon Henderson Cadmium and barium both show surface depletion in the oceans, are both

Henderson, Gideon

452

4, 23232360, 2007 Extreme precipitation  

E-print Network

HESSD 4, 2323­2360, 2007 Extreme precipitation and extreme streamflow W. Wang et al. Title Page are under open-access review for the journal Hydrology and Earth System Sciences Extreme precipitation Correspondence to: W. Wang (w.wang@126.com) 2323 #12;HESSD 4, 2323­2360, 2007 Extreme precipitation and extreme

Boyer, Edmond

453

REGIONAL ANALYSIS OF EXTREME PRECIPITATION  

E-print Network

REGIONAL ANALYSIS OF EXTREME PRECIPITATION EVENTS IN THE CZECH REPUBLIC Jan Kyselý1 , Jan Picek2: - daily precipitation amounts measured at 78 stations covering the Czech Republic (area of 78 864 square the period of 1961-2000; there are no missing values in this dataset. Extreme precipitation events: - maximum

Jureckova, Jana

454

Critical phenomena in atmospheric precipitation  

E-print Network

LETTERS Critical phenomena in atmospheric precipitation OLE PETERS1,2,3 * AND J. DAVID NEELIN3 1 convection and precipitation (the order parameter)--with correlated regions on scales of tens to hundreds the climatological mean by an order of magnitude or more. Moist convection and the accompanying precipitation have

Loss, Daniel

455

Magnetospheric Processes Leading to Precipitation  

Microsoft Academic Search

Important causes of the precipitation of magnetospheric particles into the ionosphere are reviewed, and critical areas where further study is needed are identified. This review begins with a description of the precipitation that occurs within the region of open, polar-cap magnetic field lines. Precipitation of polar rain, cusp\\/mantle, and energetic solar particles is described as a result of the direct

L. R. Lyons

1997-01-01

456

Functionalized synchrotron in-line phase-contrast computed tomography: a novel approach for simultaneous quantification of structural alterations and localization of barium-labelled alveolar macrophages within mouse lung samples  

PubMed Central

Functionalized computed tomography (CT) in combination with labelled cells is virtually non-existent due to the limited sensitivity of X-ray-absorption-based imaging, but would be highly desirable to realise cell tracking studies in entire organisms. In this study we applied in-line free propagation X-ray phase-contrast CT (XPCT) in an allergic asthma mouse model to assess structural changes as well as the biodistribution of barium-labelled macrophages in lung tissue. Alveolar macrophages that were barium-sulfate-loaded and fluorescent-labelled were instilled intratracheally into asthmatic and control mice. Mice were sacrificed after 24?h, lungs were kept in situ, inflated with air and scanned utilizing XPCT at the SYRMEP beamline (Elettra Synchrotron Light Source, Italy). Single-distance phase retrieval was used to generate data sets with ten times greater contrast-to-noise ratio than absorption-based CT (in our setup), thus allowing to depict and quantify structural hallmarks of asthmatic lungs such as reduced air volume, obstruction of airways and increased soft-tissue content. Furthermore, we found a higher concentration as well as a specific accumulation of the barium-labelled macrophages in asthmatic lung tissue. It is believe that XPCT will be beneficial in preclinical asthma research for both the assessment of therapeutic response as well as the analysis of the role of the recruitment of macrophages to inflammatory sites. PMID:25537601

Dullin, Christian; dal Monego, Simeone; Larsson, Emanuel; Mohammadi, Sara; Krenkel, Martin; Garrovo, Chiara; Biffi, Stefania; Lorenzon, Andrea; Markus, Andrea; Napp, Joanna; Salditt, Tim; Accardo, Agostino; Alves, Frauke; Tromba, Giuliana

2015-01-01

457

Functionalized synchrotron in-line phase-contrast computed tomography: a novel approach for simultaneous quantification of structural alterations and localization of barium-labelled alveolar macrophages within mouse lung samples.  

PubMed

Functionalized computed tomography (CT) in combination with labelled cells is virtually non-existent due to the limited sensitivity of X-ray-absorption-based imaging, but would be highly desirable to realise cell tracking studies in entire organisms. In this study we applied in-line free propagation X-ray phase-contrast CT (XPCT) in an allergic asthma mouse model to assess structural changes as well as the biodistribution of barium-labelled macrophages in lung tissue. Alveolar macrophages that were barium-sulfate-loaded and fluorescent-labelled were instilled intratracheally into asthmatic and control mice. Mice were sacrificed after 24?h, lungs were kept in situ, inflated with air and scanned utilizing XPCT at the SYRMEP beamline (Elettra Synchrotron Light Source, Italy). Single-distance phase retrieval was used to generate data sets with ten times greater contrast-to-noise ratio than absorption-based CT (in our setup), thus allowing to depict and quantify structural hallmarks of asthmatic lungs such as reduced air volume, obstruction of airways and increased soft-tissue content. Furthermore, we found a higher concentration as well as a specific accumulation of the barium-labelled macrophages in asthmatic lung tissue. It is believe that XPCT will be beneficial in preclinical asthma research for both the assessment of therapeutic response as well as the analysis of the role of the recruitment of macrophages to inflammatory sites. PMID:25537601

Dullin, Christian; Dal Monego, Simeone; Larsson, Emanuel; Mohammadi, Sara; Krenkel, Martin; Garrovo, Chiara; Biffi, Stefania; Lorenzon, Andrea; Markus, Andrea; Napp, Joanna; Salditt, Tim; Accardo, Agostino; Alves, Frauke; Tromba, Giuliana

2015-01-01

458

Crystallization of chicken egg white lysozyme from assorted sulfate salts  

NASA Astrophysics Data System (ADS)

Chicken egg white lysozyme has been found to crystallize from ammonium, sodium, potassium, rubidium, magnesium, and manganese sulfates at acidic and basic pH, with protein concentrations from 60 to 190 mg/ml. Crystals have also been grown at 4°C in the absence of any other added salts using isoionic lysozyme which was titrated to pH 4.6 with dilute sulfuric acid. Four different crystal forms have been obtained, depending upon the temperature, protein concentration, and precipitating salt employed. Crystals grown at 15°C were generally tetragonal, with space group P4 32 12. Crystallization at 20°C typically resulted in the formation of orthorhombic crystals, space group P2 12 12 1. The tetragonal ? orthorhombic transition appeared to be a function of both the temperature and protein concentration, occurring between 15 and 20°C and between 100 and 125 mg/ml protein concentration. Crystallization from 1.2 M magnesium sulfate at pH 7.8 gave a trigonal crystal, space group P3 12 1, a= b=87.4, c=73.7, ?=120°, which diffracted to 2.8 Å. Crystallization from ammonium sulfate at pH 4.6, generally at lower temperatures, was also found to result in a monoclinic form, space group C2, a=65.6, b=95.0, c=41.2, ?=119.2°. A crystal of ˜0.2×0.2×0.5 mm grown from bulk solution diffracted to ˜3.5 Å.

Forsythe, Elizabeth L.; Snell, Edward H.; Malone, Christine C.; Pusey, Marc L.

1999-01-01

459

Precipitation of heavy metals from coal ash leachate using biogenic hydrogen sulfide generated from FGD gypsum.  

PubMed

Investigations were undertaken to utilize flue gas desulfurization (FGD) gypsum for the treatment of leachate from the coal ash (CA) dump sites. Bench-scale investigations consisted of three main steps namely hydrogen sulfide (H(2)S) production by sulfate reducing bacteria (SRB) using sulfate from solubilized FGD gypsum as the electron acceptor, followed by leaching of heavy metals (HMs) from coal bottom ash (CBA) and subsequent precipitation of HMs using biologically produced sulfide. Leaching tests of CBA carried out at acidic pH revealed the existence of several HMs such as Cd, Cr, Hg, Pb, Mn, Cu, Ni and Zn. Molasses was used as the electron donor for the biological sulfate reduction (BSR) process which produced sulfide rich effluent with concentration up to 150 mg/L. Sulfide rich effluent from the sulfate reduction process was used to precipitate HMs as metal sulfides from CBA leachate. HM removal in the range from 40 to 100% was obtained through sulfide precipitation. PMID:23168629

Jayaranjan, Madawala Liyanage Duminda; Annachhatre, Ajit P

2013-01-01

460

Sulfate induced heave in lime stabilized soil  

E-print Network

The addition of hydrated lime to clay soils is one of the most common methods of soil stabilization. However, when sulfates are present in the soil, the calcium in the lime reacts with the sulfates to form ettringite, an expandable mineral...

Bredenkamp, Sanet

2012-06-07

461

21 CFR 582.1131 - Aluminum sodium sulfate.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Aluminum sodium sulfate. 582.1131 Section 582...General Purpose Food Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of...

2011-04-01

462

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2012-04-01

463

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2013-04-01

464

21 CFR 182.1131 - Aluminum sodium sulfate.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Aluminum sodium sulfate. 182.1131 Section 182...Purpose GRAS Food Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of...

2011-04-01

465

21 CFR 182.1131 - Aluminum sodium sulfate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum sodium sulfate. 182.1131 Section 182...Purpose GRAS Food Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of...

2013-04-01

466

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2011-04-01

467

21 CFR 182.1131 - Aluminum sodium sulfate.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2009-04-01 true Aluminum sodium sulfate. 182.1131 Section 182...Purpose GRAS Food Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of...

2010-04-01

468

21 CFR 582.1131 - Aluminum sodium sulfate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum sodium sulfate. 582.1131 Section 582...General Purpose Food Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of...

2013-04-01

469

21 CFR 582.1131 - Aluminum sodium sulfate.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Aluminum sodium sulfate. 582.1131 Section 582...General Purpose Food Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of...

2014-04-01

470

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2010-04-01

471

21 CFR 182.1131 - Aluminum sodium sulfate.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Aluminum sodium sulfate. 182.1131 Section 182...Purpose GRAS Food Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of...

2014-04-01

472

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2014-04-01

473

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2012-04-01

474

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2009-04-01 true Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2010-04-01

475

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2011-04-01

476

21 CFR 582.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Aluminum ammonium sulfate. 582.1127 Section...General Purpose Food Additives § 582.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2014-04-01

477

21 CFR 582.1131 - Aluminum sodium sulfate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Aluminum sodium sulfate. 582.1131 Section 582...General Purpose Food Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of...

2012-04-01

478

21 CFR 182.1131 - Aluminum sodium sulfate.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Aluminum sodium sulfate. 182.1131 Section 182...Purpose GRAS Food Substances § 182.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of...

2012-04-01

479

21 CFR 182.1127 - Aluminum ammonium sulfate.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Aluminum ammonium sulfate. 182.1127 Section...Purpose GRAS Food Substances § 182.1127 Aluminum ammonium sulfate. (a) Product. Aluminum ammonium sulfate. (b) Conditions...

2013-04-01

480

21 CFR 582.1131 - Aluminum sodium sulfate.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Aluminum sodium sulfate. 582.1131 Section 582...General Purpose Food Additives § 582.1131 Aluminum sodium sulfate. (a) Product. Aluminum sodium sulfate. (b) Conditions of...

2010-04-01

481

40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.  

Code of Federal Regulations, 2010 CFR

...dialkyldiethylenetriamine, alkyl sulfate salt. 721.2420 Section 721.2420 ...dialkyldiethylenetriamine, alkyl sulfate salt. (a) Chemical substance and significant...dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject to...

2010-07-01

482

40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.  

Code of Federal Regulations, 2014 CFR

...dialkyldiethylenetriamine, alkyl sulfate salt. 721.2420 Section 721.2420 ...dialkyldiethylenetriamine, alkyl sulfate salt. (a) Chemical substance and significant...dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject to...

2014-07-01

483

40 CFR 721.2420 - Alkoxylated dialkyldiethylenetriamine, alkyl sulfate salt.  

Code of Federal Regulations, 2013 CFR

...dialkyldiethylenetriamine, alkyl sulfate salt. 721.2420 Section 721.2420 ...dialkyldiethylenetriamine, alkyl sulfate salt. (a) Chemical substance and significant...dialkyldiethylenetriamine, alkyl sulfate salt (PMN P-91-288) is subject to...

2013-07-01